Dual recognition of CENP-A nucleosomes is required for centromere assembly

J Cell Biol. 2010 Jun 28;189(7):1143-55. doi: 10.1083/jcb.201001013. Epub 2010 Jun 21.

Abstract

Centromeres contain specialized nucleosomes in which histone H3 is replaced by the histone variant centromere protein A (CENP-A). CENP-A nucleosomes are thought to act as an epigenetic mark that specifies centromere identity. We previously identified CENP-N as a CENP-A nucleosome-specific binding protein. Here, we show that CENP-C also binds directly and specifically to CENP-A nucleosomes. Nucleosome binding by CENP-C required the extreme C terminus of CENP-A and did not compete with CENP-N binding, which suggests that CENP-C and CENP-N recognize distinct structural elements of CENP-A nucleosomes. A mutation that disrupted CENP-C binding to CENP-A nucleosomes in vitro caused defects in CENP-C targeting to centromeres. Moreover, depletion of CENP-C with siRNA resulted in the mislocalization of all other nonhistone CENPs examined, including CENP-K, CENP-H, CENP-I, and CENP-T, and led to a partial reduction in centromeric CENP-A. We propose that CENP-C binds directly to CENP-A chromatin and, together with CENP-N, provides the foundation upon which other centromere and kinetochore proteins are assembled.

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*
  • Centromere / metabolism*
  • Centromere Protein A
  • Chromatin
  • Chromosomal Proteins, Non-Histone / deficiency
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Humans
  • Mutation
  • Nucleosomes / metabolism*
  • Protein Binding
  • RNA, Small Interfering / pharmacology

Substances

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