RhoB-Dependent modulation of postendocytic traffic in polarized madin-darby canine kidney cells
RhoB-Dependent modulation of postendocytic traffic in polarized madin-darby canine kidney cells
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DOI：
10.1111/j.1600-0854.2007.00575.x
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发表时间：
2007-07-01
期刊：
影响因子：
4.5
通讯作者：
Apodaca, Gerard
中科院分区：
文献类型：
--
作者：
Rondanino, Christine;Rojas, Raul;Apodaca, Gerard
gtpase的Rho家族与许多细胞类型的内吞和生物合成运输的控制有关；然而，RhoB的细胞分布仍然存在争议，其功能也没有得到很好的理解。使用共聚焦显微镜，我们发现内源性RhoB和绿色荧光蛋白标记的野生型RhoB定位于固定或活极化的Madin-Darby犬肾细胞的早期核内体，并且在较小程度上定位于循环核内体，晚期核内体或高尔基复合体。与RhoB定位于早期核内体一致，我们观察到显性阴性RhoBN19或显性活性RhoBV14的表达改变了配体-受体复合物的内胞后转运，这些复合物经过循环、降解或转胞作用。体外实验证实RhoB通过调节货物从基底外侧早期核内体的出口来调节基底外侧到根尖的胞切途径。我们的研究结果表明RhoB部分定位于早期核内体，在那里它通过早期内吞系统调节受体的分泌。
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.