title: AFR1 acts in conjunction with the alpha-factor receptor to promote morphogenesis and adaptation.
abstract: Mating pheromone receptors activate a G-protein signaling pathway that induces changes in transcription, cell division, and morphogenesis needed for the conjunction of Saccharomyces cerevisiae. The C terminus of the alpha-factor pheromone receptor functions in two complex processes, adaptation and morphogenesis. Adaptation to alpha-factor may occur through receptor desensitization, and alpha-factor-induced morphogenesis forms the conjugation bridge between mating cells. A plasmid overexpression strategy was used to isolate a new gene, AFR1, which acts together with the receptor C terminus to promote adaptation. The expression of AFR1 was highly induced by alpha-factor. Unexpectedly, cells lacking AFR1 showed a defect in alpha-factor-stimulated morphogenesis that was similar to the morphogenesis defect observed in cells producing C-terminally truncated alpha-factor receptors. In contrast, AFR1 overexpression resulted in longer projections of morphogenesis, which suggests that this gene may directly stimulate morphogenesis. These results indicate that AFR1 encodes a developmentally regulated function that coordinates both the regulation of receptor signaling and the induction of morphogenesis during conjugation.
authors.affiliation: Department of Microbiology, State University of New York at Stony Brook 11794-5222.
authors.forename: J B
authors.initials: JB
authors.lastname: Konopka
mesh_terms: D000064:Acclimatization; D000595:Amino Acid Sequence; D001483:Base Sequence; D002455:Cell Division; D004271:DNA, Fungal / Q000032:analysis / Q000235:genetics; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005800:Genes, Fungal; D005838:Genotype; D007700:Kinetics; D000072235:Mating Factor; D008969:Molecular Sequence Data; D009024:Morphogenesis; D010455:Peptides / Q000494:pharmacology; D010675:Pheromones / Q000494:pharmacology; D010957:Plasmids; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide / Q000378:metabolism*; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction; D014157:Transcription Factors; D014158:Transcription, Genetic
chemical_list: C083723:AFR1 protein, S cerevisiae; D004271:DNA, Fungal; D005656:Fungal Proteins; D010455:Peptides; D010675:Pheromones; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000072235:Mating Factor; D019204:GTP-Binding Proteins