Figure 1.

Schematic of the models. (a) The single molecules model. A single talin molecule links between an actin filament moving with the velocity v and integrin bound to the elastic substrate with the spring constant k. The talin link, which has the lifetime τ, transmits a force f to the substrate and is extended by Δl between the moving actin filament and the substrate deformed by Δx. (b) The cluster model. Multiple talin molecules link between actin filaments moving with the velocity v and an integrin cluster with a diameter a. The integrin cluster is bound to the elastic substrate whose elastic modulus is E. Each talin link has the lifetime τ, transmits a force f to the substrate and is extended by Δl between moving actin filaments and the deformed substrate. (c) An example of the displacement field for the x–z cross section (the plane denoted by dotted lines in the (b)) of the substrate. The parameters used are a = 500 nm, f = 2 pN, n = 10 and E = 1 kPa. The black bar indicates the position of the integrin cluster. (Online version in colour.)