Boundary-bulk interplay of molecular motor traffic flow through a compartment

TL;DR

This paper models motor protein traffic on filaments within a compartment, revealing how detachment rates influence density profiles and lead to complex, non-monotonic behaviors and coexistence of high and low density regions.

Contribution

It introduces a lattice model incorporating boundary and bulk interactions for motor proteins, highlighting the impact of detachment rates on system behavior, which is a novel extension of ASEP.

Findings

Detachment rate significantly affects density profiles.

Non-monotonic density behaviors observed with varying detachment rates.

Coexistence of high and low density regions on the filament.

Abstract

The flow of motor proteins on a filamental track is modelled within the the framework of lattice driven diffusive systems. Motors, considered as hopping particles, perform a highly biased asymmetric exclusion process when bound to the filament. With a certain rate, they detach from the filament and execute unbiased random walk in the bulk which is considered as a closed cubic compartment. Motors are injected (extracted) from the leftmost (rightmost) site of the filament located along the symmetry axis of the compartment. We explore the transport properties of this system and investigate the bulk-boundary interplay on the system stationary states. It is shown that the detachment rate notably affects the system properties. In particular and in contrast to ASEP, it is shown that the density profile of bound particles exhibit different types of non monotonic behaviours when the detachment rate varies. It is shown that in certain situations, the density profile of the filament consists of coexisting high and low regions.