Interaction between the p21ras GTPase activating protein and the insulin receptor

J Biol Chem. 1992 Nov 25;267(33):24058-63.

Abstract

We investigated the involvement of the p21ras-GTPase activating protein (GAP) in insulin-induced signal transduction. In cells overexpressing the insulin receptor, we did not observe association between GAP and the insulin receptor after insulin treatment nor the phosphorylation of GAP on tyrosine residues. However, after insulin treatment in the presence of the phosphotyrosine phosphatase inhibitor phenylarsine oxide (PAO), 5-10% of GAP was found to be associated with the insulin receptor, and, in addition, a fraction of total GAP was phosphorylated on tyrosine. Using in vitro binding we showed that the N-terminal part of GAP containing the src-homology domains 2 and 3 (SH2-SH3-SH2 region) is involved in binding to the autophosphorylated insulin receptor beta-chain. In vitro binding between GAP and the autophosphorylated insulin receptor occurred independently of PAO pretreatment. These results suggest that GAP can transiently interact with the insulin receptor after insulin treatment, and this interaction is arrested after PAO pretreatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Animals
  • Arsenicals / pharmacology
  • GTPase-Activating Proteins
  • Humans
  • Immunoblotting
  • Macromolecular Substances
  • Mice
  • Molecular Weight
  • Peptide Mapping
  • Phosphopeptides / isolation & purification
  • Protein Tyrosine Phosphatases / antagonists & inhibitors
  • Protein-Tyrosine Kinases / metabolism*
  • Proteins / isolation & purification
  • Proteins / metabolism*
  • Receptor, Insulin / genetics
  • Receptor, Insulin / isolation & purification
  • Receptor, Insulin / metabolism*
  • Transfection
  • Trypsin

Substances

  • Arsenicals
  • GTPase-Activating Proteins
  • Macromolecular Substances
  • Phosphopeptides
  • Proteins
  • oxophenylarsine
  • Protein-Tyrosine Kinases
  • Receptor, Insulin
  • Protein Tyrosine Phosphatases
  • Trypsin