Tung-Tien Sun

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Tung-Tien Sun

Professor, Department of Cell Biology;Professor, Department of Biochemistry and Molecular Pharmacology;Professor, Department of Urology;Rudolph L. Baer Professor of Dermatology, Department of Ronald O. Perelman Department of Dermatology
Cell Biology
Course Director Scientific Methods ? Survival Skills for Young Biomedical Investigators, Instr. Lctr - Cell Biology & Histology

Contact Info

450 East 29th Street
New York, NY 10016


Research Summary

Epithelial cells line the surface of various organs and are responsible for many important biological functions including secretion, absorption and protection. As the first line of defense in frequent contact with environmental carcinogens, epithelium-derived neoplasm (the carcinomas) account for over 90% of all human tumors. It is thus critically important to better understand the structure and function of epithelial cells. Our laboratory has shown earlier that keratins, a group of intermediate proteins that were thought to be uniquely associated with skin epidermis and its appendages such as hair and nail, are present in almost all epithelial cells and their neoplasm. We showed that specific basic and acidic keratins form keratin pairs that represent markers for different pathways and stages of epithelial differentiation. By studying keratin expression in corneal epithelium, we showed that corneal epithelial stem cells are not evenly distributed in the entire corneal epithelium. Rather, corneal epithelial stem cells are found to be limited to peripheral cornea in a narrow zone known as the limbus. In collaboration with Robert Lavker and George Cotsarelis, we showed that hair follicular epithelial stem cells are not located at the bottom of hair follicle in the hair root. Rather such hair follicular stem cells reside in upper follicle in the bulge area. More recently, our group discovered a group of four epithelial membrane proteins, called uroplakins, which are made by mammalian bladder urothelium as major differentiation products. We demonstrated that the four major uroplakins (UPIa, Ib, II and IIIa) form 2 heterodimeric pairs (Ia/II and Ib/IIIa) before they can exit from the ER and undergo further assembly to form a 16-nm proteins, which then assemble into hexagonally packaged 2D crystals called urothelial plaques. These plaques cover almost completely the apical surface of bladder epithelium, and are required for the bladder epithelium to form a remarkable permeability barrier. We assembled a group of investigators (the NYU Urothelial Biology Group, which is an integral part of the NYU Center of Excellence on Urological Diseases) to study, using multidisciplinary approaches, the structure, function and disease implications of uroplakins and other urothelial membrane proteins. In training graduate and postdoctoral students, we emphasize scientific methods.

Research Interests

Biochemistry of Epithelial Differentiation

Dual ligand/receptor interactions activate urothelial defenses against uropathogenic E. coli
Liu, Yan; Memet, Sylvie; Saban, Ricardo; Kong, Xiangpeng; Aprikian, Pavel; Sokurenko, Evgeni; Sun, Tung-Tien; Wu, Xue-Ru
2015-11-16; 2045-2322,Scientific reports - id: 1834512, year: 2015 Journal Article

Generation of divergent uroplakin tetraspanins and their partners during vertebrate evolution: identification of novel uroplakins
Desalle, Rob; Chicote, Javier U; Sun, Tung-Tien; Garcia-Espana, Antonio
2014-05-02; 1471-2148,BMC evolutionary biology - id: 941092, year: 2014 Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't

SNX31: A Novel Sorting Nexin Associated with the Uroplakin-Degrading Multivesicular Bodies in Terminally Differentiated Urothelial Cells
Vieira, Neide; Deng, Fang-Ming; Liang, Feng-Xia; Liao, Yi; Chang, Jennifer; Zhou, Ge; Zheng, Weiyue; Simon, Jean-Pierre; Ding, Mingxiao; Wu, Xue-Ru; Romih, Rok; Kreibich, Gert; Sun, Tung-Tien
2014-06-14; 1932-6203,PLoS one - id: 1033592, year: 2014 Journal Article

Retinoid signaling in progenitors controls specification and regeneration of the urothelium
Gandhi, Devangini; Molotkov, Andrei; Batourina, Ekatherina; Schneider, Kerry; Dan, Hanbin; Reiley, Maia; Laufer, Ed; Metzger, Daniel; Liang, Fengxia; Liao, Yi; Sun, Tung-Tien; Aronow, Bruce; Rosen, Roni; Mauney, Josh; Adam, Rosalyn; Rosselot, Carolina; Van Batavia, Jason; McMahon, Andrew; McMahon, Jill; Guo, Jin-Jin; Mendelsohn, Cathy
2013-10-01; 1534-5807,Developmental cell - id: 549622, year: 2013 Journal Article

MAL facilitates the incorporation of exocytic uroplakin-delivering vesicles into the apical membrane of urothelial umbrella cells
Zhou, G; Liang, FX; Romih, R; Wang, Z; Liao, Y; Ghiso, J; Luque-Garcia, JL; Neubert, TA; Kreibich, G; Alonso, MA; Schaeren-Wiemers, N; Sun, TT
2012-04-26; 1059-1524,Molecular biology of the cell - id: 165440, year: 2012 JOURNAL ARTICLE