Focal adhesion kinase stabilizes the cytoskeleton

Biophys J. 2011 Nov 2;101(9):2131-8. doi: 10.1016/j.bpj.2011.09.043. Epub 2011 Nov 1.


Focal adhesion kinase (FAK) is a central focal adhesion protein that promotes focal adhesion turnover, but the role of FAK for cell mechanical stability is unknown. We measured the mechanical properties of wild-type (FAKwt), FAK-deficient (FAK-/-), FAK-silenced (siFAK), and siControl mouse embryonic fibroblasts by magnetic tweezer, atomic force microscopy, traction microscopy, and nanoscale particle tracking microrheology. FAK-deficient cells showed lower cell stiffness, reduced adhesion strength, and increased cytoskeletal dynamics compared to wild-type cells. These observations imply a reduced stability of the cytoskeleton in FAK-deficient cells. We attribute the reduced cytoskeletal stability to rho-kinase activation in FAK-deficient cells that suppresses the formation of ordered stress fiber bundles, enhances cortical actin distribution, and reduces cell spreading. In agreement with this interpretation is that cell stiffness and cytoskeletal stability in FAK-/- cells is partially restored to wild-type level after rho-kinase inhibition with Y27632.

Publication types

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

MeSH terms

  • Animals
  • Cell Adhesion / drug effects
  • Cytoskeleton / drug effects
  • Cytoskeleton / metabolism*
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Fibroblasts / enzymology*
  • Focal Adhesion Protein-Tyrosine Kinases / deficiency
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism*
  • Magnetic Phenomena
  • Mice
  • Microscopy, Atomic Force
  • Nanoparticles / ultrastructure
  • Protein Kinase Inhibitors / pharmacology
  • Rheology / drug effects
  • rho-Associated Kinases / antagonists & inhibitors
  • rho-Associated Kinases / metabolism


  • Protein Kinase Inhibitors
  • Focal Adhesion Protein-Tyrosine Kinases
  • rho-Associated Kinases