COQ8B
Domain
Adopts an atypical protein kinase-like fold: while it adopts a core fold similar to that of well-characterized protein kinase-like domains. The KxGQ motif completely occludes the typical substrate binding pocket. Nucleotide-binding opens the substrate binding pocket and flips the active site from inside the hydrophobic core into a catalytically competent, solvent-exposed posture.
Function
Atypical kinase involved in the biosynthesis of coenzyme Q, also named ubiquinone, an essential lipid-soluble electron transporter for aerobic cellular respiration (PubMed:24270420). 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. Required for podocyte migration (PubMed:24270420).
Involvement in disease
Nephrotic syndrome 9
NPHS9
A form of nephrotic syndrome, a renal disease clinically characterized by progressive renal failure, severe proteinuria, hypoalbuminemia, hyperlipidemia and edema. Kidney biopsies show focal segmental glomerulosclerosis.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the protein kinase superfamily. ADCK protein kinase family.
Tissue Specificity
Widely expressed, including renal podocytes.
Cellular localization
- Mitochondrion membrane
- Single-pass membrane protein
- Cytoplasm
- Cytosol
- Cell membrane
Alternative names
ADCK4, COQ8B, AarF domain-containing protein kinase 4, Coenzyme Q protein 8B