title: Saccharomyces cerevisiae GTPase complex: Gtr1p-Gtr2p regulates cell-proliferation through Saccharomyces cerevisiae Ran-binding protein, Yrb2p.
abstract: A Gtr1p GTPase, the GDP mutant of which suppresses both temperature-sensitive mutants of Saccharomyces cerevisiae RanGEF/Prp20p and RanGAP/Rna1p, was presently found to interact with Yrb2p, the S. cerevisiae homologue of mammalian Ran-binding protein 3. Gtr1p bound the Ran-binding domain of Yrb2p. In contrast, Gtr2p, a partner of Gtr1p, did not bind Yrb2p, although it bound Gtr1p. A triple mutant: yrb2delta gtr1delta gtr2delta was lethal, while a double mutant: gtr1delta gtr2delta survived well, indicating that Yrb2p protected cells from the killing effect of gtr1delta gtr2delta. Recombinant Gtr1p and Gtr2p were purified as a complex from Escherichia coli. The resulting Gtr1p-Gtr2p complex was comprised of an equal amount of Gtr1p and Gtr2p, which inhibited the Rna1p/Yrb2 dependent RanGAP activity. Thus, the Gtr1p-Gtr2p cycle was suggested to regulate the Ran cycle through Yrb2p.
authors.affiliation: Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Wang
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Nakashima
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sekiguchi
authors.forename: Takeharu
authors.initials: T
authors.lastname: Nishimoto
mesh_terms: D049109:Cell Proliferation; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020690:GTPase-Activating Proteins; D046911:Macromolecular Substances / Q000378:metabolism; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D025941:Protein Interaction Mapping; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D020931:ran GTP-Binding Protein / Q000737:chemistry / Q000378:metabolism*
chemical_list: D020690:GTPase-Activating Proteins; C121263:GTR2 protein, S cerevisiae; C121262:Gtr1 protein, S cerevisiae; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; C113422:YRB2 protein, S cerevisiae; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D020559:Monomeric GTP-Binding Proteins; D020931:ran GTP-Binding Protein