Visualizing the interior architecture of focal adhesions with high-resolution traction maps

Nano Lett. 2015 Apr 8;15(4):2220-8. doi: 10.1021/nl5047335. Epub 2015 Mar 23.


Focal adhesions (FAs) are micron-sized protein assemblies that coordinate cell adhesion, migration, and mechanotransduction. How the many proteins within FAs are organized into force sensing and transmitting structures is poorly understood. We combined fluorescent molecular tension sensors with super-resolution light microscopy to visualize traction forces within FAs with <100 nm spatial resolution. We find that αvβ3 integrin selectively localizes to high force regions. Paxillin, which is not generally considered to play a direct role in force transmission, shows a higher degree of spatial correlation with force than vinculin, talin, or α-actinin, proteins with hypothesized roles as force transducers. These observations suggest that αvβ3 integrin and paxillin may play important roles in mechanotransduction.

Keywords: Mechanobiology; focal adhesion; integrin; molecular tension sensor; super-resolution; traction force microscopy.

Publication types

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

MeSH terms

  • Adhesiveness
  • Animals
  • Cells, Cultured
  • Cytoskeletal Proteins / metabolism*
  • Fluorescence Resonance Energy Transfer / methods
  • Focal Adhesions / physiology*
  • Humans
  • Image Enhancement / methods
  • Mechanotransduction, Cellular / physiology*
  • Membrane Proteins / metabolism*
  • Mice
  • Microscopy, Fluorescence / methods*
  • Molecular Imaging / methods*
  • Stress, Mechanical
  • Tensile Strength / physiology


  • Cytoskeletal Proteins
  • Membrane Proteins