Cytochrome c oxidase subunit 5A, mitochondrial (COX5A) (COX5A)

Cytochrome c oxidase subunit 5A (COX5A), also known as mitochondrial respiratory chain complex IV subunit Va, is a nuclear-encoded protein that forms an essential part of the terminal enzyme in the mitochondrial electron transport chain (UniProt, Wikipedia). It catalyzes the reduction of oxygen to water, a process coupled with proton pumping to generate the electrochemical gradient required for ATP synthesis (NCBI Gene, Wikipedia). Beyond its fundamental role in cellular bioenergetics, COX5A is a key regulator of metabolic reprogramming in various cancers, where its upregulation promotes tumor progression, migration, and invasion through the activation of the PI3K/Akt and ERK1/2 signaling pathways (PubMed, Journal of Cellular and Molecular Medicine). In cardiovascular and regenerative medicine, COX5A is recognized for its protective role against oxidative stress and apoptosis, with research highlighting its potential as a target for mitigating doxorubicin-induced cardiotoxicity and rejuvenating aged hematopoietic stem cells using compounds like peanut procyanidin A (PubMed, Aging and Disease). Mutations in the COX5A gene are linked to severe mitochondrial disorders, such as Leigh syndrome and complex IV deficiency, characterized by lactic acidosis and multi-organ failure (UniProt, GeneCards). Consequently, COX5A represents a versatile therapeutic target, with strategies ranging from its inhibition in oncology to its stabilization or upregulation in metabolic and degenerative diseases (Frontiers in Pharmacology, PubMed).

Other names

COX-VACytochrome c oxidase polypeptide VaCytochrome c oxidase subunit VaMitochondrial respiratory chain complex IV subunit VaMC4DN20

COX5A facilitates the assembly and activity of mitochondrial complex IV, enabling the final step of the electron transport chain. Drugs and compounds targeting COX5A modulate ATP production, regulate mitochondrial reactive oxygen species (ROS) levels, and influence downstream oncogenic signaling pathways such as PI3K/Akt and ERK1/2. Classic inhibitors like cyanide and azide bind to the complex to halt aerobic respiration.