Heterogeneous architecture of vertebrate kinetochores revealed by three-dimensional superresolution fluorescence microscopy

Mol Biol Cell. 2016 Nov 7;27(22):3395-3404. doi: 10.1091/mbc.E16-02-0130. Epub 2016 May 11.


The kinetochore is often depicted as having a disk-like architecture in which the outer layer of proteins, which engage microtubules and control checkpoint signaling, are built on a static inner layer directly linked to CENP-A chromatin. Here, applying three-dimensional (3D) structural illumination microscopy (SIM) and stochastic optical reconstruction microscopy (STORM) to Xenopus egg extracts and tissue culture cells, we report various distribution patterns of inner and outer kinetochore proteins. In egg extracts, a configuration in which outer kinetochore proteins surround the periphery of CENP-A chromatin is common, forming an ∼200-nm ring-like organization that may engage a bundle of microtubule ends. Similar rings are observed in Xenopus tissue culture cells at a lower frequency but are enriched in conditions in which the spindle is disorganized. Although rings are rare in human cells, the distribution of both inner and outer kinetochore proteins elongates in the absence of microtubule attachment in a manner dependent on Aurora B. We propose a model in which the 3D organization of both the outer and inner kinetochore regions respond to the progression from lateral to end-on microtubule attachments by coalescing into a tight disk from less uniform distributions early in prometaphase.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Aurora Kinase B / metabolism
  • Autoantigens / metabolism
  • Cell Cycle Proteins / metabolism
  • Centromere Protein A
  • Chromatin / metabolism
  • Chromosomal Proteins, Non-Histone / metabolism
  • Humans
  • Kinetochores / physiology*
  • Kinetochores / ultrastructure*
  • Microscopy, Fluorescence
  • Microtubule-Associated Proteins / metabolism
  • Microtubules
  • Spindle Apparatus / metabolism
  • Xenopus laevis


  • Autoantigens
  • CENPA protein, human
  • Cell Cycle Proteins
  • Centromere Protein A
  • Chromatin
  • Chromosomal Proteins, Non-Histone
  • Microtubule-Associated Proteins
  • Aurora Kinase B