Abstract
p97/Gab2 is a recently characterized member of a large family of scaffold proteins that play essential roles in signal transduction. Gab2 becomes tyrosine-phosphorylated in response to a variety of growth factors and forms multimolecular complexes with SH2 domain-containing signaling molecules such as the p85-regulatory subunit of the phosphoinositide-3-kinase (p85-PI3K), the tyrosine phosphatase SHP-2 and the adapter protein CrkL. To characterize the interactions between Gab2 and its SH2-containing binding partners, we designed a modified yeast two-hybrid system in which the Lyn tyrosine kinase is expressed in a regulated manner in yeast. Using this assay, we demonstrated that p97/Gab2 specifically interacts with the SH2 domains of PI3K, SHP-2 and CrkL. Interaction with p85-PI3K is mediated by tyrosine residues Y452, Y476 and Y584 of Gab2, while interaction with SHP-2 depends exclusively on tyrosine Y614. CrkL interaction is mediated by its SH2 domain recognizing Y266 and Y293, despite the latter being in a non-consensus (YTFK) environment.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptor Proteins, Signal Transducing*
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Cell Line
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Humans
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Intracellular Signaling Peptides and Proteins
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Nuclear Proteins / chemistry
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Nuclear Proteins / metabolism
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Peptides / metabolism
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Phosphatidylinositol 3-Kinases / chemistry
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Phosphatidylinositol 3-Kinases / metabolism
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Phosphoproteins / chemistry*
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Phosphoproteins / metabolism*
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Phosphorylation
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Phosphotyrosine / metabolism
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Protein Tyrosine Phosphatase, Non-Receptor Type 11
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Protein Tyrosine Phosphatase, Non-Receptor Type 6
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Protein Tyrosine Phosphatases / chemistry
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Protein Tyrosine Phosphatases / metabolism
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SH2 Domain-Containing Protein Tyrosine Phosphatases
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Saccharomyces cerevisiae / genetics
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Two-Hybrid System Techniques*
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src Homology Domains*
Substances
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Adaptor Proteins, Signal Transducing
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CRKL protein
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GAB2 protein, human
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Intracellular Signaling Peptides and Proteins
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Nuclear Proteins
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Peptides
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Phosphoproteins
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Phosphotyrosine
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PTPN11 protein, human
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PTPN6 protein, human
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Protein Tyrosine Phosphatase, Non-Receptor Type 11
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Protein Tyrosine Phosphatase, Non-Receptor Type 6
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Protein Tyrosine Phosphatases
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SH2 Domain-Containing Protein Tyrosine Phosphatases