The small GTPase rab5 functions as a regulatory factor in the early endocytic pathway
Open Access
- 1 September 1992
- journal article
- Published by Elsevier BV in Cell
- Vol. 70 (5), 715-728
- https://doi.org/10.1016/0092-8674(92)90306-w
Abstract
We have investigated the in vivo functional role of rab5, a small GTPase associated with the plasma membrane and early endosomes. Wild-type rab5 or rab5-ile133, a mutant protein defective in GTP binding, was overexpressed in baby hamster kidney cells. In cells expressing the rab5ile 133 protein, the rate of endocytosis was decreased by 50% compared with normal, while the rate of recycling was not significantly affected. The morphology of early endosomes was also drastically changed by the mutant protein, which induced accumulation of small tubules and vesicles at the periphery of the cell. Surprisingly, overexpression of wild-type rab5 accelerated the uptake of endocytic markers and led to the appearance of atypically large early endosomes. We conclude that rab5 is a rate-limiting component of the machinery regulating the kinetics of membrane traffic in the early endocytic pathway.Keywords
This publication has 60 references indexed in Scilit:
- ADP-Ribosylation factor is a subunit of the coat of Golgi-derived COP-coated vesicles: A novel role for a GTP-binding proteinCell, 1991
- Stage-specific assays for coated pit formation and coated vesicle budding in vitro.The Journal of cell biology, 1991
- Reconstitution of GTP-binding Sar1 protein function in ER to Golgi transport.The Journal of cell biology, 1991
- The GTPase superfamily: conserved structure and molecular mechanismNature, 1991
- Microtubule- and motor-dependent fusion in vitro between apical and basolateral endocytic vesicles from MDCK cellsCell, 1990
- Structure of vaccinia virus early promotersJournal of Molecular Biology, 1989
- Vesicle fusion following receptor-mediated endocytosis requires a protein active in Golgi transportNature, 1989
- A GTP-binding protein required for secretion rapidly associates with secretory vesicles and the plasma membrane in yeastCell, 1988
- Assembled and unassembled pools of clathrin: a quantitative study using an enzyme immunoassay.The Journal of cell biology, 1985
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976