A novel redox-based switch: LMW-PTP oxidation enhances Grb2 binding and leads to ERK activation

Biochem Biophys Res Commun. 2006 Sep 22;348(2):367-73. doi: 10.1016/j.bbrc.2006.07.091. Epub 2006 Jul 28.

Abstract

Low molecular weight-PTP has been reported as a redox-sensitive protein during both platelet-derived growth factor and integrin signalling. In response to oxidation the phosphatase undergoes a reversible inactivation, which in turn leads to the increase in tyrosine phosphorylation of its substrates and the properly executed anchorage-dependent proliferation program. Here, we report that an exogenous oxidative stress enhances LMW-PTP tyrosine phosphorylation, through oxidation/inactivation of the enzyme, thus preventing its auto-dephosphorylation activity. In particular, we observed a selective hyper-phosphorylation of Tyr132, that acts as a docking site for the adaptor protein Grb2. The redox-dependent enhancement of Grb2 recruitment to LMW-PTP ultimately leads to an improvement of ERK activation, likely triggering a prosurvival signal against the oxidant environment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Line, Tumor
  • Enzyme Activation
  • Extracellular Signal-Regulated MAP Kinases / metabolism*
  • GRB2 Adaptor Protein / metabolism*
  • Humans
  • Isoenzymes / metabolism
  • Mice
  • NIH 3T3 Cells / radiation effects
  • Oxidation-Reduction
  • Platelet-Derived Growth Factor / pharmacology
  • Protein Tyrosine Phosphatases / metabolism*
  • Proto-Oncogene Proteins / metabolism
  • Reactive Oxygen Species / pharmacology
  • Tyrosine / metabolism
  • Ultraviolet Rays

Substances

  • GRB2 Adaptor Protein
  • Isoenzymes
  • Platelet-Derived Growth Factor
  • Proto-Oncogene Proteins
  • Reactive Oxygen Species
  • Tyrosine
  • Extracellular Signal-Regulated MAP Kinases
  • Acp1 protein, mouse
  • Protein Tyrosine Phosphatases