CABC1 (chaperone activity of bc1 complex-like), also known as COQ8 or ADCK3 (aarF domain-containing protein kinase 3) is a 647 amino acid mitochondrial protein that belongs to the protein kinase superfamily. Ubiquitously expressed with higher expression in heart and skeletal muscle, CABC1 is thought to function as a chaperone in the proper assembly of protein complexes found in the respiratory chain. CABC1 expression is induced both in response to DNA damage and by the tumor suppressor p53. When CABC1 expression is inhibited, p53-induced apoptosis is partially suppressed, suggesting a possible role for CABC1 in tumor suppression. Mutations in the gene encoding CABC1 may
be implicated in ubiquinone deficiency, which can lead to cerebellar ataxia and seizures. Four isoforms of CABC1 exist due to alternative splicing events.