Format

Send to

Choose Destination
Nat Commun. 2016 Apr 19;7:11310. doi: 10.1038/ncomms11310.

Dynamic and flexible H3K9me3 bridging via HP1β dimerization establishes a plastic state of condensed chromatin.

Author information

1
Laboratory of Chromatin Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Am Fassberg 11, 37077, Germany.
2
Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, Göttingen, Am Fassberg 11, 37077, Germany.
3
Applied Synthetic Biology, Institute for Microbiology and Genetics, Georg-August University Göttingen, 37077 Göttingen, Germany.
4
Department of Medical Genetics, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3.
5
Department of Epigenetics, Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108 Freiburg, Germany.
6
Biaffin GmbH &Co KG, Heinrich-Plett Strasse 40, 34132 Kassel, Germany.
7
Biomolecular Spectroscopy and Single-Molecule Detection, Max Planck Institute for Biophysical Chemistry, Göttingen, Am Fassberg 11, 37077, Germany.
8
Bioanalytics, Institute for Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany.
9
Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany.
10
Department of Biophysical Chemistry, Technische Universität Braunschweig, Hans-Sommerstr. 10, 38106 Braunschweig, Germany.
11
Department of Molecular Mechanisms of Disease, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.

Abstract

Histone H3 trimethylation of lysine 9 (H3K9me3) and proteins of the heterochromatin protein 1 (HP1) family are hallmarks of heterochromatin, a state of compacted DNA essential for genome stability and long-term transcriptional silencing. The mechanisms by which H3K9me3 and HP1 contribute to chromatin condensation have been speculative and controversial. Here we demonstrate that human HP1β is a prototypic HP1 protein exemplifying most basal chromatin binding and effects. These are caused by dimeric and dynamic interaction with highly enriched H3K9me3 and are modulated by various electrostatic interfaces. HP1β bridges condensed chromatin, which we postulate stabilizes the compacted state. In agreement, HP1β genome-wide localization follows H3K9me3-enrichment and artificial bridging of chromatin fibres is sufficient for maintaining cellular heterochromatic conformation. Overall, our findings define a fundamental mechanism for chromatin higher order structural changes caused by HP1 proteins, which might contribute to the plastic nature of condensed chromatin.

PMID:
27090491
PMCID:
PMC4838890
DOI:
10.1038/ncomms11310
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Nature Publishing Group Icon for PubMed Central
Loading ...
Support Center