Non-SH2 domains within insulin receptor substrate-1 and SHC mediate their phosphotyrosine-dependent interaction with the NPEY motif of the insulin-like growth factor I receptor.
Insulin receptor substrate-1 (IRS-1) and SHC become rapidly phosphorylated upon tyrosines after insulin-like growth factor I receptor (IGFIR) activation. In this study we demonstrate that IRS-1, SHC, and the p85 subunit of phosphatidylinositol 3-kinase interact directly and specifically with the IGFIR. The interaction of all three proteins is dependent upon IGFIR kinase activity and, furthermore, substitution of Tyr-950 with Phe within the NPEY motif of the IGFIR eliminated interaction with both SHC and IRS-1 but had no effect upon p85 interaction. We show that residues 160-516 of IRS-1 and 1-238 of SHC are sufficient and necessary for receptor interaction in the yeast two-hybrid assay. We also demonstrate a direct in vitro interaction between the IGFIR and a fusion protein containing SHC amino acids 1-238. No interaction was observed with a SHC protein containing only the SH2 domain. We conclude that SHC and IRS-1 interact with the tyrosine-phosphorylated NPEY motif of the IGFIR, and that both proteins interact via related motifs located in their amino termini. We conclude that the interactions of SHC and IRS-1 with the IGFIR are similar to those which we have previously defined with the insulin receptor.
Craparo
A
A
Department of Physiology, University of Maryland School of Medicine, Baltimore 21201, USA.
O'Neill
T J
TJ
Gustafson
T A
TA
D048868:Adaptor Proteins, Signal Transducing; D001665:Binding Sites; D002455:Cell Division; D051380:GRB2 Adaptor Protein; D055504:Insulin Receptor Substrate Proteins; D019869:Phosphatidylinositol 3-Kinases; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism; D019000:Phosphotyrosine; D011506:Proteins / Q000378:metabolism*; D017526:Receptor, IGF Type 1 / Q000378:metabolism*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D051380:GRB2 Adaptor Protein; D055504:Insulin Receptor Substrate Proteins; D010750:Phosphoproteins; D011506:Proteins; D019000:Phosphotyrosine; D014443:Tyrosine; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D017526:Receptor, IGF Type 1