Babbey Clifford M, Ahktar Nahid, Wang Exing, Chen Carlos Chih-Hsiung, Grant Barth D, Dunn Kenneth W
Department of Medicine, Division of Nephrology, Indiana University Medical Center, Indianapolis, IN 46202, USA.
Mol Biol Cell. 2006 Jul;17(7):3156-75. doi: 10.1091/mbc.e05-08-0799. Epub 2006 Apr 26.
Rab10, a protein originally isolated from Madin-Darby Canine Kidney (MDCK) epithelial cells, belongs to a family of Rab proteins that includes Rab8 and Rab13. Although both Rab8 and Rab13 have been found to mediate polarized membrane transport, the function of Rab10 in mammalian cells has not yet been established. We have used quantitative confocal microscopy of polarized MDCK cells expressing GFP chimeras of wild-type and mutant forms of Rab10 to analyze the function of Rab10 in polarized cells. These studies demonstrate that Rab10 is specifically associated with the common endosomes of MDCK cells, accessible to endocytic probes internalized from either the apical or basolateral plasma membrane domains. Expression of mutant Rab10 defective for either GTP hydrolysis or GTP binding increased recycling from early compartments on the basolateral endocytic pathway without affecting recycling from later compartments or the apical recycling pathway. These results suggest that Rab10 mediates transport from basolateral sorting endosomes to common endosomes.
Rab10是一种最初从犬肾上皮细胞（MDCK）中分离出来的蛋白质，属于Rab蛋白家族，该家族还包括Rab8和Rab13。尽管已发现Rab8和Rab13均介导极化膜运输，但Rab10在哺乳动物细胞中的功能尚未明确。我们利用表达野生型和突变型Rab10的绿色荧光蛋白嵌合体的极化MDCK细胞进行定量共聚焦显微镜观察，以分析Rab10在极化细胞中的功能。这些研究表明，Rab10与MDCK细胞的共同内体特异性相关，可被从顶端或基底外侧质膜结构域内化的内吞探针所接触。对GTP水解或GTP结合有缺陷的突变型Rab10的表达增加了基底外侧内吞途径早期区室的再循环，而不影响后期区室或顶端再循环途径的再循环。这些结果表明，Rab10介导从基底外侧分拣内体到共同内体的运输。
