Regulation of the biosynthesis of acyl analogs of platelet-activating factor by purinergic agonist in endothelial cells

We have previously shown that platelet-activating factor (PAF)-dependent transacetylase: (TA) contains three catalytic activities, namely PAF: lysophospholipid TA (TA(L)), PAF: sphingosine TA (TA(S)) and PAF acetylhydrolase, It serves as a modifier of PAP actions by producing different lipid signal molecules. The TA(L) activity is involved in the biosynthesis of acyl analogs of PAF (acyl-PAF, 1-acyl-2-acetyl-sn-glycero-3-phosphocholine, acylacetyl-GPC) in agonist-stimulated endothelial cells. In the present investigation, we have studied the mechanism(s) by which the TA activity is regulated in ATP-treated endothelial cells. We have demonstrated that ATP, and thiol-modifying agents with ATP, specifically regulate only the TA(L) part of the TA activities, (C) 2000 Federation of European Biochemical Societies, Published by Elsevier Science B.V. All rights reserved.