Apoptotic Peptidase Activating Factor 1 (APAF1)

Apoptotic peptidase activating factor 1 is a proteincontains several copies of the WD40 repeat domain, a caspase recruitment domain (CARD), and an ATPase domain (NB-ARC). Upon binding cytochrome c and dATP, this protein forms an oligomeric apoptosome. The apoptosome binds and cleaves caspase 9 preproprotein, releasing its mature, activated form. The precise mechanism for this reaction is still debated though work published by Guy Salvesen suggests that the apoptosome may induce caspase 9 dimerization and subsequent autocatalysis. Activated caspase 9 stimulates the subsequent caspase cascade that commits the cell to apoptosis.Alternative splicing results in several transcript variants encoding different isoforms.