Investigating the control principles behind formation of stress fibers by probing their response to external forces in silico

Cytoskeletal stress fibers (SFs) are important for stabilizing cell structure against external forces. While many insightful studies of SFs have been performed both in vivo and in vitro, comprehensive understanding of the underlying mechanisms for SF force generation and nucleation is still lacking. One of the obstacles to developing a theoretical framework to describe these processes is the experimental inaccessibility of informative microscopic quantities such as forces experienced and exerted by individual SFs. In our work, we modify the molecular dynamics simulation engine Cytosim [Nedelec et al. N. J. Phys. 2007] to apply external forces to parts of SFs. This customized computational tool allows us to investigate the effects of the applied forces on the nucleation rate and force response of SF-like structures. Our results provide insight into the possible control principles governing these processes and how cytoskeletal systems may take advantage of them to achieve adaptive force generation.