title: Phase-plane analysis of the totally asymmetric simple exclusion process with binding kinetics and switching between antiparallel lanes.
abstract: Motor protein motion on biopolymers can be described by models related to the totally asymmetric simple exclusion process (TASEP). Inspired by experiments on the motion of kinesin-4 motors on antiparallel microtubule overlaps, we analyze a model incorporating the TASEP on two antiparallel lanes with binding kinetics and lane switching. We determine the steady-state motor density profiles using phase-plane analysis of the steady-state mean field equations and kinetic Monte Carlo simulations. We focus on the density-density phase plane, where we find an analytic solution to the mean field model. By studying the phase-space flows, we determine the model's fixed points and their changes with parameters. Phases previously identified for the single-lane model occur for low switching rate between lanes. We predict a multiple coexistence phase due to additional fixed points that appear as the switching rate increases: switching moves motors from the higher-density to the lower-density lane, causing local jamming and creating multiple domain walls. We determine the phase diagram of the model for both symmetric and general boundary conditions.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Hui-Shun
authors.initials: HS
authors.lastname: Kuan
authors.affiliation: Department of Physics, University of Colorado, Boulder, Colorado 80302, USA.
authors.forename: Meredith D
authors.initials: MD
authors.lastname: Betterton
mesh_terms: D007700:Kinetics; D008870:Microtubules / Q000378:metabolism; D008954:Models, Biological; D020409:Molecular Motor Proteins / Q000378:metabolism*; D009010:Monte Carlo Method; D009038:Motion; D011485:Protein Binding
chemical_list: D020409:Molecular Motor Proteins