A minus-end motor sees the plus side

New results from Brina Sheeman, David Pellman (Harvard Medical School, Boston, MA), and colleagues indicate that dynein, a minus end–directed microtubule motor, hops a ride to the membrane on plus ends. The results are inconsistent with current models of dynein activation and localization.

As a minus end–directed motor, dynein walks along astral microtubules toward the spindle pole, and thus could reel in the spindle during anaphase. The favored model for this movement predicts that dynein first binds to the bud cortex, where it captures passing microtubules. From there it could pull the spindle toward the bud. However, at least in budding yeast, significant amounts of dynein have not been found at the cortex. Nonetheless, according to Pellman, “the model is so intuitively appealing that the supposition...