CYP27A1

Cytochrome P450, family 27, subfamily A, polypeptide 1
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 1MFX
Identifiers
Symbols	CYP27A1 ; CP27; CTX; CYP27
External IDs	OMIM: 606530 MGI: 88594 HomoloGene: 36040 ChEMBL: 5992 GeneCards: CYP27A1 Gene
EC number	1.14.13.15
Gene ontology Molecular function • iron ion binding • steroid hydroxylase activity • heme binding • vitamin D3 25-hydroxylase activity • cholesterol 26-hydroxylase activity • cholestanetriol 26-monooxygenase activity Cellular component • mitochondrial inner membrane • mitochondrial matrix Biological process • bile acid biosynthetic process • xenobiotic metabolic process • cholesterol metabolic process • bile acid metabolic process • sterol metabolic process • calcitriol biosynthetic process from calciol • small molecule metabolic process • oxidation-reduction process Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	1593	104086
Ensembl	ENSG00000135929	ENSMUSG00000026170
UniProt	Q02318	Q9DBG1
RefSeq (mRNA)	NM_000784	NM_024264
RefSeq (protein)	NP_000775	NP_077226
Location (UCSC)	Chr 2: 218.78 – 218.82 Mb	Chr 1: 74.71 – 74.74 Mb
PubMed search	[1]	[2]

CYP27A1 is a gene encoding a cytochrome P450 oxidase, and is commonly known as sterol 27-hydroxylase. This enzyme is located in many different tissues where it is found within the mitochondria. It is most prominently involved in the biosynthesis of bile acids.

Function

CYP27A1 participates in the degradation of cholesterol to bile acids in both the classic and acidic pathways. It is the initiating enzyme in the acidic pathway to bile acids, yielding oxysterols by introducing a hydroxyl group to the carbon at the 27 position in cholesterol. In the acidic pathway, it produces 27-hydroxycholesterol from cholesterol whereas in the classic or neutral pathway, it produces 3β-hydroxy-5-cholestenoic acid.

It is also involved in the metabolism of vitamin D₃.

While CYP27A1 is present in many different tissues, its function in these tissues is largely uncharacterized. In macrophages, 27-hydroxycholesterol generated by this enzyme may be helpful against the production of inflammatory factors associated with cardiovascular disease.

Clinical significance

Mutations in CYP27A1 are associated with cerebrotendineous xanthomatosis, a rare lipid storage disease.

Inhibitors of CYP27A1 may be effective as adjuvants in the treatment of ER-positive breast cancer due to inhibition of the production of 27-hydroxycholesterol (which has estrogenic actions and stimulates the growth of ER-positive breast cancer cells). Some marketed drugs that have been identified as CYP27A1 inhibitors include anastrozole, fadrozole, bicalutamide, dexmedetomidine, ravuconazole, and posaconazole.

Interactive pathway map

Click on genes, proteins and metabolites below to link to respective articles.

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|{{{bSize}}}px|alt=Vitamin D Synthesis Pathway edit]]

File:VitaminDSynthesis WP1531.png

Vitamin D Synthesis Pathway edit

External links

• GeneReviews/NCBI/NIH/UW entry on Cerebrotendinous Xanthomatosis
• Cytochrome P-450 CYP27A1 at the US National Library of Medicine Medical Subject Headings (MeSH)