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Vorobyeva NE, Krasnov AN, Erokhin M, Chetverina D, Mazina M. Su(Hw) interacts with Combgap to establish long-range chromatin contacts. Epigenetics Chromatin 2024; 17:17. [PMID: 38773468 PMCID: PMC11106861 DOI: 10.1186/s13072-024-00541-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 05/16/2024] [Indexed: 05/23/2024] Open
Abstract
BACKGROUND Insulator-binding proteins (IBPs) play a critical role in genome architecture by forming and maintaining contact domains. While the involvement of several IBPs in organising chromatin architecture in Drosophila has been described, the specific contribution of the Suppressor of Hairy wings (Su(Hw)) insulator-binding protein to genome topology remains unclear. RESULTS In this study, we provide evidence for the existence of long-range interactions between chromatin bound Su(Hw) and Combgap, which was first characterised as Polycomb response elements binding protein. Loss of Su(Hw) binding to chromatin results in the disappearance of Su(Hw)-Combgap long-range interactions and in a decrease in spatial self-interactions among a subset of Su(Hw)-bound genome sites. Our findings suggest that Su(Hw)-Combgap long-range interactions are associated with active chromatin rather than Polycomb-directed repression. Furthermore, we observe that the majority of transcription start sites that are down-regulated upon loss of Su(Hw) binding to chromatin are located within 2 kb of Combgap peaks and exhibit Su(Hw)-dependent changes in Combgap and transcriptional regulators' binding. CONCLUSIONS This study demonstrates that Su(Hw) insulator binding protein can form long-range interactions with Combgap, Polycomb response elements binding protein, and that these interactions are associated with active chromatin factors rather than with Polycomb dependent repression.
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Affiliation(s)
- Nadezhda E Vorobyeva
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Alexey N Krasnov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Maksim Erokhin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Darya Chetverina
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Marina Mazina
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
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2
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Cornejo KG, Venegas A, Sono MH, Door M, Gutierrez-Ruiz B, Karabedian LB, Nandi SG, Dykhuizen EC, Saha RN. Activity-assembled nBAF complex mediates rapid immediate early gene transcription by regulating RNA Polymerase II productive elongation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.30.573688. [PMID: 38234780 PMCID: PMC10793463 DOI: 10.1101/2023.12.30.573688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Signal-dependent RNA Polymerase II (Pol2) productive elongation is an integral component of gene transcription, including those of immediate early genes (IEGs) induced by neuronal activity. However, it remains unclear how productively elongating Pol2 overcome nucleosomal barriers. Using RNAi, three degraders, and several small molecule inhibitors, we show that the mammalian SWI/SNF complex of neurons (neuronal BAF, or nBAF) is required for activity-induced transcription of neuronal IEGs, including Arc . The nBAF complex facilitates promoter-proximal Pol2 pausing, signal-dependent Pol2 recruitment (loading), and importantly, mediates productive elongation in the gene body via interaction with the elongation complex and elongation-competent Pol2. Mechanistically, Pol2 elongation is mediated by activity-induced nBAF assembly (especially, ARID1A recruitment) and its ATPase activity. Together, our data demonstrate that the nBAF complex regulates several aspects of Pol2 transcription and reveal mechanisms underlying activity-induced Pol2 elongation. These findings may offer insights into human maladies etiologically associated with mutational interdiction of BAF functions.
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3
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Zraly CB, Schultz R, Diaz MO, Dingwall AK. New twists of a TAIL: novel insights into the histone binding properties of a highly conserved PHD finger cluster within the MLR family of H3K4 mono-methyltransferases. Nucleic Acids Res 2023; 51:9672-9689. [PMID: 37638761 PMCID: PMC10570056 DOI: 10.1093/nar/gkad698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 07/19/2023] [Accepted: 08/11/2023] [Indexed: 08/29/2023] Open
Abstract
Enhancer activation by the MLR family of H3K4 mono-methyltransferases requires proper recognition of histones for the deposition of the mono-methyl mark. MLR proteins contain two clusters of PHD zinc finger domains implicated in chromatin regulation. The second cluster is the most highly conserved, preserved as an ancient three finger functional unit throughout evolution. Studies of the isolated 3rd PHD finger within this cluster suggested specificity for the H4 [aa16-20] tail region. We determined the histone binding properties of the full three PHD finger cluster b module (PHDb) from the Drosophila Cmi protein which revealed unexpected recognition of an extended region of H3. Importantly, the zinc finger spacer separating the first two PHDb fingers from the third is critical for proper alignment and coordination among fingers for maximal histone engagement. Human homologs, MLL3 and MLL4, also show conservation of H3 binding, expanding current views of histone recognition for this class of proteins. We further implicate chromatin remodeling by the SWI/SNF complex as a possible mechanism for the accessibility of PHDb to globular regions of histone H3 beyond the tail region. Our results suggest a two-tail histone recognition mechanism by the conserved PHDb domain involving a flexible hinge to promote interdomain coordination.
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Affiliation(s)
- Claudia B Zraly
- Department of Cancer Biology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Richard Schultz
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Manuel O Diaz
- Department of Cancer Biology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Andrew K Dingwall
- Department of Cancer Biology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
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4
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Tilly BC, Chalkley GE, van der Knaap JA, Moshkin YM, Kan TW, Dekkers DH, Demmers JA, Verrijzer CP. In vivo analysis reveals that ATP-hydrolysis couples remodeling to SWI/SNF release from chromatin. eLife 2021; 10:69424. [PMID: 34313222 PMCID: PMC8352592 DOI: 10.7554/elife.69424] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/26/2021] [Indexed: 12/23/2022] Open
Abstract
ATP-dependent chromatin remodelers control the accessibility of genomic DNA through nucleosome mobilization. However, the dynamics of genome exploration by remodelers, and the role of ATP hydrolysis in this process remain unclear. We used live-cell imaging of Drosophila polytene nuclei to monitor Brahma (BRM) remodeler interactions with its chromosomal targets. In parallel, we measured local chromatin condensation and its effect on BRM association. Surprisingly, only a small portion of BRM is bound to chromatin at any given time. BRM binds decondensed chromatin but is excluded from condensed chromatin, limiting its genomic search space. BRM-chromatin interactions are highly dynamic, whereas histone-exchange is limited and much slower. Intriguingly, loss of ATP hydrolysis enhanced chromatin retention and clustering of BRM, which was associated with reduced histone turnover. Thus, ATP hydrolysis couples nucleosome remodeling to remodeler release, driving a continuous transient probing of the genome.
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Affiliation(s)
- Ben C Tilly
- Department of Biochemistry, Rotterdam, Netherlands
| | | | | | | | | | - Dick Hw Dekkers
- Department of Biochemistry, Rotterdam, Netherlands.,Proteomics Center, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Jeroen Aa Demmers
- Department of Biochemistry, Rotterdam, Netherlands.,Proteomics Center, Erasmus University Medical Center, Rotterdam, Netherlands
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5
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In Vivo Silencing of Genes Coding for dTip60 Chromatin Remodeling Complex Subunits Affects Polytene Chromosome Organization and Proper Development in Drosophila melanogaster. Int J Mol Sci 2021; 22:ijms22094525. [PMID: 33926075 PMCID: PMC8123692 DOI: 10.3390/ijms22094525] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 04/17/2021] [Accepted: 04/22/2021] [Indexed: 12/17/2022] Open
Abstract
Chromatin organization is developmentally regulated by epigenetic changes mediated by histone-modifying enzymes and chromatin remodeling complexes. In Drosophila melanogaster, the Tip60 chromatin remodeling complex (dTip60) play roles in chromatin regulation, which are shared by evolutionarily-related complexes identified in animal and plants. Recently, it was found that most subunits previously assigned to the dTip60 complex are shared by two related complexes, DOM-A.C and DOM-B.C, defined by DOM-A and DOM-B isoforms, respectively. In this work, we combined classical genetics, cell biology, and reverse genetics approaches to further investigate the biological roles played during Drosophila melanogaster development by a number of subunits originally assigned to the dTip60 complex.
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6
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Gomathi K, Akshaya N, Srinaath N, Rohini M, Selvamurugan N. Histone acetyl transferases and their epigenetic impact on bone remodeling. Int J Biol Macromol 2020; 170:326-335. [PMID: 33373635 DOI: 10.1016/j.ijbiomac.2020.12.173] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/22/2020] [Accepted: 12/22/2020] [Indexed: 12/13/2022]
Abstract
Bone remodeling is a complex event that maintains bone homeostasis. The epigenetic mechanism of the regulation of bone remodeling has been a major research focus over the past decades. Histone acetylation is an influential post-translational modification in chromatin architecture. Acetylation affects chromatin structure by offering binding signals for reader proteins that harbor acetyl-lysine recognition domains. This review summarizes recent data of histone acetylation in bone remodeling. The crux of this review is the functional role of histone acetyltransferases, the key promoters of histone acetylation. The functional regulation of acetylation via noncoding RNAs in bone remodeling is also discussed. Understanding the principles governing histone acetylation in bone remodeling would lead to the development of better epigenetic therapies for bone diseases.
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Affiliation(s)
- K Gomathi
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
| | - N Akshaya
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
| | - N Srinaath
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
| | - M Rohini
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
| | - N Selvamurugan
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India.
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7
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Onishi R, Sato K, Murano K, Negishi L, Siomi H, Siomi MC. Piwi suppresses transcription of Brahma-dependent transposons via Maelstrom in ovarian somatic cells. SCIENCE ADVANCES 2020; 6:6/50/eaaz7420. [PMID: 33310860 PMCID: PMC7732180 DOI: 10.1126/sciadv.aaz7420] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 10/19/2020] [Indexed: 05/05/2023]
Abstract
Drosophila Piwi associates with PIWI-interacting RNAs (piRNAs) and represses transposons transcriptionally through heterochromatinization; however, this process is poorly understood. Here, we identify Brahma (Brm), the core adenosine triphosphatase of the SWI/SNF chromatin remodeling complex, as a new Piwi interactor, and show Brm involvement in activating transcription of Piwi-targeted transposons before silencing. Bioinformatic analyses indicated that Piwi, once bound to target RNAs, reduced the occupancies of SWI/SNF and RNA polymerase II (Pol II) on target loci, abrogating transcription. Artificial piRNA-driven targeting of Piwi to RNA transcripts enhanced repression of Brm-dependent reporters compared with Brm-independent reporters. This was dependent on Piwi cofactors, Gtsf1/Asterix (Gtsf1), Panoramix/Silencio (Panx), and Maelstrom (Mael), but not Eggless/dSetdb (Egg)-mediated H3K9me3 deposition. The λN-box B-mediated tethering of Mael to reporters repressed Brm-dependent genes in the absence of Piwi, Panx, and Gtsf1. We propose that Piwi, via Mael, can rapidly suppress transcription of Brm-dependent genes to facilitate heterochromatin formation.
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Affiliation(s)
- Ryo Onishi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan
| | - Kaoru Sato
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan
| | - Kensaku Murano
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Lumi Negishi
- Central Laboratory, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo 113-0032, Japan
| | - Haruhiko Siomi
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Mikiko C Siomi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan.
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8
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Magaña-Acosta M, Valadez-Graham V. Chromatin Remodelers in the 3D Nuclear Compartment. Front Genet 2020; 11:600615. [PMID: 33329746 PMCID: PMC7673392 DOI: 10.3389/fgene.2020.600615] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 10/07/2020] [Indexed: 12/15/2022] Open
Abstract
Chromatin remodeling complexes (CRCs) use ATP hydrolysis to maintain correct expression profiles, chromatin stability, and inherited epigenetic states. More than 20 CRCs have been described to date, which encompass four large families defined by their ATPase subunits. These complexes and their subunits are conserved from yeast to humans through evolution. Their activities depend on their catalytic subunits which through ATP hydrolysis provide the energy necessary to fulfill cellular functions such as gene transcription, DNA repair, and transposon silencing. These activities take place at the first levels of chromatin compaction, and CRCs have been recognized as essential elements of chromatin dynamics. Recent studies have demonstrated an important role for these complexes in the maintenance of higher order chromatin structure. In this review, we present an overview of the organization of the genome within the cell nucleus, the different levels of chromatin compaction, and importance of the architectural proteins, and discuss the role of CRCs and how their functions contribute to the dynamics of the 3D genome organization.
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Affiliation(s)
- Mauro Magaña-Acosta
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Viviana Valadez-Graham
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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9
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The mechanisms of action of chromatin remodelers and implications in development and disease. Biochem Pharmacol 2020; 180:114200. [DOI: 10.1016/j.bcp.2020.114200] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/09/2020] [Accepted: 08/12/2020] [Indexed: 02/06/2023]
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10
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Abstract
The Trithorax group (TrxG) of proteins is a large family of epigenetic regulators that form multiprotein complexes to counteract repressive developmental gene expression programmes established by the Polycomb group of proteins and to promote and maintain an active state of gene expression. Recent studies are providing new insights into how two crucial families of the TrxG - the COMPASS family of histone H3 lysine 4 methyltransferases and the SWI/SNF family of chromatin remodelling complexes - regulate gene expression and developmental programmes, and how misregulation of their activities through genetic abnormalities leads to pathologies such as developmental disorders and malignancies.
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11
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Nguyen CT, Tran GB, Nguyen NH. Homeostasis of histone acetylation is critical for auxin signaling and root morphogenesis. PLANT MOLECULAR BIOLOGY 2020; 103:1-7. [PMID: 32088831 DOI: 10.1007/s11103-020-00985-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/20/2020] [Indexed: 05/24/2023]
Abstract
The auxin signaling and root morphogenesis are harmoniously controlled by two counteracted teams including (1) auxin/indole-3-acetic acid (AUX/IAA)-histone deacetylase (HDA) and (2) auxin response factor (ARF)-histone acetyltransferase (HAT). The involvement of histone acetylation in the regulation of transcription was firstly reported a few decades ago. In planta, auxin is the first hormone group that was discovered and it is also the most studied phytohormone. Current studies have elucidated the functions of histone acetylation in the modulation of auxin signaling as well as in the regulation of root morphogenesis under both normal and stress conditions. Based on the recent outcomes, this review is to provide a hierarchical view about the functions of histone acetylation in auxin signaling and root morphogenesis. In this report, we suggest that the auxin signaling must be controlled harmoniously by two counteracted teams including (1) auxin/indole-3-acetic acid (AUX/IAA)-histone deacetylase (HDA) and (2) auxin response factor (ARF)-histone acetyltransferase (HAT). Moreover, the balance in auxin signaling is very critical to contribute to normal root morphogenesis.
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Affiliation(s)
- Cuong Thach Nguyen
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam
| | - Gia-Buu Tran
- Department of Biotechnology, Institute of Biotechnology and Food-Technology, Industrial University of Ho Chi Minh City, 12 Nguyen Van Bao Street, Ward 4, Go Vap District, Ho Chi Minh City, Vietnam
| | - Nguyen Hoai Nguyen
- Faculty of Biotechnology, Ho Chi Minh City Open University, 97 Vo Van Tan Street, District 3, Ho Chi Minh City, Vietnam.
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12
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Hu B, Lin JZ, Yang XB, Sang XT. The roles of mutated SWI/SNF complexes in the initiation and development of hepatocellular carcinoma and its regulatory effect on the immune system: A review. Cell Prolif 2020; 53:e12791. [PMID: 32162380 PMCID: PMC7162795 DOI: 10.1111/cpr.12791] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/13/2020] [Accepted: 02/22/2020] [Indexed: 12/11/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is a primary liver malignancy with a high global prevalence and a dismal prognosis. Studies are urgently needed to examine the molecular pathogenesis and biological characteristics of HCC. Chromatin remodelling, an integral component of the DNA damage response, protects against DNA damage‐induced genome instability and tumorigenesis by triggering the signalling events that activate the interconnected DNA repair pathways. The SWI/SNF complexes are one of the most extensively investigated adenosine triphosphate‐dependent chromatin remodelling complexes, and mutations in genes encoding SWI/SNF subunits are frequently observed in various human cancers, including HCC. The mutated SWI/SNF complex subunits exert dual functions by accelerating or inhibiting HCC initiation and progression. Furthermore, the abnormal SWI/SNF complexes influence the transcription of interferon‐stimulated genes, as well as the differentiation, activation and recruitment of several immune cell types. In addition, they exhibit synergistic effects with immune checkpoint inhibitors in the treatment of diverse tumour types. Therefore, understanding the mutations and deficiencies of the SMI/SNF complexes, together with the associated functional mechanisms, may provide a novel strategy to treat HCC through targeting the related genes or modulating the tumour microenvironment.
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Affiliation(s)
- Bo Hu
- Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jian-Zhen Lin
- Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiao-Bo Yang
- Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xin-Ting Sang
- Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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13
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Gervais L, van den Beek M, Josserand M, Sallé J, Stefanutti M, Perdigoto CN, Skorski P, Mazouni K, Marshall OJ, Brand AH, Schweisguth F, Bardin AJ. Stem Cell Proliferation Is Kept in Check by the Chromatin Regulators Kismet/CHD7/CHD8 and Trr/MLL3/4. Dev Cell 2020; 49:556-573.e6. [PMID: 31112698 PMCID: PMC6547167 DOI: 10.1016/j.devcel.2019.04.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/15/2019] [Accepted: 04/18/2019] [Indexed: 12/13/2022]
Abstract
Chromatin remodeling accompanies differentiation, however, its role in self-renewal is less well understood. We report that in Drosophila, the chromatin remodeler Kismet/CHD7/CHD8 limits intestinal stem cell (ISC) number and proliferation without affecting differentiation. Stem-cell-specific whole-genome profiling of Kismet revealed its enrichment at transcriptionally active regions bound by RNA polymerase II and Brahma, its recruitment to the transcription start site of activated genes and developmental enhancers and its depletion from regions bound by Polycomb, Histone H1, and heterochromatin Protein 1. We demonstrate that the Trithorax-related/MLL3/4 chromatin modifier regulates ISC proliferation, colocalizes extensively with Kismet throughout the ISC genome, and co-regulates genes in ISCs, including Cbl, a negative regulator of Epidermal Growth Factor Receptor (EGFR). Loss of kismet or trr leads to elevated levels of EGFR protein and signaling, thereby promoting ISC self-renewal. We propose that Kismet with Trr establishes a chromatin state that limits EGFR proliferative signaling, preventing tumor-like stem cell overgrowths. Chromatin modifiers Kismet and Trr limit intestinal stem cell proliferation Kismet and Trr colocalize at transcriptionally active regions and co-regulate genes EGFR negative regulator Cbl is a target gene of Kismet and Trr Kismet and Trr limit EGFR signaling in ISCs, preventing tumor-like ISC accumulation
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Affiliation(s)
- Louis Gervais
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France.
| | - Marius van den Beek
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Manon Josserand
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Jérémy Sallé
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Marine Stefanutti
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Carolina N Perdigoto
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Patricia Skorski
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Khallil Mazouni
- Institut Pasteur, Department of Developmental and Stem Cell Biology, Paris 75015, France; CNRS, URA2578, Rue du Dr Roux, Paris 75015, France
| | - Owen J Marshall
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 1QN, UK; Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street Hobart, Tasmania, 7000, Australia
| | - Andrea H Brand
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 1QN, UK
| | - François Schweisguth
- Institut Pasteur, Department of Developmental and Stem Cell Biology, Paris 75015, France; CNRS, URA2578, Rue du Dr Roux, Paris 75015, France
| | - Allison J Bardin
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France.
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14
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Bishop TR, Zhang Y, Erb MA. Pharmacological Modulation of Transcriptional Coregulators in Cancer. Trends Pharmacol Sci 2019; 40:388-402. [PMID: 31078321 PMCID: PMC6746237 DOI: 10.1016/j.tips.2019.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/08/2019] [Accepted: 04/09/2019] [Indexed: 12/14/2022]
Abstract
Upon binding of transcription factors to cis-regulatory DNA sequences, transcriptional coregulators are required for the activation or suppression of chromatin-dependent transcriptional signaling. These coregulators are frequently implicated in oncogenesis via causal roles in dysregulated, malignant transcriptional control and represent one of the fastest-growing target classes in small-molecule drug discovery. However, challenges in targeting coregulators include identifying evidence of cancer-specific genetic dependency, matching the pharmacologically addressable protein fold to a functional role in disease pathology, and achieving the necessary selectivity to exploit a given genetic dependency. We discuss here how recent trends in cancer pharmacology have confronted these challenges, positioning coregulators as tractable targets in the development of new cancer therapies.
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Affiliation(s)
- Timothy R Bishop
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Yuxiang Zhang
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Michael A Erb
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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15
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Rosales-Vega M, Hernández-Becerril A, Murillo-Maldonado JM, Zurita M, Vázquez M. The role of the trithorax group TnaA isoforms in Hox gene expression, and in Drosophila late development. PLoS One 2018; 13:e0206587. [PMID: 30372466 PMCID: PMC6205608 DOI: 10.1371/journal.pone.0206587] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 10/16/2018] [Indexed: 11/18/2022] Open
Abstract
Regulation of developmental gene expression in eukaryotes involves several levels. One of them is the maintenance of gene expression along the life of the animal once it is started by different triggers early in development. One of the questions in the field is when in developmental time, the animal start to use the different maintenance mechanisms. The trithorax group (TrxG) of genes was first characterized as essential for maintaining homeotic gene expression. The TrxG gene tonalli interacts genetically and physically with genes and subunits of the BRAHMA BAP chromatin remodeling complex and encodes TnaA proteins with putative E3 SUMO-ligase activity. In contrast to the phenocritic lethal phase of animals with mutations in other TrxG genes, tna mutant individuals die late in development. In this study we determined the requirements of TnaA for survival at pupal and adult stages, in different tna mutant genotypes where we corroborate the lack of TnaA proteins, and the presence of adult homeotic loss-of-function phenotypes. We also investigated whether the absence of TnaA in haltere and leg larval imaginal discs affects the presence of the homeotic proteins Ultrabithorax and Sex combs reduced respectively by using some of the characterized genotypes and more finely by generating TnaA defective clones induced at different stages of development. We found that, tna is not required for growth or survival of imaginal disc cells and that it is a fine modulator of homeotic gene expression.
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Affiliation(s)
- Marco Rosales-Vega
- Departamento de Fisiología Molecular y Genética del Desarrollo, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Adriana Hernández-Becerril
- Departamento de Fisiología Molecular y Genética del Desarrollo, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Juan Manuel Murillo-Maldonado
- Departamento de Fisiología Molecular y Genética del Desarrollo, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Querétaro, México
| | - Mario Zurita
- Departamento de Fisiología Molecular y Genética del Desarrollo, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Martha Vázquez
- Departamento de Fisiología Molecular y Genética del Desarrollo, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
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16
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Kachaev ZM, Lebedeva LA, Kozlov EN, Toropygin IY, Schedl P, Shidlovskii YV. Paip2 is localized to active promoters and loaded onto nascent mRNA in Drosophila. Cell Cycle 2018; 17:1708-1720. [PMID: 29995569 DOI: 10.1080/15384101.2018.1496738] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Paip2 (Poly(A)-binding protein - interacting protein 2) is a conserved metazoan-specific protein that has been implicated in regulating the translation and stability of mRNAs. However, we have found that Paip2 is not restricted to the cytoplasm but is also found in the nucleus in Drosophila embryos, salivary glands, testes, and tissue culture cells. Nuclear Paip2 is associated with chromatin, and in chromatin immunoprecipitation experiments it maps to the promoter regions of active genes. However, this chromatin association is indirect, as it is RNA-dependent. Thus, Paip2 is one more item in the growing list of translation factors that are recruited to mRNAs co-transcriptionally.
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Affiliation(s)
- Zaur M Kachaev
- a Laboratory of Gene Expression Regulation in Development , Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia
| | - Lyubov A Lebedeva
- a Laboratory of Gene Expression Regulation in Development , Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia
| | - Eugene N Kozlov
- a Laboratory of Gene Expression Regulation in Development , Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia
| | - Ilya Y Toropygin
- d Center of Common Use "Human Proteome" , V.I. Orekhovich Research Institute of Biomedical Chemistry , Moscow , Russia
| | - Paul Schedl
- a Laboratory of Gene Expression Regulation in Development , Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia.,b Department of Molecular Biology , Princeton University , Princeton , NJ , USA
| | - Yulii V Shidlovskii
- a Laboratory of Gene Expression Regulation in Development , Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia.,c Department of Biology and General Genetics , I.M. Sechenov First Moscow State Medical University , Moscow , Russia
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17
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Jordán-Pla A, Yu S, Waldholm J, Källman T, Östlund Farrants AK, Visa N. SWI/SNF regulates half of its targets without the need of ATP-driven nucleosome remodeling by Brahma. BMC Genomics 2018; 19:367. [PMID: 29776334 PMCID: PMC5960078 DOI: 10.1186/s12864-018-4746-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 04/30/2018] [Indexed: 12/14/2022] Open
Abstract
Background Brahma (BRM) is the only catalytic subunit of the SWI/SNF chromatin-remodeling complex of Drosophila melanogaster. The function of SWI/SNF in transcription has long been attributed to its ability to remodel nucleosomes, which requires the ATPase activity of BRM. However, recent studies have provided evidence for a non-catalytic function of BRM in the transcriptional regulation of a few specific genes. Results Here we have used RNA-seq and ChIP-seq to identify the BRM target genes in S2 cells, and we have used a catalytically inactive BRM mutant (K804R) that is unable to hydrolyze ATP to investigate the magnitude of the non-catalytic function of BRM in transcription regulation. We show that 49% of the BRM target genes in S2 cells are regulated through mechanisms that do not require BRM to have an ATPase activity. We also show that the catalytic and non-catalytic mechanisms of SWI/SNF regulation operate on two subsets of genes that differ in promoter architecture and are linked to different biological processes. Conclusions This study shows that the non-catalytic role of SWI/SNF in transcription regulation is far more prevalent than previously anticipated and that the genes that are regulated by SWI/SNF through ATPase-dependent and ATPase-independent mechanisms have specialized roles in different cellular and developmental processes. Electronic supplementary material The online version of this article (10.1186/s12864-018-4746-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Antonio Jordán-Pla
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Simei Yu
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Johan Waldholm
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Thomas Källman
- Department of Medical Biochemistry and Microbiology, Uppsala University, SE-751 23, Uppsala, Sweden
| | - Ann-Kristin Östlund Farrants
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Neus Visa
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden.
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18
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Tsui C, Inouye C, Levy M, Lu A, Florens L, Washburn MP, Tjian R. dCas9-targeted locus-specific protein isolation method identifies histone gene regulators. Proc Natl Acad Sci U S A 2018; 115:E2734-E2741. [PMID: 29507191 PMCID: PMC5866577 DOI: 10.1073/pnas.1718844115] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Eukaryotic gene regulation is a complex process, often coordinated by the action of tens to hundreds of proteins. Although previous biochemical studies have identified many components of the basal machinery and various ancillary factors involved in gene regulation, numerous gene-specific regulators remain undiscovered. To comprehensively survey the proteome directing gene expression at a specific genomic locus of interest, we developed an in vitro nuclease-deficient Cas9 (dCas9)-targeted chromatin-based purification strategy, called "CLASP" (Cas9 locus-associated proteome), to identify and functionally test associated gene-regulatory factors. Our CLASP method, coupled to mass spectrometry and functional screens, can be efficiently adapted for isolating associated regulatory factors in an unbiased manner targeting multiple genomic loci across different cell types. Here, we applied our method to isolate the Drosophila melanogaster histone cluster in S2 cells to identify several factors including Vig and Vig2, two proteins that bind and regulate core histone H2A and H3 mRNA via interaction with their 3' UTRs.
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Affiliation(s)
- Chiahao Tsui
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine Center of Excellence, University of California, Berkeley, CA 94720
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720
| | - Carla Inouye
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine Center of Excellence, University of California, Berkeley, CA 94720
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720
| | - Michaella Levy
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Andrew Lu
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine Center of Excellence, University of California, Berkeley, CA 94720
| | | | - Michael P Washburn
- Stowers Institute for Medical Research, Kansas City, MO 64110
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160
| | - Robert Tjian
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine Center of Excellence, University of California, Berkeley, CA 94720;
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720
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19
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Chromatin state changes during neural development revealed by in vivo cell-type specific profiling. Nat Commun 2017; 8:2271. [PMID: 29273756 PMCID: PMC5741632 DOI: 10.1038/s41467-017-02385-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 11/23/2017] [Indexed: 12/22/2022] Open
Abstract
A key question in developmental biology is how cellular differentiation is controlled during development. While transitions between trithorax-group (TrxG) and polycomb-group (PcG) chromatin states are vital for the differentiation of ES cells to multipotent stem cells, little is known regarding the role of chromatin states during development of the brain. Here we show that large-scale chromatin remodelling occurs during Drosophila neural development. We demonstrate that the majority of genes activated during neuronal differentiation are silent in neural stem cells (NSCs) and occupy black chromatin and a TrxG-repressive state. In neurons, almost all key NSC genes are switched off via HP1-mediated repression. PcG-mediated repression does not play a significant role in regulating these genes, but instead regulates lineage-specific transcription factors that control spatial and temporal patterning in the brain. Combined, our data suggest that forms of chromatin other than canonical PcG/TrxG transitions take over key roles during neural development. While transitions between active and repressive chromatin states are essential for differentiation, little is known regarding their role during development of the brain in Drosophila. Here, the authors investigate the large scale chromatin remodelling taking place during fly neural development.
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20
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Pinzón JH, Reed AR, Shalaby NA, Buszczak M, Rodan AR, Rothenfluh A. Alcohol-Induced Behaviors Require a Subset of Drosophila JmjC-Domain Histone Demethylases in the Nervous System. Alcohol Clin Exp Res 2017; 41:2015-2024. [PMID: 28940624 DOI: 10.1111/acer.13508] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 09/15/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Long-lasting transcriptional changes underlie a number of adaptations that contribute to alcohol use disorders (AUD). Chromatin remodeling, including histone methylation, can confer distinct, long-lasting transcriptional changes, and histone methylases are known to play a role in the development of addiction. Conversely, little is known about the relevance of Jumonji (JmjC) domain-containing demethylases in AUDs. We systematically surveyed the alcohol-induced phenotypes of null mutations in all 13 Drosophila JmjC genes. METHODS We used a collection of JmjC mutants, the majority of which we generated by homologous recombination, and assayed them in the Booze-o-mat to determine their naïve sensitivity to sedation and their tolerance (change in sensitivity upon repeat exposure). Mutants with reproducible phenotypes had their phenotypes rescued with tagged genomic transgenes, and/or phenocopied by nervous system-specific knockdown using RNA interference (RNAi). RESULTS Four of the 13 JmjC genes (KDM3, lid, NO66, and HSPBAP1) showed reproducible ethanol (EtOH) sensitivity phenotypes. Some of the phenotypes were observed across doses, for example, the enhanced EtOH sensitivity of KDM3KO and NO66KO , but others were dose dependent, such as the reduced EtOH sensitivity of HSPBAP1KO , or the enhanced EtOH tolerance of NO66KO . These phenotypes were rescued by their respective genomic transgenes in KDM3KO and NO66KO mutants. While we were unable to rescue lidk mutants, knockdown of lid in the nervous system recapitulated the lidk phenotype, as was observed for KDM3KO and NO66KO RNAi-mediated knockdown. CONCLUSIONS Our study reveals that the Drosophila JmjC-domain histone demethylases Lid, KDM3, NO66, and HSPBAP1 are required for normal EtOH-induced sedation and tolerance. Three of 3 tested of those 4 JmjC genes are required in the nervous system for normal alcohol-induced behavioral responses, suggesting that this gene family is an intriguing avenue for future research.
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Affiliation(s)
- Jorge H Pinzón
- Department of Psychiatry, Southwestern Medical Center, University of Texas, Dallas, Texas.,Molecular Biology, Southwestern Medical Center, University of Texas, Dallas, Texas
| | - Addison R Reed
- Department of Psychiatry, University of Utah, Salt Lake City, Utah
| | - Nevine A Shalaby
- Molecular Biology, Southwestern Medical Center, University of Texas, Dallas, Texas
| | - Michael Buszczak
- Molecular Biology, Southwestern Medical Center, University of Texas, Dallas, Texas
| | - Aylin R Rodan
- Departments of Internal Medicine/Division of Nephrology, Molecular Medicine Program, University of Utah, Salt Lake City, Utah
| | - Adrian Rothenfluh
- Department of Psychiatry, Southwestern Medical Center, University of Texas, Dallas, Texas.,Department of Psychiatry, University of Utah, Salt Lake City, Utah
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21
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Kassis JA, Kennison JA, Tamkun JW. Polycomb and Trithorax Group Genes in Drosophila. Genetics 2017; 206:1699-1725. [PMID: 28778878 PMCID: PMC5560782 DOI: 10.1534/genetics.115.185116] [Citation(s) in RCA: 142] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 05/15/2017] [Indexed: 01/08/2023] Open
Abstract
Polycomb group (PcG) and Trithorax group (TrxG) genes encode important regulators of development and differentiation in metazoans. These two groups of genes were discovered in Drosophila by their opposing effects on homeotic gene (Hox) expression. PcG genes collectively behave as genetic repressors of Hox genes, while the TrxG genes are necessary for HOX gene expression or function. Biochemical studies showed that many PcG proteins are present in two protein complexes, Polycomb repressive complexes 1 and 2, which repress transcription via chromatin modifications. TrxG proteins activate transcription via a variety of mechanisms. Here we summarize the large body of genetic and biochemical experiments in Drosophila on these two important groups of genes.
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Affiliation(s)
- Judith A Kassis
- Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
| | - James A Kennison
- Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
| | - John W Tamkun
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, California 95064
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22
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Characterization of joining sites of a viral histone H4 on host insect chromosomes. PLoS One 2017; 12:e0177066. [PMID: 28486493 PMCID: PMC5423620 DOI: 10.1371/journal.pone.0177066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/22/2017] [Indexed: 12/28/2022] Open
Abstract
A viral histone H4 (CpBV-H4) is encoded in a polydnavirus, Cotesia plutellae bracovirus (CpBV). It plays a crucial role in parasitism of an endoparasitoid wasp, C. plutellae, against diamondback moth, Plutella xylostella, by altering host gene expression in an epigenetic mode by its N-terminal tail after joining host nucleosomes. Comparative transcriptomic analysis between parasitized and nonparasitized P. xylostella by RNA-Seq indicated that 1,858 genes were altered at more than two folds in expression levels at late parasitic stage, including 877 up-regulated genes and 981 down-regulated genes. Among parasitic factors altering host gene expression, CpBV-H4 alone explained 16.3% of these expressional changes. To characterize the joining sites of CpBV-H4 on host chromosomes, ChIP-Seq (chromatin immunoprecipitation followed by deep sequencing) was applied to chromatins extracted from parasitized larvae. It identified specific 538 ChIP targets. Joining sites were rich (60.2%) in AT sequence. Almost 40% of ChIP targets included short nucleotide repeat sequences presumably recognizable by transcriptional factors and chromatin remodeling factors. To further validate these CpBV-H4 targets, CpBV-H4 was transiently expressed in nonparasitized host at late larval stage and subjected to ChIP-Seq. Two kinds of ChIP-Seqs shared 51 core joining sites. Common targets were close (within 1 kb) to genes regulated at expression levels by CpBV-H4. However, other host genes not close to CpBV-H4 joining sites were also regulated by CpBV-H4. These results indicate that CpBV-H4 joins specific chromatin regions of P. xylostella and controls about one sixth of the total host genes that were regulated by C. plutellae parasitism in an epigenetic mode.
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23
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Monribot-Villanueva J, Zurita M, Vázquez M. Developmental transcriptional regulation by SUMOylation, an evolving field. Genesis 2017; 55. [PMID: 27935206 DOI: 10.1002/dvg.23009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/29/2016] [Accepted: 11/29/2016] [Indexed: 02/05/2023]
Abstract
SUMOylation is a reversible post-translational protein modification that affects the intracellular localization, stability, activity, and interactions of its protein targets. The SUMOylation pathway influences several nuclear and cytoplasmic processes. The expression of many genes, in particular those involved in development is finely tuned in space and time by several groups of proteins. There is growing evidence that transcriptional regulation mechanisms involve direct SUMOylation of transcriptional-related proteins such as initiation and elongation factors, and subunits of chromatin modifier and remodeling complexes originally described as members of the trithorax and Polycomb groups in Drosophila. Therefore, it is being unveiled that SUMOylation has a role in both, gene silencing and gene activation mechanisms. The goal of this review is to discuss the information on how SUMO modification in components of these multi-subunit complexes may have an effect in genome architecture and function and, therefore, in the regulation of gene expression in time and space.
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Affiliation(s)
- Juan Monribot-Villanueva
- Departamento de Fisiología Molecular y Genética del Desarrollo, Instituto de Biotecnología-Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Mario Zurita
- Departamento de Fisiología Molecular y Genética del Desarrollo, Instituto de Biotecnología-Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Martha Vázquez
- Departamento de Fisiología Molecular y Genética del Desarrollo, Instituto de Biotecnología-Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
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Hong ST, Choi KW. Antagonistic roles of Drosophila Tctp and Brahma in chromatin remodelling and stabilizing repeated sequences. Nat Commun 2016; 7:12988. [PMID: 27687497 PMCID: PMC5056459 DOI: 10.1038/ncomms12988] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 08/24/2016] [Indexed: 12/30/2022] Open
Abstract
Genome stability is essential for all organisms. Translationally controlled tumour protein (TCTP) is a conserved protein associated with cancers. TCTP is involved in multiple intracellular functions, but its role in transcription and genome stability is poorly understood. Here, we demonstrate new functions of Drosophila TCTP (Tctp) in transcription and the stability of repeated sequences (rDNA and pericentromeric heterochromatin). Tctp binds Brahma (Brm) chromatin remodeler to negatively modulate its activity. Tctp mutants show abnormally high levels of transcription in a large set of genes and transposons. These defects are ameliorated by brm mutations. Furthermore, Tctp promotes the stability of repeated sequences by opposing the Brm function. Additional regulation of pericentromeric heterochromatin by Tctp is mediated by su(var)3-9 transcriptional regulation. Altogether, Tctp regulates transcription and the stability of repeated sequences by antagonizing excess Brm activity. This study provides insights into broader nuclear TCTP functions for the maintenance of genome stability. Genome stability is important for normal cellular function. Here, Hong and Choi show that translationally controlled tumour protein (TCTP) in Drosophila regulates pericentromeric chromatin remodelling and transcription via negatively regulating a chromatin remodeler Brahma.
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Affiliation(s)
- Sung-Tae Hong
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Korea
| | - Kwang-Wook Choi
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Korea
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Li X, Yang F, Chen H, Deng B, Li X, Xi R. Control of germline stem cell differentiation by Polycomb and Trithorax group genes in the niche microenvironment. Development 2016; 143:3449-3458. [PMID: 27510973 DOI: 10.1242/dev.137638] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/29/2016] [Indexed: 12/30/2022]
Abstract
Polycomb and Trithorax group (PcG and TrxG) genes function to regulate gene transcription by maintaining a repressive or active chromatin state, respectively. This antagonistic activity is important for body patterning during embryonic development, but whether this function module has a role in adult tissues is unclear. Here, we report that in the Drosophila ovary, disruption of the Polycomb repressive complex 1 (PRC1), specifically in the supporting escort cells, causes blockage of cystoblast differentiation and germline stem cell-like tumor formation. Tumors are caused by derepression of decapentaplegic (dpp), which prevents cystoblast differentiation. Interestingly, activation of dpp in escort cells requires the function of the TrxG gene brahma (brm), suggesting that loss of PRC1 in escort cells causes Brm-dependent dpp expression. Our study suggests a requirement for balanced activity between PcG and TrxG in an adult stem cell niche, and disruption of this balance could lead to the loss of tissue homeostasis and tumorigenesis.
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Affiliation(s)
- Xuewen Li
- College of Biological Sciences, China Agricultural University, Beijing 100193, China National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Fu Yang
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Hongyan Chen
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Bowen Deng
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Xinghua Li
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Rongwen Xi
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
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26
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Hodges C, Kirkland JG, Crabtree GR. The Many Roles of BAF (mSWI/SNF) and PBAF Complexes in Cancer. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a026930. [PMID: 27413115 DOI: 10.1101/cshperspect.a026930] [Citation(s) in RCA: 274] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
During the last decade, a host of epigenetic mechanisms were found to contribute to cancer and other human diseases. Several genomic studies have revealed that ∼20% of malignancies have alterations of the subunits of polymorphic BRG-/BRM-associated factor (BAF) and Polybromo-associated BAF (PBAF) complexes, making them among the most frequently mutated complexes in cancer. Recurrent mutations arise in genes encoding several BAF/PBAF subunits, including ARID1A, ARID2, PBRM1, SMARCA4, and SMARCB1 These subunits share some degree of conservation with subunits from related adenosine triphosphate (ATP)-dependent chromatin remodeling complexes in model organisms, in which a large body of work provides insight into their roles in cancer. Here, we review the roles of BAF- and PBAF-like complexes in these organisms, and relate these findings to recent discoveries in cancer epigenomics. We review several roles of BAF and PBAF complexes in cancer, including transcriptional regulation, DNA repair, and regulation of chromatin architecture and topology. More recent results highlight the need for new techniques to study these complexes.
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Affiliation(s)
- Courtney Hodges
- Departments of Pathology, Developmental Biology, and Genetics, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305
| | - Jacob G Kirkland
- Departments of Pathology, Developmental Biology, and Genetics, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305
| | - Gerald R Crabtree
- Departments of Pathology, Developmental Biology, and Genetics, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305
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27
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Kumar S, Venkata P, Kim Y. Suppressive activity of a viral histone H4 against two host chromatin remodelling factors: lysine demethylase and SWI/SNF. J Gen Virol 2016; 97:2780-2796. [PMID: 27443988 DOI: 10.1099/jgv.0.000560] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Histone H4, a nucleosome subunit in eukaryotes, plays crucial roles in DNA package and regulation of gene expression through covalent modification. A viral histone H4 encoded in Cotesia plutellae bracovirus (CpBV), a polydnavirus, is called CpBV-H4. It is highly homologous to other histone H4 proteins excepting 38 extra amino acid residues in the N terminus. CpBV-H4 can form octamer with other histone subunits and alter host gene expression. In this study, CpBV-H4 was transiently expressed in a natural host (Plutella xylostella) and its suppressive activity on host gene expression was evaluated by the suppressive subtractive hybridization (SSH) technique. The SSH targets down-regulated by CpBV-H4 were read with the 454 pyrosequencing platform and annotated using the genome of P. xylostella. The down-regulated genes (610 contigs) were annotated in most functional categories based on gene ontology. Among these SSH targets, 115 genes were functionally distinct, including two chromatin remodelling factors: a lysine-specific demethylase (Px-KDM) and a chromatin remodelling complex [Px-SWI/SNF (SWItch/Sucrose Non-Fermentable)]. Px-KDM was highly expressed in all tested tissues during the entire larval period. Suppression of Px-KDM expression by specific RNA interference (RNAi) significantly (P<0.05) reduced haemocyte nodule formation in response to immune challenge and impaired both larval and pupal development. Px-SWI/SNF was expressed in all developmental stages. Suppression of Px-SWI/SNF expression by RNAi reduced cellular immune response and interfered with adult metamorphosis. These results suggest that CpBV-H4 can alter host gene expression by interfering with chromatin modification and remodelling factors in addition to its direct epigenetic control activity.
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Affiliation(s)
- Sunil Kumar
- Department of Bioresource Sciences, Andong National University, Andong 36729, Republic of Korea
| | - Prasad Venkata
- Department of Bioresource Sciences, Andong National University, Andong 36729, Republic of Korea
| | - Yonggyun Kim
- Department of Bioresource Sciences, Andong National University, Andong 36729, Republic of Korea
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Identification of Novel Regulators of the JAK/STAT Signaling Pathway that Control Border Cell Migration in the Drosophila Ovary. G3-GENES GENOMES GENETICS 2016; 6:1991-2002. [PMID: 27175018 PMCID: PMC4938652 DOI: 10.1534/g3.116.028100] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) signaling pathway is an essential regulator of cell migration both in mammals and fruit flies. Cell migration is required for normal embryonic development and immune response but can also lead to detrimental outcomes, such as tumor metastasis. A cluster of cells termed “border cells” in the Drosophila ovary provides an excellent example of a collective cell migration, in which two different cell types coordinate their movements. Border cells arise within the follicular epithelium and are required to invade the neighboring cells and migrate to the oocyte to contribute to a fertilizable egg. Multiple components of the STAT signaling pathway are required during border cell specification and migration; however, the functions and identities of other potential regulators of the pathway during these processes are not yet known. To find new components of the pathway that govern cell invasiveness, we knocked down 48 predicted STAT modulators using RNAi expression in follicle cells, and assayed defective cell movement. We have shown that seven of these regulators are involved in either border cell specification or migration. Examination of the epistatic relationship between candidate genes and Stat92E reveals that the products of two genes, Protein tyrosine phosphatase 61F (Ptp61F) and brahma (brm), interact with Stat92E during both border cell specification and migration.
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29
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Ramachandran S, Henikoff S. Transcriptional Regulators Compete with Nucleosomes Post-replication. Cell 2016; 165:580-92. [PMID: 27062929 PMCID: PMC4855302 DOI: 10.1016/j.cell.2016.02.062] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 12/08/2015] [Accepted: 02/24/2016] [Indexed: 10/22/2022]
Abstract
Every nucleosome across the genome must be disrupted and reformed when the replication fork passes, but how chromatin organization is re-established following replication is unknown. To address this problem, we have developed Mapping In vivo Nascent Chromatin with EdU and sequencing (MINCE-seq) to characterize the genome-wide location of nucleosomes and other chromatin proteins behind replication forks at high temporal and spatial resolution. We find that the characteristic chromatin landscape at Drosophila promoters and enhancers is lost upon replication. The most conspicuous changes are at promoters that have high levels of RNA polymerase II (RNAPII) stalling and DNA accessibility and show specific enrichment for the BRM remodeler. Enhancer chromatin is also disrupted during replication, suggesting a role for transcription factor (TF) competition in nucleosome re-establishment. Thus, the characteristic nucleosome landscape emerges from a uniformly packaged genome by the action of TFs, RNAPII, and remodelers minutes after replication fork passage.
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Affiliation(s)
- Srinivas Ramachandran
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Howard Hughes Medical Institute, Seattle, WA 98109, USA
| | - Steven Henikoff
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Howard Hughes Medical Institute, Seattle, WA 98109, USA.
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30
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Fishilevich E, Vélez AM, Khajuria C, Frey MLF, Hamm RL, Wang H, Schulenberg GA, Bowling AJ, Pence HE, Gandra P, Arora K, Storer NP, Narva KE, Siegfried BD. Use of chromatin remodeling ATPases as RNAi targets for parental control of western corn rootworm (Diabrotica virgifera virgifera) and Neotropical brown stink bug (Euschistus heros). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2016; 71:58-71. [PMID: 26873291 DOI: 10.1016/j.ibmb.2016.02.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 02/04/2016] [Accepted: 02/04/2016] [Indexed: 06/05/2023]
Abstract
RNA interference (RNAi) is a gene silencing mechanism that is present in animals and plants and is triggered by double stranded RNA (dsRNA) or small interfering RNA (siRNA), depending on the organism. In the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), RNAi can be achieved by feeding rootworms dsRNA added to artificial diet or plant tissues transformed to express dsRNA. The effect of RNAi depends on the targeted gene function and can range from an absence of phenotypic response to readily apparent responses, including lethality. Furthermore, RNAi can directly affect individuals that consume dsRNA or the effect may be transferred to the next generation. Our previous work described the potential use of genes involved in embryonic development as a parental RNAi technology for the control of WCR. In this study, we describe the use of chromatin-remodeling ATPases as target genes to achieve parental gene silencing in two insect pests, a coleopteran, WCR, and a hemipteran, the Neotropical brown stink bug, Euschistus heros Fabricius (Hemiptera: Pentatomidae). Our results show that dsRNA targeting chromatin-remodeling ATPase transcripts, brahma, mi-2, and iswi strongly reduced the fecundity of the exposed females in both insect species. Additionally, knockdown of chd1 reduced the fecundity of E. heros.
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Affiliation(s)
- Elane Fishilevich
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN, United States
| | - Ana M Vélez
- University of Nebraska, Department of Entomology, 103 Entomology Hall, Lincoln, NE 68583-0816, United States
| | - Chitvan Khajuria
- University of Nebraska, Department of Entomology, 103 Entomology Hall, Lincoln, NE 68583-0816, United States
| | - Meghan L F Frey
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN, United States
| | - Ronda L Hamm
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN, United States
| | - Haichuan Wang
- University of Nebraska, Department of Entomology, 103 Entomology Hall, Lincoln, NE 68583-0816, United States
| | | | - Andrew J Bowling
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN, United States
| | - Heather E Pence
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN, United States
| | - Premchand Gandra
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN, United States
| | - Kanika Arora
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN, United States
| | - Nicholas P Storer
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN, United States
| | - Kenneth E Narva
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN, United States
| | - Blair D Siegfried
- Entomology and Nematology Department, Charles Steinmetz Hall, University of Florida, P.O. Box 110620, Gainesville, FL 32611-0620, United States.
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An RNAi-Based Candidate Screen for Modifiers of the CHD1 Chromatin Remodeler and Assembly Factor in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2015; 6:245-54. [PMID: 26596648 PMCID: PMC4751545 DOI: 10.1534/g3.115.021691] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The conserved chromatin remodeling and assembly factor CHD1 (chromodomains, helicase, DNA-binding domain) is present at active genes where it participates in histone turnover and recycling during transcription. In order to gain a more complete understanding of the mechanism of action of CHD1 during development, we created a novel genetic assay in Drosophila melanogaster to evaluate potential functional interactions between CHD1 and other chromatin factors. We found that overexpression of CHD1 results in defects in wing development and utilized this fully penetrant and reliable phenotype to conduct a small-scale RNAi-based candidate screen to identify genes that functionally interact with chd1 in vivo. Our results indicate that CHD1 may act in opposition to other remodeling factors, including INO80, and that the recruitment of CHD1 to active genes by RTF1 is conserved in flies.
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Khajuria C, Vélez AM, Rangasamy M, Wang H, Fishilevich E, Frey MLF, Carneiro NP, Gandra P, Narva KE, Siegfried BD. Parental RNA interference of genes involved in embryonic development of the western corn rootworm, Diabrotica virgifera virgifera LeConte. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 63:54-62. [PMID: 26005118 DOI: 10.1016/j.ibmb.2015.05.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 05/09/2015] [Accepted: 05/16/2015] [Indexed: 06/04/2023]
Abstract
RNA interference (RNAi) is being developed as a potential tool for insect pest management and one of the most likely target pest species for transgenic plants that express double stranded RNA (dsRNA) is the western corn rootworm. Thus far, most genes proposed as targets for RNAi in rootworm cause lethality in the larval stage. In this study, we describe RNAi-mediated knockdown of two developmental genes, hunchback (hb) and brahma (brm), in the western corn rootworm delivered via dsRNA fed to adult females. dsRNA feeding caused a significant decrease in hb and brm transcripts in the adult females. Although total oviposition was not significantly affected, there was almost complete absence of hatching in the eggs collected from females exposed to dsRNA for either gene. These results confirm that RNAi is systemic in nature for western corn rootworms. These results also indicate that hunchback and brahma play important roles in rootworm embryonic development and could provide useful RNAi targets in adult rootworms to prevent crop injury by impacting the population of larval progeny of exposed adults. The ability to deliver dsRNA in a trans-generational manner by feeding to adult rootworms may offer an additional approach to utilizing RNAi for rootworm pest management. The potential to develop parental RNAi technology targeting progeny of adult rootworms in combination with Bt proteins or dsRNA lethal to larvae may increase opportunities to develop sustainable approaches to rootworm management involving RNAi technologies for rootworm control.
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Affiliation(s)
- Chitvan Khajuria
- University of Nebraska, Department of Entomology, 103 Entomology Hall, Lincoln, NE 68583-0816, United States
| | - Ana M Vélez
- University of Nebraska, Department of Entomology, 103 Entomology Hall, Lincoln, NE 68583-0816, United States
| | - Murugesan Rangasamy
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN 46268, United States
| | - Haichuan Wang
- University of Nebraska, Department of Entomology, 103 Entomology Hall, Lincoln, NE 68583-0816, United States
| | - Elane Fishilevich
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN 46268, United States
| | - Meghan L F Frey
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN 46268, United States
| | | | - Premchand Gandra
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN 46268, United States
| | - Kenneth E Narva
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN 46268, United States
| | - Blair D Siegfried
- University of Nebraska, Department of Entomology, 103 Entomology Hall, Lincoln, NE 68583-0816, United States.
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33
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Abstract
Parent-specific gene expression (PSGE) is little known outside of mammals and plants. PSGE occurs when the expression level of a gene depends on whether an allele was inherited from the mother or the father. Kin selection theory predicts that there should be extensive PSGE in social insects because social insect parents can gain inclusive fitness benefits by silencing parental alleles in female offspring. We searched for evidence of PSGE in honey bees using transcriptomes from reciprocal crosses between European and Africanized strains. We found 46 transcripts with significant parent-of-origin effects on gene expression, many of which overexpressed the maternal allele. Interestingly, we also found a large proportion of genes showing a bias toward maternal alleles in only one of the reciprocal crosses. These results indicate that PSGE may occur in social insects. The nonreciprocal effects could be largely driven by hybrid incompatibility between these strains. Future work will help to determine if these are indeed parent-of-origin effects that can modulate inclusive fitness benefits.
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34
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Zhu Y, Li D, Wang Y, Pei C, Liu S, Zhang L, Yuan Z, Zhang P. Brahma regulates the Hippo pathway activity through forming complex with Yki-Sd and regulating the transcription of Crumbs. Cell Signal 2014; 27:606-13. [PMID: 25496831 DOI: 10.1016/j.cellsig.2014.12.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 11/16/2014] [Accepted: 12/01/2014] [Indexed: 01/24/2023]
Abstract
The Hippo signaling pathway restricts organ size by inactivating the Yorkie (Yki)/Yes-associated protein (YAP) family proteins. The oncogenic Yki/YAP transcriptional coactivator family promotes tissue growth by activating target gene transcription, but the regulation of Yki/YAP activation remains elusive. In mammalian cells, we identified Brg1, a major subunit of chromatin-remodeling SWI/SNF family proteins, which interacts with YAP. This finding led us to investigate the in vivo functional interaction of Yki and Brahma (Brm), the Drosophila homolog of Brg1. We found that Brm functions at the downstream of Hippo pathway and interacts with Yki and Scalloped (Sd) to promotes Yki-dependent transcription and tissue growth. Furthermore, we demonstrated that Brm is required for the Crumbs (Crb) dysregulation-induced Yki activation. Interestingly, we also found that crb is a downstream target of Yki-Brm complex. Brm physically binds to the promoter of crb and regulates its transcription through Yki. Together, we showed that Brm functions as a critical regulator of Hippo signaling during tissue growth and plays an important role in the feedback loop between Crb and Yki.
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Affiliation(s)
- Ye Zhu
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Dong Li
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian 116044, China
| | - Yadong Wang
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Chunli Pei
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Song Liu
- Department of Respiratory Medicine, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Lei Zhang
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Zengqiang Yuan
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Peng Zhang
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
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35
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Abstract
Gene expression frequently requires chromatin-remodeling complexes, and it is assumed that these complexes have common gene targets across cell types. Contrary to this belief, we show by genome-wide expression profiling that Bptf, an essential and unique subunit of the nucleosome-remodeling factor (NURF), predominantly regulates the expression of a unique set of genes between diverse cell types. Coincident with its functions in gene expression, we observed that Bptf is also important for regulating nucleosome occupancy at nucleosome-free regions (NFRs), many of which are located at sites occupied by the multivalent factors Ctcf and cohesin. NURF function at Ctcf binding sites could be direct, because Bptf occupies Ctcf binding sites in vivo and has physical interactions with CTCF and the cohesin subunit SA2. Assays of several Ctcf binding sites using reporter assays showed that their regulatory activity requires Bptf in two different cell types. Focused studies at H2-K1 showed that Bptf regulates the ability of Klf4 to bind near an upstream Ctcf site, possibly influencing gene expression. In combination, these studies demonstrate that gene expression as regulated by NURF occurs partly through physical and functional interactions with the ubiquitous and multivalent factors Ctcf and cohesin.
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36
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Kingston RE, Tamkun JW. Transcriptional regulation by trithorax-group proteins. Cold Spring Harb Perspect Biol 2014; 6:a019349. [PMID: 25274705 DOI: 10.1101/cshperspect.a019349] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The trithorax group of genes (trxG) was identified in mutational screens that examined developmental phenotypes and suppression of Polycomb mutant phenotypes. The protein products of these genes are primarily involved in gene activation, although some can also have repressive effects. There is no central function for these proteins. Some move nucleosomes about on the genome in an ATP-dependent manner, some covalently modify histones such as methylating lysine 4 of histone H3, and some directly interact with the transcription machinery or are a part of that machinery. It is interesting to consider why these specific members of large families of functionally related proteins have strong developmental phenotypes.
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Affiliation(s)
- Robert E Kingston
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - John W Tamkun
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California 95064
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37
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Disruption of hSWI/SNF complexes in T cells by WAS mutations distinguishes X-linked thrombocytopenia from Wiskott-Aldrich syndrome. Blood 2014; 124:3409-19. [PMID: 25253772 DOI: 10.1182/blood-2014-07-587642] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Wiskott-Aldrich syndrome (WAS), an immunodeficiency disorder, and X-linked thrombocytopenia (XLT), a bleeding disorder, both arise from nonsynonymous mutations in WAS, which encodes a hematopoietic-specific WASp. Intriguingly, XLT evolves into WAS in some patients but not in others; yet the biological basis for this cross-phenotype (CP) effect remains unclear. Using human T-helper (TH) cells expressing different disease-causing WAS mutations, we demonstrated that hSWI/SNF-like complexes require nuclear-WASp to execute their chromatin-remodeling activity at promoters of WASp-target, immune function genes during TH1 differentiation. Hot-spot WAS mutations Thr45Met and Arg86Cys, which result in XLT-to-WAS disease progression, impair recruitment of hBRM- but not BRG1-enriched BAF complexes to IFNG and TBX21 promoters. Moreover, promoter enrichment of histone H2A.Z and its catalyzing enzyme EP400 are both impaired. Consequently, activation of Notch signaling, a hBRM-regulated event, and its downstream effector NF-κB are both compromised, along with decreased accessibility of nucleosomal DNA and inefficient transcription-elongation of WASp-target TH1 genes. In contrast, patient mutations Ala236Gly and Arg477Lys that manifest in XLT without progressing to WAS do not disrupt chromatin remodeling or transcriptional reprogramming of TH1 genes. Our study defines an indispensable relationship between nuclear-WASp- and hSWI/SNF-complexes in gene activation and reveals molecular distinctions in TH cells that might contribute to disease severity in the XLT/WAS clinical spectrum.
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38
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Bonnay F, Nguyen XH, Cohen-Berros E, Troxler L, Batsche E, Camonis J, Takeuchi O, Reichhart JM, Matt N. Akirin specifies NF-κB selectivity of Drosophila innate immune response via chromatin remodeling. EMBO J 2014; 33:2349-62. [PMID: 25180232 PMCID: PMC4253524 DOI: 10.15252/embj.201488456] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The network of NF-κB-dependent transcription that activates both pro- and anti-inflammatory genes in mammals is still unclear. As NF-κB factors are evolutionarily conserved, we used Drosophila to understand this network. The NF-κB transcription factor Relish activates effector gene expression following Gram-negative bacterial immune challenge. Here, we show, using a genome-wide approach, that the conserved nuclear protein Akirin is a NF-κB co-factor required for the activation of a subset of Relish-dependent genes correlating with the presence of H3K4ac epigenetic marks. A large-scale unbiased proteomic analysis revealed that Akirin orchestrates NF-κB transcriptional selectivity through the recruitment of the Osa-containing-SWI/SNF-like Brahma complex (BAP). Immune challenge in Drosophila shows that Akirin is required for the transcription of a subset of effector genes, but dispensable for the transcription of genes that are negative regulators of the innate immune response. Therefore, Akirins act as molecular selectors specifying the choice between subsets of NF-κB target genes. The discovery of this mechanism, conserved in mammals, paves the way for the establishment of more specific and less toxic anti-inflammatory drugs targeting pro-inflammatory genes.
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Affiliation(s)
- François Bonnay
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
| | - Xuan-Hung Nguyen
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
| | - Eva Cohen-Berros
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
| | - Laurent Troxler
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
| | - Eric Batsche
- Département de Biologie du Développement, Institut Pasteur, CNRS URA2578, Unité de Régulation Epigénétique, Paris, France
| | | | - Osamu Takeuchi
- Laboratory of Infection and Prevention, Institute for Virus Research Kyoto University CREST, JST, Sakyo-ku, Kyoto, Japan
| | - Jean-Marc Reichhart
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
| | - Nicolas Matt
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
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39
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Banreti A, Hudry B, Sass M, Saurin AJ, Graba Y. Hox proteins mediate developmental and environmental control of autophagy. Dev Cell 2014; 28:56-69. [PMID: 24389064 DOI: 10.1016/j.devcel.2013.11.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Revised: 09/06/2013] [Accepted: 11/27/2013] [Indexed: 11/16/2022]
Abstract
Hox genes encode evolutionarily conserved transcription factors, providing positional information used for differential morphogenesis along the anteroposterior axis. Here, we show that Drosophila Hox proteins are potent repressors of the autophagic process. In inhibiting autophagy, Hox proteins display no apparent paralog specificity and do not provide positional information. Instead, they impose temporality on developmental autophagy and act as effectors of environmental signals in starvation-induced autophagy. Further characterization establishes that temporality is controlled by Pontin, a facultative component of the Brahma chromatin remodeling complex, and that Hox proteins impact on autophagy by repressing the expression of core components of the autophagy machinery. Finally, the potential of central and posterior mouse Hox proteins to inhibit autophagy in Drosophila and in vertebrate COS-7 cells indicates that regulation of autophagy is an evolutionary conserved feature of Hox proteins.
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Affiliation(s)
- Agnes Banreti
- CNRS, Aix Marseille Université, IBDML, UMR 7288, Campus de Luminy, Marseille, cedex 09, 13288, France; Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, 1117, Hungary.
| | - Bruno Hudry
- CNRS, Aix Marseille Université, IBDML, UMR 7288, Campus de Luminy, Marseille, cedex 09, 13288, France
| | - Miklos Sass
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, 1117, Hungary
| | - Andrew J Saurin
- CNRS, Aix Marseille Université, IBDML, UMR 7288, Campus de Luminy, Marseille, cedex 09, 13288, France
| | - Yacine Graba
- CNRS, Aix Marseille Université, IBDML, UMR 7288, Campus de Luminy, Marseille, cedex 09, 13288, France.
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40
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Dorighi KM, Tamkun JW. The trithorax group proteins Kismet and ASH1 promote H3K36 dimethylation to counteract Polycomb group repression in Drosophila. Development 2013; 140:4182-92. [PMID: 24004944 DOI: 10.1242/dev.095786] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Members of the Polycomb group of repressors and trithorax group of activators maintain heritable states of transcription by modifying nucleosomal histones or remodeling chromatin. Although tremendous progress has been made toward defining the biochemical activities of Polycomb and trithorax group proteins, much remains to be learned about how they interact with each other and the general transcription machinery to maintain on or off states of gene expression. The trithorax group protein Kismet (KIS) is related to the SWI/SNF and CHD families of chromatin remodeling factors. KIS promotes transcription elongation, facilitates the binding of the trithorax group histone methyltransferases ASH1 and TRX to active genes, and counteracts repressive methylation of histone H3 on lysine 27 (H3K27) by Polycomb group proteins. Here, we sought to clarify the mechanism of action of KIS and how it interacts with ASH1 to antagonize H3K27 methylation in Drosophila. We present evidence that KIS promotes transcription elongation and counteracts Polycomb group repression via distinct mechanisms. A chemical inhibitor of transcription elongation, DRB, had no effect on ASH1 recruitment or H3K27 methylation. Conversely, loss of ASH1 function had no effect on transcription elongation. Mutations in kis cause a global reduction in the di- and tri-methylation of histone H3 on lysine 36 (H3K36) - modifications that antagonize H3K27 methylation in vitro. Furthermore, loss of ASH1 significantly decreases H3K36 dimethylation, providing further evidence that ASH1 is an H3K36 dimethylase in vivo. These and other findings suggest that KIS antagonizes Polycomb group repression by facilitating ASH1-dependent H3K36 dimethylation.
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Affiliation(s)
- Kristel M Dorighi
- Department of Molecular Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
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41
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Rosa-Garrido M, Karbassi E, Monte E, Vondriska TM. Regulation of chromatin structure in the cardiovascular system. Circ J 2013; 77:1389-98. [PMID: 23575346 DOI: 10.1253/circj.cj-13-0176] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
It has been appreciated for some time that cardiovascular disease involves large-scale transcriptional changes in various cell types. What has become increasingly clear only in the past few years, however, is the role of chromatin remodeling in cardiovascular phenotypes in normal physiology, as well as in development and disease. This review summarizes the state of the chromatin field in terms of distinct mechanisms to regulate chromatin structure in vivo, identifying when these modes of regulation have been demonstrated in cardiovascular tissues. We describe areas in which a better understanding of chromatin structure is leading to new insights into the fundamental biology of cardiovascular disease.
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Affiliation(s)
- Manuel Rosa-Garrido
- Department of Anesthesiology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
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The Drosophila melanogaster CHD1 chromatin remodeling factor modulates global chromosome structure and counteracts HP1a and H3K9me2. PLoS One 2013; 8:e59496. [PMID: 23533627 PMCID: PMC3606111 DOI: 10.1371/journal.pone.0059496] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 02/14/2013] [Indexed: 11/26/2022] Open
Abstract
CHD1 is a conserved chromatin remodeling factor that localizes to active genes and functions in nucleosome assembly and positioning as well as histone turnover. Mouse CHD1 is required for the maintenance of stem cell pluripotency while human CHD1 may function as a tumor suppressor. To investigate the action of CHD1 on higher order chromatin structure in differentiated cells, we examined the consequences of loss of CHD1 and over-expression of CHD1 on polytene chromosomes from salivary glands of third instar Drosophila melanogaster larvae. We observed that chromosome structure is sensitive to the amount of this remodeler. Loss of CHD1 resulted in alterations of chromosome structure and an increase in the heterochromatin protein HP1a, while over-expression of CHD1 disrupted higher order chromatin structure and caused a decrease in levels of HP1a. Over-expression of an ATPase inactive form of CHD1 did not result in severe chromosomal defects, suggesting that the ATPase activity is required for this in vivo phenotype. Interestingly, changes in CHD1 protein levels did not correlate with changes in the levels of the euchromatin mark H3K4me3 or elongating RNA Polymerase II. Thus, while CHD1 is localized to transcriptionally active regions of the genome, it can function to alter the levels of HP1a, perhaps through changes in methylation of H3K9.
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Oh H, Slattery M, Ma L, Crofts A, White KP, Mann RS, Irvine KD. Genome-wide association of Yorkie with chromatin and chromatin-remodeling complexes. Cell Rep 2013; 3:309-18. [PMID: 23395637 DOI: 10.1016/j.celrep.2013.01.008] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 10/29/2012] [Accepted: 01/11/2013] [Indexed: 12/19/2022] Open
Abstract
The Hippo pathway regulates growth through the transcriptional coactivator Yorkie, but how Yorkie promotes transcription remains poorly understood. We address this by characterizing Yorkie's association with chromatin and by identifying nuclear partners that effect transcriptional activation. Coimmunoprecipitation and mass spectrometry identify GAGA factor (GAF), the Brahma complex, and the Mediator complex as Yorkie-associated nuclear protein complexes. All three are required for Yorkie's transcriptional activation of downstream genes, and GAF and the Brahma complex subunit Moira interact directly with Yorkie. Genome-wide chromatin-binding experiments identify thousands of Yorkie sites, most of which are associated with elevated transcription, based on genome-wide analysis of messenger RNA and histone H3K4Me3 modification. Chromatin binding also supports extensive functional overlap between Yorkie and GAF. Our studies suggest a widespread role for Yorkie as a regulator of transcription and identify recruitment of the chromatin-modifying GAF protein and BRM complex as a molecular mechanism for transcriptional activation by Yorkie.
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Affiliation(s)
- Hyangyee Oh
- Howard Hughes Medical Institute, Waksman Institute, and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854, USA
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Fasulo B, Deuring R, Murawska M, Gause M, Dorighi KM, Schaaf CA, Dorsett D, Brehm A, Tamkun JW. The Drosophila MI-2 chromatin-remodeling factor regulates higher-order chromatin structure and cohesin dynamics in vivo. PLoS Genet 2012; 8:e1002878. [PMID: 22912596 PMCID: PMC3415455 DOI: 10.1371/journal.pgen.1002878] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 06/17/2012] [Indexed: 11/24/2022] Open
Abstract
dMi-2 is a highly conserved ATP-dependent chromatin-remodeling factor that regulates transcription and cell fates by altering the structure or positioning of nucleosomes. Here we report an unanticipated role for dMi-2 in the regulation of higher-order chromatin structure in Drosophila. Loss of dMi-2 function causes salivary gland polytene chromosomes to lose their characteristic banding pattern and appear more condensed than normal. Conversely, increased expression of dMi-2 triggers decondensation of polytene chromosomes accompanied by a significant increase in nuclear volume; this effect is relatively rapid and is dependent on the ATPase activity of dMi-2. Live analysis revealed that dMi-2 disrupts interactions between the aligned chromatids of salivary gland polytene chromosomes. dMi-2 and the cohesin complex are enriched at sites of active transcription; fluorescence-recovery after photobleaching (FRAP) assays showed that dMi-2 decreases stable association of cohesin with polytene chromosomes. These findings demonstrate that dMi-2 is an important regulator of both chromosome condensation and cohesin binding in interphase cells.
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Affiliation(s)
- Barbara Fasulo
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Renate Deuring
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Magdalena Murawska
- Institute for Molecular Biology and Tumor Research (IMT), Philipps-University of Marburg, Marburg, Germany
| | - Maria Gause
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Kristel M. Dorighi
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Cheri A. Schaaf
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Dale Dorsett
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Alexander Brehm
- Institute for Molecular Biology and Tumor Research (IMT), Philipps-University of Marburg, Marburg, Germany
| | - John W. Tamkun
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
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Ahmed M, Xu J, Xu PX. EYA1 and SIX1 drive the neuronal developmental program in cooperation with the SWI/SNF chromatin-remodeling complex and SOX2 in the mammalian inner ear. Development 2012; 139:1965-77. [PMID: 22513373 DOI: 10.1242/dev.071670] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Inner ear neurogenesis depends upon the function of the proneural basic helix-loop-helix (bHLH) transcription factors NEUROG1 and NEUROD1. However, the transcriptional regulation of these factors is unknown. Here, using loss- and gain-of-function models, we show that EYA1 and SIX1 are crucial otic neuronal determination factors upstream of NEUROG1 and NEUROD1. Overexpression of both Eya1 and Six1 is sufficient to convert non-neuronal epithelial cells within the otocyst and cochlea as well as the 3T3 fibroblast cells into neurons. Strikingly, all the ectopic neurons express not only Neurog1 and Neurod1 but also mature neuronal markers such as neurofilament, indicating that Eya1 and Six1 function upstream of, and in the same pathway as, Neurog1 and Neurod1 to not only induce neuronal fate but also regulate their differentiation. We demonstrate that EYA1 and SIX1 interact directly with the SWI/SNF chromatin-remodeling subunits BRG1 and BAF170 to drive neurogenesis cooperatively in 3T3 cells and cochlear nonsensory epithelial cells, and that SOX2 cooperates with these factors to mediate neuronal differentiation. Importantly, we show that the ATPase BRG1 activity is required for not only EYA1- and SIX1-induced ectopic neurogenesis but also normal neurogenesis in the otocyst. These findings indicate that EYA1 and SIX1 are key transcription factors in initiating the neuronal developmental program, probably by recruiting and interacting with the SWI/SNF chromatin-remodeling complex to specifically mediate Neurog1 and Neurod1 transcription.
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Affiliation(s)
- Mohi Ahmed
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine of NYU, New York, NY 10029, USA
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A Systematic Genetic Screen to Dissect the MicroRNA Pathway in Drosophila. G3-GENES GENOMES GENETICS 2012; 2:437-48. [PMID: 22540035 PMCID: PMC3337472 DOI: 10.1534/g3.112.002030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 01/22/2012] [Indexed: 12/19/2022]
Abstract
A central goal of microRNA biology is to elucidate the genetic program of miRNA function and regulation. However, relatively few of the effectors that execute miRNA repression have been identified. Because such genes may function in many developmental processes, mutations in them are expected to be pleiotropic and thus are discarded in most standard genetic screens. Here, we describe a systematic screen designed to identify all Drosophila genes in ∼40% of the genome that function in the miRNA pathway. To identify potentially pleiotropic genes, the screen analyzed clones of homozygous mutant cells in heterozygous animals. We identified 45 mutations representing 24 genes, and we molecularly characterized 9 genes. These include 4 previously known genes that encode core components of the miRNA pathway, including Drosha, Pasha, Dicer-1, and Ago1. The rest are new genes that function through chromatin remodeling, signaling, and mRNA decapping. The results suggest genetic screens that use clonal analysis can elucidate the miRNA program and that ∼100 genes are required to execute the miRNA program.
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Zraly CB, Dingwall AK. The chromatin remodeling and mRNA splicing functions of the Brahma (SWI/SNF) complex are mediated by the SNR1/SNF5 regulatory subunit. Nucleic Acids Res 2012; 40:5975-87. [PMID: 22467207 PMCID: PMC3401471 DOI: 10.1093/nar/gks288] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Nucleosome remodeling catalyzed by the ATP-dependent SWI/SNF complex is essential for regulated gene expression. Transcriptome profiling studies in flies and mammals identified cell cycle and hormone responsive genes as important targets of remodeling complex activities. Loss of chromatin remodeling function has been linked to developmental abnormalities and aggressive cancers. The Drosophila Brahma (Brm) SWI/SNF complex assists in reprogramming and coordinating gene expression in response to ecdysone hormone signaling at critical points during development. We used RNAi knockdown in cultured cells and transgenic flies, and conditional mutant alleles to identify unique and important functions of two conserved Brm complex core subunits, SNR1/SNF5 and BRM/SNF2-SWI2, on target gene regulation. Unexpectedly, we found that incorporation of a loss of function SNR1 subunit led to alterations in RNA polymerase elongation, pre-mRNA splicing regulation and chromatin accessibility of ecdysone hormone regulated genes, revealing that SNR1 functions to restrict BRM-dependent nucleosome remodeling activities downstream of the promoter region. Our results reveal critically important roles of the SNR1/SNF5 subunit and the Brm chromatin remodeling complex in transcription regulation during elongation by RNA Polymerase II and completion of pre-mRNA transcripts that are dependent on hormone signaling in late development.
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Affiliation(s)
- Claudia B Zraly
- Cardinal Bernardin Cancer Center, Oncology Institute, Stritch School of Medicine, Loyola University of Chicago, 2160 S. First Avenue, Maywood, IL 60153, USA
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Zhimulev IF, Belyaeva ES, Vatolina TY, Demakov SA. Banding patterns in Drosophila melanogaster polytene chromosomes correlate with DNA-binding protein occupancy. Bioessays 2012; 34:498-508. [PMID: 22419120 DOI: 10.1002/bies.201100142] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The most enigmatic feature of polytene chromosomes is their banding pattern, the genetic organization of which has been a very attractive puzzle for many years. Recent genome-wide protein mapping efforts have produced a wealth of data for the chromosome proteins of Drosophila cells. Based on their specific protein composition, the chromosomes comprise two types of bands, as well as interbands. These differ in terms of time of replication and specific types of proteins. The interbands are characterized by their association with "active" chromatin proteins, nucleosome remodeling, and origin recognition complexes, and so they have three functions: acting as binding sites for RNA pol II, initiation of replication and nucleosome remodeling of short fragments of DNA. The borders and organization of the same band and interband regions are largely identical, irrespective of the cell type studied. This demonstrates that the banding pattern is a universal principle of the organization of interphase polytene and non-polytene chromosomes.
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Affiliation(s)
- Igor F Zhimulev
- Institute of Molecular and Cellular Biology, Siberian Division of Russian Academy of Sciences, Novosibirsk, Russia.
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Aikin R, Cervantes A, D'Angelo G, Ruel L, Lacas-Gervais S, Schaub S, Thérond P. A genome-wide RNAi screen identifies regulators of cholesterol-modified hedgehog secretion in Drosophila. PLoS One 2012; 7:e33665. [PMID: 22432040 PMCID: PMC3303847 DOI: 10.1371/journal.pone.0033665] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 02/14/2012] [Indexed: 12/12/2022] Open
Abstract
Hedgehog (Hh) proteins are secreted molecules that function as organizers in animal development. In addition to being palmitoylated, Hh is the only metazoan protein known to possess a covalently-linked cholesterol moiety. The absence of either modification severely disrupts the organization of numerous tissues during development. It is currently not known how lipid-modified Hh is secreted and released from producing cells. We have performed a genome-wide RNAi screen in Drosophila melanogaster cells to identify regulators of Hh secretion. We found that cholesterol-modified Hh secretion is strongly dependent on coat protein complex I (COPI) but not COPII vesicles, suggesting that cholesterol modification alters the movement of Hh through the early secretory pathway. We provide evidence that both proteolysis and cholesterol modification are necessary for the efficient trafficking of Hh through the ER and Golgi. Finally, we identified several putative regulators of protein secretion and demonstrate a role for some of these genes in Hh and Wingless (Wg) morphogen secretion in vivo. These data open new perspectives for studying how morphogen secretion is regulated, as well as provide insight into regulation of lipid-modified protein secretion.
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Affiliation(s)
- Reid Aikin
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
| | - Alexandra Cervantes
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
| | - Gisela D'Angelo
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
| | - Laurent Ruel
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
| | - Sandra Lacas-Gervais
- Centre Commun de Microscopie Appliquée (CCMA), Université de Nice-Sophia Antipolis, Nice, France
| | - Sébastien Schaub
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
| | - Pascal Thérond
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
- * E-mail:
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50
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Soshnev AA, He B, Baxley RM, Jiang N, Hart CM, Tan K, Geyer PK. Genome-wide studies of the multi-zinc finger Drosophila Suppressor of Hairy-wing protein in the ovary. Nucleic Acids Res 2012; 40:5415-31. [PMID: 22406832 PMCID: PMC3384341 DOI: 10.1093/nar/gks225] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The Drosophila Suppressor of Hairy-wing [Su(Hw)] protein is a globally expressed, multi-zinc finger (ZnF) DNA-binding protein. Su(Hw) forms a classic insulator when bound to the gypsy retrotransposon and is essential for female germline development. These functions are genetically separable, as exemplified by Su(Hw)(f) that carries a defective ZnF10, causing a loss of insulator but not germline function. Here, we completed the first genome-wide analysis of Su(Hw)-binding sites (SBSs) in the ovary, showing that tissue-specific binding is not responsible for the restricted developmental requirements for Su(Hw). Mapping of ovary Su(Hw)(f) SBSs revealed that female fertility requires binding to only one third of the wild-type sites. We demonstrate that Su(Hw)(f) retention correlates with binding site affinity and partnership with Modifier of (mdg4) 67.2 protein. Finally, we identify clusters of co-regulated ovary genes flanked by Su(Hw)(f) bound sites and show that loss of Su(Hw) has limited effects on transcription of these genes. These data imply that the fertility function of Su(Hw) may not depend upon the demarcation of transcriptional domains. Our studies establish a framework for understanding the germline Su(Hw) function and provide insights into how chromatin occupancy is achieved by multi-ZnF proteins, the most common transcription factor class in metazoans.
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Affiliation(s)
- Alexey A Soshnev
- Interdisciplinary Program in Molecular and Cellular Biology, University of Iowa, Iowa City, IA 52242, USA
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