Analysis of exogenous leucine supplement functions as a calorie restriction (CR) mimetic of Saccharomyces cerevisiae

초록

Leucine prototrophic yeast exhibits extended longevity and related phenotypes similar to yeast grown under calorie restriction (CR). The extended longevity of leucine prototrophic yeast is thought to be a function of abundant cellular leucine level. To verify the similar effects of leucine-induced and CR-induced chronological life span (CLS), leucine prototrophic and auxotrophic yeast cells were grown in the presence or absence of exogenous leucine supplementation and CR condition. Then, their lifespan and various phenotypes were examined. Leucine supplementation induced CLS extension, increased cellular Cox2p levels, and decreased cell death. These phenotypes were similar to those of the cells grown under CR. Interestingly, simultaneous treatment with leucine supplementation and CR led to a synergistic effect on CLS and cellular Cox2p levels compared to the observations in cells treated with either leucine supplementation or CR. Similarly, the rate of cell death of simultaneously treated cells was significantly lower than that of cells undergoing either treatment. Leucine-induced CLS extension and a decrease in the rate of cell death observed in this study verified the function of leucine in cell death prevention and CLS extension in yeast. Interestingly, leucine-induced changes were similar to CR-induced changes. The results in this study suggest that leucine can function as a CR mimetic.