Abstract
Protein kinase D (PKD) is a serine-threonine protein kinase with distinct structural features and enzymological properties. Herein we demonstrate that lysophosphatidic acid (LPA) induces rapid PKD activation in mouse Swiss 3T3 and Rat-1 cells. LPA induced PKD activation in a concentration-dependent fashion with maximal stimulation (7.6-fold) achieved at 5 microM. Treatment of Swiss 3T3 cells with the protein kinase C (PKC) inhibitors GF-I, Ro-31-8220, and Gö-7874 completely abrogated PKD activation induced by LPA at concentrations that did not inhibit PKD activity when added directly to the in vitro kinase assays. PKD activation induced by LPA was attenuated markedly and selectively by prior exposure of either Swiss 3T3 or Rat-1 cells to pertussis toxin (PTx) in a concentration-dependent manner. In contrast, treatment with the protein tyrosine kinase inhibitor genistein, the MEK inhibitor PD-098059, or the phosphoinositide 3-kinase inhibitor wortmannin did not affect PKD activation in response to LPA. These results provide the first example of PTx-sensitive and PKC-dependent PKD activation and identify a novel G(i)-dependent event in the action of LPA.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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3T3 Cells / enzymology
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Animals
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Enzyme Activation / drug effects
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Enzyme Inhibitors / pharmacology
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Estrenes / pharmacology
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GTP-Binding Proteins / metabolism*
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Indoles / pharmacology
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Lysophospholipids / pharmacology*
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MAP Kinase Signaling System / drug effects*
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MAP Kinase Signaling System / physiology
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Maleimides / pharmacology
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Mice
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Mitogen-Activated Protein Kinase 1 / metabolism
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Mitogen-Activated Protein Kinase 3
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Mitogen-Activated Protein Kinases / metabolism
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Pertussis Toxin*
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Phosphodiesterase Inhibitors / pharmacology
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Phosphorylation
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Protein Kinase C / antagonists & inhibitors
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Protein Kinase C / metabolism*
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Pyrrolidinones / pharmacology
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Rats
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Virulence Factors, Bordetella / pharmacology*
Substances
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Enzyme Inhibitors
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Estrenes
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Indoles
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Lysophospholipids
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Maleimides
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Phosphodiesterase Inhibitors
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Pyrrolidinones
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Virulence Factors, Bordetella
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1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione
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Pertussis Toxin
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protein kinase D
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Protein Kinase C
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Mitogen-Activated Protein Kinase 1
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Mitogen-Activated Protein Kinase 3
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Mitogen-Activated Protein Kinases
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GTP-Binding Proteins
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bisindolylmaleimide I
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Ro 31-8220