Atlas of Genetics and Cytogenetics in Oncology and Haematology

Home   Genes   Leukemias   Solid Tumors   Cancer-Prone   Deep Insight   Case Reports   Journals  Portal   Teaching   

X Y 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 NA

CYP7A1 (cytochrome P450, family 7, subfamily A, polypeptide 1)

Written2010-01Maria Norlin, Kjell Wikvall
Department of Pharmaceutical Biosciences, Division of Biochemistry, University of Uppsala, Uppsala, Sweden

(Note : for Links provided by Atlas : click)


cytochrome P450, subfamily VIIA (cholesterol 7 alpha-monooxygenase), polypeptide 1
cytochrome P450, family 7, subfamily A, polypeptide 1
Other aliasCP7A
HGNC (Hugo) CYP7A1
LocusID (NCBI) 1581
Atlas_Id 40254
Location 8q12.1  [Link to chromosome band 8q12]
Location_base_pair Starts at 58490178 and ends at 58500161 bp from pter ( according to hg19-Feb_2009)  [Mapping CYP7A1.png]
Fusion genes
(updated 2017)
Data from Atlas, Mitelman, Cosmic Fusion, Fusion Cancer, TCGA fusion databases with official HUGO symbols (see references in chromosomal bands)
Note CYP7A1 catalyzes 7alpha-hydroxylation of cholesterol, the major rate-limiting step in bile acid biosynthesis. The enzyme also converts cholestanol and several oxysterols into their 7alpha-hydroxylated products (Norlin and Wikvall, 2007).


Description The human CYP7A1 DNA maps to NM_000780 (Entrez Gene) and spans a region of 9.98 kB. CYP7A1 is located on chromosome 8 and consists of six exons.
Transcription The full length CYP7A1 mRNA is 2,875 bp with an open reading frame of 1,512 bp (Noshiro and Okuda, 1990).
Pseudogene No pseudogenes reported.


Description The human CYP7A1 protein consists of 504 amino acids and has a molecular weight of 57,630 Da (Noshiro and Okuda, 1990). Human CYP7A1 shares 40% sequence identity with CYP7B1, the other member of the CYP7 family.
Expression Most reports indicate exclusive liver specific expression. One study reports expression of CYP7A1 also in human prostate (Steckelbroeck et al., 2002). The expression of hepatic CYP7A1 in several species has been reported to be low in early life and to increase severalfold with age (Norlin, 2002; Massimi et al., 1998).
Localisation CYP7A1 is a endoplasmic reticulum membrane enzyme.
Function CYP7A1 is a cholesterol 7alpha-hydroxylase, catalyzing the first and rate-limiting step in the neutral or classic pathway for bile acid biosynthesis. Bile acid biosynthesis is the predominant pathway for cholesterol catabolism. The enzyme also 7alpha-hydroxylates 27-hydroxycholesterol and other oxysterols (Norlin et al., 2000a, b). Results supporting a role for CYP7A1 as an oxysterol 7alpha-hydroxylase are also reported by others (Dueland et al., 1992; Pandak et al., 2002). Studies on mice with a disruption in the Cyp7a1 gene (Ishibashi et al., 1996; Schwarz et al., 1996) demonstrated a crucial role for this enzyme in bile acid biosynthesis. Mice and humans with cholesterol 7alpha-hydroxylase deficiency exhibit, however, different phenotypes (Norlin and Wikvall, 2007).
Several mechanisms for regulation of CYP7A1 have been described (Chiang, 2004). Bile acids inhibit CYP7A1 gene transcription via negative feedback control. The feedback inhibition by bile acids involve several nuclear receptors such as liver receptor homolog 1 (LRH-1), hepatocyte nuclear factor 4alpha (HNF4alpha), small heterodimer partner (SHP) and the bile acid receptor farnesyl X receptor (FXR). Also the pregnane X receptor (PXR) and the vitamin D receptor (VDR) have been identified as bile acid-activated receptors (Staudinger et al., 2001; Han and Chiang, 2009). Bile acids are also reported to suppress CYP7A1 via stimulation of inflammatory cytokines (tumor necrosis factor alpha and IL-1beta) and mitogen-activated protein kinase (MAPK) signaling pathways leading to the activation of cJun N-terminus kinase (JNK). JNK may phosphorylate and inactivate transcription factors crucial for stimulating the hepatic expression of CYP7A1 (Chiang, 2004; Gupta et al., 2004). Cholestyramine, a drug used in the treatment of hyperlipoproteinemia, induces cholesterol 7alpha-hydroxylase by binding to bile acids in the intestine and preventing their reabsorption to the liver (Brown and Boyd, 1974). Evidence for a posttranscriptional regulation of cholesterol 7alpha-hydroxylase has been reported, but most of the data available suggest that the regulation is predominantly on a transcriptional level (Chiang, 2004; Stroup and Ramsaran, 2005).
Homology The CYP7A1 gene is conserved in many species, such as chimpanzee, dog, cow, mouse, rat, chicken, and zebrafish.


Germinal A metabolic disorder presenting with elevated plasma cholesterol levels caused by a homozygous deletion mutation in the CYP7A1 gene in a family of English and Celtic origin has been described (Pullinger et al., 2002). The mutation leads to a frameshift resulting in the synthesis of a truncated protein with no enzymatic activity. High levels of LDL cholesterol were seen in three homozygous subjects. The high levels of LDL cholesterol in the CYP7A1-deficient subjects were found to be resistant to treatment with hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors. Two male subjects had hypertriglyceridemia and premature gallstone disease. One subject had premature coronary and peripheral vascular disease. Individuals that are heterozygous for the mutation were also found to be hyperlipidemic, indicating that the disorder is inherited in a codominant fashion (Pullinger et al., 2002). The authors concluded that CYP7A1 deficiency in humans causes hypercholesterolemia. This conclusion is consistent with studies showing an association between cholesterol levels and polymorphisms at the CYP7A1 locus (Wang et al., 1998; Couture et al., 1999).

Implicated in

Entity Gallbladder cancer
Note CYP7A1 promoter polymorphism has been reported to be a genetic risk factor for gallbladder cancer. The association of the polymorphism with gallbladder cancer was more pronounced in female patients, and also in cancer patients who developed gallbladder cancer at advanced age (Srivastava et al., 2008).
Entity Colorectal cancer
Note A link between genetic polymorphism of CYP7A1 and decreased risk of colorectal adenomas has been reported (Tabata et al., 2006). Bile acids have long been implicated in colorectal carcinogenesis. The CC genotype of the CYP7A1 A-203C polymorphism was associated with a decreased risk of proximal colon adenomas. The findings provide further evidence for the role of bile acids in colorectal carcinogenesis. The polymorphism of the CYP7A1 gene probably leads to lower activity of the enzyme synthesizing bile acids (Tabata et al., 2006).
Entity Hypercholesterolemia/hyperlipidemia
Note Due to its important regulatory role in cholesterol catabolism, decreased CYP7A1 levels may lead to hypercholesterolemia. Indeed, high cholesterol levels were seen in subjects having a frameshift mutation in the CYP7A1 gene resulting in the synthesis of a non-functional enzyme. The hypercholesterolemia were resistant to treatment with HMG-CoA reductase inhibitors. Two of the three subjects that were homozygous for this mutation also had elevated plasma triglyceride levels. Six individuals, heterozygous for the mutation were also found to have hypercholesterolemia (Pullinger et al, 2002). An association between plasma cholesterol levels and polymorphisms at the CYP7A1 locus have been shown in some reports (Wang et al., 1998; Couture et al., 1999) whereas another study reported that common polymorphisms in the CYP7A1 gene do not contribute to variations in plasma LDL concentrations (Abrahamsson et al., 2005).
Entity Atherosclerosis
Note One subject with the frameshift mutation in the CYP7A1 gene (as described above) had premature coronary and peripheral vascular disease (Pullinger et al., 2002). Polymorphism in the CYP7A1 gene has been reported to be associated with subclinical atherosclerosis including the presence of atherosclerotic plaques in postmenopausal women (Lambrinoudaki et al., 2008). CYP7A1 polymorphism has also been reported to increase the progression of atherosclerosis and the risk of new clinical events in male patients (Hofman et al., 2005).


Common polymorphisms in the CYP7A1 gene do not contribute to variation in rates of bile acid synthesis and plasma LDL cholesterol concentration.
Abrahamsson A, Krapivner S, Gustafsson U, Muhrbeck O, Eggertsen G, Johansson I, Persson I, Angelin B, Ingelman-Sundberg M, Bjorkhem I, Einarsson C, van't Hooft FM.
Atherosclerosis. 2005 Sep;182(1):37-45. Epub 2005 Mar 3.
PMID 16115473
The specificity of the rat-liver cholesterol 7alpha-hydroxylase.
Brown MJ, Boyd GS.
Eur J Biochem. 1974 May 2;44(1):37-47.
PMID 4153147
Regulation of bile acid synthesis: pathways, nuclear receptors, and mechanisms.
Chiang JY.
J Hepatol. 2004 Mar;40(3):539-51. (REVIEW)
PMID 15123373
Association of the A-204C polymorphism in the cholesterol 7alpha-hydroxylase gene with variations in plasma low density lipoprotein cholesterol levels in the Framingham Offspring Study.
Couture P, Otvos JD, Cupples LA, Wilson PW, Schaefer EJ, Ordovas JM.
J Lipid Res. 1999 Oct;40(10):1883-9.
PMID 10508208
Expression of 7 alpha-hydroxylase in non-hepatic cells results in liver phenotypic resistance of the low density lipoprotein receptor to cholesterol repression.
Dueland S, Trawick JD, Nenseter MS, MacPhee AA, Davis RA.
J Biol Chem. 1992 Nov 15;267(32):22695-8.
PMID 1429619
Deoxycholic acid activates the c-Jun N-terminal kinase pathway via FAS receptor activation in primary hepatocytes. Role of acidic sphingomyelinase-mediated ceramide generation in FAS receptor activation.
Gupta S, Natarajan R, Payne SG, Studer EJ, Spiegel S, Dent P, Hylemon PB.
J Biol Chem. 2004 Feb 13;279(7):5821-8. Epub 2003 Dec 2.
PMID 14660582
Mechanism of vitamin D receptor inhibition of cholesterol 7alpha-hydroxylase gene transcription in human hepatocytes.
Han S, Chiang JY.
Drug Metab Dispos. 2009 Mar;37(3):469-78. Epub 2008 Dec 23.
PMID 19106115
Genetic variation in the rate-limiting enzyme in cholesterol catabolism (cholesterol 7alpha-hydroxylase) influences the progression of atherosclerosis and risk of new clinical events.
Hofman MK, Princen HM, Zwinderman AH, Jukema JW.
Clin Sci (Lond). 2005 Jun;108(6):539-45.
PMID 15707388
Disruption of cholesterol 7alpha-hydroxylase gene in mice. I. Postnatal lethality reversed by bile acid and vitamin supplementation.
Ishibashi S, Schwarz M, Frykman PK, Herz J, Russell DW.
J Biol Chem. 1996 Jul 26;271(30):18017-23.
PMID 8663429
Methylenetetrahydrofolate reductase C677T polymorphism is associated with central adiposity and increased androgenicity in healthy postmenopausal women.
Lambrinoudaki I, Kaparos G, Papadimitriou D, Sergentanis TN, Creatsa M, Alexandrou A, Logothetis E, Christodoulakos G, Kouskouni E.
Eur J Endocrinol. 2008 Sep;159(3):233-41.
PMID 18728123
Cholesterol 7alpha-hydroxylase (CYP7A): patterns of messenger RNA expression during rat liver development.
Massimi M, Lear SR, Huling SL, Jones AL, Erickson SK.
Hepatology. 1998 Oct;28(4):1064-72.
PMID 9755244
Oxysterol 7 alpha-hydroxylase activity by cholesterol 7 alpha-hydroxylase (CYP7A).
Norlin M, Andersson U, Bjorkhem I, Wikvall K.
J Biol Chem. 2000a Nov 3;275(44):34046-53.
PMID 10882719
24-hydroxycholesterol is a substrate for hepatic cholesterol 7alpha-hydroxylase (CYP7A).
Norlin M, Toll A, Bjorkhem I, Wikvall K.
J Lipid Res. 2000b Oct;41(10):1629-39.
PMID 11013305
Enzymes in the conversion of cholesterol into bile acids.
Norlin M, Wikvall K.
Curr Mol Med. 2007 Mar;7(2):199-218.
PMID 17346171
Expression of key enzymes in bile acid biosynthesis during development: CYP7B1-mediated activities show tissue-specific differences.
Norlin M.
J Lipid Res. 2002 May;43(5):721-31.
PMID 11971943
Molecular cloning and sequence analysis of cDNA encoding human cholesterol 7 alpha-hydroxylase.
Noshiro M, Okuda K.
FEBS Lett. 1990 Jul 30;268(1):137-40.
PMID 2384150
Regulation of oxysterol 7alpha-hydroxylase (CYP7B1) in primary cultures of rat hepatocytes.
Pandak WM, Hylemon PB, Ren S, Marques D, Gil G, Redford K, Mallonee D, Vlahcevic ZR.
Hepatology. 2002 Jun;35(6):1400-8.
PMID 12029625
Human cholesterol 7alpha-hydroxylase (CYP7A1) deficiency has a hypercholesterolemic phenotype.
Pullinger CR, Eng C, Salen G, Shefer S, Batta AK, Erickson SK, Verhagen A, Rivera CR, Mulvihill SJ, Malloy MJ, Kane JP.
J Clin Invest. 2002 Jul;110(1):109-17.
PMID 12093894
Disruption of cholesterol 7alpha-hydroxylase gene in mice. II. Bile acid deficiency is overcome by induction of oxysterol 7alpha-hydroxylase.
Schwarz M, Lund EG, Setchell KD, Kayden HJ, Zerwekh JE, Bjorkhem I, Herz J, Russell DW.
J Biol Chem. 1996 Jul 26;271(30):18024-31.
PMID 8663430
Role of genetic variant A-204C of cholesterol 7alpha-hydroxylase (CYP7A1) in susceptibility to gallbladder cancer.
Srivastava A, Pandey SN, Choudhuri G, Mittal B.
Mol Genet Metab. 2008 May;94(1):83-9. Epub 2008 Feb 21.
PMID 18178499
The nuclear receptor PXR is a lithocholic acid sensor that protects against liver toxicity.
Staudinger JL, Goodwin B, Jones SA, Hawkins-Brown D, MacKenzie KI, LaTour A, Liu Y, Klaassen CD, Brown KK, Reinhard J, Willson TM, Koller BH, Kliewer SA.
Proc Natl Acad Sci U S A. 2001 Mar 13;98(6):3369-74.
PMID 11248085
Characterization of the dehydroepiandrosterone (DHEA) metabolism via oxysterol 7alpha-hydroxylase and 17-ketosteroid reductase activity in the human brain.
Steckelbroeck S, Watzka M, Lutjohann D, Makiola P, Nassen A, Hans VH, Clusmann H, Reissinger A, Ludwig M, Siekmann L, Klingmuller D.
J Neurochem. 2002 Nov;83(3):713-26.
PMID 12390533
Cholesterol 7alpha-hydroxylase is phosphorylated at multiple amino acids.
Stroup D, Ramsaran JR.
Biochem Biophys Res Commun. 2005 Apr 15;329(3):957-65.
PMID 15752749
Genetic polymorphism of cholesterol 7alpha-hydroxylase (CYP7A1) and colorectal adenomas: Self Defense Forces Health Study.
Tabata S, Yin G, Ogawa S, Yamaguchi K, Mineshita M, Kono S.
Cancer Sci. 2006 May;97(5):406-10.
PMID 16630139
Linkage between cholesterol 7alpha-hydroxylase and high plasma low-density lipoprotein cholesterol concentrations.
Wang J, Freeman DJ, Grundy SM, Levine DM, Guerra R, Cohen JC.
J Clin Invest. 1998 Mar 15;101(6):1283-91.
PMID 9502769


This paper should be referenced as such :
Norlin, M ; Wikvall, K
CYP7A1 (cytochrome P450, family 7, subfamily A, polypeptide 1)
Atlas Genet Cytogenet Oncol Haematol. 2010;14(10):942-949.
Free journal version : [ pdf ]   [ DOI ]
On line version :

External links

HGNC (Hugo)CYP7A1   2651
Entrez_Gene (NCBI)CYP7A1  1581  cytochrome P450 family 7 subfamily A member 1
GeneCards (Weizmann)CYP7A1
Ensembl hg19 (Hinxton)ENSG00000167910 [Gene_View]
Ensembl hg38 (Hinxton)ENSG00000167910 [Gene_View]  ENSG00000167910 [Sequence]  chr8:58490178-58500161 [Contig_View]  CYP7A1 [Vega]
ICGC DataPortalENSG00000167910
TCGA cBioPortalCYP7A1
AceView (NCBI)CYP7A1
Genatlas (Paris)CYP7A1
SOURCE (Princeton)CYP7A1
Genetics Home Reference (NIH)CYP7A1
Genomic and cartography
GoldenPath hg38 (UCSC)CYP7A1  -     chr8:58490178-58500161 -  8q12.1   [Description]    (hg38-Dec_2013)
GoldenPath hg19 (UCSC)CYP7A1  -     8q12.1   [Description]    (hg19-Feb_2009)
EnsemblCYP7A1 - 8q12.1 [CytoView hg19]  CYP7A1 - 8q12.1 [CytoView hg38]
Mapping of homologs : NCBICYP7A1 [Mapview hg19]  CYP7A1 [Mapview hg38]
Gene and transcription
Genbank (Entrez)BC101777 BC112184 M93133 X56088
RefSeq transcript (Entrez)NM_000780
RefSeq genomic (Entrez)
Consensus coding sequences : CCDS (NCBI)CYP7A1
Cluster EST : UnigeneHs.1644 [ NCBI ]
CGAP (NCI)Hs.1644
Alternative Splicing GalleryENSG00000167910
Gene ExpressionCYP7A1 [ NCBI-GEO ]   CYP7A1 [ EBI - ARRAY_EXPRESS ]   CYP7A1 [ SEEK ]   CYP7A1 [ MEM ]
Gene Expression Viewer (FireBrowse)CYP7A1 [ Firebrowse - Broad ]
SOURCE (Princeton)Expression in : [Datasets]   [Normal Tissue Atlas]  [carcinoma Classsification]  [NCI60]
GenevestigatorExpression in : [tissues]  [cell-lines]  [cancer]  [perturbations]  
BioGPS (Tissue expression)1581
GTEX Portal (Tissue expression)CYP7A1
Human Protein AtlasENSG00000167910-CYP7A1 [pathology]   [cell]   [tissue]
Protein : pattern, domain, 3D structure
UniProt/SwissProtP22680   [function]  [subcellular_location]  [family_and_domains]  [pathology_and_biotech]  [ptm_processing]  [expression]  [interaction]
NextProtP22680  [Sequence]  [Exons]  [Medical]  [Publications]
With graphics : InterProP22680
Splice isoforms : SwissVarP22680
Domaine pattern : Prosite (Expaxy)CYTOCHROME_P450 (PS00086)   
Domains : Interpro (EBI)Cholesterol_7a_monooxygenase    Cyt_P450    Cyt_P450_CS    Cyt_P450_CYP7A1-type    Cyt_P450_E_grp-IV   
Domain families : Pfam (Sanger)p450 (PF00067)   
Domain families : Pfam (NCBI)pfam00067   
Conserved Domain (NCBI)CYP7A1
DMDM Disease mutations1581
Blocks (Seattle)CYP7A1
PDB (SRS)3DAX    3SN5    3V8D   
PDB (PDBSum)3DAX    3SN5    3V8D   
PDB (IMB)3DAX    3SN5    3V8D   
PDB (RSDB)3DAX    3SN5    3V8D   
Structural Biology KnowledgeBase3DAX    3SN5    3V8D   
SCOP (Structural Classification of Proteins)3DAX    3SN5    3V8D   
CATH (Classification of proteins structures)3DAX    3SN5    3V8D   
Human Protein Atlas [tissue]ENSG00000167910-CYP7A1 [tissue]
Peptide AtlasP22680
Protein Interaction databases
IntAct (EBI)P22680
Ontologies - Pathways
Ontology : AmiGOiron ion binding  endoplasmic reticulum membrane  bile acid biosynthetic process  bile acid biosynthetic process  bile acid biosynthetic process  bile acid biosynthetic process  cholesterol catabolic process  cholesterol 7-alpha-monooxygenase activity  cholesterol 7-alpha-monooxygenase activity  sterol metabolic process  regulation of lipid metabolic process  heme binding  organelle membrane  cholesterol homeostasis  intracellular membrane-bounded organelle  oxidation-reduction process  regulation of bile acid biosynthetic process  regulation of bile acid biosynthetic process  cellular response to glucose stimulus  cellular response to cholesterol  
Ontology : EGO-EBIiron ion binding  endoplasmic reticulum membrane  bile acid biosynthetic process  bile acid biosynthetic process  bile acid biosynthetic process  bile acid biosynthetic process  cholesterol catabolic process  cholesterol 7-alpha-monooxygenase activity  cholesterol 7-alpha-monooxygenase activity  sterol metabolic process  regulation of lipid metabolic process  heme binding  organelle membrane  cholesterol homeostasis  intracellular membrane-bounded organelle  oxidation-reduction process  regulation of bile acid biosynthetic process  regulation of bile acid biosynthetic process  cellular response to glucose stimulus  cellular response to cholesterol  
Pathways : KEGGPPAR signaling pathway    Bile acid biosynthesis   
REACTOMEP22680 [protein]
REACTOME PathwaysR-HSA-211976 [pathway]   
NDEx NetworkCYP7A1
Atlas of Cancer Signalling NetworkCYP7A1
Wikipedia pathwaysCYP7A1
Orthology - Evolution
GeneTree (enSembl)ENSG00000167910
Phylogenetic Trees/Animal Genes : TreeFamCYP7A1
Homologs : HomoloGeneCYP7A1
Homology/Alignments : Family Browser (UCSC)CYP7A1
Gene fusions - Rearrangements
Fusion : QuiverCYP7A1
Polymorphisms : SNP and Copy number variants
NCBI Variation ViewerCYP7A1 [hg38]
dbSNP Single Nucleotide Polymorphism (NCBI)CYP7A1
Exome Variant ServerCYP7A1
ExAC (Exome Aggregation Consortium)ENSG00000167910
GNOMAD BrowserENSG00000167910
Genetic variants : HAPMAP1581
Genomic Variants (DGV)CYP7A1 [DGVbeta]
DECIPHERCYP7A1 [patients]   [syndromes]   [variants]   [genes]  
CONAN: Copy Number AnalysisCYP7A1 
ICGC Data PortalCYP7A1 
TCGA Data PortalCYP7A1 
Broad Tumor PortalCYP7A1
OASIS PortalCYP7A1 [ Somatic mutations - Copy number]
Somatic Mutations in Cancer : COSMICCYP7A1  [overview]  [genome browser]  [tissue]  [distribution]  
Mutations and Diseases : HGMDCYP7A1
LOVD (Leiden Open Variation Database)Whole genome datasets
LOVD (Leiden Open Variation Database)LOVD - Leiden Open Variation Database
LOVD (Leiden Open Variation Database)LOVD 3.0 shared installation
BioMutasearch CYP7A1
DgiDB (Drug Gene Interaction Database)CYP7A1
DoCM (Curated mutations)CYP7A1 (select the gene name)
CIViC (Clinical Interpretations of Variants in Cancer)CYP7A1 (select a term)
NCG5 (London)CYP7A1
Cancer3DCYP7A1(select the gene name)
Impact of mutations[PolyPhen2] [SIFT Human Coding SNP] [Buck Institute : MutDB] [Mutation Assessor] [Mutanalyser]
Genetic Testing Registry CYP7A1
NextProtP22680 [Medical]
Target ValidationCYP7A1
Huge Navigator CYP7A1 [HugePedia]
snp3D : Map Gene to Disease1581
BioCentury BCIQCYP7A1
Clinical trials, drugs, therapy
Chemical/Protein Interactions : CTD1581
Chemical/Pharm GKB GenePA132
Clinical trialCYP7A1
canSAR (ICR)CYP7A1 (select the gene name)
PubMed115 Pubmed reference(s) in Entrez
GeneRIFsGene References Into Functions (Entrez)
REVIEW articlesautomatic search in PubMed
Last year publicationsautomatic search in PubMed

Search in all EBI   NCBI

© Atlas of Genetics and Cytogenetics in Oncology and Haematology
indexed on : Mon Jul 16 09:45:32 CEST 2018

Home   Genes   Leukemias   Solid Tumors   Cancer-Prone   Deep Insight   Case Reports   Journals  Portal   Teaching   

For comments and suggestions or contributions, please contact us