Centromere assembly requires the direct recognition of CENP-A nucleosomes by CENP-N

Nat Cell Biol. 2009 Jul;11(7):896-902. doi: 10.1038/ncb1899. Epub 2009 Jun 21.

Abstract

Centromeres are specialized chromosomal domains that direct kinetochore assembly during mitosis. CENP-A (centromere protein A), a histone H3-variant present exclusively in centromeric nucleosomes, is thought to function as an epigenetic mark that specifies centromere identity. Here we identify the essential centromere protein CENP-N as the first protein to selectively bind CENP-A nucleosomes but not H3 nucleosomes. CENP-N bound CENP-A nucleosomes in a DNA sequence-independent manner, but did not bind soluble CENP-A-H4 tetramers. Mutations in CENP-N that reduced its affinity for CENP-A nucleosomes caused defects in CENP-N localization and had dominant effects on the recruitment of CENP-H, CENP-I and CENP-K to centromeres. Depletion of CENP-N using siRNA (short interfering RNA) led to similar centromere assembly defects and resulted in reduced assembly of nascent CENP-A into centromeric chromatin. These data suggest that CENP-N interprets the information encoded within CENP-A nucleosomes and recruits other proteins to centromeric chromatin that are required for centromere function and propagation.

Publication types

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

MeSH terms

  • Autoantigens / metabolism*
  • Cell Line
  • Centromere / genetics
  • Centromere / metabolism
  • Centromere Protein A
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Electrophoretic Mobility Shift Assay
  • HeLa Cells
  • Humans
  • Microscopy, Fluorescence
  • Nucleosomes / metabolism*
  • Protein Binding
  • RNA, Small Interfering

Substances

  • Autoantigens
  • CENPA protein, human
  • Centromere Protein A
  • Chromosomal Proteins, Non-Histone
  • Nucleosomes
  • RNA, Small Interfering