title: Rab10 regulates membrane transport through early endosomes of polarized Madin-Darby canine kidney cells.
abstract: 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.
authors.affiliation: Department of Medicine, Division of Nephrology, Indiana University Medical Center, Indianapolis, IN 46202, USA.
authors.forename: Clifford M
authors.initials: CM
authors.lastname: Babbey
authors.forename: Nahid
authors.initials: N
authors.lastname: Ahktar
authors.forename: Exing
authors.initials: E
authors.lastname: Wang
authors.forename: Carlos Chih-Hsiung
authors.initials: CC
authors.lastname: Chen
authors.forename: Barth D
authors.initials: BD
authors.lastname: Grant
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Dunn
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D016764:Cell Polarity; D004285:Dogs; D011992:Endosomes / Q000737:chemistry / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006160:Guanosine Triphosphate / Q000378:metabolism; D006868:Hydrolysis; D007070:Immunoglobulin A / Q000378:metabolism; D007425:Intracellular Membranes / Q000737:chemistry / Q000378:metabolism; D007668:Kidney / Q000378:metabolism / Q000648:ultrastructure; D018613:Microscopy, Confocal; D009154:Mutation; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D022161:Transport Vesicles / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D021601:trans-Golgi Network / Q000737:chemistry / Q000378:metabolism; D000099193:rab11 GTP-Binding Proteins
chemical_list: D049452:Green Fluorescent Proteins; D006160:Guanosine Triphosphate; D007070:Immunoglobulin A; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins