Cholesterol 7 alpha-hydroxylase

Cholesterol 7 alpha-hydroxylase
Cytochrome P450, family 7, subfamily A, polypeptide 1

PDB rendering based on 3dax.
Identifiers
Symbols CYP7A1; CP7A; CYP7; CYPVII; MGC126826; MGC138389
External IDs OMIM118455 MGI106091 HomoloGene30987 GeneCards: CYP7A1 Gene
EC number 1.14.13.17
Orthologs
Species Human Mouse
Entrez 1581 13122
Ensembl ENSG00000167910 ENSMUSG00000028240
UniProt P22680 Q8BFR7
RefSeq (mRNA) NM_000780 NM_007824.2
RefSeq (protein) NP_000771 NP_031850.2
Location (UCSC) Chr 8:
59.4 – 59.41 Mb
Chr 4:
6.19 – 6.2 Mb
PubMed search [1] [2]

Cholesterol 7 alpha-hydroxylase also known as cholesterol 7-alpha-monooxygenase or cytochrome P450 7A1 (CYP7A1) is an enzyme that in humans is encoded by the CYP7A1 gene.[1]

Contents

Function

Cholesterol 7 alpha-hydroxylase is the rate-limiting enzyme in the synthesis of bile acid from cholesterol via the classic pathway, catalyzing the formation of 7-alpha-hydroxycholesterol. CYP7A1 is a cytochrome P450 heme enzyme that oxidizes cholesterol using molecular oxygen.

It is downregulated by Sterol regulatory element-binding proteins (SREBP) when plasma cholesterol levels are low. It is upregulated by the nuclear receptor LXR (liver X receptor) when cholesterol (to be specific, oxysterol) levels are high.[2]

The effect of this upregulation is to increase the production of bile acids and reduce the level of cholesterol in hepatocytes.

Clinical significance

Deficiency of this enzyme will increase the possibility of cholesterol gallstones.[3]

References

  1. ^ Cohen JC, Cali JJ, Jelinek DF, Mehrabian M, Sparkes RS, Lusis AJ, Russell DW, Hobbs HH (September 1992). "Cloning of the human cholesterol 7 alpha-hydroxylase gene (CYP7) and localization to chromosome 8q11-q12". Genomics 14 (1): 153–61. doi:10.1016/S0888-7543(05)80298-8. PMID 1358792. 
  2. ^ Chawla A, Saez E, Evans RM (September 2000). "Don't know much bile-ology". Cell 103 (1): 1–4. doi:10.1016/S0092-8674(00)00097-0. PMID 11051540. 
  3. ^ Paumgartner G, Sauerbruch T (November 1991). "Gallstones: pathogenesis". Lancet 338 (8775): 1117–21. doi:10.1016/0140-6736(91)91972-W. PMID 1682550. 

Further reading

External links


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