Cellular stresses differentially activate c-Jun N-terminal protein kinases and extracellular signal-regulated protein kinases in cultured ventricular myocytes.
Anisomycin or osmotic stress induced by sorbitol activated c-Jun N-terminal protein kinases (JNKs) in ventricular myocytes cultured from neonatal rat hearts. After 15-30 min, JNK was activated by 10-20-fold. Activation by anisomycin was transient, but that by sorbitol was sustained for at least 4 h. In-gel JNK assays confirmed activation of two renaturable JNKs of 46 and 55 kDa (JNK-46 and JNK-55, respectively). An antibody against human JNK1 immunoprecipitated JNK-46 activity. Endothelin-1, an activator of extracellular signal-regulated protein kinases (ERKs), also transiently activated JNKs by 2-5-fold after 30 min. Phorbol 12-myristate 13-acetate did not activate the JNKs although it activated ERK1 and ERK2, which phosphorylated the c-Jun transactivation domain in vitro. ATP depletion and repletion achieved by incubation in cyanide+deoxyglucose and its subsequent removal from the medium activated the ERKs but failed to activate the JNKs. Sorbitol (but not anisomycin) also stimulated the ERKs. Sorbitol-stimulated JNK activity could be resolved into three peaks by fast protein liquid chromatography on a Mono Q column. The two major peaks contained JNK-46 or JNK-55. These results demonstrate that cellular stresses differentially activate the JNKs and ERKs and that there may be "cross-talk" between these MAPK pathways.
National Heart and Lung Institute, Imperial College of Science, Technology and Medicine, London, United Kingdom.
M A
MA
Bogoyevitch
A J
AJ
Ketterman
P H
PH
Sugden
D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D000841:Anisomycin / Q000494:pharmacology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D002478:Cells, Cultured; D016232:Endothelins / Q000494:pharmacology; D004789:Enzyme Activation; D006352:Heart Ventricles; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D007700:Kinetics; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D008969:Molecular Sequence Data; D009206:Myocardium / Q000201:enzymology*; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology; D011817:Rabbits / Q000276:immunology; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D013012:Sorbitol / Q000494:pharmacology; D013312:Stress, Physiological; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D016232:Endothelins; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D013012:Sorbitol; D000841:Anisomycin; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D013755:Tetradecanoylphorbol Acetate