1
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Liu R, Zhang L, Zhang K. Histone modification in psoriasis: Molecular mechanisms and potential therapeutic targets. Exp Dermatol 2024; 33:e15151. [PMID: 39090854 DOI: 10.1111/exd.15151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 06/24/2024] [Accepted: 07/19/2024] [Indexed: 08/04/2024]
Abstract
Psoriasis is an immune-mediated, inflammatory disease. Genetic and environmental elements are involved in the nosogenesis of this illness. Epigenetic inheritance serves as the connection between genetic and environmental factors. Histone modification, an epigenetic regulatory mechanism, is implicated in the development of numerous diseases. The basic function of histone modification is to regulate cellular functions by modifying gene expression. Modulation of histone modification, such as regulation of enzymes pertinent to histone modification, can be an alternative approach for treating some diseases, including psoriasis. Herein, we reviewed the regulatory mechanisms and biological effects of histone modifications and their roles in the pathogenesis of psoriasis.
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Affiliation(s)
- Ruifeng Liu
- Shanxi Key Laboratory of Stem Cells for Immunological Dermatosis, Institute of Dermatology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, China
| | - Luyao Zhang
- Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Kaiming Zhang
- Shanxi Key Laboratory of Stem Cells for Immunological Dermatosis, Institute of Dermatology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, China
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2
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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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3
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Orsetti A, van Oosten D, Vasarhelyi RG, Dănescu TM, Huertas J, van Ingen H, Cojocaru V. Structural dynamics in chromatin unraveling by pioneer transcription factors. Biophys Rev 2024; 16:365-382. [PMID: 39099839 PMCID: PMC11297019 DOI: 10.1007/s12551-024-01205-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 06/18/2024] [Indexed: 08/06/2024] Open
Abstract
Pioneer transcription factors are proteins with a dual function. First, they regulate transcription by binding to nucleosome-free DNA regulatory elements. Second, they bind to DNA while wrapped around histone proteins in the chromatin and mediate chromatin opening. The molecular mechanisms that connect the two functions are yet to be discovered. In recent years, pioneer factors received increased attention mainly because of their crucial role in promoting cell fate transitions that could be used for regenerative therapies. For example, the three factors required to induce pluripotency in somatic cells, Oct4, Sox2, and Klf4 were classified as pioneer factors and studied extensively. With this increased attention, several structures of complexes between pioneer factors and chromatin structural units (nucleosomes) have been resolved experimentally. Furthermore, experimental and computational approaches have been designed to study two unresolved, key scientific questions: First, do pioneer factors induce directly local opening of nucleosomes and chromatin fibers upon binding? And second, how do the unstructured tails of the histones impact the structural dynamics involved in such conformational transitions? Here we review the current knowledge about transcription factor-induced nucleosome dynamics and the role of the histone tails in this process. We discuss what is needed to bridge the gap between the static views obtained from the experimental structures and the key structural dynamic events in chromatin opening. Finally, we propose that integrating nuclear magnetic resonance spectroscopy with molecular dynamics simulations is a powerful approach to studying pioneer factor-mediated dynamics of nucleosomes and perhaps small chromatin fibers using native DNA sequences.
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Affiliation(s)
- Andrea Orsetti
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Daphne van Oosten
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | | | - Theodor-Marian Dănescu
- Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Jan Huertas
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, England
| | - Hugo van Ingen
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Vlad Cojocaru
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
- STAR-UBB Institute, Babeş-Bolyai University, Cluj-Napoca, Romania
- Max Planck Institute for Molecular Biomedicine, Münster, Germany
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4
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Portillo-Ledesma S, Schlick T. Regulation of chromatin architecture by protein binding: insights from molecular modeling. Biophys Rev 2024; 16:331-343. [PMID: 39099845 PMCID: PMC11297222 DOI: 10.1007/s12551-024-01195-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 04/22/2024] [Indexed: 08/06/2024] Open
Abstract
Histone and non-histone proteins play key roles in the activation and repression of genes. In addition to experimental studies of their regulation of gene expression, molecular modeling at the nucleosome, chromatin, and chromosome levels can contribute insights into the molecular mechanisms involved. In this review, we provide an overview for protein-bound chromatin modeling, and describe how our group has integrated protein binding into genome systems across the scales, from all-atom to coarse-grained models, using explicit to implicit descriptions. We describe the associated applications to protein binding effects and biological mechanisms of genome folding and gene regulation. We end by illustrating the application of machine learning tools like AlphaFold2 to proteins relevant to chromatin systems.
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Affiliation(s)
- Stephanie Portillo-Ledesma
- Department of Chemistry, 100 Washington Square East, Silver Building, New York University, New York, NY 10003 USA
- Simons Center for Computational Physical Chemistry, 24 Waverly Place, Silver Building, New York University, New York, NY 10003 USA
| | - Tamar Schlick
- Department of Chemistry, 100 Washington Square East, Silver Building, New York University, New York, NY 10003 USA
- Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, NY 10012 USA
- New York University-East China Normal University Center for Computational Chemistry, New York University Shanghai, Shanghai, 200122 China
- Simons Center for Computational Physical Chemistry, 24 Waverly Place, Silver Building, New York University, New York, NY 10003 USA
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5
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Yang L, Ruan Y, Xu H. HIST3H2A promotes the progression of prostate cancer through inhibiting cell necroptosis. BMC Cancer 2024; 24:544. [PMID: 38684944 PMCID: PMC11059659 DOI: 10.1186/s12885-024-12308-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 04/24/2024] [Indexed: 05/02/2024] Open
Abstract
In recent years, there has been an increase in the incidence and mortality rates of prostate cancer (PCa). However, the specific molecular mechanisms underlying its occurrence and development remain unclear, necessitating the identification of new therapeutic targets. Through bioinformatics analysis, we discovered a previously unstudied differential gene called HIST3H2A in prostate cancer. Our study revealed that HIST3H2A is highly expressed in PCa tissues, as confirmed by analysis of both the GEO and UALCAN databases. Further analysis using the KEGG database demonstrated that HIST3H2A regulates the pathway of programmed necroptosis in cells. Additionally, we observed significant up-regulation of HIST3H2A in PCa tissues and cell lines. HIST3H2A was found to regulate cell proliferation, migration, invasion, and the epithelial-mesenchymal transition (EMT) process in tumors. Notably, HIST3H2A's role in regulating programmed necroptosis in prostate cancer cells differs from its role in apoptosis. In vitro and in vivo experiments collectively support the key role of HIST3H2A in promoting the development of prostate cancer, highlighting its potential as a therapeutic target for patients with PCa.
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Affiliation(s)
- Lihong Yang
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, College of Life Sciences, Guizhou University, Guiyang, 550025, China
| | - Yong Ruan
- College of Animal Science, Guizhou University, Guiyang, 550025, China
| | - Houqiang Xu
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, College of Life Sciences, Guizhou University, Guiyang, 550025, China.
- College of Animal Science, Guizhou University, Guiyang, 550025, China.
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6
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Khatua P, Tang PK, Moulick AG, Patel R, Manandhar A, Loverde SM. Sequence Dependence in Nucleosome Dynamics. J Phys Chem B 2024; 128:3090-3101. [PMID: 38530903 PMCID: PMC11181342 DOI: 10.1021/acs.jpcb.3c07363] [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] [Indexed: 03/28/2024]
Abstract
The basic packaging unit of eukaryotic chromatin is the nucleosome that contains 145-147 base pair duplex DNA wrapped around an octameric histone protein. While the DNA sequence plays a crucial role in controlling the positioning of the nucleosome, the molecular details behind the interplay between DNA sequence and nucleosome dynamics remain relatively unexplored. This study analyzes this interplay in detail by performing all-atom molecular dynamics simulations of nucleosomes, comparing the human α-satellite palindromic (ASP) and the strong positioning "Widom-601" DNA sequence at time scales of 12 μs. The simulations are performed at salt concentrations 10-20 times higher than physiological salt concentrations to screen the electrostatic interactions and promote unwrapping. These microsecond-long simulations give insight into the molecular-level sequence-dependent events that dictate the pathway of DNA unwrapping. We find that the "ASP" sequence forms a loop around SHL ± 5 for three sets of simulations. Coincident with loop formation is a cooperative increase in contacts with the neighboring N-terminal H2B tail and C-terminal H2A tail and the release of neighboring counterions. We find that the Widom-601 sequence exhibits a strong breathing motion of the nucleic acid ends. Coincident with the breathing motion is the collapse of the full N-terminal H3 tail and formation of an α-helix that interacts with the H3 histone core. We postulate that the dynamics of these histone tails and their modification with post-translational modifications (PTMs) may play a key role in governing this dynamics.
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Affiliation(s)
- Prabir Khatua
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New York, 10314, United States
- Present Address: Department of Chemistry, GITAM School of Science, GITAM (Deemed to be University), Bengaluru, 562163, INDIA
| | - Phu K. Tang
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New York, 10314, United States
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, United States
- Present Address: Flatiron Institute, New York, NY, 10010, United States
- These authors contributed equally: Phu K. Tang, Abhik Ghosh Moulick, and Rutika Patel
| | - Abhik Ghosh Moulick
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New York, 10314, United States
- These authors contributed equally: Phu K. Tang, Abhik Ghosh Moulick, and Rutika Patel
| | - Rutika Patel
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New York, 10314, United States
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, United States
- These authors contributed equally: Phu K. Tang, Abhik Ghosh Moulick, and Rutika Patel
| | - Anjela Manandhar
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New York, 10314, United States
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, United States
- Present Address: Takeda Pharmaceuticals, Boston, MA, 02139, United States
| | - Sharon M. Loverde
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Boulevard, Staten Island, New York, 10314, United States
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, United States
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, United States
- Ph.D. Program in Physics, The Graduate Center of the City University of New York, New York, NY, 10016, United States
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7
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Cleri F, Giordano S, Blossey R. Nucleosome Array Deformation in Chromatin is Sustained by Bending, Twisting and Kinking of Linker DNA. J Mol Biol 2023; 435:168263. [PMID: 37678705 DOI: 10.1016/j.jmb.2023.168263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 08/21/2023] [Accepted: 08/30/2023] [Indexed: 09/09/2023]
Abstract
Chromatin in the nucleus undergoes mechanical stresses from different sources during the various stages of cell life. Here a trinucleosome array is used as the minimal model to study the mechanical response to applied stress at the molecular level. By using large-scale, all-atom steered-molecular dynamics simulations, we show that the largest part of mechanical stress in compression is accommodated by the DNA linkers joining pairs of nucleosomes, which store the elastic energy accumulated by the applied force. Different mechanical instabilities (Euler bending, Brazier kinking, twist-bending) can deform the DNA canonical structure, as a function of the increasing force load. An important role of the histone tails in assisting the DNA deformation is highlighted. The overall response of the smallest chromatin fragment to compressive stress leaves the nucleosome assembly with a substantial plastic deformation and localised defects, which can have a potential impact on DNA transcription, downstream signaling pathways, the regulation of gene expression, and DNA repair.
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Affiliation(s)
- Fabrizio Cleri
- Université de Lille, Institut d'Electronique Microelectronique et Nanotechnologie (IEMN CNRS UMR8520) and Département de Physique, 59652 Villeneuve d'Ascq, France.
| | - Stefano Giordano
- University of Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520 - IEMN - Institut d'Électronique de Microélectronique et de Nanotechnologie, F-59000 Lille, France
| | - Ralf Blossey
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France
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8
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Shi D, Huang Y, Bai C. Studies of the Mechanism of Nucleosome Dynamics: A Review on Multifactorial Regulation from Computational and Experimental Cases. Polymers (Basel) 2023; 15:polym15071763. [PMID: 37050377 PMCID: PMC10096840 DOI: 10.3390/polym15071763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/28/2023] [Accepted: 03/31/2023] [Indexed: 04/05/2023] Open
Abstract
The nucleosome, which organizes the long coil of genomic DNA in a highly condensed, polymeric way, is thought to be the basic unit of chromosomal structure. As the most important protein–DNA complex, its structural and dynamic features have been successively revealed in recent years. However, its regulatory mechanism, which is modulated by multiple factors, still requires systemic discussion. This study summarizes the regulatory factors of the nucleosome’s dynamic features from the perspective of histone modification, DNA methylation, and the nucleosome-interacting factors (transcription factors and nucleosome-remodeling proteins and cations) and focuses on the research exploring the molecular mechanism through both computational and experimental approaches. The regulatory factors that affect the dynamic features of nucleosomes are also discussed in detail, such as unwrapping, wrapping, sliding, and stacking. Due to the complexity of the high-order topological structures of nucleosomes and the comprehensive effects of regulatory factors, the research on the functional modulation mechanism of nucleosomes has encountered great challenges. The integration of computational and experimental approaches, the construction of physical modes for nucleosomes, and the application of deep learning techniques will provide promising opportunities for further exploration.
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Affiliation(s)
- Danfeng Shi
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong (Shenzhen), Shenzhen 518172, China
- School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| | - Yuxin Huang
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong (Shenzhen), Shenzhen 518172, China
| | - Chen Bai
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong (Shenzhen), Shenzhen 518172, China
- Chenzhu (MoMeD) Biotechnology Co., Ltd., Hangzhou 310005, China
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9
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Sinha S, Pindi C, Ahsan M, Arantes PR, Palermo G. Machines on Genes through the Computational Microscope. J Chem Theory Comput 2023; 19:1945-1964. [PMID: 36947696 PMCID: PMC10104023 DOI: 10.1021/acs.jctc.2c01313] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
Macromolecular machines acting on genes are at the core of life's fundamental processes, including DNA replication and repair, gene transcription and regulation, chromatin packaging, RNA splicing, and genome editing. Here, we report the increasing role of computational biophysics in characterizing the mechanisms of "machines on genes", focusing on innovative applications of computational methods and their integration with structural and biophysical experiments. We showcase how state-of-the-art computational methods, including classical and ab initio molecular dynamics to enhanced sampling techniques, and coarse-grained approaches are used for understanding and exploring gene machines for real-world applications. As this review unfolds, advanced computational methods describe the biophysical function that is unseen through experimental techniques, accomplishing the power of the "computational microscope", an expression coined by Klaus Schulten to highlight the extraordinary capability of computer simulations. Pushing the frontiers of computational biophysics toward a pragmatic representation of large multimegadalton biomolecular complexes is instrumental in bridging the gap between experimentally obtained macroscopic observables and the molecular principles playing at the microscopic level. This understanding will help harness molecular machines for medical, pharmaceutical, and biotechnological purposes.
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10
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Portillo-Ledesma S, Li Z, Schlick T. Genome modeling: From chromatin fibers to genes. Curr Opin Struct Biol 2023; 78:102506. [PMID: 36577295 PMCID: PMC9908845 DOI: 10.1016/j.sbi.2022.102506] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 11/01/2022] [Accepted: 11/06/2022] [Indexed: 12/27/2022]
Abstract
The intricacies of the 3D hierarchical organization of the genome have been approached by many creative modeling studies. The specific model/simulation technique combination defines and restricts the system and phenomena that can be investigated. We present the latest modeling developments and studies of the genome, involving models ranging from nucleosome systems and small polynucleosome arrays to chromatin fibers in the kb-range, chromosomes, and whole genomes, while emphasizing gene folding from first principles. Clever combinations allow the exploration of many interesting phenomena involved in gene regulation, such as nucleosome structure and dynamics, nucleosome-nucleosome stacking, polynucleosome array folding, protein regulation of chromatin architecture, mechanisms of gene folding, loop formation, compartmentalization, and structural transitions at the chromosome and genome levels. Gene-level modeling with full details on nucleosome positions, epigenetic factors, and protein binding, in particular, can in principle be scaled up to model chromosomes and cells to study fundamental biological regulation.
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Affiliation(s)
- Stephanie Portillo-Ledesma
- Department of Chemistry, New York University, 100 Washington Square East, Silver Building, New York, 10003, NY, USA
| | - Zilong Li
- Department of Chemistry, New York University, 100 Washington Square East, Silver Building, New York, 10003, NY, USA
| | - Tamar Schlick
- Department of Chemistry, New York University, 100 Washington Square East, Silver Building, New York, 10003, NY, USA; Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, 10012, NY, USA; New York University-East China Normal University Center for Computational Chemistry, New York University Shanghai, Room 340, Geography Building, 3663 North Zhongshan Road, Shanghai, 200122, China; Simons Center for Computational Physical Chemistry, 24 Waverly Place, Silver Building, New York University, New York, 10003, NY, USA.
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11
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MacCarthy CM, Huertas J, Ortmeier C, Vom Bruch H, Tan DS, Reinke D, Sander A, Bergbrede T, Jauch R, Schöler HR, Cojocaru V. OCT4 interprets and enhances nucleosome flexibility. Nucleic Acids Res 2022; 50:10311-10327. [PMID: 36130732 PMCID: PMC9561370 DOI: 10.1093/nar/gkac755] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 07/28/2022] [Accepted: 08/24/2022] [Indexed: 01/06/2023] Open
Abstract
Pioneer transcription factors are proteins that induce cellular identity transitions by binding to inaccessible regions of DNA in nuclear chromatin. They contribute to chromatin opening and recruit other factors to regulatory DNA elements. The structural features and dynamics modulating their interaction with nucleosomes are still unresolved. From a combination of experiments and molecular simulations, we reveal here how the pioneer factor and master regulator of pluripotency, Oct4, interprets and enhances nucleosome structural flexibility. The magnitude of Oct4’s impact on nucleosome dynamics depends on the binding site position and the mobility of the unstructured tails of nucleosomal histone proteins. Oct4 uses both its DNA binding domains to propagate and stabilize open nucleosome conformations, one for specific sequence recognition and the other for nonspecific interactions with nearby regions of DNA. Our findings provide a structural basis for the versatility of transcription factors in engaging with nucleosomes and have implications for understanding how pioneer factors induce chromatin dynamics.
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Affiliation(s)
- Caitlin M MacCarthy
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Jan Huertas
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany.,Yusuf Hamied Department of Chemistry, University of Cambridge, UK
| | - Claudia Ortmeier
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Hermann Vom Bruch
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Daisylyn Senna Tan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China
| | - Deike Reinke
- Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Astrid Sander
- Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | | | - Ralf Jauch
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China
| | - Hans R Schöler
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany.,Medical Faculty, University of Münster, Germany
| | - Vlad Cojocaru
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany.,Computational Structural Biology Group, University of Utrecht, The Netherlands.,STAR-UBB Institute, Babeş-Bolyai University, Cluj-Napoca, Romania
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12
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H2A-H2B Histone Dimer Plasticity and Its Functional Implications. Cells 2022; 11:cells11182837. [PMID: 36139412 PMCID: PMC9496766 DOI: 10.3390/cells11182837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/01/2022] [Accepted: 09/06/2022] [Indexed: 12/04/2022] Open
Abstract
The protein core of the nucleosome is composed of an H3-H4 histone tetramer and two H2A-H2B histone dimers. The tetramer organizes the central 60 DNA bp, while H2A-H2B dimers lock the flanking DNA segments. Being positioned at the sides of the nucleosome, H2A-H2B dimers stabilize the overall structure of the nucleosome and modulate its dynamics, such as DNA unwrapping, sliding, etc. Such modulation at the epigenetic level is achieved through post-translational modifications and the incorporation of histone variants. However, the detailed connection between the sequence of H2A-H2B histones and their structure, dynamics and implications for nucleosome functioning remains elusive. In this work, we present a detailed study of H2A-H2B dimer dynamics in the free form and in the context of nucleosomes via atomistic molecular dynamics simulations (based on X. laevis histones). We supplement simulation results by comparative analysis of information in the structural databases. Particularly, we describe a major dynamical mode corresponding to the bending movement of the longest H2A and H2B α-helices. This overall bending dynamics of the H2A-H2B dimer were found to be modulated by its interactions with DNA, H3-H4 tetramer, the presence of DNA twist-defects with nucleosomal DNA and the amino acid sequence of histones. Taken together, our results shed new light on the dynamical mechanisms of nucleosome functioning, such as nucleosome sliding, DNA-unwrapping and their epigenetic modulation.
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13
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Tsunaka Y, Furukawa A, Nishimura Y. Histone tail network and modulation in a nucleosome. Curr Opin Struct Biol 2022; 75:102436. [PMID: 35863166 DOI: 10.1016/j.sbi.2022.102436] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/17/2022] [Accepted: 06/17/2022] [Indexed: 11/18/2022]
Abstract
The structural unit of eukaryotic chromatin is a nucleosome, comprising two histone H2A/H2B heterodimers and one histone (H3/H4)2 tetramer, wrapped around by ∼146-bp core DNA and linker DNA. Flexible histone tails sticking out from the core undergo posttranslational modifications that are responsible for various epigenetic functions. Recently, the functional dynamics of histone tails and their modulation within the nucleosome and nucleosomal complexes have been investigated by integrating NMR, molecular dynamics simulations, and cryo-electron microscopy approaches. In particular, recent NMR studies have revealed correlations in the structures of histone N-terminal tails between H2A and H2B, as well as between H3 and H4 depending on linker DNA, suggesting that histone tail networks exist even within the nucleosome.
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Affiliation(s)
- Yasuo Tsunaka
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Ayako Furukawa
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Yoshifumi Nishimura
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan; Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739-8528, Japan.
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14
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Shi X, Zhai Z, Chen Y, Li J, Nordenskiöld L. Recent Advances in Investigating Functional Dynamics of Chromatin. Front Genet 2022; 13:870640. [PMID: 35450211 PMCID: PMC9017861 DOI: 10.3389/fgene.2022.870640] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/11/2022] [Indexed: 11/26/2022] Open
Abstract
Dynamics spanning the picosecond-minute time domain and the atomic-subcellular spatial window have been observed for chromatin in vitro and in vivo. The condensed organization of chromatin in eukaryotic cells prevents regulatory factors from accessing genomic DNA, which requires dynamic stabilization and destabilization of structure to initiate downstream DNA activities. Those processes are achieved through altering conformational and dynamic properties of nucleosomes and nucleosome–protein complexes, of which delineating the atomistic pictures is essential to understand the mechanisms of chromatin regulation. In this review, we summarize recent progress in determining chromatin dynamics and their modulations by a number of factors including post-translational modifications (PTMs), incorporation of histone variants, and binding of effector proteins. We focus on experimental observations obtained using high-resolution techniques, primarily including nuclear magnetic resonance (NMR) spectroscopy, Förster (or fluorescence) resonance energy transfer (FRET) microscopy, and molecular dynamics (MD) simulations, and discuss the elucidated dynamics in the context of functional response and relevance.
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Affiliation(s)
- Xiangyan Shi
- Department of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Ziwei Zhai
- Department of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Yinglu Chen
- Department of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Jindi Li
- Department of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Lars Nordenskiöld
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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15
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Huertas J, Woods EJ, Collepardo-Guevara R. Multiscale modelling of chromatin organisation: Resolving nucleosomes at near-atomistic resolution inside genes. Curr Opin Cell Biol 2022; 75:102067. [DOI: 10.1016/j.ceb.2022.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/24/2022] [Accepted: 02/04/2022] [Indexed: 12/15/2022]
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16
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Safaric B, Chacin E, Scherr MJ, Rajappa L, Gebhardt C, Kurat CF, Cordes T, Duderstadt KE. The fork protection complex recruits FACT to reorganize nucleosomes during replication. Nucleic Acids Res 2022; 50:1317-1334. [PMID: 35061899 PMCID: PMC8860610 DOI: 10.1093/nar/gkac005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 12/21/2021] [Accepted: 01/05/2022] [Indexed: 01/14/2023] Open
Abstract
Chromosome replication depends on efficient removal of nucleosomes by accessory factors to ensure rapid access to genomic information. Here, we show this process requires recruitment of the nucleosome reorganization activity of the histone chaperone FACT. Using single-molecule FRET, we demonstrate that reorganization of nucleosomal DNA by FACT requires coordinated engagement by the middle and C-terminal domains of Spt16 and Pob3 but does not require the N-terminus of Spt16. Using structure-guided pulldowns, we demonstrate instead that the N-terminal region is critical for recruitment by the fork protection complex subunit Tof1. Using in vitro chromatin replication assays, we confirm the importance of these interactions for robust replication. Our findings support a mechanism in which nucleosomes are removed through the coordinated engagement of multiple FACT domains positioned at the replication fork by the fork protection complex.
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Affiliation(s)
- Barbara Safaric
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Erika Chacin
- Biomedical Center (BMC), Division of Molecular Biology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, 82152 Planegg, Germany
| | - Matthias J Scherr
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Lional Rajappa
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Christian Gebhardt
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany
| | - Christoph F Kurat
- Biomedical Center (BMC), Division of Molecular Biology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, 82152 Planegg, Germany
| | - Thorben Cordes
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany
| | - Karl E Duderstadt
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.,Physics Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
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17
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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: 269] [Impact Index Per Article: 134.5] [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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18
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Fu I, Geacintov NE, Broyde S. Molecular dynamics simulations reveal how H3K56 acetylation impacts nucleosome structure to promote DNA exposure for lesion sensing. DNA Repair (Amst) 2021; 107:103201. [PMID: 34399316 PMCID: PMC8526387 DOI: 10.1016/j.dnarep.2021.103201] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/12/2021] [Accepted: 08/02/2021] [Indexed: 01/04/2023]
Abstract
The first order of DNA packaging is the nucleosome with the DNA wrapped around the histone octamer. This leaves the nucleosomal DNA with access restrictions, which impose a significant barrier to repair of damaged DNA. The efficiency of DNA repair has been related to nucleosome structure and chromatin status, which is modulated in part by post-translational modifications (PTMs) of histones. Numerous studies have suggested a role for acetylation of lysine at position 56 of the H3 histone (H3K56ac) in various DNA transactions, including the response to DNA damage and its association with human cancer. Biophysical studies have revealed that H3K56ac increases DNA accessibility by facilitating spontaneous and transient unwrapping motions of the DNA ends. However, how this acetylation mark modulates nucleosome structure and dynamics to promote accessibility to the damaged DNA for repair factors and other proteins is still poorly understood. Here, we utilize approximately 5-6 microseconds of atomistic molecular dynamics simulations to delineate the impact of H3K56 acetylation on the nucleosome structure and dynamics, and to elucidate how these nucleosome properties are further impacted when a bulky benzo[a]pyrene-derived DNA lesion is placed near the acetylation site. Our findings reveal that H3K56ac alone induces considerable disturbance to the histone-DNA/histone-histone interactions, and amplifies the distortions imposed by the presence of the lesion. Our work highlights the important role of H3K56 acetylation in response to DNA damage and depicts how access to DNA lesions by the repair machinery can be facilitated within the nucleosome via a key acetylation event.
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Affiliation(s)
- Iwen Fu
- Department of Biology, New York University, 100 Washington Square East, New York, NY, 10003, United States.
| | - Nicholas E Geacintov
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY, 10003, United States.
| | - Suse Broyde
- Department of Biology, New York University, 100 Washington Square East, New York, NY, 10003, United States.
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19
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Kumar A, Chan J, Taguchi M, Kono H. Interplay among transacting factors around promoter in the initial phases of transcription. Curr Opin Struct Biol 2021; 71:7-15. [PMID: 34111671 DOI: 10.1016/j.sbi.2021.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/20/2021] [Accepted: 04/27/2021] [Indexed: 10/21/2022]
Abstract
The initiation signals are raised around the promoter by one of the general transcription factors, triggering a sequence of events that lead to mRNA transcript formation from target genes. Both specific noncoding DNA regions and transacting, macromolecular assemblies are intricately involved and indispensable. The transition between the subsequent transcriptional stages is accompanied by stage-specific signals and structural changes in the macromolecular assemblies and facilitated by the recruitment/removal of other chromatin and transcription-associated elements. Here, we discuss the choreography of transacting factors around promoter in the establishment and effectuation of the initial phases of transcription such as NDR formation, +1 nucleosome positioning, promoter DNA opening, and RNAPII promoter escape from a structural viewpoint.
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Affiliation(s)
- Amarjeet Kumar
- Molecular Modeling and Simulation Group, Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology, 8-1-7 Umemidai, Kizugawa, Kyoto, 619-0215, Japan
| | - Justin Chan
- Molecular Modeling and Simulation Group, Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology, 8-1-7 Umemidai, Kizugawa, Kyoto, 619-0215, Japan
| | - Masahiko Taguchi
- Molecular Modeling and Simulation Group, Institute for Quantum Life Science, 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, Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology, 8-1-7 Umemidai, Kizugawa, Kyoto, 619-0215, Japan.
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20
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Huertas J, Schöler HR, Cojocaru V. Histone tails cooperate to control the breathing of genomic nucleosomes. PLoS Comput Biol 2021; 17:e1009013. [PMID: 34081696 PMCID: PMC8174689 DOI: 10.1371/journal.pcbi.1009013] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 04/28/2021] [Indexed: 11/19/2022] Open
Abstract
Genomic DNA is packaged in chromatin, a dynamic fiber variable in size and compaction. In chromatin, repeating nucleosome units wrap 145–147 DNA basepairs around histone proteins. Genetic and epigenetic regulation of genes relies on structural transitions in chromatin which are driven by intra- and inter-nucleosome dynamics and modulated by chemical modifications of the unstructured terminal tails of histones. Here we demonstrate how the interplay between histone H3 and H2A tails control ample nucleosome breathing motions. We monitored large openings of two genomic nucleosomes, and only moderate breathing of an engineered nucleosome in atomistic molecular simulations amounting to 24 μs. Transitions between open and closed nucleosome conformations were mediated by the displacement and changes in compaction of the two histone tails. These motions involved changes in the DNA interaction profiles of clusters of epigenetic regulatory aminoacids in the tails. Removing the histone tails resulted in a large increase of the amplitude of nucleosome breathing but did not change the sequence dependent pattern of the motions. Histone tail modulated nucleosome breathing is a key mechanism of chromatin dynamics with important implications for epigenetic regulation. In the cell, the DNA is packed in chromatin. Chromatin is a highly dynamic fiber structure made of arrays of nucleosomes with different degrees of compaction. Each nucleosome has 145–147 basepairs of DNA wrapped around a protein octamer made of four unique histone proteins. Each histone is present twice and has a structured part and one or two disordered terminal tails. The regulation of gene expression in the cell and during cellular transitions depends on dynamic changes in chromatin structure. Chromatin dynamics are modulated by intra and inter nucleosome motions and by posttranslational chemical modifications of the histone tails. Here we reveal how histone tails control the intra nucleosome dynamics at atomic resolution. From extensive sampling of nucleosome dynamics in atomistic molecular simulations, we show that genomic nucleosomes breath more extensively than engineered ones and we describe how two histone tails cooperate to control nucleosome breathing through interactions between clusters of positively charged residues and the DNA. Nucleosome conformations with different degrees of opening are associated with different conformations, positions, and DNA interaction patterns of the tails. With this mechanism, we contribute to the understanding of chromatin dynamics at atomic resolution.
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Affiliation(s)
- Jan Huertas
- In Silico Biomolecular Structure and Dynamics Group, Hubrecht Institute, Utrecht, The Netherlands
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Center for Multiscale Theory and Computation, Westfälische Wilhelms University, Münster, Germany
| | - Hans Robert Schöler
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Medical Faculty, University of Münster, Münster, Germany
| | - Vlad Cojocaru
- In Silico Biomolecular Structure and Dynamics Group, Hubrecht Institute, Utrecht, The Netherlands
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Center for Multiscale Theory and Computation, Westfälische Wilhelms University, Münster, Germany
- * E-mail: ,
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21
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Histone dynamics mediate DNA unwrapping and sliding in nucleosomes. Nat Commun 2021; 12:2387. [PMID: 33888707 PMCID: PMC8062685 DOI: 10.1038/s41467-021-22636-9] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/23/2021] [Indexed: 02/06/2023] Open
Abstract
Nucleosomes are elementary building blocks of chromatin in eukaryotes. They tightly wrap ∼147 DNA base pairs around an octamer of histone proteins. How nucleosome structural dynamics affect genome functioning is not completely clear. Here we report all-atom molecular dynamics simulations of nucleosome core particles at a timescale of 15 microseconds. At this timescale, functional modes of nucleosome dynamics such as spontaneous nucleosomal DNA breathing, unwrapping, twisting, and sliding were observed. We identified atomistic mechanisms of these processes by analyzing the accompanying structural rearrangements of the histone octamer and histone-DNA contacts. Octamer dynamics and plasticity were found to enable DNA unwrapping and sliding. Through multi-scale modeling, we showed that nucleosomal DNA dynamics contribute to significant conformational variability of the chromatin fiber at the supranucleosomal level. Our study further supports mechanistic coupling between fine details of histone dynamics and chromatin functioning, provides a framework for understanding the effects of various chromatin modifications.
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22
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Dalal Y, Panchenko AR. Diving into Chromatin across Space and Time. J Mol Biol 2021; 433:166884. [PMID: 33621519 DOI: 10.1016/j.jmb.2021.166884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Yamini Dalal
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, United States.
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