title: Crowding of receptors induces ring-like adhesions in model membranes.
abstract: The dynamics of formation of macromolecular structures in adherent membranes is a key to a number of cellular processes. However, the interplay between protein reaction kinetics, diffusion and the morphology of the growing domains, governed by membrane mediated interactions, is still poorly understood. Here we show, experimentally and in simulations, that a rich phase diagram emerges from the competition between binding, cooperativity, molecular crowding and membrane spreading. In the cellular context, the spontaneously-occurring organization of adhesion domains in ring-like morphologies is particularly interesting. These are stabilized by the crowding of bulky proteins, and the membrane-transmitted correlations between bonds. Depending on the density of the receptors, this phase may be circumvented, and instead, the adhesions may grow homogeneously in the contact zone between two membranes. If the development of adhesion occurs simultaneously with membrane spreading, much higher accumulation of binders can be achieved depending on the velocity of spreading. The mechanisms identified here, in the context of our mimetic model, may shed light on the structuring of adhesions in the contact zones between two living cells. This article is part of a Special Issue entitled: Mechanobiology.
authors.affiliation: Institut für Theoretische Physik and Cluster of Excellence: Engineering of Advanced Materials, Friedrich Alexander Universität Erlangen-Nürnberg, 91052 Erlangen, Germany; II. Institut für Theoretische Physik, Universität Stuttgart, 70569 Stuttgart, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Schmidt
authors.affiliation: Institut für Theoretische Physik and Cluster of Excellence: Engineering of Advanced Materials, Friedrich Alexander Universität Erlangen-Nürnberg, 91052 Erlangen, Germany; II. Institut für Theoretische Physik, Universität Stuttgart, 70569 Stuttgart, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Bihr
authors.affiliation: Institute of Complex Systems 7: Biomechanics, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany; Lehrstuhl für Zell- und Entwicklungsbiologie (Zoologie I), Biozentrum der Universität Würzburg, 97074 Würzburg, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Fenz
authors.affiliation: Institute of Complex Systems 7: Biomechanics, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Merkel
authors.affiliation: II. Institut für Theoretische Physik, Universität Stuttgart, 70569 Stuttgart, Germany.
authors.forename: Udo
authors.initials: U
authors.lastname: Seifert
authors.affiliation: Aix-Marseille Université, CNRS, CINaM UMR 7325, 13288 Marseille, France.
authors.forename: Kheya
authors.initials: K
authors.lastname: Sengupta
authors.affiliation: Institut für Theoretische Physik and Cluster of Excellence: Engineering of Advanced Materials, Friedrich Alexander Universität Erlangen-Nürnberg, 91052 Erlangen, Germany; Insitut Ruđer Bošković, 10000 Zagreb, Croatia. Electronic address: smith@physik.uni-erlangen.de.
authors.forename: Ana-Sunčana
authors.initials: AS
authors.lastname: Smith
mesh_terms: D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D008567:Membranes, Artificial; D008956:Models, Chemical
chemical_list: D008567:Membranes, Artificial
keywords: Adhesion dynamics; Cell adhesion; Crowding effects; Diffusion–reaction systems; Immunological synapse; Ligand-receptor bonds; Membrane fluctuations; Membrane transmitted correlations