Ough threeWe gratefully acknowledge the support of National Institutes of Health
Ough threeWe gratefully acknowledge the assistance of National Institutes of TL1A/TNFSF15 Protein Species Overall health Grants R01 DK068437, R01 DK079221, and R21 AA021336 which permitted this function to be undertaken. Manuscript received 6 September 2013 and in IL-12 Protein Gene ID revised type 22 October 2013. Published, JLR Papers in Press, November 1, 2013 DOI 10.1194jlr.MAbbreviations: ARAT, acyl-CoA:retinol acyltransferase; CRABP(I or II), cellular-retinoic acid-binding protein (type I or II); CRBP(I, II, or III), cellular retinol-binding protein (kind I, II, or III); CrbpI , cellular retinol-binding protein, kind I-deficient; CYP26A1, cytochrome 26A1; CYP26B1, cytochrome 26B1; DGAT1, diacylglycerol acyltransferase 1; Dgat1 , diacylglycerol acyltransferase 1-deficient; LRAT, lecithin:retinol acyltransferase; Lrat , lecithin:retinol acyltransferasedeficient; qPCR, quantitative polymerase chain reaction; RA, retinoic acid; RAR, retinoic acid receptor; Rar two, retinoic acid receptor- isoform 2; RBP4, retinol-binding protein; Rbp4 , retinol-binding protein-deficient; RE, retinyl ester. 1 To whom correspondence really should be addressed. e-mail: wsb2columbia.edu two Retinol-binding protein is abbreviated in the literature either as RBP or making use of its gene nomenclature, RBP4. All through the post, we’ll employ solely RBP4 but the reader must be conscious that RBP and RBP4 signify the identical protein.Copyright 2014 by the American Society for Biochemistry and Molecular Biology, Inc.Journal of Lipid Study Volume 55,This short article is accessible online at http:jlr.organd other tissues are in a position to catalyze RE formation; one requires an acyl-CoA-dependent mechanism and also the other an acyl-CoA-independent method (115). The acyl-Co-Adependent mechanism is attributed to an acyl-CoA:retinol acyltransferase (ARAT) activity (92). The acyl-CoA-independent synthesis of REs was shown early on to involve the transesterification of a fatty acyl group in the sn-1 position of a membrane phosphatidylcholine to retinol, as well as the enzyme accountable for this transesterification was termed lecithin:retinol acyltransferase (LRAT) (135). Studies of Lrat-deficient (Lrat ) mice have established that LRAT is responsible for most, but not all, REs synthesized within the physique (168). Incredibly few REs can be detected within the liver, eyes, or lungs of Lrat mice fed a manage chow diet plan (17). The sole tissue where substantial REs accumulate in Lrat mice is adipose tissue, exactly where concentrations of REs are elevated by 2- to 3-fold more than these measured in matched wild-type (WT) mice (17, 18). A number of groups have reported in vitro studies demonstrating that recombinant diacylglycerol acyltransferase 1 (DGAT1), an enzyme that catalyzes the formation of triglyceride from diglycerides and fatty acyl-CoAs (191), also catalyzes the acyl-CoA-dependent esterification of retinol (17, 22, 23). Thus, DGAT1 possesses ARAT activity. Subsequently, through investigations of Dgat1-deficient (Dgat1 ), Lrat , and Lrat Dgat1 mice, we established that DGAT1 can act as a physiologically essential ARAT in mouse intestine (24). Shih et al. (25), through study of Dgat1 mice, demonstrated that DGAT1 acts physiologically in catalyzing RE synthesis in mouse skin. Dgat1 is highly expressed in the liver, exactly where it has been shown to have a role in hepatic triglyceride synthesis (19, 20, 26). Dgat1 is also highly expressed in adipose tissue (26). The literature suggests that ARAT activities might become active only in occasions of excessive retinol availability (279). The literature.
