Cytochrome c oxidase subunit 1 (MT-CO1)

Cytochrome c oxidase subunit 1 (MT-CO1) is the catalytic core subunit of cytochrome c oxidase (Complex IV), the last enzyme complex of the mitochondrial respiratory electron transport chain in eukaryotes[1][5][3]. MT-CO1 is encoded by the mitochondrial genome and is critical for oxidative phosphorylation, reducing oxygen to water and enabling ATP synthesis by creating a proton gradient across the mitochondrial inner membrane[1][5]. Expression and functional integrity of MT-CO1 are necessary for energy metabolism and normal cellular function; mutations or deficiency can result in diverse mitochondrial disorders, neurodegenerative and cardiovascular diseases, and play a role in cancer biology, particularly in the colon[1][5]. The MT-CO1 gene is also widely used as a DNA barcoding marker for species identification due to sequence conservation within species and between-species variability[1][2]. No small molecule drugs specifically target MT-CO1 clinically; however, inhibitors of the cytochrome c oxidase complex (e.g., cyanide, carbon monoxide) act via binding to the complex at or near the heme/copper centers for research or as environmental toxins[1][5]. Loss-of-function or pathogenic variants are useful as genetic and protein biomarkers in diagnosis and research related to mitochondrial diseases and some cancer types[1]. Targeting or inhibiting this subunit pharmacologically carries severe safety risks due to its essential, ubiquitous role in ATP production and cell survival[5].

Other names

Cytochrome c oxidase subunit ICOICOXICOX1MTCO1Cytochrome c oxidase polypeptide ICCOI

Inhibition of electron transfer (for example, by respiratory chain inhibitors—cyanide, carbon monoxide—affect whole complex, not subunit-specific)