Contents

25-Hydroxyvitamin D 1-alpha-hydroxylase

Mammalian protein found in Homo sapiens

CYP27B1
Identifiers
Aliases	CYP27B1, CP2B, CYP1, CYP1alpha, CYP27B, P450c1, PDDR, VDD1, VDDR, VDDRI, VDR, cytochrome P450 family 27 subfamily B member 1
External IDs	OMIM: 609506; MGI: 1098274; HomoloGene: 37139; GeneCards: CYP27B1; OMA:CYP27B1 - orthologs
EC number	1.14.15.18
Gene location (Human) Chr. Chromosome 12 (human)[1] Band 12q14.1 Start 57,762,334 bp[1] End 57,768,986 bp[1]
Gene location (Mouse) Chr. Chromosome 10 (mouse)[2] Band 10|10 D3 Start 126,884,119 bp[2] End 126,888,875 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in kidney tubule metanephric glomerulus body of pancreas hair follicle right lobe of thyroid gland left lobe of thyroid gland left adrenal gland human kidney left adrenal cortex right adrenal gland Top expressed in morula right kidney embryo Convoluted tubule embryo proximal convoluted tubule lip human kidney uterus spermatocyte More reference expression data BioGPS n/a
Gene ontology Molecular function iron ion binding metal ion binding monooxygenase activity heme binding oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen oxidoreductase activity calcidiol 1-monooxygenase activity Cellular component cytoplasm membrane mitochondrial membranes mitochondrial outer membrane mitochondrion Biological process bone mineralization response to vitamin D calcium ion homeostasis response to interferon-gamma vitamin D metabolic process regulation of bone mineralization positive regulation of keratinocyte differentiation G1 to G0 transition response to estrogen response to lipopolysaccharide negative regulation of calcidiol 1-monooxygenase activity decidualization vitamin metabolic process negative regulation of cell growth calcitriol biosynthetic process from calciol positive regulation of vitamin D 24-hydroxylase activity vitamin D catabolic process positive regulation of vitamin D receptor signaling pathway calcium ion transport negative regulation of cell population proliferation Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 1594 13115 Ensembl ENSG00000111012 ENSMUSG00000006724 UniProt O15528 O35084 RefSeq (mRNA) NM_000785 NM_010009 RefSeq (protein) NP_000776 NP_034139 Location (UCSC) Chr 12: 57.76 – 57.77 Mb Chr 10: 126.88 – 126.89 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

25-Hydroxyvitamin D 1-alpha-hydroxylase (VD 1A hydroxylase) also known as calcidiol 1-monooxygenase ^[5]orcytochrome p450 27B1 (CYP27B1) or simply 1-alpha-hydroxylase is a cytochrome P450 enzyme that in humans is encoded by the CYP27B1 gene.^[6][7][8]

VD 1A hydroxylase is located in the proximal tubule of the kidney and a variety of other tissues, including skin (keratinocytes), immune cells,^[9] and bone (osteoblasts).^[10]

Reactions[edit]

The enzyme catalyzes the hydroxylationofcalcifedioltocalcitriol (the bioactive form of Vitamin D):^[11]

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

The enzyme is also able to oxidize ercalcidiol (25-OH D2) to ercalcitriol, secalciferol to calcitetrol, and 25-hydroxy-24-oxocalciol to (1S)-1,25-dihydroxy-24-oxocalciol.^[12]

• 
  Calcidiol
• 
  Calcitriol

Clinical significance[edit]

Loss-of-function mutations in CYP27B1 cause Vitamin D-dependent rickets, type IA.^[13]

Interactive pathway map[edit]

[[File:

[[

]]

[[

]]

[[

]]

[[

]]

References[edit]

Further reading[edit]

External links[edit]

• 25-Hydroxyvitamin+D3+1-alpha-Hydroxylase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
• Human CYP27B1 genome location and CYP27B1 gene details page in the UCSC Genome Browser.
• Human VDR genome location and VDR gene details page in the UCSC Genome Browser.