Pheromone-induced phosphorylation of a G protein beta subunit in S. cerevisiae is associated with an adaptive response to mating pheromone.
The mating pheromone response in S. cerevisiae is activated by a G protein-mediated signaling pathway in which G beta gamma is the active transducer of the signal. When exogenous pheromone is added to vegetatively growing cells, G beta is rapidly phosphorylated at several sites; phosphorylation does not require de novo protein synthesis. A mutation in G beta was constructed that eliminates signal-induced phosphorylation. This mutation leads to enhanced sensitivity to and impaired ability to recover from pheromone, but does not affect the ability of G beta gamma to transmit the mating signal. These phenotypes suggest that G protein phosphorylation mediates an adaptive response to pheromone-induced signaling. G beta phosphorylation does not require either the pheromone receptor C-terminus or the product of the SST2 gene, both of which mediate separate adaptive responses to pheromone. However, G beta phosphorylation is greatly facilitated by the presence of the G alpha subunit, which has also been shown to participate in an adaptation to pheromone.
Cole
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GM
Molecular Biology Department, Research Institute of Scripps Clinic, La Jolla, California 92037.
Reed
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D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002872:Chromosome Deletion; D003433:Crosses, Genetic; D044387:GTP-Binding Protein beta Subunits; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005800:Genes, Fungal; D005838:Genotype; D020962:Heterotrimeric GTP-Binding Proteins; D046911:Macromolecular Substances; D000072235:Mating Factor; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism*; D010675:Pheromones / Q000494:pharmacology*; D010750:Phosphoproteins / Q000302:isolation & purification; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction; D014158:Transcription, Genetic
D000596:Amino Acids; D044387:GTP-Binding Protein beta Subunits; D046911:Macromolecular Substances; D010455:Peptides; D010675:Pheromones; D010750:Phosphoproteins; D029701:Saccharomyces cerevisiae Proteins; C067576:Ste4 protein, S cerevisiae; D000072235:Mating Factor; D019204:GTP-Binding Proteins; D020962:Heterotrimeric GTP-Binding Proteins