Traffic of single-headed motor proteins KIF1A: effects of lane changing

TL;DR

This study models the movement of KIF1A motor proteins on microtubules as traffic flow, analyzing how lane-changing behavior affects motor flux, with predictions that depend on motor concentration and ATP hydrolysis rate.

Contribution

The paper extends a recent traffic model to include lane-changing effects for KIF1A motors, providing analytical and simulation results on flux variations.

Findings

Flux per lane can increase with lane-changing rate under certain conditions.

Predictions depend on motor concentration and ATP hydrolysis rate.

Model can be tested with in-vitro experiments.

Abstract

KIF1A kinesins are single-headed motor proteins which move on cylindrical nano-tubes called microtubules (MT). A normal MT consists of 13 protofilaments on which the equispaced motor binding sites form a periodic array. The collective movement of the kinesins on a MT is, therefore, analogous to vehicular traffic on multi-lane highways where each protofilament is the analogue of a single lane. Does lane-changing increase or decrease the motor flux per lane? We address this fundamental question here by appropriately extending a recent model [{\it Phys. Rev. E {\bf 75}, 041905 (2007)}]. By carrying out analytical calculations and computer simulations of this extended model, we predict that the flux per lane can increase or decrease with the increasing rate of lane changing, depending on the concentrations of motors and the rate of hydrolysis of ATP, the ``fuel'' molecules. Our predictions can be tested, in principle, by carrying out {\it in-vitro} experiments with fluorescently labelled KIF1A molecules.