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PubMed · 2622457

Interactions between cyclic AMP-dependent protein phosphorylation and lipid transmethylation reactions in isolated porcine cardiac sarcolemma.

R Vetter·J Dai·V Panagia·N S Dhalla
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Abstract

Premethylation of purified porcine cardiac sarcolemma (SL) in the presence of 0.15, 10 and 150 microM S-adenosyl-L-methionine (AdoMet) did not change the phosphorylation of SL proteins catalyzed either by intrinsic cyclic AMP-dependent protein kinase (cAK) or by added catalytic (C) subunit of this enzyme. On the other hand, membrane exhibited increased lipid methyltransferase activity after preincubation with MgATP and C subunit. Prephosphorylation of membranes stimulated the total [3H]-methyl incorporation into SL lipids assayed at 0.15 microM [3H]AdoMet due to an enhancement of Vmax and without changes in the Km value for AdoMet. Analysis of the methylated lipid products revealed an increased methyl group incorporation into a nonpolar lipid fraction whereas phosphatidylethanolamine-N-methylation was not affected by phosphorylation. The results suggest that the cyclic AMP-mediated signal transduction at the level of cardiac SL is not affected by methylation-induced modifications of the membrane lipid microdomains. On the other hand, an intrinsic SL lipid methyltransferase activity is apparently not related to the N-methylation of phospholipids, is modulated by cyclic AMP-dependent protein phosphorylation.

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Adenosine TriphosphateAnimalsCell MembraneKineticsLipid MetabolismMethylationMethyltransferasesMyocardiumProtein KinasesS-AdenosylmethionineSarcolemmaSwineJournal ArticleResearch Support, Non-U.S. Gov't

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R Vetter, J Dai, V Panagia, N S Dhalla. Interactions between cyclic AMP-dependent protein phosphorylation and lipid transmethylation reactions in isolated porcine cardiac sarcolemma.. https://doi.org/10.1007/bf00228079

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