Interleukin (IL)-3 and granulocyte/macrophage colony-stimulating factor, but not IL-4, induce tyrosine phosphorylation, activation, and association of SHPTP2 with Grb2 and phosphatidylinositol 3'-kinase.
Binding of interleukin (IL)-3 and granulocyte/macrophage colony-stimulating factor (GM-CSF) to their high affinity cell surface receptors induces tyrosine phosphorylation of a similar set of protein substrates. We have identified one of these common substrates (p70) as the protein-tyrosine phosphatase SHPTP2. The Src homology 2 (SH2) domain of the adaptor protein Grb2 bound with high affinity to tyrosine-phosphorylated SHPTP2 following treatment of cells with IL-3 or GM-CSF, but not IL-4. This interaction was inhibited by two phosphotyrosine peptides, based on sequences within SHPTP2, which conform to the postulated consensus sequence for Grb2 SH2 recognition. Following treatment with IL-3 or GM-CSF, but not IL-4, SHPTP2 co-immunoprecipitated with antibodies directed against the p85 subunit of PI 3'-kinase. This was partially blocked by the same phosphopeptides that blocked Grb2-SH2 binding to SHPTP2. Importantly, treatment with IL-3 resulted in a 2-3-fold increase in SHPTP2 phosphatase activity. These results suggest that SHPTP2 may play an important role in integrating signals from the IL-3 and GM-CSF receptors to both Ras and PI 3'-kinase.
Welham
M J
MJ
Biomedical Research Centre, University of British Columbia, Vancouver, Canada.
Dechert
U
U
Leslie
K B
KB
Jirik
F
F
Schrader
J W
JW
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D002478:Cells, Cultured; D051380:GRB2 Adaptor Protein; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D066298:In Vitro Techniques; D007377:Interleukin-3 / Q000494:pharmacology*; D015847:Interleukin-4 / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases; D010748:Phosphopeptides / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism; D019000:Phosphotyrosine; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D051380:GRB2 Adaptor Protein; C495949:Grb2 protein, mouse; D007377:Interleukin-3; D047908:Intracellular Signaling Peptides and Proteins; D010455:Peptides; D010748:Phosphopeptides; D011506:Proteins; D015847:Interleukin-4; D019000:Phosphotyrosine; D014443:Tyrosine; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases; C516725:Ptpn11 protein, mouse; C509248:Ptpn6 protein, mouse; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases