Phase transitions in systems with two species of molecular motors

Max-Planck-Institut für Kolloid- und Grenzflächenforschung 14424 Potsdam, Germany

Received: 26 November 2003
Accepted: 4 February 2004

Abstract

Systems with two species of active molecular motors moving on (cytoskeletal) filaments into opposite directions are studied theoretically using driven lattice gas models. The motors can unbind from and rebind to the filaments. Two motors are more likely to bind on adjacent filament sites if they belong to the same species. These systems exhibit i) continuous phase transitions towards states with spontaneously broken symmetry, where one motor species is largely excluded from the filament, ii) hysteresis of the total current upon varying the relative concentrations of the two motor species, and iii) coexistence of traffic lanes with opposite directionality in multi-filament systems. These theoretical predictions should be experimentally accessible.