2013/12/19 by Shenshen Wang, Peter G. Wolynes
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Actin #Cellular Mechanics and Interactions #Cooperativity #Coupling (piping) #Cytoskeleton #Directionality #Micro and Nano Robotics #Microtubule and mitosis dynamics #Molecular motor #Motor protein #Percolation (cognitive psychology) #Protein filament #Thermal fluctuations #cond-mat.soft #physics.bio-ph #q-bio.SC
paper · pdf · doi:10.1063/1.4848657
published as J. Chem. Phys. 139, 235103 (2013) · 11 pages, 5 figures
openalex publication_date 2013/12/19 · arxiv created 2014/12/19 · arxiv updated 2014/12/22 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Cytoskeletal networks, which are essentially motor-filament assemblies, play a major role in many developmental processes involving structural remodeling and shape changes. These are achieved by nonequilibrium self-organization processes that generate functional patterns and drive intracellular transport. We construct a minimal physical model that incorporates the coupling between nonlinear elastic responses of individual filaments and force-dependent motor action. By performing stochastic simulations we show that the interplay of motor processes, described as driving anti-correlated motion of the network vertices, and the network connectivity, which determines the percolation character of the structure, can indeed capture the dynamical and structural cooperativity which gives rise to diverse patterns observed experimentally. The buckling instability of individual filaments is found to play a key role in localizing collapse events due to local force imbalance. Motor-driven buckling-induced node aggregation provides a dynamic mechanism that stabilizes the two-dimensional patterns below the apparent static percolation limit. Coordinated motor action is also shown to suppress random thermal noise on large time scales, the two-dimensional configuration that the system starts with thus remaining planar during the structural development. By carrying out similar simulations on a three-dimensional anchored network, we find that the myosin-driven isotropic contraction of a well-connected actin network, when combined with mechanical anchoring that confers directionality to the collective motion, may represent a novel mechanism of intracellular transport, as revealed by chromosome translocation in the starfish oocyte.