1
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Patel R, Onyema A, Tang PK, Loverde SM. Conformational Dynamics of the Nucleosomal Histone H2B Tails Revealed by Molecular Dynamics Simulations. J Chem Inf Model 2024; 64:4709-4726. [PMID: 38865599 PMCID: PMC11200259 DOI: 10.1021/acs.jcim.4c00059] [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: 01/11/2024] [Revised: 05/31/2024] [Accepted: 06/03/2024] [Indexed: 06/14/2024]
Abstract
Epigenetic modifications of histone N-terminal tails play a critical role in regulating the chromatin structure and biological processes such as transcription and DNA repair. One of the key post-translational modifications (PTMs) is the acetylation of lysine residues on histone tails. Epigenetic modifications are ubiquitous in the development of diseases, such as cancer and neurological disorders. Histone H2B tails are critical regulators of nucleosome dynamics, biological processes, and certain diseases. Here, we report all-atomistic molecular dynamics (MD) simulations of the nucleosome to demonstrate that acetylation of the histone tails changes their conformational space and interaction with DNA. We perform simulations of H2B tails, critical regulators of gene regulation, in both the lysine-acetylated (ACK) and unacetylated wild type (WT) states. To explore the effects of salt concentration, we use two different NaCl concentrations to perform simulations at microsecond time scales. Salt can modulate the effects of electrostatic interactions between the DNA phosphate backbone and histone tails. Upon acetylation, H2B tails shift their secondary structure helical propensity. The number of contacts between the DNA and the H2B tail decreases. We characterize the conformational dynamics of the H2B tails by principal component analysis (PCA). The ACK tails become more compact at increased salt concentrations, but conformations from the WT tails display the most contacts with DNA at both salt concentrations. Mainly, H2B acetylation may increase the DNA accessibility for regulatory proteins to bind, which can aid in gene regulation and NCP stability.
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Affiliation(s)
- Rutika Patel
- Ph.D.
Program in Biochemistry, The Graduate Center
of the City University of New York, New York, New York 10016, United States
- Department
of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New
York, New York 10314, United States
| | - Augustine Onyema
- Ph.D.
Program in Biochemistry, The Graduate Center
of the City University of New York, New York, New York 10016, United States
- Department
of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New
York, New York 10314, United States
| | - Phu K. Tang
- Ph.D.
Program in Biochemistry, The Graduate Center
of the City University of New York, New York, New York 10016, United States
- Department
of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New
York, New York 10314, United States
| | - Sharon M. Loverde
- Ph.D.
Program in Biochemistry, The Graduate Center
of the City University of New York, New York, New York 10016, United States
- Department
of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New
York, New York 10314, United States
- Ph.D.
Program in Chemistry, The Graduate Center
of the City University of New York, New York, New York 10016, United States
- Ph.D.
Program in Physics, The Graduate Center
of the City University of New York, New York, New York 10016, United States
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2
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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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3
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Shvedunova M, Akhtar A. Modulation of cellular processes by histone and non-histone protein acetylation. Nat Rev Mol Cell Biol 2022; 23:329-349. [PMID: 35042977 DOI: 10.1038/s41580-021-00441-y] [Citation(s) in RCA: 253] [Impact Index Per Article: 126.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2021] [Indexed: 12/12/2022]
Abstract
Lysine acetylation is a widespread and versatile protein post-translational modification. Lysine acetyltransferases and lysine deacetylases catalyse the addition or removal, respectively, of acetyl groups at both histone and non-histone targets. In this Review, we discuss several features of acetylation and deacetylation, including their diversity of targets, rapid turnover, exquisite sensitivity to the concentrations of the cofactors acetyl-CoA, acyl-CoA and NAD+, and tight interplay with metabolism. Histone acetylation and non-histone protein acetylation influence a myriad of cellular and physiological processes, including transcription, phase separation, autophagy, mitosis, differentiation and neural function. The activity of lysine acetyltransferases and lysine deacetylases can, in turn, be regulated by metabolic states, diet and specific small molecules. Histone acetylation has also recently been shown to mediate cellular memory. These features enable acetylation to integrate the cellular state with transcriptional output and cell-fate decisions.
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Affiliation(s)
- Maria Shvedunova
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Asifa Akhtar
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany.
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4
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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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5
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Saurabh S, Jang YH, Lansac Y, Maiti PK. Orientation Dependence of Inter-NCP Interaction: Insights into the Behavior of Liquid Crystal Phase and Chromatin Fiber Organization. J Phys Chem B 2019; 124:314-323. [DOI: 10.1021/acs.jpcb.9b07898] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Suman Saurabh
- GREMAN, University of Tours, CNRS UMR 7347, 37200 Tours, France
- Centre de Biophysique Moléculaire, CNRS, Rue Charles Sadron, 45071 Orléans, France
| | - Yun Hee Jang
- Department of Energy Science and Engineering, DGIST, Daegu 42988, Korea
| | - Yves Lansac
- GREMAN, University of Tours, CNRS UMR 7347, 37200 Tours, France
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris Saclay, 91405 Orsay cedex, France
| | - Prabal K. Maiti
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
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6
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Structural Alterations of Histone Proteins in DNA-Damaged Cells Revealed by Synchrotron Radiation Circular Dichroism Spectroscopy: A New Piece of the DNA-Damage-Response Puzzle. QUANTUM BEAM SCIENCE 2019. [DOI: 10.3390/qubs3040023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Double-strand breaks of DNA may lead to discontinuous DNA and consequent loss of genetic information, which may result in mutations or, ultimately, carcinogenesis. To avoid such potentially serious situations, cells have evolved efficient DNA damage repair systems. It is thought that DNA-repair processes involve drastic alterations of chromatin and histone structures, but detection of these altered structures in DNA-damaged cells remains rare in the literature. Recently, synchrotron radiation circular dichroism (SRCD) spectroscopy, which can provide secondary structural information of proteins in solution, has identified structural alterations of histone proteins induced by DNA damage responses. In this review, these results and experimental procedures are discussed with the aim of facilitating further studies of the chromatin remodeling and DNA damage repair pathways using SRCD spectroscopy.
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7
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Urdinguio RG, Lopez V, Bayón GF, Diaz de la Guardia R, Sierra MI, García-Toraño E, Perez RF, García MG, Carella A, Pruneda PC, Prieto C, Dmitrijeva M, Santamarina P, Belmonte T, Mangas C, Diaconu E, Ferrero C, Tejedor JR, Fernandez-Morera JL, Bravo C, Bueno C, Sanjuan-Pla A, Rodriguez RM, Suarez-Alvarez B, López-Larrea C, Bernal T, Colado E, Balbín M, García-Suarez O, Chiara MD, Sáenz-de-Santa-María I, Rodríguez F, Pando-Sandoval A, Rodrigo L, Santos L, Salas A, Vallejo-Díaz J, C Carrera A, Rico D, Hernández-López I, Vayá A, Ricart JM, Seto E, Sima-Teruel N, Vaquero A, Valledor L, Cañal MJ, Pisano D, Graña-Castro O, Thomas T, Voss AK, Menéndez P, Villar-Garea A, Deutzmann R, Fernandez AF, Fraga MF. Chromatin regulation by Histone H4 acetylation at Lysine 16 during cell death and differentiation in the myeloid compartment. Nucleic Acids Res 2019; 47:5016-5037. [PMID: 30923829 PMCID: PMC6547425 DOI: 10.1093/nar/gkz195] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 02/26/2019] [Accepted: 03/15/2019] [Indexed: 12/14/2022] Open
Abstract
Histone H4 acetylation at Lysine 16 (H4K16ac) is a key epigenetic mark involved in gene regulation, DNA repair and chromatin remodeling, and though it is known to be essential for embryonic development, its role during adult life is still poorly understood. Here we show that this lysine is massively hyperacetylated in peripheral neutrophils. Genome-wide mapping of H4K16ac in terminally differentiated blood cells, along with functional experiments, supported a role for this histone post-translational modification in the regulation of cell differentiation and apoptosis in the hematopoietic system. Furthermore, in neutrophils, H4K16ac was enriched at specific DNA repeats. These DNA regions presented an accessible chromatin conformation and were associated with the cleavage sites that generate the 50 kb DNA fragments during the first stages of programmed cell death. Our results thus suggest that H4K16ac plays a dual role in myeloid cells as it not only regulates differentiation and apoptosis, but it also exhibits a non-canonical structural role in poising chromatin for cleavage at an early stage of neutrophil cell death.
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Affiliation(s)
- Rocio G Urdinguio
- Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Universidad de Oviedo-Principado de Asturias, Spain.,Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Virginia Lopez
- Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Universidad de Oviedo-Principado de Asturias, Spain
| | - Gustavo F Bayón
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Rafael Diaz de la Guardia
- Josep Carreras Leukemia Research Institute and Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red en Cáncer (CIBER-ONC), Barcelona, Spain
| | - Marta I Sierra
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Estela García-Toraño
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Raúl F Perez
- Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Universidad de Oviedo-Principado de Asturias, Spain.,Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - María G García
- Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Universidad de Oviedo-Principado de Asturias, Spain.,Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Antonella Carella
- Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Universidad de Oviedo-Principado de Asturias, Spain.,Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Patricia C Pruneda
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Cristina Prieto
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Marija Dmitrijeva
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Pablo Santamarina
- Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Universidad de Oviedo-Principado de Asturias, Spain.,Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Thalía Belmonte
- Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Universidad de Oviedo-Principado de Asturias, Spain.,Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Cristina Mangas
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Elena Diaconu
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Cecilia Ferrero
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Juan Ramón Tejedor
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Juan Luis Fernandez-Morera
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Cristina Bravo
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Clara Bueno
- Josep Carreras Leukemia Research Institute and Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red en Cáncer (CIBER-ONC), Barcelona, Spain
| | - Alejandra Sanjuan-Pla
- Hematology Research Group, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Valencia, 46026, Spain
| | - Ramon M Rodriguez
- Translational Immunology Laboratory, Instituto de Investigación Sanitarias del Principado de Asturias (ISPA), Immunology Department, Hospital Universitario Central de Asturias (HUCA), Oviedo, Spain
| | - Beatriz Suarez-Alvarez
- Translational Immunology Laboratory, Instituto de Investigación Sanitarias del Principado de Asturias (ISPA), Immunology Department, Hospital Universitario Central de Asturias (HUCA), Oviedo, Spain
| | - Carlos López-Larrea
- Translational Immunology Laboratory, Instituto de Investigación Sanitarias del Principado de Asturias (ISPA), Immunology Department, Hospital Universitario Central de Asturias (HUCA), Oviedo, Spain
| | - Teresa Bernal
- Servicio de Hematología, Hospital Universitario Central de Asturias (HUCA), Oviedo, Spain
| | - Enrique Colado
- Servicio de Hematología, Hospital Universitario Central de Asturias (HUCA), Oviedo, Spain
| | - Milagros Balbín
- Service of Molecular Oncology, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, Oviedo, Spain
| | - Olivia García-Suarez
- Department of Morphology and Cellular Biology, Faculty of Medicine, University of Oviedo, Oviedo, Spain
| | - María Dolores Chiara
- Otorhinolaryngology Service, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, CIBERONC, Oviedo, Spain
| | - Inés Sáenz-de-Santa-María
- Otorhinolaryngology Service, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, CIBERONC, Oviedo, Spain
| | - Francisco Rodríguez
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Oncología (IUOPA), Universidad de Oviedo, Oviedo, Spain
| | - Ana Pando-Sandoval
- Hospital Universitario Central de Asturias (HUCA), Instituto Nacional de Silicosis (INS), Área del Pulmón, Facultad de Medicina, Universidad de Oviedo, Avenida Roma s/n, Oviedo, Asturias 33011, Spain
| | - Luis Rodrigo
- Hospital Universitario Central de Asturias (HUCA), Gastroenterology Service, Facultad de Medicina, Universidad de Oviedo, Avenida de Roma s/n, Oviedo, Asturias 33011, Spain
| | - Laura Santos
- Fundación para la Investigación Biosanitaria de Asturias (FINBA). Instituto de Investigación Sanitaria del Principado de Asturias (ISPA). Avenida de Roma s/n, 33011 Oviedo. Asturias. España
| | - Ana Salas
- Cytometry Service, Servicios Científico-Técnicos (SCTs). Universidad de Oviedo, Oviedo, Spain
| | - Jesús Vallejo-Díaz
- Department of Immunology and Oncology, National Center for Biotechnology, CNB-CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Ana C Carrera
- Department of Immunology and Oncology, National Center for Biotechnology, CNB-CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Daniel Rico
- Institute of Cellular Medicine, Newcastle University, UK
| | | | - Amparo Vayá
- Hemorheology and Haemostasis Unit, Service of Clinical Pathology, La Fe University Hospital, Valencia, Spain
| | | | - Edward Seto
- George Washington University Cancer Center, Department of Biochemistry and Molecular Medicine, George Washington University, Washington, DC 20037, USA
| | - Núria Sima-Teruel
- Chromatin Biology Laboratory, Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Av. Gran Via de l'Hospitalet, 199-203, 08907- L'Hospitalet de Llobregat, Barcelona, Spain
| | - Alejandro Vaquero
- Chromatin Biology Laboratory, Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Av. Gran Via de l'Hospitalet, 199-203, 08907- L'Hospitalet de Llobregat, Barcelona, Spain
| | - Luis Valledor
- Plant Physiology Lab, Department of Organisms and Systems Biology, Faculty of Biology, University of Oviedo, Oviedo, Asturias, Spain
| | - Maria Jesus Cañal
- Plant Physiology Lab, Department of Organisms and Systems Biology, Faculty of Biology, University of Oviedo, Oviedo, Asturias, Spain
| | - David Pisano
- Bioinformatics Unit, Structural Biology and Biocomputing Program, Spanish National Cancer Research Center (CNIO), C/ Melchor Fernández Almagro, 3. 28029 Madrid, Spain
| | - Osvaldo Graña-Castro
- Bioinformatics Unit, Structural Biology and Biocomputing Program, Spanish National Cancer Research Center (CNIO), C/ Melchor Fernández Almagro, 3. 28029 Madrid, Spain
| | - Tim Thomas
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Anne K Voss
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Pablo Menéndez
- Josep Carreras Leukemia Research Institute and Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red en Cáncer (CIBER-ONC), Barcelona, Spain.,Instituciò Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Ana Villar-Garea
- Institute of Biochemistry, Genetics and Microbiology, University of Regensburg, 93053 Regensburg, Germany
| | - Rainer Deutzmann
- Institute of Biochemistry, Genetics and Microbiology, University of Regensburg, 93053 Regensburg, Germany
| | - Agustín F Fernandez
- Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), ISPA-Hospital Universitario Central de Asturias HUCA, Universidad de Oviedo, Oviedo, Spain
| | - Mario F Fraga
- Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Universidad de Oviedo-Principado de Asturias, Spain
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8
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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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9
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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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10
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Izumi Y, Matsuo K. Sample Volume Reduction Using the Schwarzschild Objective for a Circular Dichroism Spectrophotometer and an Application to the Structural Analysis of Lysine-36 Trimethylated Histone H3 Protein. Molecules 2018; 23:E2865. [PMID: 30400257 PMCID: PMC6278440 DOI: 10.3390/molecules23112865] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/31/2018] [Accepted: 11/01/2018] [Indexed: 11/28/2022] Open
Abstract
With the increasing interest in scarce proteins, reducing the sample volume for circular dichroism (CD) spectroscopy has become desirable. Demagnification of the incident beam size is required to reduce the sample volume for CD spectroscopy detecting transmitted light passed through the sample. In this study, the beam size was demagnified using a focal mirror, and small-capacity sample cells were developed in an attempt to reduce the sample volume. The original beam size was 6 × 6 mm²; we successfully converged it to a size of 25 × 25 μm² using the Schwarzschild objective (SO). The new sample cell and SO allowed the required sample volume to be reduced to 1/10 (15 → 1.5 μL), when using a 15 μm path length cell. By adopting a smaller sample cell, further sample reduction could be achieved. By using the SO system, the secondary structural contents of the lysine-36 trimethylated histone H3 protein were analyzed. The trimethylation induced the increment of helix structures and decrement of unordered structures. These structural alterations may play a role in regulating cellular function(s), such as DNA damage repair processes.
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Affiliation(s)
- Yudai Izumi
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
| | - Koichi Matsuo
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
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11
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Chen W, Liu Y, Zhu S, Chen G, Han JDJ. Inter-nucleosomal communication between histone modifications for nucleosome phasing. PLoS Comput Biol 2018; 14:e1006416. [PMID: 30188887 PMCID: PMC6126837 DOI: 10.1371/journal.pcbi.1006416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 08/02/2018] [Indexed: 11/20/2022] Open
Abstract
Combinatorial effects of epigenetic modifications on transcription activity have been proposed as “histone codes”. However, it is unclear whether there also exist inter-nucleosomal communications among epigenetic modifications at single nucleosome level, and if so, what functional roles they play. Meanwhile, how clear nucleosome patterns, such as nucleosome phasing and depletion, are formed at functional regions remains an intriguing enigma. To address these questions, we developed a Bayesian network model for interactions among different histone modifications across neighboring nucleosomes, based on the framework of dynamic Bayesian network (DBN). From this model, we found that robust inter-nucleosomal interactions exist around transcription start site (TSS), transcription termination sites (TTS) or around CTCF binding sites; and these inter-nucleosomal interactions are often involved in transcription regulation. In addition to these general principles, DBN also uncovered a novel specific epigenetic interaction between H2A.Z and H4K20me1 on neighboring nucleosomes, involved in nucleosome free region (NFR) and nucleosome phasing establishment or maintenance. The level of negative correlation between neighboring H2A.Z and H4K20me1 strongly correlate with the size of NFR and the strength of nucleosome phasing around TSS. Our study revealed inter-nucleosomal communications as important players in signal propagation, chromatin remodeling and transcription regulation. Nucleosomes are the basic unit of chromatin organization. At a global level, they fold up to form chromatin fibers in higher order structure to control the activation/repression states of chromatins. At a local level, especially around transcriptional starting sites (TSSs), nucleosomes play an important role in regulating gene expression by dynamically positioning to affect the recruitment of RNA polymerase II and transcriptional factors. In particular around actively transcribed TSSs, nucleosomes are regularly positioned to form a typical pattern of nucleosome phasing. As it suggests that the forming of nucleosome phasing is a synergistic behavior across the nucleosomes around TSS, we hypothesize that there exist communications, which is probably some propagations of histone modifications, between neighboring nucleosomes, as nucleosome functions are essentially due to histone modifications. Here, to address the question, we investigated the correlations of histone modifications across neighboring nucleosomes, and revealed a negative correlation between H2A.Z and H4K20me1 across neighboring nucleosomes. It is a development to the well accepted knowledge that H2A.Z and H4K20me1 are positively correlated at genome-wide level. In addition, we revealed a probable contribution of H2A.Z-H4K20me1 anti-correlation in nucleosome phasing around active TSSs, therefore, shedding light on understanding the forming of nucleosome phasing.
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Affiliation(s)
- Weizhong Chen
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yi Liu
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
- Beijing Key Lab of Traffic Data Analysis and Mining, School of Computer and Information Technology, Beijing Jiaotong University, Beijing, China
| | - Shanshan Zhu
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Guoyu Chen
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jing-Dong J. Han
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
- * E-mail:
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12
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Amamoto Y, Aoi Y, Nagashima N, Suto H, Yoshidome D, Arimura Y, Osakabe A, Kato D, Kurumizaka H, Kawashima SA, Yamatsugu K, Kanai M. Synthetic Posttranslational Modifications: Chemical Catalyst-Driven Regioselective Histone Acylation of Native Chromatin. J Am Chem Soc 2017; 139:7568-7576. [DOI: 10.1021/jacs.7b02138] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Yoshifumi Amamoto
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- JST-ERATO, Kanai Life Science Catalysis Project, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuki Aoi
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- JST-ERATO, Kanai Life Science Catalysis Project, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Nozomu Nagashima
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroki Suto
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- JST-ERATO, Kanai Life Science Catalysis Project, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Daisuke Yoshidome
- Schrödinger K. K., 17F Marunouchi
Trust Tower North, 1-8-1 Marunouchi Chiyoda-ku, Tokyo 100-0005, Japan
| | - Yasuhiro Arimura
- Laboratory
of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku,
Tokyo 162-8480, Japan
| | - Akihisa Osakabe
- Laboratory
of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku,
Tokyo 162-8480, Japan
| | - Daiki Kato
- Laboratory
of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku,
Tokyo 162-8480, Japan
| | - Hitoshi Kurumizaka
- Laboratory
of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku,
Tokyo 162-8480, Japan
| | - Shigehiro A. Kawashima
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- JST-ERATO, Kanai Life Science Catalysis Project, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kenzo Yamatsugu
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- JST-ERATO, Kanai Life Science Catalysis Project, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Motomu Kanai
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- JST-ERATO, Kanai Life Science Catalysis Project, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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13
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du Preez LL, Patterton HG. The effect of epigenetic modifications on the secondary structures and possible binding positions of the N-terminal tail of histone H3 in the nucleosome: a computational study. J Mol Model 2017; 23:137. [PMID: 28353152 PMCID: PMC5391383 DOI: 10.1007/s00894-017-3308-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 03/06/2017] [Indexed: 11/05/2022]
Abstract
The roles of histone tails as substrates for reversible chemical modifications and dynamic cognate surfaces for the binding of regulatory proteins are well established. Despite these crucial roles, experimentally derived knowledge of the structure and possible binding sites of histone tails in chromatin is limited. In this study, we utilized molecular dynamics of isolated histone H3 N-terminal peptides to investigate its structure as a function of post-translational modifications that are known to be associated with defined chromatin states. We observed a structural preference for α-helices in isoforms associated with an inactive chromatin state, while isoforms associated with active chromatin states lacked α-helical content. The physicochemical effect of the post-translational modifications was highlighted by the interaction of arginine side-chains with the phosphorylated serine residues in the inactive isoform. We also showed that the isoforms exhibit different tail lengths, and, using molecular docking of the first 15 N-terminal residues of an H3 isoform, identified potential binding sites between the superhelical gyres on the octamer surface, close to the site of DNA entry/exit in the nucleosome. We discuss the possible functional role of the binding of the H3 tail within the nucleosome on both nucleosome and chromatin structure and stability.
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Affiliation(s)
- Louis L du Preez
- Department of Microbiological, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, 9301, South Africa
| | - Hugh-G Patterton
- Division of Bioinformatics and Department of Biochemistry, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
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14
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Fu I, Cai Y, Geacintov NE, Zhang Y, Broyde S. Nucleosome Histone Tail Conformation and Dynamics: Impacts of Lysine Acetylation and a Nearby Minor Groove Benzo[a]pyrene-Derived Lesion. Biochemistry 2017; 56:1963-1973. [PMID: 28304160 DOI: 10.1021/acs.biochem.6b01208] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Histone tails in nucleosomes play critical roles in regulation of many biological processes, including chromatin compaction, transcription, and DNA repair. Moreover, post-translational modifications, notably lysine acetylation, are crucial to these functions. While the tails have been intensively studied, how the structures and dynamics of tails are impacted by the presence of a nearby bulky DNA lesion is a frontier research area, and how these properties are impacted by tail lysine acetylation remains unexplored. To obtain molecular insight, we have utilized all atom 3 μs molecular dynamics simulations of nucleosome core particles (NCPs) to determine the impact of a nearby DNA lesion, 10S (+)-trans-anti-B[a]P-N2-dG-the major adduct derived from the procarcinogen benzo[a]pyrene-on H2B tail behavior in unacetylated and acetylated states. We similarly studied lesion-free NCPs to investigate the normal properties of the H2B tail in both states. In the lesion-free NCPs, charge neutralization upon lysine acetylation causes release of the tail from the DNA. When the lesion is present, it stably engulfs part of the nearby tail, impairing the interactions between DNA and tail. With the tail in an acetylated state, the lesion still interacts with part of it, although unstably. The lesion's partial entrapment of the tail should hinder the tail from interacting with other nucleosomes, and other proteins such as acetylases, deacetylases, and acetyl-lysine binding proteins, and thus disrupt critical tail-governed processes. Hence, the lesion would impede tail functions modulated by acetylation or deacetylation, causing aberrant chromatin structures and impaired biological transactions such as transcription and DNA repair.
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Affiliation(s)
| | | | | | - Yingkai Zhang
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai , Shanghai 200062, China
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15
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Chen Q, Yang R, Korolev N, Liu CF, Nordenskiöld L. Regulation of Nucleosome Stacking and Chromatin Compaction by the Histone H4 N-Terminal Tail-H2A Acidic Patch Interaction. J Mol Biol 2017; 429:2075-2092. [PMID: 28322915 DOI: 10.1016/j.jmb.2017.03.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/13/2017] [Accepted: 03/13/2017] [Indexed: 01/15/2023]
Abstract
Chromatin folding and dynamics are critically dependent on nucleosome-nucleosome interactions with important contributions from internucleosome binding of the histone H4 N-terminal tail K16-R23 domain to the surface of the H2A/H2B dimer. The H4 Lys16 plays a pivotal role in this regard. Using in vitro reconstituted 12-mer nucleosome arrays, we have investigated the mechanism of the H4 N-terminal tail in maintaining nucleosome-nucleosome stacking and mediating intra- and inter-array chromatin compaction, with emphasis on the role of K16 and the positive charge region, R17-R23. Analytical ultracentrifugation sedimentation velocity experiments and precipitation assays were employed to analyze effects on chromatin folding and self-association, respectively. Effects on chromatin folding caused by various mutations and modifications at position K16 in the H4 histone were studied. Additionally, using charge-quenching mutations, we characterized the importance of the interaction of the residues within the H4 positive charge region R17-R23 with the H2A acidic patch of the adjacent nucleosome. Furthermore, crosslinking experiments were conducted to establish the proximity of the basic tail region to the acidic patch. Our data indicate that the positive charge and length of the side chain of H4 K16 are important for its access to the adjacent nucleosome in the process of nucleosome-nucleosome stacking and array folding. The location and orientation of the H4 R17-R23 domain on the H2A/H2B dimer surface of the neighboring nucleosome core particle (NCP) in the compacted chromatin fiber were established. The dominance of electrostatic interactions in maintaining intra-array interaction was demonstrated.
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Affiliation(s)
- Qinming Chen
- School of Biological Sciences, College of Science, Nanyang Technological University, 60, Nanyang Drive, 637551, Singapore
| | - Renliang Yang
- School of Biological Sciences, College of Science, Nanyang Technological University, 60, Nanyang Drive, 637551, Singapore
| | - Nikolay Korolev
- School of Biological Sciences, College of Science, Nanyang Technological University, 60, Nanyang Drive, 637551, Singapore
| | - Chuan Fa Liu
- School of Biological Sciences, College of Science, Nanyang Technological University, 60, Nanyang Drive, 637551, Singapore
| | - Lars Nordenskiöld
- School of Biological Sciences, College of Science, Nanyang Technological University, 60, Nanyang Drive, 637551, Singapore.
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16
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Zhang R, Erler J, Langowski J. Histone Acetylation Regulates Chromatin Accessibility: Role of H4K16 in Inter-nucleosome Interaction. Biophys J 2017; 112:450-459. [PMID: 27931745 PMCID: PMC5300776 DOI: 10.1016/j.bpj.2016.11.015] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/30/2016] [Accepted: 11/14/2016] [Indexed: 12/17/2022] Open
Abstract
The N-terminal tail of histone H4 is an indispensable mediator for inter-nucleosome interaction, which is required for chromatin fiber condensation. H4K16 acetylation (H4K16Ac) activates gene transcription by influencing both chromatin structure and interplay with nonhistone proteins. To understand the influence of H4K16Ac on inter-nucleosome interaction, we performed a simulation study for the H4 tail in the context of two nucleosomes in neighboring unit cells in the crystal structure. The binding conformation of H4 tail with/without K16Ac was sampled by replica exchange with solute tempering, and the free energy landscape was explored by metadynamics. The results indicate two important features of H4K16: 1) it is the first button to anchor the H4 tail on the adjacent nucleosome; and 2) it is the only acetylation site interacting with the acidic patch. H4K16Ac disrupts the electrostatic interactions of K16, weakens H4 tail-acidic patch binding, and significantly increases H4 tail conformation diversity. Our study suggests that H4K16Ac directly reduces the inter-nucleosome interaction mediated by the H4 tail, which might further encourage the binding of nonhistone proteins on the acidic patch.
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Affiliation(s)
- Ruihan Zhang
- Division Biophysics of Macromolecules, German Cancer Research Center, Heidelberg, Germany
| | - Jochen Erler
- Division Biophysics of Macromolecules, German Cancer Research Center, Heidelberg, Germany
| | - Jörg Langowski
- Division Biophysics of Macromolecules, German Cancer Research Center, Heidelberg, Germany.
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17
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Rajagopalan M, Balasubramanian S, Ioshikhes I, Ramaswamy A. Structural dynamics of nucleosome mediated by acetylations at H3K56 and H3K115,122. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2016; 46:471-484. [DOI: 10.1007/s00249-016-1191-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 11/03/2016] [Accepted: 11/28/2016] [Indexed: 12/15/2022]
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18
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Wang Q, Zheng QC, Zhang HX. Exploring the mechanism how AF9 recognizes and binds H3K9ac by molecular dynamics simulations and free energy calculations. Biopolymers 2016; 105:779-86. [DOI: 10.1002/bip.22896] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 06/01/2016] [Accepted: 06/10/2016] [Indexed: 12/12/2022]
Affiliation(s)
- Quan Wang
- Laboratory of Theoretical and Computational Chemistry; Institute of Theoretical Chemistry, Jilin University; Changchun 130023 People's Republic of China
| | - Qing-Chuan Zheng
- Laboratory of Theoretical and Computational Chemistry; Institute of Theoretical Chemistry, Jilin University; Changchun 130023 People's Republic of China
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education; Jilin University; Changchun 130023 People's Republic of China
| | - Hong-Xing Zhang
- Laboratory of Theoretical and Computational Chemistry; Institute of Theoretical Chemistry, Jilin University; Changchun 130023 People's Republic of China
- School of Pharmaceutical Sciences; Jilin University; Changchun 130022 People's Republic of China
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19
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Li Z, Kono H. Distinct Roles of Histone H3 and H2A Tails in Nucleosome Stability. Sci Rep 2016; 6:31437. [PMID: 27527579 PMCID: PMC4985630 DOI: 10.1038/srep31437] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 07/21/2016] [Indexed: 01/06/2023] Open
Abstract
Nucleosome breathing potentially increases the DNA exposure, which in turn recruits DNA-binding protein and regulates gene transcription. Numerous studies have shown the critical roles of N-terminal tails of histones H3 and H4 in gene expression; however, few studies have focused on the H2A C-terminal tail. Here we present thorough computational studies on a single nucleosome particle showing the linker DNA closing and opening, which is thought to be nucleosome breathing. With our simulation, the H2A C-terminal and H3 N-terminal tails were found to modulate the nucleosome conformation differently. The H2A C-terminal tail regulates nucleosome conformation by binding to linker DNA at different locations, whereas the H3 N-terminal tail regulates linker DNA by binding to it in different patterns. Further MD simulation on tail truncated structures corroborates this analysis. These findings replenish our understanding of the histone tail regulation mechanism on atomic level.
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Affiliation(s)
- Zhenhai Li
- Molecular Modeling and Simulation Group, National Institutes for Quantum and Radiological Science and Technology, 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
| | - Hidetoshi Kono
- Molecular Modeling and Simulation Group, National Institutes for Quantum and Radiological Science and Technology, 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
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21
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Ishida H, Matsumoto A. Mechanism for verification of mismatched and homoduplex DNAs by nucleotides-bound MutS analyzed by molecular dynamics simulations. Proteins 2016; 84:1287-303. [PMID: 27238299 DOI: 10.1002/prot.25077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/13/2016] [Accepted: 05/24/2016] [Indexed: 11/10/2022]
Abstract
In order to understand how MutS recognizes mismatched DNA and induces the reaction of DNA repair using ATP, the dynamics of the complexes of MutS (bound to the ADP and ATP nucleotides, or not) and DNA (with mismatched and matched base-pairs) were investigated using molecular dynamics simulations. As for DNA, the structure of the base-pairs of the homoduplex DNA which interacted with the DNA recognition site of MutS was intermittently disturbed, indicating that the homoduplex DNA was unstable. As for MutS, the disordered loops in the ATPase domains, which are considered to be necessary for the induction of DNA repair, were close to (away from) the nucleotide-binding sites in the ATPase domains when the nucleotides were (not) bound to MutS. This indicates that the ATPase domains changed their structural stability upon ATP binding using the disordered loop. Conformational analysis by principal component analysis showed that the nucleotide binding changed modes which have structurally solid ATPase domains and the large bending motion of the DNA from higher to lower frequencies. In the MutS-mismatched DNA complex bound to two nucleotides, the bending motion of the DNA at low frequency modes may play a role in triggering the formation of the sliding clamp for the following DNA-repair reaction step. Moreover, MM-PBSA/GBSA showed that the MutS-homoduplex DNA complex bound to two nucleotides was unstable because of the unfavorable interactions between MutS and DNA. This would trigger the ATP hydrolysis or separation of MutS and DNA to continue searching for mismatch base-pairs. Proteins 2016; 84:1287-1303. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Hisashi Ishida
- Quantum Beam Science Research Directorate, National Institutes for Quantum and Radiological Science and Technology, 8-1-7 Umemidai Kizugawa-Shi, Kyoto, 619-0215, Japan
| | - Atsushi Matsumoto
- Quantum Beam Science Research Directorate, National Institutes for Quantum and Radiological Science and Technology, 8-1-7 Umemidai Kizugawa-Shi, Kyoto, 619-0215, Japan
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22
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Korolev N, Yu H, Lyubartsev AP, Nordenskiöld L. Molecular dynamics simulations demonstrate the regulation of DNA-DNA attraction by H4 histone tail acetylations and mutations. Biopolymers 2016; 101:1051-64. [PMID: 24740714 DOI: 10.1002/bip.22499] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 04/09/2014] [Accepted: 04/11/2014] [Indexed: 01/08/2023]
Abstract
The positively charged N-terminal histone tails play a crucial role in chromatin compaction and are important modulators of DNA transcription, recombination, and repair. The detailed mechanism of the interaction of histone tails with DNA remains elusive. To model the unspecific interaction of histone tails with DNA, all-atom molecular dynamics (MD) simulations were carried out for systems of four DNA 22-mers in the presence of 20 or 16 short fragments of the H4 histone tail (variations of the 16-23 a. a. KRHRKVLR sequence, as well as the unmodified fragment a. a.13-20, GGAKRHRK). This setup with high DNA concentration, explicit presence of DNA-DNA contacts, presence of unstructured cationic peptides (histone tails) and K(+) mimics the conditions of eukaryotic chromatin. A detailed account of the DNA interactions with the histone tail fragments, K(+) and water is presented. Furthermore, DNA structure and dynamics and its interplay with the histone tail fragments binding are analysed. The charged side chains of the lysines and arginines play major roles in the tail-mediated DNA-DNA attraction by forming bridges and by coordinating to the phosphate groups and to the electronegative sites in the minor groove. Binding of all species to DNA is dynamic. The structure of the unmodified fully-charged H4 16-23 a.a. fragment KRHRKVLR is dominated by a stretched conformation. The H4 tail a. a. fragment GGAKRHRK as well as the H4 Lys16 acetylated fragment are highly flexible. The present work allows capturing typical features of the histone tail-counterion-DNA structure, interaction and dynamics.
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Affiliation(s)
- Nikolay Korolev
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
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23
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Nurse NP, Yuan C. Cis and trans internucleosomal interactions of H3 and H4 tails in tetranucleosomes. Biopolymers 2016; 103:33-40. [PMID: 25196374 DOI: 10.1002/bip.22560] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Accepted: 08/22/2014] [Indexed: 11/09/2022]
Abstract
Chromatin structure and the transcriptional state of a gene can be modulated by modifications made on H3 and H4 tails of histones. Elucidating the internucleosomal interactions of these tails is vital to understanding epigenetic regulation. Differentiation between cis (intra-nucleosomal) and trans (inter-nucleosomal) interactions is often difficult with conventional techniques since H3 and H4 tails are flexible. The distinction, however, is important because these interactions model short- and long-range chromatin interactions respectively and have different bearings in biological processes. Combining FCS and PCH analysis, we can decouple the contribution of histone tails to cis and trans effects. A Mg(2+) gradient was employed to facilitate compaction and oligomerization of tetranucleosomes with H3 and/or H4 tail truncations. H3 tails were found to play a multifunctional role and exhibit the ability to partake in both attractive cis and trans interactions simultaneously. H4 tails partake in attractive cis and repulsive trans interactions at low [Mg(2+)]. These interactions are diminished at higher [Mg(2+)]. Simultaneous H3 and H4 tail truncation inhibited array oligomerization but maintained local array compaction at relatively high [Mg(2+)]. The established experimental approach can be extended to study the detailed molecular interactions mediated by epigenetic modification of flexible histone tails.
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Affiliation(s)
- Nathan P Nurse
- School of Chemical Engineering, Purdue University, West Lafayette, IN, 47906
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24
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Erler J, Zhang R, Petridis L, Cheng X, Smith JC, Langowski J. The role of histone tails in the nucleosome: a computational study. Biophys J 2016; 107:2911-2922. [PMID: 25517156 DOI: 10.1016/j.bpj.2014.10.065] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 10/13/2014] [Accepted: 10/15/2014] [Indexed: 11/29/2022] Open
Abstract
Histone tails play an important role in gene transcription and expression. We present here a systematic computational study of the role of histone tails in the nucleosome, using replica exchange molecular dynamics simulations with an implicit solvent model and different well-established force fields. We performed simulations for all four histone tails, H4, H3, H2A, and H2B, isolated and with inclusion of the nucleosome. The results confirm predictions of previous theoretical studies for the secondary structure of the isolated tails but show a strong dependence on the force field used. In the presence of the entire nucleosome for all force fields, the secondary structure of the histone tails is destabilized. Specific contacts are found between charged lysine and arginine residues and DNA phosphate groups and other binding sites in the minor and major DNA grooves. Using cluster analysis, we found a single dominant configuration of binding to DNA for the H4 and H2A histone tails, whereas H3 and H2B show multiple binding configurations with an equal probability. The leading stabilizing contribution for those binding configurations is the attractive interaction between the positively charged lysine and arginine residues and the negatively charged phosphate groups, and thus the resulting charge neutralization. Finally, we present results of molecular dynamics simulations in explicit solvent to confirm our conclusions. Results from both implicit and explicit solvent models show that large portions of the histone tails are not bound to DNA, supporting the complex role of these tails in gene transcription and expression and making them possible candidates for binding sites of transcription factors, enzymes, and other proteins.
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Affiliation(s)
- Jochen Erler
- Division of Biophysics of Macromolecules, German Cancer Research Center, Heidelberg, Germany
| | - Ruihan Zhang
- Division of Biophysics of Macromolecules, German Cancer Research Center, Heidelberg, Germany
| | - Loukas Petridis
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Xiaolin Cheng
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Jeremy C Smith
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Jörg Langowski
- Division of Biophysics of Macromolecules, German Cancer Research Center, Heidelberg, Germany.
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25
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Saurabh S, Glaser MA, Lansac Y, Maiti PK. Atomistic Simulation of Stacked Nucleosome Core Particles: Tail Bridging, the H4 Tail, and Effect of Hydrophobic Forces. J Phys Chem B 2016; 120:3048-60. [DOI: 10.1021/acs.jpcb.5b11863] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Suman Saurabh
- Center
for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Matthew A. Glaser
- Department
of Physics and Liquid Crystal Materials Research Center, University of Colorado, Boulder, Colorado 80309, United States
| | - Yves Lansac
- GREMAN, Université François Rabelais, CNRS UMR 7347, 37200 Tours, France
- School
of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Prabal K. Maiti
- Center
for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, Karnataka 560012, India
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26
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Zhu P, Li G. Structural insights of nucleosome and the 30-nm chromatin fiber. Curr Opin Struct Biol 2016; 36:106-15. [PMID: 26872330 DOI: 10.1016/j.sbi.2016.01.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 01/14/2016] [Accepted: 01/22/2016] [Indexed: 01/15/2023]
Abstract
The eukaryotic genome is hierarchically packaged into chromatin in the nucleus. The organization and dynamics of 30-nm chromatin fibers, which is typically regarded as the secondary structure of chromatin, play a crucial role in regulating DNA accessibility for gene expression. Here we reviewed some recent progresses on the structural studies on nucleosomes, nucleosome-protein complexes, and chromatin fibers, focusing on the structural insights how the chromatin structure is regulated by different epigenetic regulation factors.
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Affiliation(s)
- Ping Zhu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Guohong Li
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
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27
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Recognition of the nucleosome by chromatin factors and enzymes. Curr Opin Struct Biol 2016; 37:54-61. [PMID: 26764865 DOI: 10.1016/j.sbi.2015.11.014] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 11/23/2015] [Accepted: 11/28/2015] [Indexed: 11/23/2022]
Abstract
Dynamic expression of the genome requires coordinated binding of chromatin factors and enzymes that carry out genome-templated processes. Until recently, the molecular mechanisms governing how these factors and enzymes recognize and act on the fundamental unit of chromatin, the nucleosome core particle, have remained a mystery. A small, yet growing set of structures of the nucleosome in complex with chromatin factors and enzymes highlights the importance of multivalency in defining nucleosome binding and specificity. Many such interactions include an arginine anchor motif, which targets a unique acidic patch on the nucleosome surface. These emerging paradigms for chromatin recognition will be discussed, focusing on several recent structural breakthroughs.
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28
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Collepardo-Guevara R, Portella G, Vendruscolo M, Frenkel D, Schlick T, Orozco M. Chromatin Unfolding by Epigenetic Modifications Explained by Dramatic Impairment of Internucleosome Interactions: A Multiscale Computational Study. J Am Chem Soc 2015; 137:10205-15. [PMID: 26192632 PMCID: PMC6251407 DOI: 10.1021/jacs.5b04086] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Histone tails and their epigenetic modifications play crucial roles in gene expression regulation by altering the architecture of chromatin. However, the structural mechanisms by which histone tails influence the interconversion between active and inactive chromatin remain unknown. Given the technical challenges in obtaining detailed experimental characterizations of the structure of chromatin, multiscale computations offer a promising alternative to model the effect of histone tails on chromatin folding. Here we combine multimicrosecond atomistic molecular dynamics simulations of dinucleosomes and histone tails in explicit solvent and ions, performed with three different state-of-the-art force fields and validated by experimental NMR measurements, with coarse-grained Monte Carlo simulations of 24-nucleosome arrays to describe the conformational landscape of histone tails, their roles in chromatin compaction, and the impact of lysine acetylation, a widespread epigenetic change, on both. We find that while the wild-type tails are highly flexible and disordered, the dramatic increase of secondary-structure order by lysine acetylation unfolds chromatin by decreasing tail availability for crucial fiber-compacting internucleosome interactions. This molecular level description of the effect of histone tails and their charge modifications on chromatin folding explains the sequence sensitivity and underscores the delicate connection between local and global structural and functional effects. Our approach also opens new avenues for multiscale processes of biomolecular complexes.
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Affiliation(s)
- Rosana Collepardo-Guevara
- Chemistry Department, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
- Joint BSC-CRG-IRB Pro-gramme on Computational Biology. Institute for Research in Biomedicine. Baldiri i Reixac 19. 08028, Barcelona, Spain
| | - Guillem Portella
- Chemistry Department, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
- Joint BSC-CRG-IRB Pro-gramme on Computational Biology. Institute for Research in Biomedicine. Baldiri i Reixac 19. 08028, Barcelona, Spain
| | - Michele Vendruscolo
- Chemistry Department, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Daan Frenkel
- Chemistry Department, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Tamar Schlick
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA
- Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, NY 10012, USA
| | - Modesto Orozco
- Joint BSC-CRG-IRB Pro-gramme on Computational Biology. Institute for Research in Biomedicine. Baldiri i Reixac 19. 08028, Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular. Facultat de Biologia. Universitat de Barcelona. Avgda Diagonal 643, 08028, Barcelona, Spain
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29
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Takahashi T, Vo Ngo BC, Xiao L, Arya G, Heller MJ. Molecular mechanical properties of short-sequence peptide enzyme mimics. J Biomol Struct Dyn 2015; 34:463-74. [DOI: 10.1080/07391102.2015.1039586] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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30
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Ozer G, Luque A, Schlick T. The chromatin fiber: multiscale problems and approaches. Curr Opin Struct Biol 2015; 31:124-39. [PMID: 26057099 DOI: 10.1016/j.sbi.2015.04.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 04/08/2015] [Accepted: 04/09/2015] [Indexed: 12/20/2022]
Abstract
The structure of chromatin, affected by many factors from DNA linker lengths to posttranslational modifications, is crucial to the regulation of eukaryotic cells. Combined experimental and computational methods have led to new insights into its structural and dynamical features, from interactions due to the flexible core histone tails or linker histones to the physical mechanism driving the formation of chromosomal domains. Here we present a perspective of recent advances in chromatin modeling techniques at the atomic, mesoscopic, and chromosomal scales with a view toward developing multiscale computational strategies to integrate such findings. Innovative modeling methods that connect molecular to chromosomal scales are crucial for interpreting experiments and eventually deciphering the complex dynamic organization and function of chromatin in the cell.
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Affiliation(s)
- Gungor Ozer
- Department of Chemistry, 100 Washington Square East, New York University, New York, NY 10003, USA
| | - Antoni Luque
- Department of Chemistry, 100 Washington Square East, New York University, New York, NY 10003, USA; Current address: Department of Mathematics & Statistics and Viral Information Institute, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-7720, USA
| | - Tamar Schlick
- Department of Chemistry, 100 Washington Square East, New York University, New York, NY 10003, USA; Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, NY 10012, USA; NYU-ECNU Center for Computational Chemistry at NYU Shanghai, 3663 Zhongshan Road North, Shanghai 200062, China.
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31
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Winogradoff D, Echeverria I, Potoyan DA, Papoian GA. The Acetylation Landscape of the H4 Histone Tail: Disentangling the Interplay between the Specific and Cumulative Effects. J Am Chem Soc 2015; 137:6245-53. [DOI: 10.1021/jacs.5b00235] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- David Winogradoff
- Chemical
Physics Program and ‡Department of Chemistry and Biochemistry and
Institute for Physical Science and Technology, University of Maryland, College
Park, Maryland 20742, United States
| | - Ignacia Echeverria
- Chemical
Physics Program and ‡Department of Chemistry and Biochemistry and
Institute for Physical Science and Technology, University of Maryland, College
Park, Maryland 20742, United States
| | - Davit A. Potoyan
- Chemical
Physics Program and ‡Department of Chemistry and Biochemistry and
Institute for Physical Science and Technology, University of Maryland, College
Park, Maryland 20742, United States
| | - Garegin A. Papoian
- Chemical
Physics Program and ‡Department of Chemistry and Biochemistry and
Institute for Physical Science and Technology, University of Maryland, College
Park, Maryland 20742, United States
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32
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Wilkins BJ, Hahn LE, Heitmüller S, Frauendorf H, Valerius O, Braus GH, Neumann H. Genetically encoding lysine modifications on histone H4. ACS Chem Biol 2015; 10:939-44. [PMID: 25590375 DOI: 10.1021/cb501011v] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Post-translational modifications of proteins are important modulators of protein function. In order to identify the specific consequences of individual modifications, general methods are required for homogeneous production of modified proteins. The direct installation of modified amino acids by genetic code expansion facilitates the production of such proteins independent of the knowledge and availability of the enzymes naturally responsible for the modification. The production of recombinant histone H4 with genetically encoded modifications has proven notoriously difficult in the past. Here, we present a general strategy to produce histone H4 with acetylation, propionylation, butyrylation, and crotonylation on lysine residues. We produce homogeneous histone H4 containing up to four simultaneous acetylations to analyze the impact of the modifications on chromatin array compaction. Furthermore, we explore the ability of antibodies to discriminate between alternative lysine acylations by incorporating these modifications in recombinant histone H4.
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Affiliation(s)
- Bryan J. Wilkins
- Free
Floater (Junior) Research Group “Applied Synthetic Biology”,
Institute for Microbiology and Genetics, Georg-August University Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
| | - Liljan E. Hahn
- Free
Floater (Junior) Research Group “Applied Synthetic Biology”,
Institute for Microbiology and Genetics, Georg-August University Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
| | - Svenja Heitmüller
- Free
Floater (Junior) Research Group “Applied Synthetic Biology”,
Institute for Microbiology and Genetics, Georg-August University Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
| | - Holm Frauendorf
- Institute
for Organic and Biomolecular Chemistry, Georg-August University Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany
| | - Oliver Valerius
- Institute
for Microbiology and Genetics, Georg-August University Göttingen, Grisebachstrasse 8, 37077 Göttingen, Germany
| | - Gerhard H. Braus
- Institute
for Microbiology and Genetics, Georg-August University Göttingen, Grisebachstrasse 8, 37077 Göttingen, Germany
| | - Heinz Neumann
- Free
Floater (Junior) Research Group “Applied Synthetic Biology”,
Institute for Microbiology and Genetics, Georg-August University Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
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33
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Zheng Y, Cui Q. The histone H3 N-terminal tail: a computational analysis of the free energy landscape and kinetics. Phys Chem Chem Phys 2015; 17:13689-98. [DOI: 10.1039/c5cp01858g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Extensive molecular dynamics simulations and Markov State models are used to characterize the free energy landscape and kinetics of the histone H3 N-terminal tail, which plays a critical role in regulating chromatin dynamics and gene activity.
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Affiliation(s)
- Yuqing Zheng
- Graduate Program in Biophysics
- University of Wisconsin-Madison
- Madison
- USA
| | - Qiang Cui
- Graduate Program in Biophysics
- University of Wisconsin-Madison
- Madison
- USA
- Department of Chemistry and Theoretical Chemistry Institute
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34
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Affiliation(s)
- Robert K McGinty
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Song Tan
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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35
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Kabra H, Hwang Y, Lim HL, Kar M, Arya G, Varghese S. Biomimetic Material-Assisted Delivery of Human Embryonic Stem Cell Derivatives for Enhanced In Vivo Survival and Engraftment. ACS Biomater Sci Eng 2014; 1:7-12. [PMID: 26280019 DOI: 10.1021/ab500021a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The ability of human embryonic stem cells (hESCs) and their derivatives to differentiate and contribute to tissue repair has enormous potential to treat various debilitating diseases. However, improving the in vivo viability and function of the transplanted cells, a key determinant of translating cell-based therapies to the clinic, remains a daunting task. Here, we develop a hybrid biomaterial consisting of hyaluronic acid (HA) grafted with 6-aminocaproic acid moieties (HA-6ACA) to improve cell delivery and their subsequent in vivo function using skeletal muscle as a model system. Our findings show that the biomimetic material-assisted delivery of hESC-derived myogenic progenitor cells into cardiotoxin-injured skeletal muscles of NOD/SCID mice significantly promotes survival and engraftment of transplanted cells in a dose-dependent manner. The donor cells were found to contribute to the regeneration of damaged muscle fibers and to the satellite cell (muscle specific stem cells) compartment. Such biomimetic cell delivery vehicles that are cost-effective and easy-to-synthesize could play a key role in improving the outcomes of other stem cell-based therapies.
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Affiliation(s)
- Harsha Kabra
- Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Yongsung Hwang
- Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Han Liang Lim
- Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Mrityunjoy Kar
- Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Gaurav Arya
- Department of NanoEngineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Shyni Varghese
- Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, United States
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36
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Migliori AD, Smith DE, Arya G. Molecular interactions and residues involved in force generation in the T4 viral DNA packaging motor. J Mol Biol 2014; 426:4002-4017. [PMID: 25311860 DOI: 10.1016/j.jmb.2014.09.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 09/21/2014] [Accepted: 09/26/2014] [Indexed: 10/24/2022]
Abstract
Many viruses utilize molecular motors to package their genomes into preformed capsids. A striking feature of these motors is their ability to generate large forces to drive DNA translocation against entropic, electrostatic, and bending forces resisting DNA confinement. A model based on recently resolved structures of the bacteriophage T4 motor protein gp17 suggests that this motor generates large forces by undergoing a conformational change from an extended to a compact state. This transition is proposed to be driven by electrostatic interactions between complementarily charged residues across the interface between the N- and C-terminal domains of gp17. Here we use atomistic molecular dynamics simulations to investigate in detail the molecular interactions and residues involved in such a compaction transition of gp17. We find that although electrostatic interactions between charged residues contribute significantly to the overall free energy change of compaction, interactions mediated by the uncharged residues are equally if not more important. We identify five charged residues and six uncharged residues at the interface that play a dominant role in the compaction transition and also reveal salt bridging, van der Waals, and solvent hydrogen-bonding interactions mediated by these residues in stabilizing the compact form of gp17. The formation of a salt bridge between Glu309 and Arg494 is found to be particularly crucial, consistent with experiments showing complete abrogation in packaging upon Glu309Lys mutation. The computed contributions of several other residues are also found to correlate well with single-molecule measurements of impairments in DNA translocation activity caused by site-directed mutations.
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Affiliation(s)
- Amy D Migliori
- Department of Physics, University of California at San Diego, La Jolla, CA 92093, USA
| | - Douglas E Smith
- Department of Physics, University of California at San Diego, La Jolla, CA 92093, USA.
| | - Gaurav Arya
- Department of NanoEngineering, University of California at San Diego, La Jolla, CA 92093, USA.
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37
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Pepenella S, Murphy KJ, Hayes JJ. A distinct switch in interactions of the histone H4 tail domain upon salt-dependent folding of nucleosome arrays. J Biol Chem 2014; 289:27342-27351. [PMID: 25122771 DOI: 10.1074/jbc.m114.595140] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The core histone tail domains mediate inter-nucleosomal interactions that direct folding and condensation of nucleosome arrays into higher-order chromatin structures. The histone H4 tail domain facilitates inter-array interactions by contacting both the H2A/H2B acidic patch and DNA of neighboring nucleosomes. Likewise, H4 tail-H2A contacts stabilize array folding. However, whether the H4 tail domains stabilize array folding via inter-nucleosomal interactions with the DNA of neighboring nucleosomes remains unclear. We utilized defined oligonucleosome arrays containing a single specialized nucleosome with a photo-inducible cross-linker in the N terminus of the H4 tail to characterize these interactions. We observed that the H4 tail participates exclusively in intra-array interactions with DNA in unfolded arrays. These interactions are diminished during array folding, yet no inter-nucleosome, intra-array H4 tail-DNA contacts are observed in condensed chromatin. However, we document contacts between the N terminus of the H4 tail and H2A. Installation of acetylation mimics known to disrupt H4-H2A surface interactions did not increase observance of H4-DNA inter-nucleosomal interactions. These results suggest the multiple functions of the H4 tail require targeted distinct interactions within condensed chromatin.
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Affiliation(s)
- Sharon Pepenella
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, New York 14642
| | - Kevin J Murphy
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, New York 14642
| | - Jeffrey J Hayes
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, New York 14642.
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38
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Razin SV, Gavrilov AA. Chromatin without the 30-nm fiber: constrained disorder instead of hierarchical folding. Epigenetics 2014; 9:653-7. [PMID: 24561903 PMCID: PMC4063823 DOI: 10.4161/epi.28297] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Several hierarchical levels of DNA packaging are believed to exist in chromatin, starting from a 10-nm chromatin fiber that is further packed into a 30-nm fiber. Transitions between the 30-nm and 10-nm fibers are thought to be essential for the control of chromatin transcriptional status. However, recent studies demonstrate that in the nuclei, DNA is packed in tightly associated 10-nm fibers that are not compacted into 30-nm fibers. Additionally, the accessibility of DNA in chromatin depends on the local mobility of nucleosomes rather than on decompaction of chromosome regions. These findings argue for reconsidering the hierarchical model of chromatin packaging and some of the basic definitions of chromatin. In particular, chromatin domains should be considered as three-dimensional objects, which may include genomic regions that do not necessarily constitute a continuous domain on the DNA chain.
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Affiliation(s)
- Sergey V Razin
- Institute of Gene Biology of the Russian Academy of Sciences; Moscow, Russia; Faculty of Biology; M.V. Lomonosov Moscow State University; Moscow, Russia; LIA 1066 French-Russian Joint Cancer Research Laboratory; Moscow, Russia
| | - Alexey A Gavrilov
- Institute of Gene Biology of the Russian Academy of Sciences; Moscow, Russia; LIA 1066 French-Russian Joint Cancer Research Laboratory; Moscow, Russia
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39
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Vellore NA, Baron R. Epigenetic molecular recognition: a biomolecular modeling perspective. ChemMedChem 2014; 9:484-94. [PMID: 24616246 DOI: 10.1002/cmdc.201300510] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Indexed: 01/23/2023]
Abstract
The abnormal regulation of epigenetic protein families is associated with the onset and progression of various human diseases. However, epigenetic processes remain relatively obscure at the molecular level, thus preventing the rational design of chemical therapeutics. An array of robust computational and modeling approaches can complement experiments to shed light on the complex mechanisms of epigenetic molecular recognition and can guide medicinal chemists in designing selective and potent drug molecules. Herein we present a review of studies focused on epigenetic molecular recognition from a biomolecular modeling viewpoint. Although the known epigenetic targets are numerous, this review focuses on the more limited protein families on which computational modeling has been successfully applied. Therefore, we review three main topics: 1) histone deacetylases, 2) histone demethylases, and 3) histone tail dynamics. A brief review of the biological background and biomedical relevance is presented for each topic, followed by a detailed discussion of the computational studies and their relevance.
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Affiliation(s)
- Nadeem A Vellore
- Department of Medicinal Chemistry, College of Pharmacy and The Henry Eyring Center for Theoretical Chemistry, The University of Utah, 30 South 2000 East, Salt Lake City, UT 84112 (USA)
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40
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Turner BM. Nucleosome signalling; an evolving concept. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:623-6. [PMID: 24412235 DOI: 10.1016/j.bbagrm.2014.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 01/02/2014] [Indexed: 11/16/2022]
Abstract
The nucleosome core particle is the first stage of DNA packaging in virtually all eukaryotes. It both organises nuclear DNA and protects it from adventitious binding of transcription factors and the consequent deregulation of gene expression. Both properties are essential to allow the genome expansion characteristic of complex eukaryotes. The nucleosome is a flexible structure in vivo, allowing selective relaxation of its intrinsically inhibitory effects in response to external signals. Structural changes are brought about by dedicated remodelling enzymes and by posttranslational modifications of the core histones. Histone modifications occasionally alter nucleosome structure directly, but their more usual roles are to act as receptors on the nucleosome surface that are recognised by specific protein domains. The bound proteins, in turn, affect nucleosome structure and function. This strategy enormously expands the signalling capacity of the nucleosome and its ability to influence both the initiation and elongation stages of transcription. The enzymes responsible for placing and removing histone modifications, and the modification-binding proteins themselves, are ubiquitous, numerous and conserved amongst eukaryotes. Like the nucleosome, they date back to the earliest eukaryotes and may have played integral and essential roles in eukaryotic evolution. The present properties and epigenetic functions of the nucleosome reflect its evolutionary past and the selective pressures to which it has responded and can be better understood in this context. This article is part of a Special Issue entitled: Molecular mechanisms of histone modification function.
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Affiliation(s)
- Bryan M Turner
- School of Cancer Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
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41
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Erdel F, Müller-Ott K, Rippe K. Establishing epigenetic domains via chromatin-bound histone modifiers. Ann N Y Acad Sci 2013; 1305:29-43. [PMID: 24033539 DOI: 10.1111/nyas.12262] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The eukaryotic nucleus harbors the DNA genome, which associates with histones and other chromosomal proteins into a complex referred to as chromatin. It provides an additional layer of so-called epigenetic information via histone modifications and DNA methylation on top of the DNA sequence that determines the cell's active gene expression program. The nucleus is devoid of internal organelles separated by membranes. Thus, free diffusive transport of proteins and RNA can occur throughout the space accessible for a given macromolecule. At the same time, chromatin is partitioned into different specialized structures such as nucleoli, chromosome territories, and heterochromatin domains that serve distinct functions. Here, we address the question of how the activity of chromatin-modifying enzymes is confined to chromatin subcompartments. We discuss mechanisms for establishing activity gradients of diffusive chromatin-modifying enzymes that could give rise to distinct chromatin domains within the cell nucleus. Interestingly, such gradients might directly result from immobilization of the enzymes on the flexible chromatin chain. Thus, locus-specific tethering of these enzymes to chromatin could have the potential to establish, maintain, or modulate epigenetic patterns of characteristic domain size.
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Affiliation(s)
- Fabian Erdel
- Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, Research Group Genome Organization & Function, Im Neuenheimer Feld 280, Heidelberg, Germany
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Nurse NP, Jimenez-Useche I, Smith IT, Yuan C. Clipping of flexible tails of histones H3 and H4 affects the structure and dynamics of the nucleosome. Biophys J 2013; 104:1081-8. [PMID: 23473491 DOI: 10.1016/j.bpj.2013.01.019] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 12/31/2012] [Accepted: 01/14/2013] [Indexed: 01/21/2023] Open
Abstract
Förster resonance energy transfer was used to monitor the dynamic conformations of mononucleosomes under different chromatin folding conditions to elucidate the role of the flexible N-terminal regions of H3 and H4 histones. The H3 tail was shown to partake in intranucleosomal interactions by restricting the DNA breathing motion and compacting the nucleosome. The H3 tail effects were mostly independent of the ionic strength and valency of the ions. The H4 tail was shown to not greatly affect the nucleosome conformation, but did slightly influence the relative population of the preferred conformation. The role of the H4 tail varied depending on the valency and ionic strength, suggesting that electrostatic forces play a primary role in H4 tail interactions. Interestingly, despite the H4 tail's lack of influence, when H3 and H4 tails were simultaneously clipped, a more dramatic effect was seen than when only H3 or H4 tails were clipped. The combinatorial effect of H3 and H4 tail truncation suggests a potential mechanism by which various combinations of histone tail modifications can be used to control accessibility of DNA-binding proteins to nucleosomal DNA.
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Affiliation(s)
- Nathan P Nurse
- School of Chemical Engineering, Purdue University, West Lafayette, Indiana, USA
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Kalashnikova AA, Porter-Goff ME, Muthurajan UM, Luger K, Hansen JC. The role of the nucleosome acidic patch in modulating higher order chromatin structure. J R Soc Interface 2013; 10:20121022. [PMID: 23446052 DOI: 10.1098/rsif.2012.1022] [Citation(s) in RCA: 173] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Higher order folding of chromatin fibre is mediated by interactions of the histone H4 N-terminal tail domains with neighbouring nucleosomes. Mechanistically, the H4 tails of one nucleosome bind to the acidic patch region on the surface of adjacent nucleosomes, causing fibre compaction. The functionality of the chromatin fibre can be modified by proteins that interact with the nucleosome. The co-structures of five different proteins with the nucleosome (LANA, IL-33, RCC1, Sir3 and HMGN2) recently have been examined by experimental and computational studies. Interestingly, each of these proteins displays steric, ionic and hydrogen bond complementarity with the acidic patch, and therefore will compete with each other for binding to the nucleosome. We first review the molecular details of each interface, focusing on the key non-covalent interactions that stabilize the protein-acidic patch interactions. We then propose a model in which binding of proteins to the nucleosome disrupts interaction of the H4 tail domains with the acidic patch, preventing the intrinsic chromatin folding pathway and leading to assembly of alternative higher order chromatin structures with unique biological functions.
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Affiliation(s)
- Anna A Kalashnikova
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
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Fan Y, Korolev N, Lyubartsev AP, Nordenskiöld L. An advanced coarse-grained nucleosome core particle model for computer simulations of nucleosome-nucleosome interactions under varying ionic conditions. PLoS One 2013; 8:e54228. [PMID: 23418426 PMCID: PMC3572162 DOI: 10.1371/journal.pone.0054228] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 12/11/2012] [Indexed: 11/19/2022] Open
Abstract
In the eukaryotic cell nucleus, DNA exists as chromatin, a compact but dynamic complex with histone proteins. The first level of DNA organization is the linear array of nucleosome core particles (NCPs). The NCP is a well-defined complex of 147 bp DNA with an octamer of histones. Interactions between NCPs are of paramount importance for higher levels of chromatin compaction. The polyelectrolyte nature of the NCP implies that nucleosome-nucleosome interactions must exhibit a great influence from both the ionic environment as well as the positively charged and highly flexible N-terminal histone tails, protruding out from the NCP. The large size of the system precludes a modelling analysis of chromatin at an all-atom level and calls for coarse-grained approximations. Here, a model of the NCP that include the globular histone core and the flexible histone tails described by one particle per each amino acid and taking into account their net charge is proposed. DNA wrapped around the histone core was approximated at the level of two base pairs represented by one bead (bases and sugar) plus four beads of charged phosphate groups. Computer simulations, using a Langevin thermostat, in a dielectric continuum with explicit monovalent (K(+)), divalent (Mg(2+)) or trivalent (Co(NH(3))(6) (3+)) cations were performed for systems with one or ten NCPs. Increase of the counterion charge results in a switch from repulsive NCP-NCP interaction in the presence of K(+), to partial aggregation with Mg(2+) and to strong mutual attraction of all 10 NCPs in the presence of CoHex(3+). The new model reproduced experimental results and the structure of the NCP-NCP contacts is in agreement with available data. Cation screening, ion-ion correlations and tail bridging contribute to the NCP-NCP attraction and the new NCP model accounts for these interactions.
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Affiliation(s)
- Yanping Fan
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Nikolay Korolev
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail: (NK); (APL)
| | - Alexander P. Lyubartsev
- Division of Physical Chemistry, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm, Sweden
- * E-mail: (NK); (APL)
| | - Lars Nordenskiöld
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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du Preez LL, Patterton HG. Secondary structures of the core histone N-terminal tails: their role in regulating chromatin structure. Subcell Biochem 2013; 61:37-55. [PMID: 23150245 DOI: 10.1007/978-94-007-4525-4_2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The core histone N-terminal tails dissociate from their binding positions in nucleosomes at moderate salt concentrations, and appear unstructured in the crystal. This suggested that the tails contributed minimally to chromatin structure. However, in vitro studies have shown that the tails were involved in a range of intra- and inter-nucleosomal as well as inter-fibre contacts. The H4 tail, which is essential for chromatin compaction, was shown to contact an adjacent nucleosome in the crystal. Acetylation of H4K16 was shown to abolish the ability of a nucleosome array to fold into a 30 nm fibre. The application of secondary structure prediction software has suggested the presence of extended structured regions in the histone tails. Molecular Dynamics studies have further shown that sections of the H3 and H4 tails assumed α-helical and β-strand content that was enhanced by the presence of DNA, and that post-translational modifications of the tails had a major impact on these structures. Circular dichroism and NMR showed that the H3 and H4 tails exhibited significant α-helical content, that was increased by acetylation of the tail. There is thus strong evidence, both from biophysical and from computational approaches, that the core histones tails, particularly that of H3 and H4, are structured, and that these structures are influenced by post-translational modifications. This chapter reviews studies on the position, binding sites and secondary structures of the core histone tails, and discusses the possible role of the histone tail structures in the regulation of chromatin organization, and its impact on human disease.
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Affiliation(s)
- Louis L du Preez
- Advanced Biomolecular Research Cluster, University of the Free State, 339, Bloemfontein, 9300, South Africa
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Choy JS, Lee TH. Structural dynamics of nucleosomes at single-molecule resolution. Trends Biochem Sci 2012; 37:425-35. [PMID: 22831768 DOI: 10.1016/j.tibs.2012.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 06/22/2012] [Accepted: 06/29/2012] [Indexed: 11/29/2022]
Abstract
The detailed mechanisms of how DNA that is assembled around a histone core can be accessed by DNA-binding proteins for transcription, replication, or repair, remain elusive nearly 40 years after Kornberg's nucleosome model was proposed. Uncovering the structural dynamics of nucleosomes is a crucial step in elucidating the mechanisms regulating genome accessibility. This requires the deconvolution of multiple structural states within an ensemble. Recent advances in single-molecule methods enable unprecedented efficiency in examining subpopulation dynamics. In this review, we summarize studies of nucleosome structure and dynamics from single-molecule approaches and how they advance our understanding of the mechanisms that govern DNA transactions.
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Affiliation(s)
- John S Choy
- Department of Physics, Bio-X Program, Stanford University, Stanford, CA 94305, USA.
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47
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Korolev N, Fan Y, Lyubartsev AP, Nordenskiöld L. Modelling chromatin structure and dynamics: status and prospects. Curr Opin Struct Biol 2012; 22:151-9. [PMID: 22305428 DOI: 10.1016/j.sbi.2012.01.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 01/12/2012] [Accepted: 01/13/2012] [Indexed: 11/28/2022]
Abstract
The packaging of genomic DNA into chromatin in the eukaryotic cell nucleus demands extensive compaction. This requires attractive nucleosome-nucleosome interactions to overcome repulsion between the negatively charged DNA segments as well as other constraints. At the same time, DNA must be dynamically accessible to the cellular machinery that operates on it. Recent progress in the experimental characterisation of the higher order structure and dynamics of well-defined chromatin fibres has stimulated the attempts at theoretical description of chromatin and the nucleosome. Here we review the present status of chromatin modelling, with particular emphasis on coarse-grained computer simulation models, the role of electrostatic interactions, and discuss future perspectives in the field.
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Affiliation(s)
- Nikolay Korolev
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, 637551, Singapore
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48
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Schlick T, Hayes J, Grigoryev S. Toward convergence of experimental studies and theoretical modeling of the chromatin fiber. J Biol Chem 2011; 287:5183-91. [PMID: 22157002 DOI: 10.1074/jbc.r111.305763] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Understanding the structural organization of eukaryotic chromatin and its control of gene expression represents one of the most fundamental and open challenges in modern biology. Recent experimental advances have revealed important characteristics of chromatin in response to changes in external conditions and histone composition, such as the conformational complexity of linker DNA and histone tail domains upon compact folding of the fiber. In addition, modeling studies based on high-resolution nucleosome models have helped explain the conformational features of chromatin structural elements and their interactions in terms of chromatin fiber models. This minireview discusses recent progress and evidence supporting structural heterogeneity in chromatin fibers, reconciling apparently contradictory fiber models.
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Affiliation(s)
- Tamar Schlick
- Department of Chemistry, New York University, New York, New York 10003, USA.
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49
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Finding a balance: how diverse dosage compensation strategies modify histone h4 to regulate transcription. GENETICS RESEARCH INTERNATIONAL 2011; 2012:795069. [PMID: 22567401 PMCID: PMC3335593 DOI: 10.1155/2012/795069] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 08/08/2011] [Indexed: 01/21/2023]
Abstract
Dosage compensation balances gene expression levels between the sex chromosomes and autosomes and sex-chromosome-linked gene expression levels between the sexes. Different dosage compensation strategies evolved in different lineages, but all involve changes in chromatin. This paper discusses our current understanding of how modifications of the histone H4 tail, particularly changes in levels of H4 lysine 16 acetylation and H4 lysine 20 methylation, can be used in different contexts to either modulate gene expression levels twofold or to completely inhibit transcription.
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50
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Abstract
Chromatin is by its very nature a repressive environment which restricts the recruitment of transcription factors and acts as a barrier to polymerases. Therefore the complex process of gene activation must operate at two levels. In the first instance, localized chromatin decondensation and nucleosome displacement is required to make DNA accessible. Second, sequence-specific transcription factors need to recruit chromatin modifiers and remodellers to create a chromatin environment that permits the passage of polymerases. In this review I will discuss the chromatin structural changes that occur at active gene loci and at regulatory elements that exist as DNase I hypersensitive sites.
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Affiliation(s)
- Peter N Cockerill
- Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, UK.
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