By binding to and “walking along” microtubules of the mitotic spindle, Kinesin-14 motor proteins coordinate accurate chromosome segregation during mitosis (cell division). Scientists had long believed that human Kinesin-14 HSET is “processive,” meaning it takes multiple steps along a microtubule without dissociating (i.e., disengaging from their microtubule track).

Now, Albert Einstein College of Medicine researchers led by Arne Gennerich, Ph.D., have conclusively shown that mitotic Kinesin-14 motors are actually non-processive: rather than move continuously along microtubules, they instead bind to microtubules, perform a single power stroke to either push or pull on the microtubule, and then dissociate. And contrary to earlier studies suggesting that Kinesin-14 motor proteins work antagonistically in teams, the study reveals that the proteins are evolutionarily designed to cooperate with, rather than antagonize, each other. Since Kinesin-14 motors are crucial for cell division, the findings could lead to therapies that treat cancer by preventing cancer cells from dividing.

The research results were published online on August 3 in Nature Communications. Dr. Gennerich is professor of biochemistry at Einstein.