Organization of uroplakin subunits: transmembrane topology, pair formation and plaque composition

被引:90
作者
Liang, FX
Riedel, I
Deng, FM
Zhou, G
Xu, C
Wu, XR
Kong, XP
Moll, R
Sun, TT [1 ]
机构
[1] NYU, Sch Med, Ronald O Perelmen Dept Dermatol, Epithelial Biol Unit, New York, NY 10016 USA
[2] Univ Marburg, Dept Pathol, D-35033 Marburg, Germany
[3] NYU, Sch Med, Skirball Inst Biomol Med, New York, NY 10016 USA
[4] NYU, Sch Med, Kaplan Comprehens Canc Ctr, Dept Urol, New York, NY 10016 USA
[5] NYU, Sch Med, Kaplan Comprehens Canc Ctr, Dept Biochem, New York, NY 10016 USA
[6] NYU, Sch Med, Kaplan Comprehens Canc Ctr, Dept Pharmacol, New York, NY 10016 USA
关键词
bladder epithelium; differentiation; tetraspanin; urothelium;
D O I
10.1042/0264-6021:3550013
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The apical surfaces of urothelial cells are almost entirely covered with plaques consisting of crystalline, hexagonal arrays of 16 nm uroplakin particles. Although all four uroplakins, when SDS-denatured, can be digested by chymotrypsin, most uroplakin domains in native urothelial plaques are resistant to the enzyme. suggesting a tightly packed structure. The only exception is the C-terminal, cytoplasmic tail of UPIII (UPIII) which is highly susceptible to proteolysis, suggesting a loose configuration. When uroplakins are solubilized with 2 degrees (degrees) octylglucoside and fractionated with ion exchangers, UPIa and UPII were bound as a complex by a cation exchanger. whereas UPIb and UPIII were bound by an anion exchanger. This result is consistent with the fact that UPIa and UPIb are cross-linked to UPII and UPIII, respectively, and suggests that the four uroplakins form two pairs consisting of UPIa/II and UPIb/III. Immunogold labelling using a new mouse monoclonal antibody, AU1, revealed that UPIII is present in all urothelial plaques. indicating that the two uroplakin pairs are not segregated into two different types of urothelial plaque and that all plaques must have a similar uroplakin composition. Taken together, these results indicate that uroplakins form a tightly packed structure, that the four uroplakins interact specifically forming two pairs, and that both uroplakin pairs are required for normal urothelial plaque formation.
引用
收藏
页码:13 / 18
页数:6
相关论文
共 35 条
[31]  
WU XR, 1995, J BIOL CHEM, V270, P29752
[32]  
WU XR, 1994, J BIOL CHEM, V269, P13716
[33]  
WU XR, 1990, J BIOL CHEM, V265, P19170
[34]   UROPLAKIN .1. A 27-KD PROTEIN ASSOCIATED WITH THE ASYMMETRIC UNIT MEMBRANE OF MAMMALIAN UROTHELIUM [J].
YU, J ;
MANABE, M ;
WU, XR ;
XU, C ;
SURYA, B ;
SUN, TT .
JOURNAL OF CELL BIOLOGY, 1990, 111 (03) :1207-1216
[35]   UROPLAKIN-IA AND UROPLAKIN-IB, 2 MAJOR DIFFERENTIATION PRODUCTS OF BLADDER EPITHELIUM, BELONG TO A FAMILY OF 4 TRANSMEMBRANE DOMAIN (4TM) PROTEINS [J].
YU, J ;
LIN, JH ;
WU, XR ;
SUN, TT .
JOURNAL OF CELL BIOLOGY, 1994, 125 (01) :171-182