Nucleosome organization and chromatin dynamics in telomeres

Biomol Concepts. 2015 Mar;6(1):67-75. doi: 10.1515/bmc-2014-0035.

Abstract

Telomeres are DNA-protein complexes located at the ends of linear eukaryotic chromosomes, and are essential for chromosome stability and maintenance. In most organisms, telomeres consist of tandemly repeated sequences of guanine-clusters. In higher eukaryotes, most of the telomeric repeat regions are tightly packaged into nucleosomes, even though telomeric repeats act as nucleosome-disfavoring sequences. Although telomeres were considered to be condensed heterochromatin structures, recent studies revealed that the chromatin structures in telomeres are actually dynamic. The dynamic properties of telomeric chromatin are considered to be important for the structural changes between the euchromatic and heterochromatic states during the cell cycle and in cellular differentiation. We propose that the nucleosome-disfavoring property of telomeric repeats is a crucial determinant for the lability of telomeric nucleosomes, and provides a platform for chromatin dynamics in telomeres. Furthermore, we discuss the influences of telomeric components on the nucleosome organization and chromatin dynamics in telomeres.

Publication types

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

MeSH terms

  • Chromatin / metabolism*
  • DNA / chemistry
  • Histones / metabolism*
  • Humans
  • Nucleosomes / chemistry*
  • Nucleosomes / metabolism*
  • Protein Isoforms / metabolism
  • Protein Processing, Post-Translational
  • Telomere / metabolism*
  • Telomeric Repeat Binding Protein 1 / metabolism
  • Telomeric Repeat Binding Protein 2 / metabolism
  • Yeasts

Substances

  • Chromatin
  • Histones
  • Nucleosomes
  • Protein Isoforms
  • TERF2 protein, human
  • Telomeric Repeat Binding Protein 1
  • Telomeric Repeat Binding Protein 2
  • DNA