Computational model of integrin adhesion elongation under an actin fiber
Fig 4
Bundling of actin filaments stabilizes the assembly of nascent adhesions.
A. Snapshots of ligand-bound integrins (magenta) at 200 s of simulations, using no fiber (left) and a fiber (right; the pink rectangle indicates the location where the actin fiber overlaps with the adhesion). B. The average percentage of ligated integrins along the fiber short axis in the absence and presence of the fiber. C. Average percentage of ligated integrins using Pbundling = 0 (no fiber) and Pbundling = 1 (fiber). Errorbars indicate standard deviation from the mean. D. Average angle of the adhesion, relative to the direction of the actin fiber, using Pbundling = 0 (no fiber) and Pbundling = 1 (fiber). The angle is calculated from the direction of the first principal component of the 2D positions of ligated integrins, computed at each second of simulations between 100–500 s. Errorbars indicate standard deviation from the mean. E. Frequency of binding events using Pbundling = 0 (no fiber) and Pbundling = 1 (fiber). F. Distribution of total time spent by integrins in the ligated state, calculated as sum of the ligand-bound lifetimes of for each integrin over the course of 500 s of simulations, using Pbundling = 0 (no fiber) and Pbundling = 1 (fiber). All data are computed in the absence of actomyosin contractility, from 3 independent runs using k = 0.6 pN/nm.