Table 1.
Composition and substrate preference of 3 classes of PI3Ks in mammalian cells
| Subunits |
||||||
|---|---|---|---|---|---|---|
| Class | Catalytic subunit | Regulatory subunit | Lipid substrates | Products | Function in autophagy | |
| Class I PI3K | Class IA |
PIK3CAPIK3CBPIK3CD |
PIK3R1PIK3R2PIK3R3 |
PtdInsPtdIns4PPtdIns(4,5)P2 | PtdIns3PPtdIns(4,5)P2PtdIns(3,4,5)P3 | Anti-autophagy |
| |
Class IB |
PIK3CG |
PIK3R5PIK3R6 |
|
|
|
| Class II PI3K |
PIK3C2APIK3C2BPIK3C2G |
— |
PtdInsPtdIns4P |
PtdIns3PPtdIns(3,4)P2 |
Pro-autophagy |
|
| Class III PtdIns3K | PIK3C3 | PIK3R4 | PtdIns | PtdIns3P | Pro-autophagy | |
Dash (−) indicates that it does not exist in mammalian cells.