Fig. 1. Schematic pathways of autophagy.

Baseline autophagy is a dynamic multi-step process, comprising several compartments, including the pre-autophagosomal sequestering phagophore and the autophagosome, which is enriched in LC3. The autophagosome can fuse with endosomes to form the amphisome, which may be involved in the degradation of internalized species via endocytosis. Either autophagosomes or amphisomes may then fuse with the lysosome to generate autolysosomes or autophagolysosomes, respectively. Autolysosomes clear accumulating intracellular debris, like misfolded proteins and defective organelles, while autophagolysosomes may degrade internalized species via endocytosis and the endosomal pathways (i.e. extracellular amyloid, pathogens).