The microtubule-binding protein Cep170 promotes the targeting of the kinesin-13 depolymerase Kif2b to the mitotic spindle

Mol Biol Cell. 2012 Dec;23(24):4786-95. doi: 10.1091/mbc.E12-03-0214. Epub 2012 Oct 19.

Abstract

Microtubule dynamics are essential throughout mitosis to ensure correct chromosome segregation. Microtubule depolymerization is controlled in part by microtubule depolymerases, including the kinesin-13 family of proteins. In humans, there are three closely related kinesin-13 isoforms (Kif2a, Kif2b, and Kif2c/MCAK), which are highly conserved in their primary sequences but display distinct localization and nonoverlapping functions. Here we demonstrate that the N-terminus is a primary determinant of kinesin-13 localization. However, we also find that differences in the C-terminus alter the properties of kinesin-13, in part by facilitating unique protein-protein interactions. We identify the spindle-localized proteins Cep170 and Cep170R (KIAA0284) as specifically associating with Kif2b. Cep170 binds to microtubules in vitro and provides Kif2b with a second microtubule-binding site to target it to the spindle. Thus the intrinsic properties of kinesin-13s and extrinsic factors such as their associated proteins result in the diversity and specificity within the kinesin-13 depolymerase family.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites / genetics
  • Blotting, Western
  • HeLa Cells
  • Humans
  • Kinesins / chemistry
  • Kinesins / genetics
  • Kinesins / metabolism*
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Microscopy, Fluorescence
  • Microtubule-Associated Proteins
  • Microtubules / metabolism*
  • Molecular Sequence Data
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Protein Binding
  • RNA Interference
  • Sequence Homology, Amino Acid
  • Spindle Apparatus / metabolism*

Substances

  • Cep170 protein, human
  • Luminescent Proteins
  • Microtubule-Associated Proteins
  • Phosphoproteins
  • KIF2B protein, human
  • Kinesins