β4 integrin activates a Shp2-Src signaling pathway that sustains HGF-induced anchorage-independent growth

Andrea Bertotti, Paolo M. Comoglio, Livio Trusolino

Research output: Contribution to journalArticle

Abstract

Despite being a cell-matrix adhesion molecule, β4 integrin can prompt the multiplication of neoplastic cells dislodged from their substrates (anchorage-independent growth). However, the molecular events underlying this atypical behavior remain partly unexplored. We found that activation of the Met receptor for hepatocyte growth factor results in the tyrosine phosphorylation of β4, which is instrumental for integrin-mediated recruitment of the tyrosine phosphatase Shp2. Shp2 binding to β4 enhances the activation of Src, which, in turn, phosphorylates the multiadaptor Gab1 predominantly on consensus sites for Grb2 association, leading to privileged stimulation of the Ras-extracellular signal-regulated kinase (ERK) cascade. This signaling axis can be inhibited by small interfering RNA-mediated β4 depletion, by a β4 mutant unable to bind Shp2, and by pharmacological and genetic inhibition of Shp2 or Src. Preservation of the β4 docking sites for Shp2 as well as the integrity of Shp2, Src, or ERK activity are required for the β4-mediated induction of anchorage-independent growth. These results unravel a novel pathway whereby β4 directs tyrosine kinase-based signals toward adhesion-unrelated outcomes.

Original languageEnglish
Pages (from-to)993-1003
Number of pages11
JournalJournal of Cell Biology
Volume175
Issue number6
DOIs
Publication statusPublished - Dec 18 2006

ASJC Scopus subject areas

  • Cell Biology

Fingerprint Dive into the research topics of 'β4 integrin activates a Shp2-Src signaling pathway that sustains HGF-induced anchorage-independent growth'. Together they form a unique fingerprint.

  • Cite this