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Ortabozkoyun H, Huang PY, Gonzalez-Buendia E, Cho H, Kim SY, Tsirigos A, Mazzoni EO, Reinberg D. Members of an array of zinc-finger proteins specify distinct Hox chromatin boundaries. Mol Cell 2024:S1097-2765(24)00661-0. [PMID: 39173638 DOI: 10.1016/j.molcel.2024.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 05/06/2024] [Accepted: 08/05/2024] [Indexed: 08/24/2024]
Abstract
Partitioning of repressive from actively transcribed chromatin in mammalian cells fosters cell-type-specific gene expression patterns. While this partitioning is reconstructed during differentiation, the chromatin occupancy of the key insulator, CCCTC-binding factor (CTCF), is unchanged at the developmentally important Hox clusters. Thus, dynamic changes in chromatin boundaries must entail other activities. Given its requirement for chromatin loop formation, we examined cohesin-based chromatin occupancy without known insulators, CTCF and Myc-associated zinc-finger protein (MAZ), and identified a family of zinc-finger proteins (ZNFs), some of which exhibit tissue-specific expression. Two such ZNFs foster chromatin boundaries at the Hox clusters that are distinct from each other and from MAZ. PATZ1 was critical to the thoracolumbar boundary in differentiating motor neurons and mouse skeleton, while ZNF263 contributed to cervicothoracic boundaries. We propose that these insulating activities act with cohesin, alone or combinatorially, with or without CTCF, to implement precise positional identity and cell fate during development.
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Affiliation(s)
- Havva Ortabozkoyun
- Howard Hughes Medical Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA.
| | - Pin-Yao Huang
- Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA
| | - Edgar Gonzalez-Buendia
- Howard Hughes Medical Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA
| | - Hyein Cho
- Department of Pathology, NYU Langone Health, New York, NY 10016, USA; Applied Bioinformatics Laboratories, NYU Langone Health, New York, NY 10016, USA; Department of Medicine, Division of Precision Medicine, NYU Langone Health, New York, NY 10016, USA
| | - Sang Y Kim
- Department of Pathology, NYU Langone Health, New York, NY 10016, USA
| | - Aristotelis Tsirigos
- Department of Pathology, NYU Langone Health, New York, NY 10016, USA; Applied Bioinformatics Laboratories, NYU Langone Health, New York, NY 10016, USA; Institute for Computational Medicine, NYU Langone Health, New York, NY 10016, USA
| | - Esteban O Mazzoni
- Department of Cell Biology, NYU Langone Health, New York, NY 10016, USA
| | - Danny Reinberg
- Howard Hughes Medical Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA.
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2
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Ortabozkoyun H, Huang PY, Gonzalez-Buendia E, Cho H, Kim SY, Tsirigos A, Mazzoni EO, Reinberg D. Members of an array of zinc finger proteins specify distinct Hox chromatin boundaries. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.25.538167. [PMID: 37162865 PMCID: PMC10168243 DOI: 10.1101/2023.04.25.538167] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Partitioning of repressive from actively transcribed chromatin in mammalian cells fosters cell-type specific gene expression patterns. While this partitioning is reconstructed during differentiation, the chromatin occupancy of the key insulator, CTCF, is unchanged at the developmentally important Hox clusters. Thus, dynamic changes in chromatin boundaries must entail other activities. Given its requirement for chromatin loop formation, we examined cohesin-based chromatin occupancy without known insulators, CTCF and MAZ, and identified a family of zinc finger proteins (ZNFs), some of which exhibit tissue-specific expression. Two such ZNFs foster chromatin boundaries at the Hox clusters that are distinct from each other and from MAZ. PATZ1 was critical to the thoracolumbar boundary in differentiating motor neurons and mouse skeleton, while ZNF263 contributed to cervicothoracic boundaries. We propose that these insulating activities act with cohesin, alone or combinatorially, with or without CTCF, to implement precise positional identity and cell fate during development.
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3
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Sen D, Maniyadath B, Chowdhury S, Kaur A, Khatri S, Chakraborty A, Mehendale N, Nadagouda S, Sandra U, Kamat SS, Kolthur-Seetharam U. Metabolic regulation of CTCF expression and chromatin association dictates starvation response in mice and flies. iScience 2023; 26:107128. [PMID: 37416476 PMCID: PMC10320512 DOI: 10.1016/j.isci.2023.107128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 05/16/2023] [Accepted: 06/10/2023] [Indexed: 07/08/2023] Open
Abstract
Coordinated temporal control of gene expression is essential for physiological homeostasis, especially during metabolic transitions. However, the interplay between chromatin architectural proteins and metabolism in regulating transcription is less understood. Here, we demonstrate a conserved bidirectional interplay between CTCF (CCCTC-binding factor) expression/function and metabolic inputs during feed-fast cycles. Our results indicate that its loci-specific functional diversity is associated with physiological plasticity in mouse hepatocytes. CTCF differential expression and long non-coding RNA-Jpx mediated changes in chromatin occupancy, unraveled its paradoxical yet tuneable functions, which are governed by metabolic inputs. We illustrate the key role of CTCF in controlling temporal cascade of transcriptional response, with effects on hepatic mitochondrial energetics and lipidome. Underscoring the evolutionary conservation of CTCF-dependent metabolic homeostasis, CTCF knockdown in flies abrogated starvation resistance. In summary, we demonstrate the interplay between CTCF and metabolic inputs that highlights the coupled plasticity of physiological responses and chromatin function.
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Affiliation(s)
- Devashish Sen
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Babukrishna Maniyadath
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Shreyam Chowdhury
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Arshdeep Kaur
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Subhash Khatri
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Arnab Chakraborty
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra 411008, India
| | - Neelay Mehendale
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra 411008, India
| | - Snigdha Nadagouda
- Tata Institute of Fundamental Research- Hyderabad (TIFR-H), Hyderabad, Telangana 500046, India
| | - U.S. Sandra
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Siddhesh S. Kamat
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra 411008, India
| | - Ullas Kolthur-Seetharam
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
- Tata Institute of Fundamental Research- Hyderabad (TIFR-H), Hyderabad, Telangana 500046, India
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4
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Price E, Fedida LM, Pugacheva EM, Ji YJ, Loukinov D, Lobanenkov VV. An updated catalog of CTCF variants associated with neurodevelopmental disorder phenotypes. Front Mol Neurosci 2023; 16:1185796. [PMID: 37324587 PMCID: PMC10264798 DOI: 10.3389/fnmol.2023.1185796] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/02/2023] [Indexed: 06/17/2023] Open
Abstract
Introduction CTCF-related disorder (CRD) is a neurodevelopmental disorder (NDD) caused by monoallelic pathogenic variants in CTCF. The first CTCF variants in CRD cases were documented in 2013. To date, 76 CTCF variants have been further described in the literature. In recent years, due to the increased application of next-generation sequencing (NGS), growing numbers of CTCF variants are being identified, and multiple genotype-phenotype databases cataloging such variants are emerging. Methods In this study, we aimed to expand the genotypic spectrum of CRD, by cataloging NDD phenotypes associated with reported CTCF variants. Here, we systematically reviewed all known CTCF variants reported in case studies and large-scale exome sequencing cohorts. We also conducted a meta-analysis using public variant data from genotype-phenotype databases to identify additional CTCF variants, which we then curated and annotated. Results From this combined approach, we report an additional 86 CTCF variants associated with NDD phenotypes that have not yet been described in the literature. Furthermore, we describe and explain inconsistencies in the quality of reported variants, which impairs the reuse of data for research of NDDs and other pathologies. Discussion From this integrated analysis, we provide a comprehensive and annotated catalog of all currently known CTCF mutations associated with NDD phenotypes, to aid diagnostic applications, as well as translational and basic research.
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5
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Kahn TG, Savitsky M, Kuong C, Jacquier C, Cavalli G, Chang JM, Schwartz YB. Topological screen identifies hundreds of Cp190- and CTCF-dependent Drosophila chromatin insulator elements. SCIENCE ADVANCES 2023; 9:eade0090. [PMID: 36735780 PMCID: PMC9897668 DOI: 10.1126/sciadv.ade0090] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 01/03/2023] [Indexed: 06/18/2023]
Abstract
Drosophila insulators were the first DNA elements found to regulate gene expression by delimiting chromatin contacts. We still do not know how many of them exist and what impact they have on the Drosophila genome folding. Contrary to vertebrates, there is no evidence that fly insulators block cohesin-mediated chromatin loop extrusion. Therefore, their mechanism of action remains uncertain. To bridge these gaps, we mapped chromatin contacts in Drosophila cells lacking the key insulator proteins CTCF and Cp190. With this approach, we found hundreds of insulator elements. Their study indicates that Drosophila insulators play a minor role in the overall genome folding but affect chromatin contacts locally at many loci. Our observations argue that Cp190 promotes cobinding of other insulator proteins and that the model, where Drosophila insulators block chromatin contacts by forming loops, needs revision. Our insulator catalog provides an important resource to study mechanisms of genome folding.
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Affiliation(s)
- Tatyana G. Kahn
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | | | - Chikuan Kuong
- Department of Computer Science, National Chengchi University, Taipei City, Taiwan
| | | | - Giacomo Cavalli
- Institute of Human Genetics, UMR9002 CNRS, Montpellier, France
| | - Jia-Ming Chang
- Department of Computer Science, National Chengchi University, Taipei City, Taiwan
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6
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Chen S, Rosin LF, Pegoraro G, Moshkovich N, Murphy PJ, Yu G, Lei EP. NURF301 contributes to gypsy chromatin insulator-mediated nuclear organization. Nucleic Acids Res 2022; 50:7906-7924. [PMID: 35819192 PMCID: PMC9371915 DOI: 10.1093/nar/gkac600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/26/2022] [Accepted: 06/29/2022] [Indexed: 11/14/2022] Open
Abstract
Chromatin insulators are DNA-protein complexes that can prevent the spread of repressive chromatin and block communication between enhancers and promoters to regulate gene expression. In Drosophila, the gypsy chromatin insulator complex consists of three core proteins: CP190, Su(Hw), and Mod(mdg4)67.2. These factors concentrate at nuclear foci termed insulator bodies, and changes in insulator body localization have been observed in mutants defective for insulator function. Here, we identified NURF301/E(bx), a nucleosome remodeling factor, as a novel regulator of gypsy insulator body localization through a high-throughput RNAi imaging screen. NURF301 promotes gypsy-dependent insulator barrier activity and physically interacts with gypsy insulator proteins. Using ChIP-seq, we found that NURF301 co-localizes with insulator proteins genome-wide, and NURF301 promotes chromatin association of Su(Hw) and CP190 at gypsy insulator binding sites. These effects correlate with NURF301-dependent nucleosome repositioning. At the same time, CP190 and Su(Hw) both facilitate recruitment of NURF301 to chromatin. Finally, Oligopaint FISH combined with immunofluorescence revealed that NURF301 promotes 3D contact between insulator bodies and gypsy insulator DNA binding sites, and NURF301 is required for proper nuclear positioning of gypsy binding sites. Our data provide new insights into how a nucleosome remodeling factor and insulator proteins cooperatively contribute to nuclear organization.
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Affiliation(s)
- Shue Chen
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Leah F Rosin
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Gianluca Pegoraro
- High-Throughput Imaging Facility (HiTIF), Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Nellie Moshkovich
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Patrick J Murphy
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Guoyun Yu
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Elissa P Lei
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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7
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Cummings CT, Rowley MJ. Implications of Dosage Deficiencies in CTCF and Cohesin on Genome Organization, Gene Expression, and Human Neurodevelopment. Genes (Basel) 2022; 13:583. [PMID: 35456389 PMCID: PMC9030571 DOI: 10.3390/genes13040583] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/14/2022] [Accepted: 03/24/2022] [Indexed: 02/07/2023] Open
Abstract
Properly organizing DNA within the nucleus is critical to ensure normal downstream nuclear functions. CTCF and cohesin act as major architectural proteins, working in concert to generate thousands of high-intensity chromatin loops. Due to their central role in loop formation, a massive research effort has been dedicated to investigating the mechanism by which CTCF and cohesin create these loops. Recent results lead to questioning the direct impact of CTCF loops on gene expression. Additionally, results of controlled depletion experiments in cell lines has indicated that genome architecture may be somewhat resistant to incomplete deficiencies in CTCF or cohesin. However, heterozygous human genetic deficiencies in CTCF and cohesin have illustrated the importance of their dosage in genome architecture, cellular processes, animal behavior, and disease phenotypes. Thus, the importance of considering CTCF or cohesin levels is especially made clear by these heterozygous germline variants that characterize genetic syndromes, which are increasingly recognized in clinical practice. Defined primarily by developmental delay and intellectual disability, the phenotypes of CTCF and cohesin deficiency illustrate the importance of architectural proteins particularly in neurodevelopment. We discuss the distinct roles of CTCF and cohesin in forming chromatin loops, highlight the major role that dosage of each protein plays in the amplitude of observed effects on gene expression, and contrast these results to heterozygous mutation phenotypes in murine models and clinical patients. Insights highlighted by this comparison have implications for future research into these newly emerging genetic syndromes.
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Affiliation(s)
- Christopher T. Cummings
- Munroe-Meyer Institute, Department of Genetic Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA;
- Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - M. Jordan Rowley
- Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
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8
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3D Genome Organization: Causes and Consequences for DNA Damage and Repair. Genes (Basel) 2021; 13:genes13010007. [PMID: 35052348 PMCID: PMC8775012 DOI: 10.3390/genes13010007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/16/2021] [Accepted: 12/18/2021] [Indexed: 01/02/2023] Open
Abstract
The inability to repair damaged DNA severely compromises the integrity of any organism. In eukaryotes, the DNA damage response (DDR) operates within chromatin, a tightly organized DNA–histone complex in a non-random manner within the nucleus. Chromatin thus orchestrates various cellular processes, including repair. Here, we examine the chromatin landscape before, during, and after the DNA damage, focusing on double strand breaks (DSBs). We study how chromatin is modified during the repair process, not only around the damaged region (in cis), but also genome-wide (in trans). Recent evidence has highlighted a complex landscape in which different chromatin parameters (stiffness, compaction, loops) are transiently modified, defining “codes” for each specific stage of the DDR. We illustrate a novel aspect of DDR where chromatin modifications contribute to the movement of DSB-damaged chromatin, as well as undamaged chromatin, ensuring the mobilization of DSBs, their clustering, and their repair processes.
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9
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Kurbidaeva A, Purugganan M. Insulators in Plants: Progress and Open Questions. Genes (Basel) 2021; 12:genes12091422. [PMID: 34573404 PMCID: PMC8470105 DOI: 10.3390/genes12091422] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/08/2021] [Accepted: 09/14/2021] [Indexed: 11/16/2022] Open
Abstract
The genomes of higher eukaryotes are partitioned into topologically associated domains or TADs, and insulators (also known as boundary elements) are the key elements responsible for their formation and maintenance. Insulators were first identified and extensively studied in Drosophila as well as mammalian genomes, and have also been described in yeast and plants. In addition, many insulator proteins are known in Drosophila, and some have been investigated in mammals. However, much less is known about this important class of non-coding DNA elements in plant genomes. In this review, we take a detailed look at known plant insulators across different species and provide an overview of potential determinants of plant insulator functions, including cis-elements and boundary proteins. We also discuss methods previously used in attempts to identify plant insulators, provide a perspective on their importance for research and biotechnology, and discuss areas of potential future research.
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10
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Kyrchanova O, Klimenko N, Postika N, Bonchuk A, Zolotarev N, Maksimenko O, Georgiev P. Drosophila architectural protein CTCF is not essential for fly survival and is able to function independently of CP190. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2021; 1864:194733. [PMID: 34311130 DOI: 10.1016/j.bbagrm.2021.194733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/15/2021] [Accepted: 07/15/2021] [Indexed: 12/20/2022]
Abstract
CTCF is the most likely ancestor of proteins that contain large clusters of C2H2 zinc finger domains (C2H2) and is conserved among most bilateral organisms. In mammals, CTCF functions as the main architectural protein involved in the organization of topology-associated domains (TADs). In vertebrates and Drosophila, CTCF is involved in the regulation of homeotic genes. Previously, it was found that null mutations in the dCTCF gene died as pharate adults, which failed to eclose from their pupal case, or shortly after hatching of adults. Here, we obtained several new null dCTCF mutations and found that the complete inactivation of dCTCF appears is limited mainly to phenotypic manifestations of the Abd-B gene and fertility of adult flies. Many modifiers that are not associated with an independent phenotypic manifestation can significantly enhance the expressivity of the null dCTCF mutations, indicating that other architectural proteins are able to functionally compensate for dCTCF inactivation in Drosophila. We also mapped the 715-735 aa region of dCTCF as being essential for the interaction with the BTB (Broad-Complex, Tramtrack, and Bric a brac) and microtubule-targeting (M) domains of the CP190 protein, which binds to many architectural proteins. However, the mutational analysis showed that the interaction with CP190 was not important for the functional activity of dCTCF in vivo.
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Affiliation(s)
- Olga Kyrchanova
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow 119334, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow 119334, Russia
| | - Natalia Klimenko
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow 119334, Russia
| | - Nikolay Postika
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow 119334, Russia
| | - Artem Bonchuk
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow 119334, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow 119334, Russia
| | - Nikolay Zolotarev
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow 119334, Russia
| | - Oksana Maksimenko
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow 119334, Russia
| | - Pavel Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow 119334, Russia.
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Peterson SC, Samuelson KB, Hanlon SL. Multi-Scale Organization of the Drosophila melanogaster Genome. Genes (Basel) 2021; 12:817. [PMID: 34071789 PMCID: PMC8228293 DOI: 10.3390/genes12060817] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/21/2021] [Accepted: 05/26/2021] [Indexed: 12/16/2022] Open
Abstract
Interphase chromatin, despite its appearance, is a highly organized framework of loops and bends. Chromosomes are folded into topologically associating domains, or TADs, and each chromosome and its homolog occupy a distinct territory within the nucleus. In Drosophila, genome organization is exceptional because homologous chromosome pairing is in both germline and somatic tissues, which promote interhomolog interactions such as transvection that can affect gene expression in trans. In this review, we focus on what is known about genome organization in Drosophila and discuss it from TADs to territory. We start by examining intrachromosomal organization at the sub-chromosome level into TADs, followed by a comprehensive analysis of the known proteins that play a key role in TAD formation and boundary establishment. We then zoom out to examine interhomolog interactions such as pairing and transvection that are abundant in Drosophila but rare in other model systems. Finally, we discuss chromosome territories that form within the nucleus, resulting in a complete picture of the multi-scale organization of the Drosophila genome.
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Affiliation(s)
| | | | - Stacey L. Hanlon
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA; (S.C.P.); (K.B.S.)
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12
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Elmer JL, Hay AD, Kessler NJ, Bertozzi TM, Ainscough EAC, Ferguson-Smith AC. Genomic properties of variably methylated retrotransposons in mouse. Mob DNA 2021; 12:6. [PMID: 33612119 PMCID: PMC7898769 DOI: 10.1186/s13100-021-00235-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 02/02/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Transposable elements (TEs) are enriched in cytosine methylation, preventing their mobility within the genome. We previously identified a genome-wide repertoire of candidate intracisternal A particle (IAP) TEs in mice that exhibit inter-individual variability in this methylation (VM-IAPs) with implications for genome function. RESULTS Here we validate these metastable epialleles and discover a novel class that exhibit tissue specificity (tsVM-IAPs) in addition to those with uniform methylation in all tissues (constitutive- or cVM-IAPs); both types have the potential to regulate genes in cis. Screening for variable methylation at other TEs shows that this phenomenon is largely limited to IAPs, which are amongst the youngest and most active endogenous retroviruses. We identify sequences enriched within cVM-IAPs, but determine that these are not sufficient to confer epigenetic variability. CTCF is enriched at VM-IAPs with binding inversely correlated with DNA methylation. We uncover dynamic physical interactions between cVM-IAPs with low methylation ranges and other genomic loci, suggesting that VM-IAPs have the potential for long-range regulation. CONCLUSION Our findings indicate that a recently evolved interplay between genetic sequence, CTCF binding, and DNA methylation at young TEs can result in inter-individual variability in transcriptional outcomes with implications for phenotypic variation.
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Affiliation(s)
- Jessica L. Elmer
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH UK
| | - Amir D. Hay
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH UK
| | - Noah J. Kessler
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH UK
| | - Tessa M. Bertozzi
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH UK
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13
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Maksimenko OG, Fursenko DV, Belova EV, Georgiev PG. CTCF As an Example of DNA-Binding Transcription Factors Containing Clusters of C2H2-Type Zinc Fingers. Acta Naturae 2021; 13:31-46. [PMID: 33959385 PMCID: PMC8084297 DOI: 10.32607/actanaturae.11206] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/12/2020] [Indexed: 12/11/2022] Open
Abstract
In mammals, most of the boundaries of topologically associating domains and all well-studied insulators are rich in binding sites for the CTCF protein. According to existing experimental data, CTCF is a key factor in the organization of the architecture of mammalian chromosomes. A characteristic feature of the CTCF is that the central part of the protein contains a cluster consisting of eleven domains of C2H2-type zinc fingers, five of which specifically bind to a long DNA sequence conserved in most animals. The class of transcription factors that carry a cluster of C2H2-type zinc fingers consisting of five or more domains (C2H2 proteins) is widely represented in all groups of animals. The functions of most C2H2 proteins still remain unknown. This review presents data on the structure and possible functions of these proteins, using the example of the vertebrate CTCF protein and several well- characterized C2H2 proteins in Drosophila and mammals.
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Affiliation(s)
- O. G. Maksimenko
- Institute of Gene Biology RAS, Moscow, 119334 Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology RAS, Moscow, 119334 Russia
| | | | - E. V. Belova
- Institute of Gene Biology RAS, Moscow, 119334 Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology RAS, Moscow, 119334 Russia
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14
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Tran A, Johnson DA. Mutational analysis identifies functional Rap1, Su(Hw), and CTCF insulator sites in Arabidopsis thaliana. PLANT CELL REPORTS 2020; 39:1743-1753. [PMID: 32959125 DOI: 10.1007/s00299-020-02601-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
Genetic analysis identifies multiple, potential protein binding sites important for insulator function in Arabidopsis thaliana: Rap1 site in UASrpg, Su(Hw) site in UASrpg, and CTCF site in BEAD1c. Three non-plant insulators UASrpg, BEAD1c, and gypsy isolated from Ashbya gossypii, Homo sapiens and Drosophila melanogaster gypsy retrotransposon, respectively, demonstrate insulator function in transgenic Arabidopsis thaliana. Here, the hypothesis that DNA sequences functional in A. thaliana are the same as those in the original host as previously assumed, was tested. Genetic analyses of the cloned fragments in an enhancer blocking assay system was performed through deletions and mutations to identify more precisely which sequences within the cloned fragments function as insulators. Significant loss of insulator activity was observed when the UASrpg Rap1 binding site R2 was mutated but not R1. Cloned fragments containing BEAD1c are effective insulators in our assay system and the previously investigated gypsy insulator is non-functional. Further analyses identified potential Su(Hw) and CTCF sites within UASrpg, of which only the Su(Hw) site was functional. Thus, the activity of non-plant insulators in A. thaliana is context dependent. These results support the hypothesis that insulator function is conserved across kingdoms.
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Affiliation(s)
- Anh Tran
- Biology Department, University of Ottawa, Ottawa, Ontario, Canada.
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15
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Magaña-Acosta M, Valadez-Graham V. Chromatin Remodelers in the 3D Nuclear Compartment. Front Genet 2020; 11:600615. [PMID: 33329746 PMCID: PMC7673392 DOI: 10.3389/fgene.2020.600615] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 10/07/2020] [Indexed: 12/15/2022] Open
Abstract
Chromatin remodeling complexes (CRCs) use ATP hydrolysis to maintain correct expression profiles, chromatin stability, and inherited epigenetic states. More than 20 CRCs have been described to date, which encompass four large families defined by their ATPase subunits. These complexes and their subunits are conserved from yeast to humans through evolution. Their activities depend on their catalytic subunits which through ATP hydrolysis provide the energy necessary to fulfill cellular functions such as gene transcription, DNA repair, and transposon silencing. These activities take place at the first levels of chromatin compaction, and CRCs have been recognized as essential elements of chromatin dynamics. Recent studies have demonstrated an important role for these complexes in the maintenance of higher order chromatin structure. In this review, we present an overview of the organization of the genome within the cell nucleus, the different levels of chromatin compaction, and importance of the architectural proteins, and discuss the role of CRCs and how their functions contribute to the dynamics of the 3D genome organization.
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Affiliation(s)
- Mauro Magaña-Acosta
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Viviana Valadez-Graham
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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16
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Melnikova LS, Georgiev PG, Golovnin AK. The Functions and Mechanisms of Action of Insulators in the Genomes of Higher Eukaryotes. Acta Naturae 2020; 12:15-33. [PMID: 33456975 PMCID: PMC7800606 DOI: 10.32607/actanaturae.11144] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/12/2020] [Indexed: 12/22/2022] Open
Abstract
The mechanisms underlying long-range interactions between chromatin regions and the principles of chromosomal architecture formation are currently under extensive scrutiny. A special class of regulatory elements known as insulators is believed to be involved in the regulation of specific long-range interactions between enhancers and promoters. This review focuses on the insulators of Drosophila and mammals, and it also briefly characterizes the proteins responsible for their functional activity. It was initially believed that the main properties of insulators are blocking of enhancers and the formation of independent transcription domains. We present experimental data proving that the chromatin loops formed by insulators play only an auxiliary role in enhancer blocking. The review also discusses the mechanisms involved in the formation of topologically associating domains and their role in the formation of the chromosomal architecture and regulation of gene transcription.
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Affiliation(s)
- L. S. Melnikova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
| | - P. G. Georgiev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
| | - A. K. Golovnin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
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17
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Hu G, Dong X, Gong S, Song Y, Hutchins AP, Yao H. Systematic screening of CTCF binding partners identifies that BHLHE40 regulates CTCF genome-wide distribution and long-range chromatin interactions. Nucleic Acids Res 2020; 48:9606-9620. [PMID: 32885250 PMCID: PMC7515718 DOI: 10.1093/nar/gkaa705] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 07/27/2020] [Accepted: 08/14/2020] [Indexed: 11/14/2022] Open
Abstract
CTCF plays a pivotal role in mediating chromatin interactions, but it does not do so alone. A number of factors have been reported to co-localize with CTCF and regulate CTCF loops, but no comprehensive analysis of binding partners has been performed. This prompted us to identify CTCF loop participants and regulators by co-localization analysis with CTCF. We screened all factors that had ChIP-seq data in humans by co-localization analysis with human super conserved CTCF (hscCTCF) binding sites, and identified many new factors that overlapped with hscCTCF binding sites. Combined with CTCF loop information, we observed that clustered factors could promote CTCF loops. After in-depth mining of each factor, we found that many factors might have the potential to promote CTCF loops. Our data further demonstrated that BHLHE40 affected CTCF loops by regulating CTCF binding. Together, this study revealed that many factors have the potential to participate in or regulate CTCF loops, and discovered a new role for BHLHE40 in modulating CTCF loop formation.
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Affiliation(s)
- Gongcheng Hu
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China.,Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Bioland Laboratory (Guangzhou Regenerative Medicine and Health GuangDong Laboratory), Guangzhou 510005, China.,Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaotao Dong
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China.,Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Bioland Laboratory (Guangzhou Regenerative Medicine and Health GuangDong Laboratory), Guangzhou 510005, China.,Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shixin Gong
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China.,Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Bioland Laboratory (Guangzhou Regenerative Medicine and Health GuangDong Laboratory), Guangzhou 510005, China.,Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yawei Song
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China.,Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Bioland Laboratory (Guangzhou Regenerative Medicine and Health GuangDong Laboratory), Guangzhou 510005, China.,Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Andrew P Hutchins
- Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hongjie Yao
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China.,Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Bioland Laboratory (Guangzhou Regenerative Medicine and Health GuangDong Laboratory), Guangzhou 510005, China.,Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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18
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Meyer-Nava S, Nieto-Caballero VE, Zurita M, Valadez-Graham V. Insights into HP1a-Chromatin Interactions. Cells 2020; 9:E1866. [PMID: 32784937 PMCID: PMC7465937 DOI: 10.3390/cells9081866] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/18/2020] [Accepted: 07/21/2020] [Indexed: 12/17/2022] Open
Abstract
Understanding the packaging of DNA into chromatin has become a crucial aspect in the study of gene regulatory mechanisms. Heterochromatin establishment and maintenance dynamics have emerged as some of the main features involved in genome stability, cellular development, and diseases. The most extensively studied heterochromatin protein is HP1a. This protein has two main domains, namely the chromoshadow and the chromodomain, separated by a hinge region. Over the years, several works have taken on the task of identifying HP1a partners using different strategies. In this review, we focus on describing these interactions and the possible complexes and subcomplexes associated with this critical protein. Characterization of these complexes will help us to clearly understand the implications of the interactions of HP1a in heterochromatin maintenance, heterochromatin dynamics, and heterochromatin's direct relationship to gene regulation and chromatin organization.
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Affiliation(s)
| | | | | | - Viviana Valadez-Graham
- Instituto de Biotecnología, Departamento de Genética del Desarrollo y Fisiología Molecular, Universidad Nacional Autónoma de México, Cuernavaca Morelos 62210, Mexico; (S.M.-N.); (V.E.N.-C.); (M.Z.)
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19
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Wu Q, Liu P, Wang L. Many facades of CTCF unified by its coding for three-dimensional genome architecture. J Genet Genomics 2020; 47:407-424. [PMID: 33187878 DOI: 10.1016/j.jgg.2020.06.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 04/15/2020] [Accepted: 06/01/2020] [Indexed: 02/06/2023]
Abstract
CCCTC-binding factor (CTCF) is a multifunctional zinc finger protein that is conserved in metazoan species. CTCF is consistently found to play an important role in many diverse biological processes. CTCF/cohesin-mediated active chromatin 'loop extrusion' architects three-dimensional (3D) genome folding. The 3D architectural role of CTCF underlies its multifarious functions, including developmental regulation of gene expression, protocadherin (Pcdh) promoter choice in the nervous system, immunoglobulin (Ig) and T-cell receptor (Tcr) V(D)J recombination in the immune system, homeobox (Hox) gene control during limb development, as well as many other aspects of biology. Here, we review the pleiotropic functions of CTCF from the perspective of its essential role in 3D genome architecture and topological promoter/enhancer selection. We envision the 3D genome as an enormous complex architecture, with tens of thousands of CTCF sites as connecting nodes and CTCF proteins as mysterious bonds that glue together genomic building parts with distinct articulation joints. In particular, we focus on the internal mechanisms by which CTCF controls higher order chromatin structures that manifest its many façades of physiological and pathological functions. We also discuss the dichotomic role of CTCF sites as intriguing 3D genome nodes for seemingly contradictory 'looping bridges' and 'topological insulators' to frame a beautiful magnificent house for a cell's nuclear home.
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Affiliation(s)
- Qiang Wu
- MOE Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Center for Comparative Biomedicine, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University (SJTU), Shanghai, 200240, China.
| | - Peifeng Liu
- MOE Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Center for Comparative Biomedicine, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University (SJTU), Shanghai, 200240, China
| | - Leyang Wang
- MOE Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Center for Comparative Biomedicine, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University (SJTU), Shanghai, 200240, China
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20
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Demarcation of Topologically Associating Domains Is Uncoupled from Enriched CTCF Binding in Developing Zebrafish. iScience 2020; 23:101046. [PMID: 32334414 PMCID: PMC7182764 DOI: 10.1016/j.isci.2020.101046] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 03/19/2020] [Accepted: 04/03/2020] [Indexed: 11/21/2022] Open
Abstract
CCCTC-binding factor (CTCF) is a conserved architectural protein that plays crucial roles in gene regulation and three-dimensional (3D) chromatin organization. To better understand mechanisms and evolution of vertebrate genome organization, we analyzed genome occupancy of CTCF in zebrafish utilizing an endogenously epitope-tagged CTCF knock-in allele. Zebrafish CTCF shares similar facets with its mammalian counterparts, including binding to enhancers, active promoters and repeat elements, and bipartite sequence motifs of its binding sites. However, we found that in vivo CTCF binding is not enriched at boundaries of topologically associating domains (TADs) in developing zebrafish, whereas TAD demarcation by chromatin marks did not differ from mammals. Our data suggest that general mechanisms underlying 3D chromatin organization, and in particular the involvement of CTCF in this process, differ between distant vertebrate species. Identification of CTCF occupancy in zebrafish embryos using a tagged ctcf allele CTCF binding at promoters correlates with gene expression levels No general CTCF enrichment at topological domain boundaries in zebrafish embryos
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21
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N-terminal domain of the architectural protein CTCF has similar structural organization and ability to self-association in bilaterian organisms. Sci Rep 2020; 10:2677. [PMID: 32060375 PMCID: PMC7021899 DOI: 10.1038/s41598-020-59459-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 01/24/2020] [Indexed: 12/12/2022] Open
Abstract
CTCF is the main architectural protein found in most of the examined bilaterian organisms. The cluster of the C2H2 zinc-finger domains involved in recognition of long DNA-binding motif is only part of the protein that is evolutionarily conserved, while the N-terminal domain (NTD) has different sequences. Here, we performed biophysical characterization of CTCF NTDs from various species representing all major phylogenetic clades of higher metazoans. With the exception of Drosophilides, the N-terminal domains of CTCFs show an unstructured organization and absence of folded regions in vitro. In contrast, NTDs of Drosophila melanogaster and virilis CTCFs contain unstructured folded regions that form tetramers and dimers correspondingly in vitro. Unexpectedly, most NTDs are able to self-associate in the yeast two-hybrid and co-immunoprecipitation assays. These results suggest that NTDs of CTCFs might contribute to the organization of CTCF-mediated long-distance interactions and chromosomal architecture.
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22
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In situ dissection of domain boundaries affect genome topology and gene transcription in Drosophila. Nat Commun 2020; 11:894. [PMID: 32060283 PMCID: PMC7021724 DOI: 10.1038/s41467-020-14651-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 01/23/2020] [Indexed: 02/06/2023] Open
Abstract
Chromosomes are organized into high-frequency chromatin interaction domains called topologically associating domains (TADs), which are separated from each other by domain boundaries. The molecular mechanisms responsible for TAD formation are not yet fully understood. In Drosophila, it has been proposed that transcription is fundamental for TAD organization while the participation of genetic sequences bound by architectural proteins (APs) remains controversial. Here, we investigate the contribution of domain boundaries to TAD organization and the regulation of gene expression at the Notch gene locus in Drosophila. We find that deletion of domain boundaries results in TAD fusion and long-range topological defects that are accompanied by loss of APs and RNA Pol II chromatin binding as well as defects in transcription. Together, our results provide compelling evidence of the contribution of discrete genetic sequences bound by APs and RNA Pol II in the partition of the genome into TADs and in the regulation of gene expression in Drosophila. In Drosophila, transcription is thought to be required for TAD formation, while the role of architectural proteins remains controversial. Here, the authors find that deletion of domain boundaries at the fly Notch locus results in TAD fusion and long-range topological defects, loss of architectural protein and RNA Pol II chromatin binding, and transcription defects.
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23
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Schomburg C, Turetzek N, Prpic NM. Candidate gene screen for potential interaction partners and regulatory targets of the Hox gene labial in the spider Parasteatoda tepidariorum. Dev Genes Evol 2020; 230:105-120. [PMID: 32036446 PMCID: PMC7128011 DOI: 10.1007/s00427-020-00656-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 01/31/2020] [Indexed: 12/21/2022]
Abstract
The Hox gene labial (lab) governs the formation of the tritocerebral head segment in insects and spiders. However, the morphology that results from lab action is very different in the two groups. In insects, the tritocerebral segment (intercalary segment) is reduced and lacks appendages, whereas in spiders the corresponding segment (pedipalpal segment) is a proper segment including a pair of appendages (pedipalps). It is likely that this difference between lab action in insects and spiders is mediated by regulatory targets or interacting partners of lab. However, only a few such genes are known in insects and none in spiders. We have conducted a candidate gene screen in the spider Parasteatoda tepidariorum using as candidates Drosophila melanogaster genes known to (potentially) interact with lab or to be expressed in the intercalary segment. We have studied 75 P. tepidariorum genes (including previously published and duplicated genes). Only 3 of these (proboscipedia-A (pb-A) and two paralogs of extradenticle (exd)) showed differential expression between leg and pedipalp. The low success rate points to a weakness of the candidate gene approach when it is applied to lineage specific organs. The spider pedipalp has no counterpart in insects, and therefore relying on insect data apparently cannot identify larger numbers of factors implicated in its specification and formation. We argue that in these cases a de novo approach to gene discovery might be superior to the candidate gene approach.
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Affiliation(s)
- Christoph Schomburg
- Institut für Allgemeine Zoologie und Entwicklungsbiologie, AG Zoologie mit dem Schwerpunkt Molekulare Entwicklungsbiologie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 38, 35392, Gießen, Germany
| | - Natascha Turetzek
- Ludwig-Maximilians-Universität München, Lehrstuhl für Evolutionäre Ökologie, Biozentrum II, Großhadernerstraße 2, 82152, Planegg-Martinsried, Germany
| | - Nikola-Michael Prpic
- Institut für Allgemeine Zoologie und Entwicklungsbiologie, AG Zoologie mit dem Schwerpunkt Molekulare Entwicklungsbiologie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 38, 35392, Gießen, Germany.
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24
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Kentepozidou E, Aitken SJ, Feig C, Stefflova K, Ibarra-Soria X, Odom DT, Roller M, Flicek P. Clustered CTCF binding is an evolutionary mechanism to maintain topologically associating domains. Genome Biol 2020; 21:5. [PMID: 31910870 PMCID: PMC6945661 DOI: 10.1186/s13059-019-1894-x] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 11/21/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND CTCF binding contributes to the establishment of a higher-order genome structure by demarcating the boundaries of large-scale topologically associating domains (TADs). However, despite the importance and conservation of TADs, the role of CTCF binding in their evolution and stability remains elusive. RESULTS We carry out an experimental and computational study that exploits the natural genetic variation across five closely related species to assess how CTCF binding patterns stably fixed by evolution in each species contribute to the establishment and evolutionary dynamics of TAD boundaries. We perform CTCF ChIP-seq in multiple mouse species to create genome-wide binding profiles and associate them with TAD boundaries. Our analyses reveal that CTCF binding is maintained at TAD boundaries by a balance of selective constraints and dynamic evolutionary processes. Regardless of their conservation across species, CTCF binding sites at TAD boundaries are subject to stronger sequence and functional constraints compared to other CTCF sites. TAD boundaries frequently harbor dynamically evolving clusters containing both evolutionarily old and young CTCF sites as a result of the repeated acquisition of new species-specific sites close to conserved ones. The overwhelming majority of clustered CTCF sites colocalize with cohesin and are significantly closer to gene transcription start sites than nonclustered CTCF sites, suggesting that CTCF clusters particularly contribute to cohesin stabilization and transcriptional regulation. CONCLUSIONS Dynamic conservation of CTCF site clusters is an apparently important feature of CTCF binding evolution that is critical to the functional stability of a higher-order chromatin structure.
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Affiliation(s)
- Elissavet Kentepozidou
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, CB10 1SD UK
| | - Sarah J. Aitken
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE UK
- Department of Histopathology, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Hills Road, Cambridge, CB2 0QQ UK
| | - Christine Feig
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE UK
| | - Klara Stefflova
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE UK
| | - Ximena Ibarra-Soria
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE UK
| | - Duncan T. Odom
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE UK
- Division Regulatory Genomics and Cancer Evolution, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Maša Roller
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, CB10 1SD UK
| | - Paul Flicek
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, CB10 1SD UK
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE UK
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA UK
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25
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Small Drosophila zinc finger C2H2 protein with an N-terminal zinc finger-associated domain demonstrates the architecture functions. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1863:194446. [PMID: 31706027 DOI: 10.1016/j.bbagrm.2019.194446] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/26/2019] [Accepted: 10/29/2019] [Indexed: 02/08/2023]
Abstract
Recently, the concept has arisen that a special class of architectural proteins exists, which are responsible not only for global chromosome architecture but also for the local regulation of enhancer-promoter interactions. Here, we describe a new architectural protein, with a total size of only 375 aa, which contains an N-terminal zinc finger-associated domain (ZAD) and a cluster of five zinc finger C2H2 domains at the C-terminus. This new protein, named ZAD and Architectural Function 1 protein (ZAF1 protein), is weakly and ubiquitously expressed, with the highest expression levels observed in oocytes and embryos. The cluster of C2H2 domains recognizes a specific 15-bp consensus site, located predominantly in promoters, near transcription start sites. The expression of ZAF1 by a tissue-specific promoter led to the complete blocking of the eye enhancer when clusters of ZAF1 binding sites flanked the eye enhancer in transgenic lines, suggesting that the loop formed by the ZAF1 protein leads to insulation. The ZAF1 protein also supported long-range interactions between the yeast GAL4 activator and the white promoter in transgenic Drosophila lines. A mutant protein lacking the ZAD failed to block the eye enhancer or to support distance interactions in transgenic lines. Taken together, these results suggest that ZAF1 is a minimal architectural protein that can be used to create a convenient model for studying the mechanisms of distance interactions.
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26
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Kyrchanova O, Wolle D, Sabirov M, Kurbidaeva A, Aoki T, Maksimenko O, Kyrchanova M, Georgiev P, Schedl P. Distinct Elements Confer the Blocking and Bypass Functions of the Bithorax Fab-8 Boundary. Genetics 2019; 213:865-876. [PMID: 31551239 PMCID: PMC6827379 DOI: 10.1534/genetics.119.302694] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 09/12/2019] [Indexed: 01/05/2023] Open
Abstract
Boundaries in the Drosophila bithorax complex (BX-C) enable the regulatory domains that drive parasegment-specific expression of the three Hox genes to function autonomously. The four regulatory domains (iab-5, iab-6, iab-7, and iab-8) that control the expression of the Abdominal-B (Abd-B) gene are located downstream of the transcription unit, and are delimited by the Mcp, Fab-6, Fab-7, and Fab-8 boundaries. These boundaries function to block cross talk between neighboring regulatory domains. In addition, three of the boundaries (Fab-6, Fab-7, and Fab-8) must also have bypass activity so that regulatory domains distal to the boundaries can contact the Abd-B promoter. In the studies reported here, we have undertaken a functional dissection of the Fab-8 boundary using a boundary-replacement strategy. Our studies indicate that the Fab-8 boundary has two separable subelements. The distal subelement blocks cross talk, but cannot support bypass. The proximal subelement has only minimal blocking activity but is able to mediate bypass. A large multiprotein complex, the LBC (large boundary complex), binds to sequences in the proximal subelement and contributes to its bypass activity. The same LBC complex has been implicated in the bypass activity of the Fab-7 boundary.
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Affiliation(s)
- Olga Kyrchanova
- Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, Moscow 119334, Russia
| | - Daniel Wolle
- Department of Molecular Biology, Princeton University, New Jersey 08544
| | - Marat Sabirov
- Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, Moscow 119334, Russia
| | - Amina Kurbidaeva
- Department of Molecular Biology, Princeton University, New Jersey 08544
| | - Tsutomu Aoki
- Department of Molecular Biology, Princeton University, New Jersey 08544
| | - Oksana Maksimenko
- Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, Moscow 119334, Russia
| | - Maria Kyrchanova
- Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, Moscow 119334, Russia
| | - Pavel Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, Moscow 119334, Russia
| | - Paul Schedl
- Department of Molecular Biology, Princeton University, New Jersey 08544
- Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology Russian Academy of Sciences, Moscow 119334, Russia
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27
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The Role of Insulation in Patterning Gene Expression. Genes (Basel) 2019; 10:genes10100767. [PMID: 31569427 PMCID: PMC6827083 DOI: 10.3390/genes10100767] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 12/16/2022] Open
Abstract
Development is orchestrated by regulatory elements that turn genes ON or OFF in precise spatial and temporal patterns. Many safety mechanisms prevent inappropriate action of a regulatory element on the wrong gene promoter. In flies and mammals, dedicated DNA elements (insulators) recruit protein factors (insulator binding proteins, or IBPs) to shield promoters from regulatory elements. In mammals, a single IBP called CCCTC-binding factor (CTCF) is known, whereas genetic and biochemical analyses in Drosophila have identified a larger repertoire of IBPs. How insulators function at the molecular level is not fully understood, but it is currently thought that they fold chromosomes into conformations that affect regulatory element-promoter communication. Here, we review the discovery of insulators and describe their properties. We discuss recent genetic studies in flies and mice to address the question: Is gene insulation important for animal development? Comparing and contrasting observations in these two species reveal that they have different requirements for insulation, but that insulation is a conserved and critical gene regulation strategy.
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28
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Matthews NE, White R. Chromatin Architecture in the Fly: Living without CTCF/Cohesin Loop Extrusion?: Alternating Chromatin States Provide a Basis for Domain Architecture in Drosophila. Bioessays 2019; 41:e1900048. [PMID: 31264253 DOI: 10.1002/bies.201900048] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/08/2019] [Indexed: 12/15/2022]
Abstract
The organization of the genome into topologically associated domains (TADs) appears to be a fundamental process occurring across a wide range of eukaryote organisms, and it likely plays an important role in providing an architectural foundation for gene regulation. Initial studies emphasized the remarkable parallels between TAD organization in organisms as diverse as Drosophila and mammals. However, whereas CCCTC-binding factor (CTCF)/cohesin loop extrusion is emerging as a key mechanism for the formation of mammalian topological domains, the genome organization in Drosophila appears to depend primarily on the partitioning of chromatin state domains. Recent work suggesting a fundamental conserved role of chromatin state in building domain architecture is discussed and insights into genome organization from recent studies in Drosophila are considered.
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Affiliation(s)
- Nicholas E Matthews
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3DY, UK
| | - Rob White
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3DY, UK
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29
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Postika NE, Ivlieva TA, Georgiev PG, Kyrchanova OV. Study of dCTCF Insulator Activity in Drosophilamelanogaster Model Systems. DOKL BIOCHEM BIOPHYS 2019; 486:187-191. [PMID: 31367818 DOI: 10.1134/s1607672919030074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Indexed: 11/23/2022]
Abstract
Using transgenic Drosophila model systems, we showed that four binding sites for the architectural protein dCTCF per se cannot form an effective insulator that blocks enhancers and protects against the Polycomb-dependent repression. These results suggest that, in the known Drosophila insulators, the dCTCF protein functions in cooperation with other architectural proteins.
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Affiliation(s)
- N E Postika
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia.
| | - T A Ivlieva
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia
| | - P G Georgiev
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia
| | - O V Kyrchanova
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia
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30
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Booms A, Coetzee GA, Pierce SE. MCF-7 as a Model for Functional Analysis of Breast Cancer Risk Variants. Cancer Epidemiol Biomarkers Prev 2019; 28:1735-1745. [PMID: 31292138 DOI: 10.1158/1055-9965.epi-19-0066] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 05/17/2019] [Accepted: 07/02/2019] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Breast cancer genetic predisposition is governed by more than 142 loci as revealed by genome-wide association studies (GWAS). The functional contribution of these risk loci to breast cancer remains unclear, and additional post-GWAS analyses are required. METHODS We identified active regulatory elements (enhancers, promoters, and chromatin organizing elements) by histone H3K27 acetylation and CTCF occupancy and determined the enrichment of risk variants at these sites. We compared these results with previously published data and for other cell lines, including human mammary epithelial cells, and related these data to gene expression. RESULTS In terms of mapping accuracy and resolution, our data augment previous annotations of the MCF-7 epigenome. After intersection with GWAS risk variants, we found 39 enhancers and 15 CTCF occupancy sites that, between them, overlapped 96 breast cancer credible risk variants at 42 loci. These risk enhancers likely regulate the expression of dozens of genes, which are enriched for GO categories, including estrogen and prolactin signaling. CONCLUSIONS Ten (of 142) breast cancer risk loci likely function via enhancers that are active in MCF-7 and are well suited to targeted manipulation in this system. In contrast, risk loci cannot be mapped to specific CTCF-binding sites, and the genes linked to risk CTCF sites did not show functional enrichment. The identity of risk enhancers and their associated genes suggests that some risk may function during later processes in cancer progression. IMPACT Here, we report how the ER+ cell line MCF-7 can be used to dissect risk mechanisms for breast cancer.
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Affiliation(s)
- Alix Booms
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, Michigan
| | - Gerhard A Coetzee
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, Michigan.
| | - Steven E Pierce
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, Michigan
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31
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Konrad EDH, Nardini N, Caliebe A, Nagel I, Young D, Horvath G, Santoro SL, Shuss C, Ziegler A, Bonneau D, Kempers M, Pfundt R, Legius E, Bouman A, Stuurman KE, Õunap K, Pajusalu S, Wojcik MH, Vasileiou G, Le Guyader G, Schnelle HM, Berland S, Zonneveld-Huijssoon E, Kersten S, Gupta A, Blackburn PR, Ellingson MS, Ferber MJ, Dhamija R, Klee EW, McEntagart M, Lichtenbelt KD, Kenney A, Vergano SA, Abou Jamra R, Platzer K, Ella Pierpont M, Khattar D, Hopkin RJ, Martin RJ, Jongmans MCJ, Chang VY, Martinez-Agosto JA, Kuismin O, Kurki MI, Pietiläinen O, Palotie A, Maarup TJ, Johnson DS, Venborg Pedersen K, Laulund LW, Lynch SA, Blyth M, Prescott K, Canham N, Ibitoye R, Brilstra EH, Shinawi M, Fassi E, Sticht H, Gregor A, Van Esch H, Zweier C. CTCF variants in 39 individuals with a variable neurodevelopmental disorder broaden the mutational and clinical spectrum. Genet Med 2019; 21:2723-2733. [PMID: 31239556 PMCID: PMC6892744 DOI: 10.1038/s41436-019-0585-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 06/06/2019] [Indexed: 12/28/2022] Open
Abstract
Purpose Pathogenic variants in the chromatin organizer CTCF were previously reported in seven individuals
with a neurodevelopmental disorder (NDD). Methods Through international collaboration we collected data from 39
subjects with variants in CTCF. We performed
transcriptome analysis on RNA from blood samples and utilized Drosophila melanogaster to investigate the impact
of Ctcf dosage alteration on nervous system
development and function. Results The individuals in our cohort carried 2 deletions, 8 likely
gene-disruptive, 2 splice-site, and 20 different missense variants, most of them
de novo. Two cases were familial. The associated phenotype was of variable
severity extending from mild developmental delay or normal IQ to severe
intellectual disability. Feeding difficulties and behavioral abnormalities were
common, and variable other findings including growth restriction and cardiac
defects were observed. RNA-sequencing in five individuals identified 3828
deregulated genes enriched for known NDD genes and biological processes such as
transcriptional regulation. Ctcf dosage
alteration in Drosophila resulted in impaired
gross neurological functioning and learning and memory deficits. Conclusion We significantly broaden the mutational and clinical spectrum ofCTCF-associated NDDs. Our data shed light
onto the functional role of CTCF by identifying deregulated genes and show that
Ctcf alterations result in nervous system defects in Drosophila.
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Affiliation(s)
- Enrico D H Konrad
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Niels Nardini
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Almuth Caliebe
- Institute of Human Genetics, Universitätsklinikum Schleswig Holstein Campus Kiel and Christian-Albrechts-Universität, Kiel, Germany
| | - Inga Nagel
- Institute of Human Genetics, Universitätsklinikum Schleswig Holstein Campus Kiel and Christian-Albrechts-Universität, Kiel, Germany.,Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Dana Young
- Adult Metabolic Diseases Clinic, Vancouver General Hospital, Vancouver, BC, Canada
| | - Gabriella Horvath
- Adult Metabolic Diseases Clinic, Vancouver General Hospital, Vancouver, BC, Canada
| | - Stephanie L Santoro
- Division of Molecular and Human Genetics, Nationwide Children's Hospital, Columbus, OH, USA
| | - Christine Shuss
- Division of Molecular and Human Genetics, Nationwide Children's Hospital, Columbus, OH, USA
| | - Alban Ziegler
- Département de Biochimie et Génétique, CHU Angers et Mitolab INSERM 1083-CNRS 6015, Angers, France
| | - Dominique Bonneau
- Département de Biochimie et Génétique, CHU Angers et Mitolab INSERM 1083-CNRS 6015, Angers, France
| | - Marlies Kempers
- Department of Human Genetics, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Eric Legius
- Department of Human Genetics, KU Leuven and Center for Human Genetics, University Hospital Leuven, KU Leuven, Leuven, Belgium
| | - Arjan Bouman
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Kyra E Stuurman
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Katrin Õunap
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia.,Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia.,The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sander Pajusalu
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia.,Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia.,Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Monica H Wojcik
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Divisions of Genetics and Genomics and Newborn Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA
| | - Georgia Vasileiou
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | | | - Hege M Schnelle
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Siren Berland
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Evelien Zonneveld-Huijssoon
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Simone Kersten
- Department of Human Genetics, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Aditi Gupta
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
| | - Patrick R Blackburn
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Marissa S Ellingson
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Matthew J Ferber
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Radhika Dhamija
- Department of Clinical Genomics, Mayo Clinic, Scottsdale, AZ, USA
| | - Eric W Klee
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
| | - Meriel McEntagart
- South West Thames Regional Genetics Centre, St. George's Healthcare NHS Trust, St. George's, University of London, London, UK
| | - Klaske D Lichtenbelt
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Amy Kenney
- Division of Medical Genetics and Metabolism, Children's Hospital of The King's Daughters, Norfolk, VA, USA
| | - Samantha A Vergano
- Division of Medical Genetics and Metabolism, Children's Hospital of The King's Daughters, Norfolk, VA, USA
| | - Rami Abou Jamra
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Konrad Platzer
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Mary Ella Pierpont
- Department of Pediatrics, Division of Genetics and Metabolism, University of Minnesota, Minneapolis, MN, USA
| | - Divya Khattar
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Robert J Hopkin
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Richard J Martin
- The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Marjolijn C J Jongmans
- Department of Human Genetics, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Vivian Y Chang
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, David Geffen School of Medicine, Los Angeles, CA, USA.,Jonsson Comprehensive Cancer Center, University of California, Los Angeles, CA, USA
| | - Julian A Martinez-Agosto
- Division of Medical Genetics, Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.,Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Outi Kuismin
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland.,PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center, Oulu University Hospital, University of Oulu, Oulu, Finland.,Department of Clinical Genetics, Oulu University Hospital, Oulu, Finland
| | - Mitja I Kurki
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland.,Psychiatric & Neurodevelopmental Genetics Unit, Massachusetts General Hospital, Boston, MA, USA.,The Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Olli Pietiläinen
- The Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Department of Stem Cell and Regenerative Biology, University of Harvard, Cambridge, MA, USA
| | - Aarno Palotie
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland.,Psychiatric & Neurodevelopmental Genetics Unit, Massachusetts General Hospital, Boston, MA, USA.,The Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | | | | | | | - Lone W Laulund
- Department of Pediatrics, Odense University Hospital, Odense, Denmark
| | - Sally A Lynch
- University College Dublin and Temple Street Children's Hospital, Dublin, Ireland
| | - Moira Blyth
- Yorkshire Regional Genetics Service, Chapel Allerton Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - Katrina Prescott
- Yorkshire Regional Genetics Service, Chapel Allerton Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - Natalie Canham
- North West Thames Regional Genetics Service, Northwick Park Hospital, Harrow, UK
| | - Rita Ibitoye
- North West Thames Regional Genetics Service, Northwick Park Hospital, Harrow, UK
| | - Eva H Brilstra
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marwan Shinawi
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | - Emily Fassi
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | | | - Heinrich Sticht
- Institute of Biochemistry, Emil-Fischer Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Anne Gregor
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Hilde Van Esch
- Center for Human Genetics, University Hospital Leuven, KU Leuven, Leuven, Belgium
| | - Christiane Zweier
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
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Complete reconstitution of bypass and blocking functions in a minimal artificial Fab-7 insulator from Drosophila bithorax complex. Proc Natl Acad Sci U S A 2019; 116:13462-13467. [PMID: 31209019 DOI: 10.1073/pnas.1907190116] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Boundaries in the bithorax complex (BX-C) delimit autonomous regulatory domains that drive parasegment-specific expression of the Hox genes Ubx, abd-A, and Abd-B The Fab-7 boundary is located between the iab-6 and iab-7 domains and has two key functions: blocking cross-talk between these domains and at the same time promoting communication (boundary bypass) between iab-6 and the Abd-B promoter. Using a replacement strategy, we found that multimerized binding sites for the architectural proteins Pita, Su(Hw), and dCTCF function as conventional insulators and block cross-talk between the iab-6 and iab-7 domains; however, they lack bypass activity, and iab-6 is unable to regulate Abd-B Here we show that an ∼200-bp sequence of dHS1 from the Fab-7 boundary rescues the bypass defects of these multimerized binding sites. The dHS1 sequence is bound in embryos by a large multiprotein complex, Late Boundary Complex (LBC), that contains the zinc finger proteins CLAMP and GAF. Using deletions and mutations in critical GAGAG motifs, we show that bypass activity correlates with the efficiency of recruitment of LBC components CLAMP and GAF to the artificial boundary. These results indicate that LBC orchestrates long-distance communication between the iab-6 regulatory domain and the Abd-B gene, while the Pita, Su(Hw), and dCTCF proteins function to block local cross-talk between the neighboring regulatory domains iab-6 and iab-7.
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33
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Piwko P, Vitsaki I, Livadaras I, Delidakis C. The Role of Insulators in Transgene Transvection in Drosophila. Genetics 2019; 212:489-508. [PMID: 30948430 PMCID: PMC6553826 DOI: 10.1534/genetics.119.302165] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/02/2019] [Indexed: 12/19/2022] Open
Abstract
Transvection is the phenomenon where a transcriptional enhancer activates a promoter located on the homologous chromosome. It has been amply documented in Drosophila where homologs are closely paired in most, if not all, somatic nuclei, but it has been known to rarely occur in mammals as well. We have taken advantage of site-directed transgenesis to insert reporter constructs into the same genetic locus in Drosophila and have evaluated their ability to engage in transvection by testing many heterozygous combinations. We find that transvection requires the presence of an insulator element on both homologs. Homotypic trans-interactions between four different insulators can support transvection: the gypsy insulator (GI), Wari, Fab-8 and 1A2; GI and Fab-8 are more effective than Wari or 1A2 We show that, in the presence of insulators, transvection displays the characteristics that have been previously described: it requires homolog pairing, but can happen at any of several loci in the genome; a solitary enhancer confronted with an enhancerless reporter is sufficient to drive transcription; it is weaker than the action of the same enhancer-promoter pair in cis, and it is further suppressed by cis-promoter competition. Though necessary, the presence of homotypic insulators is not sufficient for transvection; their position, number and orientation matters. A single GI adjacent to both enhancer and promoter is the optimal configuration. The identity of enhancers and promoters in the vicinity of a trans-interacting insulator pair is also important, indicative of complex insulator-enhancer-promoter interactions.
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Affiliation(s)
- Pawel Piwko
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
- Department of Biology, University of Crete, Heraklion 70013, Crete, Greece
| | - Ilektra Vitsaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
- Department of Biology, University of Crete, Heraklion 70013, Crete, Greece
| | - Ioannis Livadaras
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
| | - Christos Delidakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
- Department of Biology, University of Crete, Heraklion 70013, Crete, Greece
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34
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Braccioli L, de Wit E. CTCF: a Swiss-army knife for genome organization and transcription regulation. Essays Biochem 2019; 63:157-165. [PMID: 30940740 DOI: 10.1042/ebc20180069] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/08/2019] [Accepted: 03/11/2019] [Indexed: 12/11/2022]
Abstract
Orchestrating vertebrate genomes require a complex interplay between the linear composition of the genome and its 3D organization inside the nucleus. This requires the function of specialized proteins, able to tune various aspects of genome organization and gene regulation. The CCCTC-binding factor (CTCF) is a DNA binding factor capable of regulating not only the 3D genome organization, but also key aspects of gene expression, including transcription activation and repression, RNA splicing, and enhancer/promoter insulation. A growing body of evidence proposes that CTCF, together with cohesin contributes to DNA loop formation and 3D genome organization. CTCF binding sites are mutation hotspots in cancer, while mutations in CTCF itself lead to intellectual disabilities, emphasizing its importance in disease etiology. In this review we cover various aspects of CTCF function, revealing the polyvalence of this factor as a highly diversified tool for vertebrate genome organization and transcription regulation.
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Affiliation(s)
- Luca Braccioli
- Oncode Institute and Division of Gene Regulation, the Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, the Netherlands
| | - Elzo de Wit
- Oncode Institute and Division of Gene Regulation, the Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, the Netherlands
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35
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Postika N, Metzler M, Affolter M, Müller M, Schedl P, Georgiev P, Kyrchanova O. Boundaries mediate long-distance interactions between enhancers and promoters in the Drosophila Bithorax complex. PLoS Genet 2018; 14:e1007702. [PMID: 30540750 PMCID: PMC6306242 DOI: 10.1371/journal.pgen.1007702] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 12/26/2018] [Accepted: 11/16/2018] [Indexed: 11/18/2022] Open
Abstract
Drosophila bithorax complex (BX-C) is one of the best model systems for studying the role of boundaries (insulators) in gene regulation. Expression of three homeotic genes, Ubx, abd-A, and Abd-B, is orchestrated by nine parasegment-specific regulatory domains. These domains are flanked by boundary elements, which function to block crosstalk between adjacent domains, ensuring that they can act autonomously. Paradoxically, seven of the BX-C regulatory domains are separated from their gene target by at least one boundary, and must “jump over” the intervening boundaries. To understand the jumping mechanism, the Mcp boundary was replaced with Fab-7 and Fab-8. Mcp is located between the iab-4 and iab-5 domains, and defines the border between the set of regulatory domains controlling abd-A and Abd-B. When Mcp is replaced by Fab-7 or Fab-8, they direct the iab-4 domain (which regulates abd-A) to inappropriately activate Abd-B in abdominal segment A4. For the Fab-8 replacement, ectopic induction was only observed when it was inserted in the same orientation as the endogenous Fab-8 boundary. A similar orientation dependence for bypass activity was observed when Fab-7 was replaced by Fab-8. Thus, boundaries perform two opposite functions in the context of BX-C–they block crosstalk between neighboring regulatory domains, but at the same time actively facilitate long distance communication between the regulatory domains and their respective target genes. Drosophila bithorax complex (BX-C) is one of a few examples demonstrating in vivo role of boundary/insulator elements in organization of independent chromatin domains. BX-C contains three HOX genes, whose parasegment-specific pattern is controlled by cis-regulatory domains flanked by boundary/insulator elements. Since the boundaries ensure autonomy of adjacent domains, the presence of these elements poses a paradox: how do the domains bypass the intervening boundaries and contact their proper regulatory targets? According to the textbook model, BX-C regulatory domains are able to bypass boundaries because they harbor special promoter targeting sequences. However, contrary to this model, we show here that the boundaries themselves play an active role in directing regulatory domains to their appropriate HOX gene promoter.
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Affiliation(s)
- Nikolay Postika
- Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
| | | | | | | | - Paul Schedl
- Department of Gene Expression Regulation in Development, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Pavel Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- * E-mail: (PG); (OK)
| | - Olga Kyrchanova
- Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- * E-mail: (PG); (OK)
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36
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Loukinov D. Targeting CTCFL/BORIS for the immunotherapy of cancer. Cancer Immunol Immunother 2018; 67:1955-1965. [PMID: 30390146 PMCID: PMC11028242 DOI: 10.1007/s00262-018-2251-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 07/13/2018] [Indexed: 10/27/2022]
Abstract
Cancer vaccines have great potential in the fight against metastatic malignancies. Current anti-tumor immunotherapy is hindered by existing tolerance to tumor-associated antigens (TAA) and tumor escape using various mechanisms, highlighting the need for improved targets for immunotherapy. The cancer-testis antigen CTCFL/BORIS was discovered 16 years ago and possesses all features necessary for an ideal TAA. Recently CTCFL/BORIS has received additional attention as a target expressed in cancer stem cells (CSC). These cells drive tumor growth recurrence, metastasis, and treatment resistance. CTCFL/BORIS silencing leads to senescence and death of CSC. Therefore, an immunotherapeutic strategy that targets CTCFL/BORIS may lead to the selective destruction of CSC and potential eradication of metastatic disease. The high immunotherapeutic potential of CTCFL/BORIS antigen was shown in a stringent 4T1 mouse model of breast cancer. Using these highly metastatic, poorly immunogenic carcinoma cells inoculated into T-helper2 prone mice, we showed that DC fed with recombinant CTCFL/BORIS as an immunogen inhibited tumor growth and reduced the number of metastases in distant organs. About 20% of CTCFL/BORIS immunized animals were tumor free. 50% of animals remained metastasis free. Those having metastasis showed at least tenfold fewer metastases compared to controls. In a rat model of breast cancer, we showed that alphavirus-based CTCFL/BORIS immunotherapy was capable of cancer elimination as we were able to cure 50% of animals. Based on the above data, we believe that translation of CTCFL/BORIS-targeting immunotherapeutic strategies to the clinic will provide new avenues for improving survival of breast cancer patients with advanced metastatic disease.
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Affiliation(s)
- Dmitri Loukinov
- Molecular Pathology Section, Laboratory of Immunogenetics, NIAID/NIH, Twinbrook 1, Room 1329, 5640 Fishers Lane, Rockville, MD, 20852, USA.
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37
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Li M, Ma Z, Roy S, Patel SK, Lane DC, Duffy CR, Cai HN. Selective interactions between diverse STEs organize the ANT-C Hox cluster. Sci Rep 2018; 8:15158. [PMID: 30310129 PMCID: PMC6181975 DOI: 10.1038/s41598-018-33588-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 10/01/2018] [Indexed: 11/09/2022] Open
Abstract
The three-dimensional organization of the eukaryotic genome is important for its structure and function. Recent studies indicate that hierarchies of chromatin loops underlie important aspects of both genomic organization and gene regulation. Looping between insulator or boundary elements interferes with enhancer-promoter communications and limits the spread active or repressive organized chromatin. We have used the SF1 insulator in the Drosophila Antennapedia homeotic gene complex (ANT-C) as a model to study the mechanism and regulation of chromatin looping events. We reported previously that SF1 tethers a transient chromatin loop in the early embryo that insulates the Hox gene Sex comb reduce from the neighbor non-Hox gene fushi tarazu for their independent regulation. To further probe the functional range and connectivity of SF1, we used high-resolution chromosomal conformation capture (3C) to search for SF1 looping partners across ANT-C. We report here the identification of three distal SF1 Tether Elements (STEs) located in the labial, Deformed and Antennapedia Hox gene regions, extending the range of SF1 looping network to the entire complex. These novel STEs are bound by four different combinations of insulator proteins and exhibit distinct behaviors in enhancer block, enhancer-bypass and boundary functions. Significantly, the six STEs we identified so far map to all but one of the major boundaries between repressive and active histone domains, underlining the functional relevance of these long-range chromatin loops in organizing the Hox complex. Importantly, SF1 selectively captured with only 5 STEs out of ~20 sites that display similar insulator binding profiles, indicating that presence of insulator proteins alone is not sufficient to determine looping events. These findings suggest that selective interaction among diverse STE insulators organize the Drosophila Hox genes in the 3D nuclear space.
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Affiliation(s)
- Mo Li
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Zhibo Ma
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Sharmila Roy
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Sapna K Patel
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Derrick C Lane
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Carly R Duffy
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Haini N Cai
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA.
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38
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Hug CB, Vaquerizas JM. The Birth of the 3D Genome during Early Embryonic Development. Trends Genet 2018; 34:903-914. [PMID: 30292539 DOI: 10.1016/j.tig.2018.09.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/23/2018] [Accepted: 09/06/2018] [Indexed: 12/15/2022]
Abstract
The 3D structure of chromatin in the nucleus is important for the regulation of gene expression and the correct deployment of developmental programs. The differentiation of germ cells and early embryonic development (when the zygotic genome is activated and transcription is taking place for the first time) are accompanied by dramatic changes in gene expression and the epigenetic landscape. Recent studies used Hi-C to investigate the 3D chromatin organization during these developmental transitions, uncovering remarkable remodeling of the 3D genome. Here, we highlight the changes described so far and discuss some of the implications that these findings have for our understanding of the mechanisms and functionality of 3D chromatin architecture.
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Affiliation(s)
- Clemens B Hug
- Max Planck Institute for Molecular Biomedicine, Roentgenstrasse 20, 48149 Muenster, Germany
| | - Juan M Vaquerizas
- Max Planck Institute for Molecular Biomedicine, Roentgenstrasse 20, 48149 Muenster, Germany. https://twitter.com/vaquerizasjm
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39
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Gambetta MC, Furlong EEM. The Insulator Protein CTCF Is Required for Correct Hox Gene Expression, but Not for Embryonic Development in Drosophila. Genetics 2018; 210:129-136. [PMID: 30021792 PMCID: PMC6116963 DOI: 10.1534/genetics.118.301350] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 07/12/2018] [Indexed: 02/07/2023] Open
Abstract
Insulator binding proteins (IBPs) play an important role in regulating gene expression by binding to specific DNA sites to facilitate appropriate gene regulation. There are several IBPs in Drosophila, each defined by their ability to insulate target gene promoters in transgenic assays from the activating or silencing effects of neighboring regulatory elements. Of these, only CCCTC-binding factor (CTCF) has an obvious ortholog in mammals. CTCF is essential for mammalian cell viability and is an important regulator of genome architecture. In flies, CTCF is both maternally deposited and zygotically expressed. Flies lacking zygotic CTCF die as young adults with homeotic defects, suggesting that specific Hox genes are misexpressed in inappropriate body segments. The lack of any major embryonic defects was assumed to be due to the maternal supply of CTCF protein, as maternally contributed factors are often sufficient to progress through much of embryogenesis. Here, we definitively determined the requirement of CTCF for developmental progression in Drosophila We generated animals that completely lack both maternal and zygotic CTCF and found that, contrary to expectation, these mutants progress through embryogenesis and larval life. They develop to pharate adults, which fail to eclose from their pupal case. These mutants show exacerbated homeotic defects compared to zygotic mutants, misexpressing the Hox gene Abdominal-B outside of its normal expression domain early in development. Our results indicate that loss of Drosophila CTCF is not accompanied by widespread effects on gene expression, which may be due to redundant functions with other IBPs. Rather, CTCF is required for correct Hox gene expression patterns and for the viability of adult Drosophila.
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Affiliation(s)
| | - Eileen E M Furlong
- European Molecular Biology Laboratory, Genome Biology Unit, 69117 Heidelberg, Germany
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40
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Lu D, Li Z, Li L, Yang L, Chen G, Yang D, Zhang Y, Singh V, Smith S, Xiao Y, Wang E, Ye Y, Zhang W, Zhou L, Rong Y, Zhou J. The Ubx Polycomb response element bypasses an unpaired Fab-8 insulator via cis transvection in Drosophila. PLoS One 2018; 13:e0199353. [PMID: 29928011 PMCID: PMC6013190 DOI: 10.1371/journal.pone.0199353] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 06/06/2018] [Indexed: 11/19/2022] Open
Abstract
Chromatin insulators or boundary elements protect genes from regulatory activities from neighboring genes or chromatin domains. In the Drosophila Abdominal-B (Abd-B) locus, the deletion of such elements, such as Frontabdominal-7 (Fab-7) or Fab-8 led to dominant gain of function phenotypes, presumably due to the loss of chromatin barriers. Homologous chromosomes are paired in Drosophila, creating a number of pairing dependent phenomena including transvection, and whether transvection may affect the function of Polycomb response elements (PREs) and thus contribute to the phenotypes are not known. Here, we studied the chromatin barrier activity of Fab-8 and how it is affected by the zygosity of the transgene, and found that Fab-8 is able to block the silencing effect of the Ubx PRE on the DsRed reporter gene in a CTCF binding sites dependent manner. However, the blocking also depends on the zygosity of the transgene in that the barrier activity is present when the transgene is homozygous, but absent when the transgene is heterozygous. To analyze this effect, we performed chromatin immunoprecipitation and quantitative PCR (ChIP-qPCR) experiments on homozygous transgenic embryos, and found that H3K27me3 and H3K9me3 marks are restricted by Fab-8, but they spread beyond Fab-8 into the DsRed gene when the two CTCF binding sites within Fab-8 were mutated. Consistent with this, the mutation reduced H3K4me3 and RNA Pol II binding to the DsRed gene, and consequently, DsRed expression. Importantly, in heterozygous embryos, Fab-8 is unable to prevent the spread of H3K27me3 and H3K9me3 marks from crossing Fab-8 into DsRed, suggesting an insulator bypass. These results suggest that in the Abd-B locus, deletion of the insulator in one copy of the chromosome could lead to the loss of insulator activity on the homologous chromosome, and in other loci where chromosomal deletion created hemizygous regions of the genome, the chromatin barrier could be compromised. This study highlights a role of homologous chromosome pairing in the regulation of gene expression in the Drosophila genome.
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Affiliation(s)
- Danfeng Lu
- Key Laboratory of bioactive peptides of Yunnan Province/ Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
- Graduate School, University of Chinese Academy of Sciences, Beijing, China
| | - Zhuoran Li
- Key Laboratory of bioactive peptides of Yunnan Province/ Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Lingling Li
- State Key Laboratory of Bio-control, Institute of Entomology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Liping Yang
- Key Laboratory of bioactive peptides of Yunnan Province/ Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Guijun Chen
- Key Laboratory of bioactive peptides of Yunnan Province/ Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Deying Yang
- Key Laboratory of bioactive peptides of Yunnan Province/ Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yue Zhang
- Key Laboratory of bioactive peptides of Yunnan Province/ Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Vikrant Singh
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA, United States of America
| | - Sheryl Smith
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA, United States of America
| | - Yu Xiao
- Key Laboratory of bioactive peptides of Yunnan Province/ Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Erlin Wang
- Key Laboratory of bioactive peptides of Yunnan Province/ Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
| | - Yunshuang Ye
- Key Laboratory of bioactive peptides of Yunnan Province/ Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
| | - Wei Zhang
- Key Laboratory of bioactive peptides of Yunnan Province/ Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
| | - Lei Zhou
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL, United States of America
| | - Yikang Rong
- State Key Laboratory of Bio-control, Institute of Entomology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jumin Zhou
- Key Laboratory of bioactive peptides of Yunnan Province/ Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
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Melnikova L, Kostyuchenko M, Molodina V, Parshikov A, Georgiev P, Golovnin A. Multiple interactions are involved in a highly specific association of the Mod(mdg4)-67.2 isoform with the Su(Hw) sites in Drosophila. Open Biol 2018; 7:rsob.170150. [PMID: 29021216 PMCID: PMC5666082 DOI: 10.1098/rsob.170150] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 09/18/2017] [Indexed: 12/13/2022] Open
Abstract
The best-studied Drosophila insulator complex consists of two BTB-containing proteins, the Mod(mdg4)-67.2 isoform and CP190, which are recruited to the chromatin through interactions with the DNA-binding Su(Hw) protein. It was shown previously that Mod(mdg4)-67.2 is critical for the enhancer-blocking activity of the Su(Hw) insulators and it differs from more than 30 other Mod(mdg4) isoforms by the C-terminal domain required for a specific interaction with Su(Hw) only. The mechanism of the highly specific association between Mod(mdg4)-67.2 and Su(Hw) is not well understood. Therefore, we have performed a detailed analysis of domains involved in the interaction of Mod(mdg4)-67.2 with Su(Hw) and CP190. We found that the N-terminal region of Su(Hw) interacts with the glutamine-rich domain common to all the Mod(mdg4) isoforms. The unique C-terminal part of Mod(mdg4)-67.2 contains the Su(Hw)-interacting domain and the FLYWCH domain that facilitates a specific association between Mod(mdg4)-67.2 and the CP190/Su(Hw) complex. Finally, interaction between the BTB domain of Mod(mdg4)-67.2 and the M domain of CP190 has been demonstrated. By using transgenic lines expressing different protein variants, we have shown that all the newly identified interactions are to a greater or lesser extent redundant, which increases the reliability in the formation of the protein complexes.
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Affiliation(s)
- Larisa Melnikova
- Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
| | - Margarita Kostyuchenko
- Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
| | - Varvara Molodina
- Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
| | - Alexander Parshikov
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
| | - Pavel Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
| | - Anton Golovnin
- Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
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Pokholkova GV, Demakov SA, Andreenkov OV, Andreenkova NG, Volkova EI, Belyaeva ES, Zhimulev IF. Tethering of CHROMATOR and dCTCF proteins results in decompaction of condensed bands in the Drosophila melanogaster polytene chromosomes but does not affect their transcription and replication timing. PLoS One 2018; 13:e0192634. [PMID: 29608600 PMCID: PMC5880345 DOI: 10.1371/journal.pone.0192634] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 01/26/2018] [Indexed: 01/20/2023] Open
Abstract
Instulator proteins are central to domain organization and gene regulation in the genome. We used ectopic tethering of CHROMATOR (CHRIZ/CHRO) and dCTCF to pre-defined regions of the genome to dissect the influence of these proteins on local chromatin organization, to analyze their interaction with other key chromatin proteins and to evaluate the effects on transcription and replication. Specifically, using UAS-GAL4DBD system, CHRO and dCTCF were artificially recruited into highly compacted polytene chromosome bands that share the features of silent chromatin type known as intercalary heterochromatin (IH). This led to local chromatin decondensation, formation of novel DHSes and recruitment of several "open chromatin" proteins. CHRO tethering resulted in the recruitment of CP190 and Z4 (PZG), whereas dCTCF tethering attracted CHRO, CP190, and Z4. Importantly, formation of a local stretch of open chromatin did not result in the reactivation of silent marker genes yellow and mini-white immediately adjacent to the targeting region (UAS), nor did RNA polII become recruited into this chromatin. The decompacted region retained late replicated, similarly to the wild-type untargeted region.
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Affiliation(s)
- Galina V. Pokholkova
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences (IMCB RAS), Novosibirsk, Russia
| | - Sergei A. Demakov
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences (IMCB RAS), Novosibirsk, Russia
- Novosibirsk State University (NSU), Novosibirsk, Russia
| | - Oleg V. Andreenkov
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences (IMCB RAS), Novosibirsk, Russia
| | - Natalia G. Andreenkova
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences (IMCB RAS), Novosibirsk, Russia
| | - Elena I. Volkova
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences (IMCB RAS), Novosibirsk, Russia
| | - Elena S. Belyaeva
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences (IMCB RAS), Novosibirsk, Russia
| | - Igor F. Zhimulev
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences (IMCB RAS), Novosibirsk, Russia
- Novosibirsk State University (NSU), Novosibirsk, Russia
- * E-mail:
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43
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Liu J, Ding Z, Li G, Tang L, Xu Y, Luo H, Yi J, Lu Y, Mao R, Nan Q, Ren L, Zhang T, Wang K. Identification and validation of colorectal neoplasia-specific methylation biomarkers based on CTCF-binding sites. Oncotarget 2017; 8:114183-114194. [PMID: 29371978 PMCID: PMC5768395 DOI: 10.18632/oncotarget.23172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 11/22/2017] [Indexed: 12/31/2022] Open
Abstract
To date, the sensitivity of currently available biomarkers based on the methylation of gene promoters is suboptimal for detecting adenomas and early-stage colorectal cancer (CRC). We aimed to develop biomarkers with methylated DNA binding sites of the multifunctional transcriptional factor CTCF for early detection of CRC. Using combined analyses of genome-wide occupation and the methylation profile of CTCF-binding sites, we identified candidate CTCF-binding sites. Then, we applied methylation-sensitive high-resolution melting (MS-HRM) and mass spectrometry analysis to screen and validate these candidate sites in diverse sample sets. We identified a set of colorectal neoplasia-specific biomarkers with robust performance. The top five biomarkers were selected and recommended for early detection of colorectal neoplasia. All of the five novel biomarkers exhibited a more robust discriminatory performance than that by BMP3 and NDRG4, two currently acknowledged robust methylation biomarkers. When the five new biomarkers were considered as a marker panel and tumor-positive was defined as having two or more (of the five) positive biomarkers, the marker panel could achieve a sensitivity of 91.67% for adenomas, 97.44% for Stage I CRC, 94.06% for Stage II CRC, 93.62% for Stage III CRC, and 93.54% for total colorectal tumors with a specificity of 94.05%. To our knowledge, this is the first study for colorectal neoplasia-specific methylation biomarkers based on CTCF-binding sites. Using a similar strategy, CTCF-binding sites could be potentially developed into biomarkers for other tumors. In summary, this study opens a new area in developing biomarkers for tumor prevention and treatment.
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Affiliation(s)
- Jiang Liu
- Department of Reproduction and Genetics, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan, China
| | - Zhaoli Ding
- Public Technical Service Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650032, Yunnan, China.,Kunming Biological Diversity Regional Center of Large Apparatus and Equipments, Chinese Academy of Sciences, Kunming 650032, Yunnan, China
| | - Guimei Li
- Public Technical Service Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650032, Yunnan, China.,Kunming Biological Diversity Regional Center of Large Apparatus and Equipments, Chinese Academy of Sciences, Kunming 650032, Yunnan, China
| | - Li Tang
- Department of Reproduction and Genetics, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan, China
| | - Yu Xu
- Department of Gastrointestinal Surgery, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming 650032, Yunnan, China
| | - Huayou Luo
- Department of Gastrointestinal Surgery, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming 650032, Yunnan, China
| | - Jinhua Yi
- Department of Gastrointestinal Surgery, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming 650032, Yunnan, China
| | - Youwang Lu
- Department of Gastrointestinal Surgery, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming 650032, Yunnan, China
| | - Rui Mao
- School of Stomatology, Kunming Medical University, Kunming 650500, Yunnan, China
| | - Qiong Nan
- Department of Gastroenterology, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming 650032, Yunnan, China
| | - Li Ren
- The First People's Hospital of Yunnan Province, Kunming 650031, Yunnan, China
| | - Tong Zhang
- Department of Gastrointestinal Surgery, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming 650032, Yunnan, China
| | - Kunhua Wang
- Department of Gastrointestinal Surgery, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming 650032, Yunnan, China
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44
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Abstract
CCCTC-binding factor (CTCF) is a conserved, essential regulator of chromatin architecture containing a unique array of 11 zinc fingers (ZFs). Gene duplication and sequence divergence during early amniote evolution generated the CTCF paralog Brother Of the Regulator of Imprinted Sites (BORIS), which has a DNA binding specificity identical to that of CTCF but divergent N- and C-termini. While healthy somatic tissues express only CTCF, CTCF and BORIS are normally co-expressed in meiotic and post-meiotic germ cells, and aberrant activation of BORIS occurs in tumors and some cancer cell lines. This has led to a model in which CTCF and BORIS compete for binding to some but not all genomic target sites; however, regulation of CTCF and BORIS genomic co-occupancy is not well understood. We recently addressed this issue, finding evidence for two major classes of CTCF target sequences, some of which contain single CTCF target sites (1xCTSes) and others containing two adjacent CTCF motifs (2xCTSes). The functional and chromatin structural features of 2xCTSes are distinct from those of 1xCTS-containing regions bound by a CTCF monomer. We suggest that these previously overlooked classes of CTCF binding regions may have different roles in regulating diverse chromatin-based phenomena, and may impact our understanding of heritable epigenetic regulation in cancer cells and normal germ cells.
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Affiliation(s)
- Victor V Lobanenkov
- a Molecular Pathology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health , 5601 Fishers Ln, Rockville , MD , USA
| | - Gabriel E Zentner
- b Department of Biology , Indiana University , 915 E 3rd St, Bloomington , IN 47405 , USA
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45
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Stadler MR, Haines JE, Eisen MB. Convergence of topological domain boundaries, insulators, and polytene interbands revealed by high-resolution mapping of chromatin contacts in the early Drosophila melanogaster embryo. eLife 2017; 6:29550. [PMID: 29148971 PMCID: PMC5739541 DOI: 10.7554/elife.29550] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 11/13/2017] [Indexed: 11/13/2022] Open
Abstract
High-throughput assays of three-dimensional interactions of chromosomes have shed considerable light on the structure of animal chromatin. Despite this progress, the precise physical nature of observed structures and the forces that govern their establishment remain poorly understood. Here we present high resolution Hi-C data from early Drosophila embryos. We demonstrate that boundaries between topological domains of various sizes map to DNA elements that resemble classical insulator elements: short genomic regions sensitive to DNase digestion that are strongly bound by known insulator proteins and are frequently located between divergent promoters. Further, we show a striking correspondence between these elements and the locations of mapped polytene interband regions. We believe it is likely this relationship between insulators, topological boundaries, and polytene interbands extends across the genome, and we therefore propose a model in which decompaction of boundary-insulator-interband regions drives the organization of interphase chromosomes by creating stable physical separation between adjacent domains.
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Affiliation(s)
- Michael R Stadler
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, United States
| | - Jenna E Haines
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, United States
| | - Michael B Eisen
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, United States.,Department of Integrative Biology, University of California, Berkeley, CA, United States.,Howard Hughes Medical Institute, Berkeley, CA, United States
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46
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Ali T, Krüger M, Bhuju S, Jarek M, Bartkuhn M, Renkawitz R. Chromatin binding of Gcn5 in Drosophila is largely mediated by CP190. Nucleic Acids Res 2017; 45:2384-2395. [PMID: 27903907 PMCID: PMC5389606 DOI: 10.1093/nar/gkw1178] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/17/2016] [Indexed: 12/18/2022] Open
Abstract
Centrosomal 190 kDa protein (CP190) is a promoter binding factor, mediates long-range interactions in the context of enhancer-promoter contacts and in chromosomal domain formation. All Drosophila insulator proteins bind CP190 suggesting a crucial role in insulator function. CP190 has major effects on chromatin, such as depletion of nucleosomes, high nucleosomal turnover and prevention of heterochromatin expansion. Here, we searched for enzymes, which might be involved in CP190 mediated chromatin changes. Eighty percent of the genomic binding sites of the histone acetyltransferase Gcn5 are colocalizing with CP190 binding. Depletion of CP190 reduces Gcn5 binding to chromatin. Binding dependency was further supported by Gcn5 mediated co-precipitation of CP190. Gcn5 is known to activate transcription by histone acetylation. We used the dCas9 system to target CP190 or Gcn5 to a Polycomb repressed and H3K27me3 marked gene locus. Both, CP190 as well as Gcn5, activate this locus, thus supporting the model that CP190 recruits Gcn5 and thereby activates chromatin.
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Affiliation(s)
- Tamer Ali
- Institute for Genetics, Justus-Liebig-University, D35392 Giessen, Germany
| | - Marcus Krüger
- CECAD Research Center, University of Cologne, D50931 Cologne, Germany
| | - Sabin Bhuju
- Helmholtz Centre for Infection Research, D38124 Braunschweig, Germany
| | - Michael Jarek
- Helmholtz Centre for Infection Research, D38124 Braunschweig, Germany
| | - Marek Bartkuhn
- Institute for Genetics, Justus-Liebig-University, D35392 Giessen, Germany
| | - Rainer Renkawitz
- Institute for Genetics, Justus-Liebig-University, D35392 Giessen, Germany
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47
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Polycomb-mediated chromatin loops revealed by a subkilobase-resolution chromatin interaction map. Proc Natl Acad Sci U S A 2017; 114:8764-8769. [PMID: 28765367 DOI: 10.1073/pnas.1701291114] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The locations of chromatin loops in Drosophila were determined by Hi-C (chemical cross-linking, restriction digestion, ligation, and high-throughput DNA sequencing). Whereas most loop boundaries or "anchors" are associated with CTCF protein in mammals, loop anchors in Drosophila were found most often in association with the polycomb group (PcG) protein Polycomb (Pc), a subunit of polycomb repressive complex 1 (PRC1). Loops were frequently located within domains of PcG-repressed chromatin. Promoters located at PRC1 loop anchors regulate some of the most important developmental genes and are less likely to be expressed than those not at PRC1 loop anchors. Although DNA looping has most commonly been associated with enhancer-promoter communication, our results indicate that loops are also associated with gene repression.
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48
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Jox T, Buxa MK, Bohla D, Ullah I, Mačinković I, Brehm A, Bartkuhn M, Renkawitz R. Drosophila CP190- and dCTCF-mediated enhancer blocking is augmented by SUMOylation. Epigenetics Chromatin 2017; 10:32. [PMID: 28680483 PMCID: PMC5496309 DOI: 10.1186/s13072-017-0140-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 06/27/2017] [Indexed: 12/02/2022] Open
Abstract
Background Chromatin insulators shield promoters and chromatin domains from neighboring enhancers or chromatin regions with opposing activities. Insulator-binding proteins and their cofactors mediate the boundary function. In general, covalent modification of proteins by the small ubiquitin-like modifier (SUMO) is an important mechanism to control the interaction of proteins within complexes. Results Here we addressed the impact of dSUMO in respect of insulator function, chromatin binding of insulator factors and formation of insulator speckles in Drosophila. SUMOylation augments the enhancer blocking function of four different insulator sequences and increases the genome-wide binding of the insulator cofactor CP190. Conclusions These results indicate that enhanced chromatin binding of SUMOylated CP190 causes fusion of insulator speckles, which may allow for more efficient insulation. Electronic supplementary material The online version of this article (doi:10.1186/s13072-017-0140-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Theresa Jox
- Institute for Genetics, Justus-Liebig-University, 35392 Giessen, Germany.,Institute for Molecular Pathology, UKGM, 35392 Giessen, Germany
| | - Melanie K Buxa
- Institute for Genetics, Justus-Liebig-University, 35392 Giessen, Germany.,Flohr Consult, Adenauerallee 136, 53113 Bonn, Germany
| | - Dorte Bohla
- Institute for Genetics, Justus-Liebig-University, 35392 Giessen, Germany
| | - Ikram Ullah
- Institute of Molecular Biology and Tumour Research, Philipps University Marburg, 35037 Marburg, Germany
| | - Igor Mačinković
- Institute of Molecular Biology and Tumour Research, Philipps University Marburg, 35037 Marburg, Germany
| | - Alexander Brehm
- Institute of Molecular Biology and Tumour Research, Philipps University Marburg, 35037 Marburg, Germany
| | - Marek Bartkuhn
- Institute for Genetics, Justus-Liebig-University, 35392 Giessen, Germany
| | - Rainer Renkawitz
- Institute for Genetics, Justus-Liebig-University, 35392 Giessen, Germany
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49
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Kyrchanova O, Zolotarev N, Mogila V, Maksimenko O, Schedl P, Georgiev P. Architectural protein Pita cooperates with dCTCF in organization of functional boundaries in Bithorax complex. Development 2017; 144:2663-2672. [PMID: 28619827 DOI: 10.1242/dev.149815] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 06/08/2017] [Indexed: 12/11/2022]
Abstract
Boundaries in the Bithorax complex (BX-C) of Drosophila delimit autonomous regulatory domains that drive parasegment-specific expression of homeotic genes. BX-C boundaries have two crucial functions: they must block crosstalk between adjacent regulatory domains and at the same time facilitate boundary bypass. The C2H2 zinc-finger protein Pita binds to several BX-C boundaries, including Fab-7 and Mcp To study Pita functions, we have used a boundary replacement strategy by substituting modified DNAs for the Fab-7 boundary, which is located between the iab-6 and iab-7 regulatory domains. Multimerized Pita sites block iab-6↔iab-7 crosstalk but fail to support iab-6 regulation of Abd-B (bypass). In the case of Fab-7, we used a novel sensitized background to show that the two Pita-binding sites contribute to its boundary function. Although Mcp is from BX-C, it does not function appropriately when substituted for Fab-7: it blocks crosstalk but does not support bypass. Mutation of the Mcp Pita site disrupts blocking activity and also eliminates dCTCF binding. In contrast, mutation of the Mcp dCTCF site does not affect Pita binding, and this mutant boundary retains partial function.
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Affiliation(s)
- Olga Kyrchanova
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Nikolay Zolotarev
- Group of Molecular Organization of Genome, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Vladic Mogila
- Laboratory of Regulation of Gene Expression in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Oksana Maksimenko
- Group of Molecular Organization of Genome, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Paul Schedl
- Laboratory of Regulation of Gene Expression in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia .,Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Pavel Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
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50
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Three-Dimensional Genome Organization and Function in Drosophila. Genetics 2017; 205:5-24. [PMID: 28049701 PMCID: PMC5223523 DOI: 10.1534/genetics.115.185132] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 10/15/2016] [Indexed: 12/18/2022] Open
Abstract
Understanding how the metazoan genome is used during development and cell differentiation is one of the major challenges in the postgenomic era. Early studies in Drosophila suggested that three-dimensional (3D) chromosome organization plays important regulatory roles in this process and recent technological advances started to reveal connections at the molecular level. Here we will consider general features of the architectural organization of the Drosophila genome, providing historical perspective and insights from recent work. We will compare the linear and spatial segmentation of the fly genome and focus on the two key regulators of genome architecture: insulator components and Polycomb group proteins. With its unique set of genetic tools and a compact, well annotated genome, Drosophila is poised to remain a model system of choice for rapid progress in understanding principles of genome organization and to serve as a proving ground for development of 3D genome-engineering techniques.
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