Nitric oxide activation of p38 mitogen-activated protein kinase in 293T fibroblasts requires cGMP-dependent protein kinase.
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-1alpha 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.
Browning
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DD
Department of Pharmacology, MC868, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
McShane
M P
MP
Marty
C
C
Ye
R D
RD
D015153:Blotting, Western; D002460:Cell Line; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism*; D004789:Enzyme Activation; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009569:Nitric Oxide; D010766:Phosphorylation; D011233:Precipitin Tests; D048051:p38 Mitogen-Activated Protein Kinases
D009569:Nitric Oxide; D017869:Cyclic GMP-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases