Molecular characterization of SIG1, a Saccharomyces cerevisiae gene involved in negative regulation of G-protein-mediated signal transduction.
AUTOR(ES)
Leberer, E
RESUMO
Two recessive mutations in the Saccharomyces cerevisiae SIG1 (suppressor of inhibitory G-protein) gene have been identified by their ability to suppress the signalling defect of dominant-negative variants of the mating response G-protein beta-subunit. The mutations and deletion of SIG1 enhance the sensitivity of the cells to pheromone and stimulate the basal transcription of a mating specific gene, FUS1, suggesting that Sig1p plays a negatively regulatory role in G beta gamma-mediated signal transduction. An additional function of Sig1p in vegetatively growing cells is suggested by the finding that the mutations and deletion of SIG1 cause temperature-sensitive growth defects. The SIG1 gene encodes a protein with a molecular weight of 65 kDa that contains at the amino-terminus two zinc finger-like sequence motifs. Epistasis experiments localize the action of Sig1p within the pheromone signalling pathway at a position at or shortly after the G-protein. We propose that Sig1p represents a novel negative regulator of G beta gamma-mediated signal transduction.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=395195Documentos Relacionados
- Down-regulation of G-protein-mediated Ca2+ sensitization in smooth muscle.
- G-protein-mediated desensitization of metabotropic glutamatergic and muscarinic responses in CA3 cells in rat hippocampus.
- Genetic and molecular analyses of mutations involved in Drosophila raf signal transduction.
- Evidence for an inhibitory effect of protein kinase C on G-protein-mediated repetitive calcium transients in hamster eggs.
- Plant Defense Response to Fungal Pathogens (II. G-Protein-Mediated Changes in Host Plasma Membrane Redox Reactions).