Epidermal growth factor induces coupling of protein-tyrosine phosphatase 1D to GRB2 via the COOH-terminal SH3 domain of GRB2.
The Src homology 2 (SH2) and SH3 domain-containing adaptor protein GRB2 and the SH2 domain-containing protein-tyrosine phosphatase 1D (PTP1D, also called SHPTP2, PTP2C, SHPTP3, Syp, or SHP-2) function as positive mediators of growth factor-induced mitogenesis. Epidermal growth factor (EGF) is a potent mitogen for MCF-10A human mammary epithelial cells and ... EGF receptor-expressing mouse NR6 fibroblasts. Western blot analysis of anti-PTP1D immune complexes derived from EGF-treated cells demonstrated a ligand-dependent coupling between the phosphatase and GRB2 in vivo. Probing of lysates from these cells with glutathione S-transferase (GST) fusion proteins corresponding to the individual domains of GRB2 revealed that this interaction was mediated exclusively by the COOH-terminal SH3 domain of GRB2. Importantly, a GST fusion protein containing the PTP1D SH2 domains was not capable of generating the EGF-induced linkage to GRB2. Additional experiments indicated that neither the binding of the nucleotide exchange factor Sos to GRB2 nor tyrosine phosphorylation of PTP1D was required for EGF-stimulated coupling of PTP1D to GRB2. This is the first demonstration of a growth factor- or cytokine-induced coupling of a protein through an SH3 domain and suggests that GRB2 functions to target PTP1D, in addition to Sos, to the plasma membrane in response to EGF.
Mesh Terms:
Adaptor Proteins, Signal Transducing, Animals, Cell Line, Epidermal Growth Factor, GRB2 Adaptor Protein, Humans, Mice, Protein Binding, Protein Tyrosine Phosphatases, Proteins, src Homology Domains
Adaptor Proteins, Signal Transducing, Animals, Cell Line, Epidermal Growth Factor, GRB2 Adaptor Protein, Humans, Mice, Protein Binding, Protein Tyrosine Phosphatases, Proteins, src Homology Domains
J. Biol. Chem.
Date: Aug. 30, 1996
PubMed ID: 8702859
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