engleski

Crowding of receptors induces ring-like adhesions in model membranes

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 spontaneouslyoccurring organization of adhesion domains in ring- likemorphologies 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 adhesionsmay 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. Themechanisms identified here, in the context of our mimeticmodel, 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.

Cell adhesion, Immunological synapse, Adhesion dynamics, Membrane transmitted correlations, Ligand-receptor bonds, Crowding effects, Membrane fluctuations, Diffusion–reaction systems

S.I.: Mechanobiology.