DNA looping mediates nucleosome transfer

Nat Commun. 2016 Nov 3;7:13337. doi: 10.1038/ncomms13337.

Abstract

Proper cell function requires preservation of the spatial organization of chromatin modifications. Maintenance of this epigenetic landscape necessitates the transfer of parental nucleosomes to newly replicated DNA, a process that is stringently regulated and intrinsically linked to replication fork dynamics. This creates a formidable setting from which to isolate the central mechanism of transfer. Here we utilized a minimal experimental system to track the fate of a single nucleosome following its displacement, and examined whether DNA mechanics itself, in the absence of any chaperones or assembly factors, may serve as a platform for the transfer process. We found that the nucleosome is passively transferred to available dsDNA as predicted by a simple physical model of DNA loop formation. These results demonstrate a fundamental role for DNA mechanics in mediating nucleosome transfer and preserving epigenetic integrity during replication.

Publication types

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

MeSH terms

  • DNA / genetics*
  • DNA / metabolism
  • DNA Replication / physiology*
  • Epigenesis, Genetic / physiology*
  • HeLa Cells
  • Histone Chaperones / physiology
  • Humans
  • Nucleosomes / genetics
  • Nucleosomes / metabolism*

Substances

  • Histone Chaperones
  • Nucleosomes
  • DNA