FIG. 6.

The LC3 conjugation system. LC3 is processed by ATG4 to reveal a C-terminal glycine (LC3-I). ATG7, an E1-like enzyme, activates LC3-I and transfers it to the E2-like enzyme ATG3. The ATG12–ATG5-ATG16L1 complex may participate as an E3 ligase in the conjugation of PE to LC3-I to create LC3-II, which can associate with the phagophore. LC3-II can subsequently be cleaved by ATG4 to release LC3 (deconjugation). PE, phosphatidylethanolamine. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars