Abstract
We have identified a novel mitogen- and stress-activated protein kinase (MSK1) that contains two protein kinase domains in a single polypeptide. MSK1 is activated in vitro by MAPK2/ERK2 or SAPK2/p38. Endogenous MSK1 is activated in 293 cells by either growth factor/phorbol ester stimulation, or by exposure to UV radiation, and oxidative and chemical stress. The activation of MSK1 by growth factors/phorbol esters is prevented by PD 98059, which suppresses activation of the MAPK cascade, while the activation of MSK1 by stress stimuli is prevented by SB 203580, a specific inhibitor of SAPK2/p38. In HeLa, PC12 and SK-N-MC cells, PD 98059 and SB 203580 are both required to suppress the activation of MSK1 by TNF, NGF and FGF, respectively, because these agonists activate both the MAPK/ERK and SAPK2/p38 cascades. MSK1 is localized in the nucleus of unstimulated or stimulated cells, and phosphorylates CREB at Ser133 with a Km value far lower than PKA, MAPKAP-K1(p90Rsk) and MAPKAP-K2. The effects of SB 203580, PD 98059 and Ro 318220 on agonist-induced activation of CREB and ATF1 in four cell-lines mirror the effects of these inhibitors on MSK1 activation, and exclude a role for MAPKAP-K1 and MAPKAP-K2/3 in this process. These findings, together with other observations, suggest that MSK1 may mediate the growth-factor and stress-induced activation of CREB.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Activating Transcription Factor 1
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Amino Acid Sequence
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Animals
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Base Sequence
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Calcium-Calmodulin-Dependent Protein Kinases / genetics
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Calcium-Calmodulin-Dependent Protein Kinases / isolation & purification
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Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
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Calcium-Calmodulin-Dependent Protein Kinases / physiology*
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Cell Line
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Cyclic AMP Response Element-Binding Protein / metabolism*
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Cyclic AMP Response Element-Binding Protein / radiation effects
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DNA-Binding Proteins*
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Enzyme Activation / drug effects
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Enzyme Activation / radiation effects
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Epidermal Growth Factor / physiology
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HeLa Cells
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Humans
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Intracellular Signaling Peptides and Proteins
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Kidney
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Mice
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Mitogen-Activated Protein Kinase 1
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Mitogen-Activated Protein Kinases*
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Molecular Sequence Data
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PC12 Cells
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Phosphorylation / radiation effects
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Precipitin Tests
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Protein Serine-Threonine Kinases / genetics
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Protein Serine-Threonine Kinases / isolation & purification
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Protein Serine-Threonine Kinases / metabolism*
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Protein Serine-Threonine Kinases / physiology
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Rats
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Ribosomal Protein S6 Kinases / chemistry
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Ribosomal Protein S6 Kinases / immunology
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Ribosomal Protein S6 Kinases / metabolism
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Ribosomal Protein S6 Kinases, 90-kDa
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Signal Transduction / physiology
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Tetradecanoylphorbol Acetate / pharmacology
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Transcription Factors / metabolism
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Transcription Factors / radiation effects
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Tumor Necrosis Factor-alpha / physiology
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Ultraviolet Rays
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p38 Mitogen-Activated Protein Kinases
Substances
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Activating Transcription Factor 1
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Atf1 protein, mouse
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Cyclic AMP Response Element-Binding Protein
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DNA-Binding Proteins
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Intracellular Signaling Peptides and Proteins
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Transcription Factors
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Tumor Necrosis Factor-alpha
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Epidermal Growth Factor
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MAP-kinase-activated kinase 2
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Protein Serine-Threonine Kinases
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RPS6KA4 protein, human
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Ribosomal Protein S6 Kinases
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Ribosomal Protein S6 Kinases, 90-kDa
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Rps6ka4 protein, mouse
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mitogen and stress-activated protein kinase 1
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Calcium-Calmodulin-Dependent Protein Kinases
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Mitogen-Activated Protein Kinase 1
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Mitogen-Activated Protein Kinases
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p38 Mitogen-Activated Protein Kinases
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Tetradecanoylphorbol Acetate
Associated data
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GENBANK/AF074393
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GENBANK/AF074714
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GENBANK/AF074715