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- W2158875314 endingPage "838" @default.
- W2158875314 startingPage "827" @default.
- W2158875314 abstract "ABSTRACT GTPases of the Ypt/Rab family play a key role in the regulation of vesicular transport. Their ability to cycle between the GTP- and the GDP-bound forms is thought to be crucial for their function. Conversion from the GTP- to the GDP-bound form is achieved by a weak endogenous GTPase activity, which can be stimulated by a GTPase-activating protein (GAP). Current models suggest that GTP hydrolysis and GAP activity are essential for vesicle fusion with the acceptor compartment or for timing membrane fusion. To test this idea, we inactivated the GTPase activity of Ypt1p by using the Q67L mutation, which targets a conserved residue that helps catalyze GTP hydrolysis in Ras. We demonstrate that the mutant Ypt1-Q67L protein is severely impaired in its ability to hydrolyze GTP both in the absence and in the presence of GAP and consequently is restricted mostly to the GTP-bound form. Surprisingly, a strain with ypt1-Q67L as the only YPT1 gene in the cell has no observable growth phenotypes at temperatures ranging from 14 to 37°C. In addition, these mutant cells exhibit normal rates of secretion and normal membrane morphology as determined by electron microscopy. Furthermore, the ypt1-Q67L allele does not exhibit dominant phenotypes in cell growth and secretion when overexpressed. Together, these results lead us to suggest that, contrary to current models for Ypt/Rab function, GTP hydrolysis is not essential either for Ypt1p-mediated vesicular transport or as a timer to turn off Ypt1p-mediated membrane fusion but only for recycling of Ypt1p between compartments. Finally, the ypt1-Q67L allele, like the wild type, is inhibited by dominant nucleotide-free YPT1 mutations. Such mutations are thought to exert their dominant phenotype by sequestration of the guanine nucleotide exchange factor (GNEF). These results suggest that the function of Ypt1p in vesicular transport requires not only the GTP-bound form of the protein but also the interaction of Ypt1p with its GNEF." @default.
- W2158875314 created "2016-06-24" @default.
- W2158875314 creator A5036888621 @default.
- W2158875314 creator A5055660436 @default.
- W2158875314 creator A5057801127 @default.
- W2158875314 creator A5090935596 @default.
- W2158875314 date "1998-02-01" @default.
- W2158875314 modified "2023-10-16" @default.
- W2158875314 title "GTP Hydrolysis Is Not Important for Ypt1 GTPase Function in Vesicular Transport" @default.
- W2158875314 cites W114547277 @default.
- W2158875314 cites W128583812 @default.
- W2158875314 cites W1513255990 @default.
- W2158875314 cites W1513729579 @default.
- W2158875314 cites W1515291359 @default.
- W2158875314 cites W1516081056 @default.
- W2158875314 cites W1554671555 @default.
- W2158875314 cites W1560656625 @default.
- W2158875314 cites W1575806712 @default.
- W2158875314 cites W1579998775 @default.
- W2158875314 cites W1589568489 @default.
- W2158875314 cites W1591861570 @default.
- W2158875314 cites W1593180325 @default.
- W2158875314 cites W1606338704 @default.
- W2158875314 cites W1825634690 @default.
- W2158875314 cites W1880291900 @default.
- W2158875314 cites W1887642177 @default.
- W2158875314 cites W1915765253 @default.
- W2158875314 cites W1916002325 @default.
- W2158875314 cites W1949772429 @default.
- W2158875314 cites W1965260691 @default.
- W2158875314 cites W1974654475 @default.
- W2158875314 cites W1984646224 @default.
- W2158875314 cites W1988020006 @default.
- W2158875314 cites W1992864103 @default.
- W2158875314 cites W1995235301 @default.
- W2158875314 cites W1995497833 @default.
- W2158875314 cites W1997168691 @default.
- W2158875314 cites W2000345813 @default.
- W2158875314 cites W2001482496 @default.
- W2158875314 cites W2002410732 @default.
- W2158875314 cites W2004118662 @default.
- W2158875314 cites W2005189737 @default.
- W2158875314 cites W2007741564 @default.
- W2158875314 cites W2013175327 @default.
- W2158875314 cites W2016266703 @default.
- W2158875314 cites W2016417523 @default.
- W2158875314 cites W2020358132 @default.
- W2158875314 cites W2026059959 @default.
- W2158875314 cites W2026283030 @default.
- W2158875314 cites W2034403065 @default.
- W2158875314 cites W2035962493 @default.
- W2158875314 cites W2036277985 @default.
- W2158875314 cites W2037805795 @default.
- W2158875314 cites W2038966235 @default.
- W2158875314 cites W2040792888 @default.
- W2158875314 cites W2040897146 @default.
- W2158875314 cites W2044966579 @default.
- W2158875314 cites W2045659151 @default.
- W2158875314 cites W2047137800 @default.
- W2158875314 cites W2051333710 @default.
- W2158875314 cites W2057163724 @default.
- W2158875314 cites W2058511768 @default.
- W2158875314 cites W2058580752 @default.
- W2158875314 cites W2058834594 @default.
- W2158875314 cites W2059203800 @default.
- W2158875314 cites W2059775037 @default.
- W2158875314 cites W2060045971 @default.
- W2158875314 cites W2061129160 @default.
- W2158875314 cites W2064916160 @default.
- W2158875314 cites W2069329269 @default.
- W2158875314 cites W2076926699 @default.
- W2158875314 cites W2078072259 @default.
- W2158875314 cites W2079307547 @default.
- W2158875314 cites W2081174927 @default.
- W2158875314 cites W2085871244 @default.
- W2158875314 cites W2086660631 @default.
- W2158875314 cites W2088751119 @default.
- W2158875314 cites W2089741493 @default.
- W2158875314 cites W2090486711 @default.
- W2158875314 cites W2093978361 @default.
- W2158875314 cites W2095877041 @default.
- W2158875314 cites W2105843437 @default.
- W2158875314 cites W2108053853 @default.
- W2158875314 cites W2108943672 @default.
- W2158875314 cites W2109345429 @default.
- W2158875314 cites W2109672926 @default.
- W2158875314 cites W2111817213 @default.
- W2158875314 cites W2113883578 @default.
- W2158875314 cites W2118143411 @default.
- W2158875314 cites W2119153517 @default.
- W2158875314 cites W2120322077 @default.
- W2158875314 cites W2120689665 @default.
- W2158875314 cites W2128037607 @default.
- W2158875314 cites W2132099293 @default.
- W2158875314 cites W2134183379 @default.
- W2158875314 cites W2136428115 @default.
- W2158875314 cites W2141781497 @default.
- W2158875314 cites W2142454421 @default.