Figure 1.

Schematic representation of autophagosome formation. The activation of the ATG (AuTophaGy-related) complex induces the formation of a pre-autophagosomal structure (PAS). The recruitment of proteins and lipids induces membrane expansion and then its closure to form the autophagosome, enveloping proteins and organelles destined for degradation. An important step in the PAS elongation is the recruitment of the protein light chain 3 (LC3), an important marker of autophagic flux. After induction of autophagy, LC3 is cleaved and turned into its activated form, LC3-I. When recruited to the autophagosome, LC3-I is converted to its lipidated form LC3-II, that can bind on both the inner and outer surface of the autophagosome. In the final stage, the autophagosome merges with the lysosome, and the cargo is completely degraded.