Association of the yeast pheromone response G protein beta gamma subunits with the MAP kinase scaffold Ste5p.
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.
Whiteway
M S
MS
Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec.
Wu
C
C
Leeuw
T
T
Clark
K
K
Fourest-Lieuvin
A
A
Thomas
D Y
DY
Leberer
E
E
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
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