Metabolism of alpha-factor by a mating type cells of Saccharomyces cerevisiae.
When a mating type cells of Saccharomyces cerevisiae are exposed to the mating pheromone alpha-factor in liquid cultures, there is a time-dependent loss of alpha-factor activity from the culture fluid. This loss of biological activity can be directly correlated with the proteolysis of the pheromone by a mating type cells. The metabolism of alpha-factor by a mating type cells may be measured by using either in vitro 125I-labeled or in vivo 35S-labeled pheromone. Addition of chloroquine to growing cultures of a mating type cells at concentrations which cause no detectable alterations in cell growth produces a potentiation of alpha-factor mediated cell cycle arrest. This potentiation of alpha-factor activity is directly correlated with the inhibition of alpha-factor proteolysis. Thus, while proteolytic digestion of alpha-factor appears to be related to the mechanism whereby a mating type cells "detoxify" alpha-factor and recover from cell cycle arrest, proteolysis of the mating factor is not necessary for alpha-factor mediated cell cycle arrest.
D002738:Chloroquine / Q000494:pharmacology; D005827:Genetics, Microbial; D007700:Kinetics; D010434:Pepsin A; D010455:Peptides / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism / Q000502:physiology*; D013464:Sulfuric Acids / Q000378:metabolism
D010455:Peptides; D013464:Sulfuric Acids; D002738:Chloroquine; D010434:Pepsin A