Figure 1.

Overview of three types autophagy. (a) Macroautophagy is initiated by assembly of double-membrane called phagophore. Non-selective or selective cargoes are enclosed in autophagosomes. Autophagosomes fuse with lysosomes to become autolysosomes. The cargoes within autolysosome are digested by lysosomal enzymes. (b) In microautophagy, the cargoes directly engulfed by lysosomal membrane and degraded in the lysosome. (c) In chaperone-mediated autophagy (CMA), a selective subset of cytosolic proteins containing a KFERQ-motif is recognized by heat shock cognate protein of 70 kDa (Hsc70). They are delivered to lysosomal membrane by binding to lysosomal-associated membrane protein 2A (LAMP2A). The cargoes are unfolded and translocated inside the lysosome where they are degraded by lysosomal enzymes.