cIAP1 is a member of the Inhibitor of Apoptosis family that inhibit apoptosis by interfering with the activation of caspases. cIAP1 inhibits apoptosis induced by serum deprivation and menadione, a potent inducer of free radicals. In general, the IAP proteins function through direct interactions to inhibit the activity of several caspases, including caspase-3, caspase-7, and caspase-9. In addition, binding of IAP family members to the mitochondrial protein Smac blocks their interaction with caspase-9, thereby allowing the processing and activation of the caspase.
