The apoptosome is a multi-protein complex that forms in response to intrinsic apoptotic signals. Its formation is primarily triggered by the release of cytochrome c from the mitochondria into the cytosol. Once in the cytosol, cytochrome c binds to Apaf-1 (apoptotic protease activating factor-1), leading to the recruitment and activation of caspase-9. This cascade ultimately results in the activation of executioner caspases, such as caspase-3, which lead to cell death.
