David Domingo Sabatini, Ph.D.

Philip Siekevitz: Bridging biochemistry and cell biology
Sabatini, David D
2010 Apr 5;189(1):3-5, Journal of cell biology
Philip Siekevitz, an Emeritus Professor at the Rockefeller University who made pioneering contributions to the development of modern cell biology, passed away on December 5th, 2009. He was a creative and enthusiastic scientist, as well as a great experimentalist who throughout his lifetime transmitted the joy of practicing science and the happiness that comes with the acquisition of new knowledge. He was a man of great integrity, with a thoroughly engaging personality and a humility not often found in people of his talent
— id: 115356, year: 2010, vol: 189, page: 3, stat: Journal Article,

Wnt signaling requires sequestration of glycogen synthase kinase 3 inside multivesicular endosomes
Taelman, Vincent F; Dobrowolski, Radoslaw; Plouhinec, Jean-Louis; Fuentealba, Luis C; Vorwald, Peggy P; Gumper, Iwona; Sabatini, David D; De Robertis, Edward M
2010 Dec 23;143(7):1136-1148, Cell
Canonical Wnt signaling requires inhibition of Glycogen Synthase Kinase 3 (GSK3) activity, but the molecular mechanism by which this is achieved remains unclear. Here, we report that Wnt signaling triggers the sequestration of GSK3 from the cytosol into multivesicular bodies (MVBs), so that this enzyme becomes separated from its many cytosolic substrates. Endocytosed Wnt colocalized with GSK3 in acidic vesicles positive for endosomal markers. After Wnt addition, endogenous GSK3 activity decreased in the cytosol, and GSK3 became protected from protease treatment inside membrane-bounded organelles. Cryoimmunoelectron microscopy showed that these corresponded to MVBs. Two proteins essential for MVB formation, HRS/Vps27 and Vps4, were required for Wnt signaling. The sequestration of GSK3 extended the half-life of many other proteins in addition to beta-Catenin, including an artificial Wnt-regulated reporter protein containing GSK3 phosphorylation sites. We conclude that multivesicular endosomes are essential components of the Wnt signal-transduction pathway
— id: 133841, year: 2010, vol: 143, page: 1136, stat: Journal Article,

Involvement of vps33a in the fusion of uroplakin-degrading multivesicular bodies with lysosomes
Guo, Xuemei; Tu, Liyu; Gumper, Iwona; Plesken, Heide; Novak, Edward K; Chintala, Sreenivasulu; Swank, Richard T; Pastores, Gregory; Torres, Paola; Izumi, Tetsuro; Sun, Tung-Tien; Sabatini, David D; Kreibich, Gert
2009 Sep;10(9):1350-1361, Traffic
The apical surface of the terminally differentiated mouse bladder urothelium is largely covered by urothelial plaques, consisting of hexagonally packed 16-nm uroplakin particles. These plaques are delivered to the cell surface by fusiform vesicles (FVs) that are the most abundant cytoplasmic organelles. We have analyzed the functional involvement of several proteins in the apical delivery and endocytic degradation of uroplakin proteins. Although FVs have an acidified lumen and Rab27b, which localizes to these organelles, is known to be involved in the targeting of lysosome-related organelles (LROs), FVs are CD63 negative and are therefore not typical LROs. Vps33a is a Sec1-related protein that plays a role in vesicular transport to the lysosomal compartment. A point mutation in mouse Vps33a (Buff mouse) causes albinism and bleeding (Hermansky-Pudlak syndrome) because of abnormalities in the trafficking of melanosomes and platelets. These Buff mice showed a novel phenotype observed in urothelial umbrella cells, where the uroplakin-delivering FVs were almost completely replaced by Rab27b-negative multivesicular bodies (MVBs) involved in uroplakin degradation. MVB accumulation leads to an increase in the amounts of uroplakins, Lysosomal-associated membrane protein (LAMP)-1/2, and the activities of beta-hexosaminidase and beta-glucocerebrosidase. These results suggest that FVs can be regarded as specialized secretory granules that deliver crystalline arrays of uroplakins to the cell surface, and that the Vps33a mutation interferes with the fusion of MVBs with mature lysosomes thus blocking uroplakin degradation
— id: 101636, year: 2009, vol: 10, page: 1350, stat: Journal Article,

Plakoglobin is required for effective intermediate filament anchorage to desmosomes
Acehan, Devrim; Petzold, Christopher; Gumper, Iwona; Sabatini, David D; Muller, Eliane J; Cowin, Pamela; Stokes, David L
2008 Nov;128(11):2665-2675, Journal of investigative dermatology
Desmosomes are adhesive junctions that provide mechanical coupling between cells. Plakoglobin (PG) is a major component of the intracellular plaque that serves to connect transmembrane elements to the cytoskeleton. We have used electron tomography and immunolabeling to investigate the consequences of PG knockout on the molecular architecture of the intracellular plaque in cultured keratinocytes. Although knockout keratinocytes form substantial numbers of desmosome-like junctions and have a relatively normal intercellular distribution of desmosomal cadherins, their cytoplasmic plaques are sparse and anchoring of intermediate filaments is defective. In the knockout, beta-catenin appears to substitute for PG in the clustering of cadherins, but is unable to recruit normal levels of plakophilin-1 and desmoplakin to the plaque. By comparing tomograms of wild type and knockout desmosomes, we have assigned particular densities to desmoplakin and described their interaction with intermediate filaments. Desmoplakin molecules are more extended in wild type than knockout desmosomes, as if intermediate filament connections produced tension within the plaque. On the basis of our observations, we propose a particular assembly sequence, beginning with cadherin clustering within the plasma membrane, followed by recruitment of plakophilin and desmoplakin to the plaque, and ending with anchoring of intermediate filaments, which represents the key to adhesive strength
— id: 93304, year: 2008, vol: 128, page: 2665, stat: Journal Article,

Obituary: George Palade 1912-2008
Sabatini, David D
2008 Dec;10(12):1374-1374, Nature cell biology
— id: 111648, year: 2008, vol: 10, page: 1374, stat: Journal Article,

In awe of subcellular complexity: 50 years of trespassing boundaries within the cell
Sabatini, David D
2005 ;21:1-33, Annual review of cell & developmental biology
In this review I describe the several stages of my research career, all of which were driven by a desire to understand the basic mechanisms responsible for the complex and beautiful organization of the eukaryotic cell. I was originally trained as an electron microscopist in Argentina, and my first major contribution was the introduction of glutaraldehyde as a fixative that preserved the fine structure of cells, which opened the way for cytochemical studies at the EM level. My subsequent work on membrane-bound ribosomes illuminated the process of cotranslational translocation of polypeptides across the ER membrane and led to the formulation, with Gunter Blobel, of the signal hypothesis. My later studies with many talented colleagues contributed to an understanding of ER structure and function and aspects of the mechanisms that generate and maintain the polarity of epithelial cells. For this work my laboratory introduced the now widely adopted Madin-Darby canine kidney (MDCK) cell line, and demonstrated the polarized budding of envelope viruses from those cells, providing a powerful new system that further advanced the field of protein traffic
— id: 61367, year: 2005, vol: 21, page: 1, stat: Journal Article,

Rab27b is associated with fusiform vesicles and may be involved in targeting uroplakins to urothelial apical membranes
Chen, Yanru; Guo, Xuemei; Deng, Fang-Ming; Liang, Feng-Xia; Sun, Wenyu; Ren, Mindong; Izumi, Tetsuro; Sabatini, David D; Sun, Tung-Tien; Kreibich, Gert
2003 Nov 25;100(24):14012-14017, Proceedings of the National Academy of Sciences of the United States of America
The terminally differentiated umbrella cells of bladder epithelium contain unique cytoplasmic organelles, the fusiform vesicles, which deliver preassembled crystalline arrays of uroplakin proteins to the apical cell surface of urothelial umbrella cells. We have investigated the possible role of Rab proteins in this delivery process, and found Rab27b to be expressed at an extraordinary high level (0.1% of total protein) in urothelium, whereas Rab27b levels were greatly reduced (to <5% of normal urothelium) in cultured urothelial cells, which synthesized only small amounts of uroplakins and failed to form fusiform vesicles. Immuno-electron microscopy showed that Rab27b was associated with the cytoplasmic face of the fusiform vesicles, but not with that of the apical plasma membrane. The association of Rab27b with fusiform vesicles and its differentiation-dependent expression suggest that this Rab protein plays a role in regulating the delivery of fusiform vesicles to the apical plasma membrane of umbrella cells
— id: 42018, year: 2003, vol: 100, page: 14012, stat: Journal Article,

GLUT4 retention in adipocytes requires two intracellular insulin-regulated transport steps
Zeigerer, Anja; Lampson, Michael A; Karylowski, Ola; Sabatini, David D; Adesnik, Milton; Ren, Mindong; McGraw, Timothy E
2002 Jul;13(7):2421-2435, Molecular biology of the cell
Insulin regulates glucose uptake into fat and muscle by modulating the distribution of the GLUT4 glucose transporter between the surface and interior of cells. The GLUT4 trafficking pathway overlaps with the general endocytic recycling pathway, but the degree and functional significance of the overlap are not known. In this study of intact adipocytes, we demonstrate, by using a compartment-specific fluorescence-quenching assay, that GLUT4 is equally distributed between two intracellular pools: the transferrin receptor-containing endosomes and a specialized compartment that excludes the transferrin receptor. These pools of GLUT4 are in dynamic communication with one another and with the cell surface. Insulin-induced redistribution of GLUT4 to the surface requires mobilization of both pools. These data establish a role for the general endosomal system in the specialized, insulin-regulated trafficking of GLUT4. Trafficking through the general endosomal system is regulated by rab11. Herein, we show that rab11 is required for the transport of GLUT4 from endosomes to the specialized compartment and for the insulin-induced translocation to the cell surface, emphasizing the importance of the general endosomal pathway in the specialized trafficking of GLUT4. Based on these findings we propose a two-step model for GLUT4 trafficking in which the general endosomal recycling compartment plays a specialized role in the insulin-regulated traffic of GLUT4. This compartment-based model provides the framework for understanding insulin-regulated trafficking at a molecular level
— id: 55808, year: 2002, vol: 13, page: 2421, stat: Journal Article,

Diabetes mellitus and exocrine pancreatic dysfunction in perk-/- mice reveals a role for translational control in secretory cell survival
Harding HP; Zeng H; Zhang Y; Jungries R; Chung P; Plesken H; Sabatini DD; Ron D
2001 Jun;7(6):1153-1163, Molecular cell
The protein kinase PERK couples protein folding in the endoplasmic reticulum (ER) to polypeptide biosynthesis by phosphorylating the alpha subunit of eukaryotic translation initiation factor 2 (eIF2alpha), attenuating translation initiation in response to ER stress. PERK is highly expressed in mouse pancreas, an organ active in protein secretion. Under physiological conditions, PERK was partially activated, accounting for much of the phosphorylated eIF2alpha in the pancreas. The exocrine and endocrine pancreas developed normally in Perk-/- mice. Postnatally, ER distention and activation of the ER stress transducer IRE1alpha accompanied increased cell death and led to progressive diabetes mellitus and exocrine pancreatic insufficiency. These findings suggest a special role for translational control in protecting secretory cells from ER stress
— id: 21161, year: 2001, vol: 7, page: 1153, stat: Journal Article,

A role of a rab11BP-AP1 adaptor interaction in vesicle budding from recycling endosomes
Zhou, L; Li, J; Ma, JP; Sabatini, DD; Adesnik, M; Ren, MD
2001 NOV ;12(1):344A-344A, Molecular biology of the cell
— id: 55363, year: 2001, vol: 12, page: 344A, stat: Journal Article,

Localization of ribophorin II to the endoplasmic reticulum involves both its transmembrane and cytoplasmic domains
Fu J; Pirozzi G; Sanjay A; Levy R; Chen Y; De Lemos-Chiarandini C; Sabatini D; Kreibich G
2000 Apr;79(4):219-228, European journal of cell biology
Proteins that are concentrated in specific compartments of the endomembrane system in order to exert their organelle-specific function must possess specific localization signals that prevent their transport to distal regions of the exocytic pathway. Some resident proteins of the endoplasmic reticulum (ER) that are known to escape with low efficiency from this organelle to a post ER compartment are recognized by a recycling receptor and brought back to their site of residence. Other ER proteins, however, appear to be retained in the ER by mechanisms that operate in the organelle itself. The mammalian oligosaccharyltransferase (OST) is a protein complex that effects the cotranslational N-glycosylation of newly synthesized polypeptides, and is composed of at least four rough ER-specific membrane proteins: ribophorins I and II (RI and RII), OST48, and Dadl. The mechanism(s) by which the subunits of this complex are retained in the ER are not well understood. In an effort to identify the domains within RII responsible for its ER localization we have studied the fate of chimeric proteins in which one or more RII domains were replaced by the corresponding ones of the Tac antigen, the latter being a well characterized plasma membrane protein that lacks intrinsic ER retention signals and serves to provide a neutral framework for the identification of retention signals in other proteins. We found that the luminal domain of RII by itself does not contain retention information, while the cytoplasmic and transmembrane domains contain independent ER localization signals. We also show that the retention function of the transmembrane domain is strengthened by the presence of a flanking luminal region consisting of 15 amino acids
— id: 11683, year: 2000, vol: 79, page: 219, stat: Journal Article,

In vitro generation from the trans-Golgi network of coatomer-coated vesicles containing sialylated vesicular stomatitis virus-G protein
Simon JP; Ivanov IE; Adesnik M; Sabatini DD
2000 Apr;20(4):437-454, Methods
We describe an in vitro system in which post-Golgi vesicles containing metabolically labeled, sialylated, vesicular stomatitis virus (VSV) G protein molecules (VSV-G) are produced from the trans-Golgi network (TGN) of an isolated Golgi membrane fraction. This fraction is prepared from VSV-infected Madin-Darby canine kidney (MDCK) cells in which the (35)S-labeled viral envelope glycoprotein was allowed to accumulate in the trans-Golgi network during a prolonged incubation at 20 degrees C. The vesicles produced in this system are separated from the remnant Golgi membranes by differential centrifugation or by velocity sedimentation in a sucrose gradient. Vesicle production, quantified as the percentage of labeled VSV-G released from the Golgi membranes, is optimal at 37 degrees C and does not occur below 20 degrees C. It requires GTP and the small GTP-binding protein Arf (ADP-ribosylation factor), as well as coat protein type I (COPI) coat components (coatomer) and vesicle scission factors-one of which corresponds to the phosphatidylinositol transfer protein (PITP). Formation of the vesicles does not require GTP hydrolysis which, however, is necessary for their uncoating. Thus, vesicles generated in the presence of the nonhydrolyzable GTP analogs, GTPgammaS or GMP-PNP, retain a coatomer coat visible in the electron microscope, sediment more rapidly in sucrose density gradients than those generated with ATP or GTP, and can be captured with anticoatomerantibodies. The process of coatomer-coated vesicle formation from the TGN can be dissected into two distinct sequential phases, corresponding to coat assembly/bud formation and vesicle scission. The first phase is completed when Golgi fractions are incubated with cytosolic proteins and nonhydrolyzable GTP analogs at 20 degrees C. The scission phase, which leads to vesicle release, takes place when coated Golgi membranes, recovered after phase I, are incubated at higher temperatures in the presence of cytosolic proteins. The scission phase does not take place if protein kinase C inhibitors are added during the first phase, even though these inhibitors do not prevent membrane coating and bud formation. The phosphorylating activity of a protein kinase C, however, plays no role in vesicle formation, since this process does not require ATP.
— id: 11801, year: 2000, vol: 20, page: 437, stat: Journal Article,

Rab11 stimulates fluid phase and mannose receptor-mediated endocytosis by regulating endosome fusion
Aballay, A; Damiani, MT; Ren, MD; Adesnik, M; Mayorga, LS; Sabatini, DD; Stahl, PD; Colombo, MI
1999 ;10(4):1284-1284, Molecular biology of the cell
— id: 104641, year: 1999, vol: 10, page: 1284, stat: Journal Article,

Identification of a new Pyk2 target protein with Arf-GAP activity
Andreev J; Simon JP; Sabatini DD; Kam J; Plowman G; Randazzo PA; Schlessinger J
1999 Mar;19(3):2338-2350, Molecular & cellular biology
Protein tyrosine kinase Pyk2 is activated by a variety of G-protein-coupled receptors and by extracellular signals that elevate intracellular Ca2+ concentration. We have identified a new Pyk2 binding protein designated Pap. Pap is a multidomain protein composed of an N-terminal alpha-helical region with a coiled-coil motif, followed by a pleckstrin homology domain, an Arf-GAP domain, an ankyrin homology region, a proline-rich region, and a C-terminal SH3 domain. We demonstrate that Pap forms a stable complex with Pyk2 and that activation of Pyk2 leads to tyrosine phosphorylation of Pap in living cells. Immunofluorescence experiments demonstrate that Pap is localized in the Golgi apparatus and at the plasma membrane, where it is colocalized with Pyk2. In addition, in vitro recombinant Pap exhibits strong GTPase-activating protein (GAP) activity towards the small GTPases Arf1 and Arf5 and weak activity towards Arf6. Addition of recombinant Pap protein to Golgi preparations prevented Arf-dependent generation of post-Golgi vesicles in vitro. Moreover, overexpression of Pap in cultured cells reduced the constitutive secretion of a marker protein. We propose that Pap functions as a GAP for Arf and that Pyk2 may be involved in regulation of vesicular transport through its interaction with Pap
— id: 7298, year: 1999, vol: 19, page: 2338, stat: Journal Article,

George E. Palade: charting the secretory pathway
Sabatini DD
1999 Oct;9(10):413-417, Trends in cell biology
— id: 11963, year: 1999, vol: 9, page: 413, stat: Journal Article,

Identification of a putative effector protein for rab11 that participates in transferrin recycling
Zeng J; Ren M; Gravotta D; De Lemos-Chiarandini C; Lui M; Erdjument-Bromage H; Tempst P; Xu G; Shen TH; Morimoto T; Adesnik M; Sabatini DD
1999 Mar 16;96(6):2840-2845, Proceedings of the National Academy of Sciences of the United States of America
We have identified and cloned the cDNA for a 912-aa protein, rab11BP, that interacts with the GTP-containing active form of rab11, a GTP-binding protein that plays a critical role in receptor recycling. Although rab11BP is primarily cytosolic, a significant fraction colocalizes with rab11 in endosomal membranes of both the sorting and recycling subcompartments. In vitro binding of rab11 to native rab11BP requires partial denaturation of the latter to expose an internal binding site located between residues 334 and 504 that is apparently masked by the C-terminal portion of the protein, which includes six repeats known as WD40 domains. Within the cell, rab11BP must undergo a conformational change in which the rab11-binding site becomes exposed, because when coexpressed with rab11 in transfected cells the two proteins formed abundant complexes in association with membranes. Furthermore, although overexpression of rab11BP did not affect transferrin recycling, overexpression of a truncated form of the protein, rab11BP(1-504), that includes the rab11-binding site but lacks the WD40 domains inhibited recycling as strongly as does a dominant negative rab11 mutant protein that does not bind GTP. Strikingly, the inhibition caused by the truncated rab11BP was prevented completely when the cells also expressed a C-terminally deleted, nonprenylatable form of rab11 that, by itself, has no effect on recycling. We propose that rab11BP is an effector for rab11, whose association with this GTP-binding protein is dependent on the action of another membrane-associated factor that promotes the unmasking of the rab11-binding site in rab11BP
— id: 56409, year: 1999, vol: 96, page: 2840, stat: Journal Article,

Hydrolysis of GTP on rab11 is required for the direct delivery of transferrin from the pericentriolar recycling compartment to the cell surface but not from sorting endosomes
Ren M; Xu G; Zeng J; De Lemos-Chiarandini C; Adesnik M; Sabatini DD
1998 May 26;95(11):6187-6192, Proceedings of the National Academy of Sciences of the United States of America
Rab11 is a small GTP-binding protein that in cultured mammalian cells has been shown to be concentrated in the pericentriolar endosomal recycling compartment and to play a key role in passage of the recycling transferrin receptor through that compartment [Ullrich, O., Reinsch, S., Urbe, S., Zerial, M. & Parton, R. G. (1996) J. Cell Biol. 135, 913-924]. To obtain insights into the site(s) of action of rab11 within the recycling pathway, we have now compared the effects on recycling at 37 degreesC of overexpression of wild-type rab11 and various mutant forms of this protein in cells that had been loaded with transferrin at either 37 degreesC or 16 degreesC. We show that incubation at 16 degreesC blocks passage of endocytosed transferrin into the recycling compartment and that, whereas the rab11 dominant negative mutant form (S25N) inhibits transferrin recycling after interiorization at either temperature, the wild-type rab11 and constitutively active mutant (Q70L) have no inhibitory effect on the recycling of molecules that were interiorized at 16 degreesC. This differential inhibitory effect shows that two distinct pathways for recycling are followed by the bulk of the transferrin molecules interiorized at the two different temperatures. The incapacity of the constitutively active form of rab11 (Q70L) to inhibit recycling of molecules interiorized at 16 degreesC is consistent with their recycling taking place directly from sorting endosomes, in a process that does not require hydrolysis of GTP on rab11. The fact that the dominant negative (S25N) form of rab11 inhibits recycling of molecules interiorized at both temperatures indicates that activation of rab11 by GTP is required for exit of transferrin from sorting endosomes, regardless of whether this exit is toward the recycling compartment or directly to the plasma membrane
— id: 57335, year: 1998, vol: 95, page: 6187, stat: Journal Article,

Rab11PB, a novel Rab11 effector, regulates transferrin recycling
Ren, M; Zeng, J; Gravotta, D; Xu, G; De Lemos-Chiarandini, C; Shen, T; Morimoto, T; Adesnik, M; Sabatini, DD
1998 ;9(11):2693-2693, Molecular biology of the cell
— id: 104642, year: 1998, vol: 9, page: 2693, stat: Journal Article,

An essential role for the phosphatidylinositol transfer protein in the scission of coatomer-coated vesicles from the trans-Golgi network
Simon JP; Morimoto T; Bankaitis VA; Gottlieb TA; Ivanov IE; Adesnik M; Sabatini DD
1998 Sep 15;95(19):11181-11186, Proceedings of the National Academy of Sciences of the United States of America
We identified the phosphatidylinositol transfer protein (PITP) as being responsible for a powerful latent, nucleotide-independent, Golgi-vesiculating activity that is present in the cytosol but is only manifested as an uncontrolled activity in a cytosolic protein subfraction, in which it is separated from regulatory components that appear to normally limit its action to the scission of COPI-coated buds from trans-Golgi network membranes. A specific anti-PITP antibody that recognizes the two mammalian PITP isoforms fully inhibited the capacity of the cytosol to support normal vesicle generation as well as the uncontrolled vesiculating activity manifested by the cytosolic protein subfraction. The phosphatidylinositol- (PI) loaded form of the yeast PITP, Sec14p, but not the phosphatidylcholine- (PC) loaded form of the protein, was capable of substituting for the cytosolic subfraction in promoting the scission of coated buds from the trans-Golgi network. At higher concentration, however, Sec14p, when loaded with PI, but not with PC or phosphatidylglycerol, caused by itself an indiscriminate vesiculation of uncoated Golgi membranes that could be suppressed by PC-Sec14p, which also suppresses the uncontrolled vesiculation caused by the cytosolic subfraction. We propose that, by delivering PI to specific sites in the Golgi membrane near the necks of coated buds, PITP induces local changes in the organization of the lipid bilayer, possibly involving PI metabolites, that triggers the fusion of the ectoplasmic faces of the Golgi membrane necessary for the scission of COPI-coated vesicles
— id: 57548, year: 1998, vol: 95, page: 11181, stat: Journal Article,

Coatomer, but not P200/myosin II, is required for the in vitro formation of trans-Golgi network-derived vesicles containing the envelope glycoprotein of vesicular stomatitis virus
Simon JP; Shen TH; Ivanov IE; Gravotta D; Morimoto T; Adesnik M; Sabatini DD
1998 Feb 3;95(3):1073-1078, Proceedings of the National Academy of Sciences of the United States of America
Using a cytosol and nucleotide dependent assay that we previously developed, we have investigated the requirement for coat proteins in the in vitro production of trans-Golgi network (TGN)-derived vesicles from a Madin-Darby canine kidney (MDCK) cell Golgi fraction that contains the 35S-labeled, terminally glycosylated, envelope glycoprotein of vesicular stomatitis virus (VSV-G) accumulated in the TGN. We found that the TGN-derived vesicles, like those involved in intra-Golgi transport and in retrograde transport to the endoplasmic reticulum, contain a coatomer coat and that coatomer is required for their formation. Thus, after they are produced with GTPgammaS, the coated vesicles could be captured on beads containing anticoatomer antibody. Moreover, a cytosolic protein fraction depleted of coatomer could not support vesicle formation but it did so after purified coatomer was added. We also determined that P200/myosin II does not play an essential role in the in vitro generation of TGN-derived vesicles. Thus, removal of this protein from the cytosol, by differential salt precipitation or binding to phalloidin-induced actin filaments, had no effect on vesicle generation. Nevertheless, immunodepletion of cytosol using the anti-P200/myosin II AD7 antibody abolished vesicle generation and that antibody was capable of effectively immunocapturing coated vesicles, even when these were generated in the absence of P200/myosin II. These effects, however, are explained by the unexpected finding that the AD7 antibody interacts with undenatured coatomer
— id: 57547, year: 1998, vol: 95, page: 1073, stat: Journal Article,

An essential role for the phosphatidylinositol transfer protein (PITP) in the scission of COPI-coated vesicles from the TGN
Simon, JP; Morimoto, T; Bankaitis, VA; Gottlieb, TA; Ivanov, IE; Adesnik, M; Sabatini, DD
1998 NOV ;9(11):207A-207A, Molecular biology of the cell
— id: 53645, year: 1998, vol: 9, page: 207A, stat: Journal Article,

Rab8 is a specific substrate for the Rab8ip/GC kinase
Ren, M; Lake, R; Xu, G; Adesnik, M; Sabatini, DD
1997 NOV ;8(5):2447-2447, Molecular biology of the cell
— id: 53171, year: 1997, vol: 8, page: 2447, stat: Journal Article,

Rab11-GTP is required early in the endocytic pathway but hydrolysis of its GTP is necessary only for return of receptors from the recycling compartment to the cell surface
Ren, M; Xu, G; DeLemosChiarandini, C; Adesnik, M; Sabatini, DD
1997 NOV ;8(5):2460-2460, Molecular biology of the cell
— id: 53172, year: 1997, vol: 8, page: 2460, stat: Journal Article,

Coatomer is required for the in vitro formation of TGN-derived vesicles containing VSV-G protein
Simon, JP; Shen, TH; Ivanov, I; Gravotta, D; Morimoto, T; Adesnik, M; Sabatini, DD
1997 NOV ;8(5):1129-1129, Molecular biology of the cell
— id: 53165, year: 1997, vol: 8, page: 1129, stat: Journal Article,

Cell-free reconstitution of the transport of viral glycoproteins from the TGN to the basolateral plasma membrane of MDCK cells
Mayer A; Ivanov IE; Gravotta D; Adesnik M; Sabatini DD
1996 Jul;109(Pt 7):1667-1676, Journal of cell science
An in vitro system to study the transport of plasma membrane proteins from the TGN to the basolateral plasma membrane of polarized MDCK cells has been developed in which purified cell fractions are combined and transport between them is studied under controlled conditions. In this system, a donor Golgi fraction derived from VSV or influenza virus-infected MDCK cells, in which 35S-labeled viral glycoproteins were allowed to accumulate in the TGN during a low temperature block, is incubated with purified immobilized basolateral plasma membranes that have their cytoplasmic face exposed and are obtained by shearing-lysis of MDCK monolayers grown on cytodex beads. Approximately 15-30% of the labeled glycoprotein molecules are transferred from the Golgi fraction to the acceptor plasma membranes and are recovered with the sedimentable (1 g) beads. Transport is temperature, energy and cytosol dependent, and is abolished by alkylation of SH groups and inhibited by the presence of GTP-gamma-S, which implicates GTP-binding proteins and the requirement for GTP hydrolysis in one or more stages of the transport process. Endo H-resistant glycoprotein molecules that had traversed the medial region of the Golgi apparatus are preferentially transported and their luminal domains become accessible to proteases, indicating that membrane fusion with the plasma membrane takes place in the in vitro system. Mild proteolysis of the donor or acceptor membranes abolishes transport, suggesting that protein molecules exposed on the surface of these membranes are involved in the formation and consumption of transport intermediates, possibly as addressing and docking proteins, respectively. Surprisingly, both VSV-G and influenza HA were transported with equal efficiencies to the basolateral acceptor membranes. However, low concentrations of a microtubular protein fraction preferentially inhibited the transport of HA, although this effect was not abolished by microtubule depolymerizing agents. This system shows great promise for elucidating the mechanisms that effect the proper sorting of plasma membrane proteins in the TGN and their subsequent targeting to the appropriate acceptor membrane
— id: 12585, year: 1996, vol: 109, page: 1667, stat: Journal Article,

In its active form, the GTP-binding protein rab8 interacts with a stress-activated protein kinase
Ren M; Zeng J; De Lemos-Chiarandini C; Rosenfeld M; Adesnik M; Sabatini DD
1996 May 14;93(10):5151-5155, Proceedings of the National Academy of Sciences of the United States of America
Rab8 is a small GTP-binding protein that plays a role in vesicular transport from the trans-Golgi network to the basolateral plasma membrane in polarized epithelial cells (MDCK), and to the dendritic surface in hippocampal neurons. As is the case for most other rab proteins, the precise molecular interactions by which rab8 carries out its function remain to be elucidated. Here we report the identification and the complete cDNA-derived amino acid sequence of a murine rab8-interacting protein (rab8ip) that specifically interacts with rab8 in a GTP-dependent manner. Rab8ip displays 93% identity with the GC kinase, a serine/threonine protein kinase recently identified in human lymphoid tissue that is activated in the stress response. Like the GC kinase, rab8ip has protein kinase activity manifested by autophosphorylation and phosphorylation of the classical serine/threonine protein kinase substrates, myelin basic protein and casein. When coexpressed in transfected 293T cells, rab8 and the rab8ip/GC kinase formed a complex that could be recovered by immunoprecipitation with antibodies to rab8. Cell fractionation and immunofluorescence analyses indicate that in MDCK cells endogenous rab8ip is present both in the cytosol and as a peripheral membrane protein concentrated in the Golgi region and basolateral plasma membrane domains, sites where rab8 itself is also located. In light of recent evidence that rab proteins may act by promoting the stabilization of SNARE complexes, the specific GTP-dependent association of rab8 with the rab8ip/GC kinase raises the possibility that rab-regulated protein phosphorylation is important for vesicle targeting or fusion. Moreover, the rab8ip/GC kinase may serve to modulate secretion in response to stress stimuli
— id: 57507, year: 1996, vol: 93, page: 5151, stat: Journal Article,

Mechanism of formation of post Golgi vesicles from TGN membranes: Arf-dependent coat assembly and PKC-regulated vesicle scission
Sabatini DD; Adesnik M; Ivanov IE; Simon JP
1996 Dec;20(3):287-300, Biocell
We have developed an experimental system that utilizes purified Golgi fractions obtained from virus infected infected MDCK cells to reproduce in vitro the process of vesicle generation in the trans Golgi network, an important site for the sorting of proteins addressed to the plasma membrane, secretory vesicles, or lysosomes. Using an integrated biochemical and electron microscopic approach, we have shown that the formation of post Golgi vesicles carrying proteins destined to both plasma membrane domains of epithelial cells requires the activation of an ArF-like GTP-binding protein that serves to promote the assembly of the protein coat necessary to deform the donor membrane and generate a vesicle. The formation of the post Golgi vesicles also requires the participation of a Golgi membrane-associated Protein Kinase C, but not its phosphorylating activity. Other authors have shown that this is also the case for the PKC activation of the enzyme phospholipase D, which generates phosphatidic acid from phosphatidyl choline and may be involved in remodeling of membranes. We have been able to dissect the process of post Golgi vesicle generation into two sequential stages, one of coat assembly and bud formation, and a subsequent one of vesicle scission. The first stage can occur at 20 degrees C and requires the activation of the Arf protein necessary for coat assembly. The second stage does not require nucleotides or an energy supply, but requires cytosolic proteins, and in particular, an NEM sensitive membrane scission promoting activity that operates only at a higher temperature of incubation. Because various PKC inhibitors blocked vesicle scission without preventing bud formation, we propose that the PKC is required for the activation of a PLD in the TGN, which leads to remodeling of the donor membrane and the severing of connections between the emerging vesicles and the membranes
— id: 12450, year: 1996, vol: 20, page: 287, stat: Journal Article,

Identification of domains involved in the retention of ribophorin II in the endoplasmic reticulum
Sanjay, A; Pirozzi, G; DeLemosChiarandini, C; Sabatini, DD; Kreibich, G
1996 DEC ;7(3):3584-3584, Molecular biology of the cell
— id: 53361, year: 1996, vol: 7, page: 3584, stat: Journal Article,

The production of post-Golgi vesicles requires a protein kinase C-like molecule, but not its phosphorylating activity
Simon JP; Ivanov IE; Adesnik M; Sabatini DD
1996 Oct;135(2):355-370, Journal of cell biology
We have recently described a system that recreates in vitro the generation of post-Golgi vesicles from purified Golgi fractions obtained from virus-infected MDCK cells in which the vesicular stomatitis virus-G envelope glycoprotein had been allowed to accumulate in vivo in the TGN. Vesicle formation, monitored by the release of the viral glycoprotein, was shown to require the activation of a GTP-binding ADP ribosylation factor (ARF) protein that promotes the assembly of a vesicle coat in the TGN, and to be regulated by a Golgi-associated protein kinase C (PKC)-like activity. We have now been able to dissect the process of post-Golgi vesicle generation into two sequential stages, one of coat assembly and bud formation, and another of vesicle scission, neither of which requires an ATP supply. The first stage can occur at 20 degrees C, and includes the GTP-dependent activation of the ARF protein, which can be effected by the nonhydrolyzable nucleotide analogue GTP gamma S, whereas the second stage is nucleotide independent and can only occur at a higher temperature of incubation. Cytosolic proteins are required for the vesicle scission step and they cannot be replaced by palmitoyl CoA, which is known to promote, by itself, scission of the coatomer-coated vesicles that mediate intra-Golgi transport. We have found that PKC inhibitors prevented vesicle generation, even when this was sustained by GTP gamma S and ATP levels reduced far below the K(m) of PKC. The inhibitors suppressed vesicle scission without preventing coat assembly, yet to exert their effect, they had to be added before coat assembly took place. This indicates that a target of the putative PKC is activated during the bud assembly stage of vesicle formation, but only acts during the phase of vesicle release. The behavior of the PKC target during vesicle formation resembles that of phospholipase D (PLD), a Golgi-associated enzyme that has been shown to be activated by PKC, even in the absence of the latter's phosphorylating activity. We therefore propose that during coat assembly, PKC activates a PLD that, during the incubation at 37 degrees C, promotes vesicle scission by remodeling the phospholipid bilayer and severing connections between the vesicles and the donor membrane
— id: 8519, year: 1996, vol: 135, page: 355, stat: Journal Article,

The in vitro generation of post-Golgi vesicles carrying viral envelope glycoproteins requires an ARF-like GTP-binding protein and a protein kinase C associated with the Golgi apparatus
Simon JP; Ivanov IE; Shopsin B; Hersh D; Adesnik M; Sabatini DD
1996 Jul 12;271(28):16952-16961, Journal of biological chemistry
We have developed a system that recreates in vitro the generation of post-Golgi vesicles from an isolated Golgi fraction prepared from vesicular stomatitis virus- or influenza virus-infected Madin-Darby canine kidney or HepG2 cells. In this system, vesicle generation is temperature- and ATP-dependent and requires a supply of cytosolic proteins, including an N-ethylmaleimide-sensitive factor distinct from NSF. Cytosolic proteins obtained from yeast were as effective as mammalian cytosolic proteins in supporting vesicle formation and had the same requirements. The vesicles produced (50-80 nm in diameter) are depleted of the trans Golgi marker sialyltransferase, contain the viral glycoprotein molecules with their cytoplasmic tails exposed, and do not show an easily recognizable protein coat. Vesicle generation was inhibited by brefeldin A, which indicates that it requires the activation of an Arf-like GTP-binding protein that promotes assembly of a vesicle coat. Vesicles formed in the presence of the nonhydrolyzable GTP analogue guanosine 5'-3-O-(thio)triphosphate retained a nonclathrin protein coat resembling that of COP-coated vesicles, and sedimented more rapidly in a sucrose gradient than the uncoated ones generated in its absence. This indicates that GTP hydrolysis is not required for vesicle generation but that it is for vesicle uncoating. The activity of a Golgi-associated protein kinase C (PKC) was found to be necessary for the release of post-Golgi vesicles, as indicated by the capacity of a variety of inhibitors and antibodies to PKC to suppress it, as well as by the stimulatory effect of the PKC activator 12-O-tetradecanoylphorbol-13-acetate
— id: 7048, year: 1996, vol: 271, page: 16952, stat: Journal Article,

The Brefeldin A-induced retrograde transport from the Golgi apparatus to the endoplasmic reticulum depends on calcium sequestered to intracellular stores
Ivessa NE; De Lemos-Chiarandini C; Gravotta D; Sabatini DD; Kreibich G
1995 Oct 27;270(43):25960-25967, Journal of biological chemistry
Ribophorin I is a type I transmembrane glycoprotein specific to the rough endoplasmic reticulum. We have previously shown that, when expressed in transfected HeLa cells, a carboxyl-terminally truncated form of ribophorin I that contains most of the luminal domain (RI332) is, like the native protein, retained in the endoplasmic reticulum (ER). Brefeldin A (BFA) treatment of these HeLa cells leads to O-glycosylation of RI332 by glycosyltransferases that are redistributed from the Golgi apparatus to the ER (Ivessa, N. E., De Lemos-Chiarandini, C., Tsao, Y.-S., Takatsuki, A., Adesnik, M., Sabatini, D. D., and Kreibich, G. (1992) J. Cell Biol. 117, 949-958). Using the state of glycosylation of RI332 as a measure for the BFA-induced backflow of enzymes of the Golgi apparatus to the ER, we now demonstrate that the retrograde transport is inhibited when cells are treated with various agents that affect intracellular Ca2+ concentrations, such as the dipeptide benzyloxycarbonyl (Cbz)-Gly-Phe-amide, the Ca2+ ionophore A23187, and thapsigargin, an inhibitor of the Ca(2+)-transporting ATPase of the ER. These treatments prevent the BFA-induced O-glycosylation of RI332. Immunofluorescence localization of the Golgi markers, MG-160 and galactosyltransferase, shows that when BFA is applied in the presence of Ca2+ modulating agents, the markers remain confined to the Golgi apparatus and are not redistributed to the ER, as is the case when BFA alone is used. Cbz-Gly-Phe-amide does not, however, interfere with the BFA-induced release of beta-COP from the Golgi apparatus. We conclude that the maintenance of a Ca2+ gradient between the cytoplasm and the lumen of the ER and the Golgi apparatus is required for the BFA-induced retrograde transport from the Golgi apparatus to the ER to occur
— id: 12718, year: 1995, vol: 270, page: 25960, stat: Journal Article,

Characterization of rab binding proteins that may mediate the actions of rab11 and rab8
Ren, M.; Zeng, J.; Gravotta, D.; Morimoto, T.; Rosenfled, M.; De Lemos-Chiarandini, C.; Tempsti, P.; Erdjument-Bromage, H.; Lui, M.; Adesnik, M.; Sabatini, D. D.
1995 ;6(SUPPL.):119A-119A, Molecular biology of the cell
— id: 104643, year: 1995, vol: 6, page: 119A, stat: Journal Article,

CHARACTERIZATION OF RAB BINDING-PROTEINS THAT MAY MEDIATE THE ACTIONS OF RAB11 AND RAB8
REN, M; ZENG, J; GRAVOTTA, D; MORIMOTO, T; ROSENFELD, M; DELEMOSCHIARANDINI, C; TEMPST, P; ERDJUMENTBROMAGE, H; LUI, M; ADESNIK, M; SABATINI, DD
1995 NOV ;6(23):690-690, Molecular biology of the cell
— id: 52664, year: 1995, vol: 6, page: 690, stat: Journal Article,

The biogenesis of membranes and organelles
Sabatini DD; Adesnik M
The metabolic and molecular bases of inherited disease New York : McGraw-Hill, Health Professions Division, 1995,
— id: 3525, year: 1995, vol: , page: ?, stat: Chapter,

A PKC-like activity is involved in the release of post Golgi vesicles
Simon, J.-P.; Shopsin, B.; Hersh, D.; Ivanov, I. E.; Adesnik, M.; Sabatini, D. D.
1995 ;6(SUPPL.):397A-397A, Molecular biology of the cell
— id: 104644, year: 1995, vol: 6, page: 397A, stat: Journal Article,

Actin microfilaments play a critical role in endocytosis at the apical but not the basolateral surface of polarized epithelial cells
Gottlieb TA; Ivanov IE; Adesnik M; Sabatini DD
1993 Feb;120(3):695-710, Journal of cell biology
Treatment with cytochalasin D, a drug that acts by inducing the depolymerization of the actin cytoskeleton, selectively blocked endocytosis of membrane bound and fluid phase markers from the apical surface of polarized MDCK cells without affecting the uptake from the basolateral surface. Thus, in MDCK cell transformants that express the VSV G protein, cytochalasin blocked the internalization of an anti-G mAb bound to apical G molecules, but did not reduce the uptake of antibody bound to the basolateral surface. The selective effect of cytochalasin D on apical endocytosis was also demonstrated by the failure of the drug to reduce the uptake of 125I-labeled transferrin, which occurs by receptor-mediated endocytosis, via clathrin-coated pits, almost exclusively from the basolateral surface. The actin cytoskeleton appears to play a critical role in adsorptive as well as fluid phase apical endocytic events, since treatment with cytochalasin D prevented the apical uptake of cationized ferritin, that occurs after the marker binds to the cell surface, as well as uptake of Lucifer yellow, a fluorescent soluble dye. Moreover, the drug efficiently blocked infection of the cells with influenza virus, when the viral inoculum was applied to the apical surface. On the other hand, it did not inhibit the basolateral uptake of Lucifer yellow, nor did it prevent infection with VSV from the basolateral surface, or with influenza when this virus was applied to monolayers in which the formation of tight junctions had been prevented by depletion of calcium ions. EM demonstrated that cytochalasin D leads to an increase in the number of coated pits in the apical surface where it suppresses the pinching off of coated vesicles. In addition, in drug-treated cells cationized ferritin molecules that were bound to microvilli were not cleared from the microvillar surface, as is observed in untreated cells. These findings indicate that there is a fundamental difference in the process by which endocytic vesicles are formed at the two surfaces of polarized epithelial cells and that the integrity and/or the polymerization of actin filaments are required at the apical surface. Actin filaments in microvilli may be part of a mechanochemical motor that moves membrane components along the microvillar surface towards intermicrovillar spaces, or provides the force required for converting a membrane invagination or pit into an endocytic vesicle within the cytoplasm
— id: 13277, year: 1993, vol: 120, page: 695, stat: Journal Article,

Prenylated proteins play a critical role in transport from the TGN to both cell surface domains of MDCK cells
Gravotta, D.; Mayer, A.; Adesnik, M.; Sabatini, D. D.
1993 ;4(SUPPL.):209A-209A, Molecular biology of the cell
— id: 104645, year: 1993, vol: 4, page: 209A, stat: Journal Article,

Membranes
Sabatini, David D; Louvard, Daniel; Adesnik, Milton; Higgins, CF
London : Current Biology, 1993,
— id: 1683, year: 1993, vol: , page: , stat: ,

An in vitro system for studying the biogenesis and function of Golgi-derived clathrin-coated vesicles
Simon, J.-P.; Ivanov, I. E.; De Lemos-Chiarandini, C.; Adesnik, M.; Sabatini, D. D.
1993 ;4(SUPPL.):321A-321A, Molecular biology of the cell
— id: 104646, year: 1993, vol: 4, page: 321A, stat: Journal Article,

CELL-FREE TRANSPORT OF VIRAL MEMBRANE-GLYCOPROTEINS FROM THE GOLGI-APPARATUS TO THE PLASMA-MEMBRANE OF POLARIZED CELLS
SIMON, JP; MAYER, A; GRAVOTTA, D; IVANOV, I; ADESNIK, M; SABATINI, DD
1993 JAN 26 ;36(1):263-263, Journal of cellular biochemistry
— id: 54369, year: 1993, vol: 36, page: 263, stat: Journal Article,

Genomic organization of the rat ribophorin II gene: Common cis-regulatory elements are found in the 5' flanking regions of the rat ribophorin I and ribophorin II genes
Zhou, Z.; Prakash, K.; Rajasekaran, A. K.; Adesnik, M.; Sabatini, D. D.; Kreibich, G.
1993 ;4(SUPPL.):423A-423A, Molecular biology of the cell
— id: 104647, year: 1993, vol: 4, page: 423A, stat: Journal Article,

MUTATION OF THE TYROSINE-CONTAINING ENDOCYTIC SIGNAL IN THE VSV G-PROTEIN IMPAIRS BASOLATERAL BUT NOT APICAL ENDOCYTOSIS IN MDCK CELLS
GOTTLIEB, T; KRUPPA, J; KRUPPA, A; ADESNIK, M; SABATINI, D
1992 SEP ;3(4):A303-A303, Molecular biology of the cell
— id: 51868, year: 1992, vol: 3, page: A303, stat: Journal Article,

O-glycosylation of intact and truncated ribophorins in brefeldin A-treated cells: newly synthesized intact ribophorins are only transiently accessible to the relocated glycosyltransferases
Ivessa NE; De Lemos-Chiarandini C; Tsao YS; Takatsuki A; Adesnik M; Sabatini DD; Kreibich G
1992 Jun;117(5):949-958, Journal of cell biology
Ribophorins I and II are type I transmembrane glycoproteins of the ER that are segregated to the rough domains of this organelle. Both ribophorins appear to be part of the translocation apparatus for nascent polypeptides that is associated with membrane-bound ribosomes and participate in the formation of a proteinaceous network within the ER membrane that also includes other components of the translocation apparatus. The ribophorins are both highly stable proteins that lack O-linked sugars but each contains one high mannose N-linked oligosaccharide that remains endo H sensitive throughout their lifetimes. We have previously shown (Tsao, Y. S., N. E. Ivessa, M. Adesnik, D. D. Sabatini, and G. Kreibich. 1992. J. Cell Biol. 116:57-67) that a COOH-terminally truncated variant of ribophorin I that contains only the first 332 amino acids of the luminal domain (RI332), when synthesized in permanent transformants of HeLa cells, undergoes a rapid degradation with biphasic kinetics in the ER itself and in a second, as yet unidentified nonlysosomal pre-Golgi compartment. We now show that in cells treated with brefeldin A (BFA) RI332 molecules undergo rapid O-glycosylation in a multistep process that involves the sequential addition of N-acetylgalactosamine, galactose, and terminal sialic acid residues. Addition of O-linked sugars affected all newly synthesized RI332 molecules and was completed soon after synthesis with a half time of about 10 min. In the same cells, intact ribophorins I and II also underwent O-linked glycosylation in the presence of BFA, but these molecules were modified only during a short time period immediately after their synthesis was completed, and the modification affected only a fraction of the newly synthesized polypeptides. More important, these molecules synthesized before the addition of BFA were not modified by O-glycosylation. The same is true for ribophorin I when overexpressed in HeLa cells although it is significantly less stable than the native polypeptide in control cells. We, therefore, conclude that soon after their synthesis, ribophorins lose their susceptibility to the relocated Golgi enzymes that effect the O-glycosylation, most likely as a consequence of a conformational change in the ribophorins that occurs during their maturation, although it cannot be excluded that rapid integration of these molecules into a supramolecular complex in the ER membrane leads to their inaccessibility to these enzymes
— id: 13579, year: 1992, vol: 117, page: 949, stat: Journal Article,

Sticking together for a difficult passage
Kreibich G; Sabatini DD
1992 Feb;2(2):90-92, Current biology. CB
— id: 44806, year: 1992, vol: 2, page: 90, stat: Journal Article,

Membranes
Louvard D; Adesnik M; Sabatini DD
1992 ;4:569-572, Current opinion in cell biology
— id: 55894, year: 1992, vol: 4, page: 569, stat: Journal Article,

CELL-FREE RECONSTITUTION OF THE POLARIZED TRANSPORT OF A VIRAL GLYCOPROTEIN FROM THE TGN TO THE BASOLATERAL PLASMA-MEMBRANE OF MDCK CELLS
MAYER, A; IVANOV, I; ADESNIK, M; SABATINI, D
1992 SEP ;3(4):A307-A307, Molecular biology of the cell
— id: 51869, year: 1992, vol: 3, page: A307, stat: Journal Article,

ROLE OF CHARGED AMINO-ACIDS WITHIN THE SEGMENTS FLANKING THE HYDROPHOBIC CORE OF A SIGNAL ANCHOR SEQUENCE IN DETERMINING THE TRANSMEMBRANE DISPOSITION OF A PROTEIN
MONIER, S; SABATINI, D; ADESNIK, M
1992 SEP ;3(4):A125-A125, Molecular biology of the cell
— id: 51862, year: 1992, vol: 3, page: A125, stat: Journal Article,

INVITRO FORMATION OF POST GOLGI VESICLES CARRYING VIRAL ENVELOPE GLYCOPROTEINS
SIMON, JP; IVANOV, I; RINDLER, M; ADESNIK, M; SABATINI, DD
1992 SEP ;3(4):A308-A308, Molecular biology of the cell
— id: 51870, year: 1992, vol: 3, page: A308, stat: Journal Article,

Carboxy terminally truncated forms of ribophorin I are degraded in pre-Golgi compartments by a calcium-dependent process
Tsao YS; Ivessa NE; Adesnik M; Sabatini DD; Kreibich G
1992 Jan;116(1):57-67, Journal of cell biology
Two COOH terminally truncated variants of ribophorin I (RI), a type I transmembrane glycoprotein of 583 amino acids that is segregated to the rough portions of the ER and is associated with the protein-translocating apparatus of this organelle, were expressed in permanent HeLa cell transformants. Both variants, one membrane anchored but lacking part of the cytoplasmic domain (RL467) and the other consisting of the luminal 332 NH2-terminal amino acids (RI332), were retained intracellularly but, in contrast to the endogenous long lived, full length ribophorin I (t 1/2 = 25 h), were rapidly degraded (t 1/2 less than 50 min) by a nonlysosomal mechanism. The absence of a measurable lag phase in the degradation of both truncated ribophorins indicates that their turnover begins in the ER itself. The degradation of RI467 was monophasic (t 1/2 = 50 min) but the rate of degradation of RI332 molecules increased about threefold approximately 50 min after their synthesis. Several pieces of evidence suggest that the increase in degradative rate is the consequence of the transport of RI332 molecules that are not degraded during the first phase to a second degradative compartment. Thus, when added immediately after labeling, ionophores that inhibit vesicular flow out of the ER, such as carbonyl cyanide m-chlorophenylhydrazone (CCCP) and monensin, suppressed the second phase of degradation of RI332. On the other hand, when CCCP was added after the second phase of degradation of RI332 was initiated, the degradation was unaffected. Moreover, in cells treated with brefeldin A the degradation of RI332 became monophasic, and took place with a half-life intermediate between those of the two normal phases. These results point to the existence of two subcellular compartments where abnormal ER proteins can be degraded. One is the ER itself and the second is a non-lysosomal pre-Golgi compartment to which ER proteins are transported by vesicular flow. A survey of the effects of a variety of other ionophores and protease inhibitors on the turnover of RI332 revealed that metalloproteases are involved in both phases of the turnover and that the maintenance of a high Ca2+ concentration is necessary for the degradation of the luminally truncated ribophorin
— id: 13723, year: 1992, vol: 116, page: 57, stat: Journal Article,

Expression, localization, and function of an N-terminal half fragment of the rat Na,K-ATPase beta-subunit in HeLa cells
Omori K; Omori K; Morimoto T; Takada T; Akayama M; Yoshimori T; Sabatini DD; Tashiro Y
1991 Feb;109(2):267-275, Journal of biochemistry (Tokyo)
The N-terminal half of the beta-subunit of rat brain Na,K-ATPase was expressed in HeLa cells transfected with the plasmid pSV2TKneo beta N containing the truncated beta-subunit cDNA to study the assembly and transport of alpha-beta complex. Immunoprecipitation from extracts of metabolically labeled transformed cells demonstrated that the truncated beta-subunit polypeptide (beta N) was neither transported to the plasma membrane nor assembled into an alpha-beta complex with the endogenous alpha-subunit. Cell fractionation experiments showed that the beta N truncated subunit remained unassembled within rough microsomes, suggesting that it never exited from the endoplasmic reticulum (ER). The assembly of the endogenous alpha-and beta-subunits in the beta N-expressing cells was significantly inhibited compared with control cells or with the transformants that did not express the beta N. These results suggest that the N-terminal portion of the beta-subunit interferes with the normal assembly of the endogenous complex which normally takes place in the ER
— id: 58806, year: 1991, vol: 109, page: 267, stat: Journal Article,

Rat ribophorin II: molecular cloning and chromosomal localization of a highly conserved transmembrane glycoprotein of the rough endoplasmic reticulum
Pirozzi G; Zhou ZM; D'Eustachio P; Sabatini DD; Kreibich G
1991 May 15;176(3):1482-1486, Biochemical & biophysical research communications
We report here the complete nucleotide sequence of rat ribophorin II. The predicted amino acid sequence is highly homologous to the corresponding human protein and consists of 631 amino acid residues, including a 22 amino acid N-terminal cleavable signal sequence, and a single 23 amino acid putative transmembrane domain. Northern blot analysis reveals a single -2.4 kb message expressed in a number of rat cell lines and in adult liver. The gene was mapped to mouse chromosome 2, close to the Src proto-oncogene
— id: 14023, year: 1991, vol: 176, page: 1482, stat: Journal Article,

Membranes
Sabatini DD; Louvard D; Adesnik M
1991 Aug;3(4):575-579, Current opinion in cell biology
— id: 55807, year: 1991, vol: 3, page: 575, stat: Journal Article,

Structure and chromosomal location of the rat ribophorin I gene
Behal A; Prakash K; D'Eustachio P; Adesnik M; Sabatini DD; Kreibich G
1990 May 15;265(14):8252-8258, Journal of biological chemistry
Ribophorin I is a type I transmembrane glycoprotein characteristic of the rough portions of the endoplasmic reticulum where it is thought to play a role in the cotranslational insertion of nascent polypeptides. A rat ribophorin I cDNA was used to isolate four overlapping genomic clones from a rat EMBL3 genomic library. Restriction mapping, Southern blotting, and DNA sequencing showed that these clones, spanning approximately 21 kilobases of chromosomal DNA, include the entire ribophorin I gene, as well as 15 kilobases (kb) of upstream sequences. Southern blotting analysis of DNA from a panel of mouse-Chinese hamster cell hybrids demonstrated that the ribophorin I gene is located on mouse chromosome six. The ribophorin I gene contains 10 exons, seven of which encode the luminal domain of the polypeptide. Exon 8 encodes the trans-membrane domain and small portions of the flanking luminal and cytoplasmic domains. Exons 9 and 10 encode the remainder of the cytoplasmic domain, and the latter includes the 3'-untranslated portion of the mRNA. Six closely spaced transcription start sites located 3 to 24 base pairs upstream from the initiation codon were identified by primer extension analysis and S1 mapping. The sequence of a 1.3-kb region upstream of the cap sites was determined and found to contain three GC-rich potential Sp1-binding sites beginning at -14, -24, and -91 base pairs (bp), two octamer-like sequences at -233 and -1248 bp, and a CAAT-like box at -41 bp. The possible roles of these elements in regulating expression of the ribophorin gene in all cells and in differentiated cell types characterized by a well developed rough endoplasmic reticulum is discussed
— id: 17245, year: 1990, vol: 265, page: 8252, stat: Journal Article,

A PROCEDURE FOR THE SELECTIVE PERMEABILIZATION OF THE APICAL OR BASOLATERAL PLASMA MEMBRANE DOMAINS OF EPITHELIAL CELLS THAT ALLOWS THE STUDY OF MEMBRANE PROTEIN TRANSPORT
GRAVOTTA D; ADESNIK M; SABATINI D D
1990 ;111(5 PART 2):325A-325A, Journal of cell biology
— id: 104649, year: 1990, vol: 111, page: 325A, stat: Journal Article,

TRANSPORT OF INFLUENZA HA FROM THE TGN TO APICAL SURFACE OF MDCK CELLS TAKES PLACE IN TWO STEPS THAT ARE DIFFERENTIALLY AFFECTED BY GTP-GAMMA-S
GRAVOTTA D; ADESNIK M; SABATINI D D
1990 ;111(5 PART 2):326A-326A, Journal of cell biology
— id: 104650, year: 1990, vol: 111, page: 326A, stat: Journal Article,

Transport of influenza HA from the trans-Golgi network to the apical surface of MDCK cells permeabilized in their basolateral plasma membranes: energy dependence and involvement of GTP-binding proteins
Gravotta D; Adesnik M; Sabatini DD
1990 Dec;111(6 Pt 2):2893-2908, Journal of cell biology
A procedure employing streptolysin O to effect the selective permeabilization of either the apical or basolateral plasma membrane domains of MDCK cell monolayers grown on a filter support was developed which permeabilizes the entire monolayer, leaves the opposite cell surface domain intact, and does not abolish the integrity of the tight junctions. This procedure renders the cell interior accessible to exogenous macromolecules and impermeant reagents, permitting the examination of their effects on membrane protein transport to the intact surface. The last stages of the transport of the influenza virus hemagglutinin (HA) to the apical surface were studied in pulse-labeled, virus-infected MDCK cells that were incubated at 19.5 degrees C for 90 min to accumulate newly synthesized HA in the trans-Golgi network (TGN), before raising the temperature to 35 degrees C to allow synchronized transport to the plasma membrane. In cells permeabilized immediately after the cold block, 50% of the intracellular HA molecules were subsequently delivered to the apical surface. This transport was dependent on the presence of an exogenous ATP supply and was markedly inhibited by the addition of GTP-gamma-S at the time of permeabilization. On the other hand, the GTP analogue had no effect when it was added to cells that, after the cold block, were incubated for 15 min at 35 degrees C before permeabilization, even though at this time most HA molecules were still intracellular and their appearance at the cell surface was largely dependent on exogenous ATP. These findings indicate that GTP-binding proteins are involved in the constitutive process that effects vesicular transport from the TGN to the plasma membrane and that they are charged early in this process. Transport of HA to the cell surface could be made dependent on the addition of exogenous cytosol when, after permeabilization, cells were washed to remove endogenous cytosolic components. This opens the way towards the identification of cell components that mediate the sorting of apical and basolateral membrane components in the TGN and their polarized delivery to the cell surface
— id: 14265, year: 1990, vol: 111, page: 2893, stat: Journal Article,

Antiribophorin antibodies inhibit the targeting to the ER membrane of ribosomes containing nascent secretory polypeptides
Yu YH; Sabatini DD; Kreibich G
1990 Oct;111(4):1335-1342, Journal of cell biology
Polyclonal antibodies directed against ribophorins I and II, two membrane glycoproteins characteristic of the rough endoplasmic reticulum, inhibit the cotranslational translocation of a secretory protein growth hormone into the lumen of dog pancreas or rat liver microsomes. As expected, site-specific antibodies to epitopes located within the cytoplasmic domain of ribophorin I, but not antibodies to epitopes in the luminal domain of this protein, were effective in inhibiting translocation. Since monovalent Fab fragments were as inhibitory as intact IgG molecules, ribophorins must be closely associated with the translocation site and, therefore, are likely to function at some stage in the translocation process. In all cases, the antibodies that inhibited translocation also caused a significant reduction in total protein synthesis and treatments that neutralized their capacity to inhibit translocation also prevented their inhibitory effect on protein synthesis. This would be expected if the antibodies blocked the membrane-mediated relief of the SRP-induced arrest of polypeptide elongation. The antibodies were effective only when added before translocation was allowed to begin. In this case, they prevented the targeting of active ribosomes containing mRNA and nascent chains to the ER membrane. Thus, ribophorins must either directly participate in targeting or be so close to the targeting site that the antibodies sterically blocked this early phase of the translocation process
— id: 18415, year: 1990, vol: 111, page: 1335, stat: Journal Article,

A sorting signal for the basolateral delivery of the vesicular stomatitis virus (VSV) G protein lies in its luminal domain: analysis of the targeting of VSV G-influenza hemagglutinin chimeras
Compton T; Ivanov IE; Gottlieb T; Rindler M; Adesnik M; Sabatini DD
1989 Jun;86(11):4112-4116, Proceedings of the National Academy of Sciences of the United States of America
When synthesized in polarized epithelial cells, the envelope glycoproteins hemagglutinin of influenza and G of vesicular stomatitis virus are targeted to the apical and basolateral plasma membranes, respectively. To determine which portions of these transmembrane proteins contain information necessary for their sorting, the behavior of two different G-hemagglutinin chimeric polypeptides, consisting of all or nearly all the luminal portion of the vesicular stomatitis virus G protein linked to C-terminal segments of influenza hemagglutinin that included its transmembrane and cytoplasmic domains, was studied in MDCK cells transformed with the corresponding cDNAs. Both chimeras were transported from the endoplasmic reticulum to the Golgi apparatus and from there to the cell surface with the same rapid kinetics as the intact G protein. By using a cell surface immunoprecipitation assay with monolayers cultured on permeable filters that allows the recovery of labeled protein molecules present in each cell surface domain, it was found that both chimeric proteins as well as the intact G protein were delivered almost exclusively to the basolateral surface. This polarized distribution of the polypeptides did not change during a subsequent 90-min chase period, although during this time a large fraction of the glycoprotein molecules underwent degradation. In addition, a small fraction of the cell surface-associated glycoprotein molecules shed their ectoplasmic segments into the basolateral compartment, apparently as a result of a proteolytic cleavage. Immunofluorescence on transverse frozen sections and immunoelectron microscopy revealed a prominent accumulation of the chimeric polypeptides in the lateral cell membranes, with lesser amounts on the basal and apical surfaces. These results indicate that information specifying the basolateral transport of the G glycoprotein is located within the first 426 N-terminal amino acids of its ectoplasmic portion
— id: 10609, year: 1989, vol: 86, page: 4112, stat: Journal Article,

Endolyn-78, a membrane glycoprotein present in morphologically diverse components of the endosomal and lysosomal compartments: implications for lysosome biogenesis
Croze E; Ivanov IE; Kreibich G; Adesnik M; Sabatini DD; Rosenfeld MG
1989 May;108(5):1597-1613, Journal of cell biology
A monoclonal antibody (2C5) raised against rat liver lysosomal membranes was used to identify a 78-kD glycoprotein that is present in the membranes of both endosomes and lysosomes and, therefore, is designated endolyn-78. In cultures of rat hepatoma (Fu5C8) and kidney cells (NRK), this glycoprotein could not be labeled with [35S]methionine or with [32P]inorganic phosphate but was easily labeled with [35S]cysteine and [3H]mannose. Pulse-chase experiments and determinations of endoglycosidase H (endo H) sensitivity showed that endolyn-78 is derived from a precursor of Mr 58-62 kD that is processed to the mature form with a t1/2 of 15-30 min. The protein has a 22-kD polypeptide backbone that is detected after a brief pulse in tunicamycin-treated cells. During a chase in the presence of the drug, this is converted into an O-glycosylated product of 46 kD that despite the absence of N-linked oligosaccharides is effectively transferred to lysosomes. This demonstrates that the delivery of endolyn-78 to this organelle is not mediated by the mannose-6-phosphate receptor (MPR). Immunocytochemical experiments showed that endolyn-78 is present in the limiting membranes and the interior membranous structures of morphologically identifiable secondary lysosomes that contain the lysosomal hydrolase beta-glucuronidase, lack the MPR, and could not be labeled with alpha-2-macroglobulin at 18.5 degrees C, a temperature which prevents appearance of endocytosed markers in lysosomes. Endolyn-78 was present at low levels in the plasma membrane and in peripheral tubular endosomes, but was prominent in morphologically diverse components of the endosomal compartment (vacuolar endosomes and various types of multivesicular bodies) which acquired alpha-2-macroglobulin at 18.5 degrees C, and frequently contained substantial levels of the MPR and variable levels of beta-glucuronidase. On the other hand, the MPR was very rarely found in endolyn-containing structures that were not labeled with alpha-2-macroglobulin at the low temperature. Thus, the process of lysosomal maturation appears to involve the progressive delivery of lysosomal enzymes to various types of endosomes that may have already received some of the lysosomal membrane proteins. Although endolyn-78 would be one of the proteins added early to endosomes, other lysosomal membrane proteins may be added only to multivesicular endosomes that represent very advanced stages of maturation
— id: 10656, year: 1989, vol: 108, page: 1597, stat: Journal Article,

Reconstitution of translocation-competent membrane vesicles from detergent-solubilized dog pancreas rough microsomes
Yu YH; Zhang YY; Sabatini DD; Kreibich G
1989 Dec;86(24):9931-9935, Proceedings of the National Academy of Sciences of the United States of America
Dog pancreas rough microsomes were solubilized in 1% octyl beta-glucoside, and membrane vesicles were reconstituted by slow 30-fold dilution with a buffer of low ionic strength. Asymmetric assembly of the membranes occurred during reconstitution since the vesicles formed contained ribosomes bound only to the vesicular outer surfaces. The reconstituted vesicles were similar in protein composition to native rough microsomes, although these vesicles were largely devoid of luminal-content proteins. These reconstituted vesicles could translocate and process nascent secretory (human placental lactogen) and membrane proteins (influenza hemagglutinin and rat liver ribophorin I) synthesized in cell-free translation systems programmed with the corresponding mRNAs. Signal cleavage and N-glycosylation only occurred when the reconstituted membranes were present during translation, providing evidence that the translocation apparatus was asymmetrically assembled into the reconstituted membranes. When a supernatant lacking ribosomes and particles greater than 50S from centrifuging the detergent-solubilized microsomes at high speed was used for reconstitution, smooth-surfaced membrane vesicles were obtained that, except for the absence of ribosomal proteins, were similar in protein composition to that of the reconstituted vesicles from total solubilized rough microsomes. The reconstituted smooth-surfaced vesicles, however, were totally inactive in cotranslational processing and translocation of nascent polypeptides. These findings suggest that ribosomes and/or large macromolecular complexes, not dissociated under our solubilization conditions, are essential for in vitro assembly of a functional translocation apparatus
— id: 10409, year: 1989, vol: 86, page: 9931, stat: Journal Article,

STRUCTURE OF THE RAT RIBOPHORIN I GENE
BEHAL A; PRAKASH K; ADESNIK M; SABATINI D D; KREIBICH G
1988 ;107(6 PART 3):762A-762A, Journal of cell biology
— id: 104651, year: 1988, vol: 107, page: 762A, stat: Journal Article,

CLONING OF A COMPLEMENTARY DNA ENCODING A RAT LIVER POLYPEPTIDE BEARING COMMON ANTIGENIC DETERMINANTS TO A LYSOSOMAL-ENDOSOMAL MEMBRANE PROTEIN
HYMAN C; MORIMOTO T; ADESNIK M; SABATINI D D; ROSENFELD M
1988 ;107(6 PART 3):343A-343A, Journal of cell biology
— id: 104653, year: 1988, vol: 107, page: 343A, stat: Journal Article,

Signals for the incorporation and orientation of cytochrome P450 in the endoplasmic reticulum membrane
Monier S; Van Luc P; Kreibich G; Sabatini DD; Adesnik M
1988 Aug;107(2):457-470, Journal of cell biology
Cytochrome P450b is an integral membrane protein of the rat hepatocyte endoplasmic reticulum (ER) which is cotranslationally inserted into the membrane but remains largely exposed on its cytoplasmic surface. The extreme hydrophobicity of the amino-terminal portion of P450b suggests that it not only serves to initiate the cotranslational insertion of the nascent polypeptide but that it also halts translocation of downstream portions into the lumen of the ER and anchors the mature protein in the membrane. In an in vitro system, we studied the cotranslational insertion into ER membranes of the normal P450b polypeptide and of various deletion variants and chimeric proteins that contain portion of P450b linked to segments of pregrowth hormone or bovine opsin. The results directly established that the amino-terminal 20 residues of P450b function as a combined insertion-halt-transfer signal. Evidence was also obtained that suggests that during the early stages of insertion, this signal enters the membrane in a loop configuration since, when the amino-terminal hydrophobic segment was placed immediately before a signal peptide cleavage site, cleavage by the luminally located signal peptidase took place. After entering the membrane, the P450b signal, however, appeared to be capable of reorienting within the membrane since a bovine opsin peptide segment linked to the amino terminus of the signal became translocated into the microsomal lumen. It was also found that, in addition to the amino-terminal combined insertion-halt-transfer signal, only one other segment within the P450b polypeptide, located between residues 167 and 185, could serve as a halt-transfer signal and membrane-anchoring domain. This segment was shown to prevent translocation of downstream sequences when the amino-terminal combined signal was replaced by the conventional cleavable insertion signal of a secretory protein
— id: 11017, year: 1988, vol: 107, page: 457, stat: Journal Article,

BIOSYNTHESIS OF IL-1 ALPHA IN CULTURED MACROPHAGES AND TRANSFECTED CELLS
MOORE B; ZHANG Y; ADESNIK M; SABATINI D D
1988 ;107(6 PART 3):699A-699A, Journal of cell biology
— id: 104654, year: 1988, vol: 107, page: 699A, stat: Journal Article,

Characterization and expression of a cDNA clone for the beta subunit of rat brain Na+,K+-ATPase
Omori K; Omori K; Flanagan M; Desai VA; Nabi N; Sugita Y; Haldar D; Sherman JM; Sabatini DD; Morimoto T
1988 ;268B:127-134, Progress in clinical & biological research
— id: 11281, year: 1988, vol: 268B, page: 127, stat: Journal Article,

[Use of cultured, virus-infected cells to study the biogenesis of polarity of epithelial cells]
Sabatini DD; Ivanov IE; Gottlieb TA; Compton T; Gonzalez A; Beaudry G; Rindler MJ
1988 ;49(4-5):270-286, Annales d'endocrinologie
The major characteristic of the eucaryote cell is the presence of specialized organelles in which macromolecular components responsible for various subcellular functions are segregated. The membranes of these organelles serve not only as divisions between the various cytoplasmic compartments, but also provide scaffolding within which the macromolecular complexes of the organelle assemble and become functionally integrated. It is obvious that because of the degree of complexity resulting from the existence of numerous compartments and membrane systems, the development of a genetic programme in a eucaryote cell requires not only the transcription of specific genes and translation in the cytoplasma of the resultant messenger RNA, but also the activity of mechanisms which ensure that each polypeptide reaches the site of its function, which may be in the cytosol, in a membrane, or in the luminal cavity of an organelle. In the special case of membrane proteins, such mechanisms must result not only in the specific distribution of polypeptides newly synthesized in the various types of cell membrane, but also the arrangement of them required in the lipid bi-layer necessary for their normal function
— id: 11283, year: 1988, vol: 49, page: 270, stat: Journal Article,

RAPID INTRACELLULAR DEGRADATION OF A TRUNCATED FORM OF RIBOPHORIN I
TSAO Y-S; IVESSA N E; ADESNIK M; SABATINI D D; KREIBICH G
1988 ;107(6 PART 3):764-764, Journal of cell biology
— id: 104655, year: 1988, vol: 107, page: 764, stat: Journal Article,

Molecular cloning of a 2',3'-cyclic nucleotide 3'-phosphodiesterase: mRNAs with different 5' ends encode the same set of proteins in nervous and lymphoid tissues
Bernier L; Alvarez F; Norgard EM; Raible DW; Mentaberry A; Schembri JG; Sabatini DD; Colman DR
1987 Sep;7(9):2703-2710, Journal of neuroscience
Antibodies raised to a mixture of the 46 and 48 kDa rat CNS 2',3'-cyclic nucleotide 3-phosphodiesterases (CNPs) recognized apparently identical proteins in peripheral nervous system (PNS), thymus, and circulating blood lymphocytes. These antibodies were used to identify, in a rat brain phage lambda gt11 expression library, cDNA clones encoding beta-galactosidase-CNP fusion proteins, some of which showed CNP activity. In RNA blots, the subcloned CNP cDNA inserts hybridized to mRNAs of approximately 2400 and approximately 2800 nucleotides (nts), and to a approximately 2500 nt mRNA from thymus. Several nonexpressing CNP cDNAs were identified by plaque hybridization, and the mRNA transcribed in vitro from one of these cDNAs (pCNP7) encoded a complete 46 kDa CNP polypeptide. Examination of the deduced amino acid sequence revealed an apparent homology to cAMP binding sites in several other proteins. A 373 bp segment from the 5' end of this pCNP7 hybridized only to the 2800 nt nervous system mRNAs, thus revealing that not all CNP mRNAs share the same 5'-ends. Genomic DNA blots probed with CNP cDNAs suggest that there is a single gene which can be alternatively spliced to produce the various mRNA transcripts in the nervous and lymphoid tissues
— id: 58807, year: 1987, vol: 7, page: 2703, stat: Journal Article,

Determination of the membrane topology of the phenobarbital-inducible rat liver cytochrome P-450 isoenzyme PB-4 using site-specific antibodies
De Lemos-Chiarandini C; Frey AB; Sabatini DD; Kreibich G
1987 Feb;104(2):209-219, Journal of cell biology
Fifteen peptides, ranging in length from 6 to 31 amino acids and corresponding in sequence to portions of the major phenobarbital-inducible form of rat liver cytochrome P-450 (P-450 PB-4), were previously synthesized chemically and used to prepare site-specific rabbit antibodies (Frey, A. B., D.J. Waxman, and G. Kreibich, 1985, J. Biol. Chem., 260:15253-15265). The antipeptide antibodies were affinity purified using Sepharose resins derivatized with the respective peptides and 14 preparations were obtained that in an ELISA assay showed affinities to immobilized P-450 judged to be adequate for binding studies on intact rat liver microsomes. The binding of these antibodies to rough microsomes from the livers of phenobarbital treated rats was assessed using 125I-labeled IgG and by immunoelectron microscopy employing protein A-gold as a marker. It was found that many of the antibodies bound to the cytoplasmic surface of the membrane but none bound to the luminal face of ruptured or inverted microsomal vesicles or to contaminating membranes of other organelles present in the preparations. These observations eliminate previously proposed models for the transmembrane disposition of P-450 that postulate the existence of multiple transmembrane domains and the exposure of several polar segments of the polypeptide on the luminal side of the membrane. The fact that an antibody raised to the first 31 residues of P-450 bound well to the purified P-450 but very poorly to rough microsomes, whereas an antibody to a peptide comprising residues 24-38 showed relatively strong binding to intact microsomes, is consistent with the proposal that the amino terminal segment of P-450 extending approximately to residue 20 is embedded in the phospholipid bilayer and the immediately following segment is exposed on the cytoplasmic surface of the membrane. All these results favor a model in which the cytochrome P-450 molecule is largely exposed on the cytoplasmic surface of the endoplasmic reticulum membrane to which it is anchored by its short amino terminal hydrophobic segment
— id: 18421, year: 1987, vol: 104, page: 209, stat: Journal Article,

The influenza hemagglutinin insertion signal is not cleaved and does not halt translocation when presented to the endoplasmic reticulum membrane as part of a translocating polypeptide
Finidori J; Rizzolo L; Gonzalez A; Kreibich G; Adesnik M; Sabatini DD
1987 Jun;104(6):1705-1714, Journal of cell biology
The co-translational insertion of polypeptides into endoplasmic reticulum membranes may be initiated by cleavable amino-terminal insertion signals, as well as by permanent insertion signals located at the amino-terminus or in the interior of a polypeptide. To determine whether the location of an insertion signal within a polypeptide affects its function, possibly by affecting its capacity to achieve a loop disposition during its insertion into the membrane, we have investigated the functional properties of relocated insertion signals within chimeric polypeptides. An artificial gene encoding a polypeptide (THA-HA), consisting of the luminal domain of the influenza hemagglutinin preceded by its amino-terminal signal sequence and linked at its carboxy-terminus to an intact prehemagglutinin polypeptide, was constructed and expressed in in vitro translation systems containing microsomal membranes. As expected, the amino-terminal signal initiated co-translational insertion of the hybrid polypeptide into the membranes. The second, identical, interiorized signal, however, was not recognized by the signal peptidase and was translocated across the membrane. The failure of the interiorized signal to be cleaved may be attributed to the fact that it enters the membrane as part of a translocating polypeptide and therefore cannot achieve the loop configuration that is thought to be adopted by signals that initiate insertion. The finding that the interiorized signal did not halt translocation of downstream sequences, even though it contains a hydrophobic region and must enter the membrane in the same configuration as natural stop-transfer signals, indicates that the HA insertion signal lacks essential elements of halt transfer signals that makes the latter effective membrane-anchoring domains. When the amino-terminal insertion signal of the THA-HA chimera was deleted, the interior signal was incapable of mediating insertion, probably because of steric hindrance by the folded preceding portions of the chimera. Several chimeras were constructed in which the interiorized signal was preceded by polypeptide segments of various lengths. A signal preceded by a segment of 111 amino acids was also incapable of initiating insertion, but insertion took place normally when the segment preceding the signal was only 11-amino acids long.(ABSTRACT TRUNCATED AT 400 WORDS)
— id: 18418, year: 1987, vol: 104, page: 1705, stat: Journal Article,

Nonpolarized secretion of truncated forms of the influenza hemagglutinin and the vesicular stomatitus virus G protein from MDCK cells
Gonzalez A; Rizzolo L; Rindler M; Adesnik M; Sabatini DD; Gottlieb T
1987 Jun;84(11):3738-3742, Proceedings of the National Academy of Sciences of the United States of America
The demonstration that the envelope glycoproteins G of vesicular stomatitus virus and hemagglutinin of influenza virus synthesized in polarized epithelial cells transfected with the corresponding genes are effectively segregated to the basolateral or apical plasma membrane domains, respectively, implies that the information determining this segregation resides within the structures of the proteins themselves. To localize the sorting information within these proteins, the polarity of secretion of truncated hemagglutinin and G glycoproteins secreted from confluent monolayers of MDCK cells transformed with vectors containing the corresponding truncated cDNAs was examined. It was found that, even though the transformed cells continued to secrete a major endogenous glycoprotein exclusively from the apical surface, the modified viral glycoproteins were secreted in a nonpolarized fashion from both sides of the monolayers. These observations suggest that important information for the sorting of the viral glycoprotein is contained within their membrane anchoring or cytoplasmic segments or that, if sorting signals are luminally located, these signals must be present in a conformation that is not attainable when the polypeptides are not attached to the membrane
— id: 55809, year: 1987, vol: 84, page: 3738, stat: Journal Article,

Sorting Of Plasma Membrane And Secretory Proteins In Cultured Polarized Epithelial Cells
Gottlieb TA; Gonzalez A; Beaudry G; Rindler MJ; Adesnik M; Sabatini DD
Molecular mechanisms in the regulation of cell behavior New York : Liss, 1987,
— id: 5236, year: 1987, vol: , page: 187, stat: Chapter,

Isolation and characterization of cDNA clones for rat ribophorin I: complete coding sequence and in vitro synthesis and insertion of the encoded product into endoplasmic reticulum membranes
Harnik-Ort V; Prakash K; Marcantonio E; Colman DR; Rosenfeld MG; Adesnik M; Sabatini DD; Kreibich G
1987 Apr;104(4):855-863, Journal of cell biology
Ribophorins I and II are two transmembrane glycoproteins that are characteristic of the rough endoplasmic reticulum and are thought to be part of the apparatus that affects the co-translational translocation of polypeptides synthesized on membrane-bound polysomes. A ribophorin I cDNA clone containing a 0.6-kb insert was isolated from a rat liver lambda gtll cDNA library by immunoscreening with specific antibodies. This cDNA was used to isolate a clone (2.3 kb) from a rat brain lambda gtll cDNA library that contains the entire ribophorin I coding sequence. SP6 RNA transcripts of the insert in this clone directed the in vitro synthesis of a polypeptide of the expected size that was immunoprecipitated with anti-ribophorin I antibodies. When synthesized in the presence of microsomes, this polypeptide, like the translation product of the natural ribophorin I mRNA, underwent membrane insertion, signal cleavage, and co-translational glycosylation. The complete amino acid sequence of the polypeptide encoded in the cDNA insert was derived from the nucleotide sequence and found to contain a segment that corresponds to a partial amino terminal sequence of ribophorin I that was obtained by Edman degradation. This confirmed the identity of the cDNA clone and established that ribophorin I contains 583 amino acids and is synthesized with a cleavable amino terminal insertion signal of 22 residues. Analysis of the amino acid sequence of ribophorin I suggested that the polypeptide has a simple transmembrane disposition with a rather hydrophilic carboxy terminal segment of 150 amino acids exposed on the cytoplasmic face of the membrane, and a luminal domain of 414 amino acids containing three potential N-glycosylation sites. Hybridization measurements using the cloned cDNA as a probe showed that ribophorin I mRNA levels increase fourfold 15 h after partial hepatectomy, in confirmation of measurements made by in vitro translation of liver mRNA. Southern blot analysis of rat genomic DNA suggests that there is a single copy of the ribophorin I gene in the haploid rat genome
— id: 18420, year: 1987, vol: 104, page: 855, stat: Journal Article,

Microtubule-acting drugs lead to the nonpolarized delivery of the influenza hemagglutinin to the cell surface of polarized Madin-Darby canine kidney cells
Rindler MJ; Ivanov IE; Sabatini DD
1987 Feb;104(2):231-241, Journal of cell biology
The synchronized directed transfer of the envelope glycoproteins of the influenza and vesicular stomatitis viruses from the Golgi apparatus to the apical and basolateral surfaces, respectively, of polarized Madin-Darby canine kidney (MDCK) cells can be achieved using temperature-sensitive mutant viruses and appropriate temperature shift protocols (Rindler, M. J., I. E. Ivanov, H. Plesken, and D. D. Sabatini, 1985, J. Cell Biol., 100:136-151). The microtubule-depolymerizing agents colchicine and nocodazole, as well as the microtubule assembly-promoting drug taxol, were found to interfere with the normal polarized delivery and exclusive segregation of hemagglutinin (HA) to the apical surface but not with the delivery and initial accumulation of G on the basolateral surface. Immunofluorescence analysis of permeabilized monolayers of influenza-infected MDCK cells treated with the microtubule-acting drugs demonstrated the presence of substantial amounts of HA protein on both the apical and basolateral surfaces. Moreover, in cells infected with the wild-type influenza virus, particles budded from both surfaces. Viral counts in electron micrographs showed that approximately 40% of the released viral particles accumulated in the intercellular spaces or were trapped between the cell and monolayer and the collagen support as compared to less than 1% on the basolateral surface of untreated infected cells. The effect of the microtubule inhibitors was not a result of a rapid redistribution of glycoprotein molecules initially delivered to the apical surface since a redistribution was not observed when the inhibitors were added to the cells after the HA was permitted to reach the apical surface at the permissive temperature and the synthesis of new HA was inhibited with cycloheximide. The altered segregation of the HA protein that occurs may result from the dispersal of the Golgi apparatus induced by the inhibitors or from the disruption of putative microtubules containing tracks that could direct vesicles from the trans Golgi apparatus to the cell surface. Since the vesicular stomatitis virus G protein is basolaterally segregated even when the Golgi elements are dispersed and hypothetical tracks disrupted, it appears that the two viral envelope glycoproteins are segregated by fundamentally different mechanisms and that the apical surface may be incapable of accepting vesicles carrying the G protein
— id: 55831, year: 1987, vol: 104, page: 231, stat: Journal Article,

SYNTHESIS AND SORTING TO LYSOSOMES OF BETA-GLUCURONIDASE IN TRANSFECTED CELLS
ANDY, R; ROSENFELD, M; ADESNIK, M; SABATINI, D
1986 NOV ;103(5):A359-A359, Journal of cell biology
— id: 41324, year: 1986, vol: 103, page: A359, stat: Journal Article,

BIOSYNTHESIS OF THE MAJOR INTEGRAL PROTEIN OF RAT PERIPHERAL-NERVE MYELIN
BROPHY, PJ; GILLESPIE, CS; COLMAN, DR; SABATINI, DD
1986 OCT ;14(5):859-859, Transactions (Biochemical Society (Great Britain))
— id: 41333, year: 1986, vol: 14, page: 859, stat: Journal Article,

POLARIZED DELIVERY AND RECYCLING IN MDCK CELLS OF A CHIMERIC PROTEIN CONTAINING THE LUMINAL PORTION OF VSV-G AND THE CYTOPLASMIC AND TRANSMEMBRANE DOMAIN OF INFLUENZA HA
Compton, T; Gottlieb, T; Rindler, M; Adesnik, M; Sabatini, DD
1986 NOV ;103(5):A7-A7, Journal of cell biology
— id: 51125, year: 1986, vol: 103, page: A7, stat: Journal Article,

BIOSYNTHESIS OF A CYSTEINE-RICH, HIGHLY GLYCOSYLATED PROTEIN PRESENT IN LYSOSOMAL AND ENDOSOMAL MEMBRANES
CROZE, E; IVANOV, I; SNITKIN, H; KREIBICH, G; SABATINI, DD; ROSENFELD, MG
1986 NOV ;103(5):A355-A355, Journal of cell biology
— id: 41323, year: 1986, vol: 103, page: A355, stat: Journal Article,

BIOSYNTHESIS OF THE 2',3'-CYCLIC NUCLEOTIDE PHOSPHOHYDROLASES OF RAT CENTRAL-NERVOUS-SYSTEM MYELIN
GILLESPIE, CS; BROPHY, PJ; COLMAN, DR; SABATINI, DD
1986 OCT ;14(5):859-859, Transactions (Biochemical Society (Great Britain))
— id: 41334, year: 1986, vol: 14, page: 859, stat: Journal Article,

PHENOTYPICAL DETERMINANTS IN EPITHELIAL-CELLS - STUDY USING NATIVE AND MODIFIED GENES OF VIRAL GLYCOPROTEINS
GONZALEZ, A; RIZZOLO, L; GOTTLIEB, T; SABATINI, DD
1986 NOV ;19(2):R158-R158, Archivos de biologia y medicina experimentalis
— id: 41313, year: 1986, vol: 19, page: R158, stat: Journal Article,

Secretion of endogenous and exogenous proteins from polarized MDCK cell monolayers
Gottlieb TA; Beaudry G; Rizzolo L; Colman A; Rindler M; Adesnik M; Sabatini DD
1986 Apr;83(7):2100-2104, Proceedings of the National Academy of Sciences of the United States of America
Confluent monolayers of MDCK (Madin-Darby canine kidney) cells provide a widely used system to study the biogenesis of epithelial cell polarity. We now report that these cells are also capable of the vectorial constitutive secretion of a major endogenous product, a glycoprotein of 81 kDa, which is released into the medium from the apical surface within 30 min of its synthesis. This release represents a bona fide exocytotic secretory process and is not the result of proteolytic cleavage of a plasma membrane-associated precursor since, in cells treated with chloroquine, a protein indistinguishable from the mature secretory product accumulated intracellularly. In contrast to the vectorial secretion of the endogenous product, a variety of exogenous exocrine and endocrine proteins synthesized in MDCK cells transfected with the corresponding genes were secreted from both the apical and basolateral surfaces. These included proteins such as rat growth hormone, chicken oviduct lysozyme, bovine gastric prochymosin, and rat salivary gland alpha 2u-globulin, which in their cells of origin are secreted via a regulated pathway, as well as the liver form of the alpha 2u-globulin and the immunoglobulin kappa chain, which are normally released constitutively. These results demonstrate the existence of secretory pathways that lead to both surfaces of MDCK cells and are accessible to the foreign secretory products. They are consistent with the operation of a sorting mechanism in which the polarized secretion of the endogenous product is effected through the recognition of signals that prevent its random distribution within the fluid phase in the cellular endomembrane system
— id: 35728, year: 1986, vol: 83, page: 2100, stat: Journal Article,

Sorting and endocytosis of viral glycoproteins in transfected polarized epithelial cells
Gottlieb TA; Gonzalez A; Rizzolo L; Rindler MJ; Adesnik M; Sabatini DD
1986 Apr;102(4):1242-1255, Journal of cell biology
Previous studies (Rindler, M. J., I. E., Ivanov, H. Plesken, and D. D. Sabatini, 1985, J. Cell Biol., 100: 136-151; Rindler, M. J., I. E. Ivanov, H. Plesken, E. J. Rodriguez-Boulan, and D. D. Sabatini, 1984, J. Cell Biol., 98: 1304-1319) have demonstrated that in polarized Madin-Darby canine kidney cells infected with vesicular stomatitis virus (VSV) or influenza virus the viral envelope glycoproteins G and HA are segregated to the basolateral and apical plasma membrane domains, respectively, where budding of the corresponding viruses takes place. Furthermore, it has been shown that this segregation of the glycoproteins reflects the polarized delivery of the newly synthesized polypeptides to each surface domain. In transfection experiments using eukaryotic expression plasmids that contain cDNAs encoding the viral glycoproteins, it is now shown that even in the absence of other viral components, both proteins are effectively segregated to the appropriate cell surface domain. In transfected cells, the HA glycoprotein was almost exclusively localized in the apical cell surface, whereas the G protein, although preferentially localized in the basolateral domains, was also present in lower amounts, in the apical surfaces of many cells. Using transfected and infected cells, it was demonstrated that, after reaching the cell surface, the G protein, but not the HA protein, undergoes interiorization by endocytosis. Thus, in the presence of chloroquine, a drug that blocks return of interiorized plasma membrane proteins to the cell surface, the G protein was quantitatively trapped in endosome- or lysosome-like vesicles. The sequestration of G was a rapid process that was completed in many cells by 1-2 h after chloroquine treatment. The fact that in transfected cells the surface content of G protein was not noticeably reduced during a 5-h incubation with cycloheximide, a protein synthesis inhibitor that did not prevent the effect of chloroquine, implies that normally, G protein molecules are not only interiorized but are also recycled to the cell surface
— id: 35729, year: 1986, vol: 102, page: 1242, stat: Journal Article,

PRESENCE OF A SPECIFIC GLYCOPROTEIN IN BOTH ENDOSOMAL AND LYSOSOMAL MEMBRANES
IVANOV, IE; CROZE, E; SNITKIN, H; PLESKEN, H; SABATINI, DD; ROSENFELD, MG
1986 NOV ;103(5):A354-A354, Journal of cell biology
— id: 41322, year: 1986, vol: 103, page: A354, stat: Journal Article,

CHARACTERIZATION AND BIOSYNTHESIS OF A RAT-LIVER MICROSOMAL ESTERASE
MARKS, AS; ROSENFELD, MG; SABATINI, DD; KREIBICH, G
1986 NOV ;103(5):A65-A65, Journal of cell biology
— id: 41318, year: 1986, vol: 103, page: A65, stat: Journal Article,

Small basic proteins of myelin from central and peripheral nervous systems are encoded by the same gene
Mentaberry A; Adesnik M; Atchison M; Norgard EM; Alvarez F; Sabatini DD; Colman DR
1986 Feb;83(4):1111-1114, Proceedings of the National Academy of Sciences of the United States of America
Peripheral nervous system (PNS) and central nervous system (CNS) rodent myelins, which are produced by different cell types, share common morphological and functional characteristics although their major integral membrane proteins are completely different. Both types of myelin however, contain sets of four myelin basic proteins (MBPs), which share similar immunochemical and electrophoretic properties. We have isolated and characterized cDNA clones corresponding to the rat mRNAs encoding the small MBPs (SMBPs) found in both CNS and PNS myelin. Sequence analysis of these clones indicate that SMBPs in both divisions of the nervous system are encoded by the same nucleotide sequences, which suggests that they are the products of the same gene expressed in both oligodendrocyte and Schwann cells. In dot-blot hybridization experiments with the CNS SMBP cDNA as a probe, it was shown that there is a 20-fold higher level of MBP mRNA in a CNS myelin fraction than in total brainstem mRNA. It also was found that in optic and sciatic nerves, which contain oligodendrocytes and Schwann cells respectively, there are higher levels (4-fold and 2-fold, respectively) of MBP mRNA than in brainstem. Blot-hybridization experiments showed that a probe derived from the coding region of the rat SMBP cDNA hybridizes to an homologous mRNA (approximately equal to 2.6 kilobases) present in human optic nerve, which is not detectable with a probe derived from the 3' untranslated region. This conservation of coding-region sequences is in accord with the highly homologous amino acid sequences reported for the MBPs in the two species
— id: 55810, year: 1986, vol: 83, page: 1111, stat: Journal Article,

SIGNALS FOR INSERTION OF CYTOCHROME-P-450 INTO ENDOPLASMIC- RETICULUM MEMBRANES
Monier, S; Vanluc, P; Kreibich, G; Sabatini, DD; Adesnik, M
1986 Nov;103(5):A290-A290, Journal of cell biology
— id: 31007, year: 1986, vol: 103, page: A290, stat: Journal Article,

Nucleotide sequence of rat preputial gland beta-glucuronidase cDNA and in vitro insertion of its encoded polypeptide into microsomal membranes
Nishimura Y; Rosenfeld MG; Kreibich G; Gubler U; Sabatini DD; Adesnik M; Andy R
1986 Oct;83(19):7292-7296, Proceedings of the National Academy of Sciences of the United States of America
We have selected the rat preputial gland beta-glucuronidase as a model protein to study the sorting of newly synthesized lysosomal hydrolases to the lysosome. The complete coding sequence of beta-glucuronidase messenger RNA was determined from the sequences of a group of overlapping cDNA clones isolated from preputial gland cDNA libraries. The beta-glucuronidase mRNA primary translation product contains 648 amino acids, including an amino-terminal signal sequence of 22 residues. The polypeptide has four potential sites for the addition of asparagine-linked core oligosaccharides. A 376-residue segment of beta-glucuronidase shows extensive homology (23% sequence identity) to a portion of Escherichia coli beta-galactosidase. This homology most likely reflects an evolutionary relationship between the bacterial and eukaryotic enzymes and the conservation of structural features necessary for the glycosidase activity of both proteins. Translation of mRNA synthesized in vitro by transcription of a cDNA containing the entire beta-glucuronidase coding region yielded a polypeptide that was immunoprecipitated with anti-beta-glucuronidase antiserum and had the same electrophoretic mobility as the primary translation product of natural beta-glucuronidase mRNA. In the presence of microsomal membranes, the in vitro-synthesized beta-glucuronidase underwent cotranslational incorporation into the microsomes, as indicated by removal of the signal sequence and the addition of several oligosaccharide chains. The beta-glucuronidase cDNA will provide a useful tool to study the mechanism of mannose phosphorylation and other aspects of the sorting of lysosomal enzymes to lysosomes
— id: 18422, year: 1986, vol: 83, page: 7292, stat: Journal Article,

NUCLEOTIDE-SEQUENCE OF RAT PREPUTIAL GLAND BETA-GLUCURONIDASE CDNA AND INVITRO INSERTION OF ITS ENCODED POLYPE
Nishimura, Y; Rosenfeld, MG; Kreibich, G; Gubler, U; Sabatini, DD; Adesnik, M; Andy, R
1986 Dec;11(4):534-534, Cell structure & function
— id: 31421, year: 1986, vol: 11, page: 534, stat: Journal Article,

ISOLATION AND CHARACTERIZATION OF CDNA CLONES FOR RIBOPHORIN-I - COMPLETE CODING SEQUENCE AND INVITRO SYNTHESIS AND INSERTION OF THE ENCODING PRODUCT INTO ER MEMBRANES
ORT, V; PRAKASH, K; COLMAN, DR; ROSENFELD, MG; ADESNIK, M; SABATINI, DD; KREIBICH, G
1986 NOV ;103(5):A65-A65, Journal of cell biology
— id: 41317, year: 1986, vol: 103, page: A65, stat: Journal Article,

NON-POLARIZED SECRETION OF FOREIGN SECRETORY PROTEINS IN TRANSFECTED MDCK CELLS
BEAUDRY G; GOTTLIEB T; ADESNIK M; RINDLER M; SABATINI D D
1985 ;101(5 PART 2):183A-183A, Journal of cell biology
— id: 104656, year: 1985, vol: 101, page: 183A, stat: Journal Article,

Polarized delivery of viral glycoproteins to the apical and basolateral plasma membranes of Madin-Darby canine kidney cells infected with temperature-sensitive viruses
Rindler MJ; Ivanov IE; Plesken H; Sabatini DD
1985 Jan;100(1):136-151, Journal of cell biology
The intracellular route followed by viral envelope glycoproteins in polarized Madin-Darby canine kidney cells was studied by using temperature-sensitive mutants of vesicular stomatitis virus (VSV) and influenza, in which, at the nonpermissive temperature (39.5 degrees C), the newly synthesized glycoproteins (G proteins) and hemagglutinin (HA), respectively, are not transported out of the endoplasmic reticulum. After infection with VSV and incubation at 39.5 degrees C for 4-5 h, synchronous transfer of G protein to the plasma membrane was initiated by shifting to the permissive temperature (32.5 degrees C). Immunoelectron microscopy showed that under these conditions the protein moved to the Golgi apparatus and from there directly to a region of the lateral plasma membrane near this organelle. G protein then seemed to diffuse progressively to basal regions of the cell surface and, only after it had accumulated in the basolateral domain, it began to appear on the apical surface near the intercellular junctions. The results of these experiments indicate that the VSV G protein must be sorted before its arrival at the cell surface, and suggest that passage to the apical domain occurs only late in infection when tight junctions are no longer an effective barrier. In complementary experiments, using the temperature-sensitive mutant of influenza, cultures were first shifted from the nonpermissive temperature (39.5 degrees C) to 18.5 degrees C, to allow entrance of the glycoprotein into the Golgi apparatus (see Matlin, K.S., and K. Simons, 1983, Cell, 34:233-243). Under these conditions HA accumulated in Golgi stacks and vesicles but did not reach the plasma membrane. When the temperature was subsequently shifted to 32.5 degrees C, HA rapidly appeared in discrete regions of the apical surface near, and often directly above, the Golgi elements, and later diffused throughout this surface. To ensure that the anti-HA antibodies had access to lateral domains, monolayers were treated with a hypertonic medium to dilate the intercellular spaces. Some labeling was then observed in the lateral plasma membranes soon after the shift, but this never increased beyond 1.0 gold particle/micron, whereas characteristic densities of labeling in apical surfaces soon became much higher (approximately 10 particles/micron). Our results suggest that the bulk of HA follows a direct pathway leading from the Golgi to regions of the apical surface close to trans-Golgi cisternae
— id: 55832, year: 1985, vol: 100, page: 136, stat: Journal Article,

INTRACELLULAR-TRANSPORT AND SORTING OF VIRAL GLYCOPROTEINS DESTINED FOR THE APICAL AND BASOLATERAL PLASMA-MEMBRANE DOMAINS OF CULTURED EPITHELIAL-CELLS
RINDLER, MJ; IVANOV, IE; GOTTLIEB, T; DELAROSA, AG; BEAUDRY, G; SABATINI, DD
1985 MAR ;55(3):A40-A40, Biology of the cell
— id: 41459, year: 1985, vol: 55, page: A40, stat: Journal Article,

Intracellular Sorting And Distinct Recycling Patterns Of Viral Glycoproteins In Polarized Epithelial Cells
Rizzolo L J; Gonzalez A; Gottlieb T A; Finidori J; Ivanov I E; Rindler M J; Adesnik MB; Sabatini DD
Protein transport and secretion Cold Spring Harbor, N.Y. : Cold Spring Harbor Laboratory, 1985,
— id: 5223, year: 1985, vol: , page: 147, stat: Chapter,

Biosynthesis and intracellular sorting of growth hormone-viral envelope glycoprotein hybrids
Rizzolo LJ; Finidori J; Gonzalez A; Arpin M; Ivanov IE; Adesnik M; Sabatini DD
1985 Oct;101(4):1351-1362, Journal of cell biology
Various aspects of the biogenetic mechanisms that are involved in the insertion of nascent plasma membrane proteins into the endoplasmic reticulum (ER) membrane and their subsequent distribution through the cell have been investigated. For these studies chimeric genes that encode hybrid proteins containing carboxy-terminal portions of the influenza virus hemagglutinin (154 amino acids) or the vesicular stomatitis virus envelope glycoprotein (G) (60 amino acids) linked to the carboxy terminus of a nearly complete secretory polypeptide, growth hormone (GH), were used. In in vitro transcription-translation experiments, it was found that the insertion signal in the GH portion of the chimeras led to incorporation of the membrane protein segments into the ER membrane. Effectively, GH became part of the luminal segment of membrane proteins of which only very small segments, corresponding to the cytoplasmic portions of the G or HA proteins, remained exposed on the surface of the microsomes. When the chimeric genes were expressed in transfected cells, the products, as expected, failed to be secreted and remained cell-associated. These results support the assignment of a halt transfer role to segments of the membrane polypeptides that include their transmembrane portions. The hybrid polypeptide containing the carboxy-terminal portion of HA linked to GH accumulated in a juxtanuclear region of the cytoplasm within modified ER cisternae, closely apposed to the Golgi apparatus. The location and appearance of these cisternae suggested that they represent overdeveloped transitional ER elements and thus may correspond to a natural way station between the ER and the Golgi apparatus, in which further transfer of the artificial molecules is halted. The GH-G hybrid could only be detected in transfected cells treated with chloroquine, a drug that led to its accumulation in the membranes of endosome or lysosome-like cytoplasmic vesicles. Although the possibility that the chimeric protein entered such vesicles directly from the Golgi apparatus cannot be ruled out, it appears more likely that it was first transferred to the cell surface and was then internalized by endocytosis
— id: 55811, year: 1985, vol: 101, page: 1351, stat: Journal Article,

Cell-to-cell communication in monolayers of epithelioid cells (MDCK) as a function of the age of the monolayer
Cereijido M; Robbins E; Sabatini DD; Stefani E
1984 ;81(1):41-48, Journal of membrane biology
We explore the existence of cell-to-cell communication in monolayers of MDCK cells plated at high densities so that they form a continuous monolayer in a few minutes. Lucifer Yellow CH is injected in the cytoplasm of a given cell by using a glass microelectrode with a fine tip (ca. 100 M omega) and passing square pulses of current of 1.0 nA that last 10 msec, every 20 msec, during 1 to 3 min. We then examine the monolayer with fluorescence microscopy. In 27 out of 111 cells injected during the first 4 to 15 hr after plating, the dye was transferred to neighboring cells. Electron micrographs of freeze-fracture replicas prepared at this time, show that 20 to 25% of the lateral surfaces present the aggregates of intramembrane particles typical of gap junctions. These early hours correspond to the formation of occluding junctions and polarization into an apical and a basolateral domain of the plasma membrane (Cereijido, Meza & Martinez-Palomo, 1981). Cell-to-cell coupling then decreases sharply and, in the period between the 1st and 3rd day (mature monolayers), only 4 out of 49 injected cells were able to transfer the dye to their neighbors in the monolayers. No image of gap junctions was found in freeze-fracture replicas of mature monolayers. The degree of coupling between cells, as well as the number of cells coupled to the injected one, were highly variable. The lack of coupling between cells in mature monolayers observed in this article with Lucifer Yellow CH and electron microscopy is in keeping with the absence of electrical coupling observed in a previous work (Stefani & Cereijido, 1983). The transient existence of communicating junctions observed in monolayers of MDCK cells is similar to that described in the literature for embryo tissues during development
— id: 55834, year: 1984, vol: 81, page: 41, stat: Journal Article,

IMMUNOLABELING OF FROZEN THIN-SECTIONS AND ITS APPLICATION TO THE STUDY OF THE BIOGENESIS OF EPITHELIAL-CELL PLASMA-MEMBRANES
IVANOV, IE; PLESKEN, H; SABATINI, DD; RINDLER, MJ
1984 ;20(2):199-216, Current topics in membranes & transport
— id: 40821, year: 1984, vol: 20, page: 199, stat: Journal Article,

QUANTITATIVE-ANALYSIS OF RIBOSOME-BINDING SITES IN RAT-LIVER MICROSOMAL SUBFRACTIONS
KREIBICH, G; SABATINI, DD; AMARCOSTESEC, A
1984 ;92(3):B93-B93, Archives internationales de physiolgoie de biochimie et de biophysique
— id: 40869, year: 1984, vol: 92, page: B93, stat: Journal Article,

RAT-LIVER ENDOPLASMIC-RETICULUM CONTAINS EQUIMOLAR AMOUNTS OF RIBOPHORINS AND RIBOSOMES
MARCANTONIO, EE; AMARCOSTESEC, A; SABATINI, DD; KREIBICH, G
1984 ;92(3):B95-B95, Archives internationales de physiolgoie de biochimie et de biophysique
— id: 40870, year: 1984, vol: 92, page: B95, stat: Journal Article,

Viral glycoproteins destined for apical or basolateral plasma membrane domains traverse the same Golgi apparatus during their intracellular transport in doubly infected Madin-Darby canine kidney cells
Rindler MJ; Ivanov IE; Plesken H; Rodriguez-Boulan E; Sabatini DD
1984 Apr;98(4):1304-1319, Journal of cell biology
Madin-Darby canine kidney (MDCK) cells can sustain double infection with pairs of viruses of opposite budding polarity (simian virus 5 [SV5] and vesicular stomatitis virus [VSV] or influenza and VSV), and we observed that in such cells the envelope glycoproteins of the two viruses are synthesized simultaneously and assembled into virions at their characteristic sites. Influenza and SV5 budded exclusively from the apical plasma membrane of the cells, while VSV emerged only from the basolateral surfaces. Immunoelectron microscopic examination of doubly infected MDCK cells showed that the influenza hemagglutinin (HA) and the VSV G glycoproteins traverse the same Golgi apparatus and even the same Golgi cisternae. This indicates that the pathways of the two proteins towards the plasma membrane do not diverge before passage through the Golgi apparatus and therefore that critical sorting steps must take place during or after passage of the glycoproteins through this organelle. After its passage through the Golgi, the HA accumulated primarily at the apical membrane, where influenza virion assembly occurred. A small fraction of HA did, however, appear on the lateral surface and was incorporated into the envelope of budding VSV virions. Although predominantly found on the basolateral surface, significant amounts of G protein were observed on the apical plasma membrane well before disruption of the tight junctions was detectable. Nevertheless, assembly of VSV virions was restricted to the basolateral domain and in doubly infected cells the G protein was only infrequently incorporated into the envelope of budding influenza virions. These observations indicate that the site of VSV budding is not determined exclusively by the presence of G polypeptides. Therefore, it is likely that, at least for VSV, other cellular or viral components are responsible for the selection of the appropriate budding domain
— id: 55833, year: 1984, vol: 98, page: 1304, stat: Journal Article,

MICROTUBULE-ACTING DRUGS INTERFERE WITH THE DELIVERY OF INFLUENZA HEMAGGLUTININ (HA) TO THE APICAL PLASMA-MEMBRANE OF MDCK CELLS
RINDLER, MJ; IVANOV, IE; SABATINI, DD
1984 ;99(4):A6-A6, Journal of cell biology
— id: 40890, year: 1984, vol: 99, page: A6, stat: Journal Article,

INTRACELLULAR-TRANSPORT OF GROWTH HORMONE-MEMBRANE PROTEIN HYBRIDS
RIZZOLO, LJ; ADESNIK, M; SABATINI, DD
1984 ;99(4):A100-A100, Journal of cell biology
— id: 50830, year: 1984, vol: 99, page: A100, stat: Journal Article,

Biosynthesis and processing of ribophorins in the endoplasmic reticulum
Rosenfeld MG; Marcantonio EE; Hakimi J; Ort VM; Atkinson PH; Sabatini D; Kreibich G
1984 Sep;99(3):1076-1082, Journal of cell biology
Ribophorins are two transmembrane glycoproteins characteristic of the rough endoplasmic reticulum, which are thought to be involved in the binding of ribosomes. Their biosynthesis was studied in vivo using lines of cultured rat hepatocytes (clone 9) and pituitary cells (GH 3.1) and in cell-free synthesis experiments. In vitro translation of mRNA extracted from free and bound polysomes of clone 9 cells demonstrated that ribophorins are made exclusively on bound polysomes. The primary translation products of ribophorin messengers obtained from cultured hepatocytes or from regenerating livers co-migrated with the respective mature proteins, but had slightly higher apparent molecular weights (2,000) than the unglycosylated forms immunoprecipitated from cells treated with tunicamycin. This indicates that ribophorins, in contrast to all other endoplasmic reticulum membrane proteins previously studied, contain transient amino-terminal insertion signals which are removed co-translationally. Kinetic and pulse-chase experiments with [35S]methionine and [3H]mannose demonstrated that ribophorins are not subjected to electrophoretically detectable posttranslational modifications, such as proteolytic cleavage or trimming and terminal glycosylation of oligosaccharide side chain(s). Direct analysis of the oligosaccharides of ribophorin l showed that they do not contain the terminal sugars characteristic of complex oligosaccharides and that they range in composition from Man8GlcNAc to Man5GlcNAc. These findings, as well as the observation that the mature proteins are sensitive to endoglycosidase H and insensitive to endoglycosidase D, are consistent with the notion that the biosynthetic pathway of the ribophorins does not require a stage of passage through the Golgi apparatus
— id: 18428, year: 1984, vol: 99, page: 1076, stat: Journal Article,

FUNCTIONAL TRANSLOCATION SITES FOR NEWLY SYNTHESIZED SECRETORY PROTEINS ARE SEGREGATED IN THE ROUGH DOMAIN OF THE RAT-LIVER ENDOPLASMIC-RETICULUM
TODD, JA; KREIBICH, G; SABATINI, DD; AMARCOSTESEC, A
1984 ;92(3):B108-B109, Archives internationales de physiolgoie de biochimie et de biophysique
— id: 40871, year: 1984, vol: 92, page: B108, stat: Journal Article,

AN 83 KD POLYPEPTIDE IS A COMPONENT OF THE PROTEIN TRANSLOCATION APPARATUS OF THE ROUGH ENDOPLASMIC-RETICULUM
TODD, JA; SABATINI, DD; KREIBICH, G
1984 ;99(4):A2-A2, Journal of cell biology
— id: 40889, year: 1984, vol: 99, page: A2, stat: Journal Article,

Biosynthesis of myelin-specific proteins
Colman DR; Kreibich G; Sabatini DD
1983 ;96(3):378-385, Methods in enzymology
— id: 18435, year: 1983, vol: 96, page: 378, stat: Journal Article,

HUMAN AND OVINE PRECURSORS OF CORTICOTROPIN-RELEASING FACTOR (CRF)
FREY, AB; AUDHYA, TK; HOLLANDER, CS; NELSON, K; KREIBICH, G; SABATINI, D; SCHLESINGER, DH
1983 ;42(3):356-356, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 40722, year: 1983, vol: 42, page: 356, stat: Journal Article,

Participation of plasma membrane proteins in the formation of tight junctions by cultured epithelial cells
Griepp EB; Dolan WJ; Robbins ES; Sabatini DD
1983 Mar;96(3):693-702, Journal of cell biology
— id: 55835, year: 1983, vol: 96, page: 693, stat: Journal Article,

DISTRIBUTION, BIOSYNTHESIS AND PHYSIOLOGICAL-ROLE OF OVINE CORTICOTROPIN RELEASING-FACTOR IN MAN
HOLLANDER, CS; AUDHYA, T; FREY, A; KREIBICH, G; SABATINI, D; NAKANE, T; KAGEYAMA, N; KUWAYAMA, A; GOLBE, L; SCHLESINGER, D
1983 ;31(2):A528-A528, Clinical research
— id: 40552, year: 1983, vol: 31, page: A528, stat: Journal Article,

Ribophorins I and II: membrane proteins characteristic of the rough endoplasmic reticulum
Kreibich G; Marcantonio EE; Sabatini DD
1983 ;96(3):520-530, Methods in enzymology
— id: 18434, year: 1983, vol: 96, page: 520, stat: Journal Article,

Biosynthesis of hepatocyte endoplasmic reticulum proteins
Kreibich G; Sabatini DD; Adesnik M
1983 ;96(3):530-542, Methods in enzymology
— id: 18433, year: 1983, vol: 96, page: 530, stat: Journal Article,

INCORPORATION OF PROTEINS INTO CELLULAR MEMBRANES AND ORGANELLES
KREIBICH, G; COLMAN, D; ROSENFELD, MG; SABATINI, DD
1983 ;364(9):1164-1165, Hoppe-Seylers zeitschrift fur physiologische Chemie
— id: 40628, year: 1983, vol: 364, page: 1164, stat: Journal Article,

ISOLATION AND CHARACTERIZATION OF CDNA CLONES FOR THE MYELIN BASIC-PROTEINS
MENTABERRY, A; ADESNIK, M; KREIBICH, G; SABATINI, DD; COLMAN, D
1983 ;97(5):A244-A244, Journal of cell biology
— id: 40497, year: 1983, vol: 97, page: A244, stat: Journal Article,

BIOSYNTHESIS OF RAT-BRAIN NA,K-ATPASE
NABI, N; SHERMAN, J; SABATINI, DD; MORIMOTO, T
1983 ;97(5):A117-A117, Journal of cell biology
— id: 40494, year: 1983, vol: 97, page: A117, stat: Journal Article,

ISOLATION AND CHARACTERIZATION OF CDNA CLONES FOR BETA-GLUCURONIDASE
NISHIMURA, Y; ROSENFELD, M; KREIBICH, G; ADESNIK, M; SABATINI, DD
1983 ;97(5):A103-A103, Journal of cell biology
— id: 40491, year: 1983, vol: 97, page: A103, stat: Journal Article,

Assembly of enveloped viruses in Madin-Darby canine kidney cells: polarized budding from single attached cells and from clusters of cells in suspension
Rodriguez-Boulan E; Paskiet KT; Sabatini DD
1983 Mar;96(3):866-874, Journal of cell biology
In confluent monolayers of the dog kidney epithelial cell line Madin-Darby canine kidney (MDCK) assembly of RNA enveloped viruses reflects the functional polarization of the cells. Thus, influenza, Sendai, and Simian virus 5 bud from the apical (free) surface, while vesicular stomatitis virions (VSV) are assembled at basolateral plasma membrane domains (Rodriguez-Boulan, E., and D.D. Sabatini, 1978, Proc. Natl. Acad. Sci. U.S.A., 75:5071-5075). MDCK cells derived from confluent monolayers by dissociation with trypsin-EDTA and maintained as single cells in spinner medium for 12-20 h before infection, lose their characteristic structural polarity. Furthermore, when these cells were infected with influenza or VSV, virions assembled in a nonpolarized fashion over most of the cell surface. However, when dissociated MDCK cells infected in suspension were sparsely plated on collagen gels to prevent intercellular contact and the formation of junctions, the characteristic polarity of viral budding observed in confluent monolayers was again manifested; i.e., VSV budded preferentially from adherent surfaces and influenza almost exclusively from free surface regions. Similar polarization was observed in cells which became aggregated during incubation in spinner medium: influenza budded from the free surface, while VSV was produced at regions of cell-cell contact. It therefore appears that in isolated epithelial cells attachment to a substrate or to another cell is sufficient to trigger the expression of plasma membrane polarity which is manifested in the asymmetric budding of viruses
— id: 55836, year: 1983, vol: 96, page: 866, stat: Journal Article,

Biosynthesis of lysosomal enzymes
Rosenfeld MG; Kreibich G; Sabatini DD; Kato K
1983 ;96(3):764-777, Methods in enzymology
— id: 18432, year: 1983, vol: 96, page: 764, stat: Journal Article,

IDENTIFICATION OF A PROTEIN CHARACTERISTIC OF THE LYSOSOMAL MEMBRANE USING MONOCLONAL-ANTIBODIES
ROSENFELD, M; DOLAN, W; SABATINI, D; KREIBICH, G
1983 ;97(5):A106-A106, Journal of cell biology
— id: 40492, year: 1983, vol: 97, page: A106, stat: Journal Article,

MECHANISMS FOR THE DISTRIBUTION OF PROTEINS IN EUKARYOTIC CELLS
SABATINI, DD
1983 ;16(2):R105-R106, Archivos de biologia y medicina experimentalis
— id: 40588, year: 1983, vol: 16, page: R105, stat: Journal Article,

STUDIES ON THE BIOSYNTHESIS OF PLASMA-MEMBRANE PROTEINS
SABATINI, DD
1983 ;16(2):R111-R113, Archivos de biologia y medicina experimentalis
— id: 40589, year: 1983, vol: 16, page: R111, stat: Journal Article,

BIOSYNTHESIS OF THE NA,K-ATPASE IN MDCK CELLS
SHERMAN, J; MORIMOTO, T; SABATINI, DD
1983 ;19(5):753-764, Current topics in membranes & transport
— id: 40505, year: 1983, vol: 19, page: 753, stat: Journal Article,

MEMBRANE ORIENTATION OF THE NA,K-ATPASE
SHERMAN, JM; NABI, N; SABATINI, DD; MORIMOTO, T
1983 ;97(5):A116-A116, Journal of cell biology
— id: 40493, year: 1983, vol: 97, page: A116, stat: Journal Article,

Synthesis and incorporation of myelin polypeptides into CNS myelin
Colman DR; Kreibich G; Frey AB; Sabatini DD
1982 Nov;95(2 Pt 1):598-608, Journal of cell biology
The distribution of newly synthesized proteolipid protein (PLP, 23 kdaltons) and myelin basic proteins (MBPs, 14-21.5 kdaltons) was determined in microsomal and myelin fractions prepared from the brainstems o1 10-30 d-old rats sacrificed at different times after an intracranial injection of 35S-methionine. Labeled MBPs were found in the myelin fraction 2 min after the injection, whereas PLP appeared first in the rough microsomal fraction and only after a lag of 30 min in the myelin fraction. Cell-free translation experiments using purified mRNAs demonstrated that PLP and MBPs are synthesized in bound and free polysomes, respectively. A mechanism involving the cotranslational insertion into the ER membrane and subsequent passage of the polypeptides through the Golgi apparatus is consistent with the lag observed in the appearance of the in vivo-labeled PLP in the myelin membrane. Newly synthesized PLP and MBPs are not proteolytically processed, because the primary translation products synthesized in vitro had the same electrophoretic mobility and N-terminal amino acid sequence as the mature PLP and MBP polypeptides. It was found that crude myelin fractions are highly enriched in mRNAs coding for the MBPs but not in mRNA coding for PLP. This suggests that whereas the bound polysomes synthesizing PLP are largely confined to the cell body, free polysomes synthesizing MBPs are concentrated in oligodendrocyte processes involved in myelination, which explains the immediate incorporation of MBPs into the developing myelin sheath
— id: 18436, year: 1982, vol: 95, page: 598, stat: Journal Article,

POLARIZED DISTRIBUTION OF SUGAR RESIDUES IN THE GOLGI-APPARATUS
Delemos, C; Kreibich, G; Rodriguezboulan, E; Sabatini, DD
1982 ;95(2):A404-A404, Journal of cell biology
— id: 30516, year: 1982, vol: 95, page: A404, stat: Journal Article,

Recovery of ribophorins and ribosomes in "inverted rough" vesicles derived from rat liver rough microsomes
Kreibich G; Ojakian G; Rodriguez-Boulan E; Sabatini DD
1982 Apr;93(1):111-121, Journal of cell biology
Treatment of rat liver rough microsomes (3.5 mg of protein/ml) with sublytical concentrations (0.08%) of the neutral detergent Triton X-100 caused a lateral displacement of bound ribosomes and the formation of ribosomal aggregates on the microsomal surface. At slightly higher detergent concentrations (0.12-0.16%) membrane areas bearing ribosomal aggregates invaginated into the microsomal lumen and separated from the rest of the membrane. Two distinct classes of vesicles could be isolated by density gradient centrifugation from microsomes treated with 0.16% Triton X-100: one with ribosomes bound to the inner membrane surfaces ('inverted rough' vesicles) and another with no ribosomes attached to the membranes. Analysis of the fractions showed that approximately 30% of the phospholipids and 20-30% of the total membrane protein were released from the membranes by this treatment. Labeling with avidin-ferritin conjugates demonstrated that concanavalin A binding sites, which in native rough microsomes are found in the luminal face of the membranes, were present on the outer surface of the inverted rough vesicles. Freeze-fracture electron microscopy showed that both fracture faces had similar concentrations of intramembrane particles. SDS PAGE analysis of the two vesicle subfractions demonstrated that, of all the integral microsomal membrane proteins, only ribophorins I and II were found exclusively in the inverted rough vesicles bearing ribosomes. These observations are consistent with the proposal that ribophorins are associated with the ribosomal binding sites characteristic of rough microsomal membranes
— id: 18439, year: 1982, vol: 93, page: 111, stat: Journal Article,

Identification of ribophorins in rough microsomal membranes from different organs of several species
Marcantonio EE; Grebenau RC; Sabatini DD; Kreibich G
1982 May;124(1):217-222, European journal of biochemistry
Microsomes prepared from several animal sources were analyzed for the presence of proteins corresponding to the ribophorins (I and II) which have been previously characterized in rat liver rough microsomes and appear to be involved in the binding of polysomes to endoplasmic reticulum membranes. In rough microsomal membranes from rat lacrimal gland, rabbit liver, dog and chicken pancreas, and mouse myeloma, ribophorin-like polypeptides with similar electrophoretic mobilities were detected by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. In all cases the polypeptides remained associated with sedimentable polysomes after solubilization of the microsomal membranes with nonionic detergents. Ribophorin-like polypeptides were absent from smooth microsomes. Antibodies raised against each rat liver ribophorin, purified by preparative sodium dodecyl sulfate/polyacrylamide gel electrophoresis, immunoprecipitated only the corresponding polypeptide, indicating no crossreactivity between ribophorins I and II. These antibodies also immunoprecipitated the homologous ribophorins found in microsomal preparations from other organs and species
— id: 18437, year: 1982, vol: 124, page: 217, stat: Journal Article,

Studies on the biosynthesis of microsomal membrane proteins. Site of synthesis and mode of insertion of cytochrome b5, cytochrome b5 reductase, cytochrome P-450 reductase and epoxide hydrolase
Okada Y; Frey AB; Guenthner TM; Oesch F; Sabatini DD; Kreibich G
1982 Feb;122(2):393-402, European journal of biochemistry
— id: 18440, year: 1982, vol: 122, page: 393, stat: Journal Article,

Biogenesis of epithelial cell plasma membranes
Rindler MJ; Ivanov IE; Rodriguez-Boulan EJ; Sabatini DD
1982 ;(92):184-208, CIBA Foundation symposium
Polarized monolayers of cultured epithelial cells, such as the kidney-derived MDCK cell line, when infected with enveloped viruses, provide a convenient model system for study of the intracellular routes followed by newly synthesized glycoproteins to reach specific domains of the plasma membrane. The polarized nature of the monolayers is reflected in the asymmetric assembly of enveloped viruses, some of which, such as influenza and simian virus 5 (SV5), bud from the apical surfaces of the cells, while others, such as vesicular stomatitis virus (VSV), emerge from the basolateral surfaces. MDCK cells can sustain double infection with viruses of different budding polarity, and within such cells the envelope glycoproteins of the two viruses are synthesized simultaneously and assembled into virions at different sites. Immunoelectron microscopic observations of doubly infected cells show that glycoproteins of influenza and VSV traverse the same Golgi apparatus. This indicates that critical sorting steps must take place during or after passage of the glycoproteins through the organelle. Following passage through the Golgi, the HA glycoprotein accumulates almost exclusively at the apical surface, where the influenza virions assemble. Significant amounts of the G protein, however, are detected on both plasma membranes in singly and doubly infected cells, although VSV virion assembly is limited to basolateral domains. These observations indicate that the site of VSV budding is not exclusively determined by the presence of G polypeptides on a given cell-surface domain. It is possible that other cellular or viral components are responsible for the selection of the appropriate budding domain or that the G protein found on the apical surface must be transferred to the basolateral domain before it becomes competent for assembly
— id: 55837, year: 1982, vol: , page: 184, stat: Journal Article,

MEMBRANE LOCALIZATION OF VIRAL GLYCOPROTEINS IN POLARIZED EPITHELIAL-CELLS
Rindler, MJ; Ivanov, IE; Sabatini, DD
1982 ;95(2):A262-A262, Journal of cell biology
— id: 30514, year: 1982, vol: 95, page: A262, stat: Journal Article,

Biosynthesis of lysosomal hydrolases: their synthesis in bound polysomes and the role of co- and post-translational processing in determining their subcellular distribution
Rosenfeld MG; Kreibich G; Popov D; Kato K; Sabatini DD
1982 Apr;93(1):135-143, Journal of cell biology
— id: 18438, year: 1982, vol: 93, page: 135, stat: Journal Article,

Mechanisms for the incorporation of proteins into the plasma membrane
Sabatini D; Colman D; Sabban E; Sherman J; Morimoto T; Kreibich G; Adesnik M
1982 ;46 Pt 2(1):807-818, Cold Spring Harbor symposia on quantitative biology
— id: 18442, year: 1982, vol: 46 Pt 2, page: 807, stat: Journal Article,

Mechanisms for the incorporation of proteins in membranes and organelles
Sabatini DD; Kreibich G; Morimoto T; Adesnik M
1982 Jan;92(1):1-22, Journal of cell biology
— id: 18441, year: 1982, vol: 92, page: 1, stat: Journal Article,

BIOSYNTHESIS OF CNS MYELIN MEMBRANE-PROTEINS
Colman, DR; Kreibich, G; Frey, AB; Sabatini, DD
1981 ;91(2):A404-A404, Journal of cell biology
— id: 30541, year: 1981, vol: 91, page: A404, stat: Journal Article,

ROLE OF MICROFILAMENTS IN TIGHT JUNCTION FORMATION
Griepp, EB; Robbins, ES; Dolan, WJ; Sabatini, DD
1981 ;91(2):A118-A118, Journal of cell biology
— id: 30537, year: 1981, vol: 91, page: A118, stat: Journal Article,

Surface features and handedness of a model for the eukaryotic small ribosomal subunit
Ivanov IE; Sabatini DD
1981 Sep;76(3):263-276, Journal of ultrastructure research
— id: 55838, year: 1981, vol: 76, page: 263, stat: Journal Article,

ROLE OF RIBOPHORINS IN THE BINDING OF PRE-SECRETORY PROTEINS TO MICROSOMAL-MEMBRANES
Marcantonio, EE; Sabatini, DD; Kreibich, G
1981 ;91(2):A403-A403, Journal of cell biology
— id: 30540, year: 1981, vol: 91, page: A403, stat: Journal Article,

In vitro synthesis and posttranslational uptake of cytochrome c into isolated mitochondria: role of a specific addressing signal in the apocytochrome
Matsuura S; Arpin M; Hannum C; Margoliash E; Sabatini DD; Morimoto T
1981 Jul;78(7):4368-4372, Proceedings of the National Academy of Sciences of the United States of America
Administration of the thyroid hormone 3,3,5'-triiodo-L-thyronine (T3) to rats leads to a marked increase in hepatic levels of mRNA for cytochrome c. Messenger RNA prepared from the free polysomes of T3-treated rats directed the in vitro synthesis of a polypeptide which only differed in amino acid sequence from mature cytochrome c in that it contained an NH2-terminal methionine. The in vitro product was incorporated specifically into purified rat liver mitochondria and became inaccessible to added trypsin when the mitochondria were added after translation was completed. Horse heart apocytochrome c, but not the holocytochrome, could compete with the in vitro synthesized polypeptide for its uptake into mitochondria. This suggests that the primary structural features of apocytochrome c, which serve as an addressing signal for mitochondria, are masked after the acquisition of heme and that this process occurs in the mitochondria. The addressing signal seems to be contained in a specific segment of the cytochrome polypeptide because only one fragment generated by CNBr cleavage of horse apocytochrome c, extending from residue 66 to the carboxy end of the molecule, could compete with the in vitro product for its transfer into mitochondria
— id: 55839, year: 1981, vol: 78, page: 4368, stat: Journal Article,

SIMULTANEOUS BUDDING OF VIRUSES WITH OPPOSITE POLARITY FROM DOUBLY INFECTED MDCK CELLS
Rindler, MJ; Ivanov, IE; Rodriguezboulan, E; Sabatini, DD
1981 ;91(2):A118-A118, Journal of cell biology
— id: 30538, year: 1981, vol: 91, page: A118, stat: Journal Article,

ASYMMETRIC BUDDING OF ENVELOPED VIRUSES FROM ISOLATED EPITHELIAL-CELLS ATTACHED TO A COLLAGEN SUBSTRATE
Rodriguezboulan, EJ; Paskiet, KT; Sabatini, DD
1981 ;91(2):A121-A121, Journal of cell biology
— id: 30403, year: 1981, vol: 91, page: A121, stat: Journal Article,

SYNTHESIS AND COTRANSLATIONAL PROCESSING OF RIBOPHORINS
Rosenfeld, MG; Marcantonio, EE; Harnik, VM; Sabatini, DD; Kreibich, G
1981 ;91(2):A404-A404, Journal of cell biology
— id: 30542, year: 1981, vol: 91, page: A404, stat: Journal Article,

Membrane And Organelle Biogenesis A Brief Synopsis Of Current Concepts
Sabatini DD; Kreibich G; Morimoto T; Adesnik M
Mitochondria and microsomes : in honor of Lars Ernster / Reading, Mass. : Addison-Wesley, 1981,
— id: 5224, year: 1981, vol: , page: 563, stat: Chapter,

Erythrocyte membrane protein band 3: its biosynthesis and incorporation into membranes
Sabban E; Marchesi V; Adesnik M; Sabatini DD
1981 Dec;91(3 Pt 1):637-646, Journal of cell biology
Band 3, a transmembrane protein that provides the anion channel of the erythrocyte plasma membrane, crosses the membrane more than once and has a large amino terminal segment exposes on the cytoplasmic side of the membrane. The biosynthesis of band 3 and the process of its incorporation into membranes were studied in vivo in erythroid spleen cells of anemic mice and in vitro in protein synthesizing cell-free systems programmed with polysomes and messenger RNA (mRNA). In intact cells newly synthesized band 3 is rapidly incorporated into intracellular membranes where it is glycosylated and it is subsequently transferred to the plasma membrane where it becomes sensitive to digestion by exogenous chymotrypsin. The appearance of band 3 in the cell surface is not contingent upon its glycosylation because it proceeds efficiently in cells treated with tunicamycin. The site of synthesis of band 3 in bound polysomes was established directly by in vitro translation experiments with purified polysomes or with mRNA extracted from them. The band-3 polypeptide synthesized in an mRNA-dependent system had the same electrophoretic mobility as that synthesized in cells treated with tunicamycin. When microsomal membranes were present during translation, the in vitro synthesized band-3 polypeptide was cotranslationally glycosylated and inserted into the membranes. This was inferred from the facts that when synthesis was carried out in the presence of membranes the product had a lower electrophoretic mobility and showed partial resistance to protease digestion. Our observations indicate that the primary translation product of band-3 mRNA is not proteolytically processed either co- or posttranslationally. It is, therefore, proposed that the incorporation of band 3 into the endoplasmic reticulum (ER) membrane is initiated by a permanent insertion signal. To account for the cytoplasmic exposure of the amino terminus of the polypeptide we suggest that this signal is located within the interior of the polypeptide. a mechanism that explains the final transmembrane disposition of band 3 in the plasma membrane as resulting from the mode of its incorporation into the ER is presented
— id: 55812, year: 1981, vol: 91, page: 637, stat: Journal Article,

A SEGMENT OF CYTOCHROME-C CONTAINING INFORMATION FOR THE UPTAKE OF NEWLY SYNTHESIZED CYTOPLASMIC POLYPEPTIDES BY MITOCHONDRIA
Arpin, M; Matsuura, S; Margoliash, E; Sabatini, DD; Morimoto, T
1980 ;22(1):151-151, European journal of cell biology
— id: 28097, year: 1980, vol: 22, page: 151, stat: Journal Article,

Synthesis and insertion of cytochrome P-450 into endoplasmic reticulum membranes
Bar-Nun S; Kreibich G; Adesnik M; Alterman L; Negishi M; Sabatini DD
1980 Feb;77(2):965-969, Proceedings of the National Academy of Sciences of the United States of America
Treatment of rats with phenobarbital leads to a substantial increase in levels of translatable liver cytochrome P-450 mRNA. This mRNA is primarily associated with ribosomes bound to endoplasmic reticulum membranes which in an in vitro system synthesized approximately 10 times more cytochrome P-450 than did free polysomes from the same animals. Cytochrome P-450 synthesized by rough microsomes in vitro appears to be directly inserted into the membranes because it was not released by a treatment with low detergent concentrations that released albumin and other microsomal content proteins. The amino-terminal amino acid sequence of cytochrome P-450 synthesized in an mRNA-dependent system resembles in hydrophobicity the signal segment of presecretory proteins and therefore may serve to insert the polypeptide into the membrane during synthesis. In contrast to the situation with secretory proteins and several other membrane proteins, however, the putative insertion signal of cytochrome P-450 is not removed by a membrane-associated peptidase and remains in the mature polypeptide
— id: 18444, year: 1980, vol: 77, page: 965, stat: Journal Article,

INVITRO POSTTRANSLATIONAL MODIFICATION OF THE G-PROTEIN OF VESICULAR STOMATITIS-VIRUS FOLLOWING FUSION OF ROUGH AND SMOOTH MICROSOMAL VESICLES FROM HELA-CELLS
Gaetani, S; Waldman, F; Feldman, R; Sabatini, DD; Morimoto, T
1980 ;87(2):A308-A308, Journal of cell biology
— id: 28092, year: 1980, vol: 87, page: A308, stat: Journal Article,

Functional and structural characteristics of endoplasmic reticulum proteins associated with ribosome binding sites
Kreibich G; Czako-Graham M; Grebenau RC; Sabatini DD
1980 ;343(2):17-33, Annals of the New York Academy of Sciences
— id: 18445, year: 1980, vol: 343, page: 17, stat: Journal Article,

STRUCTURAL AND FUNCTIONAL-CHARACTERISTICS OF ENDOPLASMIC- RETICULUM MEMBRANE-PROTEINS RELATED TO TRANSLATION ON BOUND POLYSOMES
Kreibich, G; Sabatini, DD
1980 ;22(1):153-153, European journal of cell biology
— id: 28098, year: 1980, vol: 22, page: 153, stat: Journal Article,

IMMUNOLOGICAL CROSSREACTIVITY OF RAT-LIVER RIBOPHORINS WITH SIMILAR PROTEINS IN OTHER ORGANS AND SPECIES
Marcantonio, EE; Rosenfeld, MG; Sabatini, DD; Kreibich, G
1980 ;87(2):A208-A208, Journal of cell biology
— id: 28088, year: 1980, vol: 87, page: A208, stat: Journal Article,

SYNTHESIS AND MATURATION OF LYSOSOMAL PROTEINS
Rosenfeld, M; Sabatini, DD; Sabban, E; Kato, K; Kreibich, C
1980 ;87(2):A308-A308, Journal of cell biology
— id: 28091, year: 1980, vol: 87, page: A308, stat: Journal Article,

FUNCTIONS OF MEMBRANE-BOUND RIBOSOMES IN EUKARYOTIC CELLS
Sabatini, DD
1980 ;5(3):371-371, Ultramicroscopy
— id: 27979, year: 1980, vol: 5, page: 371, stat: Journal Article,

Biosynthesis of erythrocyte membrane protein band 3 in DMSO-induced Friend erythroleukemia cells
Sabban EL; Sabatini DD; Marchesi VT; Adesnik M
1980 Aug;104(2):261-268, Journal of cellular physiology
The major integral membrane protein of red blood cells, the mouse equivalent of human band 3, was purified and used to raise a specfic antiserum. The murine protein resembles its human counterpart in several of its properties, including susceptibility to digestion by chymotrypsin added to intact cells and an ability to bind to concanavalin A. The synthesis of 35S-labeled band 3 was detected in Friend erythroleukemia cells treated with DMSO by immuneprecipitation followed by SDS gel electrophoresis and fluorography. Induction with DMSO led to a greater than tenfold increase in the synthesis of band 3 and maximal synthesis was reached 3 to 4 days after the beginning of induction
— id: 55813, year: 1980, vol: 104, page: 261, stat: Journal Article,

SYNTHESIS AND COTRANSLATIONAL PROCESSING OF ERYTHROCYTE- MEMBRANE PROTEIN BAND-3 BY MICROSOMAL-MEMBRANES
Sabban, E; Marchesi, V; Adesnik, M; Sabatini, DD
1980 ;87(2):A307-A307, Journal of cell biology
— id: 28089, year: 1980, vol: 87, page: A307, stat: Journal Article,

STUDIES ON THE BIOSYNTHESIS OF THE POLYPEPTIDE SUBUNITS OF THE NA,K-ATPASE OF KIDNEY-CELLS
Sherman, JM; Sabatini, DD; Morimoto, T
1980 ;87(2):A307-A307, Journal of cell biology
— id: 28090, year: 1980, vol: 87, page: A307, stat: Journal Article,

Effect of protease inhibitors on albumin secretion in hepatoma cells
Algranati ID; Sabatini DD
1979 Sep 12;90(1):220-226, Biochemical & biophysical research communications
— id: 55840, year: 1979, vol: 90, page: 220, stat: Journal Article,

In vitro synthesis of the Ca2+ transport ATPase by ribosomes bound to sarcoplasmic reticulum membranes
Chyn TL; Martonosi AN; Morimoto T; Sabatini DD
1979 Mar;76(3):1241-1245, Proceedings of the National Academy of Sciences of the United States of America
— id: 55841, year: 1979, vol: 76, page: 1241, stat: Journal Article,

RECONSTITUTION OF MICROSOMAL VESICLES CONTAINING THE SIGNAL PE
Czakograham, M; Boime, I; Sabatini, DD; Kreibich, G
1979 ;38(3):620-620, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 30044, year: 1979, vol: 38, page: 620, stat: Journal Article,

MEMBRANE-BOUND RIBOSOMES IN ENDOPLASMIC-RETICULUM
Sabatini, DD; Kreibich, G
1979 ;5(1-2):134-134, Molecular biology reports
— id: 30093, year: 1979, vol: 5, page: 134, stat: Journal Article,

BIOSYNTHESIS OF MURINE ERYTHROCYTE MEMBRANE PROTEIN BAND 3
SABBAN E; SABATINI D; ADESNIK M; MARCHESI V
1979 ;83(2 PART 2):437A-437A, Journal of cell biology
— id: 104657, year: 1979, vol: 83, page: 437A, stat: Journal Article,

Asymmetric budding of viruses in epithelial monlayers: a model system for study of epithelial polarity
Boulan ER; Sabatini DD
1978 Oct;75(10):5071-5075, Proceedings of the National Academy of Sciences of the United States of America
Infection of two different lines of polarized epithelial cells grown as monolayers with several types of enveloped viruses results, for each virus type, in a characteristic asymmetric budding of virions. Influenza virus (WSN strain), simian virus 5, and Sendai virus bud exclusively from the free (apical) surface of the cells, while vesicular stomatitis virus acquires its envelope only from the basolateral plasma membrane. Because different viruses select specific domains of plasma membrane in the same cell type, virus-infected epithelial monolayers can provide an excellent model system for studies of the mechanisms that generate regional differences in the distribution of plasma membrane components of epithelial cells
— id: 55842, year: 1978, vol: 75, page: 5071, stat: Journal Article,

Polarized monolayers formed by epithelial cells on a permeable and translucent support
Cereijido M; Robbins ES; Dolan WJ; Rotunno CA; Sabatini DD
1978 Jun;77(3):853-880, Journal of cell biology
An epithelial cell line (MDCK) was used to prepare monolayers which, in vitro, develop properties of transporting epithelia. Monolayers were formed by plating cells at high densities (10(6) cells/cm2) on collagen-coated nylon cloth disks to saturate the area available for attachment, thus avoiding the need for cell division. An electrical resistance developed within 4-6 h after plating and achieved a steady-state value of 104 +/- 1.8 omega-cm2 after 24 h. Mature monolayers were morphologically and functionally polarized. They contained junctional complexes composed of desmosomes and tight junctions with properties similar to those of 'leaky' epithelia. Monolayers were capable of maintaining a spontaneous electrical potential sensitive to amiloride, produced a net water flux from the apical to basal side, and discriminated between Na+ and Cl- ions. The MDCK permeability barrier behaves as a 'thin' membrane with negatively charged sites. It has: (a) a linear conductance/concentration relationship; (b) an asymmetric instantaneous current/voltage relationship; (c) a reduced ability to discriminate between Na+ and Cl- caused by lowering the pH; and (d) a characteristic pattern of ionic selectivity which suggests that the negatively charged sites are highly hydrates and of medium field strength. Measurements of Na+ permeability of electrical and tracer methods ruled out exchange diffusion as a mechanism for ion permeation and the lack of current saturation in the I/deltapsi curves does not support the involvement of carriers. The discrimination between Na+ and Cl- was severely but reversibly decreased at low pH, suggesting that Na+-specific channels which exclude Cl- contain acidic groups dissociated at neutral pH. Bound Ca++ ions are involved in maintaining the integrity of the junctions in MDCK monolayers as was shown by a reversible drop of resistance and opening of the junctions in Ca++-free medium containing EGTA. Several other epithelial cell lines are capable of developing a significant resistance under the conditions used to obtain MDCK monolayers
— id: 55843, year: 1978, vol: 77, page: 853, stat: Journal Article,

INVITRO SYNTHESIS OF CA2+ TRANSPORT ATPASE BY RIBOSOMES BOUND TO SARCOPLASMIC-RETICULUM MEMBRANE
Chyn, TL; Martonosi, AN; Doisy, EA; Morimoto, T; Sabatini, DD
1978 ;79(2):A365-A365, Journal of cell biology
— id: 29877, year: 1978, vol: 79, page: A365, stat: Journal Article,

RECONSTITUTION OF MICROSOMAL VESICLES CONTAINING FUNCTIONAL BINDING-SITES FOR RIBOSOMES
Czakograham, M; Sabatini, DD; Algranati, I; Bard, E; Morimoto, T; Kreibich, G
1978 ;37(6):1568-1568, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 29907, year: 1978, vol: 37, page: 1568, stat: Journal Article,

SYNTHESIS AND ASSEMBLY OF TIGHT JUNCTION COMPONENTS BY EPITHELIAL-CELLS INVITRO
Dolan, W; Griepp, EB; Robbins, ES; Sabatini, D
1978 ;79(2):A220-A220, Journal of cell biology
— id: 29872, year: 1978, vol: 79, page: A220, stat: Journal Article,

Localization of eukaryotic initiation factor 3 on native small ribosomal subunits
Emanuilov I; Sabatini DD; Lake JA; Freienstein C
1978 Mar;75(3):1389-1393, Proceedings of the National Academy of Sciences of the United States of America
— id: 55844, year: 1978, vol: 75, page: 1389, stat: Journal Article,

Characterization of the ribosomal binding site in rat liver rough microsomes: ribophorins I and II, two integral membrane proteins related to ribosome binding
Kreibich G; Czako-Graham M; Grebenau R; Mok W; Rodriguez-Boulan E; Sabatini DD
1978 ;8(3):279-302, Journal of supramolecular structure
Rat liver rough endoplasmic reticulum membranes (ER) contain two characteristic transmembrane glycoproteins which have been designated ribophorins I and II and are absent from smooth ER membranes. These proteins (MW 65,000 and 63,000 respectively) are related to the binding sites for ribosomes, as suggested by the following findings: i) The ribophorin content of the rough ER membranes corresponds stoichiometrically to the number of bound ribosomes; ii) ribophorins are quantitatively recovered with the bound polysomes after most other ER membrane proteins are dissolved with the nonionic detergent Kyro EOB; iii) in intact rough microsomes ribophorins can be cross-linked chemically to the ribosomes and therefore are in close proximity to them. Treatment of rough microsomes with a low Triton-X-100 concentration leads to the lateral displacement of ribosomes on the microsomal surface and to the formation of aggregates of bound ribosomes in areas of membranes which frequently invaginate into the microsomal lumen. Subfractionation of Triton-treated microsomes containing invaginations led to the recovery of smooth and 'rough-inverted' vesicles. Ribophorins were present only in the latter fraction, indicating that both proteins are displaced together with the ribosomes when these aggregate without detaching. Measurements of the ribosome-binding capacity of rough and smooth microsomal membranes reconstituted after solubilization with detergents suggest that ribophorins are necessary for in vitro ribosome binding. Ribophorin-like proteins were found in rough microsomes obtained from secretory tissues of several animal species. The two proteins present in rat lacrimal gland microsomes have the same mobility as hepatocyte ribophorins and cross-react with antisera against them
— id: 18452, year: 1978, vol: 8, page: 279, stat: Journal Article,

Proteins of rough microsomal membranes related to ribosome binding. II. Cross-linking of bound ribosomes to specific membrane proteins exposed at the binding sites
Kreibich G; Freienstein CM; Pereyra BN; Ulrich BL; Sabatini DD
1978 May;77(2):488-506, Journal of cell biology
Two proteins (ribophorins I and II), which are integral components of rough microsomal membranes and appear to be related to the bound ribosomes, were shown to be exposed on the surface of rat liver rough microsomes (RM) and to be in close proximity to the bound ribosomes. Both proteins were labeled when intact RM were incubated with a lactoperoxidase iodinating system, but only ribophorin I was digested during mild trypsinization of intact RM. Ribophorin II (63,000 daltons) was only proteolyzed when the luminal face of the microsomal vesicles was made accessible to trypsin by the addition of sublytical detergent concentrations. Only 30--40% of the bound ribosomes were released during trypsinization on intact RM, but ribosome release was almost complete in the presence of low detergent concentrations. Very low glutaraldehyde concentrations (0.005--0.02%) led to the preferential cross-linking of large ribosomal subunits of bound ribosomes to the microsomal membranes. This cross-linking prevented the release of subunits caused by puromycin in media of high ionic strength, but not the incorporation of [3H]puromycin into nascent polypeptide chains. SDS-acrylamide gel electrophoresis of cross-linked samples a preferential reduction in the intensity of the bands representing the ribophorins and the formation of aggregates which did not penetrate into the gels. At low methyl-4-mercaptobutyrimidate (MMB) concentrations (0.26 mg/ml) only 30% of the ribosomes were cross-linked to the microsomal membranes, as shown by the puromycin-KCl test, but membranes could still be solubilized with 1% DOC. This allowed the isolation of the ribophorins together with the sedimentable ribosomes, as was shown by electrophoresis of the sediments after disruption of the cross-links by reduction. Experiments with RM which contained only inactive ribosomes showed that the presence of nascent chains was not necessary for the reversible cross-linking of ribosomes to the membranes. These observations suggest that ribophorins are in close proximity to the bound ribosomes, as may be expected from components of the ribosome-binding sites
— id: 18451, year: 1978, vol: 77, page: 488, stat: Journal Article,

Proteins of rough microsomal membranes related to ribosome binding. I. Identification of ribophorins I and II, membrane proteins characteristics of rough microsomes
Kreibich G; Ulrich BL; Sabatini DD
1978 May;77(2):464-487, Journal of cell biology
Rat liver rough microsomes (RM) contain two integral membrane proteins which are not found in smooth microsomes (SM) and appear to be related to the presence of ribosome-binding sites. These proteins, of molecular weight 65,000 and 63,000, were designated ribophorins I and II, respectively. They were not released from the microsomal membranes by alkali or acid treatment, or when the ribosomes were detached by incubation with puromycin in a high salt medium. The anionic detergent sodium deoxycholate caused solubilization of the ribophorins, but neutral detergents led to their recovery with the sedimentable ribosomes. Ribosomal aggregates containing both ribophorins, but few other membrane proteins, were obtained from RM treated with the nonionic detergent Kyro EOB (2.5 X10(-2) M) in a low ionic strength medium. Sedimentation patterns produced by these aggregates resembled those of large polysomes but were not affected by RNase treatment. The aggregates, however, were dispersed by mild trypsinization (10 microgram trypsin for 30 min at 0 degrees C), incubation with deoxycholate, or in a medium of high salt concentration. These treatments led to a concomitant degradation or release of the ribophorins. It was estimated, from the staining intensity of protein bands in acrylamide gels, that in the Kyro EOB aggregates there were one to two molecules of each ribophorin per ribosome. Sedimentable complexes without ribosomes containing both ribophorins could also be obtained by dissolving RM previously stripped of ribosomes by puromycin-KCl using cholate, a milder detergent than DOC. Electron microscope examination of the residue obtained from RM treated with Kyro EOB showed that the rapidly sedimenting polysome-like aggregates containing the ribophorins consisted of groups of tightly packed ribosomes which were associated with remnants of the microsomal membranes
— id: 18450, year: 1978, vol: 77, page: 464, stat: Journal Article,

RECOVERY OF RIBOPHORINS IN INVERTED ROUGH VESICLES DERIVED FROM RAT-LIVER MICROSOMES
Kreibich, G; Ojakian, G; Rodriguezboulan, E; Feng, T; Sabatini, DD
1978 ;79(2):A231-A231, Journal of cell biology
— id: 29874, year: 1978, vol: 79, page: A231, stat: Journal Article,

INVITRO SYNTHESIS OF BETA-GLUCURONIDASE BY RAT-LIVER AND PREPUTIAL GLAND MEMBRANE-BOUND RIBOSOMES
Popov, D; Alterman, L; Sabatini, D; Kreibich, G
1978 ;79(2):A364-A364, Journal of cell biology
— id: 29876, year: 1978, vol: 79, page: A364, stat: Journal Article,

Spatial orientation of glycoproteins in membranes of rat liver rough microsomes. I. Localization of lectin-binding sites in microsomal membranes
Rodriguez Boulan E; Kreibich G; Sabatini DD
1978 Sep;78(3):874-893, Journal of cell biology
Carbohydrate-containing structures in rat liver rough microsomes (RM) were localized and characterized using iodinated lectins of defined specificity. Binding of [125I]Con A increased six- to sevenfold in the presence of low DOC (0.04--0.05%) which opens the vesicles and allows the penetration of the lectins. On the other hand, binding of [125I]WGA and [125I]RCA increased only slightly when the microsomal vesicles were opened by DOC. Sites available in the intact microsomal fraction had an affinity for [125I]Con A 14 times higher than sites for lectin binding which were exposed by the detergent treatment. Lectin-binding sites in RM were also localized electron microscopically with lectins covalently bound to biotin, which, in turn, were visualized after their reaction with ferritin-avidin (F-Av) markers. Using this method, it was demonstrated that in untreated RM samples, binding sites for lectins are not present on the cytoplasmic face of the microsomal vesicles, even after removal of ribosomes by treatment with high salt buffer and puromycin, but are located on smooth membranes which contaminate the rough microsomal fraction. Combining this technique with procedures which render the interior of the microsomal vesicles accessible to lectins and remove luminal proteins, it was found that RM membranes contain binding sites for Con A and for Lens culinaris agglutinin (LCA) located exclusively on the cisternal face of the membrane. No sites for WGA, RCA, soybean (SBA) and Lotus tetragonobulus (LTA) agglutinins were detected on either the cytoplasmic or the luminal faces of the rough microsomes. These observations demonstrate that: (a) sugar moieties of microsomal glycoproteins are exposed only on the luminal surface of the membranes and (b) microsomal membrane glycoproteins have incomplete carbohydrate chains without the characteristic terminal trisaccharides N-acetylglucosamine comes from galactose comes from sialic acid or fucose present in most glycoproteins secreted by the liver. The orientation and composition of the carbohydrate chains in microsomal glycoproteins indicate that the passage of these glycoproteins through the Golgi apparatus, followed by their return to the endoplasmic reticulum, is not required for their biogenesis and insertion into the endoplasmic reticulum (ER) membrane
— id: 18448, year: 1978, vol: 78, page: 874, stat: Journal Article,

Spatial orientation of glycoproteins in membranes of rat liver rough microsomes. II. Transmembrane disposition and characterization of glycoproteins
Rodriguez Boulan E; Sabatini DD; Pereyra BN; Kreibich G
1978 Sep;78(3):894-909, Journal of cell biology
Rat liver microsomal glycoproteins were purified by affinity chromatography on concanavalin A Sepharose columns from membrane and content fractions, separated from rough microsomes (RM) treated with low concentrations of deoxycholate (DOC). All periodic acid-Schiff (PAS)-positive glycoproteins of RM showed affinity for concanavalin A Sepharose; even after sodium dodecyl sulfate (SDS) acrylamide gel electrophoresis, most of the microsomal glycoproteins bound [125I]concanavalin A added to the gels, as detected by autoradiography. Two distinct sets of glycoproteins are present in the membrane and content fractions derived from RM. SDS acrylamide gel electrophoresis showed that RM membranes contain 15--20 glycoproteins (15--22% of the total microsomal protein) which range in apparent mol wt from 23,000 to 240,000 daltons. A smaller set of glycoproteins (five to seven polypeptides), with apparent mol wt between 60,000 and 200,000 daltons, was present in the microsomal content fraction. The disposition of the membrane glycoproteins with respect to the membrane plane was determined by selective iodination with the lactoperoxidase (LPO) technique. Intact RM were labeled on their outer face with 131I and, after opening of the vesicles with 0.05% DOC, in both faces with 125I. An analysis of iodination ratios for individual proteins separated electrophoretically showed that in most membrane glycoproteins, tyrosine residues are predominantly exposed on the luminal face of the vesicles, which is the same face on which the carbohydrate moieties are exposed. Several membrane glycoproteins are also exposed on the cytoplasmic surface and therefore have a transmembrane disposition. In this study, ribophorins I and II, two integral membrane proteins (mol wt 65,000 and 63,000) characteristic of RM, were found to be transmembrane glycoproteins. It is suggested that the transmembrane disposition of the ribophorins may be related to their possible role in ribosome binding and in the vectorial transfer of nascent polypeptides into the microsomal lumen
— id: 18447, year: 1978, vol: 78, page: 894, stat: Journal Article,

ASYMMETRIC PRODUCTION OF VIRUSES BY EPITHELIA
Rodriguezboulan, E; Sabatini, DD
1978 ;37(6):1772-1772, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 29808, year: 1978, vol: 37, page: 1772, stat: Journal Article,

ASYMMETRIC BUDDING OF VIRUSES INVITRO - MODEL FOR STUDYING BIOGENESIS OF EPITHELIAL POLARITY
Rodriguezboulan, EJ; Sabatini, DD
1978 ;79(2):A223-A223, Journal of cell biology
— id: 29873, year: 1978, vol: 79, page: A223, stat: Journal Article,

INVITRO FORMATION OF CELL LAYERS WITH PROPERTIES OF EPITHELIAL MEMBRANES
CEREIJIDO, M; ROTUNNO, CA; ROBBINS, ES; SABATINI, DD
1977 ;17(2):A22-A22, Biophysical journal
— id: 40016, year: 1977, vol: 17, page: A22, stat: Journal Article,

SYNTHESIS AND PROCESSING OF PRE-PROALBUMIN IN RECONSTRUCTED RAT-LIVER MICROSOMES
Gaetani, S; Smith, J; Sabatini, DD; Morimoto, T
1977 ;75(2):A359-A359, Journal of cell biology
— id: 29572, year: 1977, vol: 75, page: A359, stat: Journal Article,

IDENTIFICATION OF MEMBRANE PROTEINS (RIBOPHORINS) RELATED TO RIBOSOME BINDING IN ROUGH MICROSOMAL-MEMBRANES OF DIFFERENT ORGANS AND SPECIES
Grebenau, R; Sabatini, DD; Kreibich, G
1977 ;75(2):A234-A234, Journal of cell biology
— id: 29566, year: 1977, vol: 75, page: A234, stat: Journal Article,

2 MEMBRANE PROTEINS OF RAT-LIVER MICROSOMES RELATED TO RIBOSOME BINDING
Kreibich, G; Grebenau, R; Mok, W; Pereyra, B; Rodriguezboulan, E; Ulrich, B; Sabatini, DD
1977 ;36(3):656-656, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 29631, year: 1977, vol: 36, page: 656, stat: Journal Article,

CHARACTERIZATION OF 2 MEMBRANE PROTEINS OF RAT-LIVER ROUGH MICROSOMES INVOLVED IN RIBOSOME BINDING
Kreibich, G; Sabatini, DD
1977 ;297(2):166-166, Journal of supramolecular structure
— id: 29577, year: 1977, vol: 297, page: 166, stat: Journal Article,

Release of poly A(+) messenger RNA from rat liver rough microsomes upon disassembly of bound polysomes
Kruppa J; Sabatini DD
1977 Aug;74(2):414-427, Journal of cell biology
— id: 55847, year: 1977, vol: 74, page: 414, stat: Journal Article,

Accessibility of proteins in rat liver-free and membrane-bound ribosomes to lactoperoxidase-catalyzed iodination
Lewis JA; Sabatini DD
1977 Aug 10;252(15):5547-5555, Journal of biological chemistry
— id: 55846, year: 1977, vol: 252, page: 5547, stat: Journal Article,

Modification of two large sub-unit proteins by a factor detached from ribosomes at high ionic strength
Lewis JA; Sabatini DD
1977 Oct 4;478(3):331-349, Biochimica & biophysica acta
— id: 55845, year: 1977, vol: 478, page: 331, stat: Journal Article,

INVIVO AND INVITRO SYNTHESIS OF CYTOCHROME-P-450
Negishi, M; Sabatini, DD; Kreibich, G
1977 ;75(2):A235-A235, Journal of cell biology
— id: 29567, year: 1977, vol: 75, page: A235, stat: Journal Article,

Mobility of ribosomes bound to microsomal membranes. A freeze-etch and thin-section electron microscope study of the structure and fluidity of the rough endoplasmic reticulum
Ojakian GK; Kreibich G; Sabatini DD
1977 Mar;72(3):530-551, Journal of cell biology
The lateral mobility of ribosomes bound to rough endoplasmic reticulum (RER) membranes was demonstrated under experimental conditions. High-salt-washed rough microsomes were treated with pancreatic ribonuclease (RNase) to cleave the mRNA of bound polyribosomes and allow the movement of individual bound ribosomesmfreeze-etch and thin-section electron microscopy demonstrated that, when rough microsomes were treated with RNase at 4 degrees C and then maintained at this temperature until fixation, the bound ribosomes retained their homogeneous distribution on the microsomal surface. However, when RNase-treated rough microsomes were brought to 24 degrees C, a temperature above the thermotropic phase transition of the microsomal phospholipids, bound ribosomes were no longer distributed homogeneously but, instead, formed large, tightly packed aggregates on the microsomal surface. Bound polyribosomes could also be aggregated by treating rough microsomes with antibodies raised against large ribosomal subunit proteins. In these experiments, extensive cross-linking of ribosomes from adjacent microsomes also occurred, and large ribosome-free membrane areas were produced. Sedimentation analysis in sucrose density gradients demonstrated that the RNase treatment did not release bound ribosomes from the membranes; however, the aggregated ribosomes remain capable of peptide bond synthesis and were released by puromycin. It is proposed that the formation of ribosomal aggregates on the microsomal surface results from the lateral displacement of ribosomes along with their attached binding sites, nascent polypeptide chains, and other associated membrane proteins; The inhibition of ribosome mobility after maintaining rough microsomes at 4 degrees C after RNase, or antibody, treatment suggests that the ribosome binding sites are integral membrane proteins and that their mobility is controlled by the fluidity of the RER membrane. Examination of the hydrophobic interior of microsomal membranes by the freeze-fracture technique revealed the presence of homogeneously distributed 105-A intramembrane particles in control rough microsomes. However, aggregation of ribosomes by RNase, or their removal by treatment with puromycin, led to a redistribution of the particles into large aggregates on the cytoplasmic fracture face, leaving large particle-free regions
— id: 18453, year: 1977, vol: 72, page: 530, stat: Journal Article,

EFFECT OF A LOCAL-ANESTHETIC (DIBUCAINE) ON CELL-SHAPE AND CYTOSKELETAL ORGANIZATION IN EARLY AND LATE PASSAGE WI38 FIBROBLASTS
Ojakian, GK; Lockwood, AH; Hallarman, P; Sabatini, DD
1977 ;75(2):A294-A294, Journal of cell biology
— id: 29571, year: 1977, vol: 75, page: A294, stat: Journal Article,

LECTIN BINDING-SITES IN RAT-LIVER CELL FRACTIONS
Rodriguezboulan, E; Delemos, C; Kreibich, G; Sabatini, DD
1977 ;75(2):A235-A235, Journal of cell biology
— id: 29568, year: 1977, vol: 75, page: A235, stat: Journal Article,

Retention of mRNA on the endoplasmic reticulum membranes after in vivo disassembly of polysomes by an inhibitor of initiation
Adesnik M; Lande M; Martin T; Sabatini DD
1976 Oct;71(1):307-313, Journal of cell biology
Membrane-bound ribosomes and messenger RNA remained associated with the microsomal membranes of human fibroblasts after cultures were treated with Verrucarin A, an inhibitor of initiation which led to extensive run-off of ribosomes from polysomal structures. When a membrane fraction from Verrucarin-treated cells containing such inactive ribosomes and mRNA was suspended in a medium of high salt concentration, extensive release of ribosomal subunits occurred without the need for puromycin. The mRNA nevertheless remained associated with the membranes. These results add support to the conclusion that, in human fibroblasts, mRNA is bound directly to ER membranes, independently of the ribosomes and nascent polypeptide chains
— id: 55814, year: 1976, vol: 71, page: 307, stat: Journal Article,

STRUCTURE OF NATIVE SMALL RIBOSOMAL-SUBUNITS AND EUKARYOTIC INITIATION FACTOR-3 IN RABBIT RETICULOCYTES
Emanuilov, I; Lake, JA; Sabatini, DD; Freienstein, CM
1976 ;70(2):A297-A297, Journal of cell biology
— id: 29453, year: 1976, vol: 70, page: A297, stat: Journal Article,

Intracellular location of newly synthesized interferon in human FS-4 cells
Falcoff E; Havell EA; Lewis JA; Lande MA; Falcoff R; Sabatini DD; Vilcek J
1976 Dec;75(2):384-393, Virology
— id: 15631, year: 1976, vol: 75, page: 384, stat: Journal Article,

LARGE RIBOSOMAL-SUBUNIT PROTEIN INVOLVED IN BINDING OF RIBOSOMES TO ENDOPLASMIC-RETICULUM MEMBRANES
Lewis, JA; Sabatini, DD
1976 ;70(2):A153-A153, Journal of cell biology
— id: 29450, year: 1976, vol: 70, page: A153, stat: Journal Article,

SPECIFICITY AND CONTROL OF BINDING OF RIBOSOMES TO ENDOPLASMIC- RETICULUM MEMBRANES
Mok, W; Freienstein, C; Sabatini, D; Kreibich, G
1976 ;70(2):A393-A393, Journal of cell biology
— id: 29455, year: 1976, vol: 70, page: A393, stat: Journal Article,

DISTRIBUTION AND MOBILITY OF INTRAMEMBRANOUS PARTICLES IN ROUGH MICROSOMES
Ojakian, G; Sabatini, D
1976 ;70(2):A325-A325, Journal of cell biology
— id: 29454, year: 1976, vol: 70, page: A325, stat: Journal Article,

IMPAIRED MESSENGER-RNA BIOGENESIS IN SENESCENT HUMAN FIBROBLASTS
Hadjiolov, A; Adesnik, M; Lande, M; Sabatini, D
1975 ;67(2):A151-A151, Journal of cell biology
— id: 28625, year: 1975, vol: 67, page: A151, stat: Journal Article,

POLYPEPTIDE COMPOSITIONAL DIFFERENCES BETWEEN ROUGH AND SMOOTH MICROSOMAL-MEMBRANES
Kreibich, G; Ulrich, B; Sabatini, D
1975 ;67(2):A225-A225, Journal of cell biology
— id: 28627, year: 1975, vol: 67, page: A225, stat: Journal Article,

RELEASE OF MESSENGER-RNA FROM RAT-LIVER ROUGH MICROSOMES UPON DISASSEMBLY OF BOUND POLYSOMES
Kruppa, J; Sabatini, D
1975 ;67(2):A227-A227, Journal of cell biology
— id: 28507, year: 1975, vol: 67, page: A227, stat: Journal Article,

Direct association of messenger RNA with microsomal membranes in human diploid fibroblasts
Lande MA; Adesnik M; Sumida M; Tashiro Y; Sabatini DD
1975 Jun;65(3):513-528, Journal of cell biology
Messenger RNA (mRNA) of membrane-bound polysomes in a membrane fraction of WI-38 cells remains associated with the microsomal membranes even after ribosomes and their nascent polypeptide chains are removed by using puromycin in a high salt buffer or by disassembling the ribosomes in a medium of high ionic strength lacking magnesium. mRNA either was specifically labeled in the presence of actinomycin D, or it was recognized by virtue of its affinity for oligo-dT. Poly A segments in bound mRNAs have an electrophoretic mobility in acrylamide gels which is characteristic of cytoplasmic mRNAs and corresponds to 150-200 adenyl residues. Extensive RNase treatment did not lead to release of the poly A segments of membrane-associated mRNA molecules either from an intact membrane fraction or from a membrane fraction previously stripped of ribosomes. On the other hand, RNase treatment led to the release and digestion of the nonpoly A segments of the mRNA molecules, indicating that the site of attachment of mRNA to the ER membranes is located near or at the 3' end of the molecule which contains the poly A. A direct association of mRNAs and endoplasmic reticulum membranes is considered in a modelto explain the assembly of bound polysomes and protein synthesis in a membrane-associated apparatus
— id: 55815, year: 1975, vol: 65, page: 513, stat: Journal Article,

IDENTIFICATION OF A RIBOSOMAL-PROTEIN INVOLVED IN BINDING OF RIBOSOMES TO ROUGH MICROSOMAL-MEMBRANES
Lewis, J; Sabatini, D
1975 ;67(2):A241-A241, Journal of cell biology
— id: 28628, year: 1975, vol: 67, page: A241, stat: Journal Article,

LATERAL MOVEMENT OF RIBOSOMES ON MICROSOMAL-MEMBRANES DETECTED BY FREEZE-ETCHING
Ojakian, G; Kreibich, G; Kruppa, J; Mok, W; Sabatini, DD
1975 ;34(3):536-536, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 28673, year: 1975, vol: 34, page: 536, stat: Journal Article,

MOBILITY OF RIBOSOMES AND RIBOSOME-ASSOCIATED PARTICLES IN ROUGH MICROSOMAL-MEMBRANES
Ojakian, G; Sabatini, D
1975 ;67(2):A314-A314, Journal of cell biology
— id: 28629, year: 1975, vol: 67, page: A314, stat: Journal Article,

SPATIAL LOCATION OF GLYCOPROTEINS IN MICROSOMAL-MEMBRANES
RODRIQUEZBOULAN, ER; KREIBICH, G; SABATINI, DD
1975 ;34(3):582-582, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 98739, year: 1975, vol: 34, page: 582, stat: Journal Article,

Structural and functional aspects of the protein synthesizing apparatus in the rough endoplasmic reticulum
Sabatini DD; Ojakian G; Lande MA; Lewis J; Mok W; Adesnik M; Kreibich G
1975 ;62(3):151-180, Advances in experimental medicine & biology
— id: 18454, year: 1975, vol: 62, page: 151, stat: Journal Article,

Nondestructive separation of rat liver rough microsomes into ribosomal and membranous components
Adelman MR; Blobel G; Sabatini DD
1974 ;31(Pt A):201-215, Methods in enzymology
— id: 55848, year: 1974, vol: 31, page: 201, stat: Journal Article,

Ribosomal-membrane interaction: in vitro binding of ribosomes to microsomal membranes
Borgese N; Mok W; Kreibich G; Sabatini DD
1974 Sep 25;88(3):559-580, Journal of molecular biology
— id: 18455, year: 1974, vol: 88, page: 559, stat: Journal Article,

SYNTHESIS OF 2 SECRETORY PROTEINS DURING AGING OF HUMAN DI PLOID CELLS
FRIEDMAN E; FALCOFF E; ADESNIK M; SABATINI D
1974 ;9(5):351-352, In vitro
— id: 104658, year: 1974, vol: 9, page: 351, stat: Journal Article,

On the spatial arrangememt of proteins in microsomal membranes from rat liver
Kreibich G; Hubbard AL; Sabatini DD
1974 Mar;60(3):616-627, Journal of cell biology
— id: 18457, year: 1974, vol: 60, page: 616, stat: Journal Article,

Procedure for the selective release of content from microsomal vesicles without membrane disassembly
Kreibich G; Sabatini DD
1974 ;31(Pt A):215-225, Methods in enzymology
— id: 18458, year: 1974, vol: 31, page: 215, stat: Journal Article,

Selective release of content from microsomal vesicles without membrane disassembly. II. Electrophoretic and immunological characterization of microsomal subfractions
Kreibich G; Sabatini DD
1974 Jun;61(3):789-807, Journal of cell biology
— id: 18456, year: 1974, vol: 61, page: 789, stat: Journal Article,

DIRECT ASSOCIATION OF MESSENGER-RNA WITH MICROSOMAL-MEMBRANES IN HUMAN DIPLOID FIBROBLASTS
Lande, M; Sumida, M; Tashiro, Y; Adesnik, M; Sabatini, D
1974 ;63(2):A183-A183, Journal of cell biology
— id: 28424, year: 1974, vol: 63, page: A183, stat: Journal Article,

An improved cell fractionation procedure for the preparation of rat liver membrane-bound ribosomes
Adelman MR; Blobel G; Sabatini DD
1973 Jan;56(1):191-205, Journal of cell biology
— id: 55851, year: 1973, vol: 56, page: 191, stat: Journal Article,

Ribosome-membrane interaction. Nondestructive disassembly of rat liver rough microsomes into ribosomal and membranous components
Adelman MR; Sabatini DD; Blobel G
1973 Jan;56(1):206-229, Journal of cell biology
— id: 55850, year: 1973, vol: 56, page: 206, stat: Journal Article,

In vitro exchange of ribosomal subunits between free and membrane-bound ribosomes
Borgese D; Blobel G; Sabatini DD
1973 Mar 15;74(4):415-438, Journal of molecular biology
— id: 55849, year: 1973, vol: 74, page: 415, stat: Journal Article,

Selective release of content from microsomal vesicles without membrane disassembly. I. Permeability changes induced by low detergent concentrations
Kreibich G; Debey P; Sabatini DD
1973 Aug;58(2):436-462, Journal of cell biology
— id: 18462, year: 1973, vol: 58, page: 436, stat: Journal Article,

Microsomal membranes and the translational apparatus of eukaryotic cells
Kreibich G; Sabatini DD
1973 Nov;32(11):2133-2138, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 18461, year: 1973, vol: 32, page: 2133, stat: Journal Article,

SPATIAL ARRANGEMENT OF PROTEINS IN RAT-LIVER MICROSOMAL MEMBRANES
KREIBICH, G; HUBBART, AL; SABATINI, DD
1973 ;32(3):674-&, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 39807, year: 1973, vol: 32, page: 674, stat: Journal Article,

RIBOSOME-MEMBRANE ASSOCIATION IN RAT-LIVER ROUGH MICROSOMES
SABATINI, D; KREIBICH, G
1973 ;23(3):231-232, Acta physiologica latinoamerica
— id: 39769, year: 1973, vol: 23, page: 231, stat: Journal Article,

Ribosome crystallization in chicken embryos. I. Isolation, characterization, and in vitro activity of ribosome tetramers
Morimoto T; Blobel G; Sabatini DD
1972 Feb;52(2):338-354, Journal of cell biology
— id: 55853, year: 1972, vol: 52, page: 338, stat: Journal Article,

Ribosome crystallization in chicken embryos. II. Conditions for the formation of ribosome tetramers in vitro
Morimoto T; Blobel G; Sabatini DD
1972 Feb;52(2):355-366, Journal of cell biology
— id: 55852, year: 1972, vol: 52, page: 355, stat: Journal Article,

Ribosome-membrane interaction: Structural aspects and functional implications
Sabatini, D D; Blobel, G; Nonomura, Y; Adelman, M R
1971 May;1:119-129, Advances in cytopharmacology
— id: 55854, year: 1971, vol: 1, page: 119, stat: Journal Article,

Controlled proteolysis of nascent polypeptides in rat liver cell fractions. I. Location of the polypeptides within ribosomes
Blobel G; Sabatini DD
1970 Apr;45(1):130-145, Journal of cell biology
— id: 55856, year: 1970, vol: 45, page: 130, stat: Journal Article,

Controlled proteolysis of nascent polypeptides in rat liver cell fractions. II. Location of the polypeptides in rough microsomes
Sabatini DD; Blobel G
1970 Apr;45(1):146-157, Journal of cell biology
— id: 55855, year: 1970, vol: 45, page: 146, stat: Journal Article,

Vectorial discharge of peptides released by puromycin from attached ribosomes
Redman CM; Sabatini DD
1966 Aug;56(2):608-615, Proceedings of the National Academy of Sciences of the United States of America
— id: 55858, year: 1966, vol: 56, page: 608, stat: Journal Article,

On the attachment of ribosomes to microsomal membranes
Sabatini DD; Tashiro Y; Palade GE
1966 Aug;19(2):503-524, Journal of molecular biology
— id: 55857, year: 1966, vol: 19, page: 503, stat: Journal Article,

On the attachment of ribosomes to microbial membranes
Sabatini, David D
[S.l. : s.n.], 1966,
'Thesis (Ph.D) -- Rockefeller University, 1966'
— id: 1682, year: 1966, vol: , page: , stat: ,

ALDEHYDE FIXATION FOR MORPHOLOGICAL AND ENZYME HISTOCHEMICAL STUDIES WITH THE ELECTRON MICROSCOPE
SABATINI DD; MILLER F; BARRNETT RJ
1964 Feb;12:57-71, Journal of histochemistry & cytochemistry
— id: 55859, year: 1964, vol: 12, page: 57, stat: Journal Article,

Cytochemistry and electron microscopy. The preservation of cellular ultrastructure and enzymatic activity by aldehyde fixation
SABATINI DD; BENSCH K; BARRNETT RJ
1963 Apr;17:19-58, Journal of cell biology
— id: 55860, year: 1963, vol: 17, page: 19, stat: Journal Article,

Submicroscopic study of the pituitary action on the adrenocortex of the rat
SABATINI DD; DE ROBERTIS ED; BLEICHMAR HB
1962 Mar;70:390-406, Endocrinology
— id: 55861, year: 1962, vol: 70, page: 390, stat: Journal Article,

Ultrastructural zonation of adrenocortex in the rat
SABATINI DD; DE ROBERTIS ED
1961 Jan;9:105-119, Journal of biophysical & biochemical cytology
— id: 55862, year: 1961, vol: 9, page: 105, stat: Journal Article,

Submicroscopic analysis of the secretory process in the adrenal medulla
DE ROBERTIS ED; SABATINI DD
1960 Dec;19(Suppl 5):70-78, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 55863, year: 1960, vol: 19(Suppl 5), page: 70, stat: Journal Article,

[Distribution of sulfhydryl and disulfur groups in the neurohypophysis and hypothalamus in toads.]
LASANSKY A; SABATINI DD
1957 ;151(10):1755-1755, Comptes rendus des seances de la Societe de Biologie & des ses Filiales
— id: 55865, year: 1957, vol: 151, page: 1755, stat: Journal Article,

[Distribution of sulhydryl & disulfide groups in the neurohypophysis & hypothalamus of the toad.]
LASANSKY A; SABATINI DD
1957 Sep-Nov;33(6-8):177-182, Revista de la Sociedad Argentina de Biologia
— id: 55864, year: 1957, vol: 33, page: 177, stat: Journal Article,