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Orsetti A, van Oosten D, Vasarhelyi RG, Dănescu TM, Huertas J, van Ingen H, Cojocaru V. Structural dynamics in chromatin unraveling by pioneer transcription factors. Biophys Rev 2024; 16:365-382. [PMID: 39099839 PMCID: PMC11297019 DOI: 10.1007/s12551-024-01205-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 06/18/2024] [Indexed: 08/06/2024] Open
Abstract
Pioneer transcription factors are proteins with a dual function. First, they regulate transcription by binding to nucleosome-free DNA regulatory elements. Second, they bind to DNA while wrapped around histone proteins in the chromatin and mediate chromatin opening. The molecular mechanisms that connect the two functions are yet to be discovered. In recent years, pioneer factors received increased attention mainly because of their crucial role in promoting cell fate transitions that could be used for regenerative therapies. For example, the three factors required to induce pluripotency in somatic cells, Oct4, Sox2, and Klf4 were classified as pioneer factors and studied extensively. With this increased attention, several structures of complexes between pioneer factors and chromatin structural units (nucleosomes) have been resolved experimentally. Furthermore, experimental and computational approaches have been designed to study two unresolved, key scientific questions: First, do pioneer factors induce directly local opening of nucleosomes and chromatin fibers upon binding? And second, how do the unstructured tails of the histones impact the structural dynamics involved in such conformational transitions? Here we review the current knowledge about transcription factor-induced nucleosome dynamics and the role of the histone tails in this process. We discuss what is needed to bridge the gap between the static views obtained from the experimental structures and the key structural dynamic events in chromatin opening. Finally, we propose that integrating nuclear magnetic resonance spectroscopy with molecular dynamics simulations is a powerful approach to studying pioneer factor-mediated dynamics of nucleosomes and perhaps small chromatin fibers using native DNA sequences.
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Affiliation(s)
- Andrea Orsetti
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Daphne van Oosten
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | | | - Theodor-Marian Dănescu
- Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Jan Huertas
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, England
| | - Hugo van Ingen
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Vlad Cojocaru
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
- STAR-UBB Institute, Babeş-Bolyai University, Cluj-Napoca, Romania
- Max Planck Institute for Molecular Biomedicine, Münster, Germany
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2
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Abasi LS, Elathram N, Movva M, Deep A, Corbett KD, Debelouchina GT. Phosphorylation regulates tau's phase separation behavior and interactions with chromatin. Commun Biol 2024; 7:251. [PMID: 38429335 PMCID: PMC10907630 DOI: 10.1038/s42003-024-05920-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/16/2024] [Indexed: 03/03/2024] Open
Abstract
Tau is a microtubule-associated protein often found in neurofibrillary tangles (NFTs) in the brains of patients with Alzheimer's disease. Beyond this context, mounting evidence suggests that tau localizes into the nucleus, where it may play a role in DNA protection and heterochromatin regulation. The molecular mechanisms behind these observations are currently unclear. Using in vitro biophysical experiments, here we demonstrate that tau can undergo liquid-liquid phase separation (LLPS) with DNA, mononucleosomes, and reconstituted nucleosome arrays under low salt conditions. Low concentrations of tau promote chromatin compaction and protect DNA from digestion. While the material state of samples at physiological salt is dominated by chromatin oligomerization, tau can still associate strongly and reversibly with nucleosome arrays. These properties are driven by tau's strong interactions with linker and nucleosomal DNA. In addition, tau co-localizes into droplets formed by nucleosome arrays and phosphorylated HP1α, a key heterochromatin constituent thought to function through an LLPS mechanism. Importantly, LLPS and chromatin interactions are disrupted by aberrant tau hyperphosphorylation. These biophysical properties suggest that tau may directly impact DNA and chromatin accessibility and that loss of these interactions could contribute to the aberrant nuclear effects seen in tau pathology.
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Affiliation(s)
- Lannah S Abasi
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Nesreen Elathram
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Manasi Movva
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Amar Deep
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Kevin D Corbett
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, 92093, USA
- Department of Molecular Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Galia T Debelouchina
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA.
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3
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Marunde MR, Fuchs HA, Burg JM, Popova IK, Vaidya A, Hall NW, Weinzapfel EN, Meiners MJ, Watson R, Gillespie ZB, Taylor HF, Mukhsinova L, Onuoha UC, Howard SA, Novitzky K, McAnarney ET, Krajewski K, Cowles MW, Cheek MA, Sun ZW, Venters BJ, Keogh MC, Musselman CA. Nucleosome conformation dictates the histone code. eLife 2024; 13:e78866. [PMID: 38319148 PMCID: PMC10876215 DOI: 10.7554/elife.78866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 02/05/2024] [Indexed: 02/07/2024] Open
Abstract
Histone post-translational modifications (PTMs) play a critical role in chromatin regulation. It has been proposed that these PTMs form localized 'codes' that are read by specialized regions (reader domains) in chromatin-associated proteins (CAPs) to regulate downstream function. Substantial effort has been made to define [CAP: histone PTM] specificities, and thus decipher the histone code and guide epigenetic therapies. However, this has largely been done using the reductive approach of isolated reader domains and histone peptides, which cannot account for any higher-order factors. Here, we show that the [BPTF PHD finger and bromodomain: histone PTM] interaction is dependent on nucleosome context. The tandem reader selectively associates with nucleosomal H3K4me3 and H3K14ac or H3K18ac, a combinatorial engagement that despite being in cis is not predicted by peptides. This in vitro specificity of the BPTF tandem reader for PTM-defined nucleosomes is recapitulated in a cellular context. We propose that regulatable histone tail accessibility and its impact on the binding potential of reader domains necessitates we refine the 'histone code' concept and interrogate it at the nucleosome level.
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Affiliation(s)
| | - Harrison A Fuchs
- Department of Biochemistry, University of Iowa Carver College of MedicineAuroraUnited States
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical CampusAuroraUnited States
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Krzysztof Krajewski
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel HillChapel HillUnited States
| | | | | | | | | | | | - Catherine A Musselman
- Department of Biochemistry, University of Iowa Carver College of MedicineAuroraUnited States
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical CampusAuroraUnited States
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4
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Lebedenko OO, Salikov VA, Izmailov SA, Podkorytov IS, Skrynnikov NR. Using NMR diffusion data to validate MD models of disordered proteins: Test case of N-terminal tail of histone H4. Biophys J 2024; 123:80-100. [PMID: 37990496 PMCID: PMC10808029 DOI: 10.1016/j.bpj.2023.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/28/2023] [Accepted: 11/17/2023] [Indexed: 11/23/2023] Open
Abstract
MD simulations can provide uniquely detailed models of intrinsically disordered proteins (IDPs). However, these models need careful experimental validation. The coefficient of translational diffusion Dtr, measurable by pulsed field gradient NMR, offers a potentially useful piece of experimental information related to the compactness of the IDP's conformational ensemble. Here, we investigate, both experimentally and via the MD modeling, the translational diffusion of a 25-residue N-terminal fragment from histone H4 (N-H4). We found that the predicted values of Dtr, as obtained from mean-square displacement of the peptide in the MD simulations, are largely determined by the viscosity of the MD water (which has been reinvestigated as a part of our study). Beyond that, our analysis of the diffusion data indicates that MD simulations of N-H4 in the TIP4P-Ew water give rise to an overly compact conformational ensemble for this peptide. In contrast, TIP4P-D and OPC simulations produce the ensembles that are consistent with the experimental Dtr result. These observations are supported by the analyses of the 15N spin relaxation rates. We also tested a number of empirical methods to predict Dtr based on IDP's coordinates extracted from the MD snapshots. In particular, we show that the popular approach involving the program HYDROPRO can produce misleading results. This happens because HYDROPRO is not intended to predict the diffusion properties of highly flexible biopolymers such as IDPs. Likewise, recent empirical schemes that exploit the relationship between the small-angle x-ray scattering-informed conformational ensembles of IDPs and the respective experimental Dtr values also prove to be problematic. In this sense, the first-principle calculations of Dtr from the MD simulations, such as demonstrated in this work, should provide a useful benchmark for future efforts in this area.
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Affiliation(s)
- Olga O Lebedenko
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Vladislav A Salikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Sergei A Izmailov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Ivan S Podkorytov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Nikolai R Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia; Department of Chemistry, Purdue University, West Lafayette, Indiana.
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5
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Abasi LS, Elathram N, Movva M, Deep A, Corbett KD, Debelouchina GT. Phosphorylation regulates tau's phase separation behavior and interactions with chromatin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.21.572911. [PMID: 38187700 PMCID: PMC10769318 DOI: 10.1101/2023.12.21.572911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Tau is a microtubule-associated protein often found in neurofibrillary tangles (NFTs) in the brains of patients with Alzheimer's disease (AD). Beyond this context, mounting evidence suggests that tau localizes into the nucleus, where it may play a role in DNA protection and heterochromatin regulation. Models of tau depletion or pathology show loss of genetically silent heterochromatin, aberrant expression of heterochromatic genes, and transposable element activation. The molecular mechanisms behind these observations are currently unclear. Using in vitro biophysical experiments, here we demonstrate that tau can undergo liquid-liquid phase separation (LLPS) with DNA, mononucleosomes, and reconstituted nucleosome arrays under low salt conditions. Low concentrations of tau promote chromatin compaction and protect DNA from digestion. While the material state of samples at physiological salt is dominated by chromatin oligomerization, tau can still associate strongly and reversibly with nucleosome arrays. These properties are driven by tau's strong interactions with linker and nucleosomal DNA, while magic angle spinning (MAS) solid-state NMR experiments show that tau binding does not drastically alter nucleosome structure and dynamics. In addition, tau co-localizes into droplets formed by nucleosome arrays and phosphorylated HP1α, a key heterochromatin constituent thought to function through an LLPS mechanism. Importantly, LLPS and chromatin interactions are disrupted by aberrant tau hyperphosphorylation. These biophysical properties suggest that tau may directly impact DNA and chromatin accessibility and that loss of these interactions could contribute to the aberrant nuclear effects seen in tau pathology.
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Affiliation(s)
- Lannah S. Abasi
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nesreen Elathram
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Manasi Movva
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Amar Deep
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kevin D. Corbett
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Galia T. Debelouchina
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
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6
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Sun W, Lebedenko OO, Salguero NG, Shannon MD, Zandian M, Poirier MG, Skrynnikov NR, Jaroniec CP. Conformational and Interaction Landscape of Histone H4 Tails in Nucleosomes Probed by Paramagnetic NMR Spectroscopy. J Am Chem Soc 2023; 145:25478-25485. [PMID: 37943892 PMCID: PMC10719895 DOI: 10.1021/jacs.3c10340] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
The fundamental repeat unit of chromatin, the nucleosome, consists of approximately 147 base pairs of double-stranded DNA and a histone protein octamer containing two copies each of histones H2A, H2B, H3, and H4. Each histone possesses a dynamically disordered N-terminal tail domain, and it is well-established that the tails of histones H3 and H4 play key roles in chromatin compaction and regulation. Here we investigate the conformational ensemble and interactions of the H4 tail in nucleosomes by means of solution NMR measurements of paramagnetic relaxation enhancements (PREs) in recombinant samples reconstituted with 15N-enriched H4 and nitroxide spin-label tagged H3. The experimental PREs, which report on the proximities of individual H4 tail residues to the different H3 spin-label sites, are interpreted by using microsecond time-scale molecular dynamics simulations of the nucleosome core particle. Collectively, these data enable improved localization of histone H4 tails in nucleosomes and support the notion that H4 tails engage in a fuzzy complex interaction with nucleosomal DNA.
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Affiliation(s)
- Wenjun Sun
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Olga O. Lebedenko
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg 199034, Russia
| | - Nicole Gonzalez Salguero
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Matthew D. Shannon
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Mohamad Zandian
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Michael G. Poirier
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - Nikolai R. Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg 199034, Russia
- Department of Chemistry, Purdue University, West Lafayette 47907, United States
| | - Christopher P. Jaroniec
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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7
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Shi X, Kannaian B, Prasanna C, Soman A, Nordenskiöld L. Structural and dynamical investigation of histone H2B in well-hydrated nucleosome core particles by solid-state NMR. Commun Biol 2023; 6:672. [PMID: 37355718 PMCID: PMC10290710 DOI: 10.1038/s42003-023-05050-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 06/16/2023] [Indexed: 06/26/2023] Open
Abstract
H2A-H2B dimer is a key component of nucleosomes and an important player in chromatin biology. Here, we characterized the structure and dynamics of H2B in precipitated nucleosome core particles (NCPs) with a physiologically relevant concentration using solid-state NMR. Our recent investigation of H3-H4 tetramer determined its unique dynamic properties and the present work provides a deeper understanding of the previously observed dynamic networks in NCP that is potentially functionally significant. Nearly complete 13C, 15N assignments were obtained for H2B R30-A121, which permit extracting unprecedented detailed structural and amino-acid site-specific dynamics. The derived structure of H2B in the well-hydrated NCP sample agrees well with that of X-ray crystals. Dynamics at different timescales were determined semi-quantitatively for H2B in a site-specific manner. Particularly, higher millisecond-microsecond dynamics are observed for H2B core regions including partial α1, L1, partial α2, and partial L3. The analysis of these regions in the context of the tertiary structure reveals the clustering of dynamical residues. Overall, this work fills a gap to a complete resonance assignment of all four histones in nucleosomes and delineates that the dynamic networks in NCP extend to H2B, which suggests a potential mechanism to couple histone core with distant DNA to modulate the DNA activities.
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Affiliation(s)
- Xiangyan Shi
- Department of Biology, Shenzhen MSU-BIT University, Shenzhen, Guangdong Province, China.
| | - Bhuvaneswari Kannaian
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Chinmayi Prasanna
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
| | - Aghil Soman
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Lars Nordenskiöld
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore.
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8
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Jennings CE, Zoss CJ, Morrison EA. Arginine anchor points govern H3 tail dynamics. Front Mol Biosci 2023; 10:1150400. [PMID: 37261328 PMCID: PMC10228543 DOI: 10.3389/fmolb.2023.1150400] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 04/11/2023] [Indexed: 06/02/2023] Open
Abstract
Chromatin is dynamically reorganized spatially and temporally, and the post-translational modification of histones is a key component of this regulation. The basic subunit of chromatin is the nucleosome core particle, consisting of two copies each of the histones H2A, H2B, H3, and H4 around which ∼147 base pairs of DNA wrap. The intrinsically disordered histone termini, or tails, protrude from the core and are heavily post-translationally modified. Previous studies have shown that the histone tails exist in dynamic ensembles of DNA-bound states within the nucleosome. Histone tail interactions with DNA are involved in nucleosome conformation and chromatin organization. Charge-modulating histone post-translational modifications (PTMs) are poised to perturb the dynamic interactions between histone tails and DNA. Arginine side chains form favorable interactions with DNA and are sites of charge-modulating PTMs such as citrullination. Our current focus is on the H3 tail, the longest histone tail. Four arginine residues are relatively evenly spaced along the H3 tail sequence, suggesting multivalent interactions with DNA poised for regulation by PTMs. In this study, we use NMR nuclear spin relaxation experiments to investigate the contribution of arginine residues to H3 tail dynamics within the nucleosome core particle. By neutralizing arginine via mutation to glutamine, we begin to work towards a comprehensive understanding of the contribution of individual residues to H3 tail dynamics. We find that neutralization of arginine residues results in increased regional mobility of the H3 tails, with implications for understanding the direct effects of arginine citrullination. Altogether, these studies support a role for dynamics within the histone language and emphasize the importance of charge-modulating histone PTMs in regulating chromatin dynamics, starting at the level of the basic subunit of chromatin.
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Affiliation(s)
- Christine E. Jennings
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Casey J. Zoss
- Medical Scientist Training Program, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Emma A. Morrison
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, United States
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9
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Kohestani H, Wereszczynski J. The effects of RNA.DNA-DNA triple helices on nucleosome structures and dynamics. Biophys J 2023; 122:1229-1239. [PMID: 36798026 PMCID: PMC10111275 DOI: 10.1016/j.bpj.2023.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 01/22/2023] [Accepted: 02/10/2023] [Indexed: 02/17/2023] Open
Abstract
Noncoding RNAs (ncRNAs) are an emerging epigenetic factor and have been recognized as playing a key role in many gene expression pathways. Structurally, binding of ncRNAs to isolated DNA is strongly dependent on sequence complementary and results in the formation of an RNA.DNA-DNA (RDD) triple helix. However, in vivo DNA is not isolated but is rather packed in chromatin fibers, the fundamental unit of which is the nucleosome. Biochemical experiments have shown that ncRNA binding to nucleosomal DNA is elevated at DNA entry and exit sites and is dependent on the presence of the H3 N-terminal tails. However, the structural and dynamical bases for these mechanisms remain unknown. Here, we have examined the mechanisms and effects of RDD formation in the context of the nucleosome using a series of all-atom molecular dynamics simulations. Results highlight the importance of DNA sequence on complex stability, elucidate the effects of the H3 tails on RDD structures, show how RDD formation impacts the structure and dynamics of the H3 tails, and show how RNA alters the local and global DNA double-helical structure. Together, our results suggest ncRNAs can modify nucleosome, and potentially higher-order chromatin, structures and dynamics as a means of exerting epigenetic control.
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Affiliation(s)
- Havva Kohestani
- Department of Biology, Illinois Institute of Technology, Chicago, Illinois
| | - Jeff Wereszczynski
- Departments of Physics & Biology, Illinois Institute of Technology, Chicago, Illinois.
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10
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Zhang S, Li J, Xu Q, Xia W, Tao Y, Shi C, Li D, Xiang S, Liu C. Conformational Dynamics of an α-Synuclein Fibril upon Receptor Binding Revealed by Insensitive Nuclei Enhanced by Polarization Transfer-Based Solid-State Nuclear Magnetic Resonance and Cryo-Electron Microscopy. J Am Chem Soc 2023; 145:4473-4484. [PMID: 36794997 DOI: 10.1021/jacs.2c10854] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Many amyloid fibrils associated with neurodegenerative diseases consist of an ordered fibril core (FC) and disordered terminal regions (TRs). The former represents a stable scaffold, while the latter is rather active in binding with various partners. Current structural studies mainly focus on the ordered FC since the high flexibility of TRs hinders structural characterization. Here, by combining insensitive nuclei enhanced by polarization transfer-based 1H-detected solid-state NMR and cryo-EM, we explored the intact structure of an α-syn fibril including both FC and TRs and further studied the conformational dynamics of the fibril upon binding to lymphocyte activation gene 3 (LAG3)─a cell surface receptor that is involved in α-syn fibril transmission in brains. We found that both the N- and C-TRs of α-syn are disordered in free fibrils featuring similar conformation ensembles as those in soluble monomers. While in the presence of the D1 domain of LAG3 (L3D1), the C-TR directly binds to L3D1, meanwhile the N-TR folds into a β-strand and further integrates with the FC, which leads to alteration of the overall fibril structure and surface property. Our work reveals synergistic conformational transition of the intrinsically disordered TRs of α-syn, which sheds light on mechanistic understanding of the essential role of TRs in regulating the structure and pathology of amyloid fibrils.
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Affiliation(s)
- Shengnan Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Juan Li
- MOE Key Lab for Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026 Anhui, China
| | - Qianhui Xu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Wencheng Xia
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Youqi Tao
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Chaowei Shi
- MOE Key Lab for Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026 Anhui, China
| | - Dan Li
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai 200030, China.,Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
| | - ShengQi Xiang
- MOE Key Lab for Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026 Anhui, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,State Key Laboratory of Bio-Organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
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11
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Smrt ST, Gonzalez Salguero N, Thomas JK, Zandian M, Poirier MG, Jaroniec CP. Histone H3 core domain in chromatin with different DNA linker lengths studied by 1H-Detected solid-state NMR spectroscopy. Front Mol Biosci 2023; 9:1106588. [PMID: 36660422 PMCID: PMC9846530 DOI: 10.3389/fmolb.2022.1106588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 12/20/2022] [Indexed: 01/06/2023] Open
Abstract
Chromatin, a dynamic protein-DNA complex that regulates eukaryotic genome accessibility and essential functions, is composed of nucleosomes connected by linker DNA with each nucleosome consisting of DNA wrapped around an octamer of histones H2A, H2B, H3 and H4. Magic angle spinning solid-state nuclear magnetic resonance (NMR) spectroscopy can yield unique insights into histone structure and dynamics in condensed nucleosomes and nucleosome arrays representative of chromatin at physiological concentrations. Recently we used J-coupling-based solid-state NMR methods to investigate with residue-specific resolution the conformational dynamics of histone H3 N-terminal tails in 16-mer nucleosome arrays containing 15, 30 or 60 bp DNA linkers. Here, we probe the H3 core domain in the 16-mer arrays as a function of DNA linker length via dipolar coupling-based 1H-detected solid-state NMR techniques. Specifically, we established nearly complete assignments of backbone chemical shifts for H3 core residues in arrays with 15-60 bp DNA linkers reconstituted with 2H,13C,15N-labeled H3. Overall, these chemical shifts were similar irrespective of the DNA linker length indicating no major changes in H3 core conformation. Notably, however, multiple residues at the H3-nucleosomal DNA interface in arrays with 15 bp DNA linkers exhibited relatively pronounced differences in chemical shifts and line broadening compared to arrays with 30 and 60 bp linkers. These findings are consistent with increased heterogeneity in nucleosome packing and structural strain within arrays containing short DNA linkers that likely leads to side-chains of these interfacial residues experiencing alternate conformations or shifts in their rotamer populations relative to arrays with the longer DNA linkers.
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Affiliation(s)
- Sean T. Smrt
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, United States
| | - Nicole Gonzalez Salguero
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, United States
| | - Justin K. Thomas
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, United States
| | - Mohamad Zandian
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, United States
| | - Michael G. Poirier
- Department of Physics, The Ohio State University, Columbus, OH, United States
| | - Christopher P. Jaroniec
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, United States,*Correspondence: Christopher P. Jaroniec,
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12
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Conroy DW, Xu Y, Shi H, Gonzalez Salguero N, Purusottam RN, Shannon MD, Al-Hashimi HM, Jaroniec CP. Probing Watson-Crick and Hoogsteen base pairing in duplex DNA using dynamic nuclear polarization solid-state NMR spectroscopy. Proc Natl Acad Sci U S A 2022; 119:e2200681119. [PMID: 35857870 PMCID: PMC9335254 DOI: 10.1073/pnas.2200681119] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The majority of base pairs in double-stranded DNA exist in the canonical Watson-Crick geometry. However, they can also adopt alternate Hoogsteen conformations in various complexes of DNA with proteins and small molecules, which are key for biological function and mechanism. While detection of Hoogsteen base pairs in large DNA complexes and assemblies poses considerable challenges for traditional structural biology techniques, we show here that multidimensional dynamic nuclear polarization-enhanced solid-state NMR can serve as a unique spectroscopic tool for observing and distinguishing Watson-Crick and Hoogsteen base pairs in a broad range of DNA systems based on characteristic NMR chemical shifts and internuclear dipolar couplings. We illustrate this approach using a model 12-mer DNA duplex, free and in complex with the antibiotic echinomycin, which features two central adenine-thymine base pairs with Watson-Crick and Hoogsteen geometry, respectively, and subsequently extend it to the ∼200 kDa Widom 601 DNA nucleosome core particle.
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Affiliation(s)
- Daniel W. Conroy
- aDepartment of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210
| | - Yu Xu
- bDepartment of Chemistry, Duke University, Durham, NC 27708
| | - Honglue Shi
- bDepartment of Chemistry, Duke University, Durham, NC 27708
| | | | - Rudra N. Purusottam
- aDepartment of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210
| | - Matthew D. Shannon
- aDepartment of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210
| | - Hashim M. Al-Hashimi
- bDepartment of Chemistry, Duke University, Durham, NC 27708
- cDepartment of Biochemistry, Duke University Medical Center, Durham, NC 27710
- dDepartment of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032
- 1To whom correspondence may be addressed. or
| | - Christopher P. Jaroniec
- aDepartment of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210
- 1To whom correspondence may be addressed. or
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13
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Elathram N, Ackermann BE, Debelouchina GT. DNP-enhanced solid-state NMR spectroscopy of chromatin polymers. JOURNAL OF MAGNETIC RESONANCE OPEN 2022; 10-11:100057. [PMID: 35707629 PMCID: PMC9191766 DOI: 10.1016/j.jmro.2022.100057] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Chromatin is a DNA-protein polymer that represents the functional form of the genome. The main building block of chromatin is the nucleosome, a structure that contains 147 base pairs of DNA and two copies each of the histone proteins H2A, H2B, H3 and H4. Previous work has shown that magic angle spinning (MAS) NMR spectroscopy can capture the nucleosome at high resolution although studies have been challenging due to low sensitivity, the presence of dynamic and rigid components, and the complex interaction networks of nucleosomes within the chromatin polymer. Here, we use dynamic nuclear polarization (DNP) to enhance the sensitivity of MAS NMR experiments of nucleosome arrays at 100 K and show that well-resolved 13C-13C MAS NMR correlations can be obtained much more efficiently. We evaluate the effect of temperature on the chemical shifts and linewidths in the spectra and demonstrate that changes are relatively minimal and clustered in regions of histone-DNA or histone-histone contacts. We also compare samples prepared with and without DNA and show that the low temperature 13C-13C correlations exhibit sufficient resolution to detect chemical shift changes and line broadening for residues that form the DNA-histone interface. On the other hand, we show that the measurement of DNP-enhanced 15N-13C histone-histone interactions within the nucleosome core is complicated by the natural 13C abundance network in the sample. Nevertheless, the enhanced sensitivity afforded by DNP can be used to detect long-range correlations between histone residues and DNA. Overall, our experiments demonstrate that DNP-enhanced MAS NMR spectroscopy of chromatin samples yields spectra with high resolution and sensitivity and can be used to capture functionally relevant protein-DNA interactions that have implications for gene regulation and genome organization.
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Affiliation(s)
| | | | - Galia T. Debelouchina
- Corresponding author: Galia Debelouchina, University of California, San Diego, Natural Sciences Building 4322, 9500 Gilman Dr., La Jolla, CA 92093, 858-534-3038,
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14
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Shi X, Zhai Z, Chen Y, Li J, Nordenskiöld L. Recent Advances in Investigating Functional Dynamics of Chromatin. Front Genet 2022; 13:870640. [PMID: 35450211 PMCID: PMC9017861 DOI: 10.3389/fgene.2022.870640] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/11/2022] [Indexed: 11/26/2022] Open
Abstract
Dynamics spanning the picosecond-minute time domain and the atomic-subcellular spatial window have been observed for chromatin in vitro and in vivo. The condensed organization of chromatin in eukaryotic cells prevents regulatory factors from accessing genomic DNA, which requires dynamic stabilization and destabilization of structure to initiate downstream DNA activities. Those processes are achieved through altering conformational and dynamic properties of nucleosomes and nucleosome–protein complexes, of which delineating the atomistic pictures is essential to understand the mechanisms of chromatin regulation. In this review, we summarize recent progress in determining chromatin dynamics and their modulations by a number of factors including post-translational modifications (PTMs), incorporation of histone variants, and binding of effector proteins. We focus on experimental observations obtained using high-resolution techniques, primarily including nuclear magnetic resonance (NMR) spectroscopy, Förster (or fluorescence) resonance energy transfer (FRET) microscopy, and molecular dynamics (MD) simulations, and discuss the elucidated dynamics in the context of functional response and relevance.
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Affiliation(s)
- Xiangyan Shi
- Department of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Ziwei Zhai
- Department of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Yinglu Chen
- Department of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Jindi Li
- Department of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Lars Nordenskiöld
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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15
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Musselman CA, Kutateladze TG. Visualizing Conformational Ensembles of the Nucleosome by NMR. ACS Chem Biol 2022; 17:495-502. [PMID: 35196453 DOI: 10.1021/acschembio.1c00954] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The formation of chromatin not only compacts the eukaryotic genome into the nucleus but also provides a mechanism for the regulation of all DNA templated processes. Spatial and temporal modulation of the chromatin structure is critical in such regulation and involves fine-tuned functioning of the basic subunit of chromatin, the nucleosome. It has become apparent that the nucleosome is an inherently dynamic system, but characterization of these dynamics at the atomic level has remained challenging. NMR spectroscopy is a powerful tool for investigating the conformational ensemble and dynamics of proteins and protein complexes, and recent advances have made the study of large systems possible. Here, we review recent studies which utilize NMR spectroscopy to uncover the atomic level conformation and dynamics of the nucleosome and provide a better understanding of the importance of these dynamics in key regulatory events.
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Affiliation(s)
- Catherine A. Musselman
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, United States
| | - Tatiana G. Kutateladze
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045, United States
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16
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Morvan D, Cachin F. Untargeted 2D NMR Metabolomics of [ 13C- methyl]Methionine-Labeled Tumor Models Reveals the Non-DNA Methylome and Provides Clues to Methyl Metabolism Shift during Tumor Progression. J Proteome Res 2022; 21:940-952. [PMID: 35196455 PMCID: PMC8981308 DOI: 10.1021/acs.jproteome.1c00778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
For more than a decade, DNA and histone methylations have been the focus of extensive work, although their relationship with methyl group metabolism was overlooked. Recently, it has emerged that epigenetic methylations are influenced by methyl donor nutrient availability, cellular levels of S-adenosyl-methionine (SAM), and cytoplasmic methyltransferase activities. SAM-dependent methyltransferases methylate a wide range of targets, from small molecules to proteins and nucleic acids. However, few investigations of the global methylome of tumors have been performed. Here, untargeted NMR metabolomics of two mouse tumor models labeled with [13C-methyl]methionine were used to search for the NMR-visible set of cellular methyl acceptors denoted the global methylome. Tumor models were B16 melanoma cell cultures and B16 melanoma tumors, which may be considered as two stages of B16 tumor development. Based on 2D 1H-13C NMR spectra and orthogonal partial least squares discriminant analysis of spectra, our study revealed markedly different global methylomes for melanoma models. The methylome of B16 melanoma cell cultures was dominated by histone methylations, whereas that of B16 melanoma tumors was dominated by cytoplasmic small-molecule methylations. Overall, the technique gave access to the non-DNA methylome. Comparison of tumor models also exhibiting differential expression of aerobic glycolysis provided clues to a methyl metabolism shift during tumor progression.
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Affiliation(s)
- Daniel Morvan
- UCA University, Boulevard François Mitterrand, 63001 Clermont-Ferrand, France.,Comprehensive Cancer Centre Jean Perrin, rue Montalembert, 63011 Clermont-Ferrand, France
| | - Florent Cachin
- UCA University, Boulevard François Mitterrand, 63001 Clermont-Ferrand, France.,Comprehensive Cancer Centre Jean Perrin, rue Montalembert, 63011 Clermont-Ferrand, France.,Inserm UMR 1240 IMOST, rue Montalembert, 63011 Clermont-Ferrand, France
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17
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Kanapeckaitė A, Burokienė N, Mažeikienė A, Cottrell GS, Widera D. Biophysics is reshaping our perception of the epigenome: from DNA-level to high-throughput studies. BIOPHYSICAL REPORTS 2021; 1:100028. [PMID: 36425454 PMCID: PMC9680810 DOI: 10.1016/j.bpr.2021.100028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 09/24/2021] [Indexed: 06/16/2023]
Abstract
Epigenetic research holds great promise to advance our understanding of biomarkers and regulatory processes in health and disease. An increasing number of new approaches, ranging from molecular to biophysical analyses, enable identifying epigenetic changes on the level of a single gene or the whole epigenome. The aim of this review is to highlight how the field is shifting from completely molecular-biology-driven solutions to multidisciplinary strategies including more reliance on biophysical analysis tools. Biophysics not only offers technical advancements in imaging or structure analysis but also helps to explore regulatory interactions. New computational methods are also being developed to meet the demand of growing data volumes and their processing. Therefore, it is important to capture these new directions in epigenetics from a biophysical perspective and discuss current challenges as well as multiple applications of biophysical methods and tools. Specifically, we gradually introduce different biophysical research methods by first considering the DNA-level information and eventually higher-order chromatin structures. Moreover, we aim to highlight that the incorporation of bioinformatics, machine learning, and artificial intelligence into biophysical analysis allows gaining new insights into complex epigenetic processes. The gained understanding has already proven useful in translational and clinical research providing better patient stratification options or new therapeutic insights. Together, this offers a better readiness to transform bench-top experiments into industrial high-throughput applications with a possibility to employ developed methods in clinical practice and diagnostics.
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Affiliation(s)
- Austė Kanapeckaitė
- Algorithm379, Laisvės g. 7, LT 12007, Vilnius, Lithuania
- Reading School of Pharmacy, Whiteknights, Reading, UK, RG6 6UB
| | - Neringa Burokienė
- Clinics of Internal Diseases, Family Medicine and Oncology, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, M. K. Čiurlionio str. 21/27, LT-03101 Vilnius, Lithuania
| | - Asta Mažeikienė
- Department of Physiology, Biochemistry, Microbiology and Laboratory Medicine, Institute of Biomedical Sciences, Faculty of Medicine, M. K. Čiurlionio str. 21/27, LT-03101 Vilnius, Lithuania
| | | | - Darius Widera
- Reading School of Pharmacy, Whiteknights, Reading, UK, RG6 6UB
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18
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Ackermann BE, Debelouchina GT. Emerging Contributions of Solid-State NMR Spectroscopy to Chromatin Structural Biology. Front Mol Biosci 2021; 8:741581. [PMID: 34708075 PMCID: PMC8544521 DOI: 10.3389/fmolb.2021.741581] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/20/2021] [Indexed: 11/13/2022] Open
Abstract
The eukaryotic genome is packaged into chromatin, a polymer of DNA and histone proteins that regulates gene expression and the spatial organization of nuclear content. The repetitive character of chromatin is diversified into rich layers of complexity that encompass DNA sequence, histone variants and post-translational modifications. Subtle molecular changes in these variables can often lead to global chromatin rearrangements that dictate entire gene programs with far reaching implications for development and disease. Decades of structural biology advances have revealed the complex relationship between chromatin structure, dynamics, interactions, and gene expression. Here, we focus on the emerging contributions of magic-angle spinning solid-state nuclear magnetic resonance spectroscopy (MAS NMR), a relative newcomer on the chromatin structural biology stage. Unique among structural biology techniques, MAS NMR is ideally suited to provide atomic level information regarding both the rigid and dynamic components of this complex and heterogenous biological polymer. In this review, we highlight the advantages MAS NMR can offer to chromatin structural biologists, discuss sample preparation strategies for structural analysis, summarize recent MAS NMR studies of chromatin structure and dynamics, and close by discussing how MAS NMR can be combined with state-of-the-art chemical biology tools to reconstitute and dissect complex chromatin environments.
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Affiliation(s)
| | - Galia T. Debelouchina
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, United States
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19
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Peng Y, Li S, Onufriev A, Landsman D, Panchenko AR. Binding of regulatory proteins to nucleosomes is modulated by dynamic histone tails. Nat Commun 2021; 12:5280. [PMID: 34489435 PMCID: PMC8421395 DOI: 10.1038/s41467-021-25568-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 08/17/2021] [Indexed: 12/19/2022] Open
Abstract
Little is known about the roles of histone tails in modulating nucleosomal DNA accessibility and its recognition by other macromolecules. Here we generate extensive atomic level conformational ensembles of histone tails in the context of the full nucleosome, totaling 65 microseconds of molecular dynamics simulations. We observe rapid conformational transitions between tail bound and unbound states, and characterize kinetic and thermodynamic properties of histone tail-DNA interactions. Different histone types exhibit distinct binding modes to specific DNA regions. Using a comprehensive set of experimental nucleosome complexes, we find that the majority of them target mutually exclusive regions with histone tails on nucleosomal/linker DNA around the super-helical locations ± 1, ± 2, and ± 7, and histone tails H3 and H4 contribute most to this process. These findings are explained within competitive binding and tail displacement models. Finally, we demonstrate the crosstalk between different histone tail post-translational modifications and mutations; those which change charge, suppress tail-DNA interactions and enhance histone tail dynamics and DNA accessibility. The intrinsic disorder of histone tails poses challenges in their characterization. Here the authors apply extensive molecular dynamics simulations of the full nucleosome to show reversible binding to DNA with specific binding modes of different types of histone tails, where charge-altering modifications suppress tail-DNA interactions and may boost interactions between nucleosomes and nucleosome-binding proteins.
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Affiliation(s)
- Yunhui Peng
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA
| | - Shuxiang Li
- Department of Pathology and Molecular Medicine, School of Medicine, Queen's University, Kingston, ON, Canada
| | - Alexey Onufriev
- Physics Department, Virginia Tech, VA, USA.,Computer Science Department, Virginia Tech, VA, USA.,Center for Soft Matter and Biological Physics, Virginia Tech, VA, USA
| | - David Landsman
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA
| | - Anna R Panchenko
- Department of Pathology and Molecular Medicine, School of Medicine, Queen's University, Kingston, ON, Canada.
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20
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Shoaib M, Chen Q, Shi X, Nair N, Prasanna C, Yang R, Walter D, Frederiksen KS, Einarsson H, Svensson JP, Liu CF, Ekwall K, Lerdrup M, Nordenskiöld L, Sørensen CS. Histone H4 lysine 20 mono-methylation directly facilitates chromatin openness and promotes transcription of housekeeping genes. Nat Commun 2021; 12:4800. [PMID: 34417450 PMCID: PMC8379281 DOI: 10.1038/s41467-021-25051-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 07/15/2021] [Indexed: 12/26/2022] Open
Abstract
Histone lysine methylations have primarily been linked to selective recruitment of reader or effector proteins that subsequently modify chromatin regions and mediate genome functions. Here, we describe a divergent role for histone H4 lysine 20 mono-methylation (H4K20me1) and demonstrate that it directly facilitates chromatin openness and accessibility by disrupting chromatin folding. Thus, accumulation of H4K20me1 demarcates highly accessible chromatin at genes, and this is maintained throughout the cell cycle. In vitro, H4K20me1-containing nucleosomal arrays with nucleosome repeat lengths (NRL) of 187 and 197 are less compact than unmethylated (H4K20me0) or trimethylated (H4K20me3) arrays. Concordantly, and in contrast to trimethylated and unmethylated tails, solid-state NMR data shows that H4K20 mono-methylation changes the H4 conformational state and leads to more dynamic histone H4-tails. Notably, the increased chromatin accessibility mediated by H4K20me1 facilitates gene expression, particularly of housekeeping genes. Altogether, we show how the methylation state of a single histone H4 residue operates as a focal point in chromatin structure control. While H4K20me1 directly promotes chromatin openness at highly transcribed genes, it also serves as a stepping-stone for H4K20me3-dependent chromatin compaction. The effect of histone H4 lysine 20 methylation (H4K20me) on chromatin accessibility are not well established. Here the authors show how H4K20 methylation regulates chromatin structure and accessibility to ensure precise transcriptional outputs through the cell cycle using genome-wide approaches, in vitro biophysical assays, and NMR.
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Affiliation(s)
- Muhammad Shoaib
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Biology, SBA School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Qinming Chen
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Xiangyan Shi
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Nidhi Nair
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chinmayi Prasanna
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Renliang Yang
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Wilmar International Limited, Jurong Island, Singapore
| | - David Walter
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Hjorleifur Einarsson
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - J Peter Svensson
- Department of Biosciences and Nutrition, Karolinska Institute, Huddinge, Sweden
| | - Chuan Fa Liu
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Karl Ekwall
- Department of Biosciences and Nutrition, Karolinska Institute, Huddinge, Sweden
| | - Mads Lerdrup
- Center for Chromosome Stability, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Lars Nordenskiöld
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
| | - Claus S Sørensen
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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21
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Zandian M, Salguero NG, Shannon MD, Purusottam RN, Theint T, Poirier MG, Jaroniec CP. Conformational Dynamics of Histone H3 Tails in Chromatin. J Phys Chem Lett 2021; 12:6174-6181. [PMID: 34184895 PMCID: PMC8788308 DOI: 10.1021/acs.jpclett.1c01187] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Chromatin is a supramolecular DNA-protein complex that compacts eukaryotic genomes and regulates their accessibility and functions. Dynamically disordered histone H3 N-terminal tails are among key chromatin regulatory components. Here, we used high-resolution-magic-angle-spinning NMR measurements of backbone amide 15N spin relaxation rates to investigate, with residue-specific detail, the dynamics and interactions of H3 tails in recombinant 13C,15N-enriched nucleosome arrays containing 15, 30, or 60 bp linker DNA between the nucleosome repeats. These measurements were compared to analogous data available for mononucleosomes devoid of linker DNA or containing two 20 bp DNA overhangs. The H3 tail dynamics in nucleosome arrays were found to be considerably attenuated compared with nucleosomes with or without linker DNA due to transient electrostatic interactions with the linker DNA segments and the structured chromatin environment. Remarkably, however, the H3 tail dynamics were not modulated by the specific linker DNA length within the 15-60 bp range investigated here.
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Affiliation(s)
- Mohamad Zandian
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210
| | | | - Matthew D. Shannon
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210
| | - Rudra N. Purusottam
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210
| | - Theint Theint
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210
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22
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Röder K. Is the H4 histone tail intrinsically disordered or intrinsically multifunctional? Phys Chem Chem Phys 2021; 23:5134-5142. [PMID: 33624669 DOI: 10.1039/d0cp05405d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The structural versatility of histone tails is one of the key elements in the organisation of chromatin, which allows for the compact storage of genomic information. However, this structural diversity also complicates experimental and computational studies. Here, the potential and free energy landscape for the isolated and bound H4 histone tail are explored. The landscapes exhibit a set of distinct structural ensembles separated by high energy barriers, with little difference between isolated and bound tails. This consistency is a desirable feature that facilitates the formation of transient interactions, which are required for the liquid-like chromatin organisation. The existence of multiple, distinct structures on a multifunnel energy landscape is likely to be associated with multifunctionality, i.e. a set of evolved, distinct functions. Contrasting it with previously reported results for other disordered peptides, this type of landscape may be associated with a conformational selection based binding mechanism. Given the similarity to other systems exhibiting similar multifunnel energy landscapes, the disorder in histone tails might be better described in context of multifunctionality.
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Affiliation(s)
- Konstantin Röder
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
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23
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Ohtomo H, Kurita JI, Sakuraba S, Li Z, Arimura Y, Wakamori M, Tsunaka Y, Umehara T, Kurumizaka H, Kono H, Nishimura Y. The N-terminal Tails of Histones H2A and H2B Adopt Two Distinct Conformations in the Nucleosome with Contact and Reduced Contact to DNA. J Mol Biol 2021; 433:167110. [PMID: 34153285 DOI: 10.1016/j.jmb.2021.167110] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 06/11/2021] [Accepted: 06/11/2021] [Indexed: 11/28/2022]
Abstract
The nucleosome comprises two histone dimers of H2A-H2B and one histone tetramer of (H3-H4)2, wrapped around by ~145 bp of DNA. Detailed core structures of nucleosomes have been established by X-ray and cryo-EM, however, histone tails have not been visualized. Here, we have examined the dynamic structures of the H2A and H2B tails in 145-bp and 193-bp nucleosomes using NMR, and have compared them with those of the H2A and H2B tail peptides unbound and bound to DNA. Whereas the H2A C-tail adopts a single but different conformation in both nucleosomes, the N-tails of H2A and H2B adopt two distinct conformations in each nucleosome. To clarify these conformations, we conducted molecular dynamics (MD) simulations, which suggest that the H2A N-tail can locate stably in either the major or minor grooves of nucleosomal DNA. While the H2B N-tail, which sticks out between two DNA gyres in the nucleosome, was considered to adopt two different orientations, one toward the entry/exit side and one on the opposite side. Then, the H2A N-tail minor groove conformation was obtained in the H2B opposite side and the H2B N-tail interacts with DNA similarly in both sides, though more varied conformations are obtained in the entry/exit side. Collectively, the NMR findings and MD simulations suggest that the minor groove conformer of the H2A N-tail is likely to contact DNA more strongly than the major groove conformer, and the H2A N-tail reduces contact with DNA in the major groove when the H2B N-tail is located in the entry/exit side.
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Affiliation(s)
- Hideaki Ohtomo
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Jun-Ichi Kurita
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Shun Sakuraba
- Institute for Quantum Life Science (iQLS), National Institutes for Quantum and Radiological Science and Technology (QST), 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
| | - Zhenhai Li
- Institute for Quantum Life Science (iQLS), National Institutes for Quantum and Radiological Science and Technology (QST), 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
| | - Yasuhiro Arimura
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Masatoshi Wakamori
- Laboratory for Epigenetics Drug Discovery, RIKEN Center for Biosystems Dynamics Research (BDR), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Yasuo Tsunaka
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Takashi Umehara
- Laboratory for Epigenetics Drug Discovery, RIKEN Center for Biosystems Dynamics Research (BDR), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Hidetoshi Kono
- Institute for Quantum Life Science (iQLS), National Institutes for Quantum and Radiological Science and Technology (QST), 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
| | - Yoshifumi Nishimura
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan; Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739-8258, Japan.
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24
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Rabdano SO, Shannon MD, Izmailov SA, Gonzalez Salguero N, Zandian M, Purusottam RN, Poirier MG, Skrynnikov NR, Jaroniec CP. Histone H4 Tails in Nucleosomes: a Fuzzy Interaction with DNA. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202012046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Sevastyan O. Rabdano
- Laboratory of Biomolecular NMR St. Petersburg State University St. Petersburg 199034 Russian Federation
| | - Matthew D. Shannon
- Department of Chemistry and Biochemistry The Ohio State University Columbus OH 43210 USA
| | - Sergei A. Izmailov
- Laboratory of Biomolecular NMR St. Petersburg State University St. Petersburg 199034 Russian Federation
| | | | - Mohamad Zandian
- Department of Chemistry and Biochemistry The Ohio State University Columbus OH 43210 USA
| | - Rudra N. Purusottam
- Department of Chemistry and Biochemistry The Ohio State University Columbus OH 43210 USA
| | | | - Nikolai R. Skrynnikov
- Laboratory of Biomolecular NMR St. Petersburg State University St. Petersburg 199034 Russian Federation
- Department of Chemistry Purdue University West Lafayette IN 47906 USA
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25
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Rabdano SO, Shannon MD, Izmailov SA, Gonzalez Salguero N, Zandian M, Purusottam RN, Poirier MG, Skrynnikov NR, Jaroniec CP. Histone H4 Tails in Nucleosomes: a Fuzzy Interaction with DNA. Angew Chem Int Ed Engl 2021; 60:6480-6487. [PMID: 33522067 DOI: 10.1002/anie.202012046] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/15/2020] [Indexed: 12/21/2022]
Abstract
The interaction of positively charged N-terminal histone tails with nucleosomal DNA plays an important role in chromatin assembly and regulation, modulating their susceptibility to post-translational modifications and recognition by chromatin-binding proteins. Here, we report residue-specific 15 N NMR relaxation rates for histone H4 tails in reconstituted nucleosomes. These data indicate that H4 tails are strongly dynamically disordered, albeit with reduced conformational flexibility compared to a free peptide with the same sequence. Remarkably, the NMR observables were successfully reproduced in a 2-μs MD trajectory of the nucleosome. This is an important step toward resolving an apparent inconsistency where prior simulations were generally at odds with experimental evidence on conformational dynamics of histone tails. Our findings indicate that histone H4 tails engage in a fuzzy interaction with nucleosomal DNA, underpinned by a variable pattern of short-lived salt bridges and hydrogen bonds, which persists at low ionic strength (0-100 mM NaCl).
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Affiliation(s)
- Sevastyan O Rabdano
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, 199034, Russian Federation
| | - Matthew D Shannon
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Sergei A Izmailov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, 199034, Russian Federation
| | | | - Mohamad Zandian
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Rudra N Purusottam
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Michael G Poirier
- Department of Physics, The Ohio State University, Columbus, OH, 43210, USA
| | - Nikolai R Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, 199034, Russian Federation.,Department of Chemistry, Purdue University, West Lafayette, IN, 47906, USA
| | - Christopher P Jaroniec
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
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26
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Ghoneim M, Fuchs HA, Musselman CA. Histone Tail Conformations: A Fuzzy Affair with DNA. Trends Biochem Sci 2021; 46:564-578. [PMID: 33551235 DOI: 10.1016/j.tibs.2020.12.012] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/23/2020] [Accepted: 12/23/2020] [Indexed: 12/13/2022]
Abstract
The core histone tails are critical in chromatin structure and signaling. Studies over the past several decades have provided a wealth of information on the histone tails and their interaction with chromatin factors. However, the conformation of the histone tails in a chromatin relevant context has remained elusive. Only recently has enough evidence emerged to start to build a structural model of the tails in the context of nucleosomes and nucleosome arrays. Here, we review these studies and propose that the histone tails adopt a high-affinity fuzzy complex with DNA, characterized by robust but dynamic association. Furthermore, we discuss how these DNA-bound conformational ensembles promote distinct chromatin structure and signaling, and that their fuzzy nature is important in transitioning between functional states.
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Affiliation(s)
- Mohamed Ghoneim
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Harrison A Fuchs
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Catherine A Musselman
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
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27
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le Paige UB, Xiang S, Hendrix MMRM, Zhang Y, Folkers GE, Weingarth M, Bonvin AMJJ, Kutateladze TG, Voets IK, Baldus M, van Ingen H. Characterization of nucleosome sediments for protein interaction studies by solid-state NMR spectroscopy. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2021; 2:187-202. [PMID: 35647606 PMCID: PMC9135053 DOI: 10.5194/mr-2-187-2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Regulation of DNA-templated processes such as gene transcription and DNA repair depend on the interaction of a wide range of proteins with the nucleosome, the fundamental building block of chromatin. Both solution and solid-state NMR spectroscopy have become an attractive approach to study the dynamics and interactions of nucleosomes, despite their high molecular weight of ~ 200 kDa. For solid-state NMR (ssNMR) studies, dilute solutions of nucleosomes are converted to a dense phase by sedimentation or precipitation. Since nucleosomes are known to self-associate, these dense phases may induce extensive interactions between nucleosomes, which could interfere with protein-binding studies. Here, we characterized the packing of nucleosomes in the dense phase created by sedimentation using NMR and small-angle X-ray scattering (SAXS) experiments. We found that nucleosome sediments are gels with variable degrees of solidity, have nucleosome concentration close to that found in crystals, and are stable for weeks under high-speed magic angle spinning (MAS). Furthermore, SAXS data recorded on recovered sediments indicate that there is no pronounced long-range ordering of nucleosomes in the sediment. Finally, we show that the sedimentation approach can also be used to study low-affinity protein interactions with the nucleosome. Together, our results give new insights into the sample characteristics of nucleosome sediments for ssNMR studies and illustrate the broad applicability of sedimentation-based NMR studies.
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Affiliation(s)
- Ulric B. le Paige
- Utrecht NMR Group, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH, Utrecht, the Netherlands
| | - ShengQi Xiang
- Utrecht NMR Group, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH, Utrecht, the Netherlands
| | - Marco M. R. M. Hendrix
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry & Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, the Netherlands
| | - Yi Zhang
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Gert E. Folkers
- Utrecht NMR Group, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH, Utrecht, the Netherlands
| | - Markus Weingarth
- Utrecht NMR Group, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH, Utrecht, the Netherlands
| | - Alexandre M. J. J. Bonvin
- Utrecht NMR Group, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH, Utrecht, the Netherlands
| | - Tatiana G. Kutateladze
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Ilja K. Voets
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry & Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, the Netherlands
| | - Marc Baldus
- Utrecht NMR Group, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH, Utrecht, the Netherlands
| | - Hugo van Ingen
- Utrecht NMR Group, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH, Utrecht, the Netherlands
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Vallet A, Favier A, Brutscher B, Schanda P. ssNMRlib: a comprehensive library and tool box for acquisition of solid-state nuclear magnetic resonance experiments on Bruker spectrometers. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2020; 1:331-345. [PMID: 37904819 PMCID: PMC10500710 DOI: 10.5194/mr-1-331-2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/16/2020] [Indexed: 11/01/2023]
Abstract
We introduce ssNMRlib, a comprehensive suite of pulse sequences and jython scripts for user-friendly solid-state nuclear magnetic resonance (NMR) data acquisition, parameter optimization and storage on Bruker spectrometers. ssNMRlib allows the straightforward setup of even highly complex multi-dimensional solid-state NMR experiments with a few clicks from an intuitive graphical interface directly from the Bruker Topspin acquisition software. ssNMRlib allows the setup of experiments in a magnetic-field-independent manner and thus facilitates the workflow in a multi-spectrometer setting with a centralized library. Safety checks furthermore assist the user in experiment setup. Currently hosting more than 140 1D to 4D experiments, primarily for biomolecular solid-state NMR, the library can be easily customized and new experiments are readily added as new templates. ssNMRlib is part of the previously introduced NMRlib library, which comprises many solution-NMR pulse sequences and macros.
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Affiliation(s)
- Alicia Vallet
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 71, Avenue des Martyrs, 38044 Grenoble, France
| | - Adrien Favier
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 71, Avenue des Martyrs, 38044 Grenoble, France
| | - Bernhard Brutscher
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 71, Avenue des Martyrs, 38044 Grenoble, France
| | - Paul Schanda
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 71, Avenue des Martyrs, 38044 Grenoble, France
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29
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Dynamic networks observed in the nucleosome core particles couple the histone globular domains with DNA. Commun Biol 2020; 3:639. [PMID: 33128005 PMCID: PMC7599221 DOI: 10.1038/s42003-020-01369-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022] Open
Abstract
The dynamics of eukaryotic nucleosomes are essential in gene activity and well regulated by various factors. Here, we elucidated the internal dynamics at multiple timescales for the human histones hH3 and hH4 in the Widom 601 nucleosome core particles (NCP), suggesting that four dynamic networks are formed by the residues exhibiting larger-scale μs-ms motions that extend from the NCP core to the histone tails and DNA. Furthermore, despite possessing highly conserved structural features, histones in the telomeric NCP exhibit enhanced μs-ms dynamics in the globular sites residing at the identified dynamic networks and in a neighboring region. In addition, higher mobility was observed for the N-terminal tails of hH3 and hH4 in the telomeric NCP. The results demonstrate the existence of dynamic networks in nucleosomes, through which the center of the core regions could interactively communicate with histone tails and DNA to potentially propagate epigenetic changes. Shi et al. use solid-state nuclear magnetic resonance spectroscopy to reveal the internal dynamics of human histones hH3 and hH4 in the Widom 601 and the telomeric nucleosome core particles. This work has implications for the propagation of epigenetic changes via the center of the nucleosome core communicating with histone tails and DNA.
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30
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Bendandi A, Patelli AS, Diaspro A, Rocchia W. The role of histone tails in nucleosome stability: An electrostatic perspective. Comput Struct Biotechnol J 2020; 18:2799-2809. [PMID: 33133421 PMCID: PMC7575852 DOI: 10.1016/j.csbj.2020.09.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/23/2020] [Accepted: 09/24/2020] [Indexed: 01/20/2023] Open
Abstract
We propose a methodology for the study of protein-DNA electrostatic interactions and apply it to clarify the effect of histone tails in nucleosomes. This method can be used to correlate electrostatic interactions to structural and functional features of protein-DNA systems, and can be combined with coarse-grained representations. In particular, we focus on the electrostatic field and resulting forces acting on the DNA. We investigate the electrostatic origins of effects such as different stages in DNA unwrapping, nucleosome destabilization upon histone tail truncation, and the role of specific arginines and lysines undergoing Post-Translational Modifications. We find that the positioning of the histone tails can oppose the attractive pull of the histone core, locally deform the DNA, and tune DNA unwrapping. Small conformational variations in the often overlooked H2A C-terminal tails had significant electrostatic repercussions near the DNA entry and exit sites. The H2A N-terminal tail exerts attractive electrostatic forces towards the histone core in positions where Polymerase II halts its progress. We validate our results with comparisons to previous experimental and computational observations.
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Affiliation(s)
- Artemi Bendandi
- DIFILAB, Department of Physics, University of Genoa, Via Dodecaneso 33, 16149 Genoa, Italy.,CHT Erzelli, Nanoscopy, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
| | - Alessandro S Patelli
- LCVMM, Institute of Mathematics, Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne, Switzerland
| | - Alberto Diaspro
- DIFILAB, Department of Physics, University of Genoa, Via Dodecaneso 33, 16149 Genoa, Italy.,CHT Erzelli, Nanoscopy, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
| | - Walter Rocchia
- Concept Lab, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
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31
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Strategies for identifying dynamic regions in protein complexes: Flexibility changes accompany methylation in chemotaxis receptor signaling states. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183312. [PMID: 32304758 DOI: 10.1016/j.bbamem.2020.183312] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/24/2020] [Accepted: 04/13/2020] [Indexed: 12/11/2022]
Abstract
Bacterial chemoreceptors are organized in arrays composed of helical receptors arranged as trimers of dimers, coupled to a histidine kinase CheA and a coupling protein CheW. Ligand binding to the external domain inhibits the kinase activity, leading to a change in the swimming behavior. Adaptation to an ongoing stimulus involves reversible methylation and demethylation of specific glutamate residues. However, the exact mechanism of signal propagation through the helical receptor to the histidine kinase remains elusive. Dynamics of the receptor cytoplasmic domain is thought to play an important role in the signal transduction, and current models propose inverse dynamic changes in different regions of the receptor. We hypothesize that the adaptational modification (methylation) controls the dynamics by stabilizing a partially ordered domain, which in turn modulates the binding of the kinase, CheA. We investigated the difference in dynamics between the methylated and unmethylated states of the chemoreceptor using solid-state NMR. The unmethylated receptor (CF4E) shows increased flexibility relative to the methylated mimic (CF4Q). Methylation helix 1 (MH1) has been shown to be flexible in the methylated mimic receptor. Our analysis indicates that in addition to MH1, methylation helix 2 also becomes flexible in the unmethylated receptor. In addition, we have demonstrated that both states of the receptor have a rigid region and segments with intermediate timescale dynamics. The strategies used in this study for identifying dynamic regions are applicable to a broad class of proteins and protein complexes with intrinsic disorder and dynamics spanning multiple timescales.
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32
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Shi X, Prasanna C, Pervushin K, Nordenskiöld L. Solid-state NMR 13C, 15N assignments of human histone H3 in the nucleosome core particle. BIOMOLECULAR NMR ASSIGNMENTS 2020; 14:99-104. [PMID: 31907727 DOI: 10.1007/s12104-020-09927-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/02/2020] [Indexed: 06/10/2023]
Abstract
Nucleosome core particle (NCP), the basic unit of chromatin in eukaryotic cells, consists of ~ 147 bp DNA wrapped around a histone octamer (HO) formed by two H2A-H2B dimers and one (H3-H4)2 tetramer. Histones undergo various post-translational modifications (PTMs), which regulates genomic activities in different cellular phases. High-resolution structures have been solved for many nucleosomes primarily including NCPs. However, the atomic-resolution structures of nucleosome arrays and chromatin fiber, as well as the dynamics of nucleosomes remain poorly understood. Solid-state NMR (SSNMR) is one of the premier techniques to answer these questions. In this study, we present the 13C and 15N chemical shifts assignments for the globular domain of human histone H3 (hH3) using multidimensional SSNMR experiments. The obtained spectra are of outstanding resolution and the assignments are nearly 100% complete for the backbone 13C and 15N spins of R42-G132 and ~ 80% when taking into account the side chains. The secondary structure derived from the chemical shifts agrees with the previously reported X-ray crystal structure. The reported chemical shifts can be carried over to future SSNMR studies of structure and dynamics of hH3 in NCPs, nucleosome array, chromatin fibers and nucleosome-protein complexes.
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Affiliation(s)
- Xiangyan Shi
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
| | - Chinmayi Prasanna
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
| | - Konstantin Pervushin
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
| | - Lars Nordenskiöld
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore.
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33
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Siemer AB. Advances in studying protein disorder with solid-state NMR. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2020; 106:101643. [PMID: 31972419 PMCID: PMC7202078 DOI: 10.1016/j.ssnmr.2020.101643] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/06/2020] [Accepted: 01/07/2020] [Indexed: 05/26/2023]
Abstract
Solution NMR is a key tool to study intrinsically disordered proteins (IDPs), whose importance for biological function is widely accepted. However, disordered proteins are not limited to solution and are also found in non-soluble systems such as fibrils and membrane proteins. In this Trends article, I will discuss how solid-state NMR can be used to study disorder in non-soluble proteins. Techniques based on dipolar couplings can study static protein disorder which either occurs naturally as e.g. in spider silk or can be induced by freeze trapping IDPs or unfolded proteins. In this case, structural ensembles are directly reflected by a static distribution of dihedral angels that can be determined by the distribution of chemical shifts or other methods. Techniques based on J-couplings can detect dynamic protein disorder under MAS. In this case, only average chemical shifts are measured but disorder can be characterized with a variety of data including secondary chemical shifts, relaxation rates, paramagnetic relaxation enhancements, or residual dipolar couplings. I describe both technical aspects and examples of solid-state NMR on protein disorder and end the article with a discussion of challenges and opportunities of this emerging field.
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Affiliation(s)
- Ansgar B Siemer
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Univeristy of Southern California, 1501 San Pablo Street, Los Angeles, CA, 90033, USA.
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34
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Bendandi A, Dante S, Zia SR, Diaspro A, Rocchia W. Chromatin Compaction Multiscale Modeling: A Complex Synergy Between Theory, Simulation, and Experiment. Front Mol Biosci 2020; 7:15. [PMID: 32158765 PMCID: PMC7051991 DOI: 10.3389/fmolb.2020.00015] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 01/27/2020] [Indexed: 12/24/2022] Open
Abstract
Understanding the mechanisms that trigger chromatin compaction, its patterns, and the factors they depend on, is a fundamental and still open question in Biology. Chromatin compacts and reinforces DNA and is a stable but dynamic structure, to make DNA accessible to proteins. In recent years, computational advances have provided larger amounts of data and have made large-scale simulations more viable. Experimental techniques for the extraction and reconstitution of chromatin fibers have improved, reinvigorating theoretical and experimental interest in the topic and stimulating debate on points previously considered as certainties regarding chromatin. A great assortment of approaches has emerged, from all-atom single-nucleosome or oligonucleosome simulations to various degrees of coarse graining, to polymer models, to fractal-like structures and purely topological models. Different fiber-start patterns have been studied in theory and experiment, as well as different linker DNA lengths. DNA is a highly charged macromolecule, making ionic and electrostatic interactions extremely important for chromatin topology and dynamics. Indeed, the repercussions of varying ionic concentration have been extensively examined at the computational level, using all-atom, coarse-grained, and continuum techniques. The presence of high-curvature AT-rich segments in DNA can cause conformational variations, attesting to the fact that the role of DNA is both structural and electrostatic. There have been some tentative attempts to describe the force fields governing chromatin conformational changes and the energy landscapes of these transitions, but the intricacy of the system has hampered reaching a consensus. The study of chromatin conformations is an intrinsically multiscale topic, influenced by a wide range of biological and physical interactions, spanning from the atomic to the chromosome level. Therefore, powerful modeling techniques and carefully planned experiments are required for an overview of the most relevant phenomena and interactions. The topic provides fertile ground for interdisciplinary studies featuring a synergy between theoretical and experimental scientists from different fields and the cross-validation of respective results, with a multi-scale perspective. Here, we summarize some of the most representative approaches, and focus on the importance of electrostatics and solvation, often overlooked aspects of chromatin modeling.
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Affiliation(s)
- Artemi Bendandi
- Physics Department, University of Genoa, Genoa, Italy
- Nanophysics & NIC@IIT, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Silvia Dante
- Nanophysics & NIC@IIT, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Syeda Rehana Zia
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Alberto Diaspro
- Physics Department, University of Genoa, Genoa, Italy
- Nanophysics & NIC@IIT, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Walter Rocchia
- Concept Lab, Istituto Italiano di Tecnologia, Genoa, Italy
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35
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Grigoryev SA, Popova EY. Attraction of Likenesses: Mechanisms of Self-Association and Compartmentalization of Eukaryotic Chromatin. Mol Biol 2019. [DOI: 10.1134/s0026893319060050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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36
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Papanastasiou M, Mullahoo J, DeRuff KC, Bajrami B, Karageorgos I, Johnston SE, Peckner R, Myers SA, Carr SA, Jaffe JD. Chasing Tails: Cathepsin-L Improves Structural Analysis of Histones by HX-MS. Mol Cell Proteomics 2019; 18:2089-2098. [PMID: 31409669 PMCID: PMC6773551 DOI: 10.1074/mcp.ra119.001325] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 07/19/2019] [Indexed: 12/27/2022] Open
Abstract
The N-terminal regions (tails) of histone proteins are dynamic elements that protrude from the nucleosome and are involved in many aspects of chromatin organization. Their epigenetic role is well-established, and post-translational modifications present on these regions contribute to transcriptional regulation. Considering their biological significance, relatively few structural details have been established for histone tails, mainly because of their inherently disordered nature. Although hydrogen/deuterium exchange mass spectrometry (HX-MS) is well-suited for the analysis of dynamic structures, it has seldom been employed in this context, presumably because of the poor N-terminal coverage provided by pepsin. Inspired from histone-clipping events, we profiled the activity of cathepsin-L under HX-MS quench conditions and characterized its specificity employing the four core histones (H2A, H2B, H3 and H4). Cathepsin-L demonstrated cleavage patterns that were substrate- and pH-dependent. Cathepsin-L generated overlapping N-terminal peptides about 20 amino acids long for H2A, H3, and H4 proving its suitability for the analysis of histone tails dynamics. We developed a comprehensive HX-MS method in combination with pepsin and obtained full sequence coverage for all histones. We employed our method to analyze histones H3 and H4. We observe rapid deuterium exchange of the N-terminal tails and cooperative unfolding (EX1 kinetics) in the histone-fold domains of histone monomers in-solution. Overall, this novel strategy opens new avenues for investigating the dynamic properties of histones that are not apparent from the crystal structures, providing insights into the structural basis of the histone code.
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Affiliation(s)
| | | | | | | | - Ioannis Karageorgos
- Biomolecular Measurements Division, National Institute of Standards and Technology, Gaithersburg, MD;; Institute for Bioscience and Biotechnology Research, Rockville, MD
| | | | - Ryan Peckner
- The Broad Institute of MIT and Harvard, Cambridge, MA
| | | | - Steven A Carr
- The Broad Institute of MIT and Harvard, Cambridge, MA
| | - Jacob D Jaffe
- The Broad Institute of MIT and Harvard, Cambridge, MA
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37
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Kashefi M, Malik N, Struppe JO, Thompson LK. Carbon-nitrogen REDOR to identify ms-timescale mobility in proteins. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 305:5-15. [PMID: 31158793 PMCID: PMC6656615 DOI: 10.1016/j.jmr.2019.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 05/21/2019] [Accepted: 05/22/2019] [Indexed: 06/09/2023]
Abstract
Protein dynamics play key mechanistic roles but are difficult to measure in large proteins and protein complexes. INEPT and CP solid-state NMR experiments have often been used to obtain spectra of protein regions that are mobile and rigid, respectively, on the nanosecond timescale. To complement this approach, we have implemented 13C{15N} REDOR to detect protein regions with backbone dynamics on the millisecond time scale that average the ≈1 kHz carbon-nitrogen dipolar coupling. REDOR-filtering of carbon correlation spectra removes signals from rigid backbone carbons and retains signals from backbone carbons with ms-timescale dynamics that would be missing in dipolar-driven NCA/NCO spectra. We use these experiments to investigate functionally important dynamics within the E coli Asp receptor cytoplasmic fragment (U-13C, 15N-CF) in native-like complexes with CheA and CheW. The CF backbone carbons exhibit only 60-75% of the expected REDOR dephasing, suggesting that 40-25% of the backbone experiences significant mobility that averages the 13C15N dipolar couplings to zero. Furthermore, the extent of this mobility changes with signaling state.
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Affiliation(s)
- Maryam Kashefi
- Department of Chemistry, University of Massachusetts Amherst, 710 N Pleasant St, Amherst, MA 01003, USA
| | - Nikita Malik
- Department of Chemistry, University of Massachusetts Amherst, 710 N Pleasant St, Amherst, MA 01003, USA
| | - Jochem O Struppe
- Bruker BioSpin Corporation, 15 Fortune Drive, Billerica, MA 01821, USA
| | - Lynmarie K Thompson
- Department of Chemistry, University of Massachusetts Amherst, 710 N Pleasant St, Amherst, MA 01003, USA.
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38
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Perez A, Gaalswyk K, Jaroniec CP, MacCallum JL. High Accuracy Protein Structures from Minimal Sparse Paramagnetic Solid‐State NMR Restraints. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201811895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Alberto Perez
- Department of Chemistry University of Florida Gainesville FL USA
| | - Kari Gaalswyk
- Department of Chemistry University of Calgary Calgary Alberta Canada
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39
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Abstract
Nucleosomes and chromatin control eukaryotic genome accessibility and thereby regulate DNA processes, including transcription, replication, and repair. Conformational dynamics within the nucleosome and chromatin structure play a key role in this regulatory function. Structural fluctuations continuously expose internal DNA sequences and nucleosome surfaces, thereby providing transient access for the nuclear machinery. Progress in structural studies of nucleosomes and chromatin has provided detailed insight into local chromatin organization and has set the stage for recent in-depth investigations of the structural dynamics of nucleosomes and chromatin fibers. Here, we discuss the dynamic processes observed in chromatin over different length scales and timescales and review current knowledge about the biophysics of distinct structural transitions.
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Affiliation(s)
- Beat Fierz
- Laboratory of Biophysical Chemistry of Macromolecules, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Michael G. Poirier
- Department of Physics, Biophysics Graduate Program, Ohio State Biochemistry Graduate Program, and Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210-1117, USA
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40
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Unraveling the multiplex folding of nucleosome chains in higher order chromatin. Essays Biochem 2019; 63:109-121. [PMID: 31015386 DOI: 10.1042/ebc20180066] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/25/2019] [Accepted: 03/01/2019] [Indexed: 12/19/2022]
Abstract
The DNA of eukaryotic chromatin and chromosomes is repeatedly supercoiled around histone octamers forming 'beads-on-a-string' chains of nucleosomes. The extent of nucleosome chain folding and DNA accessibility vary between different functional and epigenetic states of nuclear chromatin and change dramatically upon cell differentiation, but the molecular mechanisms that direct 3D folding of the nucleosome chain in vivo are still enigmatic. Recent advances in cell imaging and chromosome capture techniques have radically challenged the established paradigm of regular and hierarchical chromatin fibers by highlighting irregular chromatin organization and the importance of the nuclear skeletal structures hoisting the nucleosome chains. Here, we argue that, by analyzing individual structural elements of the nucleosome chain - nucleosome spacing, linker DNA conformations, internucleosomal interactions, and nucleosome chain flexibility - and integrating these elements in multiplex 3D structural models, we can predict the features of the multiplex chromatin folding assemblies underlying distinct developmental and epigenetic states in living cells. Furthermore, partial disassembly of the nuclear structures suspending chromatin fibers may reveal the intrinsic mechanisms of nucleosome chain folding. These mechanisms and structures are expected to provide molecular cues to modify chromatin structure and functions related to developmental and disease processes.
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41
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Musselman CA, Kutateladze TG. Strategies for Generating Modified Nucleosomes: Applications within Structural Biology Studies. ACS Chem Biol 2019; 14:579-586. [PMID: 30817115 DOI: 10.1021/acschembio.8b01049] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Post-translational modifications on histone proteins play critical roles in the regulation of chromatin structure and all DNA-templated processes. Accumulating evidence suggests that these covalent modifications can directly alter chromatin structure, or they can modulate activities of chromatin-modifying and -remodeling factors. Studying these modifications in the context of the nucleosome, the basic subunit of chromatin, is thus of great interest; however, the generation of specifically modified nucleosomes remains challenging. This is especially problematic for most structural biology approaches in which a large amount of material is often needed. Here we discuss the strategies currently available for generation of these substrates. We in particular focus on novel ideas and discuss challenges in the application to structural biology studies.
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Affiliation(s)
- Catherine A. Musselman
- Department of Biochemistry, University of Iowa Carver College of Medicine, Iowa City, Iowa 52246, United States
| | - Tatiana G. Kutateladze
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045, United States
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42
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Perez A, Gaalswyk K, Jaroniec CP, MacCallum JL. High Accuracy Protein Structures from Minimal Sparse Paramagnetic Solid-State NMR Restraints. Angew Chem Int Ed Engl 2019; 58:6564-6568. [PMID: 30913341 DOI: 10.1002/anie.201811895] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 02/01/2019] [Indexed: 11/08/2022]
Abstract
There is a pressing need for new computational tools to integrate data from diverse experimental approaches in structural biology. We present a strategy that combines sparse paramagnetic solid-state NMR restraints with physics-based atomistic simulations. Our approach explicitly accounts for uncertainty in the interpretation of experimental data through the use of a semi-quantitative mapping between the data and the restraint energy that is calibrated by extensive simulations. We apply our approach to solid-state NMR data for the model protein GB1 labeled with Cu2+ -EDTA at six different sites. We are able to determine the structure to 0.9 Å accuracy within a single day of computation on a GPU cluster. We further show that in some cases, the data from only a single paramagnetic tag are sufficient for accurate folding.
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Affiliation(s)
- Alberto Perez
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Kari Gaalswyk
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada
| | | | - Justin L MacCallum
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada
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43
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Shabane PS, Izadi S, Onufriev AV. General Purpose Water Model Can Improve Atomistic Simulations of Intrinsically Disordered Proteins. J Chem Theory Comput 2019; 15:2620-2634. [PMID: 30865832 DOI: 10.1021/acs.jctc.8b01123] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Unconstrained atomistic simulations of intrinsically disordered proteins and peptides (IDP) remain a challenge: widely used, "general purpose" water models tend to favor overly compact structures relative to experiment. Here we have performed a total of 93 μs of unrestrained MD simulations to explore, in the context of IDPs, a recently developed "general-purpose" 4-point rigid water model OPC, which describes liquid state of water close to experiment. We demonstrate that OPC, together with a popular AMBER force field ff99SB, offers a noticeable improvement over TIP3P in producing more realistic structural ensembles of three common IDPs benchmarks: 55-residue apo N-terminal zinc-binding domain of HIV-1 integrase ("protein IN"), amyloid β-peptide (Aβ42) (residues 1-42), and 26-reside H4 histone tail. As a negative control, computed folding profile of a regular globular miniprotein (CLN025) in OPC water is in appreciably better agreement with experiment than that obtained in TIP3P, which tends to overstabilize the compact native state relative to the extended conformations. We employed Aβ42 peptide to investigate the possible influence of the solvent box size on simulation outcomes. We advocate a cautious approach for simulations of IDPs: we suggest that the solvent box size should be at least four times the radius of gyration of the random coil corresponding to the IDP. The computed free energy landscape of protein IN in OPC resembles a shallow "tub" - conformations with substantially different degrees of compactness that are within 2 kB T of each other. Conformations with very different secondary structure content coexist within 1 kB T of the global free energy minimum. States with higher free energy tend to have less secondary structure. Computed low helical content of the protein has virtually no correlation with its degree of compactness, which calls into question the possibility of using the helicity as a metric for assessing performance of water models for IDPs, when the helicity is low. Predicted radius of gyration ( R g) of H4 histone tail in OPC water falls in-between that of a typical globular protein and a fully denatured protein of the same size; the predicted R g is consistent with two independent predictions. In contrast, H4 tail in TIP3P water is as compact as the corresponding globular protein. The computed free energy landscape of H4 tail in OPC is relatively flat over a significant range of compactness, which, we argue, is consistent with its biological function as facilitator of internucleosome interactions.
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Affiliation(s)
| | - Saeed Izadi
- Early Stage Pharmaceutical Development , Genentech Inc. , South San Francisco , California 94080 , United States
| | - Alexey V Onufriev
- Department of Computer Science , Virginia Tech , Blacksburg , Virginia 24060 , United States.,Center for Soft Matter and Biological Physics , Virginia Tech , Blacksburg , Virginia 24061 , United States
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44
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Moller J, Lequieu J, de Pablo JJ. The Free Energy Landscape of Internucleosome Interactions and Its Relation to Chromatin Fiber Structure. ACS CENTRAL SCIENCE 2019; 5:341-348. [PMID: 30834322 PMCID: PMC6396382 DOI: 10.1021/acscentsci.8b00836] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Indexed: 05/11/2023]
Abstract
The supramolecular chromatin fiber is governed by molecular scale energetics and interactions. Such energetics originate from the fiber's building block, the nucleosome core particle (NCP). In recent years, the chromatin fiber has been examined through perturbative methods in attempts to extract the energetics of nucleosome association in the fiber. This body of work has led to different results from experiments and simulations concerning the nucleosome-nucleosome energetics. Here, we expand on previous experiments and use coarse-grained simulations to evaluate the energetics inherent to nucleosomes across a variety of parameters in configurational and environmental space. Through this effort, we are able to uncover molecular processes that are critical to understanding the 30 nm chromatin fiber structure. In particular, we describe the NCP-NCP interactions by relying on an anisotropic energetic landscape, rather than a single potential energy value. The attractions in that landscape arise predominantly from the highly anisotropic interactions provided by the NCP histone N-terminal domain (NTD) tails. Our results are found to be in good agreement with recent nucleosome interaction experiments that suggest a maximum interaction energy of 2.69k B T. Furthermore, we examine the influence of crucial epigenetic modifications, such as acetylation of the H4 tail, and how they modify the underlying landscape. Our results for acetylated NCP interactions are also in agreement with experiment. We additionally find an induced chirality in NCP-NCP interactions upon acetylation that reduces interactions which would correspond to a left-handed superhelical chromatin fiber.
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Affiliation(s)
- Joshua Moller
- Institute
for Molecular Engineering, University of
Chicago, Chicago, Illinois 60637, United States
| | - Joshua Lequieu
- Institute
for Molecular Engineering, University of
Chicago, Chicago, Illinois 60637, United States
- Chemical
Engineering, University of California Santa
Barbara, Santa Barbara, California 93106, United States
| | - Juan J. de Pablo
- Institute
for Molecular Engineering, University of
Chicago, Chicago, Illinois 60637, United States
- Materials
Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
- E-mail for J.J.d.P.:
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45
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van Emmerik CL, van Ingen H. Unspinning chromatin: Revealing the dynamic nucleosome landscape by NMR. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2019; 110:1-19. [PMID: 30803691 DOI: 10.1016/j.pnmrs.2019.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/15/2019] [Accepted: 01/15/2019] [Indexed: 05/09/2023]
Abstract
NMR is an essential technique for obtaining information at atomic resolution on the structure, motions and interactions of biomolecules. Here, we review the contribution of NMR to our understanding of the fundamental unit of chromatin: the nucleosome. Nucleosomes compact the genome by wrapping the DNA around a protein core, the histone octamer, thereby protecting genomic integrity. Crucially, the imposed barrier also allows strict regulation of gene expression, DNA replication and DNA repair processes through an intricate system of histone and DNA modifications and a wide range of interactions between nucleosomes and chromatin factors. In this review, we describe how NMR has contributed to deciphering the molecular basis of nucleosome function. Starting from pioneering studies in the 1960s using natural abundance NMR studies, we focus on the progress in sample preparation and NMR methodology that has allowed high-resolution studies on the nucleosome and its subunits. We summarize the results and approaches of state-of-the-art NMR studies on nucleosomal DNA, histone complexes, nucleosomes and nucleosomal arrays. These studies highlight the particular strength of NMR in studying nucleosome dynamics and nucleosome-protein interactions. Finally, we look ahead to exciting new possibilities that will be afforded by on-going developments in solution and solid-state NMR. By increasing both the depth and breadth of nucleosome NMR studies, it will be possible to offer a unique perspective on the dynamic landscape of nucleosomes and its interacting proteins.
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Affiliation(s)
- Clara L van Emmerik
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, the Netherlands.
| | - Hugo van Ingen
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, the Netherlands.
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46
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Wu H, Wolynes PG, Papoian GA. AWSEM-IDP: A Coarse-Grained Force Field for Intrinsically Disordered Proteins. J Phys Chem B 2018; 122:11115-11125. [PMID: 30091924 PMCID: PMC6713210 DOI: 10.1021/acs.jpcb.8b05791] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The associative memory, water-mediated, structure and energy model (AWSEM) has been successfully used to study protein folding, binding, and aggregation problems. In this work, we introduce AWSEM-IDP, a new AWSEM branch for simulating intrinsically disordered proteins (IDPs), where the weights of the potentials determining secondary structure formation have been finely tuned, and a novel potential is introduced that helps to precisely control both the average extent of protein chain collapse and the chain's fluctuations in size. AWSEM-IDP can efficiently sample large conformational spaces, while retaining sufficient molecular accuracy to realistically model proteins. We applied this new model to two IDPs, demonstrating that AWSEM-IDP can reasonably well reproduce higher-resolution reference data, thus providing the foundation for a transferable IDP force field. Finally, we used thermodynamic perturbation theory to show that, in general, the conformational ensembles of IDPs are highly sensitive to fine-tuning of force field parameters.
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Affiliation(s)
- Hao Wu
- Biophysics Program, Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, United States
| | - Peter G. Wolynes
- Departments of Chemistry and Physics and Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States
| | - Garegin A. Papoian
- Biophysics Program, Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, United States
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
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47
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Zhou K, Gaullier G, Luger K. Nucleosome structure and dynamics are coming of age. Nat Struct Mol Biol 2018; 26:3-13. [PMID: 30532059 DOI: 10.1038/s41594-018-0166-x] [Citation(s) in RCA: 180] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/07/2018] [Indexed: 11/09/2022]
Abstract
Since the first high-resolution structure of the nucleosome was reported in 1997, the available information on chromatin structure has increased very rapidly. Here, we review insights derived from cutting-edge biophysical and structural approaches applied to the study of nucleosome dynamics and nucleosome-binding factors, with a focus on the experimental advances driving the research. In addition, we highlight emerging challenges in nucleosome structural biology.
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Affiliation(s)
- Keda Zhou
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Guillaume Gaullier
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA
| | - Karolin Luger
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA. .,Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA.
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48
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Chakraborty K, Kang M, Loverde SM. Molecular Mechanism for the Role of the H2A and H2B Histone Tails in Nucleosome Repositioning. J Phys Chem B 2018; 122:11827-11840. [DOI: 10.1021/acs.jpcb.8b07881] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kaushik Chakraborty
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New York 10314, United States
| | - Myungshim Kang
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New York 10314, United States
| | - Sharon M. Loverde
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New York 10314, United States
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49
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Kämpf K, Izmailov SA, Rabdano SO, Groves AT, Podkorytov IS, Skrynnikov NR. What Drives 15N Spin Relaxation in Disordered Proteins? Combined NMR/MD Study of the H4 Histone Tail. Biophys J 2018; 115:2348-2367. [PMID: 30527335 DOI: 10.1016/j.bpj.2018.11.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/07/2018] [Accepted: 11/12/2018] [Indexed: 12/26/2022] Open
Abstract
Backbone (15N) NMR relaxation is one of the main sources of information on dynamics of disordered proteins. Yet, we do not know very well what drives 15N relaxation in such systems, i.e., how different forms of motion contribute to the measurable relaxation rates. To address this problem, we have investigated, both experimentally and via molecular dynamics simulations, the dynamics of a 26-residue peptide imitating the N-terminal portion of the histone protein H4. One part of the peptide was found to be fully flexible, whereas the other part features some transient structure (a hairpin stabilized by hydrogen bonds). The following motional modes proved relevant for 15N relaxation. 1) Sub-picosecond librations attenuate relaxation rates according to S2 ∼0.85-0.90. 2) Axial peptide-plane fluctuations along a stretch of the peptide chain contribute to relaxation-active dynamics on a fast timescale (from tens to hundreds of picoseconds). 3) φ/ψ backbone jumps contribute to relaxation-active dynamics on both fast (from tens to hundreds of picoseconds) and slow (from hundreds of picoseconds to a nanosecond) timescales. The major contribution is from polyproline II (PPII) ↔ β transitions in the Ramachandran space; in the case of glycine residues, the major contribution is from PPII ↔ (β) ↔ rPPII transitions, in which rPPII is the mirror-image (right-handed) version of the PPII geometry, whereas β geometry plays the role of an intermediate state. 4) Reorientational motion of certain (sufficiently long-lived) elements of transient structure, i.e., rotational tumbling, contributes to slow relaxation-active dynamics on ∼1-ns timescale (however, it is difficult to isolate this contribution). In conclusion, recent advances in the area of force-field development have made it possible to obtain viable Molecular Dynamics models of protein disorder. After careful validation against the experimental relaxation data, these models can provide a valuable insight into mechanistic origins of spin relaxation in disordered peptides and proteins.
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Affiliation(s)
- Kerstin Kämpf
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Sergei A Izmailov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Sevastyan O Rabdano
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Adam T Groves
- Department of Chemistry, Purdue University, West Lafayette, Indiana
| | - Ivan S Podkorytov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Nikolai R Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia; Department of Chemistry, Purdue University, West Lafayette, Indiana.
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50
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Caulkins BG, Cervantes SA, Isas JM, Siemer AB. Dynamics of the Proline-Rich C-Terminus of Huntingtin Exon-1 Fibrils. J Phys Chem B 2018; 122:9507-9515. [PMID: 30252478 DOI: 10.1021/acs.jpcb.8b09213] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Intrinsically disordered protein domains not only are found in soluble proteins but also can be part of large protein complexes or protein aggregates. For example, several amyloid fibrils have intrinsically disordered domains framing a rigid β-sheet-rich core. These disordered domains can often be observed using solution NMR methods in combination with modest magic angle spinning and without perdeuteration. But how can these regions be detected using solution NMR methods when they are part of a fibril that is not tumbling isotropically in solution? Here we addressed this question by investigating the dynamic C-terminus of huntingtin exon-1 (HTTex1) fibrils that are important in Huntington's disease. We assigned the most dynamic regions of the C-terminus of three HTTex1 variants. On the basis of this assignment, we measured site-specific secondary chemical shifts, peak intensities, and R1, R'2, and R1ρ 15N relaxation rates. In addition, we determined the residual 1H-15N dipolar couplings of this region. Our results show that the dipolar couplings are averaged to a very high degree, resulting in an order parameter that is essentially zero. Together, our data show that the C-terminus of HTTex1 is intrinsically disordered and undergoes motions in the high picosecond to low nanosecond range.
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Affiliation(s)
- Bethany G Caulkins
- Department of Physiology & Neuroscience, Zilkha Neurogenetic Institute , Keck School of Medicine of USC , 1501 San Pablo St. , Los Angeles , California 90033 , United States
| | - Silvia A Cervantes
- Department of Physiology & Neuroscience, Zilkha Neurogenetic Institute , Keck School of Medicine of USC , 1501 San Pablo St. , Los Angeles , California 90033 , United States
| | - J Mario Isas
- Department of Physiology & Neuroscience, Zilkha Neurogenetic Institute , Keck School of Medicine of USC , 1501 San Pablo St. , Los Angeles , California 90033 , United States
| | - Ansgar B Siemer
- Department of Physiology & Neuroscience, Zilkha Neurogenetic Institute , Keck School of Medicine of USC , 1501 San Pablo St. , Los Angeles , California 90033 , United States
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