Tyrosine phosphorylation of the β 4 integrin cytoplasmic domain mediates Shc signaling extracellular signal-regulated kinase and antagonizes formation of hemidesmosomes Journal Article


Authors: Dans, M.; Gagnoux-Palacios, L.; Blaikie, P.; Klein, S.; Mariotti, A.; Giancotti, F. G.
Article Title: Tyrosine phosphorylation of the β 4 integrin cytoplasmic domain mediates Shc signaling extracellular signal-regulated kinase and antagonizes formation of hemidesmosomes
Abstract: Ligation of the α 6β 4 integrin induces tyrosine phosphorylation of the β 4 cytoplasmic domain, followed by recruitment of the adaptor protein Shc and activation of mitogen-activated protein kinase cascades. We have used Far Western analysis and phosphopeptide competition assays to map the sites in the cytoplasmic domain of β 4 that are required for interaction with Shc. Our results indicate that, upon phosphorylation, Tyr 1440, or secondarily Tyr 1422, interacts with the SH2 domain of Shc, whereas Tyr 1526, or secondarily Tyr 1642, interacts with its phosphotyrosine binding (PTB) domain. An inactivating mutation in the PTB domain of Shc, but not one in its SH2 domain, suppresses the activation of Shc by α 6β 4. In addition, mutation of β 4 Tyr 1526, which binds to the PTB domain of Shc, but not of Tyr 1422 and Tyr 1440, which interact with its SH2 domain, abolishes the activation of ERK by α 6β 4. Phenylalanine substitution of the β 4 tyrosines able to interact with the SH2 or PTB domain of Shc does not affect incorporation of α 6β 4 in the hemidesmosomes of 804G cells. Exposure to the tyrosine phosphatase inhibitor orthovanadate increases tyrosine phosphorylation of β 4 and disrupts the hemidesmosomes of 804G cells expressing recombinant wild type β 4. This treatment, however, exerts a decreasing degree of inhibition on the hemidesmosomes of cells expressing versions of β 4 containing phenylalanine substitutions at Tyr 1422 and Tyr 1440, at Tyr 1526 and Tyr 1642, or at all four tyrosine phosphorylation sites. These results suggest that β 4 Tyr 1526 interacts in a phosphorylation-dependent manner with the PTB domain of Shc. This event is required for subsequent tyrosine phosphorylation of Shc and signaling to ERK but not formation of hemidesmosomes.
Keywords: signal transduction; mitogen activated protein kinase; protein phosphorylation; unclassified drug; gene mutation; human cell; protein domain; amino acid substitution; protein protein interaction; cell line; protein binding; transfection; tyrosine; phosphorylation; enzyme inhibitors; recombinant proteins; cytoplasm; binding sites; antigens, cd; protein structure; integrin alpha6; integrin; phenylalanine; antigens, surface; integrins; beta4 integrin; integrin beta4; phosphotyrosine; phosphopeptides; protein shc; hemidesmosome; integrin alpha6beta4; desmosomes; humans; human; priority journal; article; src homology domains; vanadates
Journal Title: Journal of Biological Chemistry
Volume: 276
Issue: 2
ISSN: 0021-9258
Publisher: American Society for Biochemistry and Molecular Biology  
Date Published: 2001-01-12
Start Page: 1494
End Page: 1502
Language: English
DOI: 10.1074/jbc.M008663200
PUBMED: 11044453
PROVIDER: scopus
DOI/URL:
Notes: Export Date: 21 May 2015 -- Source: Scopus
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MSK Authors
  1. Michael J Dans
    9 Dans
  2. Sharon Klein
    3 Klein