Ubiquitin-like protein conjugated to phosphatidylethanolamine; role in membrane fusion and phagophore expansion during autophagosome formation; deconjugation is required for biogenesis; targets Atg1p to autophagosomes; binds to the Atg1p-Atg13p complex, triggering its vacuolar degradation; role in vacuolar membrane protein turnover during early stationary phase; efficiently forms a thioester bond with E1, Atg7p; component of autophagosomes and Cvt vesicles; targeted to vacuole via AP-3 pathway