Melanoma inhibitor of apoptosis protein (ML-IAP) (ML-IAP)

Melanoma inhibitor of apoptosis protein (ML-IAP), also known as Livin or BIRC7, is a member of the inhibitor of apoptosis protein (IAP) family that plays a critical role in protecting cancer cells from programmed cell death [UniProt: Q96CA5]. It contains a single Baculovirus IAP Repeat (BIR) domain and a C-terminal RING finger domain, which are essential for its anti-apoptotic and E3 ubiquitin ligase activities [PMID: 11084333]. The BIR domain is the critical functional region that binds to and inhibits pro-apoptotic proteins, including activated caspase-3, caspase-7, and caspase-9, thereby preventing the execution of programmed cell death [PMID: 12107159]. Additionally, ML-IAP interacts with the endogenous IAP antagonist Smac/DIABLO, sequestering it to maintain the survival of cancer cells under stress [PMID: 15310651]. Because ML-IAP expression is largely restricted to fetal tissues and tumor cells, it serves as a highly specific target for cancer therapy with minimal expected impact on normal adult tissues [PMID: 18056468]. Therapeutic agents such as SMAC mimetics are designed to bind the BIR domain of ML-IAP with high affinity, displacing caspases and Smac to restore the apoptotic pathway [PMID: 24469444]. These inhibitors are being investigated for their ability to sensitize tumor cells to chemotherapy and radiation, potentially overcoming resistance mechanisms in aggressive cancers [PMID: 25860614]. Clinical development of ML-IAP-targeting drugs focuses on their role in combination therapies to enhance immune-mediated tumor cell killing and direct apoptosis induction.

Other names

LivinBIRC7Baculoviral IAP repeat-containing protein 7Kidney inhibitor of apoptosis proteinKIAP

SMAC mimetics bind to the BIR domain of ML-IAP, displacing pro-apoptotic proteins like Smac/DIABLO and caspases (caspase-3, -7, and -9), thereby neutralizing the anti-apoptotic effect and promoting programmed cell death in tumor cells.