High-throughput AFM analysis reveals unwrapping pathways of H3 and CENP-A nucleosomes

Autor: Konrad, Sebastian F., Vanderlinden, Willem, Frederickx, Wout, Brouns, Tine, Menze, Björn H., De Feyter, Steven, Lipfert, Jan, Sub Molecular Biophysics, Soft Condensed Matter and Biophysics
Přispěvatelé: University of Zurich, Vanderlinden, Willem, Lipfert, Jan, Sub Molecular Biophysics, Soft Condensed Matter and Biophysics
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Nanoscale, 13(10), 5435. Royal Society of Chemistry
ISSN: 2040-3364
DOI: 10.1101/2020.04.09.034090
Popis: Nucleosomes, the fundamental units of chromatin, regulate readout and expression of eukaryotic genomes. Single-molecule experiments have revealed force-induced nucleosome accessibility, but a high-resolution unwrapping landscape in the absence of external forces is currently lacking. Here, we introduce a high-throughput pipeline for the analysis of nucleosome conformations based on atomic force microscopy and automated, multi-parameter image analysis. Our data set of ∼10 000 nucleosomes reveals multiple unwrapping states corresponding to steps of 5 bp DNA. For canonical H3 nucleosomes, we observe that dissociation from one side impedes unwrapping from the other side, but in contrast to force-induced unwrapping, we find only a weak sequence-dependent asymmetry. Notably, centromeric CENP-A nucleosomes do not unwrap anti-cooperatively, in stark contrast to H3 nucleosomes. Finally, our results reconcile previous conflicting findings about the differences in height between H3 and CENP-A nucleosomes. We expect our approach to enable critical insights into epigenetic regulation of nucleosome structure and stability and to facilitate future high-throughput AFM studies that involve heterogeneous nucleoprotein complexes. ispartof: NANOSCALE vol:13 issue:10 pages:5435-5447 ispartof: location:England status: published
Databáze: OpenAIRE