MNK1, a new MAP kinase-activated protein kinase, isolated by a novel expression screening method for identifying protein kinase substrates.
We have developed a novel expression screening method for identifying protein kinase substrates. In this method, a lambda phage cDNA expression library is screened by in situ, solid-phase phosphorylation using purified protein kinase and [gamma-32P]ATP. Screening a HeLa cDNA library with ERK1 MAP kinase yielded cDNAs of previously characterized ERK ... substrates, c-Myc and p90RSK, demonstrating the utility of this method for identifying physiological protein kinase substrates. A novel clone isolated in this screen, designated MNK1, encodes a protein-serine/threonine kinase, which is most similar to MAP kinase-activated protein kinase 2 (MAPKAP-K2), 3pK/MAPKAP-K3 and p90RSK. Bacterially expressed MNK1 was phosphorylated and activated in vitro by ERK1 and p38 MAP kinases but not by JNK/SAPK. Further, MNK1 was activated upon stimulation of HeLa cells with 12-O-tetradecanoylphorbol-13-acetate, fetal calf serum, anisomycin, UV irradiation, tumor necrosis factor-alpha, interleukin-1beta, or osmotic shock, and the activation by these stimuli was differentially inhibited by the MEK inhibitor PD098059 or the p38 MAP kinase inhibitor SB202190. Together, these results indicate that MNK1 is a novel class of protein kinase that is activated through both the ERK and p38 MAP kinase signaling pathways.
Mesh Terms:
Amino Acid Sequence, Animals, Base Sequence, Calcium-Calmodulin-Dependent Protein Kinases, Cell Line, Cloning, Molecular, DNA, Complementary, Enzyme Activation, Enzyme Inhibitors, Flavonoids, Hela Cells, Humans, Imidazoles, Intracellular Signaling Peptides and Proteins, Mitogen-Activated Protein Kinase 3, Mitogen-Activated Protein Kinases, Molecular Sequence Data, Phosphorylation, Protein-Serine-Threonine Kinases, Pyridines, Recombinant Fusion Proteins, Sequence Homology, Amino Acid, Signal Transduction, Spodoptera, Substrate Specificity, p38 Mitogen-Activated Protein Kinases
Amino Acid Sequence, Animals, Base Sequence, Calcium-Calmodulin-Dependent Protein Kinases, Cell Line, Cloning, Molecular, DNA, Complementary, Enzyme Activation, Enzyme Inhibitors, Flavonoids, Hela Cells, Humans, Imidazoles, Intracellular Signaling Peptides and Proteins, Mitogen-Activated Protein Kinase 3, Mitogen-Activated Protein Kinases, Molecular Sequence Data, Phosphorylation, Protein-Serine-Threonine Kinases, Pyridines, Recombinant Fusion Proteins, Sequence Homology, Amino Acid, Signal Transduction, Spodoptera, Substrate Specificity, p38 Mitogen-Activated Protein Kinases
EMBO J.
Date: Apr. 15, 1997
PubMed ID: 9155018
View in: Pubmed Google Scholar
Download Curated Data For This Publication
5203
Switch View:
- Interactions 1