title: Genetic evidence for a functional interaction between Saccharomyces cerevisiae CDC24 and CDC42.
abstract: Cdc24p and Cdc42p are involved in the control of cell polarity during the Saccharomyces cerevisiae cell cycle. Cdc42p is a member of the Ras superfamily of GTPases and Cdc24p displays limited amino-acid sequence similarity with the Dbl proto-oncoprotein, which acts to stimulate guanine-nucleotide exchange on human Cdc42p. We have performed several genetic experiments to test whether Cdc24p and Cdc42p interact within the cell. First, overexpression of Cdc24p suppressed the dominant-negative cdc42D118A allele. Second, overexpression of wild-type CDC24 and CDC42 genes together was a lethal event resulting in a morphological phenotype of large, round, unbudded cells, indicating a loss of cell polarity. Third, a cdc24ts cdc42ts double mutant exhibited a synthetic-lethal phenotype at the semi-permissive temperature of 30 degrees C. These data suggest that Cdc24p and Cdc42p interact within the cell and that Cdc24p may be involved in the regulation of Cdc42p activity.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Vermont, Burlington 05401.
authors.forename: M
authors.initials: M
authors.lastname: Ziman
authors.forename: D I
authors.initials: DI
authors.lastname: Johnson
mesh_terms: D000483:Alleles; D001483:Base Sequence; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D016764:Cell Polarity / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005800:Genes, Fungal; D005804:Genes, Lethal; D020662:Guanine Nucleotide Exchange Factors; D006160:Guanosine Triphosphate / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D005810:Multigene Family; D010641:Phenotype; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae; D018631:ras Proteins
chemical_list: C073594:CDC24 protein, S cerevisiae; D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D020662:Guanine Nucleotide Exchange Factors; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae; D018631:ras Proteins