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Constitutive activation of mitogen-activated protein kinase-activated protein kinase 2 by mutation of phosphorylation sites and an A-helix motif

Item Type:Article
Title:Constitutive activation of mitogen-activated protein kinase-activated protein kinase 2 by mutation of phosphorylation sites and an A-helix motif
Creators Name:Engel, K. and Schultz, H. and Martin, F. and Kotlyarov, A. and Plath, K. and Hahn, M. and Heinemann, U. and Gaestel, M.
Abstract:A recently described downstream target of mitogen-activated protein kinases (MAPKs) is the MAPK-activated protein (MAPKAP) kinase 2 which has been shown to be responsible for small heat shock protein phosphorylation. We have analyzed the mechanism of MAPKAP kinase 2 activation by MAPK phosphorylation using a recombinant MAPKAP kinase 2-fusion protein, p44MAPK and p38/40MAPK in vitro and using an epitope-tagged MAPKAP kinase 2 in heat-shocked NIH 3T3 cells. It is demonstrated that, in addition to the known phosphorylation of the threonine residue carboxyl-terminal to the catalytic domain, Thr-317, activation of MAPKAP kinase 2 in vitro and in vivo is dependent on phosphorylation of a second threonine residue, Thr-205, which is located within the catalytic domain and which is highly conserved in several protein kinases. Constitutive activation of MAPKAP kinase 2 is obtained by replacement of both of these threonine residues by glutamic acid. A constitutively active form of MAPKAP kinase 2 is also obtained by deletion of a carboxyl-terminal region containing Thr-317 and the A-helix motif or by replacing the conserved residues of the A-helix. These data suggest a dual mechanism of MAPKAP kinase 2 activation by phosphorylation of Thr-205 inside the catalytic domain and by phosphorylation of Thr-317 outside the catalytic domain involving an autoinhibitory A-helix motif.
Keywords:3T3 Cells, Amino Acid Sequence, Base Sequence, Binding Sites, Calcium-Calmodulin-Dependent Protein Kinases, Cultured Tumor Cells, DNA Primers, Enzyme Activation, Hot Temperature, Intracellular Signaling Peptides and Proteins, Mitogen-Activated Protein Kinase 3, Mitogen-Activated Protein Kinases, Molecular Models, Molecular Sequence Data, Mutation, Phosphorylation, Protein-Serine-Threonine Kinases, Recombinant Fusion Proteins, Secondary Protein Structure, Sequence Deletion, Site-Directed Mutagenesis, Animals, Mice
Source:Journal of Biological Chemistry
ISSN:0021-9258
Publisher:American Society for Biochemistry and Molecular Biology (U.S.A.)
Volume:270
Number:45
Page Range:27213-27221
Date:10 November 1995
Official Publication:https://doi.org/10.1074/jbc.270.45.27213
PubMed:View item in PubMed

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