Dynein-inspired multilane exclusion process with open boundary conditions

TL;DR

This paper models dynein motor dynamics using a multilane exclusion process, revealing a novel phase diagram influenced by load conditions and aligning with experimental dwell time observations.

Contribution

It introduces a dynein-inspired multilane exclusion model with open boundaries, capturing load-dependent phase behavior and dwell time distributions.

Findings

Revealed a load-dependent phase diagram with LD, HD, and MC phases.

Observed dwell time distributions matching experimental data.

Compared dynein dynamics to TASEP, noting slower dwell times.

Abstract

Motivated by the sidewise motions of dynein motors shown in experiments, we use a variant of the exclusion process to model the multistep dynamics of dyneins on a cylinder with open ends. Due to the varied step sizes of the particles in a quasi-two-dimensional topology, we observe the emergence of a novel phase diagram depending on the various load conditions. Under high-load conditions, our numerical findings yield results similar to the TASEP model with the presence of all three standard TASEP phases, namely the low-density (LD), high-density (HD), and maximal-current (MC) phases. However, for medium- to low-load conditions, for all chosen influx and outflux rates, we only observe the LD and HD phases, and the maximal-current phase disappears. Further, we also measure the dynamics for a single dynein particle which is logarithmically slower than a TASEP particle with a shorter waiting time. Our results also confirm experimental observations of the dwell time distribution. The dwell time distribution for dyneins is exponential in less crowded conditions, whereas a double exponential emerges under overcrowded conditions.