scholarly journals Interaction between Nonhistone Protein HMGB1 and Linker Histone H1 Facilitates the Formation of Structurally Ordered DNA-Protein Complexes

2012 ◽  
Vol 27 ◽  
pp. 393-398 ◽  
Author(s):  
Alexander Polyanichko ◽  
Elena Chikhirzhina
Keyword(s):  
Protein Complexes ◽  
Histone H1 ◽  
Linker Histone ◽  
Chromosomal Protein ◽  
Dna Complexes ◽  
Force Microscopy ◽  
Linker Histone H1 ◽  
Nonhistone Protein ◽  
Atomic Force ◽  
Nonhistone Chromosomal Protein

The structural organization of the DNA complexes with nonhistone chromosomal protein and linker histone H1 was studied using circular dichroism spectroscopy (CD) and atomic force microscopy (AFM). It has been shown that due to the interaction between HMGB1 and H1 highly ordered DNA-protein complexes emerge in the solution. Their spectral properties are found to be similar to those of DNA/HMGB1-(AB) complexes, reported earlier. AFM images reveal the formation of fibril-like structures in the solution. We suggest that the electrostatic screening of the HMGB1 C-terminal domain by histone H1 facilitates stronger interaction of the HMGB1/H1 with DNA and the formation of the ordered supramolecular DNA-protein complexes.

scholarly journals Conformation of Reconstituted Mononucleosomes and Effect of Linker Histone H1 Binding Studied by Scanning Force Microscopy

2003 ◽  
Vol 85 (6) ◽  
pp. 4012-4022 ◽  
Author(s):  
Jochen Felix Kepert ◽  
Katalin Fejes Tóth ◽  
Maïwen Caudron ◽  
Norbert Mücke ◽  
Jörg Langowski ◽  
...  
Keyword(s):  
Scanning Force Microscopy ◽  
Histone H1 ◽  
Linker Histone ◽  
Force Microscopy ◽  
Linker Histone H1 ◽  
Scanning Force

scholarly journals Structural organization of DNA–protein complexes of chromatin studied by vibrational and electronic circular dichroism

2010 ◽  
Vol 24 (3-4) ◽  
pp. 239-244 ◽  
Author(s):  
Alexander Polyanichko ◽  
Helmut Wieser
Keyword(s):  
Circular Dichroism ◽  
Protein Complexes ◽  
High Mobility ◽  
Histone H1 ◽  
Cd Spectroscopy ◽  
Linker Histone ◽  
High Mobility Group ◽  
Ir Absorption ◽  
Linker Histone H1 ◽  
Circular Dichroïsm

Structure and functioning of chromatin is determined by interactions of DNA with numerous nuclear proteins. The most abundant and yet not completely understood non-histone chromosomal proteins are those belonging to a High Mobility Group (HMG) namely HMGB1. The interplay of this protein on DNA with linker histone H1 and other proteins determines both structure and functioning of the chromatin. A combination of UV and IR absorption and circular dichroism (CD) spectroscopy was applied to investigate the structure and formation of large supramolecular DNA–protein complexes. This combination of techniques was used to overcome limitations of UV-CD (ECD) spectroscopy due to considerable light scattering in such solutions. Based on the analysis of FTIR and UV circular dichroism spectra and AFM imaging the interaction of DNA with high-mobility group non-histone chromatin protein HMGB1 and linker histone H1 was studied.

scholarly journals Single-stranded nucleic acid sensing and coacervation by linker histone H1

2021 ◽  
Author(s):  
Rachel Leicher ◽  
Adewola Osunsade ◽  
Andrew Latham ◽  
Gabriella N.L. Chua ◽  
John W. Watters ◽  
...  
Keyword(s):  
Single Molecule ◽  
Histone H1 ◽  
Linker Histone ◽  
Force Microscopy ◽  
Linker Histone H1 ◽  
Eukaryotic Chromatin ◽  
Transient Interactions ◽  
Nuclear Regions ◽  
New Perspective ◽  
Dynamics Simulations

The linker histone H1 is the most abundant group of eukaryotic chromatin-binding proteins. The mechanism underlying the diverse physiological functions of H1 remains unclear. Here we used single-molecule fluorescence and force microscopy to observe the behavior of H1 on DNA under different tensions. Unexpectedly, we found that H1 coalesces around nascent ssDNA. Molecular dynamics simulations revealed that multivalent and transient interactions between H1 and ssDNA mediate their phase separation. We further showed that longer and unpaired nucleic acids result in more viscous, gel-like H1 droplets. Finally, we imaged H1 puncta in cells under normal and stressed conditions and observed that RPA and H1 occupy separate nuclear regions. Overall, our results provide a new perspective to understanding the role of H1 in genome organization and maintenance.

Single Molecular Observation of DNA and DNA Complexes by Atomic Force Microscopy

2012 ◽  
Vol 13 (14) ◽  
pp. 2589-2598 ◽  
Author(s):  
Takuya Matsumoto ◽  
Eriko Mikamo-Satoh ◽  
Akihiko Takagi ◽  
Tomoji Kawai
Keyword(s):  
Atomic Force Microscopy ◽  
Dna Complexes ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Site-specific ubiquitylation acts as a regulator of linker histone H1

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eva Höllmüller ◽  
Simon Geigges ◽  
Marie L. Niedermeier ◽  
Kai-Michael Kammer ◽  
Simon M. Kienle ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Histone H1 ◽  
Linker Histone ◽  
Active Chromatin ◽  
Site Specific ◽  
Linker Histone H1 ◽  
Fundamental Process ◽  
Core Histones ◽  
Wide Scale

AbstractDecoding the role of histone posttranslational modifications (PTMs) is key to understand the fundamental process of epigenetic regulation. This is well studied for PTMs of core histones but not for linker histone H1 in general and its ubiquitylation in particular due to a lack of proper tools. Here, we report on the chemical synthesis of site-specifically mono-ubiquitylated H1.2 and identify its ubiquitin-dependent interactome on a proteome-wide scale. We show that site-specific ubiquitylation of H1 at position K64 modulates interactions with deubiquitylating enzymes and the deacetylase SIRT1. Moreover, it affects H1-dependent chromatosome assembly and phase separation resulting in a more open chromatosome conformation generally associated with a transcriptionally active chromatin state. In summary, we propose that site-specific ubiquitylation plays a general regulatory role for linker histone H1.

scholarly journals The histone variant H2A.W and linker histone H1 co-regulate heterochromatin accessibility and DNA methylation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pierre Bourguet ◽  
Colette L. Picard ◽  
Ramesh Yelagandula ◽  
Thierry Pélissier ◽  
Zdravko J. Lorković ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Histone H1 ◽  
Epigenetic Modifications ◽  
Flowering Plants ◽  
Linker Histone ◽  
Histone Variant ◽  
Null Mutant ◽  
Chromatin Compaction ◽  
Linker Histone H1

AbstractIn flowering plants, heterochromatin is demarcated by the histone variant H2A.W, elevated levels of the linker histone H1, and specific epigenetic modifications, such as high levels of DNA methylation at both CG and non-CG sites. How H2A.W regulates heterochromatin organization and interacts with other heterochromatic features is unclear. Here, we create a h2a.w null mutant via CRISPR-Cas9, h2a.w-2, to analyze the in vivo function of H2A.W. We find that H2A.W antagonizes deposition of H1 at heterochromatin and that non-CG methylation and accessibility are moderately decreased in h2a.w-2 heterochromatin. Compared to H1 loss alone, combined loss of H1 and H2A.W greatly increases accessibility and facilitates non-CG DNA methylation in heterochromatin, suggesting co-regulation of heterochromatic features by H2A.W and H1. Our results suggest that H2A.W helps maintain optimal heterochromatin accessibility and DNA methylation by promoting chromatin compaction together with H1, while also inhibiting excessive H1 incorporation.

scholarly journals Dialysis Purification of Integrase-DNA Complexes Provides High-Resolution Atomic Force Microscopy Images: Dimeric Recombinant HIV-1 Integrase Binding and Specific Looping on DNA

PLoS ONE ◽  
2013 ◽  
Vol 8 (1) ◽  
pp. e53572 ◽  
Author(s):  
Tatsuaki Tsuruyama ◽  
Tonau Nakai ◽  
Rei Ohmori ◽  
Munetaka Ozeki ◽  
Keiji Tamaki ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
High Resolution ◽  
Dna Complexes ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Images ◽  
Hiv 1

scholarly journals Label-Free Mass Spectrometry-Based Quantification of Linker Histone H1 Variants in Clinical Samples

2020 ◽  
Vol 21 (19) ◽  
pp. 7330
Author(s):  
Roberta Noberini ◽  
Cristina Morales Torres ◽  
Evelyn Oliva Savoia ◽  
Stefania Brandini ◽  
Maria Giovanna Jodice ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Histone H1 ◽  
Histone Variants ◽  
Linker Histone ◽  
Clinical Samples ◽  
Label Free ◽  
Complex Samples ◽  
Linker Histone H1 ◽  
Ideal Tool ◽  
Free Quantification

Epigenetic aberrations have been recognized as important contributors to cancer onset and development, and increasing evidence suggests that linker histone H1 variants may serve as biomarkers useful for patient stratification, as well as play an important role as drivers in cancer. Although traditionally histone H1 levels have been studied using antibody-based methods and RNA expression, these approaches suffer from limitations. Mass spectrometry (MS)-based proteomics represents the ideal tool to accurately quantify relative changes in protein abundance within complex samples. In this study, we used a label-free quantification approach to simultaneously analyze all somatic histone H1 variants in clinical samples and verified its applicability to laser micro-dissected tissue areas containing as low as 1000 cells. We then applied it to breast cancer patient samples, identifying differences in linker histone variants patters in primary triple-negative breast tumors with and without relapse after chemotherapy. This study highlights how label-free quantitation by MS is a valuable option to accurately quantitate histone H1 levels in different types of clinical samples, including very low-abundance patient tissues.

Quantitative Assessment of Transition Proteins 1, 2 Spermatid-Specific Linker Histone H1-Like Protein Transcripts in Spermatozoa from Normozoospermic and Asthenozoospermic Men

2007 ◽  
Vol 53 (4) ◽  
pp. 199-205 ◽  
Author(s):  
Piotr Jedrzejczak ◽  
Bartosz Kempisty ◽  
Artur Bryja ◽  
M. Mostowska ◽  
Magdalena Depa-Martynow ◽  
...  
Keyword(s):  
Quantitative Assessment ◽  
Histone H1 ◽  
Linker Histone ◽  
Linker Histone H1
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