Evolving roles and dynamics for catch and slip bonds during adhesion cluster maturation.

Focal adhesions are the loci of cellular adhesion to the extracellular matrix. At these sites, various integrins forge connections between the intracellular cytoskeleton and the outside world; large patches of multiple types of integrins together grip hold of collagen, fibronectin, and other extracellular matrix components. A single focal adhesion will likely contain bonds whose lifetime increases with applied load (catch bonds), and bonds whose lifetime decreases with applied load (slip bonds).

Erratum: Persistence-Driven Durotaxis: Generic, Directed Motility in Rigidity Gradients [Phys. Rev. Lett. 118, 078103 (2017)].

This corrects the article DOI: 10.1103/PhysRevLett.118.

Persistence-Driven Durotaxis: Generic, Directed Motility in Rigidity Gradients.

Cells move differently on substrates with different rigidities: the persistence time of their motion is higher on stiffer substrates. We show that this behavior-in and of itself-results in a net flux of cells directed up a soft-to-stiff gradient. Using simple random walk models with varying persistence and stochastic simulations, we characterize the propensity to move in terms of the durotactic index also measured in experiments.

Contractile fibers and catch-bond clusters: a biological force sensor?

Catch bonds are cellular receptor-ligand pairs whose lifetime, counterintuitively, increases with increasing load. Although their existence was initially pure theoretical speculation, recent years have seen several experimental demonstrations of catch-bond behavior in biologically relevant and functional protein-protein bonds. Particularly notable among these established catch-bond formers is the integrin α5β1, the primary receptor for fibronectin and, as such, a crucial determinant for the characteristics of the mechanical coupling between cell and matrix.