(A) Autophagosome maturation occurs through several stages: initiation, elongation and termination. Autophagosomes form from a preautophagosomal structure (PAS), then mature to a phagophore that entraps cargo to a fully formed and sealed autophagosome prior to fusion with the endocytic compartment and termination at the lysosome (autolysosome). (B) Ubiquitin-like (UBL) conjugation machinery drive the formation of autophagosomes through the action of E1-like (autophagy gene 7 (ATG7)), E2-like (ATG3 and ATG10) and finally E3-like steps (ATG5–ATG12–ATG16 complex). This allows the conjugation of ATG8 (LC3 and γ-aminobutyric acid receptor associated proteins (GABARAP) in higher eukaryotes) to phosphatidylethanolamine (PE; red) that allows cells to target specific structures for degradation by selective autophagy.