Phase transitions in systems with two species of molecular motors

TL;DR

This paper models systems with two motor species on filaments, revealing phase transitions, symmetry breaking, hysteresis, and lane coexistence, with predictions testable experimentally.

Contribution

It introduces a theoretical driven lattice gas model capturing phase transitions and lane formation in two-species motor systems, a novel approach in this context.

Findings

Spontaneous symmetry breaking with motor exclusion

Hysteresis in motor current with concentration changes

Coexistence of opposite traffic lanes in multi-filament systems

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.