CYP8B1 (cytochrome P450, family 8, subfamily B, polypeptide 1) also known as sterol 12-alpha-hydroxylase is a protein which in humans is encoded by the CYP8B1 gene.[5]

CYP8B1
Identifiers
AliasesCYP8B1, CP8B, CYP12, cytochrome P450 family 8 subfamily B member 1
External IDsOMIM: 602172; MGI: 1338044; HomoloGene: 3233; GeneCards: CYP8B1; OMA:CYP8B1 - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_004391

NM_010012

RefSeq (protein)

NP_004382

NP_034142

Location (UCSC)Chr 3: 42.86 – 42.88 MbChr 9: 121.74 – 121.75 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

This gene 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.

CYP8B1 is an endoplasmic reticulum membrane protein and catalyzes the conversion of 7 alpha-hydroxy-4-cholesten-3-one into 7-alpha,12-alpha-dihydroxy-4-cholesten-3-one. The balance between these two steroids determines the relative amounts of the two primary bile acids, cholic acid and chenodeoxycholic acid, both of which are secreted in the bile. In the intestine these bile acids affect the solubility of cholesterol and other lipids, promoting their absorption.

CYP8B1 is unique among the cytochrome P450 genes in that it is intronless.[6]

The elephant, manatee and naked mole rat have inactive copies of this gene and lack cholic acid in their bile.[7] Relaxed selection resulting from changes in diet to consume less lipids might have contributed to the loss of this gene in several species.[8]

References

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  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000180432Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000050445Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ Gåfvels M, Olin M, Chowdhary BP, Raudsepp T, Andersson U, Persson B, Jansson M, Björkhem I, Eggertsen G (March 1999). "Structure and chromosomal assignment of the sterol 12alpha-hydroxylase gene (CYP8B1) in human and mouse: eukaryotic cytochrome P-450 gene devoid of introns". Genomics. 56 (2): 184–96. doi:10.1006/geno.1998.5606. PMID 10051404.
  6. ^   This article incorporates public domain material from "Entrez Gene: CYP8B1". Reference Sequence collection. National Center for Biotechnology Information.
  7. ^ Sharma, V; Hiller, M (1 December 2018). "Loss of Enzymes in the Bile Acid Synthesis Pathway Explains Differences in Bile Composition among Mammals". Genome Biology and Evolution. 10 (12): 3211–3217. doi:10.1093/gbe/evy243. PMC 6296402. PMID 30388264.
  8. ^ Shinde, SS; Teekas, L; Sharma, S; Vijay, N (September 2019). "Signatures of Relaxed Selection in the CYP8B1 Gene of Birds and Mammals". Journal of Molecular Evolution. 87 (7–8): 209–220. Bibcode:2019JMolE..87..209S. doi:10.1007/s00239-019-09903-6. PMID 31372666. S2CID 199380339.

Further reading

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This article incorporates text from the United States National Library of Medicine, which is in the public domain.