autophagy macroautophagy The major inducible pathway for the general turnover of cytoplasmic constituents in eukaryotic cells, it is also responsible for the degradation of active cytoplasmic enzymes and organelles during nutrient starvation. Macroautophagy involves the formation of double-membrane-bounded autophagosomes which enclose the cytoplasmic constituent targeted for degradation in a membrane-bounded structure. Autophagosomes then fuse with a lysosome (or vacuole) releasing single-membrane-bounded autophagic bodies that are then degraded within the lysosome (or vacuole). Some types of macroautophagy, e.g. pexophagy, mitophagy, involve selective targeting of the targets to be degraded. Targeted macroautophagy sometimes targets regions of cytoplasm containing non-self, such as virus particles or components (e.g. see PMID:20159618). As this is essentially the same process as macroautophagy that encloses and digests only self, the term autophagy is still used despite the enclosure of some non-self (non-auto) entities. GO:0016236 autophagy biological_process GO:0034262