Cytochrome c oxidase assembly factor 7

COA7 (Cytochrome c oxidase assembly factor 7) is a mitochondrial protein required for assembly of respiratory chain complexes I and IV, essential components of the electron transport chain (UniProt: Q96BR5). The protein functions in mitochondrial bioenergetics and is expressed in tissues with high energy demands. Mutations in COA7 are associated with spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 3 (SCAN3), a neurodegenerative disorder characterized by cerebellar atrophy and progressive motor dysfunction (UniProt: Q96BR5).

In Alzheimer's disease, COA7 is downregulated in post-mortem AD brain tissue compared to age-matched controls (mean log2FC: −0.51; Chaparral AD proteomics). This reduction was observed across subcellular fractions in TMT-labeled proteomics analysis. The downregulation of a key mitochondrial assembly factor in AD suggests potential impairment of respiratory chain biogenesis and oxidative phosphorylation capacity in affected neurons, consistent with documented mitochondrial dysfunction in Alzheimer's pathology.