Table 1 The functions of each component in the autophagy complex involved in the autophagy machinery
Complex | Components | Functions | |
|---|---|---|---|
Yeast | Mammals | ||
Atg1/ULK1/2 complex | Atg1 | ULK1/2 | It is the only ATG protein with kinase activity and phosphorylates several other ATG proteins (ATG9, BECN1, ATG14L) for the PAS, autophagosome elongation and maturation |
Atg13 | ATG13 | It serves as a linker among ULK1/2, FIP200 and ATG101 | |
Atg17 | RB1CC1/FIP200 | It is a scaffold protein for ULK1/2 and ATG13 and serves as a scaffold protein for the ULK1/2 complex | |
– | ATG101 | It interacts with ATG13 | |
BECN1 complex | Atg6 | Beclin1 | It is a core component in class III PI3KI/II and binds lipids. It also associates with UVRAG for autophagosome elongation and maturation |
| Â | VPS34 | It is a catalytic subunit of class III PI3K to generate PI3P | |
| Â | VPS15 | It is a protein kinase involved in the PI3P pathway | |
Atg14 | ATG14L (Barkor) | It associates with the BECN1 complex for membrane targeting | |
ATG9A complex | Â | ATG9A | It is the only transmembrane protein among ATG proteins and forms homotrimer for the PAS, nucleation and autophagosome formation |
Atg18 | WIPI1/2 | It attaches to PI3P for the transportation of ATG9 | |
Atg2 | ATG2A | It attaches to WIPW1/2 | |
Ubiquitin-like complex | Atg8 | LC3A-C, GABARAP | It is a ubiquitin-like protein and ligates with PE for autophagosome elongation and sealing |
Atg12 | ATG12 | It is another ubiquitin-like protein and ligates with ATG5 to form an E3-like ligase with ATG16 | |
Atg4 | ATG4A-D | It is a protease required for the cleavage and activation of proLC3/GABARAP at the C-terminus for conjugation and further deconjugation of LC3/GABARAP-PE | |
Atg7 | ATG7 | It serves as an E1-like enzyme for LC3 and ATG12 conjugation | |
Atg3 | ATG3 | It serves as an E2-like enzyme for LC3/GABARAP conjugation with PE | |
Atg10 | ATG10 | It serves as an E2-like enzyme for ATG12 conjugation with Atg5 | |
Atg5 | ATG5 | It covalently binds to ATG12 and associates with ATG16 to form the E3-like enzyme complex | |
Atg16 | ATG16L1 | It is a part of the E3-like enzyme complex along with ATG12 and ATG5 | |