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RhoB‐Dependent Modulation of Postendocytic Traffic in Polarized Madin‐Darby Canine Kidney Cells
Author(s) -
Rondanino Christine,
Rojas Raul,
Ruiz Wily G.,
Wang Exing,
Hughey Rebecca P.,
Dunn Kenneth W.,
Apodaca Gerard
Publication year - 2007
Publication title -
traffic
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.677
H-Index - 130
eISSN - 1600-0854
pISSN - 1398-9219
DOI - 10.1111/j.1600-0854.2007.00575.x
Subject(s) - endosome , rhob , endocytic cycle , microbiology and biotechnology , transcytosis , biology , endocytosis , receptor , signal transduction , biochemistry , intracellular , rhoa
The Rho family of GTPases is implicated in the control of endocytic and biosynthetic traffic of many cell types; however, the cellular distribution of RhoB remains controversial and its function is not well understood. Using confocal microscopy, we found that endogenous RhoB and green fluorescent protein‐tagged wild‐type RhoB were localized to early endosomes, and to a much lesser extent to recycling endosomes, late endosomes or Golgi complex of fixed or live polarized Madin‐Darby canine kidney cells. Consistent with RhoB localization to early endosomes, we observed that expression of dominant‐negative RhoBN19 or dominant‐active RhoBV14 altered postendocytic traffic of ligand‐receptor complexes that undergo recycling, degradation or transcytosis. In vitro assays established that RhoB modulated the basolateral‐to‐apical transcytotic pathway by regulating cargo exit from basolateral early endosomes. Our results indicate that RhoB is localized, in part, to early endosomes where it regulates receptor egress through the early endocytic system.