Figure 1.

Classification of autophagy. Major types of autophagy. According to the way that eukaryotic cells deliver cytoplasmic cargo to lysosomes for degradation, autophagy can be divided into three major types. First, macroautophagy could both selectively and non-selectively engulf bulk cytoplasmic components by sequestering these cargoes to a specialized double-membrane vesicle known as the autophagosome; autophagosome is then fused with the lysosome, where the cargo is degraded and the resulting macromolecules are released into the cytosol for reuse. Second, the CMA only degrades soluble proteins in a selective manner through the Lamp1a receptor on the lysosome to recognize and translocate unfolding proteins. Third, microautophagy refers to the lysosome itself engulfing cytoplasmic material or large structures by invading the lysosome membrane.