1
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Atinbayeva N, Valent I, Zenk F, Loeser E, Rauer M, Herur S, Quarato P, Pyrowolakis G, Gomez-Auli A, Mittler G, Cecere G, Erhardt S, Tiana G, Zhan Y, Iovino N. Inheritance of H3K9 methylation regulates genome architecture in Drosophila early embryos. EMBO J 2024; 43:2685-2714. [PMID: 38831123 PMCID: PMC11217351 DOI: 10.1038/s44318-024-00127-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/27/2024] [Accepted: 04/15/2024] [Indexed: 06/05/2024] Open
Abstract
Constitutive heterochromatin is essential for transcriptional silencing and genome integrity. The establishment of constitutive heterochromatin in early embryos and its role in early fruitfly development are unknown. Lysine 9 trimethylation of histone H3 (H3K9me3) and recruitment of its epigenetic reader, heterochromatin protein 1a (HP1a), are hallmarks of constitutive heterochromatin. Here, we show that H3K9me3 is transmitted from the maternal germline to the next generation. Maternally inherited H3K9me3, and the histone methyltransferases (HMT) depositing it, are required for the organization of constitutive heterochromatin: early embryos lacking H3K9 methylation display de-condensation of pericentromeric regions, centromere-centromere de-clustering, mitotic defects, and nuclear shape irregularities, resulting in embryo lethality. Unexpectedly, quantitative CUT&Tag and 4D microscopy measurements of HP1a coupled with biophysical modeling revealed that H3K9me2/3 is largely dispensable for HP1a recruitment. Instead, the main function of H3K9me2/3 at this developmental stage is to drive HP1a clustering and subsequent heterochromatin compaction. Our results show that HP1a binding to constitutive heterochromatin in the absence of H3K9me2/3 is not sufficient to promote proper embryo development and heterochromatin formation. The loss of H3K9 HMTs and H3K9 methylation alters genome organization and hinders embryonic development.
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Affiliation(s)
- Nazerke Atinbayeva
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
- Albert-Ludwigs-Universität Freiburg, Fahnenbergplatz, 79085, Freiburg im Breisgau, Germany
| | - Iris Valent
- Karlsruhe Institute of Technology (KIT), Zoological Institute, 76131, Karlsruhe, Germany
| | - Fides Zenk
- Brain Mind Institute, School of Life Sciences EPFL, SV3809, 1015, Lausanne, Switzerland
| | - Eva Loeser
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Michael Rauer
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Shwetha Herur
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Piergiuseppe Quarato
- San Raffaele Telethon Institute for Gene Therapy, IRCCS San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Giorgos Pyrowolakis
- Centre for Biological signaling studies, University of Freiburg, 79104, Freiburg im Breisgau, Germany
| | - Alejandro Gomez-Auli
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Gerhard Mittler
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Germano Cecere
- Institute Pasteur, Mechanisms of Epigenetic Inheritance, Department of Developmental and Stem Cell Biology, UMR3738, CNRS, 75724, Cedex 15, Paris, France
| | - Sylvia Erhardt
- Karlsruhe Institute of Technology (KIT), Zoological Institute, 76131, Karlsruhe, Germany
| | - Guido Tiana
- Università degli Studi di Milano and INFN, Milan, Italy
| | - Yinxiu Zhan
- Department of Experimental Oncology, European Institute of Oncology-IRCCS, Milan, Italy.
| | - Nicola Iovino
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany.
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2
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Koryakov DE. Diversity and functional specialization of H3K9-specific histone methyltransferases. Bioessays 2024; 46:e2300163. [PMID: 38058121 DOI: 10.1002/bies.202300163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/16/2023] [Accepted: 11/20/2023] [Indexed: 12/08/2023]
Abstract
Histone modifications play a critical role in the control over activities of the eukaryotic genome; among these chemical alterations, the methylation of lysine K9 in histone H3 (H3K9) is one of the most extensively studied. The number of enzymes capable of methylating H3K9 varies greatly across different organisms: in fission yeast, only one such methyltransferase is present, whereas in mammals, 10 are known. If there are several such enzymes, each of them must have some specific function, and they can interact with one another. Thus arises a complex system of interchangeability, "division of labor," and contacts with each other and with diverse proteins. Histone methyltransferases specialize in the number of methyl groups that they attach and have different intracellular localizations as well as different distributions on chromosomes. Each also shows distinct binding to different types of sequences and has a specific set of nonhistone substrates.
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Affiliation(s)
- Dmitry E Koryakov
- Lab of Molecular Cytogenetics, Institute of Molecular and Cellular Biology, Novosibirsk, Russia
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3
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Romanov SE, Shloma VV, Maksimov DA, Koryakov DE. SetDB1 and Su(var)3-9 are essential for late stages of larval development of Drosophila melanogaster. Chromosome Res 2023; 31:35. [PMID: 38099968 DOI: 10.1007/s10577-023-09743-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 10/25/2023] [Accepted: 11/02/2023] [Indexed: 12/18/2023]
Abstract
Methylation of H3K9 histone residue is a marker of gene silencing in eukaryotes. Three enzymes responsible for adding this modification - G9a, SetDB1/Egg, and Su(var)3-9 - are known in Drosophila. To understand how simultaneous mutations of SetDB1 and Su(var)3-9 may affect the fly development, appropriate combinations were obtained. Double mutants egg; Su(var)3-9 displayed pronounced embryonic lethality, slower larval growth and died before or during metamorphosis. Analysis of transcription in larval salivary glands and wing imaginal disks indicated that the effect of double mutation is tissue-specific. In salivary gland chromosomes, affected genes display low H3K9me2 enrichment and are rarely bound by SetDB1 or Su(var)3-9. We suppose that each of these enzymes directly or indirectly controls its own set of gene targets in different organs, and double mutation results in an imbalanced developmental program. This also indicates that SetDB1 and Su(var)3-9 may affect transcription via H3K9-independent mechanisms. Unexpectedly, in double and triple mutants, amount of di- and tri-methylated H3K9 is drastically reduced, but not completely absent. We hypothesize that this residual methylation implies the existence of additional H3K9-specific methyltransferase in Drosophila.
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Affiliation(s)
- Stanislav E Romanov
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, 630090, Russia
| | - Viktor V Shloma
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, 630090, Russia
| | - Daniil A Maksimov
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, 630090, Russia
| | - Dmitry E Koryakov
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, 630090, Russia.
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4
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Bloskie T, Storey KB. Epigenetics of the frozen brain: roles for lysine methylation in hypometabolism. FEBS Lett 2022; 596:2007-2020. [PMID: 35770350 DOI: 10.1002/1873-3468.14440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/10/2022] [Accepted: 06/11/2022] [Indexed: 11/08/2022]
Abstract
Wood frog (Rana sylvatica) freeze tolerance necessitates metabolic rate depression, where costly processes such as gene transcription are commonly suppressed. Epigenetic mechanisms, such as histone lysine methylation, have recently been implicated in hypometabolic states of various animals, although they are underreported in nervous tissues. In the present study, we track the expression of eight lysine methyltransferases, as well as the activity on, and abundance of putative histone products across the freeze-thaw cycle and freeze-associated sub-stresses (anoxia, dehydration) of wood frog brains. Our results suggest that hypomethylation of transcriptionally repressive H3K9 may be a key facet of metabolic recovery during the thawing of nervous tissue, which we speculate may have a positive effect on global gene transcription. Some non-histone roles for lysine methylation are also proposed.
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Affiliation(s)
- Tighe Bloskie
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Kenneth B Storey
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
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5
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Maeda R, Tachibana M. HP1 maintains protein stability of H3K9 methyltransferases and demethylases. EMBO Rep 2022; 23:e53581. [PMID: 35166421 PMCID: PMC8982598 DOI: 10.15252/embr.202153581] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 01/20/2022] [Accepted: 01/24/2022] [Indexed: 11/09/2022] Open
Abstract
Di- or tri-methylated H3K9 (H3K9me2/3) is an epigenetic mark of heterochromatin. Heterochromatin protein 1 (HP1) specifically recognizes H3K9me2/3, contributing to transcriptional suppression and spread of H3K9me2/3. Here, we demonstrate another role of HP1 in heterochromatin organization: regulation of protein stability of H3K9 methyltransferases (H3K9 MTs) and demethylases (H3K9 DMs). We show that HP1 interaction-defective mutants of H3K9 MTs, Suv39h1 and Setdb1, undergo protein degradation. We further establish mouse embryonic stem cell lines lacking all three HP1 paralogs. In the HP1-deficient cells, Suv39h1, Suv39h2, Setdb1, and G9a/GLP complex decrease at the protein level, and the enzymes are released from chromatin. HP1 mutants that cannot recognize H3K9me2/3 or form dimers cannot stabilize these enzymes, indicating that the tethering of H3K9 MTs to chromatin is critical for their protein stability. We show that HP1 also stabilizes H3K9 DMs, Jmjd1a and Jmjd1b. Our study indicates that mammalian HP1 forms a heterochromatin hub that governs protein stability of H3K9 MTs and H3K9 DMs.
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Affiliation(s)
- Ryo Maeda
- Graduate School of Frontier BiosciencesOsaka UniversityOsakaJapan,Institute of Advanced Medical SciencesTokushima UniversityTokushimaJapan
| | - Makoto Tachibana
- Graduate School of Frontier BiosciencesOsaka UniversityOsakaJapan,Institute of Advanced Medical SciencesTokushima UniversityTokushimaJapan
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6
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Guo Z, Mo Z. Regulation of endothelial cell differentiation in embryonic vascular development and its therapeutic potential in cardiovascular diseases. Life Sci 2021; 276:119406. [PMID: 33785330 DOI: 10.1016/j.lfs.2021.119406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 03/05/2021] [Accepted: 03/14/2021] [Indexed: 12/17/2022]
Abstract
During vertebrate development, the cardiovascular system begins operating earlier than any other organ in the embryo. Endothelial cell (EC) forms the inner lining of blood vessels, and its extensive proliferation and migration are requisite for vasculogenesis and angiogenesis. Many aspects of cellular biology are involved in vasculogenesis and angiogenesis, including the tip versus stalk cell specification. Recently, epigenetics has attracted growing attention in regulating embryonic vascular development and controlling EC differentiation. Some proteins that regulate chromatin structure have been shown to be directly implicated in human cardiovascular diseases. Additionally, the roles of important EC signaling such as vascular endothelial growth factor and its receptors, angiopoietin-1 and tyrosine kinase containing immunoglobulin and epidermal growth factor homology domain-2, and transforming growth factor-β in EC differentiation during embryonic vasculature development are briefly discussed in this review. Recently, the transplantation of human induced pluripotent stem cell (iPSC)-ECs are promising approaches for the treatment of ischemic cardiovascular disease including myocardial infarction. Patient-specific iPSC-derived EC is a potential new target to study differences in gene expression or response to drugs. However, clinical application of the iPSC-ECs in regenerative medicine is often limited by the challenges of maintaining cell viability and function. Therefore, novel insights into the molecular mechanisms underlying EC differentiation might provide a better understanding of embryonic vascular development and bring out more effective EC-based therapeutic strategies for cardiovascular diseases.
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Affiliation(s)
- Zi Guo
- Department of Endocrinology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhaohui Mo
- Department of Endocrinology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China.
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7
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Kalashnikova DA, Maksimov DA, Romanov SE, Laktionov PP, Koryakov DE. SetDB1 and Su(var)3-9 play non-overlapping roles in somatic cell chromosomes of Drosophila melanogaster. J Cell Sci 2021; 134:jcs.253096. [PMID: 33288549 DOI: 10.1242/jcs.253096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/30/2020] [Indexed: 11/20/2022] Open
Abstract
We explored functional roles of two H3K9-specific histone methyltransferases of Drosophila melanogaster, SetDB1 (also known as Eggless) and Su(var)3-9. Using the DamID approach, we generated the binding profile for SetDB1 in Drosophila salivary gland chromosomes, and matched it to the profile of Su(var)3-9. Unlike Su(var)3-9, SetDB1 turned out to be an euchromatic protein that is absent from repeated DNA compartments, and is largely restricted to transcription start sites (TSSs) and 5' untranslated regions (5'UTRs) of ubiquitously expressed genes. Significant SetDB1 association is also observed at binding sites for the insulator protein CP190. SetDB1 and H3K9 di- and tri-methylated (me2 and me3)-enriched sites tend to display poor overlap. At the same time, SetDB1 has a clear connection with the distribution of H3K27me3 mark. SetDB1 binds outside the domains possessing this modification, and about half of the borders of H3K27me3 domains are decorated by SetDB1 together with actively transcribed genes. On the basis of poor correlation between the distribution of SetDB1 and H3K9 methylation marks, we speculate that, in somatic cells, SetDB1 may contribute to the methylation of a broader set of chromosomal proteins than just H3K9. In addition, SetDB1 can be expected to play a role in the establishment of chromatin functional domains.
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Affiliation(s)
| | - Daniil A Maksimov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia
| | - Stanislav E Romanov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia.,Laboratory of Epigenetics, Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Petr P Laktionov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia.,Laboratory of Epigenetics, Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Dmitry E Koryakov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia
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8
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Mačinković I, Theofel I, Hundertmark T, Kovač K, Awe S, Lenz J, Forné I, Lamp B, Nist A, Imhof A, Stiewe T, Renkawitz-Pohl R, Rathke C, Brehm A. Distinct CoREST complexes act in a cell-type-specific manner. Nucleic Acids Res 2019; 47:11649-11666. [PMID: 31701127 PMCID: PMC7145674 DOI: 10.1093/nar/gkz1050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 10/16/2019] [Accepted: 10/23/2019] [Indexed: 01/10/2023] Open
Abstract
CoREST has been identified as a subunit of several protein complexes that generate transcriptionally repressive chromatin structures during development. However, a comprehensive analysis of the CoREST interactome has not been carried out. We use proteomic approaches to define the interactomes of two dCoREST isoforms, dCoREST-L and dCoREST-M, in Drosophila. We identify three distinct histone deacetylase complexes built around a common dCoREST/dRPD3 core: A dLSD1/dCoREST complex, the LINT complex and a dG9a/dCoREST complex. The latter two complexes can incorporate both dCoREST isoforms. By contrast, the dLSD1/dCoREST complex exclusively assembles with the dCoREST-L isoform. Genome-wide studies show that the three dCoREST complexes associate with chromatin predominantly at promoters. Transcriptome analyses in S2 cells and testes reveal that different cell lineages utilize distinct dCoREST complexes to maintain cell-type-specific gene expression programmes: In macrophage-like S2 cells, LINT represses germ line-related genes whereas other dCoREST complexes are largely dispensable. By contrast, in testes, the dLSD1/dCoREST complex prevents transcription of germ line-inappropriate genes and is essential for spermatogenesis and fertility, whereas depletion of other dCoREST complexes has no effect. Our study uncovers three distinct dCoREST complexes that function in a lineage-restricted fashion to repress specific sets of genes thereby maintaining cell-type-specific gene expression programmes.
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Affiliation(s)
- Igor Mačinković
- Institute of Molecular Biology and Tumor Research, Biomedical Research Center, Philipps-University, Hans-Meerwein-Strasse 2, 35043, Marburg, Germany
| | - Ina Theofel
- Department of Biology, Philipps-University, Karl-von-Frisch-Strasse 8, 35043, Marburg, Germany
| | - Tim Hundertmark
- Department of Biology, Philipps-University, Karl-von-Frisch-Strasse 8, 35043, Marburg, Germany
| | - Kristina Kovač
- Institute of Molecular Biology and Tumor Research, Biomedical Research Center, Philipps-University, Hans-Meerwein-Strasse 2, 35043, Marburg, Germany
| | - Stephan Awe
- Institute of Molecular Biology and Tumor Research, Biomedical Research Center, Philipps-University, Hans-Meerwein-Strasse 2, 35043, Marburg, Germany
| | - Jonathan Lenz
- Institute of Molecular Biology and Tumor Research, Biomedical Research Center, Philipps-University, Hans-Meerwein-Strasse 2, 35043, Marburg, Germany
| | - Ignasi Forné
- Protein Analysis Unit, BioMedical Center, Faculty of Medicine, Ludwig-Maximilians-University Munich, Großhadernerstrasse 9, 82152 Martinsried, Germany
| | - Boris Lamp
- Genomics Core Facility, Institute of Molecular Oncology, Philipps-University, Hans-Meerwein-Strasse 3, 35043 Marburg, Germany
| | - Andrea Nist
- Genomics Core Facility, Institute of Molecular Oncology, Philipps-University, Hans-Meerwein-Strasse 3, 35043 Marburg, Germany
| | - Axel Imhof
- Protein Analysis Unit, BioMedical Center, Faculty of Medicine, Ludwig-Maximilians-University Munich, Großhadernerstrasse 9, 82152 Martinsried, Germany
| | - Thorsten Stiewe
- Genomics Core Facility, Institute of Molecular Oncology, Philipps-University, Hans-Meerwein-Strasse 3, 35043 Marburg, Germany
| | - Renate Renkawitz-Pohl
- Department of Biology, Philipps-University, Karl-von-Frisch-Strasse 8, 35043, Marburg, Germany
| | - Christina Rathke
- Department of Biology, Philipps-University, Karl-von-Frisch-Strasse 8, 35043, Marburg, Germany
| | - Alexander Brehm
- Institute of Molecular Biology and Tumor Research, Biomedical Research Center, Philipps-University, Hans-Meerwein-Strasse 2, 35043, Marburg, Germany
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9
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Sharma AB, Dimitrov S, Hamiche A, Van Dyck E. Centromeric and ectopic assembly of CENP-A chromatin in health and cancer: old marks and new tracks. Nucleic Acids Res 2019; 47:1051-1069. [PMID: 30590707 PMCID: PMC6379705 DOI: 10.1093/nar/gky1298] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 12/13/2018] [Accepted: 12/18/2018] [Indexed: 12/20/2022] Open
Abstract
The histone H3 variant CENP-A confers epigenetic identity to the centromere and plays crucial roles in the assembly and function of the kinetochore, thus ensuring proper segregation of our chromosomes. CENP-A containing nucleosomes exhibit unique structural specificities and lack the complex profile of gene expression-associated histone posttranslational modifications found in canonical histone H3 and the H3.3 variant. CENP-A mislocalization into noncentromeric regions resulting from its overexpression leads to chromosomal segregation aberrations and genome instability. Overexpression of CENP-A is a feature of many cancers and is associated with malignant progression and poor outcome. The recent years have seen impressive progress in our understanding of the mechanisms that orchestrate CENP-A deposition at native centromeres and ectopic loci. They have witnessed the description of novel, heterotypic CENP-A/H3.3 nucleosome particles and the exploration of the phenotypes associated with the deregulation of CENP-A and its chaperones in tumor cells. Here, we review the structural specificities of CENP-A nucleosomes, the epigenetic features that characterize the centrochromatin and the mechanisms and factors that orchestrate CENP-A deposition at centromeres. We then review our knowledge of CENP-A ectopic distribution, highlighting experimental strategies that have enabled key discoveries. Finally, we discuss the implications of deregulated CENP-A in cancer.
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Affiliation(s)
- Abhishek Bharadwaj Sharma
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health (LIH), 84 Val Fleuri, L-1526 Luxembourg, Luxembourg
| | - Stefan Dimitrov
- Université Grenoble Alpes, CNRS UMR 5309, INSERM U1209, Institute for Advanced Biosciences (IAB), Site Santé-Allée des Alpes, 38700 La Tronche, France.,Izmir Biomedicine and Genome Center, İzmir, Turkey
| | - Ali Hamiche
- Département de Génomique Fonctionnelle et Cancer, Institut de Génétique et Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, CNRS, INSERM, 67404 Illkirch Cedex, France
| | - Eric Van Dyck
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health (LIH), 84 Val Fleuri, L-1526 Luxembourg, Luxembourg
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10
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Parey E, Crombach A. Evolution of the Drosophila melanogaster Chromatin Landscape and Its Associated Proteins. Genome Biol Evol 2019; 11:660-677. [PMID: 30689829 PMCID: PMC6411481 DOI: 10.1093/gbe/evz019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2019] [Indexed: 12/30/2022] Open
Abstract
In the nucleus of eukaryotic cells, genomic DNA associates with numerous protein complexes and RNAs, forming the chromatin landscape. Through a genome-wide study of chromatin-associated proteins in Drosophila cells, five major chromatin types were identified as a refinement of the traditional binary division into hetero- and euchromatin. These five types were given color names in reference to the Greek word chroma. They are defined by distinct but overlapping combinations of proteins and differ in biological and biochemical properties, including transcriptional activity, replication timing, and histone modifications. In this work, we assess the evolutionary relationships of chromatin-associated proteins and present an integrated view of the evolution and conservation of the fruit fly Drosophila melanogaster chromatin landscape. We combine homology prediction across a wide range of species with gene age inference methods to determine the origin of each chromatin-associated protein. This provides insight into the evolution of the different chromatin types. Our results indicate that for the euchromatic types, YELLOW and RED, young associated proteins are more specialized than old ones; and for genes found in either chromatin type, intron/exon structure is lineage-specific. Next, we provide evidence that a subset of GREEN-associated proteins is involved in a centromere drive in D. melanogaster. Our results on BLUE chromatin support the hypothesis that the emergence of Polycomb Group proteins is linked to eukaryotic multicellularity. In light of these results, we discuss how the regulatory complexification of chromatin links to the origins of eukaryotic multicellularity.
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Affiliation(s)
- Elise Parey
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Université Paris, France.,Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Université Paris, Paris, France
| | - Anton Crombach
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Université Paris, France.,Inria, Antenne Lyon La Doua, Villeurbanne, France.,Université de Lyon, INSA-Lyon, LIRIS, UMR 5205, Villeurbanne, France
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11
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The histone methyltransferase G9a regulates tolerance to oxidative stress-induced energy consumption. PLoS Biol 2019; 17:e2006146. [PMID: 30860988 PMCID: PMC6413895 DOI: 10.1371/journal.pbio.2006146] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 02/06/2019] [Indexed: 12/24/2022] Open
Abstract
Stress responses are crucial processes that require activation of genetic programs that protect from the stressor. Stress responses are also energy consuming and can thus be deleterious to the organism. The mechanisms coordinating energy consumption during stress response in multicellular organisms are not well understood. Here, we show that loss of the epigenetic regulator G9a in Drosophila causes a shift in the transcriptional and metabolic responses to oxidative stress (OS) that leads to decreased survival time upon feeding the xenobiotic paraquat. During OS exposure, G9a mutants show overactivation of stress response genes, rapid depletion of glycogen, and inability to access lipid energy stores. The OS survival deficiency of G9a mutants can be rescued by a high-sugar diet. Control flies also show improved OS survival when fed a high-sugar diet, suggesting that energy availability is generally a limiting factor for OS tolerance. Directly limiting access to glycogen stores by knocking down glycogen phosphorylase recapitulates the OS-induced survival defects of G9a mutants. We propose that G9a mutants are sensitive to stress because they experience a net reduction in available energy due to (1) rapid glycogen use, (2) an inability to access lipid energy stores, and (3) an overinduced transcriptional response to stress that further exacerbates energy demands. This suggests that G9a acts as a critical regulatory hub between the transcriptional and metabolic responses to OS. Our findings, together with recent studies that established a role for G9a in hypoxia resistance in cancer cell lines, suggest that G9a is of wide importance in controlling the cellular and organismal response to multiple types of stress. Stress responses require proper activation of genetic programs to protect the organism from the stressor. However, the mechanisms controlling energy consumption during stress responses are not well understood. Here, we investigate the role of epigenetic modifier G9a in regulating metabolism and gene transcription during oxidative stress responses in Drosophila. Flies lacking G9a show a shift in the metabolic and transcriptional responses to oxidative stress, leading to decreased stress tolerance despite intact oxidative stress defense mechanisms. During oxidative stress exposure, G9a mutants show overactivation of stress response and many other genes, rapid depletion of glycogen energy stores, and an inability to access lipid energy stores. The increased susceptibility of G9a mutant flies to oxidative stress can be rescued simply by providing extra sugar. This suggests that G9a mutants are sensitive to stress because of reduced access to immediately available energy. Wild-type flies also become more tolerant to oxidative stress when they are fed extra sugar, whereas blocking energy access by genetically reducing a key metabolic enzyme leads to oxidative stress sensitivity. Though the genetic response to oxidative stress has long been appreciated, our study emphasizes the importance of energy metabolism for stress tolerance and identifies the histone methyltransferase G9a as an important player regulating both.
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12
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Anderson EM, Penrod RD, Barry SM, Hughes BW, Taniguchi M, Cowan CW. It is a complex issue: emerging connections between epigenetic regulators in drug addiction. Eur J Neurosci 2018; 50:2477-2491. [PMID: 30251397 DOI: 10.1111/ejn.14170] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 09/04/2018] [Accepted: 09/11/2018] [Indexed: 02/06/2023]
Abstract
Drug use leads to addiction in some individuals, but the underlying brain mechanisms that control the transition from casual drug use to an intractable substance use disorder (SUD) are not well understood. Gene x environment interactions such as the frequency of drug use and the type of substance used likely to promote maladaptive plastic changes in brain regions that are critical for controlling addiction-related behavior. Epigenetics encompasses a broad spectrum of mechanisms important for regulating gene transcription that are not dependent on changes in DNA base pair sequences. This review focuses on the proteins and complexes contributing to epigenetic modifications in the nucleus accumbens (NAc) following drug experience. We discuss in detail the three major mechanisms: histone acetylation and deacetylation, histone methylation, and DNA methylation. We discuss how drug use alters the regulation of the associated proteins regulating these processes and highlight how experimental manipulations of these proteins in the NAc can alter drug-related behaviors. Finally, we discuss the ways that histone modifications and DNA methylation coordinate actions by recruiting large epigenetic enzyme complexes to aid in transcriptional repression. Targeting these multiprotein epigenetic enzyme complexes - and the individual proteins that comprise them - might lead to effective therapeutics to reverse or treat SUDs in patients.
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Affiliation(s)
- Ethan M Anderson
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Medical University of South Carolina, 173 Ashley Ave, MSC 510, Charleston, SC, 29425-2030, USA
| | - Rachel D Penrod
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Medical University of South Carolina, 173 Ashley Ave, MSC 510, Charleston, SC, 29425-2030, USA
| | - Sarah M Barry
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Medical University of South Carolina, 173 Ashley Ave, MSC 510, Charleston, SC, 29425-2030, USA
| | - Brandon W Hughes
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Medical University of South Carolina, 173 Ashley Ave, MSC 510, Charleston, SC, 29425-2030, USA
| | - Makoto Taniguchi
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Medical University of South Carolina, 173 Ashley Ave, MSC 510, Charleston, SC, 29425-2030, USA
| | - Christopher W Cowan
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Medical University of South Carolina, 173 Ashley Ave, MSC 510, Charleston, SC, 29425-2030, USA
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13
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Xie L, Lin L, Huang S, Yang T, Shi D, Li X. Inhibition of Suv39H1 enhances transgenic IFNα-2b gene expression in Bcap-37 cells. Anim Biotechnol 2018; 30:358-365. [PMID: 30179066 DOI: 10.1080/10495398.2018.1500373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The low expression of exogenous transferred gene limited the application of transgenic animal technology. Suppressor of variegation 3 ∼ 9 homolog 1(SUV39H1) gene plays a prominent role on repressive heterochromatin and transcription. To understand if exogenous transgenic gene expression was affected by SUV39H1 epigenetic modification, in this paper, the effective shRNA fragments targeting SUV39H1 gene were first screened, their roles on expression of exogenous transgenic genes were determined by using Bcap-37 cell line with stable expressing IFNα-2b gene as a model, the preliminary regulation mechanism of SUV39H1 gene was investigated. The results showed that the designed shRNA1/2 fragments of SUV39H1 gene had an obvious inhibition effect on the expression of SUV39H1 gene, reached 53.07 and 31.28%, respectively by qRT-PCR analysis. Compared with the control group, the expression of IFNα-2b gene in transgenic Bcap-37 cells infected with shRNA1 and 2 viruses significantly increased by 96.25 and 121.08%, respectively (p < 0.05). In addition, the expression of DNMT1, HDAC1 and G9a gene in the shRNA infected cells reduced significantly, and the expression of the HAT1 gene increased significantly (p < 0.05). The above results indicated that the expression of exogenous transgenic gene could be promoted by suppressing SUV39H1 gene at the cell level.
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Affiliation(s)
- Liangliang Xie
- State Key Laboratory of Subtropical Bioresource Conservation and Utilization at Guangxi University , Guangxi , China
| | - Lang Lin
- State Key Laboratory of Subtropical Bioresource Conservation and Utilization at Guangxi University , Guangxi , China
| | - Shihai Huang
- College of Life Science and Technology, Guangxi University , Guangxi , China
| | - Ting Yang
- State Key Laboratory of Subtropical Bioresource Conservation and Utilization at Guangxi University , Guangxi , China
| | - Deshun Shi
- State Key Laboratory of Subtropical Bioresource Conservation and Utilization at Guangxi University , Guangxi , China
| | - Xiangping Li
- State Key Laboratory of Subtropical Bioresource Conservation and Utilization at Guangxi University , Guangxi , China
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14
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Kim SY, Hong M, Heo SH, Park S, Kwon TK, Sung YH, Oh Y, Lee S, Yi GS, Kim I. Inhibition of euchromatin histone-lysine N-methyltransferase 2 sensitizes breast cancer cells to tumor necrosis factor-related apoptosis-inducing ligand through reactive oxygen species-mediated activating transcription factor 4-C/EBP homologous protein-death receptor 5 pathway activation. Mol Carcinog 2018; 57:1492-1506. [PMID: 29964331 DOI: 10.1002/mc.22872] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 06/05/2018] [Accepted: 06/28/2018] [Indexed: 12/13/2022]
Abstract
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been characterized as an anti-cancer therapeutic agent with prominent cancer cell selectivity over normal cells. However, breast cancer cells are generally resistant to TRAIL, thus limiting its therapeutic potential. In this study, we found that BIX-01294, a selective inhibitor of euchromatin histone methyltransferase 2/G9a, is a strong TRAIL sensitizer in breast cancer cells. The combination of BIX-01294 and TRAIL decreased cell viability and led to an increase in the annexin V/propidium iodide-positive cell population, DNA fragmentation, and caspase activation. BIX-01294 markedly increased death receptor 5 (DR5) expression, while silencing of DR5 using small interfering RNAs abolished the TRAIL-sensitizing effect of BIX-01294. Specifically, BIX-01294 induced C/EBP homologous protein (CHOP)-mediated DR5 gene transcriptional activation and DR5 promoter activation was induced by upregulation of the protein kinase R-like endoplasmic reticulum kinase-mediated activating transcription factor 4 (ATF4). Moreover, inhibition of reactive oxygen species by N-acetyl-L-cysteine efficiently blocked BIX-01294-induced DR5 upregulation by inhibiting ATF4/CHOP expression, leading to diminished sensitization to TRAIL. These findings suggest that BIX-01294 sensitizes breast cancer cells to TRAIL by upregulating ATF4/CHOP-dependent DR5 expression with a reactive oxygen species-dependent manner. Furthermore, combination treatment with BIX-01294 and TRAIL suppressed tumor growth and induced apoptosis in vivo. In conclusion, we found that epigenetic regulation can contribute to the development of resistance to cancer therapeutics such as TRAIL, and further studies of unfolded protein responses and the associated epigenetic regulatory mechanisms may lead to the discovery of new molecular targets for effective cancer therapy.
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Affiliation(s)
- So Young Kim
- ASAN Institute for Life Sciences, ASAN Medical Center, Seoul, Republic of Korea
| | - MiNa Hong
- ASAN Institute for Life Sciences, ASAN Medical Center, Seoul, Republic of Korea
| | - Seung-Ho Heo
- Department of Convergence Medicine, ASAN Institute for Life Sciences, ASAN Medical Center, Seoul, Republic of Korea
| | - Sojung Park
- ASAN Institute for Life Sciences, ASAN Medical Center, Seoul, Republic of Korea
| | - Taeg Kyu Kwon
- Department of Immunology, School of Medicine, Keimyung University, Daegu, Republic of Korea
| | - Young Hoon Sung
- ASAN Institute for Life Sciences, ASAN Medical Center, Seoul, Republic of Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yumin Oh
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Seulki Lee
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Gwan-Su Yi
- Department of Bio and Brain Engineering, KAIST, Daejeon, Republic of Korea
| | - Inki Kim
- ASAN Institute for Life Sciences, ASAN Medical Center, Seoul, Republic of Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, Republic of Korea
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15
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Song W, Zsindely N, Faragó A, Marsh JL, Bodai L. Systematic genetic interaction studies identify histone demethylase Utx as potential target for ameliorating Huntington's disease. Hum Mol Genet 2018; 27:649-666. [PMID: 29281014 PMCID: PMC5886221 DOI: 10.1093/hmg/ddx432] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 12/12/2017] [Accepted: 12/15/2017] [Indexed: 01/29/2023] Open
Abstract
Huntington's disease (HD) is a dominantly inherited neurodegenerative disease caused by alterations in the huntingtin gene (htt). Transcriptional dysregulation is an early event in HD progression. Protein acetylation and methylation particularly on histones regulates chromatin structure thereby preventing or facilitating transcription. Although protein acetylation has been found to affect HD symptoms, little is known about the potential role of protein methylation in HD pathology. In recent years, a series of proteins have been described that are responsible for methylating and demethylating histones as well as other proteins. We carried out systematic genetic interaction studies testing lysine and arginine methylases and demethylases in a Drosophila melanogaster HD model. We found that modulating methylation enzymes that typically affect histone positions H3K4, H3K36 or H3K79 had varying effects on HD pathology while modulating ones that typically affect constitutive heterochromatin marks at H3K9 and H4K20 generally had limited impact on HD pathology. In contrast, modulating enzymes acting on the facultative heterochromatin mark at H3K27 had specific effects on HD pathology, with reduction of the demethylase Utx rescuing HTT-induced pathology while reducing Polycomb Repressive Complex2 core methylase components led to more aggressive pathology. Further exploration of the mechanism underlying the methylation-specific interactions suggest that these lysine and arginine methylases and demethylases are likely exerting their influence through non-histone targets. These results highlight a novel therapeutic approach for HD in the form of Utx inhibition.
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Affiliation(s)
- Wan Song
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA 92697, USA
| | - Nóra Zsindely
- Department of Biochemistry and Molecular Biology, University of Szeged, 6726 Szeged, Hungary
| | - Anikó Faragó
- Department of Biochemistry and Molecular Biology, University of Szeged, 6726 Szeged, Hungary
- Doctoral School in Biology, Faculty of Science and Informatics, University of Szeged, 6726 Szeged, Hungary
| | - J Lawrence Marsh
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA 92697, USA
| | - László Bodai
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA 92697, USA
- Department of Biochemistry and Molecular Biology, University of Szeged, 6726 Szeged, Hungary
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16
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Gupta V, Vale PF. Nonlinear disease tolerance curves reveal distinct components of host responses to viral infection. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170342. [PMID: 28791163 PMCID: PMC5541558 DOI: 10.1098/rsos.170342] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 05/31/2017] [Indexed: 05/07/2023]
Abstract
The ability to tolerate infection is a key component of host defence and offers potential novel therapeutic approaches for infectious diseases. To yield successful targets for therapeutic intervention, it is important that the analytical tools employed to measure disease tolerance are able to capture distinct host responses to infection. Here, we show that commonly used methods that estimate tolerance as a linear relationship should be complemented with more flexible, nonlinear estimates of this relationship which may reveal variation in distinct components such as host vigour, sensitivity to increases in pathogen loads, and the severity of the infection. To illustrate this, we measured the survival of Drosophila melanogaster carrying either a functional or non-functional regulator of the JAK-STAT immune pathway (G9a) when challenged with a range of concentrations of Drosophila C virus (DCV). While classical linear model analyses indicated that G9a affected tolerance only in females, a more powerful nonlinear logistic model showed that G9a mediates viral tolerance to different extents in both sexes. This analysis also revealed that G9a acts by changing the sensitivity to increasing pathogen burdens, but does not reduce the ultimate severity of disease. These results indicate that fitting nonlinear models to host health-pathogen burden relationships may offer better and more detailed estimates of disease tolerance.
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Affiliation(s)
- Vanika Gupta
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EH9 3FL Edinburgh, UK
| | - Pedro F. Vale
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EH9 3FL Edinburgh, UK
- Centre for Immunity, Infection and Evolution, University of Edinburgh, EH9 3FL Edinburgh, UK
- Author for correspondence: Pedro F. Vale e-mail:
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17
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Ye K, Wang S, Wang J, Han H, Ma B, Yang Y. Zebularine enhances apoptosis of human osteosarcoma cells by suppressing methylation of ARHI. Cancer Sci 2016; 107:1851-1857. [PMID: 27685841 PMCID: PMC5198947 DOI: 10.1111/cas.13088] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 09/22/2016] [Accepted: 09/24/2016] [Indexed: 01/08/2023] Open
Abstract
ARHI is an imprinted tumor suppressor gene and its methylation suppresses ARHI transcription levels to cause the development and progression of malignant tumors. Zebularine exerts a demethylation function for tumor suppressor genes. Our study aims to investigate the effect and mechanism of action of zebularine on the epigenetic modification of the ARHI gene, and whether this effect may modulate the viability and apoptosis of human osteosarcoma cells. We found that zebularine inhibited the viability and promoted apoptosis in osteosarcoma cells. Zebularine potentiated the expression of ARHI at both the protein and mRNA level. This was related to the downregulation of methylation of ARHI caused by zebularine. Zebularine suppressed the interaction of DNA methyltransferase 1 (DNMT1) with histone methyltransferase G9a, but had no effect on G9a alone. Knockdown of DNMT1 or G9a can induce a reduction of ARHI methylation. Therefore, we inferred that zebularine was likely to directly repress DNMT1 alone, but G9a was necessary to regulate the function of DNMT1 on ARHI methylation. Moreover, knockdown of ARHI rescued cell viability and apoptosis under the zebularine‐treated condition. We showed that zebularine inhibited viability and promoted apoptosis by disturbing the interaction between DNMT1 and G9a, thereby resulting in lower ARHI methylation and elevated ARHI expression in osteosarcoma cells.
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Affiliation(s)
- Kaishan Ye
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, Gansu, China
| | - Shuanke Wang
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, Gansu, China
| | - Jing Wang
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, Gansu, China
| | - Hua Han
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, Gansu, China
| | - Bing Ma
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, Gansu, China
| | - Yong Yang
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, Gansu, China
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18
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Shimaji K, Konishi T, Yoshida H, Kimura H, Yamaguchi M. Genome-wide genetic screen identified the link between dG9a and epidermal growth factor receptor signaling pathway in vivo. Exp Cell Res 2016; 346:53-64. [PMID: 27343629 DOI: 10.1016/j.yexcr.2016.06.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 05/27/2016] [Accepted: 06/21/2016] [Indexed: 10/21/2022]
Abstract
G9a is one of the histone H3 Lys 9 (H3K9) specific methyltransferases first identified in mammals. Drosophila G9a (dG9a) has been reported to induce H3K9 dimethylation in vivo, and the target genes of dG9a were identified during embryonic and larval stages. Although dG9a is important for a variety of developmental processes, the link between dG9a and signaling pathways are not addressed yet. Here, by genome-wide genetic screen, taking advantage of the rough eye phenotype of flies that over-express dG9a in eye discs, we identified 16 genes that enhanced the rough eye phenotype induced by dG9a over-expression. These 16 genes included Star, anterior open, bereft and F-box and leucine-rich repeat protein 6 which are components of epidermal growth factor receptor (EGFR) signaling pathway. When dG9a over-expression was combined with mutation of Star, differentiation of R7 photoreceptors in eye imaginal discs as well as cone cells and pigment cells in pupal retinae was severely inhibited. Furthermore, the dG9a over-expression reduced the activated ERK signals in eye discs. These data demonstrate a strong genetic link between dG9a and the EGFR signaling pathway.
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Affiliation(s)
- Kouhei Shimaji
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Takahiro Konishi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; Insect Biomedical Research Center, 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; Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Hiroshi Kimura
- Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
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19
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Sienski G, Batki J, Senti KA, Dönertas D, Tirian L, Meixner K, Brennecke J. Silencio/CG9754 connects the Piwi-piRNA complex to the cellular heterochromatin machinery. Genes Dev 2015; 29:2258-71. [PMID: 26494711 PMCID: PMC4647559 DOI: 10.1101/gad.271908.115] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 10/05/2015] [Indexed: 11/24/2022]
Abstract
In this study, Sienski et al. characterize CG9754/Silencio as an essential piRNA pathway factor that is required for Piwi's nuclear function in guiding the transcriptional silencing of transposons. These results provide novel insight into the transcriptional silencing process downstream from Piwi and the regulation of piRNA-guided heterochromatin formation. The repression of transposable elements in eukaryotes often involves their transcriptional silencing via targeted chromatin modifications. In animal gonads, nuclear Argonaute proteins of the PIWI clade complexed with small guide RNAs (piRNAs) serve as sequence specificity determinants in this process. How binding of nuclear PIWI–piRNA complexes to nascent transcripts orchestrates heterochromatin formation and transcriptional silencing is unknown. Here, we characterize CG9754/Silencio as an essential piRNA pathway factor that is required for Piwi-mediated transcriptional silencing in Drosophila. Ectopic targeting of Silencio to RNA or DNA is sufficient to elicit silencing independently of Piwi and known piRNA pathway factors. Instead, Silencio requires the H3K9 methyltransferase Eggless/SetDB1 for its silencing ability. In agreement with this, SetDB1, but not Su(var)3-9, is required for Piwi-mediated transcriptional silencing genome-wide. Due to its interaction with the target-engaged Piwi–piRNA complex, we suggest that Silencio acts as linker between the sequence specificity factor Piwi and the cellular heterochromatin machinery.
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Affiliation(s)
- Grzegorz Sienski
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Julia Batki
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Kirsten-André Senti
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Derya Dönertas
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Laszlo Tirian
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Katharina Meixner
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Julius Brennecke
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), 1030 Vienna, Austria
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20
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Shimaji K, Konishi T, Tanaka S, Yoshida H, Kato Y, Ohkawa Y, Sato T, Suyama M, Kimura H, Yamaguchi M. Genomewide identification of target genes of histone methyltransferase dG9a duringDrosophilaembryogenesis. Genes Cells 2015; 20:902-14. [DOI: 10.1111/gtc.12281] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 07/22/2015] [Indexed: 01/08/2023]
Affiliation(s)
- Kouhei Shimaji
- Department of Applied Biology; Kyoto Institute of Technology; Matsugasaki Sakyo-ku Kyoto 606-8585 Japan
- Insect Biomedical Research Center; Kyoto Institute of Technology; Matsugasaki Sakyo-ku Kyoto 606-8585 Japan
| | - Takahiro Konishi
- Department of Applied Biology; Kyoto Institute of Technology; Matsugasaki Sakyo-ku Kyoto 606-8585 Japan
- Insect Biomedical Research Center; Kyoto Institute of Technology; Matsugasaki Sakyo-ku Kyoto 606-8585 Japan
| | - Shintaro Tanaka
- Department of Applied Biology; Kyoto Institute of Technology; Matsugasaki Sakyo-ku Kyoto 606-8585 Japan
- Insect Biomedical Research Center; 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
- Insect Biomedical Research Center; Kyoto Institute of Technology; Matsugasaki Sakyo-ku Kyoto 606-8585 Japan
| | - Yasuko Kato
- Department of Applied Biology; Kyoto Institute of Technology; Matsugasaki Sakyo-ku Kyoto 606-8585 Japan
- Insect Biomedical Research Center; Kyoto Institute of Technology; Matsugasaki Sakyo-ku Kyoto 606-8585 Japan
| | - Yasuyuki Ohkawa
- Department of Advanced Medical Initiatives; Faculty of Medicine; Kyushu University; Maidashi Fukuoka 812-8582 Japan
| | - Tetsuya Sato
- Division of Bioinformatics; Medical Institute of Bioregulation; Kyushu University; Maidashi Fukuoka 812-8582 Japan
| | - Mikita Suyama
- Division of Bioinformatics; Medical Institute of Bioregulation; Kyushu University; Maidashi Fukuoka 812-8582 Japan
| | - Hiroshi Kimura
- Department of Biological Sciences; Graduate School of Bioscience and Biotechnology; Tokyo Institute of Technology; Nagatsuta Midori-ku Yokohama 226-8501 Japan
| | - Masamitsu Yamaguchi
- Department of Applied Biology; Kyoto Institute of Technology; Matsugasaki Sakyo-ku Kyoto 606-8585 Japan
- Insect Biomedical Research Center; Kyoto Institute of Technology; Matsugasaki Sakyo-ku Kyoto 606-8585 Japan
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21
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Merkling SH, Bronkhorst AW, Kramer JM, Overheul GJ, Schenck A, Van Rij RP. The epigenetic regulator G9a mediates tolerance to RNA virus infection in Drosophila. PLoS Pathog 2015; 11:e1004692. [PMID: 25880195 PMCID: PMC4399909 DOI: 10.1371/journal.ppat.1004692] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/21/2015] [Indexed: 01/01/2023] Open
Abstract
Little is known about the tolerance mechanisms that reduce the negative effects of microbial infection on host fitness. Here, we demonstrate that the histone H3 lysine 9 methyltransferase G9a regulates tolerance to virus infection by shaping the response of the evolutionary conserved Jak-Stat pathway in Drosophila. G9a-deficient mutants are more sensitive to RNA virus infection and succumb faster to infection than wild-type controls, which was associated with strongly increased Jak-Stat dependent responses, but not with major differences in viral load. Genetic experiments indicate that hyperactivated Jak-Stat responses are associated with early lethality in virus-infected flies. Our results identify an essential epigenetic mechanism underlying tolerance to virus infection. Multicellular organisms deploy various strategies to fight microbial infections. Invading pathogens may be eradicated directly by antimicrobial effectors of the immune system. Another strategy consists of increasing the tolerance of the host to infection, for example, by limiting the adverse effects of the immune response. The molecular mechanisms underlying this novel concept remain largely uncharacterized. Here, we demonstrate that the epigenetic regulator G9a mediates tolerance to virus infection in Drosophila. We found that G9a-deficient flies succumb faster than control flies to infection with RNA viruses, but that the viral burden did not significantly differ. Unexpectedly, mutant flies express higher levels of genes that are regulated by the Jak-Stat signaling pathway, which in other studies was found to be important for antiviral defense. Exploiting the genetic toolbox in Drosophila, we demonstrate that Jak-Stat hyperactivation induces early mortality after virus infection. Precise control of immune pathways is essential to ensure efficient immunity, while preventing damage due to excessive immune responses. Our results indicate that G9a, an epigenetic modifier, dampens Jak-Stat responses to prevent immunopathology. Therefore, we propose epigenetic regulation of immunity as a new paradigm for disease tolerance.
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Affiliation(s)
- Sarah H. Merkling
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alfred W. Bronkhorst
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jamie M. Kramer
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gijs J. Overheul
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Annette Schenck
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ronald P. Van Rij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
- * E-mail:
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22
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Zhang B, Mehrotra S, Ng WL, Calvi BR. Low levels of p53 protein and chromatin silencing of p53 target genes repress apoptosis in Drosophila endocycling cells. PLoS Genet 2014; 10:e1004581. [PMID: 25211335 PMCID: PMC4161308 DOI: 10.1371/journal.pgen.1004581] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 07/03/2014] [Indexed: 12/23/2022] Open
Abstract
Apoptotic cell death is an important response to genotoxic stress that prevents oncogenesis. It is known that tissues can differ in their apoptotic response, but molecular mechanisms are little understood. Here, we show that Drosophila polyploid endocycling cells (G/S cycle) repress the apoptotic response to DNA damage through at least two mechanisms. First, the expression of all the Drosophila p53 protein isoforms is strongly repressed at a post-transcriptional step. Second, p53-regulated pro-apoptotic genes are epigenetically silenced in endocycling cells, preventing activation of a paused RNA Pol II by p53-dependent or p53-independent pathways. Over-expression of the p53A isoform did not activate this paused RNA Pol II complex in endocycling cells, but over-expression of the p53B isoform with a longer transactivation domain did, suggesting that dampened p53B protein levels are crucial for apoptotic repression. We also find that the p53A protein isoform is ubiquitinated and degraded by the proteasome in endocycling cells. In mitotic cycling cells, p53A was the only isoform expressed to detectable levels, and its mRNA and protein levels increased after irradiation, but there was no evidence for an increase in protein stability. However, our data suggest that p53A protein stability is regulated in unirradiated cells, which likely ensures that apoptosis does not occur in the absence of stress. Without irradiation, both p53A protein and a paused RNA pol II were pre-bound to the promoters of pro-apoptotic genes, preparing mitotic cycling cells for a rapid apoptotic response to genotoxic stress. Together, our results define molecular mechanisms by which different cells in development modulate their apoptotic response, with broader significance for the survival of normal and cancer polyploid cells in mammals. In order to maintain genome integrity, eukaryotic cells have evolved multiple ways to respond to DNA damage stress. One of the major cellular responses is apoptosis, during which the cell undergoes programmed cell death in order to prevent the propagation of the damaged genome to daughter cells. Although clinical observations and other studies have shown that tissues can differ in their apoptotic response, the molecular mechanisms underlying these differences are largely unknown. We have shown in our model system, Drosophila, that endocycling cells do not initiate cell death in response to DNA damage. The endocycle is a cell cycle variation that is widely found in nature and conserved from plant to animals. During the endocycle, cells duplicate their genomic DNA but do not enter mitosis to segregate chromosomes, resulting in a polyploid genome content. In this study, we investigate how the apoptotic response to DNA damage is repressed in endocycling cells. We find that the Drosophila ortholog of the human p53 tumor suppressor protein is expressed at very low levels in endocycling cells. Moreover, the downstream pro-apoptotic genes that are regulated by p53 are epigenetically silenced in endocycling cells. Our results provide important insights into tissue-specific apoptotic responses in development, with possible broader impact on understanding radiation therapy response and cancer of different tissues.
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Affiliation(s)
- Bingqing Zhang
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Sonam Mehrotra
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Wei Lun Ng
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Brian R. Calvi
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
- * E-mail:
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23
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Wang SH, Nan R, Accardo MC, Sentmanat M, Dimitri P, Elgin SCR. A distinct type of heterochromatin at the telomeric region of the Drosophila melanogaster Y chromosome. PLoS One 2014; 9:e86451. [PMID: 24475122 PMCID: PMC3901700 DOI: 10.1371/journal.pone.0086451] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 12/16/2013] [Indexed: 11/24/2022] Open
Abstract
Heterochromatin assembly and its associated phenotype, position effect variegation (PEV), provide an informative system to study chromatin structure and genome packaging. In the fruit fly Drosophila melanogaster, the Y chromosome is entirely heterochromatic in all cell types except the male germline; as such, Y chromosome dosage is a potent modifier of PEV. However, neither Y heterochromatin composition, nor its assembly, has been carefully studied. Here, we report the mapping and characterization of eight reporter lines that show male-specific PEV. In all eight cases, the reporter insertion sites lie in the telomeric transposon array (HeT-A and TART-B2 homologous repeats) of the Y chromosome short arm (Ys). Investigations of the impact on the PEV phenotype of mutations in known heterochromatin proteins (i.e., modifiers of PEV) show that this Ys telomeric region is a unique heterochromatin domain: it displays sensitivity to mutations in HP1a, EGG and SU(VAR)3-9, but no sensitivity to Su(z)2 mutations. It appears that the endo-siRNA pathway plays a major targeting role for this domain. Interestingly, an ectopic copy of 1360 is sufficient to induce a piRNA targeting mechanism to further enhance silencing of a reporter cytologically localized to the Ys telomere. These results demonstrate the diversity of heterochromatin domains, and the corresponding variation in potential targeting mechanisms.
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Affiliation(s)
- Sidney H. Wang
- Department of Biology, Washington University, St. Louis, Missouri, United States of America
| | - Ruth Nan
- Department of Biology, Washington University, St. Louis, Missouri, United States of America
| | - Maria C. Accardo
- Dipartimento di Biologia e Biotecnologie “Charles Darwin” and Istituto Pasteur Fondazione Cenci-Bolognetti, Sapienza Università di Roma, Roma, Italy
| | - Monica Sentmanat
- Department of Biology, Washington University, St. Louis, Missouri, United States of America
| | - Patrizio Dimitri
- Dipartimento di Biologia e Biotecnologie “Charles Darwin” and Istituto Pasteur Fondazione Cenci-Bolognetti, Sapienza Università di Roma, Roma, Italy
| | - Sarah C. R. Elgin
- Department of Biology, Washington University, St. Louis, Missouri, United States of America
- * E-mail:
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24
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Song S, Yuan Y, Lu J, Li Q, Zhu Z, Fan Q, Xue Y, Lai ZC, Zhang W. The Drosophila ortholog of breast cancer metastasis suppressor gene, dBrms1, is critical for developmental timing through regulating ecdysone signaling. Dev Biol 2013; 380:344-50. [DOI: 10.1016/j.ydbio.2013.05.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 05/10/2013] [Accepted: 05/12/2013] [Indexed: 01/24/2023]
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25
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Huang XA, Yin H, Sweeney S, Raha D, Snyder M, Lin H. A major epigenetic programming mechanism guided by piRNAs. Dev Cell 2013; 24:502-16. [PMID: 23434410 DOI: 10.1016/j.devcel.2013.01.023] [Citation(s) in RCA: 177] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 01/10/2013] [Accepted: 01/30/2013] [Indexed: 11/29/2022]
Abstract
A central enigma in epigenetics is how epigenetic factors are guided to specific genomic sites for their function. Previously, we reported that a Piwi-piRNA complex associates with the piRNA-complementary site in the Drosophila genome and regulates its epigenetic state. Here, we report that Piwi-piRNA complexes bind to numerous piRNA-complementary sequences throughout the genome, implicating piRNAs as a major mechanism that guides Piwi and Piwi-associated epigenetic factors to program the genome. To test this hypothesis, we demonstrate that inserting piRNA-complementary sequences to an ectopic site leads to Piwi, HP1a, and Su(var)3-9 recruitment to the site as well as H3K9me2/3 enrichment and reduced RNA polymerase II association, indicating that piRNA is both necessary and sufficient to recruit Piwi and epigenetic factors to specific genomic sites. Piwi deficiency drastically changed the epigenetic landscape and polymerase II profile throughout the genome, revealing the Piwi-piRNA mechanism as a major epigenetic programming mechanism in Drosophila.
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Affiliation(s)
- Xiao A Huang
- Yale Stem Cell Center and Department of Cell Biology, Yale School of Medicine, New Haven, CT 06519, USA
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26
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27
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Figueiredo MLA, Philip P, Stenberg P, Larsson J. HP1a recruitment to promoters is independent of H3K9 methylation in Drosophila melanogaster. PLoS Genet 2012; 8:e1003061. [PMID: 23166515 PMCID: PMC3499360 DOI: 10.1371/journal.pgen.1003061] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 09/19/2012] [Indexed: 11/19/2022] Open
Abstract
Heterochromatin protein 1 (HP1) proteins, recognized readers of the heterochromatin mark methylation of histone H3 lysine 9 (H3K9me), are important regulators of heterochromatin-mediated gene silencing and chromosome structure. In Drosophila melanogaster three histone lysine methyl transferases (HKMTs) are associated with the methylation of H3K9: Su(var)3-9, Setdb1, and G9a. To probe the dependence of HP1a binding on H3K9me, its dependence on these three HKMTs, and the division of labor between the HKMTs, we have examined correlations between HP1a binding and H3K9me patterns in wild type and null mutants of these HKMTs. We show here that Su(var)3-9 controls H3K9me-dependent binding of HP1a in pericentromeric regions, while Setdb1 controls it in cytological region 2L:31 and (together with POF) in chromosome 4. HP1a binds to the promoters and within bodies of active genes in these three regions. More importantly, however, HP1a binding at promoters of active genes is independent of H3K9me and POF. Rather, it is associated with heterochromatin protein 2 (HP2) and open chromatin. Our results support a hypothesis in which HP1a nucleates with high affinity independently of H3K9me in promoters of active genes and then spreads via H3K9 methylation and transient looping contacts with those H3K9me target sites. HP1 is a key protein in heterochromatin and epigenetic silencing, a phenomenon involving chromatin condensation. It is generally accepted that HP1 forms a dimer that links two adjacent nucleosomes through interactions with histone 3 methylated at lysine 9 (H3K9me). Since HP1 also interacts with the histone lysine methyltransferases (HKMTs) generating this modification, histone H3 becomes methylated and HP1 spreading is propagated. Here, we show that HP1a in Drosophila binds to promoters of active genes on chromosome 4 and pericentromeric regions. In contrast to current dogma, this binding is independent of H3K9me. In the presence of the HKMTs and H3K9me, HP1a is also enriched within the bodies of the bound genes. These findings shed new light on the role of HP1a and the epigenetic nature of this chromatin mark. We propose that HP1a interacts independently of H3K9me with the nucleosome with high affinity, probably via the H3 histone-fold. This interaction is followed by a more transient interaction between HP1a and H3K9me, which results in spreading of the HP1a enrichment into gene bodies. Overall, the presented results and hypothesized model provide an explanation for this epigenetic mark and possibly more general insights into the relationships between chromo-domain proteins and methylated histones.
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Affiliation(s)
| | - Philge Philip
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Computational Life Science Cluster (CLiC), Umeå University, Umeå, Sweden
| | - Per Stenberg
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Computational Life Science Cluster (CLiC), Umeå University, Umeå, Sweden
| | - Jan Larsson
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- * E-mail:
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28
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Ito S, Fujiyama-Nakamura S, Kimura S, Lim J, Kamoshida Y, Shiozaki-Sato Y, Sawatsubashi S, Suzuki E, Tanabe M, Ueda T, Murata T, Kato H, Ohtake F, Fujiki R, Miki T, Kouzmenko A, Takeyama KI, Kato S. Epigenetic silencing of core histone genes by HERS in Drosophila. Mol Cell 2012; 45:494-504. [PMID: 22365829 DOI: 10.1016/j.molcel.2011.12.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 09/13/2011] [Accepted: 12/02/2011] [Indexed: 12/23/2022]
Abstract
Cell cycle-dependent expression of canonical histone proteins enables newly synthesized DNA to be integrated into chromatin in replicating cells. However, the molecular basis of cell cycle-dependency in the switching of histone gene regulation remains to be uncovered. Here, we report the identification and biochemical characterization of a molecular switcher, HERS (histone gene-specific epigenetic repressor in late S phase), for nucleosomal core histone gene inactivation in Drosophila. HERS protein is phosphorylated by a cyclin-dependent kinase (Cdk) at the end of S-phase. Phosphorylated HERS binds to histone gene regulatory regions and anchors HP1 and Su(var)3-9 to induce chromatin inactivation through histone H3 lysine 9 methylation. These findings illustrate a salient molecular switch linking epigenetic gene silencing to cell cycle-dependent histone production.
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Affiliation(s)
- Saya Ito
- Institute of Molecular and Cellular Biosciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
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29
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Wang X, Pan L, Wang S, Zhou J, McDowell W, Park J, Haug J, Staehling K, Tang H, Xie T. Histone H3K9 trimethylase Eggless controls germline stem cell maintenance and differentiation. PLoS Genet 2011; 7:e1002426. [PMID: 22216012 PMCID: PMC3245301 DOI: 10.1371/journal.pgen.1002426] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 11/04/2011] [Indexed: 11/18/2022] Open
Abstract
Epigenetic regulation plays critical roles in the regulation of cell proliferation, fate determination, and survival. It has been shown to control self-renewal and lineage differentiation of embryonic stem cells. However, epigenetic regulation of adult stem cell function remains poorly defined. Drosophila ovarian germline stem cells (GSCs) are a productive adult stem cell system for revealing regulatory mechanisms controlling self-renewal and differentiation. In this study, we show that Eggless (Egg), a H3K9 methyltransferase in Drosophila, is required in GSCs for controlling self-renewal and in escort cells for regulating germ cell differentiation. egg mutant ovaries primarily exhibit germ cell differentiation defects in young females and gradually lose GSCs with time, indicating that Egg regulates both germ cell maintenance and differentiation. Marked mutant egg GSCs lack expression of trimethylated H3K9 (H3k9me3) and are rapidly lost from the niche, but their mutant progeny can still differentiate into 16-cell cysts, indicating that Egg is required intrinsically to control GSC self-renewal but not differentiation. Interestingly, BMP-mediated transcriptional repression of differentiation factor bam in marked egg mutant GSCs remains normal, indicating that Egg is dispensable for BMP signaling in GSCs. Normally, Bam and Bgcn interact with each other to promote GSC differentiation. Interestingly, marked double mutant egg bgcn GSCs are still lost, but their progeny are able to differentiate into 16-cell cysts though bgcn mutant GSCs normally do not differentiate, indicating that Egg intrinsically controls GSC self-renewal through repressing a Bam/Bgcn-independent pathway. Surprisingly, RNAi-mediated egg knockdown in escort cells leads to their gradual loss and a germ cell differentiation defect. The germ cell differentiation defect is at least in part attributed to an increase in BMP signaling in the germ cell differentiation niche. Therefore, this study has revealed the essential roles of histone H3K9 trimethylation in controlling stem cell maintenance and differentiation through distinct mechanisms.
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Affiliation(s)
- Xiaoxi Wang
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Lei Pan
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- The Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Su Wang
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, United States of America
| | - Jian Zhou
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - William McDowell
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Jungeun Park
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Jeff Haug
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Karen Staehling
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Hong Tang
- The Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Ting Xie
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, United States of America
- * E-mail:
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30
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Kato Y, Ushijima Y, Yamaguchi M. Identification of nuclear localization signals of Drosophila G9a histone H3 methyltransferase. Cell Struct Funct 2011; 36:121-9. [PMID: 21512259 DOI: 10.1247/csf.10027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
G9a is one of the well-characterized histone methyltransferases. G9a regulates H3K9 mono- and dimethylation at euchromatic region and consequently plays important roles in euchromatic gene regulation. Mammalian G9a contains several distinct domains, such as GHD (G9a homology domain), ANK, preSET, SET and PostSET. These domains are highly conserved between mammals and Drosophila. Although mammalian G9a has nuclear localization signal (NLS) in its N-terminal region, the amino acid sequences of this region are not conserved in Drosophila. Here we have examined the subcellular localization of a series of truncated forms of Drosophila G9a (dG9a). The identified region (aa337-aa470) responsible for nuclear localization of dG9a contains four short stretches of positively charged basic amino acids (NLS1, aa334-aa345; NLS2, aa366-aa378; NLS3, aa407-aa419; NLS4, aa461-aa472). Each of NLS1, NLS3 and NLS4 is sufficient for the nuclear localization when they are fused with the enhanced green fluorescent protein. These NLSs of dG9a are distinct from those of mammalian G9a in their positions and amino acid sequences.
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Affiliation(s)
- Yasuko Kato
- Department of Applied Biology and Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Kyoto 606-8585, Japan
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31
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The SUUR protein is involved in binding of SU(VAR)3-9 and methylation of H3K9 and H3K27 in chromosomes of Drosophila melanogaster. Chromosome Res 2011; 19:235-49. [PMID: 21340745 DOI: 10.1007/s10577-011-9193-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2010] [Revised: 01/30/2011] [Accepted: 02/02/2011] [Indexed: 10/25/2022]
Abstract
In the present work, we found that the SUUR protein is required for the SU(VAR)3-9 enzyme to bind to the salivary gland polytene chromosomes. The SuUR mutation results in loss of SU(VAR)3-9 on the chromosomes, whereas artificial expression of the SuUR gene restores its binding. The SUUR protein is also involved in methylation of the residues H3K9 and H3K27. However, mono-, di-, and tri-methylated forms of H3K9 and H3K27 behave differently in various chromosomal domains in response to the SuUR mutation. Euchromatin and chromosome 4 are almost completely deprived of mono-, di-, and tri-methylation of H3K9. In the chromocenter, mono-methylation is reduced, di-methylation shows no noticeable changes, and tri-methylation is lost. Furthermore, mono- and di-methylation of H3K27 are not influenced by the SuUR mutation, whereas tri-methylation is lost in the chromocenter. Artificial expression of the SuUR gene on the SuUR (-) background restores the pattern of methylated residues characteristic for the wild type.
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32
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Illi B, Colussi C, Rosati J, Spallotta F, Nanni S, Farsetti A, Capogrossi MC, Gaetano C. NO points to epigenetics in vascular development. Cardiovasc Res 2011; 90:447-56. [PMID: 21345806 DOI: 10.1093/cvr/cvr056] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Our understanding of epigenetic mechanisms important for embryonic vascular development and cardiovascular differentiation is still in its infancy. Although molecular analyses, including massive genome sequencing and/or in vitro/in vivo targeting of specific gene sets, has led to the identification of multiple factors involved in stemness maintenance or in the early processes of embryonic layers specification, very little is known about the epigenetic commitment to cardiovascular lineages. The object of this review will be to outline the state of the art in this field and trace the perspective therapeutic consequences of studies aimed at elucidating fundamental epigenetic networks. Special attention will be paid to the emerging role of nitric oxide in this field.
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Affiliation(s)
- Barbara Illi
- Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
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33
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Kramer JM, Kochinke K, Oortveld MAW, Marks H, Kramer D, de Jong EK, Asztalos Z, Westwood JT, Stunnenberg HG, Sokolowski MB, Keleman K, Zhou H, van Bokhoven H, Schenck A. Epigenetic regulation of learning and memory by Drosophila EHMT/G9a. PLoS Biol 2011; 9:e1000569. [PMID: 21245904 PMCID: PMC3014924 DOI: 10.1371/journal.pbio.1000569] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 11/10/2010] [Indexed: 11/18/2022] Open
Abstract
The epigenetic modification of chromatin structure and its effect on complex neuronal processes like learning and memory is an emerging field in neuroscience. However, little is known about the "writers" of the neuronal epigenome and how they lay down the basis for proper cognition. Here, we have dissected the neuronal function of the Drosophila euchromatin histone methyltransferase (EHMT), a member of a conserved protein family that methylates histone 3 at lysine 9 (H3K9). EHMT is widely expressed in the nervous system and other tissues, yet EHMT mutant flies are viable. Neurodevelopmental and behavioral analyses identified EHMT as a regulator of peripheral dendrite development, larval locomotor behavior, non-associative learning, and courtship memory. The requirement for EHMT in memory was mapped to 7B-Gal4 positive cells, which are, in adult brains, predominantly mushroom body neurons. Moreover, memory was restored by EHMT re-expression during adulthood, indicating that cognitive defects are reversible in EHMT mutants. To uncover the underlying molecular mechanisms, we generated genome-wide H3K9 dimethylation profiles by ChIP-seq. Loss of H3K9 dimethylation in EHMT mutants occurs at 5% of the euchromatic genome and is enriched at the 5' and 3' ends of distinct classes of genes that control neuronal and behavioral processes that are corrupted in EHMT mutants. Our study identifies Drosophila EHMT as a key regulator of cognition that orchestrates an epigenetic program featuring classic learning and memory genes. Our findings are relevant to the pathophysiological mechanisms underlying Kleefstra Syndrome, a severe form of intellectual disability caused by mutations in human EHMT1, and have potential therapeutic implications. Our work thus provides novel insights into the epigenetic control of cognition in health and disease.
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Affiliation(s)
- Jamie M. Kramer
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Korinna Kochinke
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Merel A. W. Oortveld
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Hendrik Marks
- Radboud University Nijmegen, Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Faculty of Science, Nijmegen, The Netherlands
| | - Daniela Kramer
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Eiko K. de Jong
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Zoltan Asztalos
- Aktogen Ltd., Department of Genetics, University of Cambridge, Cambridge, United Kingdom
- Institute of Biochemistry, Biological Research Center of Hungarian Academy of Sciences, Szeged, Hungary
| | | | - Hendrik G. Stunnenberg
- Radboud University Nijmegen, Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Faculty of Science, Nijmegen, The Netherlands
| | | | | | - Huiqing Zhou
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Hans van Bokhoven
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department of Cognitive Neurosciences, Donders Institute for Brain, Cognition and Behavior; Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- * E-mail: (AS); (HvB)
| | - Annette Schenck
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- * E-mail: (AS); (HvB)
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Plazas-Mayorca MD, Bloom JS, Zeissler U, Leroy G, Young NL, DiMaggio PA, Krugylak L, Schneider R, Garcia BA. Quantitative proteomics reveals direct and indirect alterations in the histone code following methyltransferase knockdown. MOLECULAR BIOSYSTEMS 2010; 6:1719-29. [PMID: 20577673 DOI: 10.1039/c003307c] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Histones are highly conserved proteins that organize cellular DNA. These proteins, especially their N-terminal domains, are adorned with many post-translational modifications (PTMs) such as lysine methylation, which are associated with active or repressed transcriptional states. The lysine methyltransferase G9a and its interaction partner Glp1 can mono- or dimethylate histone H3 on lysine (H3K9me1 or me2); possible cross-talk between these modifications and other PTMs on the same or other histone molecules is currently uncharacterized. In this study, we comprehensively analyze the effects of G9a/Glp1 knockdown on the most abundant histone modifications through both Bottom Up and Middle Down mass spectrometry-based proteomics. In addition to the expected decrease in H3K9me1/me2 we find that other degrees of methylation on K9 are affected by the reduction of G9a/Glp1 activity, particularly when K9 methylation occurs in combination with K14 acetylation. In line with this, an increase in K14 acetylation upon G9a knockdown was observed across all H3 variants (H3.1, H3.2 and H3.3), hinting at the potential existence of a binary switch between K9 methylation and K14 acetylation. Interestingly, we also detect changes in the abundance of other modifications (such as H3K79me2) in response to lowered levels of G9a/Glp1 suggesting histone PTM cross-talk amongst the H3 variants. In contrast, we find that G9a/Glp1 knockdown produces little effect on the levels of histone H4 PTMs, indicating low to no trans-histone PTM crosstalk. Lastly, we determined gene expression profiles of control and G9a/Glp1 knockdown cells, and we find that the G9a/Glp1 knockdown influences several genes, including DNA binding proteins and key factors in chromatin. Our results provide new insights into the intra- and inter- histone cross-regulation of histone K9 methylation and its potential downstream gene targets.
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35
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Lee KS, Yoon J, Park JS, Kang YK. Drosophila G9a is implicated in germ cell development. INSECT MOLECULAR BIOLOGY 2010; 19:131-139. [PMID: 20002223 DOI: 10.1111/j.1365-2583.2009.00955.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In Drosophila ovaries, germline stem cells (GSCs) divide asymmetrically in the germaria to produce daughter GSCs and cystoblasts. Single cystoblasts differentiate to form germline cysts with 16 germline cells, all of which are connected by the fusome, a vesiculated structure critical for oocyte specification. We here show that histone H3K9 methyltransferase dg9a is associated with spectrosome/fusome formation in the germarium; dG9a(13414) mutant ovaries have disorganized spectrosome/fusome in about half the germaria, with reduced levels of hu-li tai shao and alpha-SPECTRIN proteins. We found that the amount of germline cells within cysts was reduced and that oocyte determination often failed in egg chambers of the dG9a(13414) mutant ovaries. These results suggest that a mutation in dG9a gene gives rise to anomalous spectrosome/fusome structures, which in turn lead to faulty germ-cell development in Drosophila ovaries.
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Affiliation(s)
- K-S Lee
- Aging Research Center, KRIBB, 111 Gwahangno, Yuseong-gu, Daejeon 305-806, Korea
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Spindler KD, Hönl C, Tremmel C, Braun S, Ruff H, Spindler-Barth M. Ecdysteroid hormone action. Cell Mol Life Sci 2009; 66:3837-50. [PMID: 19669094 PMCID: PMC11115491 DOI: 10.1007/s00018-009-0112-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 07/16/2009] [Accepted: 07/16/2009] [Indexed: 01/05/2023]
Abstract
Several reviews devoted to various aspects of ecdysone research have been published during the last few years. Therefore, this article concentrates mainly on the considerable progress in ecdysone research observed recently, and will cover the results obtained during the last 2 years. The main emphasis is put on the molecular mode of ecdysteroid receptor-mediated hormone action. Two examples of interaction with other hormonal signalling pathways are described, namely crosstalk with juvenile hormone and insulin. Some selected, recently investigated examples of the multitude of hormonal responses are described. Finally, ecological aspects and some practical applications are discussed.
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Affiliation(s)
- Klaus-Dieter Spindler
- Institute of General Zoology and Endocrinology, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
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Illi B, Colussi C, Grasselli A, Farsetti A, Capogrossi MC, Gaetano C. NO sparks off chromatin: tales of a multifaceted epigenetic regulator. Pharmacol Ther 2009; 123:344-52. [PMID: 19464317 DOI: 10.1016/j.pharmthera.2009.05.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Accepted: 05/11/2009] [Indexed: 10/20/2022]
Abstract
The discovery of nitric oxide (NO) revealed its ambiguous nature, which is related to its pleiotropic activities that control the homeostasis of every organism from bacteria to mammals in several physiological and pathological situations. The wide range of action of NO basically depends on two features: 1) the variety of chemical reactions depending on NO, and 2) the differential cellular responses elicited by distinct NO concentrations. Despite the increasing body of knowledge regarding its chemistry, biology and NO-dependent signaling pathways, little information is available on the nuclear actions of NO in terms of gene expression regulation. Indeed, studies of a putative role for this diatomic compound in regulating chromatin remodeling are still in their infancy. Only recently has the role of NO in epigenetics emerged, and some of its putative epigenetic properties are still only hypothetical. In the present review, we discuss the current evidence for NO-related mechanisms of epigenetic gene expression regulation. We link some of the well known NO chemical reactions and metabolic processes (e.g., S-nitrosylation of thiols, tyrosine nitration, cGMP production) to chromatin modification and address the most recent, striking hypothesis about NO and the control of chromosomes structure.
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Affiliation(s)
- Barbara Illi
- Laboratorio di Biologia Vascolare e Medicina Rigenerativa, Centro Cardiologico Monzino-IRCCS, Milan, Italy
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Egorova KS, Olenkina OM, Kibanov MV, Kalmykova AI, Gvozdev VA, Olenina LV. Genetically Derepressed Nucleoplasmic Stellate Protein in Spermatocytes of D. melanogaster interacts with the catalytic subunit of protein kinase 2 and carries histone-like lysine-methylated mark. J Mol Biol 2009; 389:895-906. [PMID: 19422836 DOI: 10.1016/j.jmb.2009.04.064] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 04/20/2009] [Accepted: 04/27/2009] [Indexed: 11/30/2022]
Abstract
SUMMARY The X-chromosome-linked clusters of the tandemly repeated testis-specific Stellate genes of Drosophila melanogaster, encoding proteins homologous to the regulatory beta-subunit of the protein kinase casein kinase 2 (CK2), are repressed in wild-type males. Derepression of Stellate genes in the absence of the Y chromosome or Y-linked crystal locus (crystal line) causes accumulation of abundant protein crystals in testes and different meiotic abnormalities, which lead to partial or complete male sterility. To understand the cause of abnormalities in chromosome behavior owing to Stellate overexpression, we studied subcellular localization of Stellate proteins by biochemical fractionation and immunostaining of whole testes. We showed that, apart from the known accumulation of Stellate in crystalline form, soluble Stellate was located exclusively in the nucleoplasm, whereas Stellate crystals were located mainly in the cytoplasm. Coimmunoprecipitation experiments revealed that the alpha-subunit of the protein kinase CK2 (CK2alpha) was associated with soluble Stellate. Interaction between soluble Stellate and CK2alpha in the nucleus could lead to modulations in the phosphorylation of nuclear targets of CK2 and abnormalities in the meiotic segregation of chromosomes. We also observed that Stellate underwent lysine methylation and mimicked trimethyl-H3K9 epigenetic modification of histone H3 tail.
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Affiliation(s)
- Ksenia S Egorova
- Institute of Molecular Genetics, Russian Academy of Science, Moscow, Russia
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Multiple SET methyltransferases are required to maintain normal heterochromatin domains in the genome of Drosophila melanogaster. Genetics 2009; 181:1303-19. [PMID: 19189944 DOI: 10.1534/genetics.108.100271] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Methylation of histone H3 lysine 9 (H3K9) is a key feature of silent chromatin and plays an important role in stabilizing the interaction of heterochromatin protein 1 (HP1) with chromatin. Genomes of metazoans such as the fruit fly Drosophila melanogaster generally encode three types of H3K9-specific SET domain methyltransferases that contribute to chromatin homeostasis during the life cycle of the organism. SU(VAR)3-9, dG9a, and dSETDB1 all function in the generation of wild-type H3K9 methylation levels in the Drosophila genome. Two of these enzymes, dSETDB1 and SU(VAR)3-9, govern heterochromatin formation in distinct but overlapping patterns across the genome. H3K9 methylation in the small, heterochromatic fourth chromosome of D. melanogaster is governed mainly by dSETDB1, whereas dSETDB1 and SU(VAR)3-9 function in concert to methylate H3K9 in the pericentric heterochromatin of all chromosomes, with dG9a having little impact in these domains, as shown by monitoring position effect variegation. To understand how these distinct heterochromatin compartments may be differentiated, we examined the developmental timing of dSETDB1 function using a knockdown strategy. dSETDB1 acts to maintain heterochromatin during metamorphosis, at a later stage in development than the reported action of SU(VAR)3-9. Surprisingly, depletion of both of these enzymes has less deleterious effect than depletion of one. These results imply that dSETDB1 acts as a heterochromatin maintenance factor that may be required for the persistence of earlier developmental events normally governed by SU(VAR)3-9. In addition, the genetic interactions between dSETDB1 and Su(var)3-9 mutations emphasize the importance of maintaining the activities of these histone methyltransferases in balance for normal genome function.
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Kato Y, Kato M, Tachibana M, Shinkai Y, Yamaguchi M. Characterization ofDrosophilaG9ain vivoand identification of genetic interactants. Genes Cells 2008; 13:703-22. [DOI: 10.1111/j.1365-2443.2008.01199.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Yoon J, Lee KS, Park JS, Yu K, Paik SG, Kang YK. dSETDB1 and SU(VAR)3-9 sequentially function during germline-stem cell differentiation in Drosophila melanogaster. PLoS One 2008; 3:e2234. [PMID: 18493619 PMCID: PMC2377335 DOI: 10.1371/journal.pone.0002234] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Accepted: 04/11/2008] [Indexed: 11/18/2022] Open
Abstract
Germline-stem cells (GSCs) produce gametes and are thus true “immortal stem cells”. In Drosophila ovaries, GSCs divide asymmetrically to produce daughter GSCs and cystoblasts, and the latter differentiate into germline cysts. Here we show that the histone-lysine methyltransferase dSETDB1, located in pericentric heterochromatin, catalyzes H3-K9 trimethylation in GSCs and their immediate descendants. As germline cysts differentiate into egg chambers, the dSETDB1 function is gradually taken over by another H3-K9-specific methyltransferase, SU(VAR)3–9. Loss-of-function mutations in dsetdb1 or Su(var)3–9 abolish both H3K9me3 and heterochromatin protein-1 (HP1) signals from the anterior germarium and the developing egg chambers, respectively, and cause localization of H3K9me3 away from DNA-dense regions in most posterior germarium cells. These results indicate that dSETDB1 and SU(VAR)3–9 act together with distinct roles during oogenesis, with dsetdb1 being of particular importance due to its GSC-specific function and more severe mutant phenotype.
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Affiliation(s)
- Jeongheon Yoon
- Center for Regenerative Medicine, Korean Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
- Department of Biology, Chungnam National University, Daejon, Korea
| | - Kyu-Sun Lee
- Center for Regenerative Medicine, Korean Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
| | - Jung Sun Park
- Center for Regenerative Medicine, Korean Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
| | - Kweon Yu
- Center for Regenerative Medicine, Korean Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
| | - Sang-Gi Paik
- Department of Biology, Chungnam National University, Daejon, Korea
| | - Yong-Kook Kang
- Center for Regenerative Medicine, Korean Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
- * E-mail:
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Atrophin recruits HDAC1/2 and G9a to modify histone H3K9 and to determine cell fates. EMBO Rep 2008; 9:555-62. [PMID: 18451879 DOI: 10.1038/embor.2008.67] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Revised: 03/27/2008] [Accepted: 03/28/2008] [Indexed: 11/08/2022] Open
Abstract
Atrophin family proteins, including the vertebrate arginine-glutamic acid dipeptide repeats protein (RERE) and Drosophila Atrophin (Atro), constitute a new class of nuclear receptor corepressors. Both RERE and Atro share the ELM2 (EGL-27 and MTA1 homology 2) and SANT (SWI3/ADA2/N-CoR/TFIII-B) domains, which are also present in other important transcriptional cofactors. Here, we report that the SANT domain in RERE binds to the histone methyltransferase G9a, and that both the ELM2 and SANT domains orchestrate molecular events that lead to a stable methylation of histone H3-lysine 9. We establish the physiological relevance of these interactions among Atrophin, G9a, and histone deacetylases 1 and 2 in Drosophila by showing that these proteins localize to overlapping chromosomal loci, and act together to suppress wing vein and melanotic-mass formation. This study not only shows a new function of the SANT domain and establishes its connection with the ELM2 domain, but also implies that a similar strategy is used by other ELM2-SANT proteins to repress gene transcription and to exert biological effects.
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Abstract
Mammalian G9a is a euchromatic histone H3 lysine 9 (H3K9) methyltransferase essential for development. Here, we characterize the Drosophila homolog of G9a, dG9a. We generated a dG9a deletion allele by homologous recombination. Analysis of this allele revealed that, in contrast to recent findings, dG9a is not required for fly viability.
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Kang MY, Lee BB, Kim YH, Chang DK, Kyu Park S, Chun HK, Song SY, Park J, Kim DH. Association of the SUV39H1 histone methyltransferase with the DNA methyltransferase 1 at mRNA expression level in primary colorectal cancer. Int J Cancer 2007; 121:2192-7. [PMID: 17657744 DOI: 10.1002/ijc.22953] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study was aimed at investigating the involvement of the SUV39H1 histone methyltransferase on the epigenetic change of euchromatic promoter in colorectal cancer. We retrospectively analyzed the mRNA levels of SUV39H1 and the promoter methylation of the p14(ARF), p16(INK4a) and HLTF genes as well as the mRNA levels of DNA methyltransferase 1 (DNMT1) in fresh frozen tissues from 219 colorectal cancer patients. The mRNA levels of the SUV39H1 and DNMT1 were assessed via quantitative real-time PCR and the methylation profiles of the CpG islands were determined using methylation-specific PCR. The mRNA levels of SUV39H1 and DNMT1 were elevated in 25% and 42% of 219 colorectal cancers, respectively. The hypermethylation of the p14(ARF), p16(INK4a) and HLTF genes occurred in 36%, 51% and 34% of the patients. The elevated mRNA levels of SUV39H1 were not associated with the hypermethylation of the 3 genes. However, the mRNA levels of DNMT1 were significantly different between patients with elevated mRNA levels of SUV39H1 and those without (1.62 +/- 0.84, 0.91 +/- 0.81, respectively; p = 0.007). Patients with elevated mRNA levels of SUV39H1 showed a higher prevalence of DNMT1 elevation than those without (61 vs. 35%, p = 0.0008). Patients with an elevated mRNA level of SUV39H1 had a 2.71 (95% CI = 1.09-4.48, p = 0.002) times greater risk of an elevated mRNA level of DNMT1, after controlling for age and gender. In conclusion, the present study suggests that SUV39H1 is significantly associated with DNMT1, but not with euchromatic promoter methylation in colorectal cancer.
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Affiliation(s)
- Mi Yeon Kang
- Center for Genome Research, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Korea
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Sasai N, Kato Y, Kimura G, Takeuchi T, Yamaguchi M. The Drosophila jumonji gene encodes a JmjC-containing nuclear protein that is required for metamorphosis. FEBS J 2007; 274:6139-51. [PMID: 17970746 DOI: 10.1111/j.1742-4658.2007.06135.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Jumonji (Jmj) is a transcriptional repressor that plays important roles in the suppression of cell proliferation and development of various tissues in the mouse. To further clarify the roles of Jmj during development and gain insight into mechanisms of Jmj-mediated transcriptional regulation, we have taken advantage of Drosophila as a model organism. Drosophila Jmj (dJmj) shares high homology with mammalian Jmj in the JmjN, JmjC and AT-rich interaction domains, as well as in the N-terminal repression domain. dJmj localizes to hundreds of euchromatic sites but not to chromocenter heterochromatin on salivary gland polytene chromosomes. In addition, dJmj is excluded from regions stained with an antibody against Ser5-phosphorylated RNA polymerase II, suggesting a function of dJmj in transcriptionally inactive chromatin. Loss of djmj results in larval and pupal lethality with phenotypes similar to those observed in mutants of ecdysone-regulated genes, implying the involvement of dJmj in the repression of gene expression in the ecdysone pathway. Transgenic mouse Jmj mostly colocalizes with dJmj and partially rescues the phenotypes of djmj mutants, indicating that dJmj is a functional homolog of mammalian Jmj. Furthermore, mutation in djmj suppresses position effect variegation of the T(2;3)Sb(V) rearrangement. These findings suggest that dJmj controls expression of developmentally important genes through modification of chromatin into a transcriptionally silenced state.
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Affiliation(s)
- Nobuhiro Sasai
- Venture Laboratory, Kyoto Institute of Technology, Japan
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Krauss V. Glimpses of evolution: heterochromatic histone H3K9 methyltransferases left its marks behind. Genetica 2007; 133:93-106. [PMID: 17710556 DOI: 10.1007/s10709-007-9184-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Accepted: 07/19/2007] [Indexed: 01/01/2023]
Abstract
In eukaryotes, histone methylation is an epigenetic mechanism associated with a variety of functions related to gene regulation or genomic stability. Recently analyzed H3K9 methyltransferases (HMTases) as SUV39H1, Clr4p, DIM-5, Su(var)3-9 or SUVH2 are responsible for the establishment of histone H3 lysine 9 methylation (H3K9me), which is intimately connected with heterochromatinization. In this review, available data will be evaluated concerning (1) the phylogenetic distribution of H3K9me as heterochromatin-specific histone modification and its evolutionary stability in relation to other epigenetic marks, (2) known families of H3K9 methyltransferases, (3) their responsibility for the formation of constitutive heterochromatin and (4) the evolution of Su(var)3-9-like and SUVH-like H3K9 methyltransferases. Compilation and parsimony analysis reveal that histone H3K9 methylation is, next to histone deacetylation, the evolutionary most stable heterochromatic mark, which is established by at least two subfamilies of specialized heterochromatic HMTases in almost all studied eukaryotes.
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Affiliation(s)
- Veiko Krauss
- Department of Genetics, Institute for Biology II, University of Leipzig, Johannisallee 21-23, 04103 Leipzig, Germany.
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Seum C, Reo E, Peng H, Rauscher FJ, Spierer P, Bontron S. Drosophila SETDB1 is required for chromosome 4 silencing. PLoS Genet 2007; 3:e76. [PMID: 17500594 PMCID: PMC1866353 DOI: 10.1371/journal.pgen.0030076] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Accepted: 04/03/2007] [Indexed: 01/08/2023] Open
Abstract
Histone H3 lysine 9 (H3K9) methylation is associated with gene repression and heterochromatin formation. In Drosophila, SU(VAR)3–9 is responsible for H3K9 methylation mainly at pericentric heterochromatin. However, the histone methyltransferases responsible for H3K9 methylation at euchromatic sites, telomeres, and at the peculiar Chromosome 4 have not yet been identified. Here, we show that DmSETDB1 is involved in nonpericentric H3K9 methylation. Analysis of two DmSetdb1 alleles generated by homologous recombination, a deletion, and an allele where the 3HA tag is fused to the endogenous DmSetdb1, reveals that this gene is essential for fly viability and that DmSETDB1 localizes mainly at Chromosome 4. It also shows that DmSETDB1 is responsible for some of the H3K9 mono- and dimethyl marks in euchromatin and for H3K9 dimethylation on Chromosome 4. Moreover, DmSETDB1 is required for variegated repression of transgenes inserted on Chromosome 4. This study defines DmSETDB1 as a H3K9 methyltransferase that specifically targets euchromatin and the autosomal Chromosome 4 and shows that it is an essential factor for Chromosome 4 silencing. DNA is the basic unit carrying genetic information. Within the nucleus, DNA is wrapped around an eight-histone complex to form the nucleosome. The nucleosomes and other associated proteins assemble to a higher order structure called chromatin. The histones are mainly globular, excepted for their tails that protrude from the nucleosome core. The amino acids of the histone tails are often modified. For example, several conserved lysine residues can be methylated. Methylation of lysine 9 on histone H3 (H3K9) is important for proper chromatin structure and gene regulation. Here, we characterize Drosophila DmSETDB1 as a histone methyltransferase responsible for H3K9 methylation of the chromosome arms and Chromosome 4. In addition, we show that in the absence of DmSETDB1, silencing of Chromosome 4 is abolished. This study is an important step towards the understanding of the differential chromatin domain specificity and mode of action of H3K9 methyltransferases.
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Affiliation(s)
- Carole Seum
- Department of Zoology and Animal Biology, University of Geneva, Geneva, Switzerland
| | - Emanuela Reo
- Department of Zoology and Animal Biology, University of Geneva, Geneva, Switzerland
| | - Hongzhuang Peng
- The Wistar Institute, Philadelphia, Pennsylvania, United States of America
| | - Frank J Rauscher
- The Wistar Institute, Philadelphia, Pennsylvania, United States of America
| | - Pierre Spierer
- Department of Zoology and Animal Biology, University of Geneva, Geneva, Switzerland
| | - Séverine Bontron
- Department of Zoology and Animal Biology, University of Geneva, Geneva, Switzerland
- * To whom correspondence should be addressed. E-mail:
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