Table 1.
Autophagy-related (Atg) genes and their protein function in autophagy
| Genes | Protein function description | References | |
|---|---|---|---|
| Mammals | Yeast | ||
|
ULK1/2 (Unc51-like kinase 1 and 2) |
Atg1 | Is part of the ULK-ATG13-ATG101-FIP200 complex and phosphorylates Beclin1; interacts with Atg13; is involved in initiation of autophagy, membrane targeting, membrane curvature sensing, and lipid vesicle tethering | [51–54] |
| ATG2A/B | Atg2 | Is part of the ATG9/ATG12-WIPI complex, which is important for ATG9 recruitment to expand autophagosome | [55, 56] |
| ATG3 | Atg3 | E2-like enzyme in LC3 lipidation; autocatalyzes itself to form ATG12-ATG3 complex for maintaining mitochondrial homeostasis | [57–59] |
| ATG4A-D | Atg4 | Cysteine protease to process Atg8 by removing its last amino acid; and deconjugate Atg8–PE; involved in LC3 activation and delipidation | [60, 61] |
| ATG5 | Atg5 | Is part of the ATG12-ATG5 complex involved in autophagosome formation/elongation, acting as an E3-like enzyme in LC3 lipidation; interacts with Atg16 and plays crucial roles in autophagy. | [62, 63] |
| Beclin1 | Atg6 | Is subunit of the VPS34-PI3K complex; recruits Atg14 or Vps38; interacts with Bcl-2; and lipid binding and membrane deformation | [64, 65] |
| ATG7 | Atg7 | E1-like enzyme interacting with E2 enzyme Atg10 or Atg3 involved in LC3 and ATG12 conjugation; and forms a thioester bond with Atg8 | [66–68] |
| MAP 1 LC3A-C, GABARAPs, GATE-16 | Atg8 | Modifier; Ubiquitin-like module conjugated to PE and used as autophagosome marker; recognizes the cargo-specific adaptors; and in vitro membrane tethering | [69–71] |
| ATG9L1/L2 | Atg9 | Transmembrane protein; interacts with ATG2-WIPI complex; shuttles between PAS and peripheral organelles to deliver lipids/factors during phagophore expansion; and self-interaction | [72, 73] |
| ATG10 | Atg10 | E2-like enzyme in ATG12 conjugation with Atg5 | [74–76] |
| ATG12 | Atg12 | Modifier; ubiquitin-like module conjugated to Atg5; forms an E3 complex with Atg5 and Atg16; and interacts with Atg3 | [59, 62, 77] |
| ATG13 | Atg13 | Is part of the ULK-ATG13-ATG101-FIP200 complex involved in initiation of autophagy; targets mTOR signaling pathway; interact with Atg1 and bridges Atg1 and Atg17-Atg31-Atg29; recruits the Vps34 complex via Atg14; binds to LC3; and interacts with Atg101 | [78–80] |
|
ATG14L (Barkor) |
Atg14 | Is subunit of VPS34-PI3K complex; interacts with Beclin1 to assemble the autophagic-specific complex; membrane targeting and membrane curvature sensing; and promote membrane fusion | [81–83] |
| ATG16L1/L2 | Atg16 | Binds to ATG5-ATG12 complex acting as part of the E3 enzyme complex | [84–86] |
| RB1CC1/ FIP200 | Atg17 | Is part of the ULK-ATG13-ATG101-FIP200 complex involved in initiation of autophagy; interacts with Atg13 and Atg9; forms ternary complex with Atg31 and Atg29; and senses membrane curvature | [53, 78, 87] |
| WIPI1–4 | Atg18 | Is part of the ATG2-WIPI complex which is important for ATG9 recruitment to autophagosome; binds to PI3P; required for the retrograde transport of Atg9; and complexes with Atg2 | [88, 89] |
| ATG101 | – | Interact with Atg13 and forms the ULK-ATG13-ATG101-FIP200 complex | [90, 91] |
-, This protein has not been identified