Resolving Endosome Rotation in Intracellular Trafficking

Intracellular cargos are known to be transported by molecular motors, but the mechanisms by which different groups of motor proteins maneuver cargos through the complex microtubule network remain elusive. In this study, we investigated this long-standing question by analyzing the rotational dynamics of cargos at microtubule intersections in unprecedented detail. By using a novel single-particle rotational imaging method, we simultaneously resolved the rotational and translational motion of endosomes in living cells, and determined the correlation of their dynamics with underlying microtubule structures. While it was previously known that cargos pause and switch directions at microtubule intersections, this study provides the first evidence demonstrating rotational dynamics of intracellular cargos at microtubule intersections and elucidating the underlying driving forces behind such movements.