Phosphorylation of the CENP-A amino-terminus in mitotic centromeric chromatin is required for kinetochore function

Proc Natl Acad Sci U S A. 2013 May 21;110(21):8579-84. doi: 10.1073/pnas.1302955110. Epub 2013 May 8.

Abstract

The role of the mitotic phosphorylation of the amino (NH2) terminus of Centromere Protein A (CENP-A), the histone variant epigenetic centromeric marker, remains elusive. Here, we show that the NH2 terminus of human CENP-A is essential for mitotic progression and that localization of CENP-C, another key centromeric protein, requires only phosphorylation of the CENP-A NH2 terminus, and is independent of the CENP-A NH2 terminus length and amino acid sequence. Mitotic CENP-A nucleosomal complexes contain CENP-C and phosphobinding 14-3-3 proteins. In contrast, mitotic nucleosomal complexes carrying nonphosphorylatable CENP-A-S7A contained only low levels of CENP-C and no detectable 14-3-3 proteins. Direct interactions between the phosphorylated form of CENP-A and 14-3-3 proteins as well as between 14-3-3 proteins and CENP-C were demonstrated. Taken together, our results reveal that 14-3-3 proteins could act as specific mitotic "bridges," linking phosphorylated CENP-A and CENP-C, which are necessary for the platform function of CENP-A centromeric chromatin in the assembly and maintenance of active kinetochores.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 14-3-3 Proteins / genetics
  • 14-3-3 Proteins / metabolism
  • Amino Acid Substitution
  • Autoantigens / genetics
  • Autoantigens / metabolism*
  • Centromere Protein A
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • HeLa Cells
  • Humans
  • Kinetochores / metabolism*
  • Mitosis / physiology*
  • Mutation, Missense
  • Nucleosomes / genetics
  • Nucleosomes / metabolism*
  • Phosphorylation
  • Protein Structure, Tertiary

Substances

  • 14-3-3 Proteins
  • Autoantigens
  • CENPA protein, human
  • Centromere Protein A
  • Chromosomal Proteins, Non-Histone
  • Nucleosomes
  • centromere protein C