title: Cooperativity in adhesion cluster formation during initial cell adhesion.
abstract: We have studied the initial phase of cell adhesion as a function of the lateral organization of individual integrin molecules with single-cell force microscopy. Nanostructures, consisting of hexagonally ordered gold dots, were prepared with diblock-copolymer micelle lithography and functionalized with arginine- glycine-aspartate peptides, thus defining integrin position with nanometer resolution. Adhesion strength was characterized with an atomic force microscope and both cell detachment forces and work of detachment showed a reinforcement of adhesion if the distance between integrin molecules was <70 nm. This reinforcement had already occurred at cell-substrate contact times <5 min. We believe our results show quantitatively the relevance of the distance between adjacent integrin binding sites rather than their density. Furthermore, we propose a model describing the cooperative stabilization of early integrin clusters as a function of receptor patterning at the nanoscale.
authors.affiliation: Department of New Materials and Biosystems, Max-Planck-Institute for Metals Research, Stuttgart, Germany. selhuber@nbi.dk
authors.forename: Christine
authors.initials: C
authors.lastname: Selhuber-Unkel
authors.forename: Mónica
authors.initials: M
authors.lastname: López-García
authors.forename: Horst
authors.initials: H
authors.lastname: Kessler
authors.forename: Joachim P
authors.initials: JP
authors.lastname: Spatz
mesh_terms: D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002448:Cell Adhesion; D002460:Cell Line; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D016023:Integrins / Q000378:metabolism*; D008823:Micelles; D049329:Nanostructures; D010456:Peptides, Cyclic / Q000378:metabolism; D051381:Rats
chemical_list: D016023:Integrins; D008823:Micelles; D010456:Peptides, Cyclic; C507169:cyclic arginine-glycine-aspartic acid peptide