Abstract
ET-1 stimulated MBP kinase activity in cultured cardiomyocytes. Maximal activation (3.5-fold) was at 5 min. EC50 was 0.2 nM. PMA or PE also increased MBP kinase (4- or 2.5-fold, respectively). Pre-treatment with PMA down-regulated the subsequent response to ET-1 or PMA. ET-1- or PMA-stimulated MBP kinase was resolved into 2 major (peaks II and IV) and 2 minor peaks by FPLC on Mono Q. Peaks II and IV were inactivated by either LAR or PP2A. Renatured MBP kinase activities following SDS-PAGE in MBP-containing gels and immunoblot analysis showed that peak II was a p42 MAP kinase and peak IV was a p44 MAP kinase.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Animals
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Animals, Newborn
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Calcium-Calmodulin-Dependent Protein Kinases
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Cardiomegaly / enzymology
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Cells, Cultured
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Chromatography, Liquid / methods
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Disease Models, Animal
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Endothelins / pharmacology*
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Enzyme Activation
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Glycogen Synthase Kinase 3
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Molecular Sequence Data
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Myocardium / enzymology*
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Phenylephrine / pharmacology*
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Phosphoprotein Phosphatases / metabolism
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Protein Kinases / drug effects*
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Protein Kinases / metabolism
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Rats
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Tetradecanoylphorbol Acetate / pharmacology*
Substances
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Endothelins
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Phenylephrine
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Protein Kinases
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Calcium-Calmodulin-Dependent Protein Kinases
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Glycogen Synthase Kinase 3
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Phosphoprotein Phosphatases
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Tetradecanoylphorbol Acetate