Nitric Oxide Activation of p38 Mitogen-activated Protein Kinase in 293T Fibroblasts Requires cGMP-dependent Protein Kinase*
- From the Department of Pharmacology, MC868, University of Illinois at Chicago, Chicago, Illinois 60612
Abstract
An increase in cellular levels of cyclic nucleotides activates serine/threonine-dependent kinases that lead to diverse physiological effects. Recently we reported the activation of the p38 mitogen-activated protein kinase (MAPK) pathway in neutrophils by a cGMP-dependent mechanism. In this study we demonstrated that exogenously supplied nitric oxide leads to activation of p38 MAPK in 293T fibroblasts. Phosphorylation of p38 corresponded with an increase in ATF-2-dependent gene expression. The effect of nitric oxide was mimicked by addition of 8-bromo-cGMP, indicating that activation of soluble guanylyl cyclase was involved. The importance of cGMP-dependent protein kinase in the activation of p38 MAPK by nitric oxide in 293T cells was assessed in a transfection based assay. Overexpression of cGMP-dependent protein kinase-1α caused phosphorylation of p38 in these cells and potentiated the effectiveness of cGMP. Overexpression of a catalytically inactive mutant form of this enzyme (T516A) blocked the ability of both nitric oxide and 8-bromo-cGMP to activate p38 as measured by both p38 phosphorylation and ATF-2 driven gene expression. Together, these data demonstrate that nitric oxide stimulates a novel pathway leading to activation of p38 MAPK that requires activation of cGMP-dependent protein kinase.
Footnotes
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↵* This work was supported in part by National Institutes of Health Grants AI33503 and AI40176.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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↵‡ Recipient of a fellowship from the Arthritis Foundation.
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↵§ Established Investigator of the American Heart Association. To whom correspondence should be addressed: Dept. of Pharmacology (MC868), University of Illinois, 835 S. Wolcott Ave., Chicago, IL 60612. Tel.: 312-996-5087; Fax: 312-996-7857.
- Abbreviations:
- PK
-
protein kinase
- MAPK
-
mitogen-activated protein kinase
- ERK
-
extracellular signal-regulated kinase
- JNK
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c-Jun NH2-terminal kinase
- MEK
-
MAPK kinase
- 8-Br-cGMP
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8-bromo cyclic GMP
- VASP
-
vasodilator-stimulated phosphoprotein
- SNP-1
-
sodium nitroprusside
- PCR
-
polymerase chain reaction
- ASK-1
-
apoptosis signal-regulated kinase
- TNF
-
tumor necrosis factor
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- Received June 24, 1999.
- Revision received October 19, 1999.
- The American Society for Biochemistry and Molecular Biology, Inc.
