title: Identification of cadherin tyrosine residues that are phosphorylated and mediate Shc association.
abstract: Previously, we reported association of the adaptor protein Shc through its SH2 domain with the cytoplasmic domain of the adhesion molecule cadherin (Xu et al. [1997] J. Biol. Chem. 272:13463-13466). This association was dependent on tyrosine phosphorylation of cadherin and could be modulated by extracellular Ca(2+) and epidermal growth factor in intact cells. There are six tyrosine residues in the cytoplasmic domain of cadherin. To define the tyrosine residue(s) that mediate Shc recognition, site-directed mutagenesis was employed to alter Tyr851 and/or Tyr883 in cadherin, which both conform to a predicted Shc SH2 domain recognition sequence. Mutation of either Tyr851 or Tyr883, but mostly the latter, decreased Src phosphorylation of cadherin and the binding of Shc to cadherin, as determined by Sepharose bead binding and gel overlay assays. Of the two tyrosine residues, Tyr883 is the major Src phosphorylation and Shc binding site. However, the double mutant (Tyr851, 883 Phe) exhibited less Shc association than the single Tyr883 Phe mutant, suggesting a role for Tyr851 also. In addition, the binding of Shc to the cadherin cytoplasmic domain was competitively inhibited by tyrosine phosphorylated peptides containing either Tyr851 or Tyr883, but not by the corresponding non-phosphorylated peptides. Mutation of Tyr851 and/or Tyr883 did not alter the capacity of the cytoplasmic domain of cadherin to bind beta-catenin in vitro. However, Shc binding to cadherin did negatively influence beta-catenin binding to the same molecule.
authors.affiliation: Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.forename: G
authors.initials: G
authors.lastname: Carpenter
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D001665:Binding Sites; D015820:Cadherins / Q000737:chemistry* / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005982:Glutathione Transferase / Q000378:metabolism; D051379:Mice; D016297:Mutagenesis, Site-Directed; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism; D010766:Phosphorylation; D010957:Plasmids; D011506:Proteins / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012685:Sepharose / Q000378:metabolism; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D015534:Trans-Activators; D014443:Tyrosine / Q000737:chemistry*; D051176:beta Catenin; D019061:src-Family Kinases / Q000494:pharmacology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; C495267:CTNNB1 protein, mouse; D015820:Cadherins; D003598:Cytoskeletal Proteins; D010455:Peptides; D011506:Proteins; D011993:Recombinant Fusion Proteins; D055765:Shc Signaling Adaptor Proteins; C528034:Shc1 protein, mouse; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D015534:Trans-Activators; D051176:beta Catenin; D014443:Tyrosine; D012685:Sepharose; D005982:Glutathione Transferase; D019061:src-Family Kinases