Abstract
IRS-1 is an insulin receptor substrate that undergoes tyrosine phosphorylation and associates with the phosphatidylinositol (PtdIns) 3′-kinase immediately after insulin stimulation. Recombinant IRS-1 protein was tyrosine phosphorylated by the insulin receptor in vitro and associated with the PtdIns 3′-kinase from lysates of quiescent 3T3 fibroblasts. Bacterial fusion proteins containing the src homology 2 domains (SH2 domains) of the 85-kDa subunit (p85) of the PtdIns 3′-kinase bound quantitatively to tyrosine phosphorylated, but not unphosphorylated, IRS-1, and this association was blocked by phosphotyrosine-containing synthetic peptides. Moreover, the phosphorylated peptides and the SH2 domains each inhibited binding of PtdIns 3′-kinase to IRS-1. Phosphorylated IRS-1 activated PtdIns 3′-kinase in anti-p85 immunoprecipitates in vitro, and this activation was blocked by SH2 domain fusion proteins. These data suggest that the interaction between PtdIns 3′-kinase and IRS-1 is mediated by tyrosine phosphorylated motifs on IRS-1 and the SH2 domains of p85, and IRS-1 activates PtdIns 3′-kinase by binding to the SH2 domains of p85. Thus, IRS-1 likely serves to transmit the insulin signal by binding and regulating intracellular enzymes containing SH2 domains.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 10350-10354 |
| Number of pages | 5 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 89 |
| Issue number | 21 |
| State | Published - 1992 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Genetics
- General
Cite this
IRS-1 activates phosphatidylinositol 3′-kinase by associating with src homology 2 domains of p85. / Myers, Martin G.; Backer, Jonathan M.; Sun, Xiao Jian; Shoelson, Steven; Hu, Patrick; Schlessinger, Joseph; Yoakim, Monique; Schaffhausen, Brian; White, Morris F.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 89, No. 21, 1992, p. 10350-10354.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - IRS-1 activates phosphatidylinositol 3′-kinase by associating with src homology 2 domains of p85
AU - Myers, Martin G.
AU - Backer, Jonathan M.
AU - Sun, Xiao Jian
AU - Shoelson, Steven
AU - Hu, Patrick
AU - Schlessinger, Joseph
AU - Yoakim, Monique
AU - Schaffhausen, Brian
AU - White, Morris F.
PY - 1992
Y1 - 1992
N2 - IRS-1 is an insulin receptor substrate that undergoes tyrosine phosphorylation and associates with the phosphatidylinositol (PtdIns) 3′-kinase immediately after insulin stimulation. Recombinant IRS-1 protein was tyrosine phosphorylated by the insulin receptor in vitro and associated with the PtdIns 3′-kinase from lysates of quiescent 3T3 fibroblasts. Bacterial fusion proteins containing the src homology 2 domains (SH2 domains) of the 85-kDa subunit (p85) of the PtdIns 3′-kinase bound quantitatively to tyrosine phosphorylated, but not unphosphorylated, IRS-1, and this association was blocked by phosphotyrosine-containing synthetic peptides. Moreover, the phosphorylated peptides and the SH2 domains each inhibited binding of PtdIns 3′-kinase to IRS-1. Phosphorylated IRS-1 activated PtdIns 3′-kinase in anti-p85 immunoprecipitates in vitro, and this activation was blocked by SH2 domain fusion proteins. These data suggest that the interaction between PtdIns 3′-kinase and IRS-1 is mediated by tyrosine phosphorylated motifs on IRS-1 and the SH2 domains of p85, and IRS-1 activates PtdIns 3′-kinase by binding to the SH2 domains of p85. Thus, IRS-1 likely serves to transmit the insulin signal by binding and regulating intracellular enzymes containing SH2 domains.
AB - IRS-1 is an insulin receptor substrate that undergoes tyrosine phosphorylation and associates with the phosphatidylinositol (PtdIns) 3′-kinase immediately after insulin stimulation. Recombinant IRS-1 protein was tyrosine phosphorylated by the insulin receptor in vitro and associated with the PtdIns 3′-kinase from lysates of quiescent 3T3 fibroblasts. Bacterial fusion proteins containing the src homology 2 domains (SH2 domains) of the 85-kDa subunit (p85) of the PtdIns 3′-kinase bound quantitatively to tyrosine phosphorylated, but not unphosphorylated, IRS-1, and this association was blocked by phosphotyrosine-containing synthetic peptides. Moreover, the phosphorylated peptides and the SH2 domains each inhibited binding of PtdIns 3′-kinase to IRS-1. Phosphorylated IRS-1 activated PtdIns 3′-kinase in anti-p85 immunoprecipitates in vitro, and this activation was blocked by SH2 domain fusion proteins. These data suggest that the interaction between PtdIns 3′-kinase and IRS-1 is mediated by tyrosine phosphorylated motifs on IRS-1 and the SH2 domains of p85, and IRS-1 activates PtdIns 3′-kinase by binding to the SH2 domains of p85. Thus, IRS-1 likely serves to transmit the insulin signal by binding and regulating intracellular enzymes containing SH2 domains.
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UR - http://www.scopus.com/inward/citedby.url?scp=0026489451&partnerID=8YFLogxK
M3 - Article
C2 - 1332046
AN - SCOPUS:0026489451
VL - 89
SP - 10350
EP - 10354
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 21
ER -