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Gong NN, Dilley LC, Williams CE, Moscato EH, Szuperak M, Wang Q, Jensen M, Girirajan S, Tan TY, Deardorff MA, Li D, Song Y, Kayser MS. The chromatin remodeler ISWI acts during Drosophila development to regulate adult sleep. SCIENCE ADVANCES 2021; 7:eabe2597. [PMID: 33597246 PMCID: PMC7888929 DOI: 10.1126/sciadv.abe2597] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 12/30/2020] [Indexed: 05/08/2023]
Abstract
Sleep disruptions are among the most commonly reported symptoms across neurodevelopmental disorders (NDDs), but mechanisms linking brain development to normal sleep are largely unknown. From a Drosophila screen of human NDD-associated risk genes, we identified the chromatin remodeler Imitation SWItch/SNF (ISWI) to be required for adult fly sleep. Loss of ISWI also results in disrupted circadian rhythms, memory, and social behavior, but ISWI acts in different cells and during distinct developmental times to affect each of these adult behaviors. Specifically, ISWI expression in type I neuroblasts is required for both adult sleep and formation of a learning-associated brain region. Expression in flies of the human ISWI homologs SMARCA1 and SMARCA5 differentially rescues adult phenotypes, while de novo SMARCA5 patient variants fail to rescue sleep. We propose that sleep deficits are a primary phenotype of early developmental origin in NDDs and point toward chromatin remodeling machinery as critical for sleep circuit formation.
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Affiliation(s)
- Naihua N Gong
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Leela Chakravarti Dilley
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Charlette E Williams
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Emilia H Moscato
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Milan Szuperak
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Qin Wang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Matthew Jensen
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
- Bioinformatics and Genomics Program, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Santhosh Girirajan
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
- Bioinformatics and Genomics Program, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802, USA
| | - Tiong Yang Tan
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Matthew A Deardorff
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
- Department of Pathology and Laboratory Medicine, Children's Hospital of Los Angeles, Los Angeles, CA 90027, USA
| | - Dong Li
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Yuanquan Song
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew S Kayser
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104 USA
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104 USA
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2
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Searle NE, Pillus L. Critical genomic regulation mediated by Enhancer of Polycomb. Curr Genet 2017; 64:147-154. [PMID: 28884217 DOI: 10.1007/s00294-017-0742-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 01/28/2023]
Abstract
Enhancer of Polycomb (EPC) was first identified for its contributions to development in Drosophila and was soon-thereafter purified as a subunit of the NuA4/TIP60 acetyltransferase complex. Since then, EPC has often been left in the shadows as an essential, yet non-catalytic subunit of NuA4/TIP60; however, its deep conservation and disease association make clear that it warrants additional attention. In fact, recent studies in yeast demonstrated that its Enhancer of Polycomb, Epl1, was just as important for gene expression and acetylation as is the catalytic subunit of NuA4. Despite its conservation, studies of EPC have often remained siloed between organisms. Here, our goal is to provide a cohesive view of the current state of the EPC literature as it stands among the major model organisms in which it has been studied. EPC is involved in multiple processes, beginning with its cardinal role in regulating global and targeted histone acetylation. EPC also frequently serves as an important interaction partner in these basic cellular functions, as well as in multicellular development, such as in hematopoiesis and skeletal muscle differentiation, and in human disease. Taken together, a unifying theme from these studies highlights EPC as a critical genomic regulator.
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Affiliation(s)
- Naomi E Searle
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, UC San Diego Moores Cancer Center, 9500 Gilman Drive, La Jolla, CA, 92093-0347, USA.,UC San Diego Biomedical Sciences, La Jolla, CA, 92093-0685, USA
| | - Lorraine Pillus
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, UC San Diego Moores Cancer Center, 9500 Gilman Drive, La Jolla, CA, 92093-0347, USA.
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3
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A Search for Genes Mediating the Growth-Promoting Function of TGFβ in the Drosophila melanogaster Wing Disc. Genetics 2017; 206:231-249. [PMID: 28315837 DOI: 10.1534/genetics.116.197228] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 03/09/2017] [Indexed: 12/19/2022] Open
Abstract
Transforming Growth Factor β (TGFβ) signaling has a complex influence on cell proliferation, acting to stop cell division in differentiating cells, but also promoting cell division in immature cells. The activity of the pathway in Drosophila is mostly required to stimulate the proliferation of neural and epithelial tissues. Most interestingly, this function is not absolutely required for cell division, but it is needed for these tissues to reach their correct size. It is not known how TGFβ signaling promotes cell division in imaginal discs, or what the interactions between TGFβ activity and other signaling pathways regulating cell proliferation are. In this work, we have explored the disc autonomous function of TGFβ that promotes wing imaginal disc growth. We have studied the genetic interactions between TGFβ signaling and other pathways regulating wing disc growth, such as the Insulin and Hippo/Salvador/Warts pathways, as well as cell cycle regulators. We have also identified a collection of TGFβ candidate target genes affecting imaginal growth using expression profiles. These candidates correspond to genes participating in the regulation of a variety of biochemical processes, including different aspects of cell metabolism, suggesting that TGFβ could affect cell proliferation by regulating the metabolic fitness of imaginal cells.
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4
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He S, Limi S, McGreal RS, Xie Q, Brennan LA, Kantorow WL, Kokavec J, Majumdar R, Hou H, Edelmann W, Liu W, Ashery-Padan R, Zavadil J, Kantorow M, Skoultchi AI, Stopka T, Cvekl A. Chromatin remodeling enzyme Snf2h regulates embryonic lens differentiation and denucleation. Development 2016; 143:1937-47. [PMID: 27246713 PMCID: PMC4920164 DOI: 10.1242/dev.135285] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/21/2016] [Indexed: 12/30/2022]
Abstract
Ocular lens morphogenesis is a model for investigating mechanisms of cellular differentiation, spatial and temporal gene expression control, and chromatin regulation. Brg1 (Smarca4) and Snf2h (Smarca5) are catalytic subunits of distinct ATP-dependent chromatin remodeling complexes implicated in transcriptional regulation. Previous studies have shown that Brg1 regulates both lens fiber cell differentiation and organized degradation of their nuclei (denucleation). Here, we employed a conditional Snf2h(flox) mouse model to probe the cellular and molecular mechanisms of lens formation. Depletion of Snf2h induces premature and expanded differentiation of lens precursor cells forming the lens vesicle, implicating Snf2h as a key regulator of lens vesicle polarity through spatial control of Prox1, Jag1, p27(Kip1) (Cdkn1b) and p57(Kip2) (Cdkn1c) gene expression. The abnormal Snf2h(-/-) fiber cells also retain their nuclei. RNA profiling of Snf2h(-/) (-) and Brg1(-/-) eyes revealed differences in multiple transcripts, including prominent downregulation of those encoding Hsf4 and DNase IIβ, which are implicated in the denucleation process. In summary, our data suggest that Snf2h is essential for the establishment of lens vesicle polarity, partitioning of prospective lens epithelial and fiber cell compartments, lens fiber cell differentiation, and lens fiber cell nuclear degradation.
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Grants
- R01 EY012200 NEI NIH HHS
- R01 CA079057 NCI NIH HHS
- R01 DK096266 NIDDK NIH HHS
- R01 GM116143 NIGMS NIH HHS
- R01 EY013022 NEI NIH HHS
- R01 CA076329 NCI NIH HHS
- T32 GM007491 NIGMS NIH HHS
- R56 CA079057 NCI NIH HHS
- R01 EY014237 NEI NIH HHS
- 001 World Health Organization
- R01 EY022645 NEI NIH HHS
- Grant support: R01 EY012200 (AC), EY014237 (AC), EY014237-7S1 (AC), EY013022 (MK), CA079057 (AIS), EY022645 (WL), T32 GM007491 (SL), GACR: P305/12/1033 (TS, JK), UNCE: 204021 (TS, JK), and an unrestricted grant from Research to Prevent Blindness to the Department of Ophthalmology and Visual Sciences. TS is member of the BIOCEV ? Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (CZ.1.05/1.1.00/02.0109) supported by the European Regional Development Fund. The Israel Science Foundation 610/10, the Israel Ministry of Science 36494, the Ziegler Foundation and the Binational Science Foundation (2013016) to RAP.
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Affiliation(s)
- Shuying He
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Saima Limi
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rebecca S McGreal
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Qing Xie
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Lisa A Brennan
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Wanda Lee Kantorow
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Juraj Kokavec
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA First Faculty of Medicine, Charles University, 121 08 Prague, Czech Republic
| | - Romit Majumdar
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Harry Hou
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Winfried Edelmann
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Wei Liu
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine Tel-Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Jiri Zavadil
- Department of Pathology and NYU Center for Health Informatics and Bioinformatics, New York University Langone Medical Center, New York, NY 10016, USA Mechanisms of Carcinogenesis Section, International Agency for Research on Cancer, Lyon Cedex 08 69372, France
| | - Marc Kantorow
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Tomas Stopka
- First Faculty of Medicine, Charles University, 121 08 Prague, Czech Republic
| | - Ales Cvekl
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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A genetic screen and transcript profiling reveal a shared regulatory program for Drosophila linker histone H1 and chromatin remodeler CHD1. G3-GENES GENOMES GENETICS 2015; 5:677-87. [PMID: 25628309 PMCID: PMC4390582 DOI: 10.1534/g3.115.016709] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Chromatin structure and activity can be modified through ATP-dependent repositioning of nucleosomes and posttranslational modifications of core histone tails within nucleosome core particles and by deposition of linker histones into the oligonucleosome fiber. The linker histone H1 is essential in metazoans. It has a profound effect on organization of chromatin into higher-order structures and on recruitment of histone-modifying enzymes to chromatin. Here, we describe a genetic screen for modifiers of the lethal phenotype caused by depletion of H1 in Drosophila melanogaster. We identify 41 mis-expression alleles that enhance and 20 that suppress the effect of His1 depletion in vivo. Most of them are important for chromosome organization, transcriptional regulation, and cell signaling. Specifically, the reduced viability of H1-depleted animals is strongly suppressed by ubiquitous mis-expression of the ATP-dependent chromatin remodeling enzyme CHD1. Comparison of transcript profiles in H1-depleted and Chd1 null mutant larvae revealed that H1 and CHD1 have common transcriptional regulatory programs in vivo. H1 and CHD1 share roles in repression of numerous developmentally regulated and extracellular stimulus-responsive transcripts, including immunity-related and stress response-related genes. Thus, linker histone H1 participates in various regulatory programs in chromatin to alter gene expression.
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6
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Regulation of ISWI chromatin remodelling activity. Chromosoma 2014; 123:91-102. [PMID: 24414837 DOI: 10.1007/s00412-013-0447-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 11/20/2013] [Accepted: 11/25/2013] [Indexed: 12/22/2022]
Abstract
The packaging of the eukaryotic genome into chromatin facilitates the storage of the genetic information within the nucleus, but prevents the access to the underlying DNA sequences. Structural changes in chromatin are mediated by several mechanisms. Among them, ATP-dependent remodelling complexes belonging to ISWI family provides one of the best examples that eukaryotic cells evolved to finely regulate these changes. ISWI-containing complexes use the energy derived from ATP hydrolysis to rearrange nucleosomes on chromatin in order to favour specific nuclear reactions. The combination of regulatory nuclear factors associated with the ATPase subunit as well as its modulation by specific histone modifications, specializes the nuclear function of each ISWI-containing complex. Here we review the different ways by which ISWI enzymatic activity can be modulated and regulated in the nucleus of eukaryotic cells.
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7
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Cipressa F, Cenci G. Effete, an E2 ubiquitin-conjugating enzyme with multiple roles in Drosophila development and chromatin organization. Fly (Austin) 2013; 7:256-62. [PMID: 24088712 DOI: 10.4161/fly.26567] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The Drosophila effete gene encodes an extremely conserved class I E2 ubiquitin-conjugating enzyme. Growing evidence indicates that Eff is involved in many cellular processes including eye development, maintenance of female germline stem cells, and regulation of apoptosis. Eff is also a major component of Drosophila chromatin and it is particularly enriched in chromatin with repressive properties. In addition, Eff is required for telomere protection and to prevent telomere fusion. Consistent with its multiple roles in chromatin maintenance, Eff is also one of the rare factors that modulate both telomere-induced and heterochromatin-induced position effect variegation.
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Affiliation(s)
- Francesca Cipressa
- Dipartimento di Biologia e Biotecnologie "C. Darwin"; SAPIENZA Università di Roma; Roma, Italy
| | - Giovanni Cenci
- Dipartimento di Biologia e Biotecnologie "C. Darwin"; SAPIENZA Università di Roma; Roma, Italy
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8
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Effete, a Drosophila chromatin-associated ubiquitin-conjugating enzyme that affects telomeric and heterochromatic position effect variegation. Genetics 2013; 195:147-58. [PMID: 23821599 DOI: 10.1534/genetics.113.153320] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Drosophila telomeres are elongated by the transposition of telomere-specific retrotransposons rather than telomerase activity. Proximal to the terminal transposon array, Drosophila chromosomes contain several kilobases of a complex satellite DNA termed telomere-associated sequences (TASs). Reporter genes inserted into or next to the TAS are silenced through a mechanism called telomere position effect (TPE). TPE is reminiscent of the position effect variegation (PEV) induced by Drosophila constitutive heterochromatin. However, most genes that modulate PEV have no effect on TPE, and systematic searches for TPE modifiers have so far identified only a few dominant suppressors. Surprisingly, only a few of the genes required to prevent telomere fusion have been tested for their effect on TPE. Here, we show that with the exception of the effete (eff; also called UbcD1) mutant alleles, none of the tested mutations at the other telomere fusion genes affects TPE. We also found that mutations in eff, which encodes a class I ubiquitin-conjugating enzyme, act as suppressors of PEV. Thus, eff is one of the rare genes that can modulate both TPE and PEV. Immunolocalization experiments showed that Eff is a major constituent of polytene chromosomes. Eff is enriched at several euchromatic bands and interbands, the TAS regions, and the chromocenter. Our results suggest that Eff associates with different types of chromatin affecting their abilities to regulate gene expression.
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9
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The emerging roles of ATP-dependent chromatin remodeling enzymes in nucleotide excision repair. Int J Mol Sci 2012; 13:11954-11973. [PMID: 23109894 PMCID: PMC3472786 DOI: 10.3390/ijms130911954] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 08/30/2012] [Accepted: 08/31/2012] [Indexed: 12/14/2022] Open
Abstract
DNA repair in eukaryotic cells takes place in the context of chromatin, where DNA, including damaged DNA, is tightly packed into nucleosomes and higher order chromatin structures. Chromatin intrinsically restricts accessibility of DNA repair proteins to the damaged DNA and impacts upon the overall rate of DNA repair. Chromatin is highly responsive to DNA damage and undergoes specific remodeling to facilitate DNA repair. How damaged DNA is accessed, repaired and restored to the original chromatin state, and how chromatin remodeling coordinates these processes in vivo, remains largely unknown. ATP-dependent chromatin remodelers (ACRs) are the master regulators of chromatin structure and dynamics. Conserved from yeast to humans, ACRs utilize the energy of ATP to reorganize packing of chromatin and control DNA accessibility by sliding, ejecting or restructuring nucleosomes. Several studies have demonstrated that ATP-dependent remodeling activity of ACRs plays important roles in coordination of spatio-temporal steps of different DNA repair pathways in chromatin. This review focuses on the role of ACRs in regulation of various aspects of nucleotide excision repair (NER) in the context of chromatin. We discuss current understanding of ATP-dependent chromatin remodeling by various subfamilies of remodelers and regulation of the NER pathway in vivo.
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10
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Onorati MC, Lazzaro S, Mallik M, Ingrassia AMR, Carreca AP, Singh AK, Chaturvedi DP, Lakhotia SC, Corona DFV. The ISWI chromatin remodeler organizes the hsrω ncRNA-containing omega speckle nuclear compartments. PLoS Genet 2011; 7:e1002096. [PMID: 21637796 PMCID: PMC3102753 DOI: 10.1371/journal.pgen.1002096] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 04/06/2011] [Indexed: 12/23/2022] Open
Abstract
The complexity in composition and function of the eukaryotic nucleus is achieved through its organization in specialized nuclear compartments. The Drosophila chromatin remodeling ATPase ISWI plays evolutionarily conserved roles in chromatin organization. Interestingly, ISWI genetically interacts with the hsrω gene, encoding multiple non-coding RNAs (ncRNA) essential, among other functions, for the assembly and organization of the omega speckles. The nucleoplasmic omega speckles play important functions in RNA metabolism, in normal and stressed cells, by regulating availability of hnRNPs and some other RNA processing proteins. Chromatin remodelers, as well as nuclear speckles and their associated ncRNAs, are emerging as important components of gene regulatory networks, although their functional connections have remained poorly defined. Here we provide multiple lines of evidence showing that the hsrω ncRNA interacts in vivo and in vitro with ISWI, regulating its ATPase activity. Remarkably, we found that the organization of nucleoplasmic omega speckles depends on ISWI function. Our findings highlight a novel role for chromatin remodelers in organization of nucleoplasmic compartments, providing the first example of interaction between an ATP-dependent chromatin remodeler and a large ncRNA. Chromatin structure and function are regulated by the concerted activity of covalent modifiers of chromatin, nucleosome remodeling factors, and several emerging classes of non-coding RNAs. ISWI is an evolutionarily conserved ATP-dependent chromatin remodeler playing essential roles in chromosome condensation, gene expression, and DNA replication. ISWI activity has been involved in a variety of nuclear functions including telomere silencing, stem cell renewal, neural morphogenesis, and epigenetic reprogramming. Using an in vivo assay to identify factors regulating ISWI activity in the model system Drosophila melanogaster, we recovered a genetic interaction between ISWI and hsrω. The hsrω gene encodes multiple non-coding RNAs (ncRNAs), of which the >10 kb nuclear hsrω-n RNA, with functional homolog in mammals, is essential for the assembly and organization of hnRNP-containing nucleoplasmic omega speckles. These special nuclear compartments play essential roles in the storage/sequestration of hnRNP family and other proteins, thus playing important roles in mRNA maturation and other regulatory processes. Here we show that the hsrω-n ncRNA interacts in vivo and in vitro with ISWI to directly regulate its ATPase activity. We also provide in vivo data showing that omega speckle nuclear organization depends on ISWI function, highlighting a novel role for chromatin remodelers in nuclear speckles organization.
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Affiliation(s)
- Maria C. Onorati
- Dulbecco Telethon Institute, Università degli Studi di Palermo, Dipartimento STEMBIO – Sezione Biologia Cellulare, Palermo, Italy
| | - Sandra Lazzaro
- Dulbecco Telethon Institute, Università degli Studi di Palermo, Dipartimento STEMBIO – Sezione Biologia Cellulare, Palermo, Italy
| | - Moushami Mallik
- Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, India
| | - Antonia M. R. Ingrassia
- Dulbecco Telethon Institute, Università degli Studi di Palermo, Dipartimento STEMBIO – Sezione Biologia Cellulare, Palermo, Italy
| | - Anna P. Carreca
- Dulbecco Telethon Institute, Università degli Studi di Palermo, Dipartimento STEMBIO – Sezione Biologia Cellulare, Palermo, Italy
| | - Anand K. Singh
- Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, India
| | - Deo Prakash Chaturvedi
- Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, India
| | - Subhash C. Lakhotia
- Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, India
| | - Davide F. V. Corona
- Dulbecco Telethon Institute, Università degli Studi di Palermo, Dipartimento STEMBIO – Sezione Biologia Cellulare, Palermo, Italy
- * E-mail:
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11
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Brestovitsky A, Sharf R, Mittelman K, Kleinberger T. The adenovirus E4orf4 protein targets PP2A to the ACF chromatin-remodeling factor and induces cell death through regulation of SNF2h-containing complexes. Nucleic Acids Res 2011; 39:6414-27. [PMID: 21546548 PMCID: PMC3159439 DOI: 10.1093/nar/gkr231] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The adenovirus E4 open-reading-frame 4 (E4orf4) protein regulates the progression of viral infection and when expressed individually it induces non-classical apoptosis in transformed cells. Here we show that E4orf4 associates with the ATP-dependent chromatin-remodeling factor ACF that consists of a sucrose non fermenting-2h (SNF2h) ATPase and an Acf1 regulatory subunit. Furthermore, E4orf4 targets protein phosphatase 2A (PP2A) to this complex and to chromatin. Obstruction of SNF2h activity inhibits E4orf4-induced cell death, whereas knockdown of Acf1 results in enhanced E4orf4-induced toxicity in both mammalian and yeast cells, and Acf1 overexpression inhibits E4orf4′s ability to downregulate early adenovirus gene expression in the context of viral infection. Knockdown of the Acf1 homolog, WSTF, inhibits E4orf4-induced cell death. Based on these results we suggest that the E4orf4–PP2A complex inhibits ACF and facilitates enhanced chromatin-remodeling activities of other SNF2h-containing complexes, such as WSTF–SNF2h. The resulting switch in chromatin remodeling determines life versus death decisions and contributes to E4orf4 functions during adenovirus infection.
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Affiliation(s)
- Anna Brestovitsky
- Department of Molecular Microbiology, Faculty of Medicine, Technion - Israel Institute of Technology, Bat Galim, Haifa 31096, Israel
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12
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Genome-wide characterization of chromatin binding and nucleosome spacing activity of the nucleosome remodelling ATPase ISWI. EMBO J 2011; 30:1766-77. [PMID: 21448136 DOI: 10.1038/emboj.2011.98] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Accepted: 02/25/2011] [Indexed: 12/22/2022] Open
Abstract
The evolutionarily conserved ATP-dependent nucleosome remodelling factor ISWI can space nucleosomes affecting a variety of nuclear processes. In Drosophila, loss of ISWI leads to global transcriptional defects and to dramatic alterations in higher-order chromatin structure, especially on the male X chromosome. In order to understand if chromatin condensation and gene expression defects, observed in ISWI mutants, are directly correlated with ISWI nucleosome spacing activity, we conducted a genome-wide survey of ISWI binding and nucleosome positioning in wild-type and ISWI mutant chromatin. Our analysis revealed that ISWI binds both genic and intergenic regions. Remarkably, we found that ISWI binds genes near their promoters causing specific alterations in nucleosome positioning at the level of the Transcription Start Site, providing an important insights in understanding ISWI role in higher eukaryote transcriptional regulation. Interestingly, differences in nucleosome spacing, between wild-type and ISWI mutant chromatin, tend to accumulate on the X chromosome for all ISWI-bound genes analysed. Our study shows how in higher eukaryotes the activity of the evolutionarily conserved nucleosome remodelling factor ISWI regulates gene expression and chromosome organization genome-wide.
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