Cellular inhibitor of apoptosis protein-1 (cIAP-1) is an anti-apoptotic protein that is able to bind to caspases and inhibit their activity. Additionally cIAP-1 contains a RING domain with E3 ubiquitin ligase activity that is able to mediate the regulation of NF-kB signaling through the ubiquitination and degradation of various substrate proteins. Depending on cellular context, the RING domain of cIAP-1 can either promote or inhibit apoptosis.
