Protein Domain : Peptidase C14, p20 domain IPR001309

Type	Domain
Description	This group of sequences represent the p20 subunit found in caspases. Caspases are composed of an N-terminal pro-domain that is cleaved during activation, and C-terminal catalytic and interaction domains [ ]. All caspases contain two essential caspase catalytic domains: the p20 subunit (20kDa) and the p10 subunit (10kDa) (), which are derived from the p45 (45kDa) precursor. Caspases are tightly regulated proteins that require zymogen activation to become active, and once active can be regulated by caspase inhibitors. Activated caspases are cysteine proteases (MEROPS clan CD, family C14) that use the sulphydryl group of a cysteine side chain for catalysing peptide bond cleavage at aspartyl residues in their substrates. The key catalytic residues, a cysteine and a histidine, are on the p20 subunit. Caspases are mainly involved in mediating cell death (apoptosis), either as initiators that trigger the cell death process, or as effectors of the process itself [ , ]. At the end of the cascade, caspases act on a variety of signal transduction proteins, cytoskeletal and nuclear proteins, chromatin-modifying proteins, DNA repair proteins and endonucleases that destroy the cell by disintegrating its contents, including its DNA. Caspases can have roles other than in apoptosis, such as caspase-1 (interleukin-1 beta convertase) (), which is involved in the inflammatory process. The activation of apoptosis can sometimes lead to caspase-1 activation, providing a link between apoptosis and inflammation, such as during the targeting of infected cells. Caspases may also be involved in cell differentiation [ ].
Short Name	Pept_C14_p20