Interaction of mitogen-activated protein kinases with the kinase interaction motif of the tyrosine phosphatase PTP-SL provides substrate specificity and retains ERK2 in the cytoplasm.
ERK1 and ERK2 associate with the tyrosine phosphatase PTP-SL through a kinase interaction motif (KIM) located in the juxtamembrane region of PTP-SL. A glutathione S-transferase (GST)-PTP-SL fusion protein containing the KIM associated with ERK1 and ERK2 as well as with p38/HOG, but not with the related JNK1 kinase or with ... protein kinase A or C. Accordingly, ERK2 showed in vitro substrate specificity to phosphorylate GST-PTP-SL in comparison with GST-c-Jun. Furthermore, tyrosine dephosphorylation of ERK2 by the PTP-SLDeltaKIM mutant was impaired. The in vitro association of ERK1/2 with GST-PTP-SL was highly stable; however, low concentrations of nucleotides partially dissociated the ERK1/2.PTP-SL complex. Partial deletions of the KIM abrogated the association of PTP-SL with ERK1/2, indicating that KIM integrity is required for interaction. Amino acid substitution analysis revealed that Arg and Leu residues within the KIM are essential for the interaction and suggested a regulatory role for Ser(231). Finally, coexpression of PTP-SL and ERK2 in COS-7 cells resulted in the retention of ERK2 in the cytoplasm in a KIM-dependent manner. Our results demonstrate that the noncatalytic region of PTP-SL associates with mitogen-activated protein kinases with high affinity and specificity, providing a mechanism for substrate specificity, and suggest a role for PTP-SL in the regulation of mitogen-activated protein kinase translocation to the nucleus upon activation.
Mesh Terms:
Amino Acid Sequence, Amino Acid Substitution, Animals, Binding Sites, COS Cells, Calcium-Calmodulin-Dependent Protein Kinases, Cattle, Cyclic AMP-Dependent Protein Kinases, Cytoplasm, Intracellular Signaling Peptides and Proteins, Isoenzymes, JNK Mitogen-Activated Protein Kinases, Kinetics, Mitogen-Activated Protein Kinase 1, Mitogen-Activated Protein Kinase 3, Mitogen-Activated Protein Kinases, Mutagenesis, Site-Directed, Nerve Tissue Proteins, Protein Kinase C, Protein Kinase C-alpha, Protein Tyrosine Phosphatases, Recombinant Fusion Proteins, Sequence Deletion, Serine, Substrate Specificity, Transfection
Amino Acid Sequence, Amino Acid Substitution, Animals, Binding Sites, COS Cells, Calcium-Calmodulin-Dependent Protein Kinases, Cattle, Cyclic AMP-Dependent Protein Kinases, Cytoplasm, Intracellular Signaling Peptides and Proteins, Isoenzymes, JNK Mitogen-Activated Protein Kinases, Kinetics, Mitogen-Activated Protein Kinase 1, Mitogen-Activated Protein Kinase 3, Mitogen-Activated Protein Kinases, Mutagenesis, Site-Directed, Nerve Tissue Proteins, Protein Kinase C, Protein Kinase C-alpha, Protein Tyrosine Phosphatases, Recombinant Fusion Proteins, Sequence Deletion, Serine, Substrate Specificity, Transfection
J. Biol. Chem.
Date: Jul. 30, 1999
PubMed ID: 10419510
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