Polarity orientation of microtubules utilizing a dynein-based gliding assay.

The motor protein dynein was introduced into a nanotransport system. We oriented microtubules by their polarity, and immobilized them based on a dynein-microtubule gliding assay system. This system achieved unidirectional transport of kinesin-coated microbeads. In contrast to conventional kinesin-based orientation systems, the dynein-based system allowed the reverse motion of microtubules, resulting in an inversion of the orientation of microtubule polarity and thus reverse transport of kinesin-coated microbeads. This combined kinesin- and dynein-based system constitutes a new means to facilitate the bidirectional orientation of microtubules and transport of cargos in a nanofluidic system.