title: Interaction between the Saccharomyces cerevisiae CDC25 gene product and mammalian ras.
abstract: In order to characterize the interaction between the Saccharomyces cerevisiae Cdc25 protein and Harvey-ras (p21H-ras), we have constructed a yeast strain disrupted at the RAS1 and RAS2 loci, expressing both p21H-ras and the catalytic domain of the bovine GTPase activating protein (GAP) and containing the cdc25-2 mutation. Such a strain exhibits a temperature-sensitive phenotype. The shift to the nonpermissive temperature is accompanied by the loss of guanyl nucleotide-dependent activity of adenylylcyclase in vitro. The temperature-sensitive phenotype can be rescued by CDC25 itself, as well as by a plasmid containing a truncated SDC25 gene. In addition, wild type CDC25 significantly improves the guanyl nucleotide response observed in the background of the cdc25ts allele at the permissive temperature in a dosage-dependent manner and restores the guanyl nucleotide response at the restrictive temperature. Both CDC25 and a truncated SDC25 also restored p21H-ras-dependent guanyl nucleotide response in a strain isogenic to the one described above but containing a disrupted CDC25 locus instead of the temperature-sensitive allele. These results suggest that the S. cerevisiae Cdc25 protein interacts with p21H-ras expressed in yeast by promoting GDP-GTP exchange. It follows that the yeast system can be used for characterizing the interaction between guanyl nucleotide exchangers of Ras proteins and mammalian p21H-ras.
authors.affiliation: Department of Biological Chemistry, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Segal
authors.forename: I
authors.initials: I
authors.lastname: Marbach
authors.forename: D
authors.initials: D
authors.lastname: Engelberg
authors.forename: G
authors.initials: G
authors.lastname: Simchen
authors.forename: A
authors.initials: A
authors.lastname: Levitzki
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D018797:Cell Cycle Proteins; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D005800:Genes, Fungal; D011905:Genes, ras; D005838:Genotype; D007700:Kinetics; D008322:Mammals; D010957:Plasmids; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D018631:ras Proteins; D020666:ras-GRF1
chemical_list: C542351:CDC25 protein, S cerevisiae; D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D020666:ras-GRF1; D016283:Proto-Oncogene Proteins p21(ras); C489014:RAS1 protein, S cerevisiae; C489015:RAS2 protein, S cerevisiae; D018631:ras Proteins; D000262:Adenylyl Cyclases