Cytochrome c oxidase subunit 2 (MT-CO2)

Cytochrome c oxidase subunit 2 (MT-CO2) is a mitochondrially encoded protein forming an essential structural and functional component of complex IV (cytochrome c oxidase) in the mitochondrial electron transport chain. MT-CO2 is anchored in the mitochondrial inner membrane and plays a central role in electron transfer from cytochrome c to the catalytic core, contributing to the reduction of molecular oxygen to water. This process is essential for generating the proton gradient that drives ATP synthesis through oxidative phosphorylation. Dysfunction or mutations in MT-CO2 can result in severe mitochondrial diseases with variable presentations, including mitochondrial encephalomyopathy, myopathy, lactic acidosis, and organ-specific or multisystem dysfunction. Rare mutations act by disrupting electron transport, reducing ATP production, and promoting excessive reactive oxygen species formation, with disease severity depending on the mutation type and load.

Other names

MT-CO2COX2COIICOXIIMTCO2CO2Cytochrome c oxidase polypeptide IIhCOX2

Not targeted by specific drugs for therapy; mechanistically, inhibition leads to respiratory chain blockade, impaired ATP production, and increased reactive oxygen species