From aggressive driving to molecular motor traffic

TL;DR

This paper develops a cellular automata model for dynein motor traffic, incorporating unique step size features and attachment-detachment dynamics, providing insights into intracellular motor transport mechanisms.

Contribution

It introduces a novel automata-based model for dynein motors, extending vehicular traffic models to include biological motor behaviors and compares dynein with kinesin transport efficiencies.

Findings

Analytical and simulation results reveal phase coexistence of high and low density motor regions.

The model captures the impact of attachment and detachment on motor traffic phases.

Dynein and kinesin efficiencies vary with model parameters, highlighting different transport regimes.

Abstract

Motivated by recent experimental results for the step sizes of dynein motor proteins, we develope a cellular automata model for intra-cellular traffic of dynein motors incorporating special features of the hindrance-dependent step size of the individual motors. We begin by investigating the properties of the aggressive driving model (ADM), a simple cellular automata-based model of vehicular traffic, a unique feature of which is that it allows a natural extension to capture the essential features of dynein motor traffic. We first calculate several collective properties of the ADM, under both periodic and open boundary conditions, analytically using two different mean-field approaches as well as by carrying out computer simulations. Then we extend the ADM by incorporating the possibilities of attachment and detachment of motors on the track which is a common feature of a large class of motor proteins that are collectively referred to as cytoskeletal motors. The interplay of the boundary and bulk dynamics of attachment and detachment of the motors to the track gives rise a phase where high and low density phases separated by a stable domain wall coexist. We also compare and contrast our results with the model of Parmeggiani et. al. (Phys. Rev. Lett. {\bf 90}, 086601 (2003)) which can be regarded as a minimal model for traffic of a closely related family of motor proteins called kinesin. Finally, we compare the transportation efficiencies of dynein and kinesin motors over a range of values of the model parameters.