Protein recruitment through indirect mechanochemical interactions

Some proteins have the ability to recruit other proteins from the cytosol to phospholipid membranes. This binding cooperativity plays a major role for the formation of protein patterns, which provide spatiotemporal control over many cellular processes. For example, Min oscillations guide the positioning of division axis in E. coli, and members of the Rho family of GTPases control contractility and migration of eukaryotic cells. However, the physical basis for this recruitment is still unclear. We suggest a generic feedback mechanism that explains how cooperativity can directly arise from mechanochemical coupling between the membrane and proteins. Such a mechanochemical coupling leads to membrane deformation, which in turn affects the affinity of proteins for the membrane, leading to a positive feedback in the protein binding rates. Our theory predicts that the mechanical properties of the membrane strongly affect protein recruitment, and therefore also protein pattern formation.