Activation of myocardial cAMP-dependent protein kinase by lysoplasmenylcholine.
Plasmalogen-specific, calcium-independent phospholipase A2 (iPLA2) is activated during myocardial ischemia. Accordingly, we have assessed the activation of myocardial protein kinases by the iPLA2 product, lysoplasmenylcholine. Lysoplasmenylcholine-activated protein kinase activity from heart cytosol fractionated on a DE-52 column was identified as cAMP-dependent protein kinase (PKA) based on the following: (1) protein kinase activity stimulated by cAMP and lysoplasmenylcholine co-eluted on sequential chromatographic steps; (2) lysoplasmenylcholine-activated protein kinase activity was inhibited by the PKA inhibitor, PKI; and (3) the unprimed PKA form generated from the primed form of PKA was activated by cAMP and lysoplasmenylcholine. These results demonstrate a novel mechanism for PKA activation by lysoplasmenylcholine.
Williams
S D
SD
Department of Biochemistry and Molecular Biology, St. Louis University Health Science Center, MO 63104, USA.
Ford
D A
DA
D000818:Animals; D002352:Carrier Proteins / Q000494:pharmacology; D002417:Cattle; D002852:Chromatography, Ion Exchange / Q000379:methods; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D008246:Lysophospholipids / Q000494:pharmacology*; D009206:Myocardium / Q000737:chemistry / Q000201:enzymology*; D009842:Oligopeptides / Q000378:metabolism; D010750:Phosphoproteins / Q000032:analysis; D010766:Phosphorylation; D011817:Rabbits
D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D008246:Lysophospholipids; D009842:Oligopeptides; D010750:Phosphoproteins; C021215:lysoplasmalogens; C015482:protein kinase modulator; C037642:kemptide; D017868:Cyclic AMP-Dependent Protein Kinases