Single-molecule FRET reveals multiscale chromatin dynamics modulated by HP1α.

Published

Journal Article

The dynamic architecture of chromatin fibers, a key determinant of genome regulation, is poorly understood. Here, we employ multimodal single-molecule Förster resonance energy transfer studies to reveal structural states and their interconversion kinetics in chromatin fibers. We show that nucleosomes engage in short-lived (micro- to milliseconds) stacking interactions with one of their neighbors. This results in discrete tetranucleosome units with distinct interaction registers that interconvert within hundreds of milliseconds. Additionally, we find that dynamic chromatin architecture is modulated by the multivalent architectural protein heterochromatin protein 1α (HP1α), which engages methylated histone tails and thereby transiently stabilizes stacked nucleosomes. This compacted state nevertheless remains dynamic, exhibiting fluctuations on the timescale of HP1α residence times. Overall, this study reveals that exposure of internal DNA sites and nucleosome surfaces in chromatin fibers is governed by an intrinsic dynamic hierarchy from micro- to milliseconds, allowing the gene regulation machinery to access compact chromatin.

Full Text

Duke Authors

Cited Authors

  • Kilic, S; Felekyan, S; Doroshenko, O; Boichenko, I; Dimura, M; Vardanyan, H; Bryan, LC; Arya, G; Seidel, CAM; Fierz, B

Published Date

  • January 16, 2018

Published In

Volume / Issue

  • 9 / 1

Start / End Page

  • 235 -

PubMed ID

  • 29339721

Pubmed Central ID

  • 29339721

Electronic International Standard Serial Number (EISSN)

  • 2041-1723

International Standard Serial Number (ISSN)

  • 2041-1723

Digital Object Identifier (DOI)

  • 10.1038/s41467-017-02619-5

Language

  • eng