title: GPA1Val-50 mutation in the mating-factor signaling pathway in Saccharomyces cerevisiae.
abstract: The GPA1 gene of Saccharomyces cerevisiae encodes a protein that is highly homologous to the alpha subunit of mammalian hetrotrimeric G proteins and is essential for haploid cell growth. A mutation of the GPA1 protein, GPA1Val-50, in which Gly-50 was replaced by valine, could complement the growth defect of a GPA1 disruption, gpal::HIS3. However, cells with gpa1::HIS3 expressing the GPA1Val-50 protein were supersensitive to alpha-factor in a short-term incubation but resumed growth after long-term incubation even after exposure to high concentrations of alpha-factor. The former phenotype associated with GPA1Val-50 is recessive, and the latter phenotype is dominant to GPA1+. The supersensitivity of GPA1Val-50 to alpha-factor was dependent on STE2 and STE4, which demonstrates that this GPA1Val-50-produced phenotype requires the mating-factor receptor and the beta subunit of the G protein. The double mutant of sst2-1 GPA1Val-50 recovered from division arrest, which suggested that SST2 is not required for recovery of the GPA1Val-50 mutant.
authors.affiliation: Department of Molecular Biology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, California 94304.
authors.forename: I
authors.initials: I
authors.lastname: Miyajima
authors.forename: K
authors.initials: K
authors.lastname: Arai
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D000595:Amino Acid Sequence; D002455:Cell Division; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000502:physiology; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D005998:Glycine / Q000502:physiology*; D000072235:Mating Factor; D008969:Molecular Sequence Data; D009154:Mutation; D010455:Peptides / Q000502:physiology; D010641:Phenotype; D010957:Plasmids; D011956:Receptors, Cell Surface / Q000502:physiology; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D015398:Signal Transduction; D014157:Transcription Factors; D014633:Valine / Q000502:physiology; D001616:beta-Galactosidase / Q000235:genetics
chemical_list: D010455:Peptides; D011956:Receptors, Cell Surface; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide; D014157:Transcription Factors; D000072235:Mating Factor; D001616:beta-Galactosidase; D019204:GTP-Binding Proteins; D014633:Valine; D005998:Glycine