Atypical kinase involved in the biosynthesis of coenzyme Q, also named ubiquinone, an essential lipid-soluble electron transporter for aerobic cellular respiration ( , ). Its substrate specificity is unclear: does not show any protein kinase activity (, ). Probably acts as a small molecule kinase, possibly a lipid kinase that phosphorylates a prenyl lipid in the ubiquinone biosynthesis pathway, as suggested by its ability to bind coenzyme Q lipid intermediates (, ). Shows an unusual selectivity for binding ADP over ATP .
Subcellular locations: Mitochondrion, Membrane
Widely expressed, with highest levels in adrenal gland, heart, pancreas, nasal mucosa, stomach, uterus and skeletal muscle.