Abstract

Almost all animal cells rely on actomyosin contractility as a mechanism for cell migration (with the notable exception of sperm cells which swim using undulating flagella). Oftentimes, what enables the actomyosin cortex to transmit forces to the extracellular environment and, hence, to generate directed motion is the adhesion of the cell to external structures. In fact, cell adhesion is one of three key stages in the classical description of 2D cell migration as a cycle of repetitive protrusion, adhesion and contraction.

In this talk, we will introduce the basic biophysics of cell adhesion and its role in the well-studied migration of cells over 2D surfaces. Next, we will present a recent mean-field model that describes the early formation of adhesion clusters (nascent adhesions) as a phase separation of ligand-receptor bonds (the ‘sticky feet’ mentioned in the title). This model is motivated by recent experiments investigating the adhesion of cells to lipid bilayers enriched with ligands of different affinities (or ‘stickiness’) [1]. If time allows, we will end by discussing recent efforts to expand the notion of protein friction (a measure of the adhesive strength between a moving cell and the substrate) to the case of cells migrating over complex substrates composed of both fluid and elastic layers.

Reference: [1] Oleg Mikhajlov, Ram M. Adar, Maria Tătulea-Codrean, Anne-Sophie Macé, John Manzi, Fanny Tabarin, Aude Battistella, Fahima di Federico, Jean-François Joanny, Guy Tran van Nhieu, Patricia Bassereau bioRxiv 2022.09.12.507658; https://doi.org/10.1101/2022.09.12.507658