Cytochrome c promotes caspase-9 activation by inducing nucleotide binding to Apaf-1.

摘要: We report here the biochemical analysis of reconstituted de novo procaspase-9 activation using highly purified cytochrome c, recombinant apoptotic protease-activating factor-1 (Apaf-1), and procaspase-9. Using a nucleotide binding assay, we found that Apaf-1 alone bound dATP poorly to was significantly stimulated by c. The induces formation multimeric Apaf-1. c complex, apoptosome. Procaspase-9 also synergistically promotes in c-dependent manner. apoptosome remained as dATP, not dADP. A nonhydrolyzable ATP analog, ADPCP (beta,gamma-methylene adenosine 5'-triphosphate), able support caspase place or ATP. These data indicate key event Apaf-1-mediated caspase-9 is c-induced