Evidence for the importance of OxPAPC interaction with cysteines in regulating endothelial cell function
Ontology highlight
ABSTRACT: Oxidation products of 1-palmitoyl-2-arachidonoyl-sn-glycerol-2-phosphatidylcholine (PAPC), referred to as OxPAPC, accumulate in atherosclerotic lesions and regulate over 1000 genes in human aortic endothelial cells (HAEC). We previously demonstrated that OxPAPC covalently binds to a number of proteins in HAEC. The goal of these studies was to gain insight into the binding mechanism and determine if binding regulates activity. In whole cells N-acetylcysteine inhibited gene regulation by OxPAPC, and blocking cell cysteines with N-ethylmaleimide strongly inhibited OxPAPC binding. Using MS, we demonstrate that most of the binding of OxPAPC to cysteine is mediated by PEIPC. We also show that OxPAPC binds to a model protein, H-Ras, at cysteines previously shown to regulate activity in response to 15dPGJ2. This binding was observed with recombinant protein and in cells overexpressing H-Ras. 15dPGJ2 and OxPAPC increased H-Ras activity at comparable concentrations. Using microarray analysis, we demonstrate a considerable overlap of gene regulation by OxPAPC and 15dPGJ2 in HAEC, suggesting that some effects attributed to 15dPGJ2 may also be regulated by OxPAPC since OxPAPC lipids and 15dPGJ2 both accumulate in inflammatory sites. Overall, we provide evidence for the importance of OxPAPC-cysteine interactions in regulating HAEC function.
ORGANISM(S): Homo sapiens
PROVIDER: GSE35709 | GEO | 2012/02/14
SECONDARY ACCESSION(S): PRJNA152049
REPOSITORIES: GEO
ACCESS DATA