Cytochrome c oxidase subunit 5B, mitochondrial (COX5B)

Cytochrome c oxidase subunit 5B, mitochondrial (COX5B), is a nuclear-encoded protein subunit of the cytochrome c oxidase complex (Complex IV), the final enzyme of the mitochondrial respiratory chain[1][2][3][4][5]. COX5B is involved in the transfer of electrons from cytochrome c to molecular oxygen and in the generation of the proton gradient that drives ATP synthesis[1][2][3]. Although the core electron transfer and proton pumping are performed by mitochondrially encoded subunits, COX5B and other nuclear subunits are thought to regulate assembly, function, and stability of the enzyme complex[1][2][3]. COX5B is implicated in mitochondrial diseases when mutated or dysregulated, and altered subunit expression may have roles in redox regulation and metabolic adaptation of tumor cells[2][7]. No drugs are currently known to selectively target COX5B alone, but the cytochrome c oxidase complex is broadly inhibited by agents used experimentally or in toxicology[3][6].

Other names

Cytochrome c oxidase subunit 5BCOX5BCytochrome c oxidase polypeptide VbCOXVbcytochrome c oxidase subunit 5B, mitochondrialcytochrome c oxidase polypeptide VB, mitochondrialcytochrome c oxidase subunit Vbepididymis secretory sperm binding protein

Drugs inhibiting Complex IV block electron transfer from cytochrome c to oxygen, halting oxidative phosphorylation and ATP production. No evidence for selective activators or inhibitors specifically targeting COX5B subunit.