Figure 1.

(Color online) The process of autophagy. When autophagy is induced, small flattened vesicles called isolation membranes or phagophores appear in the cytoplasm and expand to form double membrane vesicles called autophagosomes, which enclose various cellular material in a selective or non-selective manner. The outer autophagosomal membrane fuses with the lysosome in mammalian cells or the vacuole in yeast and plant cells to allow degradation of the inner membrane and sequestered material by hydrolases within the lysosome/vacuole. Degradation products are exported from the lysosomal/vacuolar lumen to the cytoplasm and recycled in various ways.