| Protease type |
Cys-dependent, caspase family |
Ser-dependent, subtilase family |
Ser-dependent, subtilase family |
| Cleavage specificity |
Strictly D-specific |
Strictly D-specific |
Strictly D-specific |
| Synthesized as |
Pro-enzyme |
Pre–pro-enzyme |
Inferred as pre–pro-enzyme |
| Pro-enzyme processing |
Stimuli-induced, autocatalytic or by an upstream caspase |
Constitutive, autocatalytic |
Inferred as constitutive, autocatalytic |
| Mature enzyme |
Dimer of heterodimers, ∼12 and 20 kDa subunits |
Single polypeptide chain, ∼80 kDa |
Single polypeptide chain, ∼ 80 kDa |
| Localization |
Intracellular, mainly cytoplasmic |
Extracellular in healthy tissues; shifted to cytoplasm upon PCD induction |
Extracellular |
| Role in PCD |
Initiation, execution |
Upstream of mitochondrial events, cleavage of foreign protein(s) |
Rubisco proteolysis |
| Protein targets known |
Various proteins of host and pathogen origin |
VirD2 protein of Agrobacterium tumefaciens
|
? |
| Preferred peptide recognition pattern |
VDVAD (caspase-2), DEVD (caspase-3, -7), VEID (caspase-6) IETD (caspase-8), LEHD (caspase-9) |
VEID>>YVAD∼VAD∼IETD ∼LEHD>>WEHD∼STATD ∼VDVAD |
VKMD>VNLD∼VEHD>VAD ∼IETD∼LEHD>LEVD∼YVAD |
| |
|
DEVD derivative is not recognized |
DEVD, VEID, WEHD, VDVAD derivatives are not cleaved |
