Amino acid sensing and regulation of mTORC1

► This review discusses recent findings on mechanisms that relate amino acids sufficiency to activation of the rapamycin-sensitive mTOR complex, mTORC1. ► We discuss how these mechanisms are changing our understanding of signaling control of mTOR. ► We highlight some general features of the amino acid-stimulated signaling pathways involved. ► We describe the GCN2 signaling starvation sensing mechanism induced under amino acid limitation.