The findings suggest that microtubules are altered by kinesin in such a way that they attract more motors. ATP hydrolysis by kinesin was required for cooperativity, but how the energy is used is not known. The group is currently investigating how kinesin binding affects the movement of positive ions that surround the negatively charged microtubules. These changes may in turn alter kinesin motility.
The preference of kinesin for already-bound microtubules in vivo may establish a set of microtubules that is dedicated to vesicle trafficking. This idea fits well with previous findings that axonal microtubules carry either many vesicles or very few.