| Autor: |
Meij, Johanna, Paolillo, Giovanni, Bezstarosti, Karel, Verdouw, Pieter, Panagia, Vincenzo, Lamers, Jos |
| Zdroj: |
Molecular & Cellular Biochemistry; Nov1989, Vol. 90 Issue 2, p137-144, 8p |
| Abstrakt: |
Both phosphatidylethanolamine(PE)-N-methylation and phosphatidyl-inositol bisphosphate(PI-bisphosphate) breakdown potentially modify the microdomains in the sarcolemmal lipid bilayer. In this study the possibility of a mutual interaction between the enzymes responsible for these phospholipid reactions is examined. In sarcolemma purified from rat heart, prior hydrolysis of PI lipids by exogenous specific phospholipase C inhibited (to 75, 59 and 78% of control for sites 1, 11 and 11, respectively) the PE-N-methyltransferase system. In cultured rat cardiomyocytes the addition of L-methionine, a precursor for the methyl donor S-adenosylmethionine, stimulated PE-N-methylation in a concentration (0.2-300 µM)-dependent manner. Methionine (50 µM) decreased the basal rate of PI-bisphosphate hydrolysis (to 72% of control), but had no effect on the phenylephrine-stimulated PI-bisphosphate hydrolysis. Maximal activation of the PI-bisphosphate breakdown by 30 µM phenylephrine did not affect the rate of PE-N-methylation in the presence of exogenous methionine (50 µM). These findings support the existence of interactions, although discrete, between the enzymes involved in the PE-N-methylation and PI turnover. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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