Unstable microtubule capture at kinetochores depleted of the centromere-associated protein CENP-F

EMBO J. 2005 Nov 16;24(22):3927-39. doi: 10.1038/sj.emboj.7600848. Epub 2005 Oct 27.


Centromere protein F (CENP-F) (or mitosin) accumulates to become an abundant nuclear protein in G2, assembles at kinetochores in late G2, remains kinetochore-bound until anaphase, and is degraded at the end of mitosis. Here we show that the absence of nuclear CENP-F does not affect cell cycle progression in S and G2. In a subset of CENP-F depleted cells, kinetochore assembly fails completely, thereby provoking massive chromosome mis-segregation. In contrast, the majority of CENP-F depleted cells exhibit a strong mitotic delay with reduced tension between kinetochores of aligned, bi-oriented sister chromatids and decreased stability of kinetochore microtubules. These latter kinetochores generate mitotic checkpoint signaling when unattached, recruiting maximum levels of Mad2. Use of YFP-marked Mad1 reveals that throughout the mitotic delay some aligned, CENP-F depleted kinetochores continuously recruit Mad1. Others rebind YFP-Mad1 intermittently so as to produce 'twinkling', demonstrating cycles of mitotic checkpoint reactivation and silencing and a crucial role for CENP-F in efficient assembly of a stable microtubule-kinetochore interface.

Publication types

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

MeSH terms

  • Animals
  • Cell Cycle / physiology*
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cell Nucleus / metabolism
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Chromosomes / metabolism
  • Gene Silencing
  • HeLa Cells
  • Humans
  • Kinetochores / metabolism*
  • Microfilament Proteins
  • Microtubules / metabolism*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Protein Binding
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction / physiology


  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • Microfilament Proteins
  • Nuclear Proteins
  • RNA, Small Interfering
  • Recombinant Fusion Proteins
  • centromere protein F