Kinesin-12 Kif15 targets kinetochore fibers through an intrinsic two-step mechanism. Academic Article uri icon


  • Proteins that recognize and act on specific subsets of microtubules (MTs) enable the varied functions of the MT cytoskeleton. We recently discovered that Kif15 localizes exclusively to kinetochore fibers (K-fibers) or bundles of kinetochore-MTs within the mitotic spindle. It is currently speculated that the MT-associated protein TPX2 loads Kif15 onto spindle MTs, but this model has not been rigorously tested. Here, we show that Kif15 accumulates on MT bundles as a consequence of two inherent biochemical properties. First, Kif15 is self-repressed by its C terminus. Second, Kif15 harbors a nonmotor MT-binding site, enabling dimeric Kif15 to crosslink and slide MTs. Two-MT binding activates Kif15, resulting in its accumulation on and motility within MT bundles but not on individual MTs. We propose that Kif15 targets K-fibers via an intrinsic two-step mechanism involving molecular unfolding and two-MT binding. This work challenges the current model of Kif15 regulation and provides the first account of a kinesin that specifically recognizes a higher-order MT array.

published proceedings

  • Curr Biol

author list (cited authors)

  • Sturgill, E. G., Das, D. K., Takizawa, Y., Shin, Y., Collier, S. E., Ohi, M. D., ... Ohi, R.

citation count

  • 42

complete list of authors

  • Sturgill, Emma G||Das, Dibyendu Kumar||Takizawa, Yoshimasa||Shin, Yongdae||Collier, Scott E||Ohi, Melanie D||Hwang, Wonmuk||Lang, Matthew J||Ohi, Ryoma

publication date

  • October 2014