A model for bidirectional traffic of cytoskeletal motors

TL;DR

This paper presents a stochastic lattice gas model simulating bidirectional motor traffic on cytoskeletal filaments, revealing conditions for clustering and the importance of filament coupling for efficient transport.

Contribution

It introduces a novel two-lane model capturing bidirectional motor dynamics and analyzes cluster formation and the effects of filament coupling.

Findings

Cluster formation occurs at all densities for large systems.

Coupling multiple filaments enhances cluster formation.

High binding affinity leads to jam-like states.

Abstract

We introduce a stochastic lattice gas model including two particle species and two parallel lanes. One lane with exclusion interaction and directed motion and the other lane without exclusion and unbiased diffusion, mimicking a micotubule filament and the surrounding solution. For a high binding affinity to the filament, jam-like situations dominate the system's behaviour. The fundamental process of position exchange of two particles is approximated. In the case of a many-particle system, we were able to identify a regime in which the system is rather homogenous presenting only small accumulations of particles and a regime in which an important fraction of all particles accumulates in the same cluster. Numerical data proposes that this cluster formation will occur at all densities for large system sizes. Coupling of several filaments leads to an enhanced cluster formation compared to the uncoupled system, suggesting that efficient bidirectional transport on one-dimensional filaments relies on long-ranged interactions and track formation.