Protective role of S-adenosyl-l-methionine against hydrochloric acid stress in Saccharomyces cerevisiae

S-adenosyl-l-methionine (AdoMet, 1 mM) protects the stationary phase cells of Saccharomyces cerevisiae against the killing effect of acid (10 mM HCl, pH ∼ 2). Both the acid and the acid plus AdoMet treatment for 2 h increased the plasma membrane H+-ATPase activity; thereafter it decreased to the basal level. AdoMet partially recovered the intracellular pH (pHin) that dropped in presence of acid. AdoMet treatment facilitated acid induced phospholipid biosynthesis as well as membrane proliferation, which was reflected in the cellular lipid composition.