Modeling of the collective motion of microtubules with mobile kinesin motors.*

The microtubule gliding assay, an in-vitro technique commonly used to study motility of motor proteins, also provides an opportunity to study the collective motion of microtubules as an active fluid. Computational modeling of this system usually studies the microtubule positions assuming a spatially uniform distribution of the motor proteins, which models the experiments where the positions of motors are fixed. We explore a modified setup where kinesin motors are mobile. We use Brownian Dynamics simulations to model the collective motions of microtubules with explicit consideration of the concentration of the motors. We investigate spontaneous dynamical spatial variation in microtubule density that is introduced by allowing diffusion and transport of the motors. We also address how the mobile kinesin motors change the phase diagram as a function of kinesin and microtubule densities.