title: Long-chain acyl-CoA synthetase isoforms differ in preferences for eicosanoid species and long-chain fatty acids.
abstract: Because the signaling eicosanoids, epoxyeicosatrienoic acids (EETs) and HETEs, are esterified to membrane phospholipids, we asked which long-chain acyl-CoA synthetase (ACSL) isoforms would activate these molecules and whether the apparent FA substrate preferences of each ACSL isoform might differ depending on whether it was assayed in mammalian cell membranes or as a purified bacterial recombinant protein. We found that all five ACSL isoforms were able to use EETs and HETEs as substrates and showed by LC-MS/MS that ACSLs produce EET-CoAs. We found differences in substrate preference between ACS assays performed in COS7 cell membranes and recombinant purified proteins. Similarly, preferences and Michaelis-Menten kinetics for long-chain FAs were distinctive. Substrate preferences identified for the purified ACSLs did not correspond to those observed in ACSL-deficient mouse models. Taken together, these data support the concept that each ACSL isoform exhibits a distinct substrate preference, but apparent substrate specificities depend upon multiple factors including membrane character, coactivators, inhibitors, protein interactions, and posttranslational modification.
authors.affiliation: Department of Medicine, Division of Endocrinology, University of North Carolina School of Medicine, Chapel Hill, NC 27599 eklett@med.unc.edu.|Department of Nutrition, University of North Carolina School of Public Health, Chapel Hill, NC 27599.
authors.forename: Eric L
authors.initials: EL
authors.lastname: Klett
authors.affiliation: Department of Medicine, Division of Endocrinology, University of North Carolina School of Medicine, Chapel Hill, NC 27599.|Department of Nutrition, University of North Carolina School of Public Health, Chapel Hill, NC 27599.
authors.forename: Shufen
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Nutrition, University of North Carolina School of Public Health, Chapel Hill, NC 27599.
authors.forename: Alekhya
authors.initials: A
authors.lastname: Yechoor
authors.affiliation: Division of Intramural Research, Epigenetics and Stem Cell Biology Laboratory (ESCBL), National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709.
authors.forename: Fred B
authors.initials: FB
authors.lastname: Lih
authors.affiliation: Department of Nutrition, University of North Carolina School of Public Health, Chapel Hill, NC 27599.
authors.forename: Rosalind A
authors.initials: RA
authors.lastname: Coleman
mesh_terms: D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D003066:Coenzyme A Ligases / Q000378:metabolism*; D015777:Eicosanoids / Q000737:chemistry* / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D051381:Rats; D013379:Substrate Specificity; D000098859:Long-Chain-Fatty-Acid-CoA Ligase
chemical_list: D015777:Eicosanoids; D007527:Isoenzymes; D003066:Coenzyme A Ligases; D000098859:Long-Chain-Fatty-Acid-CoA Ligase
keywords: acyl-coenzyme A; arachidonic acid; cytochrome P450; fatty acid/metabolism; phospholipids