Autophagy and amino acids with their metabolites

Macroautophagy (hereafter referred to as autophagy) is a highly conserved cellular process that delivers proteins and organelles to the lysosome and controls the degradation of these substrates to facilitate homeostasis. In addition, it is an important process to adapt the availability of nutrients. Amino acids activate mammalian target of rapamaycin complex 1 (mTORC1), which is the key regulator of the autophagy signaling pathway. The depletion of amino acids negatively regulates mTORC1 and induces autophagy. Recent studies have shown that amino acids recruit mTORC1 to the lysosome by affecting vacuolar-type H+-ATPase (v-ATPase) and Rag guanosine triphosphatase A/B (RagA/B), thereby leading to the activation of mTORC1 on the lysosome and the inhibition of autophagy. Here, we review recent advances in the understanding of autophagy signaling by amino acids and their metabolites.