caspase-9;
CASP-9;
ICE-like apoptotic protease 6;
ICE-LAP6;
apoptotic protease Mch-6;
apoptotic protease-activating factor 3;
APAF-3

Hydrolases;
Acting on peptide bonds (peptidases);
Cysteine endopeptidases

Strict requirement for an Asp residue at position P1 and with a marked preference for His at position P2. It has a preferred cleavage sequence of Leu-Gly-His-Asp!Xaa

Caspase-9 is an initiator caspase, as are caspase -2 (EC 3.4.22.55), caspase-8 (EC 3.4.22.61) and caspase-10 (EC 3.4.22.63) [1]. Caspase-9 contains a caspase-recruitment domain (CARD) in its N-terminal prodomain, which plays a role in procaspase activation [1]. An alternatively spliced version of caspase-9 also exists, caspase-9S, that inhibits apoptosis, similar to the situation found with caspase-2 [1]. Phosphorylation of caspase-9 from some species by Akt, a serine-threonine protein kinase, inhibits caspase activity in vitro and caspase activation in vivo [1]. The activity of caspase-9 is increased dramatically upon association with the apoptosome but the enzyme can be activated without proteolytic cleavage [2,3]. Procaspase-3 is the enzyme's physiological substrate [2]. Belongs in peptidase family C14.

1  [PMID:11104820]

Chang HY, Yang X.

Proteases for cell suicide: functions and regulation of caspases.

Microbiol. Mol. Biol. Rev. 64 (2000) 821-46.

2  [PMID:16630893]

Yin Q, Park HH, Chung JY, Lin SC, Lo YC, da Graca LS, Jiang X, Wu H.

Caspase-9 holoenzyme is a specific and optimal procaspase-3 processing machine.

Mol. Cell. 22 (2006) 259-68.

3  [PMID:12620239]

Boatright KM, Renatus M, Scott FL, Sperandio S, Shin H, Pedersen IM, Ricci JE, Edris WA, Sutherlin DP, Green DR, Salvesen GS.

A unified model for apical caspase activation.

Mol. Cell. 11 (2003) 529-41.

4

Salvesen, G.S. and Boatright, K.M.

Caspase-9.

In: Barrett, A.J., Rawlings, N.D. and Woessner, J.F. (Eds.), Handbook of Proteolytic Enzymes, 2nd ed., Elsevier, London, 2004, p. 1296-1298.