Microtubule length dependence of motor traffic in cells

TL;DR

This paper investigates how the length of microtubules influences motor protein traffic jams, revealing a critical length threshold and how attachment/detachment rates affect jam formation.

Contribution

It introduces a length-dependent analysis of motor traffic, identifying a critical microtubule length for jam formation and how rates influence this threshold.

Findings

Traffic jams occur only when microtubule length exceeds a critical value.

Jammed length increases with total microtubule length.

Critical length increases with detachment rate and decreases with attachment rate.

Abstract

In living cells, motor proteins, such as kinesin and dynein can move processively along microtubule (MT), and also detach from or attach to MT stochastically. Experiments have found that, the traffic of motor might be jammed, and various theoretical models have been designed to understand this traffic jam phenomenon. But previous studies mainly focus on motor attachment/detachment rate dependent properties. Recent experiment of Leduc {\it et al.} found that the traffic jam formation of motor protein kinesin depends also on the length of MT [Proc. Natl. Acad. Sci. U.S.A. {\bf 109}, 6100-6105 (2012)]. In this study, the MT length dependent properties of motor traffic will be analyzed. We found that MT length has one {\it critical value} $N_c$, traffic jam occurs only when MT length $N>N_c$. The jammed length of MT increases with total MT length, while the non-jammed MT length might not change monotonically with the total MT length. The critical value $N_c$ increases with motor detachment rate from MT, but decreases with motor attachment rate to MT.