title: GPA1, a haploid-specific essential gene, encodes a yeast homolog of mammalian G protein which may be involved in mating factor signal transduction.
abstract: GPA1 protein of Saccharomyces cerevisiae is homologous to the alpha subunit of mammalian G protein. GPA1 transcript was found in haploid cells but was not detected in diploid cells. Disruption of GPA1 resulted in a haploid-specific lethal phenotype, indicating that GPA1 is a haploid-specific essential gene for cell growth. Upon regulation of expression of GPA1 by the galactose-inducible GAL1 promoter, the loss of GPA1 function was found to lead to cell-cycle arrest at the late G1 phase. Mutants that suppress the lethality of the gpa1::HIS3 mutation showed a sterile phenotype that was not cell-type-specific. These results suggest that GPA1 protein may control the signal for mating-factor-mediated cell-cycle arrest.
mesh_terms: D002453:Cell Cycle; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000502:physiology; D005796:Genes; D005800:Genes, Fungal; D000072235:Mating Factor; D010455:Peptides / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D010455:Peptides; D000072235:Mating Factor; D019204:GTP-Binding Proteins