title: Force-induced destabilization of focal adhesions at defined integrin spacings on nanostructured surfaces.
abstract: Focal adhesions are the anchoring points of cells to surfaces and are responsible for a large number of surface sensing processes. Nanopatterning studies have shown physiological changes in fibroblasts as a result of decreasing density of external binding ligands. The most striking of these changes is a decreased ability to form mature focal adhesions when lateral ligand distances exceed 76 nm. These changes are usually examined in the context of protein signaling and protein interactions. We show a physical explanation based on the balance between the forces acting on individual ligand connections and the reaction kinetics of those ligands. We propose three stability regimes for focal adhesions as a function of ligand spacing and applied stress: a stable regime, an unstable regime in which a large fraction of unbound protein causes adhesion disintegration, and a regime in which the applied force is too high to form an adhesion structure.
authors.affiliation: Department of New Materials and Biosystems, Max Planck Institute for Metals Research, Heisenbergstrasse 3, D70569 Stuttgart, Germany. debeer@mf.mpg.de
authors.forename: Alex G F
authors.initials: AG
authors.lastname: de Beer
authors.forename: E Ada
authors.initials: EA
authors.lastname: Cavalcanti-Adam
authors.forename: Günter
authors.initials: G
authors.lastname: Majer
authors.forename: M
authors.initials: M
authors.lastname: Lopez-García
authors.forename: H
authors.initials: H
authors.lastname: Kessler
authors.forename: Joachim P
authors.initials: JP
authors.lastname: Spatz
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D005353:Fibronectins / Q000737:chemistry; D022001:Focal Adhesions / Q000737:chemistry*; D016023:Integrins / Q000737:chemistry*; D007700:Kinetics; D008024:Ligands; D008823:Micelles; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D025941:Protein Interaction Mapping; D051381:Rats; D015398:Signal Transduction
chemical_list: D005353:Fibronectins; D016023:Integrins; D008024:Ligands; D008823:Micelles