Sugar Metabolisms Altered By Undissociated Forms of Organic Acids Based on the Emergence of [ GAR ⁺ ] Cells in Saccharomyces cerevisiae

The glucose repression system is a mechanism for effective energy acquisition by glucose assimilation in microorganisms. In yeast, Saccharomyces cerevisiae , which is known as a prion‐like protein [ GAR + ], is involved in the bypass of glucose repression. It has been reported that the emergence of [ GAR + ] cells was promoted by lactate and acetate. Herein, we examined the promotion of [ GAR + ] emergence by pyruvate (both the end product of glycolysis and a precursor of the synthesis of organic acids), and we compared the results of pyruvate with those of lactate or acetate. Pyruvate, as well as other organic acids, promoted [ GAR + ] emergence in all S. cerevisiae strains tested, but the induction patterns of [ GAR + ] emergence by organic acids differed among the strains. The ability of all three organic acids to induce [ GAR + ] was weakened at pH values greater than the p K a value of each organic acid, indicating that the undissociated forms of organic acids may promote [ GAR + ] emergence.