Anti-Apaf-1 Antibody, clone 18H2 clone 18H2, from rat

Apoptotic protease-activating factor 1 (UniProt: O88879; also known as Apaf-1) is encoded by the Apaf-1 gene (Gene ID: 11783) in murine species. Apaf-1 contains a caspase recruitment domain (CARD), an ATPase domain (NB-ARC), few short helical domains and then several copies of the WD40 repeat domain. It is highly expressed in lung and spleen, weakly in brain and kidney and is not detectable in liver. Under basal conditions it is a monomeric protein, but oligomerizes under apoptotic conditions. The monomeric form is auto-inhibited in a closed conformation through a bound ADP at the nucleotide binding site. Under apoptosis signals ADP is exchanged for ATP and its binding to cytochrome c triggers a conformation change where WD repeat region swings out, which allows the NB-ARC domain to rotate and expose the contact areas for oligomerization. Oligomeric form is a heptameric ring that binds to cytochrome c and ATP and is known as the apoptosome. Oligomeric Apaf-1 mediates the cytochrome c-dependent autocatalytic activation of pro-caspase-9 to mature caspase-9, which then activates effector caspases 3, 6, and 7.