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Messina O, Raynal F, Gurgo J, Fiche JB, Pancaldi V, Nollmann M. 3D chromatin interactions involving Drosophila insulators are infrequent but preferential and arise before TADs and transcription. Nat Commun 2023; 14:6678. [PMID: 37865700 PMCID: PMC10590426 DOI: 10.1038/s41467-023-42485-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 10/12/2023] [Indexed: 10/23/2023] Open
Abstract
In mammals, insulators contribute to the regulation of loop extrusion to organize chromatin into topologically associating domains. In Drosophila the role of insulators in 3D genome organization is, however, under current debate. Here, we addressed this question by combining bioinformatics analysis and multiplexed chromatin imaging. We describe a class of Drosophila insulators enriched at regions forming preferential chromatin interactions genome-wide. Notably, most of these 3D interactions do not involve TAD borders. Multiplexed imaging shows that these interactions occur infrequently, and only rarely involve multiple genomic regions coalescing together in space in single cells. Finally, we show that non-border preferential 3D interactions enriched in this class of insulators are present before TADs and transcription during Drosophila development. Our results are inconsistent with insulators forming stable hubs in single cells, and instead suggest that they fine-tune existing 3D chromatin interactions, providing an additional regulatory layer for transcriptional regulation.
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Affiliation(s)
- Olivier Messina
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France
| | - Flavien Raynal
- CRCT, Université de Toulouse, Inserm, CNRS, Université Toulouse III-Paul Sabatier, Centre de Recherches en Cancérologie de Toulouse, Toulouse, France
| | - Julian Gurgo
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France
| | - Jean-Bernard Fiche
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France
| | - Vera Pancaldi
- CRCT, Université de Toulouse, Inserm, CNRS, Université Toulouse III-Paul Sabatier, Centre de Recherches en Cancérologie de Toulouse, Toulouse, France.
- Barcelona Supercomputing Center, Barcelona, Spain.
| | - Marcelo Nollmann
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France.
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2
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Nollmann M, Bennabi I, Götz M, Gregor T. The Impact of Space and Time on the Functional Output of the Genome. Cold Spring Harb Perspect Biol 2022; 14:a040378. [PMID: 34230036 PMCID: PMC8733053 DOI: 10.1101/cshperspect.a040378] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Over the past two decades, it has become clear that the multiscale spatial and temporal organization of the genome has important implications for nuclear function. This review centers on insights gained from recent advances in light microscopy on our understanding of transcription. We discuss spatial and temporal aspects that shape nuclear order and their consequences on regulatory components, focusing on genomic scales most relevant to function. The emerging picture is that spatiotemporal constraints increase the complexity in transcriptional regulation, highlighting new challenges, such as uncertainty about how information travels from molecular factors through the genome and space to generate a functional output.
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Affiliation(s)
- Marcelo Nollmann
- Centre de Biologie Structurale, CNRS UMR5048, INSERM U1054, Univ Montpellier, 34090 Montpellier, France
| | - Isma Bennabi
- Department of Stem Cell and Developmental Biology, CNRS UMR3738, Institut Pasteur, 75015 Paris, France
| | - Markus Götz
- Centre de Biologie Structurale, CNRS UMR5048, INSERM U1054, Univ Montpellier, 34090 Montpellier, France
| | - Thomas Gregor
- Department of Stem Cell and Developmental Biology, CNRS UMR3738, Institut Pasteur, 75015 Paris, France
- Joseph Henry Laboratory of Physics & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, USA
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3
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Heurteau A, Perrois C, Depierre D, Fosseprez O, Humbert J, Schaak S, Cuvier O. Insulator-based loops mediate the spreading of H3K27me3 over distant micro-domains repressing euchromatin genes. Genome Biol 2020; 21:193. [PMID: 32746892 PMCID: PMC7397589 DOI: 10.1186/s13059-020-02106-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 07/14/2020] [Indexed: 12/16/2022] Open
Abstract
Abstract
Background
Chromosomes are subdivided spatially to delimit long-range interactions into topologically associating domains (TADs). TADs are often flanked by chromatin insulators and transcription units that may participate in such demarcation. Remarkably, single-cell Drosophila TAD units correspond to dynamic heterochromatin nano-compartments that can self-assemble. The influence of insulators on such dynamic compartmentalization remains unclear. Moreover, to what extent heterochromatin domains are fully compartmentalized away from active genes remains unclear from Drosophila to human.
Results
Here, we identify H3K27me3 micro-domains genome-wide in Drosophila, which are attributed to the three-dimensional spreading of heterochromatin marks into euchromatin. Whereas depletion of insulator proteins increases H3K27me3 spreading locally, across heterochromatin borders, it concomitantly decreases H3K27me3 levels at distant micro-domains discrete sites. Quantifying long-range interactions suggests that random interactions between heterochromatin TADs and neighbor euchromatin cannot predict the presence of micro-domains, arguing against the hypothesis that they reflect defects in self-folding or in insulating repressive TADs. Rather, micro-domains are predicted by specific long-range interactions with the TAD borders bound by insulator proteins and co-factors required for looping. Accordingly, H3K27me3 spreading to distant sites is impaired by insulator mutants that compromise recruitment of looping co-factors. Both depletions and insulator mutants significantly reduce H3K27me3 micro-domains, deregulating the flanking genes.
Conclusions
Our data highlight a new regulatory mode of H3K27me3 by insulator-based long-range interactions controlling distant euchromatic genes.
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Affiliation(s)
- Alexandre Heurteau
- Chromatin Dynamics and Cell Proliferation, Center of Integrative Biology (CBI), Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université Fédérale Paul Sabatier de Toulouse (UPS), F-31000, Toulouse, France
| | - Charlène Perrois
- Chromatin Dynamics and Cell Proliferation, Center of Integrative Biology (CBI), Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université Fédérale Paul Sabatier de Toulouse (UPS), F-31000, Toulouse, France
| | - David Depierre
- Chromatin Dynamics and Cell Proliferation, Center of Integrative Biology (CBI), Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université Fédérale Paul Sabatier de Toulouse (UPS), F-31000, Toulouse, France
| | - Olivier Fosseprez
- Chromatin Dynamics and Cell Proliferation, Center of Integrative Biology (CBI), Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université Fédérale Paul Sabatier de Toulouse (UPS), F-31000, Toulouse, France
| | - Jonathan Humbert
- Chromatin Dynamics and Cell Proliferation, Center of Integrative Biology (CBI), Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université Fédérale Paul Sabatier de Toulouse (UPS), F-31000, Toulouse, France
- St. Patrick Research Group in Basic Oncology, Laval University Cancer Research Center, Centre Hospitalier Universitaire de Québec City, Quebec, QC, G1R 3S3, Canada
| | - Stéphane Schaak
- Chromatin Dynamics and Cell Proliferation, Center of Integrative Biology (CBI), Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université Fédérale Paul Sabatier de Toulouse (UPS), F-31000, Toulouse, France
| | - Olivier Cuvier
- Chromatin Dynamics and Cell Proliferation, Center of Integrative Biology (CBI), Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université Fédérale Paul Sabatier de Toulouse (UPS), F-31000, Toulouse, France.
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4
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The Integrity of piRNA Clusters is Abolished by Insulators in the Drosophila Germline. Genes (Basel) 2019; 10:genes10030209. [PMID: 30862119 PMCID: PMC6471301 DOI: 10.3390/genes10030209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 02/27/2019] [Accepted: 03/06/2019] [Indexed: 12/13/2022] Open
Abstract
Piwi-interacting RNAs (piRNAs) control transposable element (TE) activity in the germline. piRNAs are produced from single-stranded precursors transcribed from distinct genomic loci, enriched by TE fragments and termed piRNA clusters. The specific chromatin organization and transcriptional regulation of Drosophila germline-specific piRNA clusters ensure transcription and processing of piRNA precursors. TEs harbour various regulatory elements that could affect piRNA cluster integrity. One of such elements is the suppressor-of-hairy-wing (Su(Hw))-mediated insulator, which is harboured in the retrotransposon gypsy. To understand how insulators contribute to piRNA cluster activity, we studied the effects of transgenes containing gypsy insulators on local organization of endogenous piRNA clusters. We show that transgene insertions interfere with piRNA precursor transcription, small RNA production and the formation of piRNA cluster-specific chromatin, a hallmark of which is Rhino, the germline homolog of the heterochromatin protein 1 (HP1). The mutations of Su(Hw) restored the integrity of piRNA clusters in transgenic strains. Surprisingly, Su(Hw) depletion enhanced the production of piRNAs by the domesticated telomeric retrotransposon TART, indicating that Su(Hw)-dependent elements protect TART transcripts from piRNA processing machinery in telomeres. A genome-wide analysis revealed that Su(Hw)-binding sites are depleted in endogenous germline piRNA clusters, suggesting that their functional integrity is under strict evolutionary constraints.
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Dense neural networks for predicting chromatin conformation. BMC Bioinformatics 2018; 19:372. [PMID: 30314429 PMCID: PMC6186068 DOI: 10.1186/s12859-018-2286-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/16/2018] [Indexed: 12/12/2022] Open
Abstract
Background DNA inside eukaryotic cells wraps around histones to form the 11nm chromatin fiber that can further fold into higher-order DNA loops, which may depend on the binding of architectural factors. Predicting how the DNA will fold given a distribution of bound factors, here viewed as a type of sequence, is currently an unsolved problem and several heterogeneous polymer models have shown that many features of the measured structure can be reproduced from simulations. However a model that determines the optimal connection between sequence and structure and that can rapidly assess the effects of varying either one is still lacking. Results Here we train a dense neural network to solve for the local folding of chromatin, connecting structure, represented as a contact map, to a sequence of bound chromatin factors. The network includes a convolutional filter that compresses the large number of bound chromatin factors into a single 1D sequence representation that is optimized for predicting structure. We also train a network to solve the inverse problem, namely given only structural information in the form of a contact map, predict the likely sequence of chromatin states that generated it. Conclusions By carrying out sensitivity analysis on both networks, we are able to highlight the importance of chromatin contexts and neighborhoods for regulating long-range contacts, along with critical alterations that affect contact formation. Our analysis shows that the networks have learned physical insights that are informative and intuitive about this complex polymer problem. Electronic supplementary material The online version of this article (10.1186/s12859-018-2286-z) contains supplementary material, which is available to authorized users.
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Mitra S, Biswas A, Narlikar L. DIVERSITY in binding, regulation, and evolution revealed from high-throughput ChIP. PLoS Comput Biol 2018; 14:e1006090. [PMID: 29684008 PMCID: PMC5933800 DOI: 10.1371/journal.pcbi.1006090] [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: 09/07/2017] [Revised: 05/03/2018] [Accepted: 03/14/2018] [Indexed: 12/27/2022] Open
Abstract
Genome-wide in vivo protein-DNA interactions are routinely mapped using high-throughput chromatin immunoprecipitation (ChIP). ChIP-reported regions are typically investigated for enriched sequence-motifs, which are likely to model the DNA-binding specificity of the profiled protein and/or of co-occurring proteins. However, simple enrichment analyses can miss insights into the binding-activity of the protein. Note that ChIP reports regions making direct contact with the protein as well as those binding through intermediaries. For example, consider a ChIP experiment targeting protein X, which binds DNA at its cognate sites, but simultaneously interacts with four other proteins. Each of these proteins also binds to its own specific cognate sites along distant parts of the genome, a scenario consistent with the current view of transcriptional hubs and chromatin loops. Since ChIP will pull down all X-associated regions, the final reported data will be a union of five distinct sets of regions, each containing binding sites of one of the five proteins, respectively. Characterizing all five different motifs and the corresponding sets is important to interpret the ChIP experiment and ultimately, the role of X in regulation. We present diversity which attempts exactly this: it partitions the data so that each partition can be characterized with its own de novo motif. Diversity uses a Bayesian approach to identify the optimal number of motifs and the associated partitions, which together explain the entire dataset. This is in contrast to standard motif finders, which report motifs individually enriched in the data, but do not necessarily explain all reported regions. We show that the different motifs and associated regions identified by diversity give insights into the various complexes that may be forming along the chromatin, something that has so far not been attempted from ChIP data. Webserver at http://diversity.ncl.res.in/; standalone (Mac OS X/Linux) from https://github.com/NarlikarLab/DIVERSITY/releases/tag/v1.0.0. A high-throughput chromatin immunoprecipitation (ChIP) experiment identifies genomic regions bound by a protein in vivo. Current motif-discovery approaches seek an enriched motif signature in the reported regions, which they can attribute to the protein’s binding preferences. However, Diversity models the fact that since a ChIP experiment pulls down regions participating in all complexes involving the profiled protein, the reported regions are in all likelihood, a collection of different types of protein-DNA contacts. Diversity asks a different question: what sequence component caused a specific region to be reported in a ChIP experiment? The answer, in combination with additional data such as sequence conservation, SNPs, chromatin structure, downstream gene-expression, etc. can yield insights into the diverse regulatory mechanisms at play. The added benefits of a webserver and a standalone parallel version make diversity a practical tool for discovering new biology from ChIP experiments.
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Affiliation(s)
- Sneha Mitra
- Department of Chemical Engineering, CSIR-National Chemical Laboratory, Pune, India
| | - Anushua Biswas
- Department of Chemical Engineering, CSIR-National Chemical Laboratory, Pune, India
| | - Leelavati Narlikar
- Department of Chemical Engineering, CSIR-National Chemical Laboratory, Pune, India
- * E-mail:
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7
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Farré P, Emberly E. A maximum-entropy model for predicting chromatin contacts. PLoS Comput Biol 2018; 14:e1005956. [PMID: 29401453 PMCID: PMC5814105 DOI: 10.1371/journal.pcbi.1005956] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 02/15/2018] [Accepted: 01/04/2018] [Indexed: 11/19/2022] Open
Abstract
The packaging of DNA inside a nucleus shows complex structure stabilized by a host of DNA-bound factors. Both the distribution of these factors and the contacts between different genomic locations of the DNA can now be measured on a genome-wide scale. This has advanced the development of models aimed at predicting the conformation of DNA given only the locations of bound factors-the chromatin folding problem. Here we present a maximum-entropy model that is able to predict a contact map representation of structure given a sequence of bound factors. Non-local effects due to the sequence neighborhood around contacting sites are found to be important for making accurate predictions. Lastly, we show that the model can be used to infer a sequence of bound factors given only a measurement of structure. This opens up the possibility for efficiently predicting sequence regions that may play a role in generating cell-type specific structural differences.
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Affiliation(s)
- Pau Farré
- Department of Physics, Simon Fraser University, Burnaby, BC V5A1S6, Canada
| | - Eldon Emberly
- Department of Physics, Simon Fraser University, Burnaby, BC V5A1S6, Canada
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8
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Romanova N, Noll T. Engineered and Natural Promoters and Chromatin-Modifying Elements for Recombinant Protein Expression in CHO Cells. Biotechnol J 2017; 13:e1700232. [DOI: 10.1002/biot.201700232] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 11/07/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Nadiya Romanova
- Cell Culture Technology; Faculty of Technology; Bielefeld University; Germany
| | - Thomas Noll
- Cell Culture Technology; Faculty of Technology; Bielefeld University; Germany
- Bielefeld University; Center for Biotechnology (CeBiTec); Germany
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9
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Tue NT, Yoshioka Y, Mizoguchi M, Yoshida H, Zurita M, Yamaguchi M. DREF plays multiple roles during Drosophila development. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1860:705-712. [PMID: 28363744 DOI: 10.1016/j.bbagrm.2017.03.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/27/2017] [Accepted: 03/27/2017] [Indexed: 12/31/2022]
Abstract
DREF was originally identified as a transcription factor that coordinately regulates the expression of DNA replication- and proliferation-related genes in Drosophila. Subsequent studies demonstrated that DREF is involved in tumor suppressor pathways including p53 and Hippo signaling. DREF also regulates the expression of genes encoding components of the JNK and EGFR pathways during Drosophila development. DREF itself is under the control of the TOR pathway during cell and tissue growth responding to nutrition. Recent studies revealed that DREF plays a role in chromatin organization including insulator function, chromatin remodeling, and telomere maintenance. DREF is also involved in the regulation of genes related to mitochondrial biogenesis, linking it to cellular proliferation. Thus, DREF is now emerging as not only a transcription factor, but also a multi-functional protein. In this review, we summarize current advances in studies on the novel functions of Drosophila DREF.
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Affiliation(s)
- Nguyen Trong Tue
- Gene-Protein Research Center, Hanoi Medical University, Hanoi, Vietnam
| | - Yasuhide Yoshioka
- Faculty of Science and Engineering, Setsunan University, Osaka, Japan
| | - Megumi Mizoguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; The Center for Advanced Insect Research, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Mario Zurita
- Departamento de Genética del Desarrollo Y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, 62250 Cuernavaca, Mor., Mexico
| | - Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; The Center for Advanced Insect Research, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
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Chetverina D, Fujioka M, Erokhin M, Georgiev P, Jaynes JB, Schedl P. Boundaries of loop domains (insulators): Determinants of chromosome form and function in multicellular eukaryotes. Bioessays 2017; 39. [PMID: 28133765 DOI: 10.1002/bies.201600233] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Chromosomes in multicellular animals are subdivided into a series of looped domains. In addition to being the underlying principle for organizing the chromatin fiber, looping is critical for processes ranging from gene regulation to recombination and repair. The subdivision of chromosomes into looped domains depends upon a special class of architectural elements called boundaries or insulators. These elements are distributed throughout the genome and are ubiquitous building blocks of chromosomes. In this review, we focus on features of boundaries that are critical in determining the topology of the looped domains and their genetic properties. We highlight the properties of fly boundaries that are likely to have an important bearing on the organization of looped domains in vertebrates, and discuss the functional consequences of the observed similarities and differences.
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Affiliation(s)
- Darya Chetverina
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Miki Fujioka
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Maksim Erokhin
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Pavel Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - James B Jaynes
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Paul Schedl
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.,Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
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11
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Prostate Cancer Patients-Negative Biopsy Controls Discrimination by Untargeted Metabolomics Analysis of Urine by LC-QTOF: Upstream Information on Other Omics. Sci Rep 2016; 6:38243. [PMID: 27910903 PMCID: PMC5133625 DOI: 10.1038/srep38243] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/04/2016] [Indexed: 01/06/2023] Open
Abstract
The existing clinical biomarkers for prostate cancer (PCa) diagnosis are far from ideal (e.g., the prostate specific antigen (PSA) serum level suffers from lack of specificity, providing frequent false positives leading to over-diagnosis). A key step in the search for minimum invasive tests to complement or replace PSA should be supported on the changes experienced by the biochemical pathways in PCa patients as compared to negative biopsy control individuals. In this research a comprehensive global analysis by LC–QTOF was applied to urine from 62 patients with a clinically significant PCa and 42 healthy individuals, both groups confirmed by biopsy. An unpaired t-test (p-value < 0.05) provided 28 significant metabolites tentatively identified in urine, used to develop a partial least squares discriminant analysis (PLS-DA) model characterized by 88.4 and 92.9% of sensitivity and specificity, respectively. Among the 28 significant metabolites 27 were present at lower concentrations in PCa patients than in control individuals, while only one reported higher concentrations in PCa patients. The connection among the biochemical pathways in which they are involved (DNA methylation, epigenetic marks on histones and RNA cap methylation) could explain the concentration changes with PCa and supports, once again, the role of metabolomics in upstream processes.
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12
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Shachar S, Voss TC, Pegoraro G, Sciascia N, Misteli T. Identification of Gene Positioning Factors Using High-Throughput Imaging Mapping. Cell 2016; 162:911-23. [PMID: 26276637 DOI: 10.1016/j.cell.2015.07.035] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 06/08/2015] [Accepted: 06/27/2015] [Indexed: 10/23/2022]
Abstract
Genomes are arranged non-randomly in the 3D space of the cell nucleus. Here, we have developed HIPMap, a high-precision, high-throughput, automated fluorescent in situ hybridization imaging pipeline, for mapping of the spatial location of genome regions at large scale. High-throughput imaging position mapping (HIPMap) enabled an unbiased siRNA screen for factors involved in genome organization in human cells. We identify 50 cellular factors required for proper positioning of a set of functionally diverse genomic loci. Positioning factors include chromatin remodelers, histone modifiers, and nuclear envelope and pore proteins. Components of the replication and post-replication chromatin re-assembly machinery are prominently represented among positioning factors, and timely progression of cells through replication, but not mitosis, is required for correct gene positioning. Our results establish a method for the large-scale mapping of genome locations and have led to the identification of a compendium of cellular factors involved in spatial genome organization.
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Affiliation(s)
- Sigal Shachar
- National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Ty C Voss
- High Throughput Imaging Facility (HiTIF), National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Gianluca Pegoraro
- High Throughput Imaging Facility (HiTIF), National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | | | - Tom Misteli
- National Cancer Institute, NIH, Bethesda, MD 20892, USA.
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13
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Ali T, Renkawitz R, Bartkuhn M. Insulators and domains of gene expression. Curr Opin Genet Dev 2016; 37:17-26. [PMID: 26802288 DOI: 10.1016/j.gde.2015.11.009] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 11/20/2015] [Accepted: 11/25/2015] [Indexed: 01/07/2023]
Abstract
The genomic organization into active and inactive chromatin domains imposes specific requirements for having domain boundaries to prohibit interference between the opposing activities of neighbouring domains. These boundaries provide an insulator function by binding architectural proteins that mediate long-range interactions. Among these, CTCF plays a prominent role in establishing chromatin loops (between pairs of CTCF binding sites) through recruiting cohesin. CTCF-mediated long-range interactions are integral for a multitude of topological features of interphase chromatin, such as the formation of topologically associated domains, domain insulation, enhancer blocking and even enhancer function.
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Affiliation(s)
- Tamer Ali
- Institute for Genetics, Justus-Liebig-University, Heinrich-Buff-Ring 58, D35392 Giessen, Germany
| | - Rainer Renkawitz
- Institute for Genetics, Justus-Liebig-University, Heinrich-Buff-Ring 58, D35392 Giessen, Germany.
| | - Marek Bartkuhn
- Institute for Genetics, Justus-Liebig-University, Heinrich-Buff-Ring 58, D35392 Giessen, Germany
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14
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Plevock KM, Galletta BJ, Slep KC, Rusan NM. Newly Characterized Region of CP190 Associates with Microtubules and Mediates Proper Spindle Morphology in Drosophila Stem Cells. PLoS One 2015; 10:e0144174. [PMID: 26649574 PMCID: PMC4674064 DOI: 10.1371/journal.pone.0144174] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 11/13/2015] [Indexed: 11/27/2022] Open
Abstract
CP190 is a large, multi-domain protein, first identified as a centrosome protein with oscillatory localization over the course of the cell cycle. During interphase it has a well-established role within the nucleus as a chromatin insulator. Upon nuclear envelope breakdown, there is a striking redistribution of CP190 to centrosomes and the mitotic spindle, in addition to the population at chromosomes. Here, we investigate CP190 in detail by performing domain analysis in cultured Drosophila S2 cells combined with protein structure determination by X-ray crystallography, in vitro biochemical characterization, and in vivo fixed and live imaging of cp190 mutant flies. Our analysis of CP190 identifies a novel N-terminal centrosome and microtubule (MT) targeting region, sufficient for spindle localization. This region consists of a highly conserved BTB domain and a linker region that serves as the MT binding domain. We present the 2.5 Å resolution structure of the CP190 N-terminal 126 amino acids, which adopts a canonical BTB domain fold and exists as a stable dimer in solution. The ability of the linker region to robustly localize to MTs requires BTB domain-mediated dimerization. Deletion of the linker region using CRISPR significantly alters spindle morphology and leads to DNA segregation errors in the developing Drosophila brain neuroblasts. Collectively, we highlight a multivalent MT-binding architecture in CP190, which confers distinct subcellular cytoskeletal localization and function during mitosis.
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Affiliation(s)
- Karen M. Plevock
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, 20892, United State of America
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, 27599, United States of America
| | - Brian J. Galletta
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, 20892, United State of America
| | - Kevin C. Slep
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, 27599, United States of America
- * E-mail: (NMR); (KCS)
| | - Nasser M. Rusan
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, 20892, United State of America
- * E-mail: (NMR); (KCS)
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15
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Zielke T, Glotov A, Saumweber H. High-resolution in situ hybridization analysis on the chromosomal interval 61C7-61C8 of Drosophila melanogaster reveals interbands as open chromatin domains. Chromosoma 2015; 125:423-35. [PMID: 26520107 DOI: 10.1007/s00412-015-0554-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 10/22/2022]
Abstract
Eukaryotic chromatin is organized in contiguous domains that differ in protein binding, histone modifications, transcriptional activity, and in their degree of compaction. Genome-wide comparisons suggest that, overall, the chromatin organization is similar in different cells within an organism. Here, we compare the structure and activity of the 61C7-61C8 interval in polytene and diploid cells of Drosophila. By in situ hybridization on polytene chromosomes combined with high-resolution microscopy, we mapped the boundaries of the 61C7-8 interband and of the 61C7 and C8 band regions, respectively. Our results demonstrate that the 61C7-8 interband is significantly larger than estimated previously. This interband extends over 20 kbp and is in the range of the flanking band domains. It contains several active genes and therefore can be considered as an open chromatin domain. Comparing the 61C7-8 structure of Drosophila S2 cells and polytene salivary gland cells by ChIP for chromatin protein binding and histone modifications, we observe a highly consistent domain structure for the proximal 13 kbp of the domain in both cell types. However, the distal 7 kbp of the open domain differs in protein binding and histone modification between both tissues. The domain contains four protein-coding genes in the proximal part and two noncoding transcripts in the distal part. The differential transcriptional activity of one of the noncoding transcripts correlates with the observed differences in the chromatin structure between both tissues. The significance of our findings for the organization and structure of open chromatin domains will be discussed.
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Affiliation(s)
- Thomas Zielke
- Institute of Biology, Cytogenetics Group, Humboldt University Berlin, Chausseestr. 117, 10115, Berlin, Germany
| | - Alexander Glotov
- Institute of Biology, Cytogenetics Group, Humboldt University Berlin, Chausseestr. 117, 10115, Berlin, Germany
| | - Harald Saumweber
- Institute of Biology, Cytogenetics Group, Humboldt University Berlin, Chausseestr. 117, 10115, Berlin, Germany. .,Institut für Biologie-Zytogenetik, Humboldt Universität zu Berlin, Chausseestr. 117, 10115, Berlin, Germany.
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16
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Fraser J, Williamson I, Bickmore WA, Dostie J. An Overview of Genome Organization and How We Got There: from FISH to Hi-C. Microbiol Mol Biol Rev 2015; 79:347-72. [PMID: 26223848 PMCID: PMC4517094 DOI: 10.1128/mmbr.00006-15] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In humans, nearly two meters of genomic material must be folded to fit inside each micrometer-scale cell nucleus while remaining accessible for gene transcription, DNA replication, and DNA repair. This fact highlights the need for mechanisms governing genome organization during any activity and to maintain the physical organization of chromosomes at all times. Insight into the functions and three-dimensional structures of genomes comes mostly from the application of visual techniques such as fluorescence in situ hybridization (FISH) and molecular approaches including chromosome conformation capture (3C) technologies. Recent developments in both types of approaches now offer the possibility of exploring the folded state of an entire genome and maybe even the identification of how complex molecular machines govern its shape. In this review, we present key methodologies used to study genome organization and discuss what they reveal about chromosome conformation as it relates to transcription regulation across genomic scales in mammals.
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Affiliation(s)
- James Fraser
- Department of Biochemistry, and Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
| | - Iain Williamson
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Wendy A Bickmore
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Josée Dostie
- Department of Biochemistry, and Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
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17
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Functional Requirements for Fab-7 Boundary Activity in the Bithorax Complex. Mol Cell Biol 2015; 35:3739-52. [PMID: 26303531 DOI: 10.1128/mcb.00456-15] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 08/17/2015] [Indexed: 12/23/2022] Open
Abstract
Chromatin boundaries are architectural elements that determine the three-dimensional folding of the chromatin fiber and organize the chromosome into independent units of genetic activity. The Fab-7 boundary from the Drosophila bithorax complex (BX-C) is required for the parasegment-specific expression of the Abd-B gene. We have used a replacement strategy to identify sequences that are necessary and sufficient for Fab-7 boundary function in the BX-C. Fab-7 boundary activity is known to depend on factors that are stage specific, and we describe a novel ∼700-kDa complex, the late boundary complex (LBC), that binds to Fab-7 sequences that have insulator functions in late embryos and adults. We show that the LBC is enriched in nuclear extracts from late, but not early, embryos and that it contains three insulator proteins, GAF, Mod(mdg4), and E(y)2. Its DNA binding properties are unusual in that it requires a minimal sequence of >65 bp; however, other than a GAGA motif, the three Fab-7 LBC recognition elements display few sequence similarities. Finally, we show that mutations which abrogate LBC binding in vitro inactivate the Fab-7 boundary in the BX-C.
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18
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Razin SV, Gavrilov AA, Ulyanov SV. Transcription-controlling regulatory elements of the eukaryotic genome. Mol Biol 2015. [DOI: 10.1134/s0026893315020119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Dai Q, Ren A, Westholm JO, Duan H, Patel DJ, Lai EC. Common and distinct DNA-binding and regulatory activities of the BEN-solo transcription factor family. Genes Dev 2015; 29:48-62. [PMID: 25561495 PMCID: PMC4281564 DOI: 10.1101/gad.252122.114] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The BEN domain is recognized as a new class of conserved DNA-binding domain. The fly genome encodes three proteins that bear only a single BEN domain (“BEN-solo” factors); namely, Insensitive (Insv), Bsg25A (Elba1), and CG9883 (Elba2). Dai et al. identify both distinct and overlapping functional properties of these three Drosophila BEN-solo proteins, introducing unexpected complexity in their contributions to gene regulation and development. Recently, the BEN (BANP, E5R, and NAC1) domain was recognized as a new class of conserved DNA-binding domain. The fly genome encodes three proteins that bear only a single BEN domain (“BEN-solo” factors); namely, Insensitive (Insv), Bsg25A (Elba1), and CG9883 (Elba2). Insv homodimers preferentially bind CCAATTGG palindromes throughout the genome to mediate transcriptional repression, whereas Bsg25A and Elba2 heterotrimerize with their obligate adaptor, Elba3 (i.e., the ELBA complex), to recognize a CCAATAAG motif in the Fab-7 insulator. While these data suggest distinct DNA-binding properties of BEN-solo proteins, we performed reporter assays that indicate that both Bsg25A and Elba2 can individually recognize Insv consensus sites efficiently. We confirmed this by solving the structure of Bsg25A complexed to the Insv site, which showed that key aspects of the BEN:DNA recognition strategy are similar between these proteins. We next show that both Insv and ELBA proteins are competent to mediate transcriptional repression via Insv consensus sequences but that the ELBA complex appears to be selective for the ELBA site. Reciprocally, genome-wide analysis reveals that Insv exhibits significant cobinding to class I insulator elements, indicating that it may also contribute to insulator function. Indeed, we observed abundant Insv binding within the Hox complexes with substantial overlaps with class I insulators, many of which bear Insv consensus sites. Moreover, Insv coimmunoprecipitates with the class I insulator factor CP190. Finally, we observed that Insv harbors exclusive activity among fly BEN-solo factors with respect to regulation of Notch-mediated cell fate choices in the peripheral nervous system. This in vivo activity is recapitulated by BEND6, a mammalian BEN-solo factor that conserves the Notch corepressor function of Insv but not its capacity to bind Insv consensus sites. Altogether, our data define an array of common and distinct biochemical and functional properties of this new family of transcription factors.
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Affiliation(s)
- Qi Dai
- Department of Developmental Biology
| | - Aiming Ren
- Department of Structural Biology, Sloan-Kettering Institute New York, New York 10065, USA
| | | | | | - Dinshaw J Patel
- Department of Structural Biology, Sloan-Kettering Institute New York, New York 10065, USA
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20
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Kunes P, Mandak J, Holubcova Z, Kolackova M, Krejsek J. Actual position of interleukin(IL)-33 in atherosclerosis and heart failure: Great Expectations or En attendant Godot? Perfusion 2014; 30:356-74. [DOI: 10.1177/0267659114562269] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Atherosclerosis has been recognized as an inflammatory/autoimmune disease. The long-standing low-grade inflammation which fuels its development is primarily focused on the components of the vessel wall. Originally, inflammation in atherogenesis was supposed to be driven by the pro-inflammatory Th1 cellular and cytokine immune response. On the basis of accumulating evidence, this view has been re-evaluated to include the Th17/Th1 axis which is shared by most diseases of sterile inflammation. The anti-inflammatory Th2 cellular and cytokine immune response is initiated concomitantly with the former two, the latter dampening their harmful reactions which culminate in full-blown atherosclerosis. Interleukin-33, a novel member of the IL-1 cytokine superfamily, was suggested to take part in the anti-atherogenic response by mediating the Th1-to-Th2 switch of the immune reactions. However, IL-33 is a multifaceted mediator with both pro- and anti-inflammatory activities, also called a “dual factor” or a “Janus face” interleukin. IL-33 occurs both in an extracellular (cytokine-like) and in a nuclear-bound (transcription factor-like) form, each of them performing distinct activities of their own. This review article presents the latest data relevant to IL-33’s role in atherosclerosis and cardiac diseases as perceived by a cardiologist and a cardiac surgeon.
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Affiliation(s)
- P Kunes
- Department of Cardiac Surgery, Charles University in Prague, Faculty of Medicine and University Hospital in Hradec Kralove, Czech Republic
| | - J Mandak
- Department of Cardiac Surgery, Charles University in Prague, Faculty of Medicine and University Hospital in Hradec Kralove, Czech Republic
| | - Z Holubcova
- Department of Cardiac Surgery, Charles University in Prague, Faculty of Medicine and University Hospital in Hradec Kralove, Czech Republic
| | - M Kolackova
- Department of Clinical Immunology and Allergology, Charles University in Prague, Faculty of Medicine and University Hospital in Hradec Kralove, Czech Republic
| | - J Krejsek
- Department of Clinical Immunology and Allergology, Charles University in Prague, Faculty of Medicine and University Hospital in Hradec Kralove, Czech Republic
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21
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Vogelmann J, Le Gall A, Dejardin S, Allemand F, Gamot A, Labesse G, Cuvier O, Nègre N, Cohen-Gonsaud M, Margeat E, Nöllmann M. Chromatin insulator factors involved in long-range DNA interactions and their role in the folding of the Drosophila genome. PLoS Genet 2014; 10:e1004544. [PMID: 25165871 PMCID: PMC4148193 DOI: 10.1371/journal.pgen.1004544] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 06/17/2014] [Indexed: 11/18/2022] Open
Abstract
Chromatin insulators are genetic elements implicated in the organization of chromatin and the regulation of transcription. In Drosophila, different insulator types were characterized by their locus-specific composition of insulator proteins and co-factors. Insulators mediate specific long-range DNA contacts required for the three dimensional organization of the interphase nucleus and for transcription regulation, but the mechanisms underlying the formation of these contacts is currently unknown. Here, we investigate the molecular associations between different components of insulator complexes (BEAF32, CP190 and Chromator) by biochemical and biophysical means, and develop a novel single-molecule assay to determine what factors are necessary and essential for the formation of long-range DNA interactions. We show that BEAF32 is able to bind DNA specifically and with high affinity, but not to bridge long-range interactions (LRI). In contrast, we show that CP190 and Chromator are able to mediate LRI between specifically-bound BEAF32 nucleoprotein complexes in vitro. This ability of CP190 and Chromator to establish LRI requires specific contacts between BEAF32 and their C-terminal domains, and dimerization through their N-terminal domains. In particular, the BTB/POZ domains of CP190 form a strict homodimer, and its C-terminal domain interacts with several insulator binding proteins. We propose a general model for insulator function in which BEAF32/dCTCF/Su(HW) provide DNA specificity (first layer proteins) whereas CP190/Chromator are responsible for the physical interactions required for long-range contacts (second layer). This network of organized, multi-layer interactions could explain the different activities of insulators as chromatin barriers, enhancer blockers, and transcriptional regulators, and suggest a general mechanism for how insulators may shape the organization of higher-order chromatin during cell division.
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Affiliation(s)
- Jutta Vogelmann
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, Montpellier, France
- Institut National de la Santé et la Recherche Médicale, Unité 1054, Montpellier, France
- Universités Montpellier I et II, Montpellier, France
| | - Antoine Le Gall
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, Montpellier, France
- Institut National de la Santé et la Recherche Médicale, Unité 1054, Montpellier, France
- Universités Montpellier I et II, Montpellier, France
| | - Stephanie Dejardin
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, Montpellier, France
- Institut National de la Santé et la Recherche Médicale, Unité 1054, Montpellier, France
- Universités Montpellier I et II, Montpellier, France
| | - Frederic Allemand
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, Montpellier, France
- Institut National de la Santé et la Recherche Médicale, Unité 1054, Montpellier, France
- Universités Montpellier I et II, Montpellier, France
| | - Adrien Gamot
- Laboratoire de Biologie Moléculaire Eucaryote, CNRS and Université de Toulouse, Toulouse; France
| | - Gilles Labesse
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, Montpellier, France
- Institut National de la Santé et la Recherche Médicale, Unité 1054, Montpellier, France
- Universités Montpellier I et II, Montpellier, France
| | - Olivier Cuvier
- Laboratoire de Biologie Moléculaire Eucaryote, CNRS and Université de Toulouse, Toulouse; France
| | - Nicolas Nègre
- Laboratoire Diversité, Génomes & Interactions Microorganismes-Insectes, INRA UMR1333, Université de Montpellier 2, Montpellier, France
| | - Martin Cohen-Gonsaud
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, Montpellier, France
- Institut National de la Santé et la Recherche Médicale, Unité 1054, Montpellier, France
- Universités Montpellier I et II, Montpellier, France
| | - Emmanuel Margeat
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, Montpellier, France
- Institut National de la Santé et la Recherche Médicale, Unité 1054, Montpellier, France
- Universités Montpellier I et II, Montpellier, France
| | - Marcelo Nöllmann
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, Montpellier, France
- Institut National de la Santé et la Recherche Médicale, Unité 1054, Montpellier, France
- Universités Montpellier I et II, Montpellier, France
- * E-mail:
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22
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Lhoumaud P, Hennion M, Gamot A, Cuddapah S, Queille S, Liang J, Micas G, Morillon P, Urbach S, Bouchez O, Severac D, Emberly E, Zhao K, Cuvier O. Insulators recruit histone methyltransferase dMes4 to regulate chromatin of flanking genes. EMBO J 2014; 33:1599-613. [PMID: 24916307 DOI: 10.15252/embj.201385965] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Chromosomal domains in Drosophila are marked by the insulator-binding proteins (IBPs) dCTCF/Beaf32 and cofactors that participate in regulating long-range interactions. Chromosomal borders are further enriched in specific histone modifications, yet the role of histone modifiers and nucleosome dynamics in this context remains largely unknown. Here, we show that IBP depletion impairs nucleosome dynamics specifically at the promoters and coding sequence of genes flanked by IBP binding sites. Biochemical purification identifies the H3K36 histone methyltransferase NSD/dMes-4 as a novel IBP cofactor, which specifically co-regulates the chromatin accessibility of hundreds of genes flanked by dCTCF/Beaf32. NSD/dMes-4 presets chromatin before the recruitment of transcriptional activators including DREF that triggers Set2/Hypb-dependent H3K36 trimethylation, nucleosome positioning, and RNA splicing. Our results unveil a model for how IBPs regulate nucleosome dynamics and gene expression through NSD/dMes-4, which may regulate H3K27me3 spreading. Our data uncover how IBPs dynamically regulate chromatin organization depending on distinct cofactors.
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Affiliation(s)
- Priscillia Lhoumaud
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS Université de Toulouse (UPS), Toulouse, France
| | - Magali Hennion
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS Université de Toulouse (UPS), Toulouse, France
| | - Adrien Gamot
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS Université de Toulouse (UPS), Toulouse, France
| | - Suresh Cuddapah
- Systems Biology Center, National Heart, Lung and Blood Institute National Institutes of Health (NIH), Bethesda, MD, USA
| | - Sophie Queille
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS Université de Toulouse (UPS), Toulouse, France
| | - Jun Liang
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS Université de Toulouse (UPS), Toulouse, France
| | - Gael Micas
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS Université de Toulouse (UPS), Toulouse, France
| | - Pauline Morillon
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS Université de Toulouse (UPS), Toulouse, France
| | - Serge Urbach
- Mass-Spectrometry Facility, Institut de Génomique Fonctionnelle, Montpellier, France
| | - Olivier Bouchez
- UMR444-Laboratoire de Génétique Cellulaire & GeT-PlaGe, INRA Genotoul, Auzeville, Toulouse, France
| | - Dany Severac
- MGX-Montpellier GenomiX, Institut de Génomique Fonctionnelle, Montpellier, France
| | - Eldon Emberly
- Physics Department, Simon Fraser University (SFU), Burnaby, BC, Canada
| | - Keji Zhao
- Systems Biology Center, National Heart, Lung and Blood Institute National Institutes of Health (NIH), Bethesda, MD, USA
| | - Olivier Cuvier
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS Université de Toulouse (UPS), Toulouse, France
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23
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Liang J, Lacroix L, Gamot A, Cuddapah S, Queille S, Lhoumaud P, Lepetit P, Martin PGP, Vogelmann J, Court F, Hennion M, Micas G, Urbach S, Bouchez O, Nöllmann M, Zhao K, Emberly E, Cuvier O. Chromatin immunoprecipitation indirect peaks highlight long-range interactions of insulator proteins and Pol II pausing. Mol Cell 2014; 53:672-81. [PMID: 24486021 DOI: 10.1016/j.molcel.2013.12.029] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 08/21/2013] [Accepted: 12/27/2013] [Indexed: 11/15/2022]
Abstract
Eukaryotic chromosomes are partitioned into topologically associating domains (TADs) that are demarcated by distinct insulator-binding proteins (IBPs) in Drosophila. Whether IBPs regulate specific long-range contacts and how this may impact gene expression remains unclear. Here we identify "indirect peaks" of multiple IBPs that represent their distant sites of interactions through long-range contacts. Indirect peaks depend on protein-protein interactions among multiple IBPs and their common cofactors, including CP190, as confirmed by high-resolution analyses of long-range contacts. Mutant IBPs unable to interact with CP190 impair long-range contacts as well as the expression of hundreds of distant genes that are specifically flanked by indirect peaks. Regulation of distant genes strongly correlates with RNAPII pausing, highlighting how this key transcriptional stage may trap insulator-based long-range interactions. Our data illustrate how indirect peaks may decipher gene regulatory networks through specific long-range interactions.
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Affiliation(s)
- Jun Liang
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université de Toulouse (UPS), 31000 Toulouse, France
| | - Laurent Lacroix
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université de Toulouse (UPS), 31000 Toulouse, France
| | - Adrien Gamot
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université de Toulouse (UPS), 31000 Toulouse, France
| | - Suresh Cuddapah
- Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health (NIH), Bethesda, MD 20824, USA
| | - Sophie Queille
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université de Toulouse (UPS), 31000 Toulouse, France
| | - Priscillia Lhoumaud
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université de Toulouse (UPS), 31000 Toulouse, France
| | - Pierre Lepetit
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université de Toulouse (UPS), 31000 Toulouse, France
| | - Pascal G P Martin
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université de Toulouse (UPS), 31000 Toulouse, France; INRA, UMR444- GeT-PlaGe, Genotoul, 31326 Toulouse, France
| | - Jutta Vogelmann
- Centre de Biochimie Structurale, CNRS, 34090 Montpellier, France
| | - Franck Court
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université de Toulouse (UPS), 31000 Toulouse, France
| | - Magali Hennion
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université de Toulouse (UPS), 31000 Toulouse, France
| | - Gaël Micas
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université de Toulouse (UPS), 31000 Toulouse, France
| | - Serge Urbach
- Platform Proteomic Fonctionnelle, IGF, CNRS, 34060 Montpellier, France
| | | | - Marcelo Nöllmann
- Centre de Biochimie Structurale, CNRS, 34090 Montpellier, France
| | - Keji Zhao
- Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health (NIH), Bethesda, MD 20824, USA
| | - Eldon Emberly
- Physics Department, Simon Fraser University (SFU), Burnaby, BC V5A 1S6, Canada
| | - Olivier Cuvier
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), CNRS, Université de Toulouse (UPS), 31000 Toulouse, France.
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24
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Chetverina D, Aoki T, Erokhin M, Georgiev P, Schedl P. Making connections: insulators organize eukaryotic chromosomes into independent cis-regulatory networks. Bioessays 2013; 36:163-72. [PMID: 24277632 DOI: 10.1002/bies.201300125] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Insulators play a central role in subdividing the chromosome into a series of discrete topologically independent domains and in ensuring that enhancers and silencers contact their appropriate target genes. In this review we first discuss the general characteristics of insulator elements and their associated protein factors. A growing collection of insulator proteins have been identified including a family of proteins whose expression is developmentally regulated. We next consider several unexpected discoveries that require us to completely rethink how insulators function (and how they can best be assayed). These discoveries also require a reevaluation of how insulators might restrict or orchestrate (by preventing or promoting) interactions between regulatory elements and their target genes. We conclude by connecting these new insights into the mechanisms of insulator action to dynamic changes in the three-dimensional topology of the chromatin fiber and the generation of specific patterns of gene activity during development and differentiation.
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Affiliation(s)
- Darya Chetverina
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
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25
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Irianto J, Swift J, Martins RP, McPhail GD, Knight MM, Discher DE, Lee DA. Osmotic challenge drives rapid and reversible chromatin condensation in chondrocytes. Biophys J 2013; 104:759-69. [PMID: 23442954 DOI: 10.1016/j.bpj.2013.01.006] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Revised: 08/20/2012] [Accepted: 01/07/2013] [Indexed: 02/02/2023] Open
Abstract
Changes in extracellular osmolality have been shown to alter gene expression patterns and metabolic activity of various cell types, including chondrocytes. However, mechanisms by which physiological or pathological changes in osmolality impact chondrocyte function remain unclear. Here we use quantitative image analysis, electron microscopy, and a DNase I assay to show that hyperosmotic conditions (>400 mOsm/kg) induce chromatin condensation, while hypoosmotic conditions (100 mOsm/kg) cause decondensation. Large density changes (p < 0.001) occur over a very narrow range of physiological osmolalities, which suggests that chondrocytes likely experience chromatin condensation and decondensation during a daily loading cycle. The effect of changes in osmolality on nuclear morphology (p < 0.01) and chromatin condensation (p < 0.001) also differed between chondrocytes in monolayer culture and three-dimensional agarose, suggesting a role for cell adhesion. The relationship between condensation and osmolality was accurately modeled by a polymer gel model which, along with the rapid nature of the chromatin condensation (<20 s), reveals the basic physicochemical nature of the process. Alterations in chromatin structure are expected to influence gene expression and thereby regulate chondrocyte activity in response to osmotic changes.
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Affiliation(s)
- Jerome Irianto
- Institute of Bioengineering, School of Engineering and Material Science, Queen Mary, University of London, London, United Kingdom.
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26
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Cohen-Zinder M, Zinder-Cohen M, Karasik D, Onn I. Structural maintenance of chromosome complexes and bone development: the beginning of a wonderful relationship? BONEKEY REPORTS 2013; 2:388. [PMID: 24422108 DOI: 10.1038/bonekey.2013.122] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 06/25/2013] [Indexed: 11/09/2022]
Abstract
Bone development depends on environmental, nutritional and hormonal factors. Yet, an ordered and timed activation of genes and their associated molecular pathways are central for the growth and development of healthy bones. The correct expression of genes depends on both cis- and trans-regulatory elements. Of these, the elusive role of chromatin ultrastructure is just beginning to become appreciated. Changes in the higher-order structure of chromatin are affecting the expression of genes in response to intrinsic and environmental signals. Cohesin and condensin are members of the structural maintenance of chromosome (SMC) family of protein complexes, which mediate higher-order chromatin structure by tethering distinct regions of chromatin either inter- or intra-molecularly. In recent years, SMCs had been identified for their function in the regulation of gene expression and developmental processes, whereas malfunction of cohesin or condensin has an impact on human health. However, little is known about the specific roles of SMC complexes in bone development and their possible effect on bone health. Here, we review studies that suggest an intimate link between SMCs and bone development, as well as a plausible effect, direct or indirect, on the bone health. We describe genetic syndromes associated with SMCs with distinctive bone phenotypes and identify links between SMCs and bone-related molecular pathways. Future studies of the relationship between SMCs and bone development will reveal new understandings of both the cellular and molecular roles of SMC complexes and provide new insights into the growth and developmental processes in the bone.
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Affiliation(s)
| | - Miri Zinder-Cohen
- Faculty of Medicine in the Galilee, Bar-Ilan University , Safed, Israel
| | - David Karasik
- Faculty of Medicine in the Galilee, Bar-Ilan University , Safed, Israel ; Hebrew SeniorLife, Harvard Medical School , Boston, MA, USA
| | - Itay Onn
- Faculty of Medicine in the Galilee, Bar-Ilan University , Safed, Israel
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27
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Silva-Sousa R, Varela MD, Casacuberta E. The Putzig partners DREF, TRF2 and KEN are involved in the regulation of the Drosophila telomere retrotransposons, HeT-A and TART. Mob DNA 2013; 4:18. [PMID: 23822164 PMCID: PMC3726405 DOI: 10.1186/1759-8753-4-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 06/28/2013] [Indexed: 12/26/2022] Open
Abstract
Background Telomere maintenance in Drosophila relies on the targeted transposition of three very special non-LTR retrotransposons, HeT-A, TART, and TAHRE (HTT). The sequences of the retrotransposon array build up the telomere chromatin in this organism. We have recently reported the role of the chromosomal protein Putzig/Z4 in maintaining a proper chromatin structure at the telomere domain of Drosophila. Because the Putzig protein has been found in different cellular complexes related with cell proliferation, development, and immunity, we decided to investigate whether the previously described Putzig partners, DREF/TRF2 and KEN, could also be involved in the telomere function in this organism. Results We have found that mutant alleles for Dref/Trf2 and Ken show alterations in HeT-A and TART expression, suggesting a possible role of these protein complexes in the regulation of the telomere retrotransposons. In agreement, both HeT-A and TART contain the specific DNA binding sequences for the DREF and the KEN protein proteins. Conclusions We have identified three new negative regulators involved in the control of the expression of the telomeric retrotransposons, Dref, Trf2, and Ken. Our results offer some clues on which other chromatin-related proteins might be involved in telomere regulation and retrotransposon control.
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Affiliation(s)
- Rute Silva-Sousa
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig de la Barceloneta, 37-49, Barcelona 08003, Spain.
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28
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Khan MAF, Soto-Jimenez LM, Howe T, Streit A, Sosinsky A, Stern CD. Computational tools and resources for prediction and analysis of gene regulatory regions in the chick genome. Genesis 2013; 51:311-24. [PMID: 23355428 PMCID: PMC3664090 DOI: 10.1002/dvg.22375] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 01/16/2013] [Accepted: 01/17/2013] [Indexed: 11/07/2022]
Abstract
The discovery of cis-regulatory elements is a challenging problem in bioinformatics, owing to distal locations and context-specific roles of these elements in controlling gene regulation. Here we review the current bioinformatics methodologies and resources available for systematic discovery of cis-acting regulatory elements and conserved transcription factor binding sites in the chick genome. In addition, we propose and make available, a novel workflow using computational tools that integrate CTCF analysis to predict putative insulator elements, enhancer prediction, and TFBS analysis. To demonstrate the usefulness of this computational workflow, we then use it to analyze the locus of the gene Sox2 whose developmental expression is known to be controlled by a complex array of cis-acting regulatory elements. The workflow accurately predicts most of the experimentally verified elements along with some that have not yet been discovered. A web version of the CTCF tool, together with instructions for using the workflow can be accessed from http://toolshed.g2.bx.psu.edu/view/mkhan1980/ctcf_analysis. For local installation of the tool, relevant Perl scripts and instructions are provided in the directory named "code" in the supplementary materials.
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Affiliation(s)
- Mohsin A F Khan
- Department of Cell & Developmental Biology, University College London, London, United Kingdom
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29
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Abstract
The architecture of interphase chromosomes is important for the regulation of gene expression and genome maintenance. Chromosomes are linearly segmented into hundreds of domains with different protein compositions. Furthermore, the spatial organization of chromosomes is nonrandom and is characterized by many local and long-range contacts among genes and other sequence elements. A variety of genome-wide mapping techniques have made it possible to chart these properties at high resolution. Combined with microscopy and computational modeling, the results begin to yield a more coherent picture that integrates linear and three-dimensional (3D) views of chromosome organization in relation to gene regulation and other nuclear functions.
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30
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Transcription and Posttranscriptional Processes. Mol Biol 2013. [DOI: 10.1007/978-3-642-45361-8_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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31
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Bonetti D, Anbalagan S, Lucchini G, Clerici M, Longhese MP. Tbf1 and Vid22 promote resection and non-homologous end joining of DNA double-strand break ends. EMBO J 2012; 32:275-89. [PMID: 23222485 DOI: 10.1038/emboj.2012.327] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 11/12/2012] [Indexed: 11/09/2022] Open
Abstract
The repair of DNA double-strand breaks (DSBs) is crucial for maintaining genome stability. The Saccharomyces cerevisiae protein Tbf1, which is characterized by a Myb domain and is related to mammalian TRF1 and TRF2, has been proposed to act as a transcriptional activator. Here, we show that Tbf1 and its interacting protein Vid22 are new players in the response to DSBs. Inactivation of either TBF1 or VID22 causes hypersensitivity to DSB-inducing agents and shows strong negative interactions with mutations affecting homologous recombination. Furthermore, Tbf1 and Vid22 are recruited to an HO-induced DSB, where they promote both resection of DNA ends and repair by non-homologous end joining. Finally, inactivation of either Tbf1 or Vid22 impairs nucleosome eviction around the DSB, suggesting that these proteins promote efficient repair of the break by influencing chromatin identity in its surroundings.
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Affiliation(s)
- Diego Bonetti
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milano, Italy
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32
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Dalvai M, Bellucci L, Fleury L, Lavigne AC, Moutahir F, Bystricky K. H2A.Z-dependent crosstalk between enhancer and promoter regulates cyclin D1 expression. Oncogene 2012; 32:4243-51. [PMID: 23108396 DOI: 10.1038/onc.2012.442] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 08/09/2012] [Accepted: 08/10/2012] [Indexed: 02/08/2023]
Abstract
H2A.Z association with specific genomic loci is thought to contribute to a chromatin structure that promotes transcription activation. Acetylation of H2A.Z at promoters of oncogenes has been linked to tumorigenesis. The mechanism is unknown. Here, we show that in triple negative breast cancer cells, H2A.Z bound to the promoter of the constitutively, weakly expressed cyclin D1 oncogene (CCND1), a key regulator of cellular proliferation. Depleting the pool of H2A.Z stimulated transcription of CCND1 in the absence of its cognate transcription factor, the estrogen receptor (ER). During activation of CCND1, H2A.Z was released from the transcription start site (TSS) and downstream enhancer (enh2) sequences. Concurrently, acetylation of H2A.Z, H3 and H4 at the TSS was increased but only H2A.Z was acetylated at enh2. Acetylation of H2A.Z required the Tip60 acetyltransferase to be associated with the activated CCND1 on both TSS and enh2 sites. Depletion of Tip60 prevented CCND1 activation. Chromosome conformation capture experiments (3C) revealed specific contacts between the TSS and enh2 chromatin regions. These results suggest that release of a histone H2A.Z-mediated repression loop activates CCND1 for transcription. Our findings open new avenues for controlling and understanding aberrant gene expression associated with tumorigenesis.
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Affiliation(s)
- M Dalvai
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), University of Toulouse, Toulouse, France
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33
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Kakkar R, Hei H, Dobner S, Lee RT. Interleukin 33 as a mechanically responsive cytokine secreted by living cells. J Biol Chem 2012; 287:6941-8. [PMID: 22215666 DOI: 10.1074/jbc.m111.298703] [Citation(s) in RCA: 238] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Interleukin 33 (IL-33), a member of the Interleukin 1 cytokine family, is implicated in numerous human inflammatory diseases such as asthma, atherosclerosis, and rheumatoid arthritis. Despite its pathophysiologic importance, fundamental questions regarding the basic biology of IL-33 remain. Nuclear localization and lack of an export signal sequence are consistent with the view of IL-33 as a nuclear factor with the ability to repress RNA transcription. However, signaling via the transmembrane receptor ST2 and documented caspase-dependent inactivation have suggested IL-33 is liberated during cellular necrosis to effect paracrine signaling. We determined the subcellular localization of IL-33 and tracked its intracellular mobility and extracellular release. In contrast to published data, IL-33 localized simultaneously to nuclear euchromatin and membrane-bound cytoplasmic vesicles. Fluorescent pulse-chase fate-tracking documented dynamic nucleo-cytoplasmic flux, which was dependent on nuclear pore complex function. In murine fibroblasts in vitro and in vivo, mechanical strain induced IL-33 secretion in the absence of cellular necrosis. These data document IL-33 dynamic inter-organelle trafficking and release during biomechanical overload. As such we recharacterize IL-33 as both an inflammatory as well as mechanically responsive cytokine secreted by living cells.
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Affiliation(s)
- Rahul Kakkar
- Department of Medicine, Harvard Stem Cell Institute and the Cardiovascular Division, Brigham and Women's Hospital and Harvard Medical School, Cambridge, Massachusetts 02139, USA
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34
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Riedmann EM. Landes Highlights. RNA Biol 2012. [DOI: 10.4161/rna.9.1.19093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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