Inhibition of membrane Ca2+-ATPase of Saccharomyces cerevisiae by mating pheromone α-factor in vitro

Abstract

Summary: Plasma membrane Ca²⁺-ATPase of Saccharomyces cerevisiae was solubilized and partially purified by calmodulin-affinity chromatography. The activity of Ca²⁺-ATPase isolated from MATa cells was inhibited by physiological concentrations of the mating pheromone α-factor in a dose-dependent manner. The enzyme prepared from a receptor-deficient sterile mutant cells (Δste2) was similarly inhibited by α-factor, but the enzyme from MATα cells was resistant to the mating pheromone. We suggest that the inhibition may be involved in the α-factor-induced increase of Ca²⁺ uptake reaction of MATa cells.