Multiple in vivo phosphorylated tyrosine phosphatase SHP-2 engages binding to Grb2 via tyrosine 584.
SHP-2 (also named PTP1D, syp, or SH-PTP2) has been identified as a phosphotyrosine phosphatase comprising two src-homology-2 (SH2) domains. Upon growth factor stimulation, SHP-2 becomes tyrosine phosphorylated, thereby increasing its catalytic activity. Here, we identified SHP-2 to be phosphorylated on multiple tyrosine residues in response to different stimuli and unmasked ... the carboxyl-terminal tyrosine 584 as a major phosphorylation site in human cell lines. Tyrosine 584 shares, together with tyrosine 546, the consensus sequence pY-X-N-X, a characteristic of potential binding sites for the SH2 domain of growth factor receptor-bound protein 2 (Grb2). We show here that mutation of tyrosine 584, but not tyrosine 546, to phenylalanine totally abolished the binding of Grb2 to SHP-2. By using a systematic mutagenesis approach, phosphorylation of additional tyrosines in each of the SH2 domains of SHP-2 was detected after coexpression of epidermal growth factor receptor, but not after coexpression of platelet-derived growth factor receptor, whereas tyrosine 263 located in the interspace between SH2 and catalytic domain appears to be exclusively recognized by platelet-derived growth factor receptor. Immunoprecipitation of SHP-2 from a panel of mammary carcinoma cell lines copurifies several tyrosine phosphorylated proteins; the most prominent band has an apparent molecular weight of M(r) 115,000.
Mesh Terms:
Adaptor Proteins, Signal Transducing, Animals, Blotting, Western, Cell Line, Electrophoresis, Gel, Two-Dimensional, GRB2 Adaptor Protein, Humans, Intracellular Signaling Peptides and Proteins, Kidney, Mutagenesis, Phosphorylation, Phosphotyrosine, Protein Binding, Protein Tyrosine Phosphatase, Non-Receptor Type 11, Protein Tyrosine Phosphatase, Non-Receptor Type 6, Protein Tyrosine Phosphatases, Proteins, Rabbits, Receptor, Epidermal Growth Factor, SH2 Domain-Containing Protein Tyrosine Phosphatases, Serine, Signal Transduction, Threonine, Tyrosine, src Homology Domains
Adaptor Proteins, Signal Transducing, Animals, Blotting, Western, Cell Line, Electrophoresis, Gel, Two-Dimensional, GRB2 Adaptor Protein, Humans, Intracellular Signaling Peptides and Proteins, Kidney, Mutagenesis, Phosphorylation, Phosphotyrosine, Protein Binding, Protein Tyrosine Phosphatase, Non-Receptor Type 11, Protein Tyrosine Phosphatase, Non-Receptor Type 6, Protein Tyrosine Phosphatases, Proteins, Rabbits, Receptor, Epidermal Growth Factor, SH2 Domain-Containing Protein Tyrosine Phosphatases, Serine, Signal Transduction, Threonine, Tyrosine, src Homology Domains
Cell Growth Differ.
Date: Dec. 01, 1996
PubMed ID: 8959326
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