Single-molecule FRET reveals multiscale chromatin dynamics modulated by HP1α
| Autor: | Iuliia Boichenko, Olga Doroshenko, Hayk Vardanyan, Mykola Dimura, Sinan Kilic, Claus A. M. Seidel, Gaurav Arya, Suren Felekyan, Beat Fierz, Louise C. Bryan |
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| Předmět: |
0301 basic medicine
Heterochromatin Chromosomal Proteins Non-Histone Science Stacking Molecular Conformation General Physics and Astronomy Methylation General Biochemistry Genetics and Molecular Biology Article Histones 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Fluorescence Resonance Energy Transfer Nucleosome Animals lcsh:Science Regulation of gene expression Multidisciplinary Chemistry General Chemistry Single-molecule FRET DNA Chromatin Nucleosomes Kinetics 030104 developmental biology Förster resonance energy transfer Gene Expression Regulation Microscopy Fluorescence Chromobox Protein Homolog 5 Biophysics Nucleic Acid Conformation lcsh:Q 030217 neurology & neurosurgery Protein Binding |
| Zdroj: | Nature Communications Nature Communications, Vol 9, Iss 1, Pp 1-14 (2018) |
| Popis: | 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. Chromatin fibers undergo continuous structural rearrangements but their dynamic architecture is poorly understood. Here, the authors use single-molecule FRET to determine the structural states and interconversion kinetics of chromatin fibers, monitoring their effector protein-dependent dynamic motions. |
| Databáze: | OpenAIRE |
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