Xkid, a chromokinesin required for chromosome alignment on the metaphase plate

Cell. 2000 Aug 18;102(4):425-35. doi: 10.1016/s0092-8674(00)00048-9.


Metaphase chromosome alignment is a key step of animal cell mitosis. The molecular mechanism leading to this equatorial positioning is still not fully understood. Forces exerted at kinetochores and on chromosome arms drive chromosome movements that culminate in their alignment on the metaphase plate. In this paper, we show that Xkid, a kinesin-like protein localized on chromosome arms, plays an essential role in metaphase chromosome alignment and in its maintenance. We propose that Xkid is responsible for the polar ejection forces acting on chromosome arms. Our results show that these forces are essential to ensure that kinetochores and chromosome arms align on a narrow equatorial plate during metaphase, a prerequisite for proper chromosome segregation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Chromosomes / physiology*
  • Cloning, Molecular
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Kinesin / genetics
  • Kinesin / physiology*
  • Metaphase / genetics*
  • Microscopy, Video
  • Microtubule Proteins / metabolism
  • Molecular Sequence Data
  • Xenopus
  • Xenopus Proteins*


  • DNA-Binding Proteins
  • KIFF22 protein, Xenopus
  • Microtubule Proteins
  • Xenopus Proteins
  • Kinesin