Anisomycin-activated protein kinases p45 and p55 but not mitogen-activated protein kinases ERK-1 and -2 are implicated in the induction of c-fos and c-jun.
Independent of its ability to block translation, anisomycin intrinsically initiates intracellular signals and immediate-early gene induction [L. C. Mahadevan and D. R. Edwards, Nature (London) 349:747-749, 1991]. Here, we characterize further its action as a potent, selective signalling agonist. In-gel kinase assays show that epidermal growth factor (EGF) transiently activates five kinases: the mitogen-activated protein (MAP) kinases ERK-1 and -2, and three others, p45, p55, and p80. Anisomycin, at inhibitory and subinhibitory concentrations, does not activate ERK-1 and -2 but elicits strong sustained activation of p45 and p55, which are unique in being serine kinases whose detection is enhanced with poly-Glu/Tyr or poly-Glu/Phe copolymerized in these gels. Translational arrest using emetine or puromycin does not activate p45 and p55 but does prolong EGF-stimulated ERK-1 and -2 activation. Rapamycin, which blocks anisomycin-stimulated p70/85S6k activation without affecting nuclear responses, has no effect on p45 or p55 kinase. p45 and p55 are activable by okadaic acid or UV irradiation, and both kinases phosphorylate the c-Jun NH2-terminal peptide 1-79, putatively placing them within c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK) subfamily of MAP kinases. Thus, the EGF- and anisomycin-activated kinases p45 and p55 are strongly implicated in signalling to c-fos and c-jun, whereas the MAP kinases ERK-1 and -2 are not essential for this process.
Cano
E
E
Nuclear Signalling Laboratory, Randall Institute, King's College London, United Kingdom.
Hazzalin
C A
CA
Mahadevan
L C
LC
D000818:Animals; D000841:Anisomycin / Q000494:pharmacology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects / Q000528:radiation effects; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004988:Ethers, Cyclic / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D016762:Genes, fos / Q000187:drug effects; D016758:Genes, jun / Q000187:drug effects; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D008934:Mitogens / Q000494:pharmacology; D019319:Okadaic Acid; D011090:Polyenes / Q000494:pharmacology; D014176:Protein Biosynthesis / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D020123:Sirolimus; D013379:Substrate Specificity; D015533:Transcriptional Activation
D004988:Ethers, Cyclic; D008934:Mitogens; D011090:Polyenes; D016755:Proto-Oncogene Proteins c-jun; D019319:Okadaic Acid; D004815:Epidermal Growth Factor; D000841:Anisomycin; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D020123:Sirolimus