MNK1, a new MAP kinase-activated protein kinase, isolated by a novel expression screening method for identifying protein kinase substrates

EMBO J. 1997 Apr 15;16(8):1921-33. doi: 10.1093/emboj/16.8.1921.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Calcium-Calmodulin-Dependent Protein Kinases / antagonists & inhibitors
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
  • Cell Line
  • Cloning, Molecular / methods*
  • DNA, Complementary / genetics
  • Enzyme Activation
  • Enzyme Inhibitors / pharmacology
  • Flavonoids / pharmacology
  • HeLa Cells
  • Humans
  • Imidazoles / pharmacology
  • Intracellular Signaling Peptides and Proteins
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases*
  • Molecular Sequence Data
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Pyridines / pharmacology
  • Recombinant Fusion Proteins
  • Sequence Homology, Amino Acid
  • Signal Transduction / physiology
  • Spodoptera
  • Substrate Specificity
  • p38 Mitogen-Activated Protein Kinases

Substances

  • DNA, Complementary
  • Enzyme Inhibitors
  • Flavonoids
  • Imidazoles
  • Intracellular Signaling Peptides and Proteins
  • Pyridines
  • Recombinant Fusion Proteins
  • MKNK1 protein, human
  • Protein-Serine-Threonine Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • 4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one

Associated data

  • GENBANK/AB000409
  • GENBANK/AB014641