Specification of kinetochore-forming chromatin by the histone H3 variant CENP-A

J Cell Sci. 2001 Oct;114(Pt 19):3529-42. doi: 10.1242/jcs.114.19.3529.

Abstract

The mechanisms that specify precisely where mammalian kinetochores form within arrays of centromeric heterochromatin remain largely unknown. Localization of CENP-A exclusively beneath kinetochore plates suggests that this distinctive histone might direct kinetochore formation by altering the structure of heterochromatin within a sub-region of the centromere. To test this hypothesis, we experimentally mistargeted CENP-A to non-centromeric regions of chromatin and determined whether other centromere-kinetochore components were recruited. CENP-A-containing non-centromeric chromatin assembles a subset of centromere-kinetochore components, including CENP-C, hSMC1, and HZwint-1 by a mechanism that requires the unique CENP-A N-terminal tail. The sequence-specific DNA-binding protein CENP-B and the microtubule-associated proteins CENP-E and HZW10 were not recruited, and neocentromeric activity was not detected. Experimental mistargeting of CENP-A to inactive centromeres or to acentric double-minute chromosomes was also not sufficient to assemble complete kinetochore activity. The recruitment of centromere-kinetochore proteins to chromatin appears to be a unique function of CENP-A, as the mistargeting of other components was not sufficient for assembly of the same complex. Our results indicate at least two distinct steps in kinetochore assembly: (1) precise targeting of CENP-A, which is sufficient to assemble components of a centromere-prekinetochore scaffold; and (2) targeting of kinetochore microtubule-associated proteins by an additional mechanism present only at active centromeres.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Autoantigens*
  • CHO Cells
  • Centromere Protein A
  • Centromere Protein B
  • Chromatin / metabolism*
  • Chromosomal Proteins, Non-Histone / chemistry
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Cricetinae
  • DNA-Binding Proteins*
  • Gene Expression
  • HeLa Cells
  • Histones
  • Humans
  • Kinetochores / metabolism*
  • Microtubule-Associated Proteins / metabolism
  • Mitosis / physiology
  • Molecular Sequence Data
  • Protein Structure, Tertiary
  • Transfection

Substances

  • Autoantigens
  • CENPA protein, human
  • CENPB protein, human
  • Centromere Protein A
  • Centromere Protein B
  • Chromatin
  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • Histones
  • Microtubule-Associated Proteins
  • centromere protein C