title: Eight cytochrome P450s catalyze vitamin D metabolism.
abstract: Vitamin D3 plays a central role in calcium and phosphate homeostasis and is essential for the proper development and maintenance of bone. To exert its biological activities, vitamin D3 has to receive enzymatic transformation to the active form, 1,25-dihydroxyvitamin D3. The first step is the 25-hydroxylation reaction in the liver that produces 25-hydroxyvitamin D3, the major circulating form of vitamin D3. The 25-hydroxylation reaction is the prerequisite step for the subsequent 1 alpha-hydroxylation and 24-hydroxylation reactions in the kidney. The 1 alpha-hydroxylation reaction produces the active form of vitamin D3, whereas 24-hydroxylation reaction leads to inactivation. Both reactions are strictly controlled by parathyroid hormone, 1,25-dihydroxyvitamin D3, and calcium in a reciprocal manner in the kidney. At present, six cytochrome P450s (CYP2C11, 27A1, 2D25, 2R1, 3A4, and 2J3) are found to exhibit vitamin D 25-hydroxylation activities, and CYP27B1 and CYP24 are proved to be 1 alpha-hydroxylase and 24-hydroxylase, respectively. The main focus of this review is to summarize the properties of individual P450 in light of their catalytic activities to understand their physiological significance.
authors.affiliation: Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan. ohyama@sci.hiroshima-u.ac.jp
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Ohyama
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Yamasaki
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000502:physiology; D002112:Calcifediol / Q000378:metabolism; D053493:Cholestanetriol 26-Monooxygenase; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry* / Q000502:physiology; D000072467:Cytochrome P450 Family 2; D006801:Humans; D007668:Kidney / Q000201:enzymology*; D008099:Liver / Q000201:enzymology*; D051379:Mice; D010105:Oxygenases / Q000502:physiology; D010281:Parathyroid Hormone / Q000378:metabolism; D051381:Rats; D039181:Steroid 16-alpha-Hydroxylase / Q000502:physiology; D013250:Steroid Hydroxylases / Q000502:physiology; D014807:Vitamin D / Q000378:metabolism*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; D003577:Cytochrome P-450 Enzyme System; D010105:Oxygenases; D013250:Steroid Hydroxylases; D001189:Aryl Hydrocarbon Hydroxylases; C450279:CYP2C11 protein, rat; C106098:Cyp2j3 protein, rat; D051544:Cytochrome P-450 CYP3A; D000072467:Cytochrome P450 Family 2; D039181:Steroid 16-alpha-Hydroxylase; C510163:CYP3A4 protein, human; C506831:CYP27A1 protein, human; D053493:Cholestanetriol 26-Monooxygenase; C506832:Cyp27a1 protein, mouse; D002112:Calcifediol