Table 2. A selection of proteases implicated in dPCD processes.
| Tissue/Process | Name | Species | MEROPS clan/family/ID | Catalytic type | Localization | Mode of action | Reference |
|---|---|---|---|---|---|---|---|
| Xylem | XCP1 | At | CA/C1/C01.065 | Cysteine | Vacuole and to a lesser extend in cytoplasm | Post-mortem clearance | (Avci et al., 2008) |
| XCP2 | At | CA/C1/C01.065 | Cysteine | Vacuole and to a lesser extend in cytoplasm | Post-mortem clearance | (Avci et al., 2008) | |
| Tr-cp14 | Tr | CA/C1/C01.065 | Cysteine | ER | n.d. | (Mulisch et al., 2013) | |
| AtMC9 | At | CD/C14/C14.034 | Cysteine | Nucleocytoplasm, apoplast, and vacuole | Post-mortem clearance | (Vercammen et al., 2006); (Escamez et al., 2016); (Bollhöner et al., 2013) | |
| Tapetum | CEP1 | At | CA/C1/A03 | Cysteine | Vacuole | Pro-PCD | (Zhang et al., 2014) |
| AtCP51 | At | CA/C1/A26 | Cysteine | n.d. | Pro-survival | (Yang et al., 2014) | |
| OsAP25 | Os | AA/A1/UPW | Aspartic | n.d. | Pro-PCD | (Niu et al., 2013) | |
| OsAP37 | Os | AA/A1/UPW | Aspartic | n.d. | Pro-PCD | (Niu et al., 2013) | |
| UNDEAD | At | AA/A1/A01.A49 | Aspartic | Predicted mitochondrial | Pro-survival | (Phan et al., 2011) | |
| Suspensor | CEP1 | At | CA/C1/C01.A03 | Cysteine | Subdomains of ER | n.d. | (Zhou et al., 2016) |
| NtCP14 | Nt | CA/C1/C01.A13 | Cysteine | ER | Pro-PCD | (Zhao et al., 2013) | |
| NtCYS | Nt | n.p. | inhibitor | ER | Pro-survival | (Zhao et al., 2013) | |
| mcII-Pa | Pa | CD / C14 / C14.036 | Cysteine | Nucleus | Promotes nuclei degradation | (Bozhkov et al., 2005) | |
| Endosperm | CEP2 | At | CA/C1/C01.A01 | Cysteine | Ricinosome-like vesicles | n.d. | (Hierl et al., 2014) |
| Inner integument | RD21A | At | CA/C1/C01.064 | Cysteine | Vacuole | n.d. | (Andème Ondzighi et al., 2008) |
| PDI5 | At | n.p. | inhibitor | Vacuole | Pro-survival | (Andème Ondzighi et al., 2008) | |
| δVPE | At | CD/C13/C13.A01 | Cysteine | Cytosol, Apoplast | Pro-PCD | (Nakaune et al., 2005) | |
| Nucellus | CysEP | Rc | CA/C1/C01.010 | Cysteine | Ricinosomes | n.d. | (Greenwood et al., 2005) |
| HvVPE2a | Hv | CD/C13/C13.001 | Cysteine | Apoplast | n.d. | (Linnestad et al., 1998) | |
| Leaf senescence | At2-MMP | At | MA/M10/M10.012 | Metallo | Predicted plasma membrane | Pro-survival | (Golldack et al., 2002) |
| Floral senescence | FtSH4 | At | MA/M41/M41.004 | Metallo | Mitochondria | Pro-survival | (Zhang et al., 2017a) |
n.d. not determined; n.p. not present; At - Arabidopsis thaliana; Tr - Trifolium repens; Os - Oryza sativa; Nt - Nicotiana tabacum; Pa - Picea abies; Rc - Ricinus communis; Hv - Hordeum vulgare