Reciprocal allosteric regulation of p38γ and PTPN3 involves a PDZ domain-modulated complex formation

Sci Signal. 2014 Oct 14;7(347):ra98. doi: 10.1126/scisignal.2005722.

Abstract

The mitogen-activated protein kinase p38γ (also known as MAPK12) and its specific phosphatase PTPN3 (also known as PTPH1) cooperate to promote Ras-induced oncogenesis. We determined the architecture of the PTPN3-p38γ complex by a hybrid method combining x-ray crystallography, small-angle x-ray scattering, and chemical cross-linking coupled to mass spectrometry. A unique feature of the glutamic acid-containing loop (E-loop) of the phosphatase domain defined the substrate specificity of PTPN3 toward fully activated p38γ. The solution structure revealed the formation of an active-state complex between p38γ and the phosphatase domain of PTPN3. The PDZ domain of PTPN3 stabilized the active-state complex through an interaction with the PDZ-binding motif of p38γ. This interaction alleviated autoinhibition of PTPN3, enabling efficient tyrosine dephosphorylation of p38γ. Our findings may enable structure-based drug design targeting the PTPN3-p38γ interaction as an anticancer therapeutic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allosteric Regulation
  • Antineoplastic Agents / chemistry
  • Cloning, Molecular
  • Cross-Linking Reagents / chemistry
  • Crystallography, X-Ray
  • Drug Design
  • Glutathione Transferase / metabolism
  • Humans
  • Mass Spectrometry
  • Mitogen-Activated Protein Kinase 12 / chemistry*
  • Mutagenesis, Site-Directed
  • Neopterin / chemistry
  • PDZ Domains*
  • Peptides / chemistry
  • Phosphorylation
  • Protein Binding
  • Protein Tyrosine Phosphatase, Non-Receptor Type 3 / chemistry*
  • Spectrometry, Mass, Electrospray Ionization
  • Substrate Specificity
  • Trypsin / chemistry
  • Tyrosine / chemistry
  • Ultracentrifugation

Substances

  • Antineoplastic Agents
  • Cross-Linking Reagents
  • Peptides
  • Tyrosine
  • Neopterin
  • Glutathione Transferase
  • Mitogen-Activated Protein Kinase 12
  • PTPN3 protein, human
  • Protein Tyrosine Phosphatase, Non-Receptor Type 3
  • Trypsin