The Progress of Mitophagy and Related Pathogenic Mechanisms of the Neurodegenerative Diseases and Tumor

Figure 2

The type of autophagy and its basic process [8]. (1) Microautophagy refers to the sequestration of cytosolic components directly by lysosomes through invaginations in their limiting membrane. Microautophagy-like processes in fungi are involved in selective organelle degradation. (2) In the case of macroautophagy, the cargoes are sequestered within a unique double-membrane cytosolic vesicle, an autophagosome. The autophagosome is formed by expansion of the phagophore. (3) Lysis of the autophagosome inner membrane and breakdown of the contents occur in the autolysosome, and the resulting macromolecules are released back into the cytosol through membrane permeases. CMA involves direct translocation of unfolded substrate proteins across the lysosome membrane through the action of a cytosolic and lysosomal chaperone hsc70 and the integral membrane receptor LAMP-2A.