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25-Hydroxyvitamin D3 1-alpha-hydroxylase

25-Hydroxyvitamin D3 1-alpha-hydroxylase (VD3 1A hydroxylase) also known as cytochrome p450 27B1 (CYP27B1) or simply 1-alpha-hydroxylase is a cytochrome P450 enzyme that in humans is encoded by the CYP27B1 gene.[1][2][3]

VD3 1A hydroxylase is located in the proximal tubule of the kidney and a variety of other tissues, including skin (keratinocytes), immune cells,[4] and bone (osteoblasts).[5] The enzyme catalyzes the hydroxylation of Calcifediol to calcitriol (the bioactive form of Vitamin D):[6]

calcidiol + 2 reduced adrenodoxin + 2 H+ + O2 ⇌ calcitriol + 2 oxidized adrenodoxin + H2O

Interactive pathway map

Click on genes, proteins and metabolites below to link to respective articles. [§ 1]

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Vitamin D Synthesis Pathway (view / edit)
  1. The interactive pathway map can be edited at WikiPathways: “VitaminDSynthesis_WP1531”.

References

  1. “Entrez Gene: cytochrome P450”.
  2. Takeyama K, Kitanaka S, Sato T, Kobori M, Yanagisawa J, Kato S (Sep 1997). “25-Hydroxyvitamin D3 1alpha-hydroxylase and vitamin D synthesis”. Science. 277 (5333): 1827–30. doi:10.1126/science.277.5333.1827. PMID 9295274.
  3. Monkawa T, Yoshida T, Wakino S, Shinki T, Anazawa H, Deluca HF, Suda T, Hayashi M, Saruta T (Oct 1997). “Molecular cloning of cDNA and genomic DNA for human 25-hydroxyvitamin D3 1 alpha-hydroxylase”. Biochemical and Biophysical Research Communications. 239 (2): 527–33. doi:10.1006/bbrc.1997.7508. PMID 9344864.
  4. Sigmundsdottir H, Pan J, Debes GF, Alt C, Habtezion A, Soler D, Butcher EC (Mar 2007). “DCs metabolize sunlight-induced vitamin D3 to ‘program’ T cell attraction to the epidermal chemokine CCL27” (PDF). Nature Immunology. 8 (3): 285–93. doi:10.1038/ni1433. PMID 17259988.
  5. Kogawa M, Findlay DM, Anderson PH, Ormsby R, Vincent C, Morris HA, Atkins GJ (Oct 2010). “Osteoclastic metabolism of 25(OH)-vitamin D3: a potential mechanism for optimization of bone resorption”. Endocrinology. 151 (10): 4613–25. doi:10.1210/en.2010-0334. PMID 20739402.
  6. Gray RW, Omdahl JL, Ghazarian JG, DeLuca HF (Dec 1972). “25-Hydroxycholecalciferol-1-hydroxylase. Subcellular location and properties”. The Journal of Biological Chemistry. 247 (23): 7528–32. PMID 4404596.

Further reading

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