Msb4p, a protein involved in Cdc42p-dependent organization of the actin cytoskeleton, is a Ypt/Rab-specific GAP.
Ypt/Rab proteins of the Ras superfamily are regulators of protein transport in exo- and endocytosis. Like Ras and Rho proteins, they have a slow intrinsic GTPase activity that can be accelerated by several orders of magnitude by GTPase-activating proteins (GAP). Here we describe a new member of a family of Ypt/Rab-specific GAPs, Msb4p/Gyp4p, that shares with other Gyp family members significant homology in the catalytic domain, recently identified in Gyp1p and Gyp7p. Purified Msb4p/Gyp4p acts primarily on Sec4p, Ypt6p and Ypt7p and might have a role in polarized secretion.
Albert
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Department of Molecular Genetics, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.
Gallwitz
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D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003599:Cytoskeleton / Q000378:metabolism*; D017931:DNA Primers; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020690:GTPase-Activating Proteins / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae / Q000378:metabolism*; D020691:rab GTP-Binding Proteins / Q000378:metabolism*
D000199:Actins; D017931:DNA Primers; D005656:Fungal Proteins; D020690:GTPase-Activating Proteins; D047908:Intracellular Signaling Peptides and Proteins; C076360:MSB2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae; D020691:rab GTP-Binding Proteins