Microtubules’ Dynamic Apolar Lane Formation and Long-Range Order on a Supported Lipid Bilayer*

Microtubules (MTs) are a vital component of the eukaryotic cells’ cytoskeleton, forming a network utilized in cell transport. Kinesin motor proteins “walk” on MTs by converting chemical energy into mechanical energy to transport cargo. In this project, we studied MT-based active matter on a supported lipid bilayer. In a microtubule gliding assay configuration, kinesin motor proteins are immobilized by anchoring to a glass substrate. Here, MT behavior in the gliding assay method is compared with an assay in which motors are diffusing on a lipid bilayer. We find that the lipid membrane acts to promote filament-filament alignment within the gliding layer in high MT concentration. As a result, we observed dynamic apolar lane formation and long-range active nematic alignment. The enhanced collective motion of MTs with orientational order on different length scales is sensitive to MT concentration. These experiments are supported with continuum model simulations, together revealing that motors restructure on a lipid bilayer.