Down regulation of the alpha-factor pheromone receptor in S. cerevisiae.
The peptide pheromone, alpha-factor, was found to elicit down regulation of receptor sites on yeast a cell targets. Cellular uptake of alpha-factor accompanied the loss of receptor sites. Receptor-deficient a cells bearing a deletion of the STE2 gene were unable to internalize alpha-factor. Cultures were found to reaccumulate receptor sites following the initial period of down regulation; reaccumulation was dependent upon protein synthesis. Pheromone-resistant mutants, ste4-3 and ste5-3, retained the ability to down regulate receptors but failed to show reaccumulation. Our results suggest that alpha-factor-receptor complexes enter the cell by receptor-mediated endocytosis and that receptors are continuously lost and resynthesized in the presence of alpha-factor. We found no reduction of alpha-factor binding capacity in a cell cultures that had adapted to alpha-factor.
D000222:Adaptation, Physiological; D004705:Endocytosis; D005656:Fungal Proteins / Q000096:biosynthesis; D005800:Genes, Fungal; D000072235:Mating Factor; D010455:Peptides / Q000378:metabolism / Q000494:pharmacology*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors
D005656:Fungal Proteins; D010455:Peptides; D011956:Receptors, Cell Surface; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide; D014157:Transcription Factors; D000072235:Mating Factor