Collective Behavior of Antagonistically Acting Kinesin-1 Motors

In many subcellular force-generating systems, groups of motor proteins act antagonistically. Here, we present an experimental study of the tug of war between superprocessive kinesin-1 motors acting on antiparallel microtubule doublets in vitro. We found distinct modes of slow and fast movements, as well as sharp transitions between these modes and regions of coexistence. We compare our experimental results to a quantitative theory based on the physical properties of individual motors. Our results show that mechanical interactions between motors can collectively generate coexisting transport regimes with distinct velocities.