Center for Bioinformatics
Oxidoreductases | Transferases | Hydrolases | Lyases | Isomerases | Ligases

Basic Information

Enzyme Number

1.14.13.17

Official Name

cholesterol 7alpha-monooxygenase

Name from literature

cholesterol 7alpha-hydroxylase

Pathway from literature

bile acid synthesis/the synthesis of the cofactor for PAH(phenylalanine hydroxylase )

Pathway from KEGG

Lipid Metabolism; Bile acid biosynthesis; map00120

Cellular Processes; Endocrine System; PPAR signaling pathway; map03320

Organisms

Human (9606)

Genome localization

8q11-q12[1581 ],

Comments

A heme-thiolate protein (P-450).

Rate-limiting Description

"Studies involved measurements of specific activities of four enzymes participating in the maintenance of hepatic cholesterol metabolism: HMG-CoA-reductase, the rate limiting enzyme of cholesterol synthesis; cholesterol 7 alpha-hydroxylase, the rate limiting enzyme in bile acid synthesis; acyl CoA: cholesterol acyltransferase, the enzyme responsible for esterification of cholesterol; and cholesterol ester hydrolase (CEH), an enzyme which hydrolyzes cholesterol." (8258956)

"The cloned human oxysterol 7alpha-hydroxylase (CYP7B1) cDNA encodes a polypeptide of 506 amino acid residues that shares 40% sequence identity to human cholesterol 7alpha-hydroxylase (CYP7A1), the rate-limiting enzyme in the conversion of cholesterol to bile acids in the liver." (10588945)

Regulatory Information

Upstream transcription factor

2494;10062;2308;10891;3172;6720

Regulatory type

Detail

regulatory enzyme;

"We describe an accurate method for monitoring the enzymatic activity of hepatic cholesterol 7alpha-hydroxylase (C7alphaOH; CYP7A1), the rate-limiting and major regulatory enzyme in the synthesis of bile acids." (12562858#12235263)

transcriptional factor;"SREBP(6720),FOXO1(2308)"

"FOXO1 and SREBP-1c have roles in insulin regulation of cholesterol 7alpha-hydroxylase expression" (16885156#16885156)

transcriptional factor;liver receptor homolog-1(2494)

"The liver receptor homolog-1 has emerged as an essential regulator for the expression of CYP7A1." (15205472)

transcriptional factor;HNF-4alpha(3172)

"regulation by HNF-4alpha" (15796896)

transcriptional factor;TGFbeta(7040)

"TGFbeta1 represses CYP7A1 gene transcription in human hepatocytes by a mechanism involving Smad3-dependent inhibition of HNF4alpha and histone deacetylase remodeling of CYP7A1 chromatin." (17920062)

transcriptional factor;liver receptor homolog-1(2494)

"Liver receptor homolog 1 (LRH-1) is a key transcriptional factor required for the hepatic expression of CYP7A1." (18270374)

transcriptional factor;PGC-1alpha(10891)

"PGC-1alpha is an important co-activator for LRH-1 and that SHP targets the interaction between LRH-1 and PGC-1alpha to inhibit CYP7A1 expression." (18385139)

transcriptional factor;NR1H3(10062)

"we have found that certain natural 6alpha-hydroxylated bile acids are receptor-specific activators of nuclear liver X receptor alpha (LXRalpha) (NR1H3), a Nuclear receptor regulating the expression of the cholesterol 7alpha-hydroxylase gene, coding for the rate-limiting enzyme in the major pathway of bile acid synthesis" (10936612)

Gene ontology

Gene ontology

GO:0009055 (F) electron carrier activity [P22680 ];
GO:0005792 (C) microsome [P22680 ];
GO:0055114 (P) oxidation reduction [P22680 ];
GO:0020037 (F) heme binding [P22680 ];
GO:0008123 (F) cholesterol 7-alpha-monooxygenase activity [P22680 ];
GO:0005506 (F) iron ion binding [P22680 ];
GO:0005789 (C) endoplasmic reticulum membrane [P22680 ];

Subcellular localization

Localization

endoplasmic reticulum [P22680 ];

microsome [P22680 ];

membrane [P22680 ];

Links

SwissProt

P22680

Entrez Gene

1581

HPRD

00324



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  Last Modified: 2009-03-24  
  Design by Zhao Min