Hydrolases;
Acting on peptide bonds (peptidases);
Cysteine endopeptidases
Reaction(IUBMB)
Strict requirement for Asp at position P1 and has a preferred cleavage sequence of Val-Glu-His-Asp!
Comment
Caspase-6 is an effector/executioner caspase, as are caspase-3 (EC 3.4.22.56) and caspase-7 (EC 3.4.22.60) [2]. These caspases are responsible for the proteolysis of the majority of cellular polypeptides [e.g. poly(ADP-ribose) polymerase (PARP)], which leads to the apoptotic phenotype [2]. Caspase-6 can cleave its prodomain to produce mature caspase-6, which directly activates caspase-8 (EC 3.4.22.61) and leads to the release of cytochrome c from the mitochondria. The release of cytochrome c is an essential component of the intrinsic apoptosis pathway [1]. The enzyme can also cleave and inactivate lamins, the intermediate filament scaffold proteins of the nuclear envelope, leading to nuclear fragmentation in the final phases of apoptosis [2,4,5,6]. Belongs in peptidase family C14.
Takahashi A, Alnemri ES, Lazebnik YA, Fernandes-Alnemri T, Litwack G, Moir RD, Goldman RD, Poirier GG, Kaufmann SH, Earnshaw WC.
Title
Cleavage of lamin A by Mch2 alpha but not CPP32: multiple interleukin 1 beta-converting enzyme-related proteases with distinct substrate recognition properties are active in apoptosis.
