Fig. 3: Actin filament density (or F-actin concentration) sensitively regulates the elastic properties of the branched actin network.
a lamellipodium drives cell migration through confining extracellular microenvironments. b Young’s moduli: E1, E2, and E3 are in the transverse direction (x direction in Fig. 2c), cell movement direction (y direction in Fig. 2c), and the out-of-plane direction (z direction in Fig. 2c), respectively. c Shear moduli: G12 is in the xy plane, G23 is in the yz plane, and G31 is in the xz plane. d Poisson’s ratios are defined as \(v_{ij} = - \varepsilon _i/\varepsilon _j\), where \(\varepsilon _i\) is the strain in the i direction when uniaxial stress is applied in the j direction. The data in figures for power-law fit are mean values calculated from about 30 stochastic models with the same set of parameters of intracellular proteins, and the error bars are the standard deviations of the results. The numbers near the straight fitting lines in panels b and c are the slopes of these power-law fit functions.
