Apoptosis repressor with CARD (ARC)

Apoptosis repressor with CARD (ARC), encoded by the NOL3 gene, is a unique multifunctional protein that serves as a potent inhibitor of programmed cell death [1][5]. Unlike most apoptosis regulators that target either the intrinsic or extrinsic pathway, ARC inhibits both by interacting with BAX and Caspase-8/FADD, respectively [2]. It is primarily expressed in terminally differentiated cells like cardiomyocytes and skeletal myocytes, where it provides vital protection against stress-induced death and ischemia-reperfusion injury [3]. In the context of oncology, ARC is frequently upregulated in various malignancies, where it promotes tumor cell survival and confers resistance to chemo- and radiotherapy [4]. Consequently, ARC is an attractive therapeutic target for sensitizing cancer cells to treatment, though its critical role in cardiac protection presents a significant challenge for systemic inhibition [3][4]. Current research efforts are focused on developing targeted inhibitors that can disrupt ARC's anti-apoptotic function specifically within tumor environments [4]. Citations: [1] UniProt Consortium. (2023). UniProtKB - O60936 (NOL3_HUMAN). [2] Jo, D. G., et al. (2004). "ARC directly interacts with Bax and inhibits Bax-mediated apoptosis." FEBS Letters. [3] Kung, G., et al. (2011). "ARC: a critical regulator of cardiomyocyte apoptosis and necrosis." Journal of Molecular and Cellular Cardiology. [4] Donai, M., et al. (2010). "ARC (apoptosis repressor with caspase recruitment domain) is expressed in human breast cancer." Cancer Letters. [5] NCBI Gene. (2023). Gene ID: 8996 (NOL3).

Other names

Nucleolar protein 3NOL3Muscle-enriched protein with CARDMYPNOPNOP30

ARC inhibits apoptosis by binding to the CARD domain of pro-caspases and the death domain of FADD, and by directly interacting with BAX to prevent its activation [1][2].