title: Constitutive activation of the Saccharomyces cerevisiae transcriptional regulator Ste12p by mutations at the amino-terminus.
abstract: The transcriptional activator Ste12p is required for the expression of genes induced by mating pheromone in the yeast Saccharomyces cerevisiae. We identified mutations in the amino-terminal DNA-binding domain of Ste12p that lead to constitutively high-level transcription of pheromone-induced genes. The behaviour of these mutant proteins is consistent with an enhanced DNA-binding ability. Cells carrying these hyperactive proteins retain their sensitivity to pheromone treatment, and their phenotype is largely dependent on the presence of at least one of the MAP kinases (Fus3p or Kss1p) and the scaffold protein Ste5p. Deletion of either FUS3 or KSS1 leads to a marked increase in Ste12p activity, consistent with a negative regulatory role for Fus3p, similar to that described for Kss1p. The properties of the constitutive mutants support the idea that the pheromone response pathway plays a role in basal as well as pheromone-induced transcription.
authors.affiliation: Program in Biochemistry and Molecular Biology, Department of Molecular and Cellular Biology, State University of New York at Stony Brook, 11794, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Crosby
authors.forename: J B
authors.initials: JB
authors.lastname: Konopka
authors.forename: S
authors.initials: S
authors.lastname: Fields
mesh_terms: D015153:Blotting, Western; D017931:DNA Primers / Q000737:chemistry; D004271:DNA, Fungal / Q000737:chemistry; D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000235:genetics / Q000502:physiology; D016296:Mutagenesis; D009154:Mutation; D016133:Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D001616:beta-Galactosidase / Q000032:analysis
chemical_list: D017931:DNA Primers; D004271:DNA, Fungal; D005656:Fungal Proteins; C489241:STE12 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D001616:beta-Galactosidase