Cx9C motif-containing protein 4 (CMC4)

Cx9C motif-containing protein 4 (CMC4) is a small cysteine-rich mitochondrial protein characterized by the presence of a distinctive twin CX9C motif—a conserved pattern of cysteine residues spaced by nine amino acids that is implicated in the stabilization of a coiled-coil structure[2][3]. CMC4 localizes to the mitochondrial inner membrane, facing the intermembrane space, where it is involved in the correct assembly of cytochrome c oxidase (COX), a crucial component of the mitochondrial electron transport chain[1][6]. By binding copper(I) ions, CMC4 is thought to play an important role in copper trafficking and homeostasis within mitochondria, impacting both COX activity and other mitochondrial enzymes such as superoxide dismutase (SOD1)[1]. In humans, the gene is designated CMC4 (HGNC symbol: 35428; UniProt: P56277) and has been implicated in complex chromosomal rearrangements associated with certain hematologic malignancies, notably mature T-cell proliferations involving t(X;14) translocations[4]. Although not established as a therapeutic drug target, alterations or mutations in CMC4 have associations with diseases such as Moyamoya disease 1 and Rhabdomyolysis-myalgia syndrome[4]. At present, no drugs are known to interact specifically with this protein, and established clinical biomarkers or direct safety concerns are not documented in the literature[6][4][1].

Other names

MTCP1NBC6.1BMTCP1MTCP-1 type Ap8MTCP1P8MTCP1p8Mature T-cell proliferation 1 neighbor proteinMature T-cell proliferation-1 type AProtein p8 MTCP-1mature T-cell proliferation 1, isoform p8cx9C motif-containing protein 4C-x(9)-C motif containing 4 homolog