UCSF

Key PointsAutophagy is a conserved catabolic process that degrades cytoplasmic constituents and organelles in the lysosome.Autophagy was originally believed to non-selectively sequester and degrade cytoplasmic material. However, it is increasingly being appreciated that autophagy is a selective process, resulting in the targeted engulfment of specific cargoes such as mitochondria, peroxisomes and ribosomes, and protein aggregates.Although protein catabolism is a salient feature of autophagy, recent research has uncovered that autophagy mobilizes diverse cellular energy and nutrient stores such as lipids, carbohydrates and iron.In certain contexts, autophagic degradation is tightly linked with anabolic processes within cells. For example, autophagy-derived amino acids are important for enabling protein synthesis in mammalian cells.During starvation, multiple transcriptional networks coordinate the autophagic degradation of intracellular lipids (lipophagy) in conjunction with other processes, promoting lipid catabolism.Recent research demonstrating the selective autophagic degradation of iron–ferritin complexes has uncovered the importance of autophagy in mobilizing cellular nutrient stores.