FIGURE 1: Methionine restriction-induced autophagy is causal for longevity-mediating enhancement of vacuolar acidification.

Methionine restriction (MetR) specifically induces autophagy during yeast chronological aging, which in turn leads to an increased number of cells bearing acidic vacuoles and ultimately to increased chronological lifespan (CLS). Genetic inhibition of vacuolar acidification by the v-ATPase abrogates the longevity effect of MetR. Also, genetic inhibition of autophagy abrogates the MetR-induced acidification of vacuoles, as well as the MetR-induced extension of CLS.