title: Association of the yeast pheromone response G protein beta gamma subunits with the MAP kinase scaffold Ste5p.
abstract: The mating response pathway of the yeast Saccharomyces cerevisiae includes a heterotrimeric guanine nucleotide-binding protein (G protein) that activates a mitogen-activated protein MAP kinase cascade by an unknown mechanism. An amino-terminal fragment of the MAP kinase scaffold protein Ste5p that interfered with pheromone-induced cell cycle arrest was identified. A haploid-specific interaction between the amino terminus of Ste5p and the G protein beta subunit Ste4p was also detected in a two-hybrid assay, and the product of a signaling-defective allele of STE4 was defective in this interaction. In cells with a constitutively activated pheromone response pathway, epitope-tagged Ste4p was coimmunoprecipitated with Ste5p. Thus, association of the G protein and the MAP kinase cassette via the scaffolding protein Ste5p may transmit the G protein signal.
authors.affiliation: Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec.
authors.forename: M S
authors.initials: MS
authors.lastname: Whiteway
authors.forename: C
authors.initials: C
authors.lastname: Wu
authors.forename: T
authors.initials: T
authors.lastname: Leeuw
authors.forename: K
authors.initials: K
authors.lastname: Clark
authors.forename: A
authors.initials: A
authors.lastname: Fourest-Lieuvin
authors.forename: D Y
authors.initials: DY
authors.lastname: Thomas
authors.forename: E
authors.initials: E
authors.lastname: Leberer
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D001483:Base Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002352:Carrier Proteins; D002455:Cell Division; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020962:Heterotrimeric GTP-Binding Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D010675:Pheromones / Q000494:pharmacology; D010957:Plasmids; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction; D014170:Transformation, Genetic
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D005656:Fungal Proteins; D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D010675:Pheromones; C084294:STE18 protein, S cerevisiae; C080321:STE5 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C067576:Ste4 protein, S cerevisiae; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019204:GTP-Binding Proteins; D020962:Heterotrimeric GTP-Binding Proteins