Inactivation of JNK activity by mitogen-activated protein kinase phosphatase-2 in EAhy926 endothelial cells is dependent upon agonist-specific JNK translocation to the nucleus.
We have investigated the termination of agonist-stimulated mitogen-activated protein (MAP) kinase activity in EAhy926 cells by MAP kinase phosphatase-2 (MKP-2). In cells expressing either wild-type (WT) or catalytically inactive (CI)-MKP-2, there was no significant differences in TNFalpha-stimulated JNK or p38 MAP kinase activity, however hydrogen peroxide (H2O2)-stimulated JNK activity was substantially reduced in WT-MKP-2 expressing clones and enhanced in cells expressing CI-MKP-2. Consistent with these findings, we observed substantial nuclear translocation of JNK occurred in response to H2O2 but not TNFalpha. Using a phosphospecific anti-JNK antibody, we found that TNFalpha-stimulated JNK activity was associated principally with the cytosol while in response to H2O2, JNK activity was found within the nucleus. These results show that the role of MKP-2 in terminating JNK activity is determined by the translocation of JNK to the nucleus, which is under agonist-specific regulation and not a universal cellular response to stimulation.
Department of Physiology and Pharmacology, Strathclyde Institute for Biosciences, Strathclyde University, 27 Taylor Street, G4 ONR, Scotland, Glasgow, UK.
C J
CJ
Robinson
C M
CM
Sloss
R
R
Plevin
D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D002467:Cell Nucleus / Q000201:enzymology*; D054637:Dual-Specificity Phosphatases; D004727:Endothelium / Q000166:cytology* / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000819:agonists / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases; D054639:Mitogen-Activated Protein Kinase Phosphatases; D020928:Mitogen-Activated Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D054648:Protein Phosphatase 2; D021381:Protein Transport / Q000502:physiology; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D013379:Substrate Specificity; D014409:Tumor Necrosis Factor-alpha / Q000819:agonists / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases
C405618:105AD7 antibody; D000888:Antibodies, Anti-Idiotypic; D014409:Tumor Necrosis Factor-alpha; D006861:Hydrogen Peroxide; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D054639:Mitogen-Activated Protein Kinase Phosphatases; D054648:Protein Phosphatase 2; C490583:DUSP4 protein, human; D054637:Dual-Specificity Phosphatases; D017027:Protein Tyrosine Phosphatases