D1 Dopamine Receptor Agonists Mediate Activation of p38 Mitogen-Activated Protein Kinase and c-Jun Amino-Terminal Kinase by a Protein Kinase A-Dependent Mechanism in SK-N-MC Human Neuroblastoma Cells
- Laboratory of Molecular Pharmacology, Department of Pharmacology, MCP-Hahnemann School of Medicine, Allegheny University of the Health Sciences, Philadelphia, Pennsylvania 19129
Abstract
We investigated the effects of D1 dopamine receptor stimulation on the activation of mitogen-activated protein kinases (MAPKs) in SK-N-MC human neuroblastoma cells. We found that the D1 dopamine receptor agonist SKF38393 induced similar time- and dose-related activation of p38 MAPK and c-Jun amino-terminal kinase (JNK), whereas extracellular signal-regulated kinase activity was not affected by D1 dopamine receptor stimulation. Maximal stimulation of p38 MAPK and JNK was observed after a 15-min incubation with 100 μm SKF38393. In contrast, 10 μmquinpirole, a D2 dopamine receptor agonist, did not activate p38 MAPK or JNK. Treatment of cells with 10 μmSCH23390, a D1 dopamine receptor antagonist, significantly inhibited the activation of both kinases by SKF38393. These results indicate that activation of the p38 MAPK and JNK signaling pathways is mediated by dopamine D1 receptors in SK-N-MC neuroblastoma cells. Furthermore, dibutyryl-cAMP mimicked SKF38393-mediated stimulation of p38 MAPK and JNK. Inhibition of protein kinase A by 1 μm H-89 or 10 μm adenosine 3′,5′-cyclic monophosphothioate (Rp-isomer, triethylammonium salt) markedly attenuated the activation of p38 MAPK and JNK. Conversely, the selective protein kinase C inhibitor calphostin C did not block D1 dopamine receptor-stimulated activation of p38 MAPK and JNK. These results demonstrate, for the first time, that the Gs-coupled D1 dopamine receptor activates the p38 MAPK and JNK signaling pathways by a protein kinase A-dependent mechanism.
Footnotes
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Send reprint requests to: Dr. Eitan Friedman, Laboratory of Molecular Pharmacology, Department of Pharmacology, MCP-Hahnemann School of Medicine, Allegheny University of the Health Sciences, 3200 Henry Avenue, Philadelphia, PA 19129. E-mail:friedmane{at}auhs.edu
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This study was supported by United States Public Health Service Grant NS29514 from the National Institute on Aging.
- Abbreviations:
- MAPK
- mitogen-activated protein kinase
- ERK
- extracellular signal-regulated kinase
- JNK
- c-Jun amino-terminal kinase(s)
- PKA
- protein kinase A
- MBP
- myelin basic protein
- PKC
- protein kinase C
- GPCR
- G protein-coupled receptor
- DHX
- dihydrexidine
- MKK
- mitogen-activated protein kinase kinase
- GST
- glutathioneS-transferase
- EGTA
- ethylene glycol bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid
- Rp-cAMPS
- adenosine 3′,5′-cyclic monophosphothioate, Rp-isomer, triethylammonium salt
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- Received May 5, 1998.
- Accepted June 11, 1998.
- The American Society for Pharmacology and Experimental Therapeutics
