Mean-field analysis of two-species TASEP with attachment and detachment

TL;DR

This paper develops a mean-field theoretical framework to analyze a two-species TASEP model with attachment and detachment, revealing phase transition properties and the relationship between domain walls of individual species and total density.

Contribution

It introduces a novel mean-field analysis for two-species TASEP with attachment and detachment, extending previous single-species models to better reflect biological motor transport.

Findings

Domain walls of individual species always appear with the total density wall.

The height of the total density domain wall equals the sum of individual species walls.

Phase diagrams illustrate the conditions for different density phases.

Abstract

In cells, most of cargos are transported by motor proteins along microtubule. Biophysically, unidirectional motion of large number of motor proteins along a single track can be described by totally asymmetric simple exclusion process (TASEP). From which many meaningful properties, such as the appearance of domain wall (defined as the borderline of high density and low density of motor protein along motion track) and boundary layers, can be obtained. However, it is biologically obvious that a single track may be occupied by different motor species. So previous studies based on TASEP of one particle species are not reasonable enough to find more detailed properties of the motion of motors along a single track. To address this problem, TASEP with two particle species is discussed in this study. Theoretical methods to get densities of each particle species are provided. Using these methods, phase transition related properties of particle densities are obtained. Our analysis show that domain wall and boundary layer of single species densities always appear simultaneously with those of the total particle density. The height of domain wall of total particle density is equal to the summation of those of single species. Phase diagrams for typical model parameters are also presented. The methods presented in this study can be generalized to analyze TASEP with more particle species.