Nature Cell Biology
3, 466 - 472 (2001)
Published online: 6 April 2001; | doi:10.1038/35074532
Force and focal adhesion assembly: a close relationship studied using elastic micropatterned substratesNathalie Q. Balaban1, Ulrich S. Schwarz2, Daniel Riveline3, Polina Goichberg1, Gila Tzur1, Ilana Sabanay1, Diana Mahalu4, Sam Safran2, Alexander Bershadsky1, Lia Addadi5
& Benjamin Geiger11
Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel
2
Department of Materials and Interfaces, The Weizmann Institute of Science, Rehovot, Israel
3
Laboratoire de Spectrometrie Physique, Universite Joseph Fourier, Grenoble, France
4
Braun Center for Submicron Semiconductor Research, The Weizmann Institute of Science, Rehovot, Israel
5
Department of Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
Correspondence should be addressed to Benjamin Geiger benny.geiger@weizmann.ac.ilMechanical forces play a major role in the regulation of cell adhesion and cytoskeletal organization. In order to explore the molecular mechanism underlying this regulation, we have investigated the relationship between local force applied by the cell to the substrate and the assembly of focal adhesions. A novel approach was developed for real-time, high-resolution measurements of forces applied by cells at single adhesion sites. This method combines micropatterning of elastomer substrates and fluorescence imaging of focal adhesions in live cells expressing GFP-tagged vinculin. Local forces are correlated with the orientation, total fluorescence intensity and area of the focal adhesions, indicating a constant stress of 5.5  2 nN m-2. The dynamics of the force-dependent modulation of focal adhesions were characterized by blocking actomyosin contractility and were found to be on a time scale of seconds. The results put clear constraints on the possible molecular mechanisms for the mechanosensory response of focal adhesions to applied force.
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