Vitamin D 25-hydroxylase
Function
A cytochrome P450 monooxygenase involved in activation of vitamin D precursors. Catalyzes hydroxylation at C-25 of both forms of vitamin D, vitamin D(2) and D(3) (calciol) (PubMed:12867411, PubMed:15465040, PubMed:18511070). Can metabolize vitamin D analogs/prodrugs 1alpha-hydroxyvitamin D(2) (doxercalciferol) and 1alpha-hydroxyvitamin D(3) (alfacalcidol) forming 25-hydroxy derivatives (PubMed:15465040, PubMed:18511070). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (CPR; NADPH-ferrihemoprotein reductase) (PubMed:12867411, PubMed:15465040, PubMed:18511070).
Involvement in disease
Rickets vitamin D-dependent 1B
VDDR1B
An autosomal recessive disorder caused by a selective deficiency of the active form of vitamin D (1,25-dihydroxyvitamin D3) and resulting in defective bone mineralization and clinical features of rickets. The patients sera have low calcium concentrations, low phosphate concentrations, elevated alkaline phosphatase activity and low levels of 25-hydroxyvitamin D.
None
The disease is caused by variants affecting the gene represented in this entry.
Pathway
Hormone biosynthesis; vitamin D biosynthesis.
Sequence Similarities
Belongs to the cytochrome P450 family.
Cellular localization
- Endoplasmic reticulum membrane
- Peripheral membrane protein
- Microsome membrane
- Peripheral membrane protein
Alternative names
Vitamin D 25-hydroxylase, Cytochrome P450 2R1, CYP2R1