Cytochrome P450 2R1 (CYP2R1)

CYP2R1 encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This enzyme is a microsomal vitamin D hydroxylase that converts vitamin D into the active ligand for the vitamin D receptor. A mutation in this gene has been associated with selective 25-hydroxyvitamin D deficiency.The synthesis of bioactive vitamin D requires hydroxylation at the 25 and 1-alpha positions by cytochrome P450 enzymes in the liver and kidney, respectively. Vitamin D 25-hydroxylase catalyzes the first reaction and 25-hydroxyvitamin D3-1-alpha-hydroxylase (CYP27B1) catalyzes the second reaction.