Autophagy is a process of bulk degradation of cytoplasmic components which are sequestered in double-membrane vesicles (autophagosomes) that deliver the contents to the lysosomal/vacuolar system for degradation. Apg7L is a homodimeric ubiquitin-activating E1-like enzyme essential for Apg8 and Apg12 conjugation that mediates membrane fusion in autophagy. This enzyme activates the C-terminal glycine of both ubiquitin-like proteins (UBLs) Apg8 and Apg12 in an ATP-dependent manner. Its activity is essential for the conjugation of Apg8 proteins to the lipid phosphatidylethanolamine (PE), and the conjugation of Apg12L to Apg5L, and is a critical component for the initiation of any in vitro conjugation reactions. Accession # NP_006386.