Focal adhesion kinase modulates cell adhesion strengthening via integrin activation

Mol Biol Cell. 2009 May;20(9):2508-19. doi: 10.1091/mbc.e08-01-0076. Epub 2009 Mar 18.

Abstract

Focal adhesion kinase (FAK) is an essential nonreceptor tyrosine kinase regulating cell migration, adhesive signaling, and mechanosensing. Using FAK-null cells expressing FAK under an inducible promoter, we demonstrate that FAK regulates the time-dependent generation of adhesive forces. During the early stages of adhesion, FAK expression in FAK-null cells enhances integrin activation to promote integrin binding and, hence, the adhesion strengthening rate. Importantly, FAK expression regulated integrin activation, and talin was required for the FAK-dependent effects. A role for FAK in integrin activation was confirmed in human fibroblasts with knocked-down FAK expression. The FAK autophosphorylation Y397 site was required for the enhancements in adhesion strengthening and integrin-binding responses. This work demonstrates a novel role for FAK in integrin activation and the time-dependent generation of cell-ECM forces.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Biomechanical Phenomena / drug effects
  • Cell Adhesion / drug effects
  • Fibroblasts / cytology*
  • Fibroblasts / drug effects
  • Fibroblasts / enzymology*
  • Fibronectins / metabolism
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism*
  • Gene Knockdown Techniques
  • Humans
  • Integrin alpha5beta1 / metabolism*
  • Integrins / metabolism*
  • Kinetics
  • Mice
  • Phosphorylation / drug effects
  • Phosphotyrosine / metabolism
  • Protein Binding / drug effects
  • Solubility / drug effects
  • Talin / metabolism
  • Tetracycline / pharmacology
  • Vinculin / metabolism

Substances

  • Fibronectins
  • Integrin alpha5beta1
  • Integrins
  • Talin
  • Vinculin
  • Phosphotyrosine
  • Focal Adhesion Protein-Tyrosine Kinases
  • Tetracycline