title: The dynamics of filament assembly define cytoskeletal network morphology.
abstract: The actin cytoskeleton is a key component in the machinery of eukaryotic cells, and it self-assembles out of equilibrium into a wide variety of biologically crucial structures. Although the molecular mechanisms involved are well characterized, the physical principles governing the spatial arrangement of actin filaments are not understood. Here we propose that the dynamics of actin network assembly from growing filaments results from a competition between diffusion, bundling and steric hindrance, and is responsible for the range of observed morphologies. Our model and simulations thus predict an abrupt dynamical transition between homogeneous and strongly bundled networks as a function of the actin polymerization rate. This suggests that cells may effect dramatic changes to their internal architecture through minute modifications of their nonequilibrium dynamics. Our results are consistent with available experimental data.
authors.affiliation: LPTMS, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France.
authors.forename: Giulia
authors.initials: G
authors.lastname: Foffano
authors.affiliation: Laboratoire de Physique Théorique de la Matière Condensée, UPMC, CNRS UMR 7600, Sorbonne Universités, 4 Place Jussieu, 75252 Paris Cedex 05, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Levernier
authors.affiliation: LPTMS, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France.
authors.forename: Martin
authors.identifier: 0000-0002-2307-1106
authors.initials: M
authors.lastname: Lenz
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry / Q000378:metabolism*; D000199:Actins / Q000737:chemistry / Q000378:metabolism; D000465:Algorithms; D003198:Computer Simulation; D007700:Kinetics; D008954:Models, Biological; D058105:Polymerization
chemical_list: D000199:Actins