PMC

Figure 1. Schematic representation of the connection between autophagy and MTOR signaling mediated by lysosomes. (A) Induction of autophagy results in autophagosome-mediated delivery of proteins to lysosomes. The v-ATPase complex ensures optimal acidic pH for lysosomal proteases that break down proteins into amino acids, which in turn activate MTOR complex 1 associated with the v-ATPase complex. MTORC1 activation then results in feedback inhibition of autophagosome generation. (B) Inhibition of the v-ATPase proton pump, neutralization of lysosomal acidity or block of lysosomal proteases decreases autophagic protein degradation and intralysosomal amino acid levels, likely leading to MTORC1 inactivation and increased formation of autophagosomes.