title: Spontaneous symmetry breaking for geometrical trajectories of actin-based motility in three dimensions.
abstract: Actin-based motility is important for many cellular processes. In this article we extend our previous studies of an actin-propelled circular disk in two dimensions to an actin-propelled spherical bead in three dimensions. We find that for an achiral load the couplings between the motion of the load and the actin network induce a series of bifurcations, starting with a transition from rest to moving state, followed by a transition from straight to planar curves, and finally a further transition from motion in a plane to one with torsion. To address the intriguing, experimentally observed chiral motility of the bacterium Listeria monocytogenes, we also study the motility of a spherical load with a built-in chirality. For such a chiral load, stable circular trajectories are no longer found in numerical simulations. Instead, helical trajectories with handedness that depends on the chirality of the load are found. Our results reveal the relation between the symmetry of actin network and the trajectories of actin-propelled loads.
authors: Laboratory for Physical Biology, RIKEN Quantitative Biology Center, Kobe 650-0047, Japan.
authors: Fu-Lai
authors: FL
authors: Wen
authors: Institute of Physics, Academia Sinica, Taipei 11529, Taiwan, R.O.C.|Department of Physics, National Central University, Taoyuan 32001, Taiwan, R.O.C.
authors: Kwan-Tai
authors: KT
authors: Leung
authors: Institute of Physics, Academia Sinica, Taipei 11529, Taiwan, R.O.C.|Department of Physics, National Central University, Taoyuan 32001, Taiwan, R.O.C.|Physics Division, National Center for Theoretical Sciences, Hsinchu 30013, Taiwan, R.O.C.
authors: Hsuan-Yi
authors: HY
authors: Chen
mesh_terms: D000199:Actins / Q000378:metabolism*; D008089:Listeria monocytogenes / Q000166:cytology / Q000502:physiology*; D008954:Models, Biological; D009038:Motion
chemical_list: D000199:Actins