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Song A, Wang Y, Liu C, Yu J, Zhang Z, Lan L, Lin H, Zhao J, Li G. Replication-coupled inheritance of chromatin states. CELL INSIGHT 2024; 3:100195. [PMID: 39391004 PMCID: PMC11462216 DOI: 10.1016/j.cellin.2024.100195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 08/05/2024] [Accepted: 08/05/2024] [Indexed: 10/12/2024]
Abstract
During the development of eukaryote, faithful inheritance of chromatin states is central to the maintenance of cell fate. DNA replication poses a significant challenge for chromatin state inheritance because every nucleosome in the genome is disrupted as the replication fork passes. It has been found that many factors including DNA polymerases, histone chaperones, as well as, RNA Pol II and histone modifying enzymes coordinate spatially and temporally to maintain the epigenome during this progress. In this review, we provide a summary of the detailed mechanisms of replication-coupled nucleosome assembly and post-replication chromatin maturation, highlight the inheritance of chromatin states and epigenome during these processes, and discuss the future directions and challenges in this field.
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Affiliation(s)
- Aoqun Song
- New Cornerstone Science Laboratory, Frontier Science Center for Immunology and Metabolism, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan, 430072, China
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yunting Wang
- New Cornerstone Science Laboratory, Frontier Science Center for Immunology and Metabolism, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan, 430072, China
| | - Cuifang Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, 100101, China
| | - Juan Yu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zixu Zhang
- New Cornerstone Science Laboratory, Frontier Science Center for Immunology and Metabolism, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan, 430072, China
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Liting Lan
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Haiyan Lin
- New Cornerstone Science Laboratory, Frontier Science Center for Immunology and Metabolism, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan, 430072, China
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jicheng Zhao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, 100101, China
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, 266021, China
| | - Guohong Li
- New Cornerstone Science Laboratory, Frontier Science Center for Immunology and Metabolism, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan, 430072, China
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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2
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Hong Y, Ye F, Gao X, Inman JT, Wang MD. Tunable Elliptical Cylinders for Rotational Mechanical Studies of Single DNA Molecules. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.25.614944. [PMID: 39386461 PMCID: PMC11463624 DOI: 10.1101/2024.09.25.614944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/12/2024]
Abstract
The angular optical trap (AOT) is a powerful technique for measuring the DNA topology and rotational mechanics of fundamental biological processes. Realizing the full potential of the AOT requires rapid torsional control of these processes. However, existing AOT quartz cylinders are limited in their ability to meet the high rotation rate requirement while minimizing laser-induced photodamage. In this work, we present a novel trapping particle design to meet this challenge by creating small metamaterial elliptical cylinders with tunable trapping force and torque properties. The optical torque of these cylinders arises from their shape anisotropy, with their optical properties tuned via multilayered SiO 2 and Si 3 N 4 deposition. We demonstrate that these cylinders can be rotated at about 3 times the rate of quartz cylinders without slippage while enhancing the torque measurement resolution during DNA torsional elasticity studies. This approach opens new opportunities for previously inaccessible rotational studies of DNA processing.
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3
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Ashokkumar M, Mei W, Peterson JJ, Harigaya Y, Murdoch DM, Margolis DM, Kornfein C, Oesterling A, Guo Z, Rudin CD, Jiang Y, Browne EP. Integrated Single-cell Multiomic Analysis of HIV Latency Reversal Reveals Novel Regulators of Viral Reactivation. GENOMICS, PROTEOMICS & BIOINFORMATICS 2024; 22:qzae003. [PMID: 38902848 PMCID: PMC11189801 DOI: 10.1093/gpbjnl/qzae003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 10/19/2023] [Indexed: 06/22/2024]
Abstract
Despite the success of antiretroviral therapy, human immunodeficiency virus (HIV) cannot be cured because of a reservoir of latently infected cells that evades therapy. To understand the mechanisms of HIV latency, we employed an integrated single-cell RNA sequencing (scRNA-seq) and single-cell assay for transposase-accessible chromatin with sequencing (scATAC-seq) approach to simultaneously profile the transcriptomic and epigenomic characteristics of ∼ 125,000 latently infected primary CD4+ T cells after reactivation using three different latency reversing agents. Differentially expressed genes and differentially accessible motifs were used to examine transcriptional pathways and transcription factor (TF) activities across the cell population. We identified cellular transcripts and TFs whose expression/activity was correlated with viral reactivation and demonstrated that a machine learning model trained on these data was 75%-79% accurate at predicting viral reactivation. Finally, we validated the role of two candidate HIV-regulating factors, FOXP1 and GATA3, in viral transcription. These data demonstrate the power of integrated multimodal single-cell analysis to uncover novel relationships between host cell factors and HIV latency.
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Affiliation(s)
- Manickam Ashokkumar
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- HIV Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Wenwen Mei
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jackson J Peterson
- HIV Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Yuriko Harigaya
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - David M Murdoch
- Department of Medicine, Duke University, Durham, NC 27708, USA
| | - David M Margolis
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- HIV Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Caleb Kornfein
- Department of Computer Science, Duke University, Durham, NC 27708, USA
| | - Alex Oesterling
- Department of Computer Science, Duke University, Durham, NC 27708, USA
| | - Zhicheng Guo
- Department of Computer Science, Duke University, Durham, NC 27708, USA
| | - Cynthia D Rudin
- Department of Computer Science, Duke University, Durham, NC 27708, USA
| | - Yuchao Jiang
- Department of Statistics, Texas A&M University, College Station, TX 77843, USA
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Edward P Browne
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- HIV Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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4
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Oyarzún-Cisterna A, Gidi C, Raiqueo F, Amigo R, Rivas C, Torrejón M, Gutiérrez JL. General regulatory factors exert differential effects on nucleosome sliding activity of the ISW1a complex. Biol Res 2024; 57:22. [PMID: 38704609 PMCID: PMC11069190 DOI: 10.1186/s40659-024-00500-6] [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: 01/28/2024] [Accepted: 04/15/2024] [Indexed: 05/06/2024] Open
Abstract
BACKGROUND Chromatin dynamics is deeply involved in processes that require access to DNA, such as transcriptional regulation. Among the factors involved in chromatin dynamics at gene regulatory regions are general regulatory factors (GRFs). These factors contribute to establishment and maintenance of nucleosome-depleted regions (NDRs). These regions are populated by nucleosomes through histone deposition and nucleosome sliding, the latter catalyzed by a number of ATP-dependent chromatin remodeling complexes, including ISW1a. It has been observed that GRFs can act as barriers against nucleosome sliding towards NDRs. However, the relative ability of the different GRFs to hinder sliding activity is currently unknown. RESULTS Considering this, we performed a comparative analysis for the main GRFs, with focus in their ability to modulate nucleosome sliding mediated by ISW1a. Among the GRFs tested in nucleosome remodeling assays, Rap1 was the only factor displaying the ability to hinder the activity of ISW1a. This effect requires location of the Rap1 cognate sequence on linker that becomes entry DNA in the nucleosome remodeling process. In addition, Rap1 was able to hinder nucleosome assembly in octamer transfer assays. Concurrently, Rap1 displayed the highest affinity for and longest dwell time from its target sequence, compared to the other GRFs tested. Consistently, through bioinformatics analyses of publicly available genome-wide data, we found that nucleosome occupancy and histone deposition in vivo are inversely correlated with the affinity of Rap1 for its target sequences in the genome. CONCLUSIONS Our findings point to DNA binding affinity, residence time and location at particular translational positions relative to the nucleosome core as the key features of GRFs underlying their roles played in nucleosome sliding and assembly.
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Affiliation(s)
- Andrea Oyarzún-Cisterna
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, 4070043, Concepción, Chile
| | - Cristián Gidi
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, 4070043, Concepción, Chile
| | - Fernanda Raiqueo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, 4070043, Concepción, Chile
| | - Roberto Amigo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, 4070043, Concepción, Chile
| | - Camila Rivas
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, 4070043, Concepción, Chile
| | - Marcela Torrejón
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, 4070043, Concepción, Chile
| | - José L Gutiérrez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, 4070043, Concepción, Chile.
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5
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Eustermann S, Patel AB, Hopfner KP, He Y, Korber P. Energy-driven genome regulation by ATP-dependent chromatin remodellers. Nat Rev Mol Cell Biol 2024; 25:309-332. [PMID: 38081975 DOI: 10.1038/s41580-023-00683-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2023] [Indexed: 03/28/2024]
Abstract
The packaging of DNA into chromatin in eukaryotes regulates gene transcription, DNA replication and DNA repair. ATP-dependent chromatin remodelling enzymes (re)arrange nucleosomes at the first level of chromatin organization. Their Snf2-type motor ATPases alter histone-DNA interactions through a common DNA translocation mechanism. Whether remodeller activities mainly catalyse nucleosome dynamics or accurately co-determine nucleosome organization remained unclear. In this Review, we discuss the emerging mechanisms of chromatin remodelling: dynamic remodeller architectures and their interactions, the inner workings of the ATPase cycle, allosteric regulation and pathological dysregulation. Recent mechanistic insights argue for a decisive role of remodellers in the energy-driven self-organization of chromatin, which enables both stability and plasticity of genome regulation - for example, during development and stress. Different remodellers, such as members of the SWI/SNF, ISWI, CHD and INO80 families, process (epi)genetic information through specific mechanisms into distinct functional outputs. Combinatorial assembly of remodellers and their interplay with histone modifications, histone variants, DNA sequence or DNA-bound transcription factors regulate nucleosome mobilization or eviction or histone exchange. Such input-output relationships determine specific nucleosome positions and compositions with distinct DNA accessibilities and mediate differential genome regulation. Finally, remodeller genes are often mutated in diseases characterized by genome dysregulation, notably in cancer, and we discuss their physiological relevance.
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Affiliation(s)
- Sebastian Eustermann
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Avinash B Patel
- Department of Molecular Biosciences, Robert H. Lurie Comprehensive Cancer Center, Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
| | - Karl-Peter Hopfner
- Gene Center and Department of Biochemistry, Faculty of Chemistry and Pharmacy, LMU Munich, Munich, Germany
| | - Yuan He
- Department of Molecular Biosciences, Robert H. Lurie Comprehensive Cancer Center, Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA.
| | - Philipp Korber
- Biomedical Center (BMC), Molecular Biology, Faculty of Medicine, LMU Munich, Martinsried, Germany.
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6
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Dreier MR, Walia J, de la Serna IL. Targeting SWI/SNF Complexes in Cancer: Pharmacological Approaches and Implications. EPIGENOMES 2024; 8:7. [PMID: 38390898 PMCID: PMC10885108 DOI: 10.3390/epigenomes8010007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/28/2024] [Accepted: 01/31/2024] [Indexed: 02/24/2024] Open
Abstract
SWI/SNF enzymes are heterogeneous multi-subunit complexes that utilize the energy from ATP hydrolysis to remodel chromatin structure, facilitating transcription, DNA replication, and repair. In mammalian cells, distinct sub-complexes, including cBAF, ncBAF, and PBAF exhibit varying subunit compositions and have different genomic functions. Alterations in the SWI/SNF complex and sub-complex functions are a prominent feature in cancer, making them attractive targets for therapeutic intervention. Current strategies in cancer therapeutics involve the use of pharmacological agents designed to bind and disrupt the activity of SWI/SNF complexes or specific sub-complexes. Inhibitors targeting the catalytic subunits, SMARCA4/2, and small molecules binding SWI/SNF bromodomains are the primary approaches for suppressing SWI/SNF function. Proteolysis-targeting chimeras (PROTACs) were generated by the covalent linkage of the bromodomain or ATPase-binding ligand to an E3 ligase-binding moiety. This engineered connection promotes the degradation of specific SWI/SNF subunits, enhancing and extending the impact of this pharmacological intervention in some cases. Extensive preclinical studies have underscored the therapeutic potential of these drugs across diverse cancer types. Encouragingly, some of these agents have progressed from preclinical research to clinical trials, indicating a promising stride toward the development of effective cancer therapeutics targeting SWI/SNF complex and sub-complex functions.
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Affiliation(s)
- Megan R Dreier
- Department of Cell and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3000 Arlington Ave, Toledo 43614, OH, USA
| | - Jasmine Walia
- Department of Cell and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3000 Arlington Ave, Toledo 43614, OH, USA
| | - Ivana L de la Serna
- Department of Cell and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3000 Arlington Ave, Toledo 43614, OH, USA
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7
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Meeussen JVW, Lenstra TL. Time will tell: comparing timescales to gain insight into transcriptional bursting. Trends Genet 2024; 40:160-174. [PMID: 38216391 PMCID: PMC10860890 DOI: 10.1016/j.tig.2023.11.003] [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: 09/13/2023] [Revised: 11/27/2023] [Accepted: 11/27/2023] [Indexed: 01/14/2024]
Abstract
Recent imaging studies have captured the dynamics of regulatory events of transcription inside living cells. These events include transcription factor (TF) DNA binding, chromatin remodeling and modification, enhancer-promoter (E-P) proximity, cluster formation, and preinitiation complex (PIC) assembly. Together, these molecular events culminate in stochastic bursts of RNA synthesis, but their kinetic relationship remains largely unclear. In this review, we compare the timescales of upstream regulatory steps (input) with the kinetics of transcriptional bursting (output) to generate mechanistic models of transcription dynamics in single cells. We highlight open questions and potential technical advances to guide future endeavors toward a quantitative and kinetic understanding of transcription regulation.
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Affiliation(s)
- Joseph V W Meeussen
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, Amsterdam 1066CX, The Netherlands
| | - Tineke L Lenstra
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, Amsterdam 1066CX, The Netherlands.
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8
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Lee J, Wu M, Inman JT, Singh G, Park SH, Lee JH, Fulbright RM, Hong Y, Jeong J, Berger JM, Wang MD. Chromatinization modulates topoisomerase II processivity. Nat Commun 2023; 14:6844. [PMID: 37891161 PMCID: PMC10611788 DOI: 10.1038/s41467-023-42600-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
Type IIA topoisomerases are essential DNA processing enzymes that must robustly and reliably relax DNA torsional stress. While cellular processes constantly create varying torsional stress, how this variation impacts type IIA topoisomerase function remains obscure. Using multiple single-molecule approaches, we examined the torsional dependence of eukaryotic topoisomerase II (topo II) activity on naked DNA and chromatin. We observed that topo II is ~50-fold more processive on buckled DNA than previously estimated. We further discovered that topo II relaxes supercoiled DNA prior to plectoneme formation, but with processivity reduced by ~100-fold. This relaxation decreases with diminishing torsion, consistent with topo II capturing transient DNA loops. Topo II retains high processivity on buckled chromatin (~10,000 turns) and becomes highly processive even on chromatin under low torsional stress (~1000 turns), consistent with chromatin's predisposition to readily form DNA crossings. This work establishes that chromatin is a major stimulant of topo II function.
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Affiliation(s)
- Jaeyoon Lee
- Physics Department & LASSP, Cornell University, Ithaca, NY, 14853, USA
| | - Meiling Wu
- Physics Department & LASSP, Cornell University, Ithaca, NY, 14853, USA
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY, 14853, USA
| | - James T Inman
- Physics Department & LASSP, Cornell University, Ithaca, NY, 14853, USA
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY, 14853, USA
| | - Gundeep Singh
- Biophysics Program, Cornell University, Ithaca, NY, 14853, USA
| | - Seong Ha Park
- Biophysics Program, Cornell University, Ithaca, NY, 14853, USA
| | - Joyce H Lee
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | | | - Yifeng Hong
- Department of Electrical and Computer Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Joshua Jeong
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - James M Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Michelle D Wang
- Physics Department & LASSP, Cornell University, Ithaca, NY, 14853, USA.
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY, 14853, USA.
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9
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Amigo R, Raiqueo F, Tarifeño E, Farkas C, Gutiérrez JL. Poly(dA:dT) Tracts Differentially Modulate Nucleosome Remodeling Activity of RSC and ISW1a Complexes, Exerting Tract Orientation-Dependent and -Independent Effects. Int J Mol Sci 2023; 24:15245. [PMID: 37894925 PMCID: PMC10607297 DOI: 10.3390/ijms242015245] [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: 08/16/2023] [Revised: 09/27/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023] Open
Abstract
The establishment and maintenance of nucleosome-free regions (NFRs) are prominent processes within chromatin dynamics. Transcription factors, ATP-dependent chromatin remodeling complexes (CRCs) and DNA sequences are the main factors involved. In Saccharomyces cerevisiae, CRCs such as RSC contribute to chromatin opening at NFRs, while other complexes, including ISW1a, contribute to NFR shrinking. Regarding DNA sequences, growing evidence points to poly(dA:dT) tracts as playing a direct role in active processes involved in nucleosome positioning dynamics. Intriguingly, poly(dA:dT)-tract-containing NFRs span asymmetrically relative to the location of the tract by a currently unknown mechanism. In order to obtain insight into the role of poly(dA:dT) tracts in nucleosome remodeling, we performed a systematic analysis of their influence on the activity of ISW1a and RSC complexes. Our results show that poly(dA:dT) tracts differentially affect the activity of these CRCs. Moreover, we found differences between the effects exerted by the two alternative tract orientations. Remarkably, tract-containing linker DNA is taken as exit DNA for nucleosome sliding catalyzed by RSC. Our findings show that defined DNA sequences, when present in linker DNA, can dictate in which direction a remodeling complex has to slide nucleosomes and shed light into the mechanisms underlying asymmetrical chromatin opening around poly(dA:dT) tracts.
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Affiliation(s)
- Roberto Amigo
- Laboratory of Transcriptional Regulation, Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción, Concepción 4070043, Chile; (R.A.); (F.R.); (E.T.)
| | - Fernanda Raiqueo
- Laboratory of Transcriptional Regulation, Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción, Concepción 4070043, Chile; (R.A.); (F.R.); (E.T.)
| | - Estefanía Tarifeño
- Laboratory of Transcriptional Regulation, Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción, Concepción 4070043, Chile; (R.A.); (F.R.); (E.T.)
| | - Carlos Farkas
- Biomedical Sciences Research Laboratory, Department of Basic Sciences and Morphology, Faculty of Medicine, Universidad Católica de la Santísima Concepción, Concepción 4090541, Chile;
| | - José L. Gutiérrez
- Laboratory of Transcriptional Regulation, Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción, Concepción 4070043, Chile; (R.A.); (F.R.); (E.T.)
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10
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Abstract
Cells must tightly regulate their gene expression programs and yet rapidly respond to acute biochemical and biophysical cues within their environment. This information is transmitted to the nucleus through various signaling cascades, culminating in the activation or repression of target genes. Transcription factors (TFs) are key mediators of these signals, binding to specific regulatory elements within chromatin. While live-cell imaging has conclusively proven that TF-chromatin interactions are highly dynamic, how such transient interactions can have long-term impacts on developmental trajectories and disease progression is still largely unclear. In this review, we summarize our current understanding of the dynamic nature of TF functions, starting with a historical overview of early live-cell experiments. We highlight key factors that govern TF dynamics and how TF dynamics, in turn, affect downstream transcriptional bursting. Finally, we conclude with open challenges and emerging technologies that will further our understanding of transcriptional regulation.
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Affiliation(s)
- Kaustubh Wagh
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA; , ,
- Department of Physics, University of Maryland, College Park, Maryland, USA;
| | - Diana A Stavreva
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA; , ,
| | - Arpita Upadhyaya
- Department of Physics, University of Maryland, College Park, Maryland, USA;
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland, USA
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA; , ,
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11
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Lee J, Wu M, Inman JT, Singh G, Park SH, Lee JH, Fulbright RM, Hong Y, Jeong J, Berger JM, Wang MD. Chromatinization Modulates Topoisomerase II Processivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.03.560726. [PMID: 37873421 PMCID: PMC10592930 DOI: 10.1101/2023.10.03.560726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Type IIA topoisomerases are essential DNA processing enzymes that must robustly and reliably relax DNA torsional stress in vivo. While cellular processes constantly create different degrees of torsional stress, how this stress feeds back to control type IIA topoisomerase function remains obscure. Using a suite of single-molecule approaches, we examined the torsional impact on supercoiling relaxation of both naked DNA and chromatin by eukaryotic topoisomerase II (topo II). We observed that topo II was at least ~ 50-fold more processive on plectonemic DNA than previously estimated, capable of relaxing > 6000 turns. We further discovered that topo II could relax supercoiled DNA prior to plectoneme formation, but with a ~100-fold reduction in processivity; strikingly, the relaxation rate in this regime decreased with diminishing torsion in a manner consistent with the capture of transient DNA loops by topo II. Chromatinization preserved the high processivity of the enzyme under high torsional stress. Interestingly, topo II was still highly processive (~ 1000 turns) even under low torsional stress, consistent with the predisposition of chromatin to readily form DNA crossings. This work establishes that chromatin is a major stimulant of topo II function, capable of enhancing function even under low torsional stress.
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Affiliation(s)
- Jaeyoon Lee
- Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - Meiling Wu
- Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA
| | - James T. Inman
- Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA
| | - Gundeep Singh
- Biophysics Program, Cornell University, Ithaca, NY 14853, USA
| | - Seong ha Park
- Biophysics Program, Cornell University, Ithaca, NY 14853, USA
| | - Joyce H. Lee
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Yifeng Hong
- Department of Electrical and Computer Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Joshua Jeong
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - James M. Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michelle D. Wang
- Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA
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12
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Shu J, Ding N, Liu J, Cui Y, Chen C. Transcription elongator SPT6L regulates the occupancies of the SWI2/SNF2 chromatin remodelers SYD/BRM and nucleosomes at transcription start sites in Arabidopsis. Nucleic Acids Res 2022; 50:12754-12767. [PMID: 36453990 PMCID: PMC9825159 DOI: 10.1093/nar/gkac1126] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 10/10/2022] [Accepted: 11/08/2022] [Indexed: 12/03/2022] Open
Abstract
Chromatin remodelers have been thought to be crucial in creating an accessible chromatin environment before transcription activation. However, it is still unclear how chromatin remodelers recognize and bind to the active regions. In this study, we found that chromatin remodelers SPLAYED (SYD) and BRAHMA (BRM) interact and co-occupy with Suppressor of Ty6-like (SPT6L), a core subunit of the transcription machinery, at thousands of the transcription start sites (TSS). The association of SYD and BRM to chromatin is dramatically reduced in spt6l and can be restored mainly by SPT6LΔtSH2, which binds to TSS in a RNA polymerase II (Pol II)-independent manner. Furthermore, SPT6L and SYD/BRM are involved in regulating the nucleosome and Pol II occupancy around TSS. The presence of SPT6L is sufficient to restore the association of the chromatin remodeler SYD to chromatin and maintain normal nucleosome occupancy. Our findings suggest that the two chromatin remodelers can form protein complexes with the core subunit of the transcription machinery and regulate nucleosome occupancy in the early transcription stage.
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Affiliation(s)
- Jie Shu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong 510650, China
| | - Ning Ding
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong 510650, China,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Liu
- Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong 510640, China
| | - Yuhai Cui
- Agriculture and Agri-Food Canada, London Research and Development Centre, London, Ontario N5V 4T3, Canada,Department of Biology, Western University, London, Ontario N6A 5B7, Canada
| | - Chen Chen
- To whom correspondence should be addressed. Tel: +86 20 37252711;
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13
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Oberhofer A, Bronkhorst AJ, Uhlig C, Ungerer V, Holdenrieder S. Tracing the Origin of Cell-Free DNA Molecules through Tissue-Specific Epigenetic Signatures. Diagnostics (Basel) 2022; 12:diagnostics12081834. [PMID: 36010184 PMCID: PMC9406971 DOI: 10.3390/diagnostics12081834] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/15/2022] [Accepted: 07/25/2022] [Indexed: 12/11/2022] Open
Abstract
All cell and tissue types constantly release DNA fragments into human body fluids by various mechanisms including programmed cell death, accidental cell degradation and active extrusion. Particularly, cell-free DNA (cfDNA) in plasma or serum has been utilized for minimally invasive molecular diagnostics. Disease onset or pathological conditions that lead to increased cell death alter the contribution of different tissues to the total pool of cfDNA. Because cfDNA molecules retain cell-type specific epigenetic features, it is possible to infer tissue-of-origin from epigenetic characteristics. Recent research efforts demonstrated that analysis of, e.g., methylation patterns, nucleosome occupancy, and fragmentomics determined the cell- or tissue-of-origin of individual cfDNA molecules. This novel tissue-of origin-analysis enables to estimate the contributions of different tissues to the total cfDNA pool in body fluids and find tissues with increased cell death (pathologic condition), expanding the portfolio of liquid biopsies towards a wide range of pathologies and early diagnosis. In this review, we summarize the currently available tissue-of-origin approaches and point out the next steps towards clinical implementation.
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14
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Isbel L, Grand RS, Schübeler D. Generating specificity in genome regulation through transcription factor sensitivity to chromatin. Nat Rev Genet 2022; 23:728-740. [PMID: 35831531 DOI: 10.1038/s41576-022-00512-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2022] [Indexed: 12/11/2022]
Abstract
Cell type-specific gene expression relies on transcription factors (TFs) binding DNA sequence motifs embedded in chromatin. Understanding how motifs are accessed in chromatin is crucial to comprehend differential transcriptional responses and the phenotypic impact of sequence variation. Chromatin obstacles to TF binding range from DNA methylation to restriction of DNA access by nucleosomes depending on their position, composition and modification. In vivo and in vitro approaches now enable the study of TF binding in chromatin at unprecedented resolution. Emerging insights suggest that TFs vary in their ability to navigate chromatin states. However, it remains challenging to link binding and transcriptional outcomes to molecular characteristics of TFs or the local chromatin substrate. Here, we discuss our current understanding of how TFs access DNA in chromatin and novel techniques and directions towards a better understanding of this critical step in genome regulation.
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Affiliation(s)
- Luke Isbel
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Ralph S Grand
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,Zentrum für Molekulare Biologie der Universität Heidelberg, Heidelberg, Germany
| | - Dirk Schübeler
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland. .,Faculty of Sciences, University of Basel, Basel, Switzerland.
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15
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Johnson SL, Narlikar GJ. ATP hydrolysis coordinates the activities of two motors in a dimeric chromatin remodeling enzyme. J Mol Biol 2022; 434:167653. [PMID: 35659534 DOI: 10.1016/j.jmb.2022.167653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 05/12/2022] [Accepted: 05/23/2022] [Indexed: 11/17/2022]
Abstract
ATP-dependent chromatin remodelers are essential enzymes that restructure eukaryotic genomes to enable all DNA-based processes. The diversity and complexity of these processes are matched by the complexity of the enzymes that carry them out, making remodelers a challenging class of molecular motors to study by conventional methods. Here we use a single molecule biophysical assay to overcome some of these challenges, enabling a detailed mechanistic dissection of a paradigmatic remodeler reaction, that of sliding a nucleosome towards the longer DNA linker. We focus on how two motors of a dimeric remodeler coordinate to accomplish such directional sliding. We find that ATP hydrolysis by both motors promotes coordination, suggesting a role for ATP in resolving the competition for directional commitment. Furthermore, we show an artificially constitutive dimer is no more or less coordinated, but is more processive, suggesting a cell could modulate a remodeler's oligomeric state to modulate local chromatin dynamics.
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Affiliation(s)
- Stephanie L Johnson
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA. https://twitter.com/StephL_Johnson
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
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16
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Karl LA, Peritore M, Galanti L, Pfander B. DNA Double Strand Break Repair and Its Control by Nucleosome Remodeling. Front Genet 2022; 12:821543. [PMID: 35096025 PMCID: PMC8790285 DOI: 10.3389/fgene.2021.821543] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 12/23/2021] [Indexed: 12/12/2022] Open
Abstract
DNA double strand breaks (DSBs) are repaired in eukaryotes by one of several cellular mechanisms. The decision-making process controlling DSB repair takes place at the step of DNA end resection, the nucleolytic processing of DNA ends, which generates single-stranded DNA overhangs. Dependent on the length of the overhang, a corresponding DSB repair mechanism is engaged. Interestingly, nucleosomes-the fundamental unit of chromatin-influence the activity of resection nucleases and nucleosome remodelers have emerged as key regulators of DSB repair. Nucleosome remodelers share a common enzymatic mechanism, but for global genome organization specific remodelers have been shown to exert distinct activities. Specifically, different remodelers have been found to slide and evict, position or edit nucleosomes. It is an open question whether the same remodelers exert the same function also in the context of DSBs. Here, we will review recent advances in our understanding of nucleosome remodelers at DSBs: to what extent nucleosome sliding, eviction, positioning and editing can be observed at DSBs and how these activities affect the DSB repair decision.
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Affiliation(s)
- Leonhard Andreas Karl
- Resarch Group DNA Replication and Genome Integrity, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Martina Peritore
- Resarch Group DNA Replication and Genome Integrity, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Lorenzo Galanti
- Resarch Group DNA Replication and Genome Integrity, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Boris Pfander
- Resarch Group DNA Replication and Genome Integrity, Max Planck Institute of Biochemistry, Martinsried, Germany
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17
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Gao X, Inman JT, Wang MD. Angular Optical Trapping to Directly Measure DNA Torsional Mechanics. Methods Mol Biol 2022; 2478:37-73. [PMID: 36063318 DOI: 10.1007/978-1-0716-2229-2_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] [Indexed: 04/14/2023]
Abstract
Angular optical trapping (AOT) is a powerful technique that permits direct angular manipulation of a trapped particle with simultaneous measurement of torque and rotation, while also retaining the capabilities of position and force detection. This technique provides unique approaches to investigate the torsional properties of nucleic acids and DNA-protein complexes, as well as impacts of torsional stress on fundamental biological processes, such as transcription and replication. Here we describe the principle, construction, and calibration of the AOT in detail and provide a guide to the performance of single-molecule torque measurements on DNA molecules. We include the constant-force method and, notably, a new constant-extension method that enables measurement of the twist persistence length of both extended DNA, under an extremely low force, and plectonemic DNA. This chapter can assist in the implementation and application of this technique for general researchers in the single-molecule field.
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Affiliation(s)
- Xiang Gao
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY, USA
- Laboratory of Atomic and Solid State Physics (LASSP), Department of Physics, Cornell University, Ithaca, NY, USA
| | - James T Inman
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY, USA
- Laboratory of Atomic and Solid State Physics (LASSP), Department of Physics, Cornell University, Ithaca, NY, USA
| | - Michelle D Wang
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY, USA.
- Laboratory of Atomic and Solid State Physics (LASSP), Department of Physics, Cornell University, Ithaca, NY, USA.
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18
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Reb1, Cbf1, and Pho4 bias histone sliding and deposition away from their binding sites. Mol Cell Biol 2021; 42:e0047221. [PMID: 34898278 DOI: 10.1128/mcb.00472-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In transcriptionally active genes, nucleosome positions in promoters are regulated by nucleosome displacing factors (NDFs) and chromatin remodeling enzymes. Depletion of NDFs or the RSC chromatin remodeler shrinks or abolishes the nucleosome depleted regions (NDRs) in promoters, which can suppress gene activation and result in cryptic transcription. Despite their vital cellular functions, how the action of chromatin remodelers may be directly affected by site-specific binding factors like NDFs is poorly understood. Here we demonstrate that two NDFs, Reb1 and Cbf1, can direct both Chd1 and RSC chromatin remodeling enzymes in vitro, stimulating repositioning of the histone core away from their binding sites. Interestingly, although the Pho4 transcription factor had a much weaker effect on nucleosome positioning, both NDFs and Pho4 were able to similarly redirect positioning of hexasomes. In chaperone-mediated nucleosome assembly assays, Reb1 but not Pho4 showed an ability to block deposition of the histone H3/H4 tetramer, but Reb1 did not block addition of the H2A/H2B dimer to hexasomes. Our in vitro results show that NDFs bias the action of remodelers to increase the length of the free DNA in the vicinity of their binding sites. These results suggest that NDFs could directly affect NDR architecture through chromatin remodelers.
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19
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Chatterjee D, Wittmeyer K, Lee TF, Cui J, Yennawar NH, Yennawar HP, Meyers BC, Chopra S. Maize unstable factor for orange1 is essential for endosperm development and carbohydrate accumulation. PLANT PHYSIOLOGY 2021; 186:1932-1950. [PMID: 33905500 PMCID: PMC8331166 DOI: 10.1093/plphys/kiab183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/07/2021] [Indexed: 06/12/2023]
Abstract
Maize (Zea mays L.) Ufo1-1 is a spontaneous dominant mutation of the unstable factor for orange1 (ufo1). We recently cloned ufo1, which is a Poaceae-specific gene highly expressed during seed development in maize. Here, we have characterized Ufo1-1 and a loss-of-function Ds insertion allele (ufo1-Dsg) to decipher the role of ufo1 in maize. We found that both ufo1 mutant alleles impact sugars and hormones, and have defects in the basal endosperm transfer layer (BETL) and adjacent cell types. The Ufo1-1 BETL had reduced cell elongation and cell wall ingrowth, resulting in cuboidal shaped transfer cells. In contrast, the ufo1-Dsg BETL cells showed a reduced overall size with abnormal wall ingrowth. Expression analysis identified the impact of ufo1 on several genes essential for BETL development. The overexpression of Ufo1-1 in various tissues leads to ectopic phenotypes, including abnormal cell organization and stomata subsidiary cell defects. Interestingly, pericarp and leaf transcriptomes also showed that as compared with wild type, Ufo1-1 had ectopic expression of endosperm development-specific genes. This study shows that Ufo1-1 impacts the expression patterns of a wide range of genes involved in various developmental processes.
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Affiliation(s)
- Debamalya Chatterjee
- Department of Plant Science, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Kameron Wittmeyer
- Department of Plant Science, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Intercollege Graduate Degree Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Tzuu-fen Lee
- The Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA
| | - Jin Cui
- Department of Plant Science, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Intercollege Graduate Degree Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Neela H Yennawar
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Hemant P Yennawar
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Blake C Meyers
- The Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA
- Division of Plant Sciences, University of Missouri, Columbia, Missouri 65201, USA
| | - Surinder Chopra
- Department of Plant Science, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Intercollege Graduate Degree Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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20
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Gamarra N, Narlikar GJ. Collaboration through chromatin: motors of transcription and chromatin structure. J Mol Biol 2021; 433:166876. [PMID: 33556407 PMCID: PMC8989640 DOI: 10.1016/j.jmb.2021.166876] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 01/09/2023]
Abstract
Packaging of the eukaryotic genome into chromatin places fundamental physical constraints on transcription. Clarifying how transcription operates within these constraints is essential to understand how eukaryotic gene expression programs are established and maintained. Here we review what is known about the mechanisms of transcription on chromatin templates. Current models indicate that transcription through chromatin is accomplished by the combination of an inherent nucleosome disrupting activity of RNA polymerase and the action of ATP-dependent chromatin remodeling motors. Collaboration between these two types of molecular motors is proposed to occur at all stages of transcription through diverse mechanisms. Further investigation of how these two motors combine their basic activities is essential to clarify the interdependent relationship between genome structure and transcription.
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Affiliation(s)
- Nathan Gamarra
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States; TETRAD Graduate Program, University of California, San Francisco, San Francisco, United States
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States.
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21
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Jovanovic VM, Sarfert M, Reyna-Blanco CS, Indrischek H, Valdivia DI, Shelest E, Nowick K. Positive Selection in Gene Regulatory Factors Suggests Adaptive Pleiotropic Changes During Human Evolution. Front Genet 2021; 12:662239. [PMID: 34079582 PMCID: PMC8166252 DOI: 10.3389/fgene.2021.662239] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/19/2021] [Indexed: 01/09/2023] Open
Abstract
Gene regulatory factors (GRFs), such as transcription factors, co-factors and histone-modifying enzymes, play many important roles in modifying gene expression in biological processes. They have also been proposed to underlie speciation and adaptation. To investigate potential contributions of GRFs to primate evolution, we analyzed GRF genes in 27 publicly available primate genomes. Genes coding for zinc finger (ZNF) proteins, especially ZNFs with a Krüppel-associated box (KRAB) domain were the most abundant TFs in all genomes. Gene numbers per TF family differed between all species. To detect signs of positive selection in GRF genes we investigated more than 3,000 human GRFs with their more than 70,000 orthologs in 26 non-human primates. We implemented two independent tests for positive selection, the branch-site-model of the PAML suite and aBSREL of the HyPhy suite, focusing on the human and great ape branch. Our workflow included rigorous procedures to reduce the number of false positives: excluding distantly similar orthologs, manual corrections of alignments, and considering only genes and sites detected by both tests for positive selection. Furthermore, we verified the candidate sites for selection by investigating their variation within human and non-human great ape population data. In order to approximately assign a date to positively selected sites in the human lineage, we analyzed archaic human genomes. Our work revealed with high confidence five GRFs that have been positively selected on the human lineage and one GRF that has been positively selected on the great ape lineage. These GRFs are scattered on different chromosomes and have been previously linked to diverse functions. For some of them a role in speciation and/or adaptation can be proposed based on the expression pattern or association with human diseases, but it seems that they all contributed independently to human evolution. Four of the positively selected GRFs are KRAB-ZNF proteins, that induce changes in target genes co-expression and/or through arms race with transposable elements. Since each positively selected GRF contains several sites with evidence for positive selection, we suggest that these GRFs participated pleiotropically to phenotypic adaptations in humans.
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Affiliation(s)
- Vladimir M Jovanovic
- Human Biology and Primate Evolution, Freie Universität Berlin, Berlin, Germany.,Bioinformatics Solution Center, Freie Universität Berlin, Berlin, Germany
| | - Melanie Sarfert
- Human Biology and Primate Evolution, Freie Universität Berlin, Berlin, Germany
| | - Carlos S Reyna-Blanco
- Department of Biology, University of Fribourg, Fribourg, Switzerland.,Swiss Institute of Bioinformatics, Fribourg, Switzerland
| | - Henrike Indrischek
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Systems Biology Dresden, Dresden, Germany
| | - Dulce I Valdivia
- Evolutionary Genomics Laboratory and Genome Topology and Regulation Laboratory, Genetic Engineering Department, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-Irapuato), Irapuato, Mexico
| | - Ekaterina Shelest
- Centre for Enzyme Innovation, University of Portsmouth, Portsmouth, United Kingdom
| | - Katja Nowick
- Human Biology and Primate Evolution, Freie Universität Berlin, Berlin, Germany
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22
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Liscovitch-Brauer N, Montalbano A, Deng J, Méndez-Mancilla A, Wessels HH, Moss NG, Kung CY, Sookdeo A, Guo X, Geller E, Jaini S, Smibert P, Sanjana NE. Profiling the genetic determinants of chromatin accessibility with scalable single-cell CRISPR screens. Nat Biotechnol 2021; 39:1270-1277. [PMID: 33927415 DOI: 10.1038/s41587-021-00902-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 03/13/2021] [Accepted: 03/17/2021] [Indexed: 12/17/2022]
Abstract
CRISPR screens have been used to connect genetic perturbations with changes in gene expression and phenotypes. Here we describe a CRISPR-based, single-cell combinatorial indexing assay for transposase-accessible chromatin (CRISPR-sciATAC) to link genetic perturbations to genome-wide chromatin accessibility in a large number of cells. In human myelogenous leukemia cells, we apply CRISPR-sciATAC to target 105 chromatin-related genes, generating chromatin accessibility data for ~30,000 single cells. We correlate the loss of specific chromatin remodelers with changes in accessibility globally and at the binding sites of individual transcription factors (TFs). For example, we show that loss of the H3K27 methyltransferase EZH2 increases accessibility at heterochromatic regions involved in embryonic development and triggers expression of genes in the HOXA and HOXD clusters. At a subset of regulatory sites, we also analyze changes in nucleosome spacing following the loss of chromatin remodelers. CRISPR-sciATAC is a high-throughput, single-cell method for studying the effect of genetic perturbations on chromatin in normal and disease states.
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Affiliation(s)
- Noa Liscovitch-Brauer
- New York Genome Center, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Antonino Montalbano
- New York Genome Center, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Jiale Deng
- New York Genome Center, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Alejandro Méndez-Mancilla
- New York Genome Center, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Hans-Hermann Wessels
- New York Genome Center, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Nicholas G Moss
- New York Genome Center, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Chia-Yu Kung
- New York Genome Center, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Akash Sookdeo
- New York Genome Center, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Xinyi Guo
- New York Genome Center, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Evan Geller
- New York Genome Center, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Suma Jaini
- New York Genome Center, New York, NY, USA.,Technology Innovation Lab, New York Genome Center, New York, NY, USA
| | - Peter Smibert
- New York Genome Center, New York, NY, USA.,Technology Innovation Lab, New York Genome Center, New York, NY, USA
| | - Neville E Sanjana
- New York Genome Center, New York, NY, USA. .,Department of Biology, New York University, New York, NY, USA.
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23
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Carzaniga T, Zanchetta G, Frezza E, Casiraghi L, Vanjur L, Nava G, Tagliabue G, Dieci G, Buscaglia M, Bellini T. A Bit Stickier, a Bit Slower, a Lot Stiffer: Specific vs. Nonspecific Binding of Gal4 to DNA. Int J Mol Sci 2021; 22:ijms22083813. [PMID: 33916983 PMCID: PMC8067546 DOI: 10.3390/ijms22083813] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/26/2021] [Accepted: 04/02/2021] [Indexed: 12/15/2022] Open
Abstract
Transcription factors regulate gene activity by binding specific regions of genomic DNA thanks to a subtle interplay of specific and nonspecific interactions that is challenging to quantify. Here, we exploit Reflective Phantom Interface (RPI), a label-free biosensor based on optical reflectivity, to investigate the binding of the N-terminal domain of Gal4, a well-known gene regulator, to double-stranded DNA fragments containing or not its consensus sequence. The analysis of RPI-binding curves provides interaction strength and kinetics and their dependence on temperature and ionic strength. We found that the binding of Gal4 to its cognate site is stronger, as expected, but also markedly slower. We performed a combined analysis of specific and nonspecific binding—equilibrium and kinetics—by means of a simple model based on nested potential wells and found that the free energy gap between specific and nonspecific binding is of the order of one kcal/mol only. We investigated the origin of such a small value by performing all-atom molecular dynamics simulations of Gal4–DNA interactions. We found a strong enthalpy–entropy compensation, by which the binding of Gal4 to its cognate sequence entails a DNA bending and a striking conformational freezing, which could be instrumental in the biological function of Gal4.
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Affiliation(s)
- Thomas Carzaniga
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano, 20054 Segrate (MI), Italy; (T.C.); (L.C.); (L.V.); (G.N.)
| | - Giuliano Zanchetta
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano, 20054 Segrate (MI), Italy; (T.C.); (L.C.); (L.V.); (G.N.)
- Correspondence: (G.Z.); (M.B.); (T.B.)
| | - Elisa Frezza
- CiTCoM, CNRS, Université de Paris, F-75006 Paris, France;
| | - Luca Casiraghi
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano, 20054 Segrate (MI), Italy; (T.C.); (L.C.); (L.V.); (G.N.)
| | - Luka Vanjur
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano, 20054 Segrate (MI), Italy; (T.C.); (L.C.); (L.V.); (G.N.)
| | - Giovanni Nava
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano, 20054 Segrate (MI), Italy; (T.C.); (L.C.); (L.V.); (G.N.)
| | | | - Giorgio Dieci
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, 43124 Parma, Italy;
| | - Marco Buscaglia
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano, 20054 Segrate (MI), Italy; (T.C.); (L.C.); (L.V.); (G.N.)
- Correspondence: (G.Z.); (M.B.); (T.B.)
| | - Tommaso Bellini
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano, 20054 Segrate (MI), Italy; (T.C.); (L.C.); (L.V.); (G.N.)
- Correspondence: (G.Z.); (M.B.); (T.B.)
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24
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Donovan DA, Crandall JG, Truong VN, Vaaler AL, Bailey TB, Dinwiddie D, Banks OGB, McKnight LE, McKnight JN. Basis of specificity for a conserved and promiscuous chromatin remodeling protein. eLife 2021; 10:e64061. [PMID: 33576335 PMCID: PMC7968928 DOI: 10.7554/elife.64061] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 02/11/2021] [Indexed: 12/11/2022] Open
Abstract
Eukaryotic genomes are organized dynamically through the repositioning of nucleosomes. Isw2 is an enzyme that has been previously defined as a genome-wide, nonspecific nucleosome spacing factor. Here, we show that Isw2 instead acts as an obligately targeted nucleosome remodeler in vivo through physical interactions with sequence-specific factors. We demonstrate that Isw2-recruiting factors use small and previously uncharacterized epitopes, which direct Isw2 activity through highly conserved acidic residues in the Isw2 accessory protein Itc1. This interaction orients Isw2 on target nucleosomes, allowing for precise nucleosome positioning at targeted loci. Finally, we show that these critical acidic residues have been lost in the Drosophila lineage, potentially explaining the inconsistently characterized function of Isw2-like proteins. Altogether, these data suggest an 'interacting barrier model,' where Isw2 interacts with a sequence-specific factor to accurately and reproducibly position a single, targeted nucleosome to define the precise border of phased chromatin arrays.
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Affiliation(s)
- Drake A Donovan
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | | | - Vi N Truong
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Abigail L Vaaler
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Thomas B Bailey
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Devin Dinwiddie
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Orion GB Banks
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Laura E McKnight
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Jeffrey N McKnight
- Institute of Molecular Biology, University of OregonEugeneUnited States
- Phil and Penny Knight Campus for Accelerating Scientific Impact, University of OregonEugeneUnited States
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25
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Mazina MY, Vorobyeva NE. Chromatin Modifiers in Transcriptional Regulation: New Findings and Prospects. Acta Naturae 2021; 13:16-30. [PMID: 33959384 PMCID: PMC8084290 DOI: 10.32607/actanaturae.11101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 12/17/2020] [Indexed: 02/04/2023] Open
Abstract
Histone-modifying and remodeling complexes are considered the main coregulators that affect transcription by changing the chromatin structure. Coordinated action by these complexes is essential for the transcriptional activation of any eukaryotic gene. In this review, we discuss current trends in the study of histone modifiers and chromatin remodelers, including the functional impact of transcriptional proteins/ complexes i.e., "pioneers"; remodeling and modification of non-histone proteins by transcriptional complexes; the supplementary functions of the non-catalytic subunits of remodelers, and the participation of histone modifiers in the "pause" of RNA polymerase II. The review also includes a scheme illustrating the mechanisms of recruitment of the main classes of remodelers and chromatin modifiers to various sites in the genome and their functional activities.
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Affiliation(s)
- M. Yu. Mazina
- Institute of Gene Biology RAS, Group of transcriptional complexes dynamics, Moscow, 119334 Russia
| | - N. E. Vorobyeva
- Institute of Gene Biology RAS, Group of transcriptional complexes dynamics, Moscow, 119334 Russia
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26
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Price RM, Budzyński MA, Kundra S, Teves SS. Advances in visualizing transcription factor - DNA interactions. Genome 2020; 64:449-466. [PMID: 33113335 DOI: 10.1139/gen-2020-0086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
At the heart of the transcription process is the specific interaction between transcription factors (TFs) and their target DNA sequences. Decades of molecular biology research have led to unprecedented insights into how TFs access the genome to regulate transcription. In the last 20 years, advances in microscopy have enabled scientists to add imaging as a powerful tool in probing two specific aspects of TF-DNA interactions: structure and dynamics. In this review, we examine how applications of diverse imaging technologies can provide structural and dynamic information that complements insights gained from molecular biology assays. As a case study, we discuss how applications of advanced imaging techniques have reshaped our understanding of TF behavior across the cell cycle, leading to a rethinking in the field of mitotic bookmarking.
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Affiliation(s)
- Rachel M Price
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.,Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Marek A Budzyński
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.,Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Shivani Kundra
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.,Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Sheila S Teves
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.,Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
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27
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Le TT, Gao X, Park SH, Lee J, Inman JT, Lee JH, Killian JL, Badman RP, Berger JM, Wang MD. Synergistic Coordination of Chromatin Torsional Mechanics and Topoisomerase Activity. Cell 2020; 179:619-631.e15. [PMID: 31626768 PMCID: PMC6899335 DOI: 10.1016/j.cell.2019.09.034] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 06/16/2019] [Accepted: 09/24/2019] [Indexed: 12/23/2022]
Abstract
DNA replication in eukaryotes generates DNA supercoiling, which may intertwine (braid) daughter chromatin fibers to form precatenanes, posing topological challenges during chromosome segregation. The mechanisms that limit precatenane formation remain unclear. By making direct torque measurements, we demonstrate that the intrinsic mechanical properties of chromatin play a fundamental role in dictating precatenane formation and regulating chromatin topology. Whereas a single chromatin fiber is torsionally soft, a braided fiber is torsionally stiff, indicating that supercoiling on chromatin substrates is preferentially directed in front of the fork during replication. We further show that topoisomerase II relaxation displays a strong preference for a single chromatin fiber over a braided fiber. These results suggest a synergistic coordination-the mechanical properties of chromatin inherently suppress precatenane formation during replication elongation by driving DNA supercoiling ahead of the fork, where supercoiling is more efficiently removed by topoisomerase II. VIDEO ABSTRACT.
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Affiliation(s)
- Tung T Le
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA; Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - Xiang Gao
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA; Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - Seong Ha Park
- Biophysics Program, Cornell University, Ithaca, NY 14853, USA
| | - Jaeyoon Lee
- Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - James T Inman
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA; Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - Joyce H Lee
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jessica L Killian
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA; Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - Ryan P Badman
- Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - James M Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michelle D Wang
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA; Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA.
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28
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Schiessel H, Blossey R. Pioneer transcription factors in chromatin remodeling: The kinetic proofreading view. Phys Rev E 2020; 101:040401. [PMID: 32422793 DOI: 10.1103/physreve.101.040401] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 03/23/2020] [Indexed: 06/11/2023]
Abstract
Pioneer transcription factors are a recently defined class of transcription factors which can bind directly to nucleosomal DNA; they play a key role in gene activation in certain pathways. Here we quantify their role in the initiation of nucleosome displacement within the kinetic proofreading scenario of chromatin remodeling. The model allows one to perform remodeling efficiency comparisons for scenarios involving different types of transcription factors and remodelers as a function of their binding and unbinding rates and concentrations. Our results demonstrate a way to fine-tune the specificity of processes that modify the chromatin structure in transcriptional initiation.
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Affiliation(s)
- Helmut Schiessel
- Institute Lorentz for Theoretical Physics, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, the Netherlands
| | - Ralf Blossey
- University of Lille, Unité de Glycobiologie Structurale et Fonctionnelle, CNRS UMR8576, 59000 Lille, France
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29
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Panchy NL, Lloyd JP, Shiu SH. Improved recovery of cell-cycle gene expression in Saccharomyces cerevisiae from regulatory interactions in multiple omics data. BMC Genomics 2020; 21:159. [PMID: 32054475 PMCID: PMC7020519 DOI: 10.1186/s12864-020-6554-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 02/04/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Gene expression is regulated by DNA-binding transcription factors (TFs). Together with their target genes, these factors and their interactions collectively form a gene regulatory network (GRN), which is responsible for producing patterns of transcription, including cyclical processes such as genome replication and cell division. However, identifying how this network regulates the timing of these patterns, including important interactions and regulatory motifs, remains a challenging task. RESULTS We employed four in vivo and in vitro regulatory data sets to investigate the regulatory basis of expression timing and phase-specific patterns cell-cycle expression in Saccharomyces cerevisiae. Specifically, we considered interactions based on direct binding between TF and target gene, indirect effects of TF deletion on gene expression, and computational inference. We found that the source of regulatory information significantly impacts the accuracy and completeness of recovering known cell-cycle expressed genes. The best approach involved combining TF-target and TF-TF interactions features from multiple datasets in a single model. In addition, TFs important to multiple phases of cell-cycle expression also have the greatest impact on individual phases. Important TFs regulating a cell-cycle phase also tend to form modules in the GRN, including two sub-modules composed entirely of unannotated cell-cycle regulators (STE12-TEC1 and RAP1-HAP1-MSN4). CONCLUSION Our findings illustrate the importance of integrating both multiple omics data and regulatory motifs in order to understand the significance regulatory interactions involved in timing gene expression. This integrated approached allowed us to recover both known cell-cycles interactions and the overall pattern of phase-specific expression across the cell-cycle better than any single data set. Likewise, by looking at regulatory motifs in the form of TF-TF interactions, we identified sets of TFs whose co-regulation of target genes was important for cell-cycle expression, even when regulation by individual TFs was not. Overall, this demonstrates the power of integrating multiple data sets and models of interaction in order to understand the regulatory basis of established biological processes and their associated gene regulatory networks.
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Affiliation(s)
- Nicholas L Panchy
- Genetics Graduate Program, Michigan State University, East Lansing, MI, 48824, USA.,Present address: National Institute for Mathematical and Biological Synthesis, University of Tennessee, 1122 Volunteer Blvd., Suite 106, Knoxville, TN, 37996-3410, USA
| | - John P Lloyd
- Department of Human Genetics and Internal Medicine, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Shin-Han Shiu
- Genetics Graduate Program, Michigan State University, East Lansing, MI, 48824, USA. .,Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, MI, 48824, USA. .,Michigan State University, Plant Biology Laboratories, 612 Wilson Road, Room 166, East Lansing, MI, 48824-1312, USA.
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30
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Epigenome Regulation by Dynamic Nucleosome Unwrapping. Trends Biochem Sci 2020; 45:13-26. [PMID: 31630896 PMCID: PMC10168609 DOI: 10.1016/j.tibs.2019.09.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/09/2019] [Accepted: 09/13/2019] [Indexed: 12/12/2022]
Abstract
Gene regulation in eukaryotes requires the controlled access of sequence-specific transcription factors (TFs) to their sites in a chromatin landscape dominated by nucleosomes. Nucleosomes are refractory to TF binding, and often must be removed from regulatory regions. Recent genomic studies together with in vitro measurements suggest that the nucleosome barrier to TF binding is modulated by dynamic nucleosome unwrapping governed by ATP-dependent chromatin remodelers. Genome-wide occupancy and the regulation of subnucleosomal intermediates have gained recent attention with the application of high-resolution approaches for precision mapping of protein-DNA interactions. We summarize here recent findings on nucleosome substructures and TF binding dynamics, and highlight how unwrapped nucleosomal intermediates provide a novel signature of active chromatin.
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31
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Wu T, Kamikawa YF, Donohoe ME. Brd4's Bromodomains Mediate Histone H3 Acetylation and Chromatin Remodeling in Pluripotent Cells through P300 and Brg1. Cell Rep 2019; 25:1756-1771. [PMID: 30428346 DOI: 10.1016/j.celrep.2018.10.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/10/2016] [Accepted: 09/28/2018] [Indexed: 12/22/2022] Open
Abstract
The pluripotent state of embryonic stem cells (ESCs) is defined by its transcriptome and epigenome. The chromatin reader Brd4 determines ESC identity. Although Brd4 regulation in gene transcription has been well described, its contribution to the chromatin landscape is less known. Here, we show that Brd4's bromodomains partner with the histone acetyltransferase P300, increasing its enzymatic activities. Augmenting histone acetylation by Brd4-P300 interaction recruits the chromatin remodeler Brg1 altering chromatin structure. This pathway is important for maintaining the expression and chromatin patterns of pluripotency-associated genes, such as Oct4, Nanog, and the X chromosome regulatory long noncoding RNAs Tsix and Xite. Furthermore, we show that the Brd4-P300 interaction regulates the de novo formation of chromatin marks during ESC differentiation, as exemplified by controlling the master regulators of mesoderm formation. Collectively, we delineate the function of Brd4 in organizing the chromatin structure that contributes to gene transcriptional regulation and cell fate determination.
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Affiliation(s)
- Tao Wu
- Burke Medical Research Institute, White Plains, NY 10605, USA; Department of Neuroscience, Brain Mind Research Institute, Department of Cell & Development, Weill Cornell Medical College, New York, NY 10065, USA
| | - Yasunao F Kamikawa
- Burke Medical Research Institute, White Plains, NY 10605, USA; Department of Neuroscience, Brain Mind Research Institute, Department of Cell & Development, Weill Cornell Medical College, New York, NY 10065, USA
| | - Mary E Donohoe
- Burke Medical Research Institute, White Plains, NY 10605, USA; Department of Neuroscience, Brain Mind Research Institute, Department of Cell & Development, Weill Cornell Medical College, New York, NY 10065, USA.
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32
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Mohapatra S, Lin CT, Feng XA, Basu A, Ha T. Single-Molecule Analysis and Engineering of DNA Motors. Chem Rev 2019; 120:36-78. [DOI: 10.1021/acs.chemrev.9b00361] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
| | | | | | | | - Taekjip Ha
- Howard Hughes Medical Institute, Baltimore, Maryland 21205, United States
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33
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Wang AW, Wang YJ, Zahm AM, Morgan AR, Wangensteen KJ, Kaestner KH. The Dynamic Chromatin Architecture of the Regenerating Liver. Cell Mol Gastroenterol Hepatol 2019; 9:121-143. [PMID: 31629814 PMCID: PMC6909351 DOI: 10.1016/j.jcmgh.2019.09.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 09/19/2019] [Accepted: 09/23/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS The adult liver is the main detoxification organ and routinely is exposed to environmental insults but retains the ability to restore its mass and function upon tissue damage. However, extensive injury can lead to liver failure, and chronic injury causes fibrosis, cirrhosis, and hepatocellular carcinoma. Currently, the transcriptional regulation of organ repair in the adult liver is incompletely understood. METHODS We isolated nuclei from quiescent as well as repopulating hepatocytes in a mouse model of hereditary tyrosinemia, which recapitulates the injury and repopulation seen in toxic liver injury in human beings. We then performed the assay for transposase accessible chromatin with high-throughput sequencing specifically in repopulating hepatocytes to identify differentially accessible chromatin regions and nucleosome positioning. In addition, we used motif analysis to predict differential transcription factor occupancy and validated the in silico results with chromatin immunoprecipitation followed by sequencing for hepatocyte nuclear factor 4α (HNF4α) and CCCTC-binding factor (CTCF). RESULTS Chromatin accessibility in repopulating hepatocytes was increased in the regulatory regions of genes promoting proliferation and decreased in the regulatory regions of genes involved in metabolism. The epigenetic changes at promoters and liver enhancers correspond with the regulation of gene expression, with enhancers of many liver function genes showing a less accessible state during the regenerative process. Moreover, increased CTCF occupancy at promoters and decreased HNF4α binding at enhancers implicate these factors as key drivers of the transcriptomic changes in replicating hepatocytes that enable liver repopulation. CONCLUSIONS Our analysis of hepatocyte-specific epigenomic changes during liver repopulation identified CTCF and HNF4α as key regulators of hepatocyte proliferation and regulation of metabolic programs. Thus, liver repopulation in the setting of toxic injury makes use of both general transcription factors (CTCF) for promoter activation, and reduced binding by a hepatocyte-enriched factor (HNF4α) to temporarily limit enhancer activity. All sequencing data in this study were deposited to the Gene Expression Omnibus database and can be downloaded with accession number GSE109466.
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Affiliation(s)
- Amber W Wang
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Yue J Wang
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida
| | - Adam M Zahm
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ashleigh R Morgan
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kirk J Wangensteen
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Klaus H Kaestner
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania.
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34
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Owens N, Papadopoulou T, Festuccia N, Tachtsidi A, Gonzalez I, Dubois A, Vandormael-Pournin S, Nora EP, Bruneau BG, Cohen-Tannoudji M, Navarro P. CTCF confers local nucleosome resiliency after DNA replication and during mitosis. eLife 2019; 8:e47898. [PMID: 31599722 PMCID: PMC6844645 DOI: 10.7554/elife.47898] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 10/09/2019] [Indexed: 12/20/2022] Open
Abstract
The access of Transcription Factors (TFs) to their cognate DNA binding motifs requires a precise control over nucleosome positioning. This is especially important following DNA replication and during mitosis, both resulting in profound changes in nucleosome organization over TF binding regions. Using mouse Embryonic Stem (ES) cells, we show that the TF CTCF displaces nucleosomes from its binding site and locally organizes large and phased nucleosomal arrays, not only in interphase steady-state but also immediately after replication and during mitosis. Correlative analyses suggest this is associated with fast gene reactivation following replication and mitosis. While regions bound by other TFs (Oct4/Sox2), display major rearrangement, the post-replication and mitotic nucleosome positioning activity of CTCF is not unique: Esrrb binding regions are also characterized by persistent nucleosome positioning. Therefore, selected TFs such as CTCF and Esrrb act as resilient TFs governing the inheritance of nucleosome positioning at regulatory regions throughout the cell-cycle.
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Affiliation(s)
- Nick Owens
- Epigenomics, Proliferation, and the Identity of Cells, Department of Developmental and Stem Cell BiologyInstitut Pasteur, CNRS UMR3738ParisFrance
- Equipe Labellisée LIGUE Contre le CancerParisFrance
| | - Thaleia Papadopoulou
- Epigenomics, Proliferation, and the Identity of Cells, Department of Developmental and Stem Cell BiologyInstitut Pasteur, CNRS UMR3738ParisFrance
- Equipe Labellisée LIGUE Contre le CancerParisFrance
| | - Nicola Festuccia
- Epigenomics, Proliferation, and the Identity of Cells, Department of Developmental and Stem Cell BiologyInstitut Pasteur, CNRS UMR3738ParisFrance
- Equipe Labellisée LIGUE Contre le CancerParisFrance
| | - Alexandra Tachtsidi
- Epigenomics, Proliferation, and the Identity of Cells, Department of Developmental and Stem Cell BiologyInstitut Pasteur, CNRS UMR3738ParisFrance
- Equipe Labellisée LIGUE Contre le CancerParisFrance
- Sorbonne Université, Collège DoctoralParisFrance
| | - Inma Gonzalez
- Epigenomics, Proliferation, and the Identity of Cells, Department of Developmental and Stem Cell BiologyInstitut Pasteur, CNRS UMR3738ParisFrance
- Equipe Labellisée LIGUE Contre le CancerParisFrance
| | - Agnes Dubois
- Epigenomics, Proliferation, and the Identity of Cells, Department of Developmental and Stem Cell BiologyInstitut Pasteur, CNRS UMR3738ParisFrance
- Equipe Labellisée LIGUE Contre le CancerParisFrance
| | - Sandrine Vandormael-Pournin
- Epigenomics, Proliferation, and the Identity of Cells, Department of Developmental and Stem Cell BiologyInstitut Pasteur, CNRS UMR3738ParisFrance
- Early Mammalian Development and Stem Cell Biology, Department of Developmental and Stem Cell BiologyInstitut Pasteur, CNRS UMR 3738ParisFrance
| | - Elphège P Nora
- Gladstone InstitutesSan FranciscoUnited States
- Cardiovascular Research InstituteUniversity of California, San FranciscoSan FranciscoUnited States
| | - Benoit G Bruneau
- Gladstone InstitutesSan FranciscoUnited States
- Cardiovascular Research InstituteUniversity of California, San FranciscoSan FranciscoUnited States
- Department of PediatricsUniversity of California, San FranciscoSan FranciscoUnited States
| | - Michel Cohen-Tannoudji
- Epigenomics, Proliferation, and the Identity of Cells, Department of Developmental and Stem Cell BiologyInstitut Pasteur, CNRS UMR3738ParisFrance
- Early Mammalian Development and Stem Cell Biology, Department of Developmental and Stem Cell BiologyInstitut Pasteur, CNRS UMR 3738ParisFrance
| | - Pablo Navarro
- Epigenomics, Proliferation, and the Identity of Cells, Department of Developmental and Stem Cell BiologyInstitut Pasteur, CNRS UMR3738ParisFrance
- Equipe Labellisée LIGUE Contre le CancerParisFrance
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35
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Perdomo-Sabogal Á, Nowick K. Genetic Variation in Human Gene Regulatory Factors Uncovers Regulatory Roles in Local Adaptation and Disease. Genome Biol Evol 2019; 11:2178-2193. [PMID: 31228201 PMCID: PMC6685493 DOI: 10.1093/gbe/evz131] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2019] [Indexed: 01/13/2023] Open
Abstract
Differences in gene regulation have been suggested to play essential roles in the evolution of phenotypic changes. Although DNA changes in cis-regulatory elements affect only the regulation of its corresponding gene, variations in gene regulatory factors (trans) can have a broader effect, because the expression of many target genes might be affected. Aiming to better understand how natural selection may have shaped the diversity of gene regulatory factors in human, we assembled a catalog of all proteins involved in controlling gene expression. We found that at least five DNA-binding transcription factor classes are enriched among genes located in candidate regions for selection, suggesting that they might be relevant for understanding regulatory mechanisms involved in human local adaptation. The class of KRAB-ZNFs, zinc-finger (ZNF) genes with a Krüppel-associated box, stands out by first, having the most genes located on candidate regions for positive selection. Second, displaying most nonsynonymous single nucleotide polymorphisms (SNPs) with high genetic differentiation between populations within these regions. Third, having 27 KRAB-ZNF gene clusters with high extended haplotype homozygosity. Our further characterization of nonsynonymous SNPs in ZNF genes located within candidate regions for selection, suggests regulatory modifications that might influence the expression of target genes at population level. Our detailed investigation of three candidate regions revealed possible explanations for how SNPs may influence the prevalence of schizophrenia, eye development, and fertility in humans, among other phenotypes. The genetic variation we characterized here may be responsible for subtle to rough regulatory changes that could be important for understanding human adaptation.
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Affiliation(s)
- Álvaro Perdomo-Sabogal
- Human Biology Group, Department of Biology, Chemistry and Pharmacy, Institute for Zoology, Freie Universität Berlin, Germany
| | - Katja Nowick
- Human Biology Group, Department of Biology, Chemistry and Pharmacy, Institute for Zoology, Freie Universität Berlin, Germany
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36
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Rudnizky S, Khamis H, Malik O, Squires AH, Meller A, Melamed P, Kaplan A. Single-molecule DNA unzipping reveals asymmetric modulation of a transcription factor by its binding site sequence and context. Nucleic Acids Res 2019; 46:1513-1524. [PMID: 29253225 PMCID: PMC5815098 DOI: 10.1093/nar/gkx1252] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 12/11/2017] [Indexed: 12/31/2022] Open
Abstract
Most functional transcription factor (TF) binding sites deviate from their ‘consensus’ recognition motif, although their sites and flanking sequences are often conserved across species. Here, we used single-molecule DNA unzipping with optical tweezers to study how Egr-1, a TF harboring three zinc fingers (ZF1, ZF2 and ZF3), is modulated by the sequence and context of its functional sites in the Lhb gene promoter. We find that both the core 9 bp bound to Egr-1 in each of the sites, and the base pairs flanking them, modulate the affinity and structure of the protein–DNA complex. The effect of the flanking sequences is asymmetric, with a stronger effect for the sequence flanking ZF3. Characterization of the dissociation time of Egr-1 revealed that a local, mechanical perturbation of the interactions of ZF3 destabilizes the complex more effectively than a perturbation of the ZF1 interactions. Our results reveal a novel role for ZF3 in the interaction of Egr-1 with other proteins and the DNA, providing insight on the regulation of Lhb and other genes by Egr-1. Moreover, our findings reveal the potential of small changes in DNA sequence to alter transcriptional regulation, and may shed light on the organization of regulatory elements at promoters.
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Affiliation(s)
- Sergei Rudnizky
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Hadeel Khamis
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Faculty of Physics, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Omri Malik
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Allison H Squires
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Amit Meller
- Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.,Faculty of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Philippa Melamed
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Ariel Kaplan
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
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37
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Gutiérrez MP, MacAlpine HK, MacAlpine DM. Nascent chromatin occupancy profiling reveals locus- and factor-specific chromatin maturation dynamics behind the DNA replication fork. Genome Res 2019; 29:1123-1133. [PMID: 31217252 PMCID: PMC6633257 DOI: 10.1101/gr.243386.118] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 05/28/2019] [Indexed: 01/06/2023]
Abstract
Proper regulation and maintenance of the epigenome is necessary to preserve genome function. However, in every cell division, the epigenetic state is disassembled and then reassembled in the wake of the DNA replication fork. Chromatin restoration on nascent DNA is a complex and regulated process that includes nucleosome assembly and remodeling, deposition of histone variants, and the re-establishment of transcription factor binding. To study the genome-wide dynamics of chromatin restoration behind the DNA replication fork, we developed nascent chromatin occupancy profiles (NCOPs) to comprehensively profile nascent and mature chromatin at nucleotide resolution. Although nascent chromatin is inherently less organized than mature chromatin, we identified locus-specific differences in the kinetics of chromatin maturation that were predicted by the epigenetic landscape, including the histone variant H2AZ, which marked loci with rapid maturation kinetics. The chromatin maturation at origins of DNA replication was dependent on whether the origin underwent initiation or was passively replicated from distal-originating replication forks, suggesting distinct chromatin assembly mechanisms surrounding activated and disassembled prereplicative complexes. Finally, we identified sites that were only occupied transiently by DNA-binding factors following passage of the replication fork, which may provide a mechanism for perturbations of the DNA replication program to shape the regulatory landscape of the genome.
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Affiliation(s)
- Mónica P Gutiérrez
- University Program in Genetics and Genomics, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Heather K MacAlpine
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - David M MacAlpine
- University Program in Genetics and Genomics, Duke University Medical Center, Durham, North Carolina 27710, USA
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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38
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Soleimani VD, Nguyen D, Ramachandran P, Palidwor GA, Porter CJ, Yin H, Perkins TJ, Rudnicki MA. Cis-regulatory determinants of MyoD function. Nucleic Acids Res 2019; 46:7221-7235. [PMID: 30016497 PMCID: PMC6101602 DOI: 10.1093/nar/gky388] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 04/30/2018] [Indexed: 01/06/2023] Open
Abstract
Muscle-specific transcription factor MyoD orchestrates the myogenic gene expression program by binding to short DNA motifs called E-boxes within myogenic cis-regulatory elements (CREs). Genome-wide analyses of MyoD cistrome by chromatin immnunoprecipitation sequencing shows that MyoD-bound CREs contain multiple E-boxes of various sequences. However, how E-box numbers, sequences and their spatial arrangement within CREs collectively regulate the binding affinity and transcriptional activity of MyoD remain largely unknown. Here, by an integrative analysis of MyoD cistrome combined with genome-wide analysis of key regulatory histones and gene expression data we show that the affinity landscape of MyoD is driven by multiple E-boxes, and that the overall binding affinity—and associated nucleosome positioning and epigenetic features of the CREs—crucially depend on the variant sequences and positioning of the E-boxes within the CREs. By comparative genomic analysis of single nucleotide polymorphism (SNPs) across publicly available data from 17 strains of laboratory mice, we show that variant sequences within the MyoD-bound motifs, but not their genome-wide counterparts, are under selection. At last, we show that the quantitative regulatory effect of MyoD binding on the nearby genes can, in part, be predicted by the motif composition of the CREs to which it binds. Taken together, our data suggest that motif numbers, sequences and their spatial arrangement within the myogenic CREs are important determinants of the cis-regulatory code of myogenic CREs.
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Affiliation(s)
- Vahab D Soleimani
- Department of Human Genetics, McGill University, Montréal, QC H3A 1B1, Canada.,Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, QC H3T 1E2, Canada
| | - Duy Nguyen
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, QC H3T 1E2, Canada
| | - Parameswaran Ramachandran
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Gareth A Palidwor
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Christopher J Porter
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Hang Yin
- Center for Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Georgia, GA 30602, USA
| | - Theodore J Perkins
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Michael A Rudnicki
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
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39
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Levendosky RF, Bowman GD. Asymmetry between the two acidic patches dictates the direction of nucleosome sliding by the ISWI chromatin remodeler. eLife 2019; 8:45472. [PMID: 31094676 PMCID: PMC6546392 DOI: 10.7554/elife.45472] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 05/16/2019] [Indexed: 01/15/2023] Open
Abstract
The acidic patch is a functionally important epitope on each face of the nucleosome that affects chromatin remodeling. Although related by 2-fold symmetry of the nucleosome, each acidic patch is uniquely positioned relative to a bound remodeler. An open question is whether remodelers are distinctly responsive to each acidic patch. Previously we reported a method for homogeneously producing asymmetric nucleosomes with distinct H2A/H2B dimers (Levendosky et al., 2016). Here, we use this methodology to show that the Chd1 remodeler from Saccharomyces cerevisiae and ISWI remodelers from human and Drosophila have distinct spatial requirements for the acidic patch. Unlike Chd1, which is equally affected by entry- and exit-side mutations, ISWI remodelers strongly depend on the entry-side acidic patch. Remarkably, asymmetry in the two acidic patches stimulates ISWI to slide mononucleosomes off DNA ends, overriding the remodeler’s preference to shift the histone core toward longer flanking DNA.
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Affiliation(s)
- Robert F Levendosky
- TC Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, United States
| | - Gregory D Bowman
- TC Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, United States
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40
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Kulkarni V, Kulkarni P. Intrinsically disordered proteins and phenotypic switching: Implications in cancer. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 166:63-84. [PMID: 31521237 DOI: 10.1016/bs.pmbts.2019.03.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
It is now well established that intrinsically disordered proteins (IDPs) that constitute a large part of the proteome across the three kingdoms, play critical roles in several biological processes including phenotypic switching. However, dysregulated expression of IDPs that engage in promiscuous interactions can lead to pathological states. In this chapter, using cancer as a paradigm, we discuss how IDP conformational dynamics and the resultant conformational noise can modulate phenotypic switching. Thus, contrary to the prevailing wisdom that phenotypic switching is highly deterministic (has a genetic underpinning) in cancer, emerging evidence suggests that non-genetic mechanisms, at least in part due to the conformational noise, may also be a confounding factor in phenotypic switching.
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Affiliation(s)
- Vivek Kulkarni
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Prakash Kulkarni
- Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, CA, United States.
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41
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Navarrete-Modesto V, Orozco-Suárez S, Feria-Romero IA, Rocha L. The molecular hallmarks of epigenetic effects mediated by antiepileptic drugs. Epilepsy Res 2019; 149:53-65. [DOI: 10.1016/j.eplepsyres.2018.11.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 10/16/2018] [Accepted: 11/14/2018] [Indexed: 02/06/2023]
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42
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Killian JL, Inman JT, Wang MD. High-Performance Image-Based Measurements of Biological Forces and Interactions in a Dual Optical Trap. ACS NANO 2018; 12:11963-11974. [PMID: 30457331 PMCID: PMC6857636 DOI: 10.1021/acsnano.8b03679] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Optical traps enable the nanoscale manipulation of individual biomolecules while measuring molecular forces and lengths. This ability relies on the sensitive detection of optically trapped particles, typically accomplished using laser-based interferometric methods. Recently, image-based particle tracking techniques have garnered increased interest as a potential alternative to laser-based detection; however, successful integration of image-based methods into optical trapping instruments for biophysical applications and force measurements has remained elusive. Here, we develop a camera-based detection platform that enables accurate and precise measurements of biological forces and interactions in a dual optical trap. In demonstration, we stretch and unzip DNA molecules while measuring the relative distances of trapped particles from their trapping centers with sub-nanometer accuracy and precision. We then use the DNA unzipping technique to localize bound proteins with sub-base-pair precision, revealing how thermal DNA "breathing" fluctuations allow an unzipping fork to detect and respond to the presence of a protein bound downstream. This work advances the capabilities of image tracking in optical traps, providing a state-of-the-art detection method that is accessible, highly flexible, and broadly compatible with diverse experimental substrates and other nanometric techniques.
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Affiliation(s)
- Jessica L. Killian
- Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA
| | - James T. Inman
- Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA
| | - Michelle D. Wang
- Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA
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43
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Brahma S, Henikoff S. RSC-Associated Subnucleosomes Define MNase-Sensitive Promoters in Yeast. Mol Cell 2018; 73:238-249.e3. [PMID: 30554944 PMCID: PMC6475595 DOI: 10.1016/j.molcel.2018.10.046] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/04/2018] [Accepted: 10/30/2018] [Indexed: 02/07/2023]
Abstract
The classic view of nucleosome organization at active promoters is that two well-positioned nucleosomes flank a nucleosome-depleted region (NDR). However, this view has been recently disputed by contradictory reports as to whether wider (≳150 bp) NDRs instead contain unstable, micrococcal nuclease-sensitive ("fragile") nucleosomal particles. To determine the composition of fragile particles, we introduce CUT&RUN.ChIP, in which targeted nuclease cleavage and release is followed by chromatin immunoprecipitation. We find that fragile particles represent the occupancy of the RSC (remodeling the structure of chromatin) nucleosome remodeling complex and RSC-bound, partially unwrapped nucleosomal intermediates. We also find that general regulatory factors (GRFs) bind to partially unwrapped nucleosomes at these promoters. We propose that RSC binding and its action cause nucleosomes to unravel, facilitate subsequent binding of GRFs, and constitute a dynamic cycle of nucleosome deposition and clearance at the subset of wide Pol II promoter NDRs.
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Affiliation(s)
- Sandipan Brahma
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Steven Henikoff
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Howard Hughes Medical Institute, USA.
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44
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Mehta GD, Ball DA, Eriksson PR, Chereji RV, Clark DJ, McNally JG, Karpova TS. Single-Molecule Analysis Reveals Linked Cycles of RSC Chromatin Remodeling and Ace1p Transcription Factor Binding in Yeast. Mol Cell 2018; 72:875-887.e9. [PMID: 30318444 DOI: 10.1016/j.molcel.2018.09.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/08/2018] [Accepted: 09/07/2018] [Indexed: 12/12/2022]
Abstract
It is unknown how the dynamic binding of transcription factors (TFs) is molecularly linked to chromatin remodeling and transcription. Using single-molecule tracking (SMT), we show that the chromatin remodeler RSC speeds up the search process of the TF Ace1p for its response elements (REs) at the CUP1 promoter. We quantified smFISH mRNA data using a gene bursting model and demonstrated that RSC regulates transcription bursts of CUP1 only by modulating TF occupancy but does not affect initiation and elongation rates. We show by SMT that RSC binds to activated promoters transiently, and based on MNase-seq data, that RSC does not affect the nucleosomal occupancy at CUP1. Therefore, transient binding of Ace1p and rapid bursts of transcription at CUP1 may be dependent on short repetitive cycles of nucleosome mobilization. This type of regulation reduces the transcriptional noise and ensures a homogeneous response of the cell population to heavy metal stress.
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Affiliation(s)
- Gunjan D Mehta
- CCR/LRBGE Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David A Ball
- CCR/LRBGE Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter R Eriksson
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Razvan V Chereji
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - David J Clark
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - James G McNally
- Institute for Soft Matter and Functional Materials, Helmholtz Center Berlin, Berlin 12489, Germany
| | - Tatiana S Karpova
- CCR/LRBGE Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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45
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Le TT, Wang MD. Molecular Highways—Navigating Collisions of DNA Motor Proteins. J Mol Biol 2018; 430:4513-4524. [DOI: 10.1016/j.jmb.2018.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 07/31/2018] [Accepted: 08/03/2018] [Indexed: 01/09/2023]
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46
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The interaction landscape between transcription factors and the nucleosome. Nature 2018; 562:76-81. [PMID: 30250250 PMCID: PMC6173309 DOI: 10.1038/s41586-018-0549-5] [Citation(s) in RCA: 200] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 08/06/2018] [Indexed: 01/01/2023]
Abstract
Nucleosomes cover most of the genome and are thought to be displaced by transcription factors in regions that direct gene expression. However, the modes of interaction between transcription factors and nucleosomal DNA remain largely unknown. Here we systematically explore interactions between the nucleosome and 220 transcription factors representing diverse structural families. Consistent with earlier observations, we find that the majority of the studied transcription factors have less access to nucleosomal DNA than to free DNA. The motifs recovered from transcription factors bound to nucleosomal and free DNA are generally similar. However, steric hindrance and scaffolding by the nucleosome result in specific positioning and orientation of the motifs. Many transcription factors preferentially bind close to the end of nucleosomal DNA, or to periodic positions on the solvent-exposed side of the DNA. In addition, several transcription factors usually bind to nucleosomal DNA in a particular orientation. Some transcription factors specifically interact with DNA located at the dyad position at which only one DNA gyre is wound, whereas other transcription factors prefer sites spanning two DNA gyres and bind specifically to each of them. Our work reveals notable differences in the binding of transcription factors to free and nucleosomal DNA, and uncovers a diverse interaction landscape between transcription factors and the nucleosome.
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47
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Swinstead EE, Paakinaho V, Hager GL. Chromatin reprogramming in breast cancer. Endocr Relat Cancer 2018; 25:R385-R404. [PMID: 29692347 PMCID: PMC6029727 DOI: 10.1530/erc-18-0033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 04/24/2018] [Indexed: 02/06/2023]
Abstract
Reprogramming of the chromatin landscape is a critical component to the transcriptional response in breast cancer. Effects of sex hormones such as estrogens and progesterone have been well described to have a critical impact on breast cancer proliferation. However, the complex network of the chromatin landscape, enhancer regions and mode of function of steroid receptors (SRs) and other transcription factors (TFs), is an intricate web of signaling and functional processes that is still largely misunderstood at the mechanistic level. In this review, we describe what is currently known about the dynamic interplay between TFs with chromatin and the reprogramming of enhancer elements. Emphasis has been placed on characterizing the different modes of action of TFs in regulating enhancer activity, specifically, how different SRs target enhancer regions to reprogram chromatin in breast cancer cells. In addition, we discuss current techniques employed to study enhancer function at a genome-wide level. Further, we have noted recent advances in live cell imaging technology. These single-cell approaches enable the coupling of population-based assays with real-time studies to address many unsolved questions about SRs and chromatin dynamics in breast cancer.
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Affiliation(s)
- Erin E Swinstead
- Laboratory of Receptor Biology and Gene ExpressionNational Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Ville Paakinaho
- Laboratory of Receptor Biology and Gene ExpressionNational Cancer Institute, NIH, Bethesda, Maryland, USA
- Institute of BiomedicineUniversity of Eastern Finland, Kuopio, Finland
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene ExpressionNational Cancer Institute, NIH, Bethesda, Maryland, USA
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48
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Helicase promotes replication re-initiation from an RNA transcript. Nat Commun 2018; 9:2306. [PMID: 29899338 PMCID: PMC5997990 DOI: 10.1038/s41467-018-04702-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 04/30/2018] [Indexed: 11/12/2022] Open
Abstract
To ensure accurate DNA replication, a replisome must effectively overcome numerous obstacles on its DNA substrate. After encountering an obstacle, a progressing replisome often aborts DNA synthesis but continues to unwind. However, little is known about how DNA synthesis is resumed downstream of an obstacle. Here, we examine the consequences of a non-replicating replisome collision with a co-directional RNA polymerase (RNAP). Using single-molecule and ensemble methods, we find that T7 helicase interacts strongly with a non-replicating T7 DNA polymerase (DNAP) at a replication fork. As the helicase advances, the associated DNAP also moves forward. The presence of the DNAP increases both helicase’s processivity and unwinding rate. We show that such a DNAP, together with its helicase, is indeed able to actively disrupt a stalled transcription elongation complex, and then initiates replication using the RNA transcript as a primer. These observations exhibit T7 helicase’s novel role in replication re-initiation. During DNA replication, replicative helicases play an essential role for DNA unwinding to occur. Here the authors find that bacteriophage T7 helicase is also involved in replication re-initiation by interacting with a non-replicating DNAP and increasing unwinding rate.
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49
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Le TT, Yang Y, Tan C, Suhanovsky MM, Fulbright RM, Inman JT, Li M, Lee J, Perelman S, Roberts JW, Deaconescu AM, Wang MD. Mfd Dynamically Regulates Transcription via a Release and Catch-Up Mechanism. Cell 2017; 172:344-357.e15. [PMID: 29224782 DOI: 10.1016/j.cell.2017.11.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 09/21/2017] [Accepted: 11/09/2017] [Indexed: 11/25/2022]
Abstract
The bacterial Mfd ATPase is increasingly recognized as a general transcription factor that participates in the resolution of transcription conflicts with other processes/roadblocks. This function stems from Mfd's ability to preferentially act on stalled RNA polymerases (RNAPs). However, the mechanism underlying this preference and the subsequent coordination between Mfd and RNAP have remained elusive. Here, using a novel real-time translocase assay, we unexpectedly discovered that Mfd translocates autonomously on DNA. The speed and processivity of Mfd dictate a "release and catch-up" mechanism to efficiently patrol DNA for frequently stalled RNAPs. Furthermore, we showed that Mfd prevents RNAP backtracking or rescues a severely backtracked RNAP, allowing RNAP to overcome stronger obstacles. However, if an obstacle's resistance is excessive, Mfd dissociates the RNAP, clearing the DNA for other processes. These findings demonstrate a remarkably delicate coordination between Mfd and RNAP, allowing efficient targeting and recycling of Mfd and expedient conflict resolution.
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Affiliation(s)
- Tung T Le
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA; Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - Yi Yang
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA; Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - Chuang Tan
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA; Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - Margaret M Suhanovsky
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02903, USA
| | | | - James T Inman
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA; Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - Ming Li
- Department of Chemistry, Cornell University, Ithaca, NY 14853, USA
| | - Jaeyoon Lee
- Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA
| | - Sarah Perelman
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02903, USA
| | - Jeffrey W Roberts
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Alexandra M Deaconescu
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02903, USA
| | - Michelle D Wang
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA; Physics Department & LASSP, Cornell University, Ithaca, NY 14853, USA.
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50
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Understanding nucleosome dynamics and their links to gene expression and DNA replication. Nat Rev Mol Cell Biol 2017; 18:548-562. [PMID: 28537572 DOI: 10.1038/nrm.2017.47] [Citation(s) in RCA: 309] [Impact Index Per Article: 44.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Advances in genomics technology have provided the means to probe myriad chromatin interactions at unprecedented spatial and temporal resolution. This has led to a profound understanding of nucleosome organization within the genome, revealing that nucleosomes are highly dynamic. Nucleosome dynamics are governed by a complex interplay of histone composition, histone post-translational modifications, nucleosome occupancy and positioning within chromatin, which are influenced by numerous regulatory factors, including general regulatory factors, chromatin remodellers, chaperones and polymerases. It is now known that these dynamics regulate diverse cellular processes ranging from gene transcription to DNA replication and repair.
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