Sterol-O-acyltransferase
| Sterol-O-acyltransferase | ||
|---|---|---|
| Mass / length primary structure | 550/522 amino acids | |
| Secondary to quaternary structure | multipass membrane protein (ER) | |
| Isoforms | 2 | |
| Identifier | ||
| Gene name (s) | SOAT1 , SOAT2 | |
| Enzyme classification | ||
| EC, category | 2.3.1.26 , transferase | |
| Response type | Esterification | |
| Substrate | Acyl-CoA + cholesterol | |
| Products | CoA + cholesterol ester | |
| Occurrence | ||
| Parent taxon | Eukaryotes | |
Sterol-O-acyltransferase (also: acyl-CoA-cholesterol-acyltransferase) is an enzyme in the endoplasmic reticulum of animals that catalyzes the esterification of cholesterol and fatty acids to cholesterol esters . From acyl-CoA and cholesterol it is CoA and cholesterol esters. This reaction is important in order to convert too much cholesterol floating in the cytosol into an insoluble storage form and thus avoid undesired effects from the free cholesterol. In humans, there are two isoforms , the ACAT-1 and ACAT-2 are abbreviated. ACAT-1 is found particularly frequently in macrophages and ACAT-2 in the brush border .
Cholesterol enters the cell through LDL particles , among other things, or is independently synthesized there. LDL is hydrolyzed in the lysosomes and cholesterol, fatty acids and amino acids are released. Cholesterol is built into the cell membrane , processed into hormones or bile acids , or converted back into cholesterol esters by ACAT and thus stored in a storage form. Buildings of cholesterol esters in macrophages and smooth muscle are the first signs of atherosclerosis .
The enzyme can be inhibited, among other things, by lecimibide .
literature
- Kanome T, Watanabe T, Nishio K, Takahashi K, Hongo S, Miyazaki A: Angiotensin II upregulates acyl-CoA: cholesterol acyltransferase-1 via the angiotensin II Type 1 receptor in human monocyte-macrophages . In: Hypertensive. Res. . 31, No. 9, September 2008, pp. 1801-10. doi : 10.1291 / hypres.31.1801 . PMID 18971559 .
- Iqbal J, Rudel LL, Hussain MM: Microsomal triglyceride transfer protein enhances cellular cholesteryl esterification by relieving product inhibition . In: J. Biol. Chem. . 283, No. 29, July 2008, pp. 19967-80. doi : 10.1074 / jbc.M800398200 . PMID 18502767 .
- Song BL, Wang CH, Yao XM, et al. : Human acyl-CoA: cholesterol acyltransferase 2 gene expression in intestinal Caco-2 cells and in hepatocellular carcinoma . In: Biochem. J. . 394, No. Pt 3, March 2006, pp. 617-26. doi : 10.1042 / BJ20051417 . PMID 16274362 . PMC 1383711 (free full text).
- Individual evidence
- ↑ BRENDA enzyme database: Occurrence in mammals such as Candida albicans
- ↑ KY Kim et al.: Molecular cloning and biochemical characterization of Candida albicans acyl-CoA: sterol acyltransferase, a potential target of antifungal agents. Biochem. Biophys. Res. Commun., 2004, Vol. 319, pp. 911-919 PMID 15184069
- ↑ Juo P.-S .: Concise dictionary of biomedicine and molecular biology , CRC Press, 2001, p. 1008, ISBN 0849309409 , here online
- ↑ UniProt P35610 , UniProt O75908