Identification and partial purification of GTPase-activating proteins from yeast and mammalian cells that preferentially act on Ypt1/Rab1 proteins.
Two GTPase-activating proteins of apparent molecular mass of 100 kDa and 30 kDa have been partially purified from porcine liver cytosol using mammalian Ypt1/Rab1 protein as substrate. Both proteins act most efficiently on Ypt1/Rab1p, but are inactive with H-Ras p21. From the budding yeast Saccharomyces cerevisiae, a cytosolic 40 kDa yptGAP was partially purified. It accelerates the intrinsic GTPase activity of wild-type Ypt1p but not of H-Ras p21 or a mutant ypt1p with an amino acid substitution of the effector domain which renders the protein functionally inactive in yeast cells.
Department of Molecular Genetics, Max Planck Institute of Biophysical Chemistry, Göttingen, Germany.
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TJ
Tan
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Vollmer
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Gallwitz
D000818:Animals; D003600:Cytosol / Q000201:enzymology; D005656:Fungal Proteins / Q000737:chemistry / Q000302:isolation & purification*; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification*; D020690:GTPase-Activating Proteins; D008099:Liver / Q000201:enzymology; D051379:Mice; D008970:Molecular Weight; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins; D013379:Substrate Specificity; D013552:Swine; D020691:rab GTP-Binding Proteins; D020703:ras GTPase-Activating Proteins
D005656:Fungal Proteins; D020690:GTPase-Activating Proteins; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D020703:ras GTPase-Activating Proteins; D019204:GTP-Binding Proteins; C060755:YPT1 protein, S cerevisiae; D020691:rab GTP-Binding Proteins