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

Rat (10116)

Genome localization

5q12[25428 ],

Comments

A heme-thiolate protein (P-450).

Rate-limiting Description

"Preincubation of rat liver microsomes with iron (Fe)/ascorbate (50 microM/200 microM), known to induce peroxidation, resulted in a significant inhibition of (i) the rate-limiting enzyme in cholesterol biosynthesis, HMG-CoA reductase (46%, p < .01), (ii) the crucial enzyme controlling the conversion of cholesterol in bile acids, cholesterol 7alpha-hydroxylase (48%, p < .001), and (iii) the central enzyme for cholesterol esterification: Acyl-CoA:cholesterol acyltransferase (ACAT, 80%, p < .0001)." (10656290)

"The objective of this study was to investigate the mechanism of action of peroxisome proliferators and PPARalpha on the transcription of cholesterol 7alpha-hydroxylase, the rate-limiting enzyme in the conversion of cholesterol to bile acids in the liver." (10744771)

Regulatory Information

Upstream transcription factor

25735;25664;25747;58852;171302

Regulatory type

Detail

transcriptional level;

"This promotor region contains many liver-enriched or -specific elements (TGT3, HNF/LF-B1), putative hormone responsive elements (TRE, GRE, RRE or RARE) and ubiquitous transcription factor binding sites (NF-1, OCT-1). " (14522988)

transcriptional factor;PPARalpha(25747),PPARgamma(25664)

"The aim of this present study was to determine the effect of 1 on protein expression of PPARalpha/gamma and related target molecules such as CYP7A and DGAT protein expression in the liver of hyperlipidemic fatty liver (HFL) rats, and to investigate the possible mechanism of treating HFL. " (18696335)

transcriptional level;TGFbeta1(59086),TNFalpha(24835)

"TGFbeta1, TNFalpha, and insulin signaling crosstalk in regulation of the rat cholesterol 7alpha-hydroxylase gene expression. " (18511845)

transcriptional factor;HNF4alpha(25735)

"Activation of bile acid biosynthesis by the p38 mitogen-activated protein kinase (MAPK): hepatocyte nuclear factor-4alpha phosphorylation by the p38 MAPK is required for cholesterol 7alpha-hydroxylase expression. " (17603092)

transcriptional factor;"oxysterol receptor,liver X receptor alpha,LXRalpha(58852),bile acid receptor"

"The expression of cholesterol 7alpha-hydroxylase (CYP7alpha), the rate-limiting enzyme in the catabolism of cholesterol to bile acid, is stimulated by oxysterol receptor, liver X receptor alpha (LXRalpha) and negatively regulated by a bile acid receptor, farnesoid X receptor." (17054913)

transcriptional factor;Thyroid hormone receptor(24831,81812)

"We thus performed chromatin immunoprecipitation assays to investigate coactivator recruitment and histone acetylation patterns on the thyroid hormone response elements of four endogenous target genes (GH, sarcoplasmic endoplasmic reticulum calcium-adenosine triphosphatase, phosphoenolpyruvate carboxykinase, and cholesterol 7alpha-hydroxylase) in a rat pituitary cell line that expresses TRs." (16254015)

transcriptional factor;HNF-3(171302)

"HNF-3 was required for both basal transcriptional activity and stimulation of the rat CYP7A promoter activity by retinoic acid" (9799805)

Gene ontology

Gene ontology

GO:0009055 (F) electron carrier activity [P18125 ];
GO:0005792 (C) microsome [P18125 ];
GO:0055114 (P) oxidation reduction [P18125 ];
GO:0020037 (F) heme binding [P18125 ];
GO:0008123 (F) cholesterol 7-alpha-monooxygenase activity [P18125 ];
GO:0005506 (F) iron ion binding [P18125 ];
GO:0005789 (C) endoplasmic reticulum membrane [P18125 ];

Subcellular localization

Localization

endoplasmic reticulum [P18125 ];

microsome [P18125 ];

membrane [P18125 ];

Links

SwissProt

P18125

Entrez Gene

25428



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