A common amino acid polymorphism in insulin receptor substrate-1 causes impaired insulin signaling. Evidence from transfection studies

J Clin Invest. 1996 Jun 1;97(11):2569-75. doi: 10.1172/JCI118705.


Insulin receptor substrates-1 (IRS-1) is the major cytoplasmic substrate of the insulin and IGF-1 receptors. Recent studies have identified multiple sequence variants of IRS-1, especially in patients with non-insulin-dependent diabetes mellitus. In the present study, we have examined insulin-stimulated processes in 32D(IR) cells, a myeloid progenitor cell stably overexpressing the insulin receptor, transfected with wild-type human-IRS-1 or the most common human variant of IRS-1 in which glycine 972 is replaced by arginine. As compared to wild-type IRS-1, insulin stimulation of cells transfected with mutant IRS-1 exhibited a 32% decrease in incorporation of [3H]thymidine into DNA (P = 0.002), a 36% decrease in IRS-1 associated phosphatidylinositol (PI) 3-kinase activity (P = 0.004) and a 25% decrease in binding of the p85 regulatory subunit of PI 3-kinase to IRS-1 (P = 0.002). There was also a tendency for a decrease in Grb2 binding to IRS-1 and insulin-stimulated mitogen-activated protein kinase activity, however, these were not statistically significant. The changes occurred with no change in insulin receptor or IRS-1 tyrosine phosphorylation. These data indicate that the mutation in codon 972 in IRS-1 impairs insulin-stimulated signaling, especially along the PI 3-kinase pathway, and may contribute to insulin resistance in normal and diabetic populations.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Arginine
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
  • Cell Line
  • DNA / biosynthesis
  • Diabetes Mellitus, Type 2 / genetics
  • Enzyme Activation
  • Gene Expression
  • Glycine
  • Hematopoietic Stem Cells
  • Humans
  • Insulin / pharmacology*
  • Insulin Receptor Substrate Proteins
  • Mutagenesis, Site-Directed
  • Phosphatidylinositol 3-Kinases
  • Phosphoproteins / genetics*
  • Phosphoproteins / metabolism*
  • Phosphorylation
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism
  • Polymerase Chain Reaction
  • Polymorphism, Genetic*
  • Receptor, Insulin / biosynthesis
  • Receptor, Insulin / physiology*
  • Recombinant Proteins / metabolism
  • Signal Transduction*
  • Thymidine / metabolism
  • Transfection


  • IRS1 protein, human
  • Insulin
  • Insulin Receptor Substrate Proteins
  • Phosphoproteins
  • Recombinant Proteins
  • DNA
  • Arginine
  • Phosphatidylinositol 3-Kinases
  • Phosphotransferases (Alcohol Group Acceptor)
  • Receptor, Insulin
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Glycine
  • Thymidine