Autophagy is an essential cellular process, used by cells to degrade damaged and unwanted proteins (Carroll et al., 2015). It also produces amino acids which can be used for anabolic processes within the cell. It is controlled by mTOR (Lin et al., 2015). When mTOR is activated, autophagy is suppressed. mTOR can be suppressed by low amino acid concentrations, allowing autophagy to produce more amino acids.
References: Carroll, B., Korolchuk, V., Sarkar, S. (2015). Amino acids and autophagy: cross-talk and co-operation to control cellular homeostasis. Amino Acids, 47(10), pp2065-2088 Lin S., Leng Z., Guo Y., Cai L., Cai Y., Li N., Shang H., Le W., Zhao W., Wu Z. (2015). Suppression of mTOR pathway and induction of autophagy-dependent cell death by cabergoline. Oncotarget, 5744 (Epub ahead of print)