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Byfield FJ, Eftekhari B, Kaymak-Loveless K, Mandal K, Li D, Wells RG, Chen W, Brujic J, Bergamaschi G, Wuite GJL, Patteson AE, Janmey PA. Metabolically intact nuclei are fluidized by the activity of the chromatin remodeling motor BRG1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.12.589275. [PMID: 38659735 PMCID: PMC11042217 DOI: 10.1101/2024.04.12.589275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The structure and dynamics of the cell nucleus regulate nearly every facet of the cell. Changes in nuclear shape limit cell motility and gene expression. Although the nucleus is generally seen as the stiffest organelle in the cell, cells can nevertheless deform the nucleus to large strains by small mechanical stresses. Here, we show that the mechanical response of the cell nucleus exhibits active fluidization that is driven by the BRG 1 motor of the SWI/SNF/BAF chromatin-remodeling complex. Atomic force microscopy measurements show that the nucleus alters stiffness in response to the cell substrate stiffness, which is retained after the nucleus is isolated and that the work of nuclear compression is mostly dissipated rather than elastically stored. Inhibiting BRG 1 stiffens the nucleus and eliminates dissipation and nuclear remodeling both in isolated nuclei and in intact cells. These findings demonstrate a novel link between nuclear motor activity and global nuclear mechanics.
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Lee JY, Bhandare RR, Boddu SHS, Shaik AB, Saktivel LP, Gupta G, Negi P, Barakat M, Singh SK, Dua K, Chellappan DK. Molecular mechanisms underlying the regulation of tumour suppressor genes in lung cancer. Biomed Pharmacother 2024; 173:116275. [PMID: 38394846 DOI: 10.1016/j.biopha.2024.116275] [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: 11/24/2023] [Revised: 01/30/2024] [Accepted: 02/13/2024] [Indexed: 02/25/2024] Open
Abstract
Tumour suppressor genes play a cardinal role in the development of a large array of human cancers, including lung cancer, which is one of the most frequently diagnosed cancers worldwide. Therefore, extensive studies have been committed to deciphering the underlying mechanisms of alterations of tumour suppressor genes in governing tumourigenesis, as well as resistance to cancer therapies. In spite of the encouraging clinical outcomes demonstrated by lung cancer patients on initial treatment, the subsequent unresponsiveness to first-line treatments manifested by virtually all the patients is inherently a contentious issue. In light of the aforementioned concerns, this review compiles the current knowledge on the molecular mechanisms of some of the tumour suppressor genes implicated in lung cancer that are either frequently mutated and/or are located on the chromosomal arms having high LOH rates (1p, 3p, 9p, 10q, 13q, and 17p). Our study identifies specific genomic loci prone to LOH, revealing a recurrent pattern in lung cancer cases. These loci, including 3p14.2 (FHIT), 9p21.3 (p16INK4a), 10q23 (PTEN), 17p13 (TP53), exhibit a higher susceptibility to LOH due to environmental factors such as exposure to DNA-damaging agents (carcinogens in cigarette smoke) and genetic factors such as chromosomal instability, genetic mutations, DNA replication errors, and genetic predisposition. Furthermore, this review summarizes the current treatment landscape and advancements for lung cancers, including the challenges and endeavours to overcome it. This review envisages inspired researchers to embark on a journey of discovery to add to the list of what was known in hopes of prompting the development of effective therapeutic strategies for lung cancer.
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Affiliation(s)
- Jia Yee Lee
- School of Health Sciences, International Medical University, Bukit Jalil, Kuala Lumpur 57000, Malaysia
| | - Richie R Bhandare
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Ajman University, Al-Jurf, P.O. Box 346, Ajman, United Arab Emirates; Center of Medical and Bio-Allied Health Sciences Research, Ajman University, Al-Jurf, P.O. Box 346, Ajman, United Arab Emirates.
| | - Sai H S Boddu
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Ajman University, Al-Jurf, P.O. Box 346, Ajman, United Arab Emirates; Center of Medical and Bio-Allied Health Sciences Research, Ajman University, Al-Jurf, P.O. Box 346, Ajman, United Arab Emirates
| | - Afzal B Shaik
- St. Mary's College of Pharmacy, St. Mary's Group of Institutions Guntur, Affiliated to Jawaharlal Nehru Technological University Kakinada, Chebrolu, Guntur, Andhra Pradesh 522212, India; Center for Global Health Research, Saveetha Medical College, Saveetha Institute of Medical and Technical Sciences, India
| | - Lakshmana Prabu Saktivel
- Department of Pharmaceutical Technology, University College of Engineering (BIT Campus), Anna University, Tiruchirappalli 620024, India
| | - Gaurav Gupta
- Center of Medical and Bio-Allied Health Sciences Research, Ajman University, Al-Jurf, P.O. Box 346, Ajman, United Arab Emirates; School of Pharmacy, Suresh Gyan Vihar University, Jaipur, Rajasthan 302017, India
| | - Poonam Negi
- School of Pharmaceutical Sciences, Shoolini University, PO Box 9, Solan, Himachal Pradesh 173229, India
| | - Muna Barakat
- Department of Clinical Pharmacy & Therapeutics, Applied Science Private University, Amman-11937, Jordan
| | - Sachin Kumar Singh
- School of Pharmaceutical Sciences, Lovely Professional University, Jalandhar-Delhi G.T Road, Phagwara 144411, India; Australian Research Centre in Complementary and Integrative Medicine, Faculty of Health, University of Technology Sydney, Sydney 2007, Australia
| | - Kamal Dua
- Australian Research Centre in Complementary and Integrative Medicine, Faculty of Health, University of Technology Sydney, Sydney 2007, Australia; Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Sydney 2007, Australia
| | - Dinesh Kumar Chellappan
- Department of Life Sciences, School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur 57000, Malaysia.
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3
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Brahma S, Henikoff S. The BAF chromatin remodeler synergizes with RNA polymerase II and transcription factors to evict nucleosomes. Nat Genet 2024; 56:100-111. [PMID: 38049663 PMCID: PMC10786724 DOI: 10.1038/s41588-023-01603-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 10/30/2023] [Indexed: 12/06/2023]
Abstract
Chromatin accessibility is a hallmark of active transcription and entails ATP-dependent nucleosome remodeling, which is carried out by complexes such as Brahma-associated factor (BAF). However, the mechanistic links between transcription, nucleosome remodeling and chromatin accessibility are unclear. Here, we used a chemical-genetic approach coupled with time-resolved chromatin profiling to dissect the interplay between RNA Polymerase II (RNAPII), BAF and DNA-sequence-specific transcription factors in mouse embryonic stem cells. We show that BAF dynamically unwraps and evicts nucleosomes at accessible chromatin regions, while RNAPII promoter-proximal pausing stabilizes BAF chromatin occupancy and enhances ATP-dependent nucleosome eviction by BAF. We find that although RNAPII and BAF dynamically probe both transcriptionally active and Polycomb-repressed genomic regions, pluripotency transcription factor chromatin binding confers locus specificity for productive chromatin remodeling and nucleosome eviction by BAF. Our study suggests a paradigm for how functional synergy between dynamically acting chromatin factors regulates locus-specific nucleosome organization and chromatin accessibility.
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Affiliation(s)
- Sandipan Brahma
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.
- Department of Genetics, Cell Biology & Anatomy, University of Nebraska Medical Center, Omaha, NE, USA.
| | - Steven Henikoff
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.
- Howard Hughes Medical Institute, Seattle, WA, USA.
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4
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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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5
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Fan H. Single‐molecule tethered particle motion to study
protein‐DNA
interaction. J CHIN CHEM SOC-TAIP 2023. [DOI: 10.1002/jccs.202300051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
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6
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Brahma S, Henikoff S. RNA Polymerase II, the BAF remodeler and transcription factors synergize to evict nucleosomes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.22.525083. [PMID: 36711459 PMCID: PMC9882304 DOI: 10.1101/2023.01.22.525083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Chromatin accessibility is a hallmark of active transcription and requires ATP-dependent nucleosome remodeling by Brahma-Associated Factor (BAF). However, the mechanistic link between transcription, nucleosome remodeling, and chromatin accessibility is unclear. Here, we used a chemical-genetic approach to dissect the interplay between RNA Polymerase II (RNAPII), BAF, and DNA-sequence-specific transcription factors (TFs) in mouse embryonic stem cells. By time-resolved chromatin profiling with acute transcription block at distinct stages, we show that RNAPII promoter-proximal pausing stabilizes BAF chromatin occupancy and enhances nucleosome eviction by BAF. We find that RNAPII and BAF probe both transcriptionally active and Polycomb-repressed genomic regions and provide evidence that TFs capture transient site exposure due to nucleosome unwrapping by BAF to confer locus specificity for persistent chromatin remodeling. Our study reveals the mechanistic basis of cell-type-specific chromatin accessibility. We propose a new paradigm for how functional synergy between dynamically acting chromatin factors regulates nucleosome organization.
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Affiliation(s)
- Sandipan Brahma
- Basic Sciences Division, Fred Hutchinson Cancer Center, 1100 Fairview Ave North, Seattle, WA, 98109
| | - Steven Henikoff
- Basic Sciences Division, Fred Hutchinson Cancer Center, 1100 Fairview Ave North, Seattle, WA, 98109
- Howard Hughes Medical Institute, USA
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7
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Abstract
In anaphase, any unresolved DNA entanglements between the segregating sister chromatids can give rise to chromatin bridges. To prevent genome instability, chromatin bridges must be resolved prior to cytokinesis. The SNF2 protein PICH has been proposed to play a direct role in this process through the remodeling of nucleosomes. However, direct evidence of nucleosome remodeling by PICH has remained elusive. Here, we present an in vitro single-molecule assay that mimics chromatin under tension, as is found in anaphase chromatin bridges. Applying a combination of dual-trap optical tweezers and fluorescence imaging of PICH and histones bound to a nucleosome-array construct, we show that PICH is a tension- and ATP-dependent nucleosome remodeler that facilitates nucleosome unwrapping and then subsequently slides remaining histones along the DNA. This work elucidates the role of PICH in chromatin-bridge dissolution, and might provide molecular insights into the mechanisms of related SNF2 proteins.
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8
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Zhou M. DNA sliding and loop formation by E. coli SMC complex: MukBEF. Biochem Biophys Rep 2022; 31:101297. [PMID: 35770038 PMCID: PMC9234588 DOI: 10.1016/j.bbrep.2022.101297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/08/2022] [Accepted: 06/06/2022] [Indexed: 11/29/2022] Open
Abstract
SMC (structural maintenance of chromosomes) complexes share conserved architectures and function in chromosome maintenance via an unknown mechanism. Here we have used single-molecule techniques to study MukBEF, the SMC complex in Escherichia coli. Real-time movies show MukB alone can compact DNA and ATP inhibits DNA compaction by MukB. We observed that DNA unidirectionally slides through MukB, potentially by a ratchet mechanism, and the sliding speed depends on the elastic energy stored in the DNA. MukE, MukF and ATP binding stabilize MukB and DNA interaction, and ATP hydrolysis regulates the loading/unloading of MukBEF from DNA. Our data suggests a new model for how MukBEF organizes the bacterial chromosome in vivo; and this model will be relevant for other SMC proteins. ATP-independent DNA compaction by MukB. DNA unidirectionally slides through MukB, potentially by a ratchet mechanism. MukE, MukF and ATP binding stabilize MukB and DNA interaction. DNA sliding via ratchet driven by entropic force model for chromosome organization by SMC complex.
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Partitioned usage of chromatin remodelers by nucleosome-displacing factors. Cell Rep 2022; 40:111250. [PMID: 36001970 PMCID: PMC9422437 DOI: 10.1016/j.celrep.2022.111250] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/29/2022] [Accepted: 08/01/2022] [Indexed: 11/22/2022] Open
Abstract
Nucleosome-displacing-factors (NDFs) in yeast, similar to pioneer factors in higher eukaryotes, can open closed chromatin and generate nucleosome-depleted regions (NDRs). NDRs in yeast are also affected by ATP-dependent chromatin remodelers (CRs). However, how NDFs and CRs coordinate in nucleosome invasion and NDR formation is still unclear. Here, we design a high-throughput method to systematically study the interplay between NDFs and CRs. By combining an integrated synthetic oligonucleotide library with DNA methyltransferase-based, single-molecule nucleosome mapping, we measure the impact of CRs on NDRs generated by individual NDFs. We find that CRs are dispensable for nucleosome invasion by NDFs, and they function downstream of NDF binding to modulate the NDR length. A few CRs show high specificity toward certain NDFs; however, in most cases, CRs are recruited in a factor-nonspecific and NDR length-dependent manner. Overall, our study provides a framework to investigate how NDFs and CRs cooperate to regulate chromatin opening. Chromatin accessibility in yeast is regulated by nucleosome-displacing-factors (NDFs) and chromatin remodelers (CRs). Chen et al. show that NDFs first invade into nucleosomes and then recruit CRs to modulate the NDR length. NDF-specific and NDR length-dependent recruitment of CRs allow partitioned usage of CRs by NDFs.
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10
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Bylino OV, Ibragimov AN, Digilio FA, Giordano E, Shidlovskii YV. Application of the 3C Method to Study the Developmental Genes in Drosophila Larvae. Front Genet 2022; 13:734208. [PMID: 35910225 PMCID: PMC9335292 DOI: 10.3389/fgene.2022.734208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 06/08/2022] [Indexed: 11/13/2022] Open
Abstract
A transition from one developmental stage to another is accompanied by activation of developmental programs and corresponding gene ensembles. Changes in the spatial conformation of the corresponding loci are associated with this activation and can be investigated with the help of the Chromosome Conformation Capture (3C) methodology. Application of 3C to specific developmental stages is a sophisticated task. Here, we describe the use of the 3C method to study the spatial organization of developmental loci in Drosophila larvae. We critically analyzed the existing protocols and offered our own solutions and the optimized protocol to overcome limitations. To demonstrate the efficiency of our procedure, we studied the spatial organization of the developmental locus Dad in 3rd instar Drosophila larvae. Differences in locus conformation were found between embryonic cells and living wild-type larvae. We also observed the establishment of novel regulatory interactions in the presence of an adjacent transgene upon activation of its expression in larvae. Our work fills the gap in the application of the 3C method to Drosophila larvae and provides a useful guide for establishing 3C on an animal model.
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Affiliation(s)
- Oleg V. Bylino
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Airat N. Ibragimov
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | | | - Ennio Giordano
- Department of Biology, Università di Napoli Federico II, Naples, Italy
| | - Yulii V. Shidlovskii
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- Department of Biology and General Genetics, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
- *Correspondence: Yulii V. Shidlovskii,
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11
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Peng A, Peng W, Wang R, Zhao H, Yu X, Sun Y. Regulation of 3D Organization and Its Role in Cancer Biology. Front Cell Dev Biol 2022; 10:879465. [PMID: 35757006 PMCID: PMC9213882 DOI: 10.3389/fcell.2022.879465] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 04/27/2022] [Indexed: 11/13/2022] Open
Abstract
Three-dimensional (3D) genomics is the frontier field in the post-genomics era, its foremost content is the relationship between chromatin spatial conformation and regulation of gene transcription. Cancer biology is a complex system resulting from genetic alterations in key tumor oncogenes and suppressor genes for cell proliferation, DNA replication, cell differentiation, and homeostatic functions. Although scientific research in recent decades has revealed how the genome sequence is mutated in many cancers, high-order chromosomal structures involved in the development and fate of cancer cells represent a crucial but rarely explored aspect of cancer genomics. Hence, dissection of the 3D genome conformation of cancer helps understand the unique epigenetic patterns and gene regulation processes that distinguish cancer biology from normal physiological states. In recent years, research in tumor 3D genomics has grown quickly. With the rapid progress of 3D genomics technology, we can now better determine the relationship between cancer pathogenesis and the chromatin structure of cancer cells. It is becoming increasingly explicit that changes in 3D chromatin structure play a vital role in controlling oncogene transcription. This review focuses on the relationships between tumor gene expression regulation, tumor 3D chromatin structure, and cancer phenotypic plasticity. Furthermore, based on the functional consequences of spatial disorganization in the cancer genome, we look forward to the clinical application prospects of 3D genomic biomarkers.
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Affiliation(s)
- Anghui Peng
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China.,Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment, Zhuhai Institute of Translational Medicine, Zhuhai People's Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
| | - Wang Peng
- Department of Oncology, Liuzhou People's Hospital, Liuzhou, China
| | - Ruiqi Wang
- Department of Pharmacy, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
| | - Hao Zhao
- The First College of Clinical Medical Science, China Three Gorges University, Yichang, China
| | - Xinyang Yu
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China.,Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment, Zhuhai Institute of Translational Medicine, Zhuhai People's Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
| | - Yihao Sun
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China.,Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment, Zhuhai Institute of Translational Medicine, Zhuhai People's Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
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12
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Kenworthy CA, Haque N, Liou SH, Chandris P, Wong V, Dziuba P, Lavis LD, Liu WL, Singer RH, Coleman RA. Bromodomains regulate dynamic targeting of the PBAF chromatin-remodeling complex to chromatin hubs. Biophys J 2022; 121:1738-1752. [PMID: 35364106 PMCID: PMC9117891 DOI: 10.1016/j.bpj.2022.03.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/20/2021] [Accepted: 03/24/2022] [Indexed: 11/12/2022] Open
Abstract
Chromatin remodelers actively target arrays of acetylated nucleosomes at select enhancers and promoters to facilitate or shut down the repeated recruitment of RNA polymerase II during transcriptional bursting. It is poorly understood how chromatin remodelers such as PBAF dynamically target different chromatin states inside a live cell. Our live-cell single-molecule fluorescence microscopy study reveals chromatin hubs throughout the nucleus where PBAF rapidly cycles on and off the genome. Deletion of PBAF's bromodomains impairs targeting and stable engagement of chromatin in hubs. Dual color imaging reveals that PBAF targets both euchromatic and heterochromatic hubs with distinct genome-binding kinetic profiles that mimic chromatin stability. Removal of PBAF's bromodomains stabilizes H3.3 binding within chromatin, indicating that bromodomains may play a direct role in remodeling of the nucleosome. Our data suggests that PBAF's dynamic bromodomain-mediated engagement of a nucleosome may reflect the chromatin-remodeling potential of differentially bound chromatin states.
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Affiliation(s)
- Charles A Kenworthy
- Gruss-Lipper Biophotonics Center, Department of Cell Biology, Albert Einstein College of Medicine, New York
| | - Nayem Haque
- Gruss-Lipper Biophotonics Center, Department of Cell Biology, Albert Einstein College of Medicine, New York
| | - Shu-Hao Liou
- Gruss-Lipper Biophotonics Center, Department of Cell Biology, Albert Einstein College of Medicine, New York
| | - Panagiotis Chandris
- Section on High Resolution Optical Imaging, National Institute on Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland
| | - Vincent Wong
- Gruss-Lipper Biophotonics Center, Department of Cell Biology, Albert Einstein College of Medicine, New York
| | - Patrycja Dziuba
- Gruss-Lipper Biophotonics Center, Department of Cell Biology, Albert Einstein College of Medicine, New York
| | - Luke D Lavis
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia
| | - Wei-Li Liu
- Gruss-Lipper Biophotonics Center, Department of Cell Biology, Albert Einstein College of Medicine, New York
| | - Robert H Singer
- Gruss-Lipper Biophotonics Center, Department of Cell Biology, Albert Einstein College of Medicine, New York; Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia
| | - Robert A Coleman
- Gruss-Lipper Biophotonics Center, Department of Cell Biology, Albert Einstein College of Medicine, New York.
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13
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Dong C, Zhang R, Xu L, Liu B, Chu X. Assembly and interaction of core subunits of BAF complexes and crystal study of the SMARCC1/SMARCE1 binary complex. Biochem Biophys Res Commun 2022; 599:9-16. [DOI: 10.1016/j.bbrc.2022.02.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 02/02/2022] [Indexed: 01/20/2023]
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14
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Kito Y, Kawashima K, Saigo C, Hasegawa M, Nomura S, Mikamo T, Hanamatsu Y, Matsuo Y, Takeuchi T. Thorahcic SMARCA4-deficient undifferentiated tumors with ganglioneuroma and enchondroma: implications for SLC7A11 and ARID1A expression: a case report. Diagn Pathol 2022; 17:29. [PMID: 35151345 PMCID: PMC8840641 DOI: 10.1186/s13000-022-01205-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 01/25/2022] [Indexed: 11/24/2022] Open
Abstract
Background SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 4-deficient thoracic sarcoma (SMARCA4-DTS) is a rare disease that has recently been described as an entity. It is characterized by an aggressive clinical course and specific genetic alterations. As an immunohistological feature, the tumors are deficient in SMARCA4 and SMARCA2 and express sex-determining region Y (SRY)-box 2 (SOX2). Occasionally, there are cases that are less frequent and difficult to distinguish from SMARCA4-deficient non-small cell lung carcinoma (SMARCA4-dNSCLC). Therefore, the 5th edition of the World Health Organization (WHO) classification describes thoracic SMARCA 4-deficient undifferentiated tumors (SMARCA4-UT). In contrast, Carney’s triad is a syndrome that combines three rare soft tissue tumors: gastric leiomyosarcoma, pulmonary chondroma, and extra-adrenal paraganglioma. Protein kinase cAMP-dependent type I regulatory subunit alpha (PRKAR1A) has been proposed as the causative gene. Both diseases are valuable cases; moreover, there have been no previous reports of their coexistence. Case presentation A 43-year-old man visited our hospital because of respiratory distress. Computed tomography revealed a large mass measuring 55 mm in the upper lobe of the right lung and front mediastinum, with metastases in the surrounding lymph nodes. Needle biopsy was performed for diagnosis, and histological examination of the samples revealed monotonous epithelioid-like cells with loose binding and sheet-form proliferation. The tumor cells had distinct nuclei with some rhabdoid-like cells. Immunohistochemical analysis revealed that the tumor cells were positive for AE1AE3, SOX2, CD34, and p53 and negative for SMARCA4 and SMARCA2. The patient died 6 months after admission, without any treatment. Autopsy revealed ganglioneuroma and enchondroma suggestive of an incomplete Carney complex. Conclusion SMARCA4-UT is a rare and recently established disease. While it is difficult to diagnose, it is necessary to distinguish undifferentiated carcinoma, large cell carcinoma, Ewing sarcoma, and epithelioid sarcoma when diagnosing tumors involving the mediastinum. Moreover, cases of SMARCA4-UT with ganglioneuroma and enchondroma are very rare. We discuss and report a case of SMARCA4-UT in which we also examined ARID1A and SLC7A11expression.
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15
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Kuzmina NS. Radiation-Induced DNA Methylation Disorders: In Vitro and In Vivo Studies. BIOL BULL+ 2022. [DOI: 10.1134/s1062359021110066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Ma L, Ge J, Bian X, Zhang Y. Single-Molecule Optical Tweezers Study of Protein-Membrane Interactions. Methods Mol Biol 2022; 2473:367-383. [PMID: 35819776 DOI: 10.1007/978-1-0716-2209-4_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Numerous proteins directly or indirectly bind membranes to exert their roles in a wide variety of biological processes. Such membrane binding often occurs in the presence of an external mechanical force. It remains challenging to quantify these interactions using traditional experimental approaches based on a large number of molecules, due to ensemble averaging or the lack of mechanical force. Here we described a new single-molecule approach based on high-resolution optical tweezers to characterize protein-membrane interactions. A single membrane binding protein is attached to the lipid bilayer coated on a silica bead via a flexible polypeptide linker, tethered to another bead via a long DNA handle, and pulled away from the bilayer using optical tweezers. Dynamic protein binding and unbinding is detected by the corresponding changes in the extension of the protein-DNA tether with high spatiotemporal resolution, which reveals the membrane binding affinity, kinetics, and intermediates. We demonstrated the method using C2 domains of extended synaptotagmin 2 (E-Syt2) with a detailed protocol. The method can be widely applied to investigate complex protein-membrane interactions under well-controlled experimental conditions.
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Affiliation(s)
- Lu Ma
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Jinghua Ge
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Xin Bian
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Yongli Zhang
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.
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17
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Blümli S, Wiechens N, Wu MY, Singh V, Gierlinski M, Schweikert G, Gilbert N, Naughton C, Sundaramoorthy R, Varghese J, Gourlay R, Soares R, Clark D, Owen-Hughes T. Acute depletion of the ARID1A subunit of SWI/SNF complexes reveals distinct pathways for activation and repression of transcription. Cell Rep 2021; 37:109943. [PMID: 34731603 PMCID: PMC8578704 DOI: 10.1016/j.celrep.2021.109943] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 07/05/2021] [Accepted: 10/13/2021] [Indexed: 11/30/2022] Open
Abstract
The ARID1A subunit of SWI/SNF chromatin remodeling complexes is a potent tumor suppressor. Here, a degron is applied to detect rapid loss of chromatin accessibility at thousands of loci where ARID1A acts to generate accessible minidomains of nucleosomes. Loss of ARID1A also results in the redistribution of the coactivator EP300. Co-incident EP300 dissociation and lost chromatin accessibility at enhancer elements are highly enriched adjacent to rapidly downregulated genes. In contrast, sites of gained EP300 occupancy are linked to genes that are transcriptionally upregulated. These chromatin changes are associated with a small number of genes that are differentially expressed in the first hours following loss of ARID1A. Indirect or adaptive changes dominate the transcriptome following growth for days after loss of ARID1A and result in strong engagement with cancer pathways. The identification of this hierarchy suggests sites for intervention in ARID1A-driven diseases. Degradation of ARID1A disrupts nucleosomes flanking pluripotency transcription factors EP300 is rapidly redistributed with increased occupancy adjacent to upregulated genes These changes are associated with misregulation of a few hundred genes within 2 h During subsequent days, widespread indirect changes mimic a premalignant state
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Affiliation(s)
- Seraina Blümli
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Nicola Wiechens
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Meng-Ying Wu
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Vijender Singh
- Computational Core, University of Connecticut, 67 North Eagleville Road, Storrs, CT 06269, USA
| | - Marek Gierlinski
- Computational Biology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Gabriele Schweikert
- Computational Biology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Nick Gilbert
- MRC Human Genetics Unit, Institute of Genetics & Cancer, The University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Catherine Naughton
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, UK
| | | | - Joby Varghese
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, UK
| | - Robert Gourlay
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, UK
| | - Renata Soares
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, UK
| | - David Clark
- Division of Developmental Biology, National Institute of Child Health and Human Development, NIH, Building 6A, 6 Centre Drive, Bethesda, MD 20892, USA
| | - Tom Owen-Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
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18
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Tilly BC, Chalkley GE, van der Knaap JA, Moshkin YM, Kan TW, Dekkers DH, Demmers JA, Verrijzer CP. In vivo analysis reveals that ATP-hydrolysis couples remodeling to SWI/SNF release from chromatin. eLife 2021; 10:69424. [PMID: 34313222 PMCID: PMC8352592 DOI: 10.7554/elife.69424] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/26/2021] [Indexed: 12/23/2022] Open
Abstract
ATP-dependent chromatin remodelers control the accessibility of genomic DNA through nucleosome mobilization. However, the dynamics of genome exploration by remodelers, and the role of ATP hydrolysis in this process remain unclear. We used live-cell imaging of Drosophila polytene nuclei to monitor Brahma (BRM) remodeler interactions with its chromosomal targets. In parallel, we measured local chromatin condensation and its effect on BRM association. Surprisingly, only a small portion of BRM is bound to chromatin at any given time. BRM binds decondensed chromatin but is excluded from condensed chromatin, limiting its genomic search space. BRM-chromatin interactions are highly dynamic, whereas histone-exchange is limited and much slower. Intriguingly, loss of ATP hydrolysis enhanced chromatin retention and clustering of BRM, which was associated with reduced histone turnover. Thus, ATP hydrolysis couples nucleosome remodeling to remodeler release, driving a continuous transient probing of the genome.
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Affiliation(s)
- Ben C Tilly
- Department of Biochemistry, Rotterdam, Netherlands
| | | | | | | | | | - Dick Hw Dekkers
- Department of Biochemistry, Rotterdam, Netherlands.,Proteomics Center, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Jeroen Aa Demmers
- Department of Biochemistry, Rotterdam, Netherlands.,Proteomics Center, Erasmus University Medical Center, Rotterdam, Netherlands
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19
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Actin-Related Protein 6 (Arp6) Influences Double-Strand Break Repair in Yeast. Appl Microbiol 2021. [DOI: 10.3390/applmicrobiol1020017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
DNA double-strand breaks (DSBs) are the most deleterious form of DNA damage and are repaired through non-homologous end-joining (NHEJ) or homologous recombination (HR). Repair initiation, regulation and communication with signaling pathways require several histone-modifying and chromatin-remodeling complexes. In budding yeast, this involves three primary complexes: INO80-C, which is primarily associated with HR, SWR1-C, which promotes NHEJ, and RSC-C, which is involved in both pathways as well as the general DNA damage response. Here we identify ARP6 as a factor involved in DSB repair through an RSC-C-related pathway. The loss of ARP6 significantly reduces the NHEJ repair efficiency of linearized plasmids with cohesive ends, impairs the repair of chromosomal breaks, and sensitizes cells to DNA-damaging agents. Genetic interaction analysis indicates that ARP6, MRE11 and RSC-C function within the same pathway, and the overexpression of ARP6 rescues rsc2∆ and mre11∆ sensitivity to DNA-damaging agents. Double mutants of ARP6, and members of the INO80 and SWR1 complexes, cause a significant reduction in repair efficiency, suggesting that ARP6 functions independently of SWR1-C and INO80-C. These findings support a novel role for ARP6 in DSB repair that is independent of the SWR1 chromatin remodeling complex, through an apparent RSC-C and MRE11-associated DNA repair pathway.
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20
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Rudnizky S, Khamis H, Ginosar Y, Goren E, Melamed P, Kaplan A. Extended and dynamic linker histone-DNA Interactions control chromatosome compaction. Mol Cell 2021; 81:3410-3421.e4. [PMID: 34192510 DOI: 10.1016/j.molcel.2021.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 06/01/2021] [Accepted: 06/03/2021] [Indexed: 02/06/2023]
Abstract
Chromatosomes play a fundamental role in chromatin regulation, but a detailed understanding of their structure is lacking, partially due to their complex dynamics. Using single-molecule DNA unzipping with optical tweezers, we reveal that linker histone interactions with DNA are remarkably extended, with the C-terminal domain binding both DNA linkers as far as approximately ±140 bp from the dyad. In addition to a symmetrical compaction of the nucleosome core governed by globular domain contacts at the dyad, the C-terminal domain compacts the nucleosome's entry and exit. These interactions are dynamic, exhibit rapid binding and dissociation, are sensitive to phosphorylation of a specific residue, and are crucial to determining the symmetry of the chromatosome's core. Extensive unzipping of the linker DNA, which mimics its invasion by motor proteins, shifts H1 into an asymmetric, off-dyad configuration and triggers nucleosome decompaction, highlighting the plasticity of the chromatosome structure and its potential regulatory role.
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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
| | - Yuval Ginosar
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Efrat Goren
- Faculty of Biology, 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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21
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Song Y, Hyeon C. Thermodynamic uncertainty relation to assess biological processes. J Chem Phys 2021; 154:130901. [PMID: 33832251 DOI: 10.1063/5.0043671] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
We review the trade-offs between speed, fluctuations, and thermodynamic cost involved with biological processes in nonequilibrium states and discuss how optimal these processes are in light of the universal bound set by the thermodynamic uncertainty relation (TUR). The values of the uncertainty product Q of TUR, which can be used as a measure of the precision of enzymatic processes realized for a given thermodynamic cost, are suboptimal when the substrate concentration is at the Michaelis constant, and some of the key biological processes are found to work around this condition. We illustrate the utility of Q in assessing how close the molecular motors and biomass producing machineries are to the TUR bound, and for the cases of biomass production (or biological copying processes), we discuss how their optimality quantified in terms of Q is balanced with the error rate in the information transfer process. We also touch upon the trade-offs in other error-minimizing processes in biology, such as gene regulation and chaperone-assisted protein folding. A spectrum of Q recapitulating the biological processes surveyed here provides glimpses into how biological systems are evolved to optimize and balance the conflicting functional requirements.
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Affiliation(s)
- Yonghyun Song
- Korea Institute for Advanced Study, Seoul 02455, South Korea
| | - Changbong Hyeon
- Korea Institute for Advanced Study, Seoul 02455, South Korea
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22
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Shidlovskii YV, Bylino OV, Shaposhnikov AV, Kachaev ZM, Lebedeva LA, Kolesnik VV, Amendola D, De Simone G, Formicola N, Schedl P, Digilio FA, Giordano E. Subunits of the PBAP Chromatin Remodeler Are Capable of Mediating Enhancer-Driven Transcription in Drosophila. Int J Mol Sci 2021; 22:ijms22062856. [PMID: 33799739 PMCID: PMC7999800 DOI: 10.3390/ijms22062856] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/03/2021] [Accepted: 03/08/2021] [Indexed: 12/11/2022] Open
Abstract
The chromatin remodeler SWI/SNF is an important participant in gene activation, functioning predominantly by opening the chromatin structure on promoters and enhancers. Here, we describe its novel mode of action in which SWI/SNF factors mediate the targeted action of an enhancer. We studied the functions of two signature subunits of PBAP subfamily, BAP170 and SAYP, in Drosophila. These subunits were stably tethered to a transgene reporter carrying the hsp70 core promoter. The tethered subunits mediate transcription of the reporter in a pattern that is generated by enhancers close to the insertion site in multiple loci throughout the genome. Both tethered SAYP and BAP170 recruit the whole PBAP complex to the reporter promoter. However, we found that BAP170-dependent transcription is more resistant to the depletion of other PBAP subunits, suggesting that BAP170 may play a more critical role in establishing enhancer-dependent transcription.
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Affiliation(s)
- Yulii V. Shidlovskii
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (O.V.B.); (A.V.S.); (Z.M.K.); (L.A.L.); (V.V.K.); (P.S.)
- Center for Genetics and Life Science, Sirius University of Science and Technology, 354340 Sochi, Russia
- Department of Biology and General Genetics, Sechenov First Moscow State Medical University (Sechenov University), 119992 Moscow, Russia
- Correspondence: (Y.V.S.); (F.A.D.); (E.G.)
| | - Oleg V. Bylino
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (O.V.B.); (A.V.S.); (Z.M.K.); (L.A.L.); (V.V.K.); (P.S.)
| | - Alexander V. Shaposhnikov
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (O.V.B.); (A.V.S.); (Z.M.K.); (L.A.L.); (V.V.K.); (P.S.)
| | - Zaur M. Kachaev
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (O.V.B.); (A.V.S.); (Z.M.K.); (L.A.L.); (V.V.K.); (P.S.)
- Center for Genetics and Life Science, Sirius University of Science and Technology, 354340 Sochi, Russia
| | - Lyubov A. Lebedeva
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (O.V.B.); (A.V.S.); (Z.M.K.); (L.A.L.); (V.V.K.); (P.S.)
| | - Valeria V. Kolesnik
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (O.V.B.); (A.V.S.); (Z.M.K.); (L.A.L.); (V.V.K.); (P.S.)
| | - Diego Amendola
- Department of Biology, Università di Napoli Federico II, 80138 Naples, Italy; (D.A.); (G.D.S.)
| | - Giovanna De Simone
- Department of Biology, Università di Napoli Federico II, 80138 Naples, Italy; (D.A.); (G.D.S.)
- Department of Sciences, Roma Tre University, 00154 Rome, Italy
| | - Nadia Formicola
- Institute of Research on Terrestrial Ecosystems (IRET) National Research Council (CNR), 05010 Porano, Italy;
- Institut de Biologie Valrose iBV UMR CNRS 7277, Université Côte d’Azur, 06108 Nice, France
| | - Paul Schedl
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (O.V.B.); (A.V.S.); (Z.M.K.); (L.A.L.); (V.V.K.); (P.S.)
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544-1014, USA
| | - Filomena Anna Digilio
- Institute of Research on Terrestrial Ecosystems (IRET) National Research Council (CNR), 05010 Porano, Italy;
- Correspondence: (Y.V.S.); (F.A.D.); (E.G.)
| | - Ennio Giordano
- Department of Biology, Università di Napoli Federico II, 80138 Naples, Italy; (D.A.); (G.D.S.)
- Correspondence: (Y.V.S.); (F.A.D.); (E.G.)
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23
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Wolff MR, Schmid A, Korber P, Gerland U. Effective dynamics of nucleosome configurations at the yeast PHO5 promoter. eLife 2021; 10:58394. [PMID: 33666171 PMCID: PMC8004102 DOI: 10.7554/elife.58394] [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: 04/29/2020] [Accepted: 03/04/2021] [Indexed: 12/11/2022] Open
Abstract
Chromatin dynamics are mediated by remodeling enzymes and play crucial roles in gene regulation, as established in a paradigmatic model, the Saccharomyces cerevisiae PHO5 promoter. However, effective nucleosome dynamics, that is, trajectories of promoter nucleosome configurations, remain elusive. Here, we infer such dynamics from the integration of published single-molecule data capturing multi-nucleosome configurations for repressed to fully active PHO5 promoter states with other existing histone turnover and new chromatin accessibility data. We devised and systematically investigated a new class of 'regulated on-off-slide' models simulating global and local nucleosome (dis)assembly and sliding. Only seven of 68,145 models agreed well with all data. All seven models involve sliding and the known central role of the N-2 nucleosome, but regulate promoter state transitions by modulating just one assembly rather than disassembly process. This is consistent with but challenges common interpretations of previous observations at the PHO5 promoter and suggests chromatin opening by binding competition.
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Affiliation(s)
| | - Andrea Schmid
- Molecular Biology Division, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Philipp Korber
- Molecular Biology Division, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Ulrich Gerland
- Department of Physics, Technical University of Munich, Garching, Germany
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24
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Neumann H, Wilkins BJ. Spanning the gap: unraveling RSC dynamics in vivo. Curr Genet 2021; 67:399-406. [PMID: 33484328 PMCID: PMC8139908 DOI: 10.1007/s00294-020-01144-1] [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: 10/23/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 11/17/2022]
Abstract
Multiple reports over the past 2 years have provided the first complete structural analyses for the essential yeast chromatin remodeler, RSC, providing elaborate molecular details for its engagement with the nucleosome. However, there still remain gaps in resolution, particularly within the many RSC subunits that harbor histone binding domains. Solving contacts at these interfaces is crucial because they are regulated by posttranslational modifications that control remodeler binding modes and function. Modifications are dynamic in nature often corresponding to transcriptional activation states and cell cycle stage, highlighting not only a need for enriched spatial resolution but also temporal understanding of remodeler engagement with the nucleosome. Our recent work sheds light on some of those gaps by exploring the binding interface between the RSC catalytic motor protein, Sth1, and the nucleosome, in the living nucleus. Using genetically encoded photo-activatable amino acids incorporated into histones of living yeast we are able to monitor the nucleosomal binding of RSC, emphasizing the regulatory roles of histone modifications in a spatiotemporal manner. We observe that RSC prefers to bind H2B SUMOylated nucleosomes in vivo and interacts with neighboring nucleosomes via H3K14ac. Additionally, we establish that RSC is constitutively bound to the nucleosome and is not ejected during mitotic chromatin compaction but alters its binding mode as it progresses through the cell cycle. Our data offer a renewed perspective on RSC mechanics under true physiological conditions.
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Affiliation(s)
- Heinz Neumann
- Department of Structural Biochemistry, Max-Planck-Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227, Dortmund, Germany. .,Department of Chemical Engineering and Biotechnology, University of Applied Sciences Darmstadt, Stephanstrasse 7, 64295, Darmstadt, Germany.
| | - Bryan J Wilkins
- Department of Chemistry and Biochemistry, Manhattan College, 4513 Manhattan College Parkway, Bronx, NY, 10471, USA.
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25
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Marr LT, Ocampo J, Clark DJ, Hayes JJ. Global histone protein surface accessibility in yeast indicates a uniformly loosely packed genome with canonical nucleosomes. Epigenetics Chromatin 2021; 14:5. [PMID: 33430969 PMCID: PMC7802155 DOI: 10.1186/s13072-020-00381-5] [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: 09/01/2020] [Accepted: 12/28/2020] [Indexed: 01/09/2023] Open
Abstract
Background The vast majority of methods available to characterize genome-wide chromatin structure exploit differences in DNA accessibility to nucleases or chemical crosslinking. We developed a novel method to gauge genome-wide accessibility of histone protein surfaces within nucleosomes by assessing reactivity of engineered cysteine residues with a thiol-specific reagent, biotin-maleimide (BM). Results Yeast nuclei were obtained from cells expressing the histone mutant H2B S116C, in which a cysteine resides near the center of the external flat protein surface of the nucleosome. BM modification revealed that nucleosomes are generally equivalently accessible throughout the S. cerevisiae genome, including heterochromatic regions, suggesting limited, higher-order chromatin structures in which this surface is obstructed by tight nucleosome packing. However, we find that nucleosomes within 500 bp of transcription start sites exhibit the greatest range of accessibility, which correlates with the density of chromatin remodelers. Interestingly, accessibility is not well correlated with RNA polymerase density and thus the level of gene expression. We also investigated the accessibility of cysteine mutations designed to detect exposure of histone surfaces internal to the nucleosome thought to be accessible in actively transcribed genes: H3 102, is at the H2A–H2B dimer/H3–H4 tetramer interface, and H3 A110C, resides at the H3–H3 interface. However, in contrast to the external surface site, we find that neither of these internal sites were found to be appreciably exposed. Conclusions Overall, our finding that nucleosomes surfaces within S. cerevisiae chromatin are equivalently accessible genome-wide is consistent with a globally uncompacted chromatin structure lacking substantial higher-order organization. However, we find modest differences in accessibility that correlate with chromatin remodelers but not transcription, suggesting chromatin poised for transcription is more accessible than actively transcribed or intergenic regions. In contrast, we find that two internal sites remain inaccessible, suggesting that such non-canonical nucleosome species generated during transcription are rapidly and efficiently converted to canonical nucleosome structure and thus not widely present in native chromatin.
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Affiliation(s)
- Luke T Marr
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Josefina Ocampo
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), C1428ADN, Buenos Aires, Argentina
| | - David J Clark
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, 20892, USA
| | - Jeffrey J Hayes
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY, 14642, USA.
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26
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Abstract
As primary carriers of epigenetic information and gatekeepers of genomic DNA, nucleosomes are essential for proper growth and development of all eukaryotic cells. Although they are intrinsically dynamic, nucleosomes are actively reorganized by ATP-dependent chromatin remodelers. Chromatin remodelers contain helicase-like ATPase motor domains that can translocate along DNA, and a long-standing question in the field is how this activity is used to reposition or slide nucleosomes. In addition to ratcheting along DNA like their helicase ancestors, remodeler ATPases appear to dictate specific alternating geometries of the DNA duplex, providing an unexpected means for moving DNA past the histone core. Emerging evidence supports twist-based mechanisms for ATP-driven repositioning of nucleosomes along DNA. In this review, we discuss core experimental findings and ideas that have shaped the view of how nucleosome sliding may be achieved.
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Affiliation(s)
- Ilana M Nodelman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA;
| | - Gregory D Bowman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA;
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27
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Morgan A, LeGresley S, Fischer C. Remodeler Catalyzed Nucleosome Repositioning: Influence of Structure and Stability. Int J Mol Sci 2020; 22:ijms22010076. [PMID: 33374740 PMCID: PMC7793527 DOI: 10.3390/ijms22010076] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/04/2020] [Accepted: 12/16/2020] [Indexed: 02/06/2023] Open
Abstract
The packaging of the eukaryotic genome into chromatin regulates the storage of genetic information, including the access of the cell’s DNA metabolism machinery. Indeed, since the processes of DNA replication, translation, and repair require access to the underlying DNA, several mechanisms, both active and passive, have evolved by which chromatin structure can be regulated and modified. One mechanism relies upon the function of chromatin remodeling enzymes which couple the free energy obtained from the binding and hydrolysis of ATP to the mechanical work of repositioning and rearranging nucleosomes. Here, we review recent work on the nucleosome mobilization activity of this essential family of molecular machines.
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28
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Kirk J, Lee JY, Lee Y, Kang C, Shin S, Lee E, Song JJ, Hohng S. Yeast Chd1p Unwraps the Exit Side DNA upon ATP Binding to Facilitate the Nucleosome Translocation Occurring upon ATP Hydrolysis. Biochemistry 2020; 59:4481-4487. [PMID: 33174727 DOI: 10.1021/acs.biochem.0c00747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chromodomain-helicase-DNA-binding protein 1 (CHD1) remodels chromatin by translocating nucleosomes along DNA, but its mechanism remains poorly understood. We use single-molecule fluorescence experiments to clarify the mechanism by which yeast CHD1 (Chd1p) remodels nucleosomes. We find that binding of ATP to Chd1p induces transient unwrapping of the DNA on the exit side of the nucleosome, facilitating nucleosome translocation. ATP hydrolysis is required to induce nucleosome translocation. The unwrapped DNA after translocation is then rewrapped after the release of the hydrolyzed nucleotide and phosphate, revealing that each step of the ATP hydrolysis cycle is responsible for a distinct step of nucleosome remodeling. These results show that Chd1p remodels nucleosomes via a mechanism that is unique among the other ATP-dependent chromatin remodelers.
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Affiliation(s)
- Jaewon Kirk
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Ju Yeon Lee
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Yejin Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Chanshin Kang
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Soochul Shin
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Eunhye Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Ji-Joon Song
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Sungchul Hohng
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
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Sonar P, Bellucci L, Mossa A, Heidarsson PO, Kragelund BB, Cecconi C. Effects of Ligand Binding on the Energy Landscape of Acyl-CoA-Binding Protein. Biophys J 2020; 119:1821-1832. [PMID: 33080224 PMCID: PMC7677128 DOI: 10.1016/j.bpj.2020.09.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/14/2020] [Accepted: 09/08/2020] [Indexed: 12/19/2022] Open
Abstract
Binding of ligands is often crucial for function yet the effects of ligand binding on the mechanical stability and energy landscape of proteins are incompletely understood. Here, we use a combination of single-molecule optical tweezers and MD simulations to investigate the effect of ligand binding on the energy landscape of acyl-coenzyme A (CoA)-binding protein (ACBP). ACBP is a topologically simple and highly conserved four-α-helix bundle protein that acts as an intracellular transporter and buffer for fatty-acyl-CoA and is active in membrane assembly. We have previously described the behavior of ACBP under tension, revealing a highly extended transition state (TS) located almost halfway between the unfolded and native states. Here, we performed force-ramp and force-jump experiments, in combination with advanced statistical analysis, to show that octanoyl-CoA binding increases the activation free energy for the unfolding reaction of ACBP without affecting the position of the transition state along the reaction coordinate. It follows that ligand binding enhances the mechanical resistance and thermodynamic stability of the protein, without changing its mechanical compliance. Steered molecular dynamics simulations allowed us to rationalize the results in terms of key interactions that octanoyl-CoA establishes with the four α-helices of ACBP and showed that the unfolding pathway is marginally affected by the ligand. The results show that ligand-induced mechanical stabilization effects can be complex and may prove useful for the rational design of stabilizing ligands.
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Affiliation(s)
- Punam Sonar
- Physik-Department E22, Technische Universität München, Garching Germany
| | - Luca Bellucci
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, Italy
| | - Alessandro Mossa
- INFN Firenze, Sesto Fiorentino, Italy; Istituto Statale di Istruzione Superiore "Leonardo da Vinci", Firenze, Italy.
| | - Pétur O Heidarsson
- Department of Biochemistry, Science Institute, University of Iceland, Reykjavík, Iceland.
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen N, Denmark.
| | - Ciro Cecconi
- Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, Modena, Italy; Center S3, CNR Institute Nanoscience, Modena, Italy.
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30
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The mechanisms of action of chromatin remodelers and implications in development and disease. Biochem Pharmacol 2020; 180:114200. [DOI: 10.1016/j.bcp.2020.114200] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/09/2020] [Accepted: 08/12/2020] [Indexed: 02/06/2023]
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31
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Jain N, Tamborrini D, Evans B, Chaudhry S, Wilkins BJ, Neumann H. Interaction of RSC Chromatin Remodeling Complex with Nucleosomes Is Modulated by H3 K14 Acetylation and H2B SUMOylation In Vivo. iScience 2020; 23:101292. [PMID: 32623337 PMCID: PMC7334588 DOI: 10.1016/j.isci.2020.101292] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 05/27/2020] [Accepted: 06/15/2020] [Indexed: 01/04/2023] Open
Abstract
Chromatin remodeling complexes are multi-subunit nucleosome translocases that reorganize chromatin in the context of DNA replication, repair, and transcription. To understand how these complexes find their target sites on chromatin, we use genetically encoded photo-cross-linker amino acids to map the footprint of Sth1, the catalytic subunit of the RSC complex, on nucleosomes in living yeast. We find that H3 K14 acetylation induces the interaction of the Sth1 bromodomain with the H3 tail and mediates the interaction of RSC with neighboring nucleosomes rather than recruiting it to chromatin. RSC preferentially resides on H2B SUMOylated nucleosomes in vivo and shows a moderately enhanced affinity due to this modification in vitro. Furthermore, RSC is not ejected from chromatin in mitosis, but changes its mode of nucleosome binding. Our in vivo analyses show that RSC recruitment to specific chromatin targets involves multiple histone modifications likely in combination with histone variants and transcription factors.
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Affiliation(s)
- Neha Jain
- Department of Structural Biochemistry, Max-Planck-Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Davide Tamborrini
- Department of Structural Biochemistry, Max-Planck-Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Brian Evans
- Department of Chemistry and Biochemistry, Manhattan College, 4513 Manhattan College Parkway, Bronx, NY 10471, USA
| | - Shereen Chaudhry
- Department of Chemistry and Biochemistry, Manhattan College, 4513 Manhattan College Parkway, Bronx, NY 10471, USA
| | - Bryan J Wilkins
- Department of Chemistry and Biochemistry, Manhattan College, 4513 Manhattan College Parkway, Bronx, NY 10471, USA.
| | - Heinz Neumann
- Department of Structural Biochemistry, Max-Planck-Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany; Department of Chemical Engineering and Biotechnology, University of Applied Sciences Darmstadt, Stephanstrasse 7, 64295 Darmstadt, Germany.
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32
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Crickard JB, Moevus CJ, Kwon Y, Sung P, Greene EC. Rad54 Drives ATP Hydrolysis-Dependent DNA Sequence Alignment during Homologous Recombination. Cell 2020; 181:1380-1394.e18. [PMID: 32502392 DOI: 10.1016/j.cell.2020.04.056] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/07/2020] [Accepted: 04/29/2020] [Indexed: 12/30/2022]
Abstract
Homologous recombination (HR) helps maintain genome integrity, and HR defects give rise to disease, especially cancer. During HR, damaged DNA must be aligned with an undamaged template through a process referred to as the homology search. Despite decades of study, key aspects of this search remain undefined. Here, we use single-molecule imaging to demonstrate that Rad54, a conserved Snf2-like protein found in all eukaryotes, switches the search from the diffusion-based pathways characteristic of the basal HR machinery to an active process in which DNA sequences are aligned via an ATP-dependent molecular motor-driven mechanism. We further demonstrate that Rad54 disrupts the donor template strands, enabling the search to take place within a migrating DNA bubble-like structure that is bound by replication protein A (RPA). Our results reveal that Rad54, working together with RPA, fundamentally alters how DNA sequences are aligned during HR.
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Affiliation(s)
- J Brooks Crickard
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Corentin J Moevus
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Youngho Kwon
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Eric C Greene
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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SMARCA4-deficient Thoracic Sarcomas: Clinicopathologic Study of 30 Cases With an Emphasis on Their Nosology and Differential Diagnoses. Am J Surg Pathol 2020; 43:455-465. [PMID: 30451731 DOI: 10.1097/pas.0000000000001188] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SMARCA4-deficient thoracic sarcoma (SMARCA4-DTS) is a recently described entity with an aggressive clinical course and specific genetic alterations of the BAF chromatin remodeling complex. In the present study, we reviewed the clinical and pathologic features of 30 cases of SMARCA4-DTS, discussed its main differential diagnoses and the challenging diagnostic scenarios that the average pathologist may face. In addition, we tested the specificity of the "SMARCA4-DTS immunohistochemical signature" (co-loss of SMARCA4 and SMARCA2 with overexpression of SOX2) in a large cohort of intrathoracic malignancies. Patients ranged from 28 to 90 years of age (median: 48 y), with a marked male predominance (male:female=9:1) and they were usually smokers. Tumors were generally large compressive masses located in the mediastinum (n=13), pleura (n=5), lung (n=2) or in 2 or more of these topographies (n=10). Treatment strategies were varied, including 1 case treated with EZH2 inhibitors. Median overall survival was 6 months. Histologically, tumors were poorly differentiated frequently showing rhabdoid features. A subset of cases showed a focal myxoid stroma (7%, n=2/30) and rare cases displayed a previously unreported pattern simulating desmoplastic small round cell tumors (7%, n=2/30). Making a diagnosis was challenging when dealing with biopsy material from massively necrotic tumors and in this setting the expression of SOX2, CD34, and SALL4 proved useful. All tested cases displayed concomitant loss of SMARCA4 and SMARCA2 and most tumors expressed epithelial markers (Pan-keratin or EMA) (n=29/30), SOX2 (n=26/27), and CD34 (n=17/27). SMARCB1 expression was retained in all cases (23/23). SALL4 and Claudin-4 were expressed in a subset of cases (n=7/21 and 2/19, respectively). TTF-1 and P63 were focally expressed in 1 case each. P40 and NUT were not expressed (0/23 and 0/20, respectively) The SMARCA4-DTS immunohistochemical signature was both sensitive and specific, with only a subset of small cell carcinoma of the ovary hypercalcemic type showing overlapping phenotypes. Our study confirms and expands the specific features of SMARCA4-DTS, emphasizing the fact that they can be straightforwardly identified by pathologists.
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34
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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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35
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Generation of Remosomes by the SWI/SNF Chromatin Remodeler Family. Sci Rep 2019; 9:14212. [PMID: 31578361 PMCID: PMC6775096 DOI: 10.1038/s41598-019-50572-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 09/04/2019] [Indexed: 12/11/2022] Open
Abstract
Chromatin remodelers are complexes able to both alter histone-DNA interactions and to mobilize nucleosomes. The mechanism of their action and the conformation of remodeled nucleosomes remain a matter of debates. In this work we compared the type and structure of the products of nucleosome remodeling by SWI/SNF and ACF complexes using high-resolution microscopy combined with novel biochemical approaches. We find that SWI/SNF generates a multitude of nucleosome-like metastable particles termed "remosomes". Restriction enzyme accessibility assay, DNase I footprinting and AFM experiments reveal perturbed histone-DNA interactions within these particles. Electron cryo-microscopy shows that remosomes adopt a variety of different structures with variable irregular DNA path, similar to those described upon RSC remodeling. Remosome DNA accessibility to restriction enzymes is also markedly increased. We suggest that the generation of remosomes is a common feature of the SWI/SNF family remodelers. In contrast, the ACF remodeler, belonging to ISWI family, only produces repositioned nucleosomes and no evidence for particles associated with extra DNA, or perturbed DNA paths was found. The remosome generation by the SWI/SNF type of remodelers may represent a novel mechanism involved in processes where nucleosomal DNA accessibility is required, such as DNA repair or transcription regulation.
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36
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Zhurinsky J, Salas-Pino S, Iglesias-Romero AB, Torres-Mendez A, Knapp B, Flor-Parra I, Wang J, Bao K, Jia S, Chang F, Daga RR. Effects of the microtubule nucleator Mto1 on chromosomal movement, DNA repair, and sister chromatid cohesion in fission yeast. Mol Biol Cell 2019; 30:2695-2708. [PMID: 31483748 PMCID: PMC6761766 DOI: 10.1091/mbc.e19-05-0301] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 08/27/2019] [Accepted: 08/30/2019] [Indexed: 11/11/2022] Open
Abstract
Although the function of microtubules (MTs) in chromosomal segregation during mitosis is well characterized, much less is known about the role of MTs in chromosomal functions during interphase. In the fission yeast Schizosaccharomyces pombe, dynamic cytoplasmic MT bundles move chromosomes in an oscillatory manner during interphase via linkages through the nuclear envelope (NE) at the spindle pole body (SPB) and other sites. Mto1 is a cytoplasmic factor that mediates the nucleation and attachment of cytoplasmic MTs to the nucleus. Here, we test the function of these cytoplasmic MTs and Mto1 on DNA repair and recombination during interphase. We find that mto1Δ cells exhibit defects in DNA repair and homologous recombination (HR) and abnormal DNA repair factory dynamics. In these cells, sister chromatids are not properly paired, and binding of Rad21 cohesin subunit along chromosomal arms is reduced. Our findings suggest a model in which cytoplasmic MTs and Mto1 facilitate efficient DNA repair and HR by promoting dynamic chromosomal organization and cohesion in the nucleus.
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Affiliation(s)
- Jacob Zhurinsky
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Silvia Salas-Pino
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Ana B. Iglesias-Romero
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Antonio Torres-Mendez
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Benjamin Knapp
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032
| | - Ignacio Flor-Parra
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Jiyong Wang
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143
| | - Kehan Bao
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143
| | - Songtao Jia
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143
| | - Fred Chang
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032
| | - Rafael R. Daga
- Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville 41013, Spain
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37
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Lee J, Crickard JB, Reese JC, Lee TH. Single-molecule FRET method to investigate the dynamics of transcription elongation through the nucleosome by RNA polymerase II. Methods 2019; 159-160:51-58. [PMID: 30660864 PMCID: PMC6589119 DOI: 10.1016/j.ymeth.2019.01.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 01/07/2019] [Accepted: 01/14/2019] [Indexed: 12/27/2022] Open
Abstract
Transcription elongation through the nucleosome is a precisely coordinated activity to ensure timely production of RNA and accurate regulation of co-transcriptional histone modifications. Nucleosomes actively participate in transcription regulation at various levels and impose physical barriers to RNA polymerase II (RNAPII) during transcription elongation. Despite its high significance, the detailed dynamics of how RNAPII translocates along nucleosomal DNA during transcription elongation and how the nucleosome structure dynamically conforms to the changes necessary for RNAPII progression remain poorly understood. Transcription elongation through the nucleosome is a complex process and investigating the changes of the nucleosome structure during this process by ensemble measurements is daunting. This is because it is nearly impossible to synchronize elongation complexes within a nucleosome or a sub-nucleosome to a designated location at a high enough efficiency for desired sample homogeneity. Here we review our recently developed single-molecule FRET experimental system and method that has fulfilled this deficiency. With our method, one can follow the changes in the structure of individual nucleosomes during transcription elongation. We demonstrated that this method enables the detailed measurements of the kinetics of transcription elongation through the nucleosome and its regulation by a transcription factor, which can be easily extended to investigations of the roles of environmental variables and histone post-translational modifications in regulating transcription elongation.
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Affiliation(s)
- Jaehyoun Lee
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
| | - J Brooks Crickard
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States
| | - Joseph C Reese
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States
| | - Tae-Hee Lee
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States.
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38
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Direct observation of coordinated DNA movements on the nucleosome during chromatin remodelling. Nat Commun 2019; 10:1720. [PMID: 30979890 PMCID: PMC6461674 DOI: 10.1038/s41467-019-09657-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/20/2019] [Indexed: 11/11/2022] Open
Abstract
ATP-dependent chromatin remodelling enzymes (remodellers) regulate DNA accessibility in eukaryotic genomes. Many remodellers reposition (slide) nucleosomes, however, how DNA is propagated around the histone octamer during this process is unclear. Here we examine the real-time coordination of remodeller-induced DNA movements on both sides of the nucleosome using three-colour single-molecule FRET. During sliding by Chd1 and SNF2h remodellers, DNA is shifted discontinuously, with movement of entry-side DNA preceding that of exit-side DNA. The temporal delay between these movements implies a single rate-limiting step dependent on ATP binding and transient absorption or buffering of at least one base pair. High-resolution cross-linking experiments show that sliding can be achieved by buffering as few as 3 bp between entry and exit sides of the nucleosome. We propose that DNA buffering ensures nucleosome stability during ATP-dependent remodelling, and provides a means for communication between remodellers acting on opposite sides of the nucleosome. Chromatin remodelling enzymes (remodellers) regulate DNA accessibility of eukaryotic genomes, which rely in large part on an ability to reposition nucleosomes. Here the authors use three-colour single-molecule FRET to simultaneously monitor remodeller-induced DNA movements on both sides of the nucleosome in real-time.
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39
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Kane AE, Sinclair DA. Epigenetic changes during aging and their reprogramming potential. Crit Rev Biochem Mol Biol 2019; 54:61-83. [PMID: 30822165 PMCID: PMC6424622 DOI: 10.1080/10409238.2019.1570075] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 01/09/2019] [Accepted: 01/11/2019] [Indexed: 02/07/2023]
Abstract
The aging process results in significant epigenetic changes at all levels of chromatin and DNA organization. These include reduced global heterochromatin, nucleosome remodeling and loss, changes in histone marks, global DNA hypomethylation with CpG island hypermethylation, and the relocalization of chromatin modifying factors. Exactly how and why these changes occur is not fully understood, but evidence that these epigenetic changes affect longevity and may cause aging, is growing. Excitingly, new studies show that age-related epigenetic changes can be reversed with interventions such as cyclic expression of the Yamanaka reprogramming factors. This review presents a summary of epigenetic changes that occur in aging, highlights studies indicating that epigenetic changes may contribute to the aging process and outlines the current state of research into interventions to reprogram age-related epigenetic changes.
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Affiliation(s)
- Alice E. Kane
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Charles Perkins Centre, The University of Sydney, Sydney, Australia
| | - David A. Sinclair
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Pharmacology, The University of New South Wales, Sydney, Australia
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40
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Choudhary D, Mossa A, Jadhav M, Cecconi C. Bio-Molecular Applications of Recent Developments in Optical Tweezers. Biomolecules 2019; 9:E23. [PMID: 30641944 PMCID: PMC6359149 DOI: 10.3390/biom9010023] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/02/2019] [Accepted: 01/02/2019] [Indexed: 12/17/2022] Open
Abstract
In the past three decades, the ability to optically manipulate biomolecules has spurred a new era of medical and biophysical research. Optical tweezers (OT) have enabled experimenters to trap, sort, and probe cells, as well as discern the structural dynamics of proteins and nucleic acids at single molecule level. The steady improvement in OT's resolving power has progressively pushed the envelope of their applications; there are, however, some inherent limitations that are prompting researchers to look for alternatives to the conventional techniques. To begin with, OT are restricted by their one-dimensional approach, which makes it difficult to conjure an exhaustive three-dimensional picture of biological systems. The high-intensity trapping laser can damage biological samples, a fact that restricts the feasibility of in vivo applications. Finally, direct manipulation of biological matter at nanometer scale remains a significant challenge for conventional OT. A significant amount of literature has been dedicated in the last 10 years to address the aforementioned shortcomings. Innovations in laser technology and advances in various other spheres of applied physics have been capitalized upon to evolve the next generation OT systems. In this review, we elucidate a few of these developments, with particular focus on their biological applications. The manipulation of nanoscopic objects has been achieved by means of plasmonic optical tweezers (POT), which utilize localized surface plasmons to generate optical traps with enhanced trapping potential, and photonic crystal optical tweezers (PhC OT), which attain the same goal by employing different photonic crystal geometries. Femtosecond optical tweezers (fs OT), constructed by replacing the continuous wave (cw) laser source with a femtosecond laser, promise to greatly reduce the damage to living samples. Finally, one way to transcend the one-dimensional nature of the data gained by OT is to couple them to the other large family of single molecule tools, i.e., fluorescence-based imaging techniques. We discuss the distinct advantages of the aforementioned techniques as well as the alternative experimental perspective they provide in comparison to conventional OT.
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Affiliation(s)
- Dhawal Choudhary
- Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, 41125 Modena, Italy.
- Center S3, CNR Institute Nanoscience, Via Campi 213/A, 41125 Modena, Italy.
| | - Alessandro Mossa
- Istituto Statale di Istruzione Superiore "Leonardo da Vinci", Via del Terzolle 91, 50127 Firenze, Italy.
- Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, Via Giovanni Sansone 1, 50019 Sesto Fiorentino, Italy.
| | - Milind Jadhav
- Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, 41125 Modena, Italy.
| | - Ciro Cecconi
- Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, 41125 Modena, Italy.
- Center S3, CNR Institute Nanoscience, Via Campi 213/A, 41125 Modena, Italy.
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41
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Ma L, Jiao J, Zhang Y. Single-Molecule Optical Tweezers Study of Regulated SNARE Assembly. Methods Mol Biol 2019; 1860:95-114. [PMID: 30317500 DOI: 10.1007/978-1-4939-8760-3_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Intracellular membrane fusion mediates material and information exchange among different cells or cellular compartments with high accuracy and spatiotemporal resolution. Fusion is driven by ordered folding and assembly of soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (SNAP) receptors (SNAREs) and regulated by many other proteins. Understanding regulated SNARE assembly is key to dissecting mechanisms and physiologies of various fusion processes and their associated diseases. Yet, it remains challenging to study regulated SNARE assembly using traditional ensemble-based experimental approaches. Here, we describe our new method to measure the energy and kinetics of neuronal SNARE assembly in the presence of α-SNAP, using a single-molecule manipulation approach based on high-resolution optical tweezers. Detailed experimental protocols and methods of data analysis are shown. This approach can be widely applied to elucidate the effects of regulatory proteins on SNARE assembly and membrane fusion.
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Affiliation(s)
- Lu Ma
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Junyi Jiao
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.,Integrated Graduate Program in Physical and Engineering Biology, New Haven, CT, USA
| | - Yongli Zhang
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.
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42
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Hsu KW, Chow SY, Su BY, Lu YH, Chen CJ, Chen WL, Cheng MY, Fan HF. The synergy between RSC, Nap1 and adjacent nucleosome in nucleosome remodeling. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1862:129-140. [PMID: 30593928 DOI: 10.1016/j.bbagrm.2018.11.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/23/2018] [Accepted: 11/30/2018] [Indexed: 12/29/2022]
Abstract
Eukaryotes have evolved a specific strategy to package DNA. The nucleosome is a 147-base-pair DNA segment wrapped around histone core proteins that plays important roles regulating DNA-dependent biosynthesis and gene expression. Chromatin remodeling complexes (RSC, Remodel the Structure of Chromatin) hydrolyze ATP to perturb DNA-histone contacts, leading to nucleosome sliding and ejection. Here, we utilized tethered particle motion (TPM) experiments to investigate the mechanism of RSC-mediated nucleosome remodeling in detail. We observed ATP-dependent RSC-mediated DNA looping and nucleosome ejection along individual mononucleosomes and dinucleosomes. We found that nucleosome assembly protein 1 (Nap1) enhanced RSC-mediated nucleosome ejection in a two-step disassembly manner from dinucleosomes but not from mononucleosomes. Based on this work, we provide an entire reaction scheme for the RSC-mediated nucleosome remodeling process that includes DNA looping, nucleosome ejection, the influence of adjacent nucleosomes, and the coordinated action between Nap1 and RSC.
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Affiliation(s)
- Kuan-Wei Hsu
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taiwan
| | - Sih-Yao Chow
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taiwan
| | - Bo-Yu Su
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taiwan
| | - Yi-Han Lu
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taiwan
| | - Cyuan-Ji Chen
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taiwan
| | - Wen-Ling Chen
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taiwan
| | - Ming-Yuan Cheng
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taiwan
| | - Hsiu-Fang Fan
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taiwan.
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43
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Brandani GB, Takada S. Chromatin remodelers couple inchworm motion with twist-defect formation to slide nucleosomal DNA. PLoS Comput Biol 2018; 14:e1006512. [PMID: 30395604 PMCID: PMC6237416 DOI: 10.1371/journal.pcbi.1006512] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 11/15/2018] [Accepted: 09/13/2018] [Indexed: 01/25/2023] Open
Abstract
ATP-dependent chromatin remodelers are molecular machines that control genome organization by repositioning, ejecting, or editing nucleosomes, activities that confer them essential regulatory roles on gene expression and DNA replication. Here, we investigate the molecular mechanism of active nucleosome sliding by means of molecular dynamics simulations of the Snf2 remodeler translocase in complex with a nucleosome. During its inchworm motion driven by ATP consumption, the translocase overwrites the original nucleosome energy landscape via steric and electrostatic interactions to induce sliding of nucleosomal DNA unidirectionally. The sliding is initiated at the remodeler binding location via the generation of a pair of twist defects, which then spontaneously propagate to complete sliding throughout the entire nucleosome. We also reveal how remodeler mutations and DNA sequence control active nucleosome repositioning, explaining several past experimental observations. These results offer a detailed mechanistic picture of remodeling important for the complete understanding of these key biological processes. Nucleosomes are the protein-DNA complexes underlying Eukaryotic genome organization, and serve as regulators of gene expression by occluding DNA to other proteins. This regulation requires the precise positioning of nucleosomes along DNA. Chromatin remodelers are the molecular machines that consume ATP to slide nucleosome at their correct locations, but the mechanisms of remodeling are still unclear. Based on the static structural information of a remodeler bound on nucleosome, we performed molecular dynamics computer simulations revealing the details of how remodelers slide nucleosomal DNA: the inchworm-like motion of remodelers create small DNA deformations called twist defects, which then spontaneously propagate throughout the nucleosome to induce sliding. These simulations explain several past experimental findings and are important for our understanding of genome organization.
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Affiliation(s)
- Giovanni B. Brandani
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
- * E-mail:
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44
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Dynamics of Chromatin Fibers: Comparison of Monte Carlo Simulations with Force Spectroscopy. Biophys J 2018; 115:1644-1655. [PMID: 30236784 PMCID: PMC6225046 DOI: 10.1016/j.bpj.2018.06.032] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 06/15/2018] [Accepted: 06/19/2018] [Indexed: 12/17/2022] Open
Abstract
To elucidate conformational dynamics of chromatin fibers, we compared available force-spectroscopy measurements with extensive Monte Carlo simulations of nucleosome arrays under external force. Our coarse-grained model of chromatin includes phenomenological energy terms for the DNA-histone adhesion and the internucleosome stacking interactions. We found that the Monte Carlo fiber ensembles simulated with increasing degrees of DNA unwrapping and the stacking energy 8 kT can account for the intricate force-extension response observed experimentally. Our analysis shows that at low external forces (F < 3.0 picoNewtons), the DNA ends in nucleosomes breathe by ∼10 bp. Importantly, under these conditions, the fiber is highly dynamic, exhibiting continuous unstacking-restacking transitions, allowing accessibility of transcription factors to DNA, while maintaining a relatively compact conformation. Of note, changing the stacking interaction by a few kT, an in silico way to mimic histone modifications, is sufficient to transform an open chromatin state into a compact fiber. The fibers are mostly two-start zigzag folds with rare occurrences of three- to five-start morphologies. The internucleosome stacking is lost during the linear response regime. At the higher forces exceeding 4 picoNewtons, the nucleosome unwrapping becomes stochastic and asymmetric, with one DNA arm opened by ∼55 bp and the other arm only by ∼10 bp. Importantly, this asymmetric unwrapping occurs for any kind of sequence, including the symmetric ones. Our analysis brings new, to our knowledge, insights in dynamics of chromatin modulated by histone epigenetic modifications and molecular motors such as RNA polymerase.
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45
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Sundaramoorthy R, Hughes AL, El-Mkami H, Norman DG, Ferreira H, Owen-Hughes T. Structure of the chromatin remodelling enzyme Chd1 bound to a ubiquitinylated nucleosome. eLife 2018; 7:35720. [PMID: 30079888 PMCID: PMC6118821 DOI: 10.7554/elife.35720] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 07/24/2018] [Indexed: 12/23/2022] Open
Abstract
ATP-dependent chromatin remodelling proteins represent a diverse family of proteins that share ATPase domains that are adapted to regulate protein-DNA interactions. Here, we present structures of the Saccharomyces cerevisiae Chd1 protein engaged with nucleosomes in the presence of the transition state mimic ADP-beryllium fluoride. The path of DNA strands through the ATPase domains indicates the presence of contacts conserved with single strand translocases and additional contacts with both strands that are unique to Snf2 related proteins. The structure provides connectivity between rearrangement of ATPase lobes to a closed, nucleotide bound state and the sensing of linker DNA. Two turns of linker DNA are prised off the surface of the histone octamer as a result of Chd1 binding, and both the histone H3 tail and ubiquitin conjugated to lysine 120 are re-orientated towards the unravelled DNA. This indicates how changes to nucleosome structure can alter the way in which histone epitopes are presented.
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Affiliation(s)
| | - Amanda L Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Hassane El-Mkami
- School of Physics and Astronomy, University of St Andrews, St Andrews, United Kingdom
| | - David G Norman
- Nucleic Acids Structure Research Group, University of Dundee, Dundee, United Kingdom
| | - Helder Ferreira
- School of Biology, University of St Andrews, St Andrews, United Kingdom
| | - Tom Owen-Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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46
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Morgan AM, LeGresley SE, Briggs K, Al-Ani G, Fischer CJ. Effects of nucleosome stability on remodeler-catalyzed repositioning. Phys Rev E 2018; 97:032422. [PMID: 29776169 DOI: 10.1103/physreve.97.032422] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Indexed: 06/08/2023]
Abstract
Chromatin remodelers are molecular motors that play essential roles in the regulation of nucleosome positioning and chromatin accessibility. These machines couple the energy obtained from the binding and hydrolysis of ATP to the mechanical work of manipulating chromatin structure through processes that are not completely understood. Here we present a quantitative analysis of nucleosome repositioning by the imitation switch (ISWI) chromatin remodeler and demonstrate that nucleosome stability significantly impacts the observed activity. We show how DNA damage induced changes in the affinity of DNA wrapping within the nucleosome can affect ISWI repositioning activity and demonstrate how assay-dependent limitations can bias studies of nucleosome repositioning. Together, these results also suggest that some of the diversity seen in chromatin remodeler activity can be attributed to the variations in the thermodynamics of interactions between the remodeler, the histones, and the DNA, rather than reflect inherent properties of the remodeler itself.
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Affiliation(s)
- Aaron M Morgan
- Department of Physics and Astronomy, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, USA
| | - Sarah E LeGresley
- Department of Physics and Astronomy, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, USA
| | - Koan Briggs
- Department of Physics and Astronomy, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, USA
| | - Gada Al-Ani
- Department of Physics and Astronomy, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, USA
| | - Christopher J Fischer
- Department of Physics and Astronomy, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, USA
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47
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Sinha KK, Gross JD, Narlikar GJ. Distortion of histone octamer core promotes nucleosome mobilization by a chromatin remodeler. Science 2017; 355:355/6322/eaaa3761. [PMID: 28104838 DOI: 10.1126/science.aaa3761] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 09/26/2016] [Accepted: 12/05/2016] [Indexed: 12/25/2022]
Abstract
Adenosine 5'-triphosphate (ATP)-dependent chromatin remodeling enzymes play essential biological roles by mobilizing nucleosomal DNA. Yet, how DNA is mobilized despite the steric constraints placed by the histone octamer remains unknown. Using methyl transverse relaxation-optimized nuclear magnetic resonance spectroscopy on a 450-kilodalton complex, we show that the chromatin remodeler, SNF2h, distorts the histone octamer. Binding of SNF2h in an activated ATP state changes the dynamics of buried histone residues. Preventing octamer distortion by site-specific disulfide linkages inhibits nucleosome sliding by SNF2h while promoting octamer eviction by the SWI-SNF complex, RSC. Our findings indicate that the histone core of a nucleosome is more plastic than previously imagined and that octamer deformation plays different roles based on the type of chromatin remodeler. Octamer plasticity may contribute to chromatin regulation beyond ATP-dependent remodeling.
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Affiliation(s)
- Kalyan K Sinha
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
| | - John D Gross
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA.
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA.
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48
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Clapier CR, Iwasa J, Cairns BR, Peterson CL. Mechanisms of action and regulation of ATP-dependent chromatin-remodelling complexes. Nat Rev Mol Cell Biol 2017; 18:407-422. [PMID: 28512350 DOI: 10.1038/nrm.2017.26] [Citation(s) in RCA: 703] [Impact Index Per Article: 100.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cells utilize diverse ATP-dependent nucleosome-remodelling complexes to carry out histone sliding, ejection or the incorporation of histone variants, suggesting that different mechanisms of action are used by the various chromatin-remodelling complex subfamilies. However, all chromatin-remodelling complex subfamilies contain an ATPase-translocase 'motor' that translocates DNA from a common location within the nucleosome. In this Review, we discuss (and illustrate with animations) an alternative, unifying mechanism of chromatin remodelling, which is based on the regulation of DNA translocation. We propose the 'hourglass' model of remodeller function, in which each remodeller subfamily utilizes diverse specialized proteins and protein domains to assist in nucleosome targeting or to differentially detect nucleosome epitopes. These modules converge to regulate a common DNA translocation mechanism, to inform the conserved ATPase 'motor' on whether and how to apply DNA translocation, which together achieve the various outcomes of chromatin remodelling: nucleosome assembly, chromatin access and nucleosome editing.
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Affiliation(s)
- Cedric R Clapier
- Howard Hughes Medical Institute and Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA
| | - Janet Iwasa
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA
| | - Bradley R Cairns
- Howard Hughes Medical Institute and Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA
| | - Craig L Peterson
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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49
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Dunlap JC, Loros JJ. Making Time: Conservation of Biological Clocks from Fungi to Animals. Microbiol Spectr 2017; 5:10.1128/microbiolspec.FUNK-0039-2016. [PMID: 28527179 PMCID: PMC5446046 DOI: 10.1128/microbiolspec.funk-0039-2016] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Indexed: 01/03/2023] Open
Abstract
The capacity for biological timekeeping arose at least three times through evolution, in prokaryotic cyanobacteria, in cells that evolved into higher plants, and within the group of organisms that eventually became the fungi and the animals. Neurospora is a tractable model system for understanding the molecular bases of circadian rhythms in the last of these groups, and is perhaps the most intensively studied circadian cell type. Rhythmic processes described in fungi include growth rate, stress responses, developmental capacity, and sporulation, as well as much of metabolism; fungi use clocks to anticipate daily environmental changes. A negative feedback loop comprises the core of the circadian system in fungi and animals. In Neurospora, the best studied fungal model, it is driven by two transcription factors, WC-1 and WC-2, that form the White Collar Complex (WCC). WCC elicits expression of the frq gene. FRQ complexes with other proteins, physically interacts with the WCC, and reduces its activity; the kinetics of these processes is strongly influenced by progressive phosphorylation of FRQ. When FRQ becomes sufficiently phosphorylated that it loses the ability to influence WCC activity, the circadian cycle starts again. Environmental cycles of light and temperature influence frq and FRQ expression and thereby reset the internal circadian clocks. The molecular basis of circadian output is also becoming understood. Taken together, molecular explanations are emerging for all the canonical circadian properties, providing a molecular and regulatory framework that may be extended to many members of the fungal and animal kingdoms, including humans.
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Affiliation(s)
- Jay C Dunlap
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Jennifer J Loros
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
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50
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Sundaramoorthy R, Hughes AL, Singh V, Wiechens N, Ryan DP, El-Mkami H, Petoukhov M, Svergun DI, Treutlein B, Quack S, Fischer M, Michaelis J, Böttcher B, Norman DG, Owen-Hughes T. Structural reorganization of the chromatin remodeling enzyme Chd1 upon engagement with nucleosomes. eLife 2017; 6. [PMID: 28332978 PMCID: PMC5391205 DOI: 10.7554/elife.22510] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 03/15/2017] [Indexed: 12/11/2022] Open
Abstract
The yeast Chd1 protein acts to position nucleosomes across genomes. Here, we model the structure of the Chd1 protein in solution and when bound to nucleosomes. In the apo state, the DNA-binding domain contacts the edge of the nucleosome while in the presence of the non-hydrolyzable ATP analog, ADP-beryllium fluoride, we observe additional interactions between the ATPase domain and the adjacent DNA gyre 1.5 helical turns from the dyad axis of symmetry. Binding in this conformation involves unravelling the outer turn of nucleosomal DNA and requires substantial reorientation of the DNA-binding domain with respect to the ATPase domains. The orientation of the DNA-binding domain is mediated by sequences in the N-terminus and mutations to this part of the protein have positive and negative effects on Chd1 activity. These observations indicate that the unfavorable alignment of C-terminal DNA-binding region in solution contributes to an auto-inhibited state. DOI:http://dx.doi.org/10.7554/eLife.22510.001
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Affiliation(s)
| | - Amanda L Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Vijender Singh
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Nicola Wiechens
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Daniel P Ryan
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Hassane El-Mkami
- School of Physics and Astronomy, University of St Andrews, St Andrews, United Kingdom
| | - Maxim Petoukhov
- Hamburg Outstation, European Molecular Biology Laboratory, Hamburg, Germany
| | - Dmitri I Svergun
- Hamburg Outstation, European Molecular Biology Laboratory, Hamburg, Germany
| | - Barbara Treutlein
- Institute for Biophysics, Faculty of Natural Sciences, Ulm University, Ulm, Germany
| | - Salina Quack
- Institute for Biophysics, Faculty of Natural Sciences, Ulm University, Ulm, Germany
| | - Monika Fischer
- Institute for Biophysics, Faculty of Natural Sciences, Ulm University, Ulm, Germany
| | - Jens Michaelis
- Institute for Biophysics, Faculty of Natural Sciences, Ulm University, Ulm, Germany
| | - Bettina Böttcher
- Lehrstuhl für Biochemie, Rudolf-Virchow Zentrum, Universitat Würzburg, Würzburg, Germany
| | - David G Norman
- Nucleic Acids Structure Research Group, University of Dundee, Dundee, United Kingdom
| | - Tom Owen-Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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