Figure 1.

Overview of the autophagy pathway. Autophagosome biogenesis is initiated with the nucleation of the phagophore, a double-membrane structure. Expansion of the phagophore leads to the engulfment of the autophagic cargo. The edges of the phagophore are eventually closed to form a sealed autophagosome. The outer membrane of the completed autophagosome fuses with a lytic compartment, resulting in the degradation of the inner autophagosomal membrane and the autophagic cargo by resident hydrolyses. Finally, the resulting macromolecules are released back into the cytosol.