Table 1.
Human clan CD proteases, their biological functions, primary specificity, and activation mechanisms.
| Clan CD member | Biological Role | Primary specificity | Activation mechanism |
|---|---|---|---|
| Caspase-1, 4, 5 | Inflammatory caspases | Asp | No consensus – probably dimerization |
| Caspase-12 | Putative pseudocaspase - inflammation | - | |
| Caspase-9 | Intrinsic pathway apical caspase | Asp | Dimerization |
| Caspase-8, 10 | Extrinsic pathway apical caspases | Asp | Dimerization |
| FLIP | Pseudocaspase – extrinsic pathway | - | |
| Caspase-3, 6, 7 | Apoptotic effector (executioner) caspases | Asp | Intra-domain cleavage |
| Caspase-2 | “Multifunctional” caspase | Asp | No consensus |
| Caspase-14 | Keratinocyte differentiation | Asp | Intra-domain cleavage |
| MALT1 | B, T-cell activation via NFkB | Arg | Dimerization |
| Legumain | Antigen presentation, lysosomal protein degradation | Asn | Removal of N-domain |
| Separase | Sister chromatid separation during anaphase | Arg | Removal of blocking inhibitor |
| PIGK | C-terminal processing of proteins destined for GPI anchor addition | Asn/Ser* | Unknown |