Activation of yeast mannan synthetase by alpha factor pheromone.

The Saccharomyces cerevisiae mating pheromone alpha factor induces the activation of yeast mannan synthetase both in vivo and in vitro. In vivo the activating effect of the pheromone on the synthetase is specific for cells of the alpha mating type, while in vitro alpha factor is able to exert its action on the synthetase of either cell type (MAT a, MAT alpha and MAT a/MAT alpha).