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Kapur M, Molumby MJ, Guzman C, Heinz S, Ackerman SL. Cell-type-specific expression of tRNAs in the brain regulates cellular homeostasis. Neuron 2024; 112:1397-1415.e6. [PMID: 38377989 PMCID: PMC11065635 DOI: 10.1016/j.neuron.2024.01.028] [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: 07/25/2023] [Revised: 12/23/2023] [Accepted: 01/29/2024] [Indexed: 02/22/2024]
Abstract
Defects in tRNA biogenesis are associated with multiple neurological disorders, yet our understanding of these diseases has been hampered by an inability to determine tRNA expression in individual cell types within a complex tissue. Here, we developed a mouse model in which RNA polymerase III is conditionally epitope tagged in a Cre-dependent manner, allowing us to accurately profile tRNA expression in any cell type in vivo. We investigated tRNA expression in diverse nervous system cell types, revealing dramatic heterogeneity in the expression of tRNA genes between populations. We found that while maintenance of levels of tRNA isoacceptor families is critical for cellular homeostasis, neurons are differentially vulnerable to insults to distinct tRNA isoacceptor families. Cell-type-specific translatome analysis suggests that the balance between tRNA availability and codon demand may underlie such differential resilience. Our work provides a platform for investigating the complexities of mRNA translation and tRNA biology in the brain.
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Affiliation(s)
- Mridu Kapur
- Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA; The Howard Hughes Medical Institute
| | - Michael J Molumby
- Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA; The Howard Hughes Medical Institute
| | - Carlos Guzman
- Department of Medicine, Division of Endocrinology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Bioengineering, Bioinformatics & Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sven Heinz
- Department of Medicine, Division of Endocrinology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Bioengineering, Bioinformatics & Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Susan L Ackerman
- Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA; The Howard Hughes Medical Institute; Department of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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2
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Sachs P, Bergmaier P, Treutwein K, Mermoud JE. The Conserved Chromatin Remodeler SMARCAD1 Interacts with TFIIIC and Architectural Proteins in Human and Mouse. Genes (Basel) 2023; 14:1793. [PMID: 37761933 PMCID: PMC10530723 DOI: 10.3390/genes14091793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
In vertebrates, SMARCAD1 participates in transcriptional regulation, heterochromatin maintenance, DNA repair, and replication. The molecular basis underlying its involvement in these processes is not well understood. We identified the RNA polymerase III general transcription factor TFIIIC as an interaction partner of native SMARCAD1 in mouse and human models using endogenous co-immunoprecipitations. TFIIIC has dual functionality, acting as a general transcription factor and as a genome organizer separating chromatin domains. We found that its partnership with SMARCAD1 is conserved across different mammalian cell types, from somatic to pluripotent cells. Using purified proteins, we confirmed that their interaction is direct. A gene expression analysis suggested that SMARCAD1 is dispensable for TFIIIC function as an RNA polymerase III transcription factor in mouse ESCs. The distribution of TFIIIC and SMARCAD1 in the ESC genome is distinct, and unlike in yeast, SMARCAD1 is not enriched at active tRNA genes. Further analysis of SMARCAD1-binding partners in pluripotent and differentiated mammalian cells reveals that SMARCAD1 associates with several factors that have key regulatory roles in chromatin organization, such as cohesin, laminB, and DDX5. Together, our work suggests for the first time that the SMARCAD1 enzyme participates in genome organization in mammalian nuclei through interactions with architectural proteins.
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Affiliation(s)
- Parysatis Sachs
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
- CMC Development, R&D, Sanofi, 65926 Frankfurt, Germany
| | - Philipp Bergmaier
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
- Global Development Operations, R&D, Merck Healthcare, 64293 Darmstadt, Germany
| | - Katrin Treutwein
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
| | - Jacqueline E. Mermoud
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
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3
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Sizer RE, Chahid N, Butterfield SP, Donze D, Bryant NJ, White RJ. TFIIIC-based chromatin insulators through eukaryotic evolution. Gene X 2022; 835:146533. [PMID: 35623477 DOI: 10.1016/j.gene.2022.146533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 04/19/2022] [Accepted: 04/29/2022] [Indexed: 11/04/2022] Open
Abstract
Eukaryotic chromosomes are divided into domains with distinct structural and functional properties, such as differing levels of chromatin compaction and gene transcription. Domains of relatively compact chromatin and minimal transcription are termed heterochromatic, whereas euchromatin is more open and actively transcribed. Insulators separate these domains and maintain their distinct features. Disruption of insulators can cause diseases such as cancer. Many insulators contain tRNA genes (tDNAs), examples of which have been shown to block the spread of activating or silencing activities. This characteristic of specific tDNAs is conserved through evolution, such that human tDNAs can serve as barriers to the spread of silencing in fission yeast. Here we demonstrate that tDNAs from the methylotrophic fungus Pichia pastoris can function effectively as insulators in distantly-related budding yeast. Key to the function of tDNAs as insulators is TFIIIC, a transcription factor that is also required for their expression. TFIIIC binds additional loci besides tDNAs, some of which have insulator activity. Although the mechanistic basis of TFIIIC-based insulation has been studied extensively in yeast, it is largely uncharacterized in metazoa. Utilising publicly-available genome-wide ChIP-seq data, we consider the extent to which mechanisms conserved from yeast to man may suffice to allow efficient insulation by TFIIIC in the more challenging chromatin environments of metazoa and suggest features that may have been acquired during evolution to cope with new challenges. We demonstrate the widespread presence at human tDNAs of USF1, a transcription factor with well-established barrier activity in vertebrates. We predict that tDNA-based insulators in higher organisms have evolved through incorporation of modules, such as binding sites for factors like USF1 and CTCF that are absent from yeasts, thereby strengthening function and providing opportunities for regulation between cell types.
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Affiliation(s)
- Rebecca E Sizer
- Department of Biology, The University of York, York YO10 5DD, UK
| | - Nisreen Chahid
- Department of Biology, The University of York, York YO10 5DD, UK
| | | | - David Donze
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Nia J Bryant
- Department of Biology, The University of York, York YO10 5DD, UK
| | - Robert J White
- Department of Biology, The University of York, York YO10 5DD, UK.
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4
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Shao R, Kumar B, Lidschreiber K, Lidschreiber M, Cramer P, Elsässer SJ. Distinct transcription kinetics of pluripotent cell states. Mol Syst Biol 2022; 18:e10407. [PMID: 35020268 PMCID: PMC8754154 DOI: 10.15252/msb.202110407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 12/12/2021] [Accepted: 12/14/2021] [Indexed: 12/20/2022] Open
Abstract
Mouse embryonic stem cells (mESCs) can adopt naïve, ground, and paused pluripotent states that give rise to unique transcriptomes. Here, we use transient transcriptome sequencing (TT-seq) to define both coding and non-coding transcription units (TUs) in these three pluripotent states and combine TT-seq with RNA polymerase II occupancy profiling to unravel the kinetics of RNA metabolism genome-wide. Compared to the naïve state (serum), RNA synthesis and turnover rates are globally reduced in the ground state (2i) and the paused state (mTORi). The global reduction in RNA synthesis goes along with a genome-wide decrease of polymerase elongation velocity, which is related to epigenomic features and alterations in the Pol II termination window. Our data suggest that transcription activity is the main determinant of steady state mRNA levels in the naïve state and that genome-wide changes in transcription kinetics invoke ground and paused pluripotent states.
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Affiliation(s)
- Rui Shao
- Science for Life LaboratoryDepartment of Medical Biochemistry and BiophysicsDivision of Genome BiologyKarolinska InstitutetStockholmSweden
- Ming Wai Lau Centre for Reparative MedicineStockholm nodeKarolinska InstitutetStockholmSweden
| | - Banushree Kumar
- Science for Life LaboratoryDepartment of Medical Biochemistry and BiophysicsDivision of Genome BiologyKarolinska InstitutetStockholmSweden
- Ming Wai Lau Centre for Reparative MedicineStockholm nodeKarolinska InstitutetStockholmSweden
| | - Katja Lidschreiber
- Department of Biosciences and NutritionKarolinska InstitutetHuddingeSweden
- Department of Molecular BiologyMax Planck Institute for Biophysical ChemistryGöttingenGermany
| | - Michael Lidschreiber
- Department of Biosciences and NutritionKarolinska InstitutetHuddingeSweden
- Department of Molecular BiologyMax Planck Institute for Biophysical ChemistryGöttingenGermany
| | - Patrick Cramer
- Department of Biosciences and NutritionKarolinska InstitutetHuddingeSweden
- Department of Molecular BiologyMax Planck Institute for Biophysical ChemistryGöttingenGermany
| | - Simon J Elsässer
- Science for Life LaboratoryDepartment of Medical Biochemistry and BiophysicsDivision of Genome BiologyKarolinska InstitutetStockholmSweden
- Ming Wai Lau Centre for Reparative MedicineStockholm nodeKarolinska InstitutetStockholmSweden
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5
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Lata E, Choquet K, Sagliocco F, Brais B, Bernard G, Teichmann M. RNA Polymerase III Subunit Mutations in Genetic Diseases. Front Mol Biosci 2021; 8:696438. [PMID: 34395528 PMCID: PMC8362101 DOI: 10.3389/fmolb.2021.696438] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 07/21/2021] [Indexed: 12/24/2022] Open
Abstract
RNA polymerase (Pol) III transcribes small untranslated RNAs such as 5S ribosomal RNA, transfer RNAs, and U6 small nuclear RNA. Because of the functions of these RNAs, Pol III transcription is best known for its essential contribution to RNA maturation and translation. Surprisingly, it was discovered in the last decade that various inherited mutations in genes encoding nine distinct subunits of Pol III cause tissue-specific diseases rather than a general failure of all vital functions. Mutations in the POLR3A, POLR3C, POLR3E and POLR3F subunits are associated with susceptibility to varicella zoster virus-induced encephalitis and pneumonitis. In addition, an ever-increasing number of distinct mutations in the POLR3A, POLR3B, POLR1C and POLR3K subunits cause a spectrum of neurodegenerative diseases, which includes most notably hypomyelinating leukodystrophy. Furthermore, other rare diseases are also associated with mutations in genes encoding subunits of Pol III (POLR3H, POLR3GL) and the BRF1 component of the TFIIIB transcription initiation factor. Although the causal relationship between these mutations and disease development is widely accepted, the exact molecular mechanisms underlying disease pathogenesis remain enigmatic. Here, we review the current knowledge on the functional impact of specific mutations, possible Pol III-related disease-causing mechanisms, and animal models that may help to better understand the links between Pol III mutations and disease.
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Affiliation(s)
- Elisabeth Lata
- Bordeaux University, Inserm U 1212, CNRS UMR 5320, ARNA laboratory, Bordeaux, France
| | - Karine Choquet
- Department of Genetics, Harvard Medical School, Boston, MA, United States
| | - Francis Sagliocco
- Bordeaux University, Inserm U 1212, CNRS UMR 5320, ARNA laboratory, Bordeaux, France
| | - Bernard Brais
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Geneviève Bernard
- Departments of Neurology and Neurosurgery, Pediatrics and Human Genetics, McGill University, Montreal, QC, Canada
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, QC, Canada
| | - Martin Teichmann
- Bordeaux University, Inserm U 1212, CNRS UMR 5320, ARNA laboratory, Bordeaux, France
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6
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González-Jiménez A, Campos A, Navarro F, Clemente-Blanco A, Calvo O. Regulation of Eukaryotic RNAPs Activities by Phosphorylation. Front Mol Biosci 2021; 8:681865. [PMID: 34250017 PMCID: PMC8268151 DOI: 10.3389/fmolb.2021.681865] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/07/2021] [Indexed: 01/11/2023] Open
Abstract
Evolutionarily conserved kinases and phosphatases regulate RNA polymerase II (RNAPII) transcript synthesis by modifying the phosphorylation status of the carboxyl-terminal domain (CTD) of Rpb1, the largest subunit of RNAPII. Proper levels of Rpb1-CTD phosphorylation are required for RNA co-transcriptional processing and to coordinate transcription with other nuclear processes, such as chromatin remodeling and histone modification. Whether other RNAPII subunits are phosphorylated and influences their role in gene expression is still an unanswered question. Much less is known about RNAPI and RNAPIII phosphorylation, whose subunits do not contain functional CTDs. However, diverse studies have reported that several RNAPI and RNAPIII subunits are susceptible to phosphorylation. Some of these phosphorylation sites are distributed within subunits common to all three RNAPs whereas others are only shared between RNAPI and RNAPIII. This suggests that the activities of all RNAPs might be finely modulated by phosphorylation events and raises the idea of a tight coordination between the three RNAPs. Supporting this view, the transcription by all RNAPs is regulated by signaling pathways that sense different environmental cues to adapt a global RNA transcriptional response. This review focuses on how the phosphorylation of RNAPs might regulate their function and we comment on the regulation by phosphorylation of some key transcription factors in the case of RNAPI and RNAPIII. Finally, we discuss the existence of possible common mechanisms that could coordinate their activities.
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Affiliation(s)
- Araceli González-Jiménez
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Adrián Campos
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Francisco Navarro
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Jaén, Spain.,Centro de Estudios Avanzados en Aceite de Oliva y Olivar, Universidad de Jaén, Jaén, Spain
| | - Andrés Clemente-Blanco
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Olga Calvo
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
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7
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Bhargava P. Regulatory networking of the three RNA polymerases helps the eukaryotic cells cope with environmental stress. Curr Genet 2021; 67:595-603. [PMID: 33778898 DOI: 10.1007/s00294-021-01179-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 01/25/2023]
Abstract
Environmental stress influences the cellular physiology in multiple ways. Transcription by all the three RNA polymerases (Pols I, II, or III) in eukaryotes is a highly regulated process. With latest advances in technology, which have made many extensive genome-wide studies possible, it is increasingly recognized that all the cellular processes may be interconnected. A comprehensive view of the current research observations brings forward an interesting possibility that Pol II-associated factors may be directly involved in the regulation of expression from the Pol III-transcribed genes and vice versa, thus enabling a cross-talk between the two polymerases. An equally important cross-talk between the Pol I and Pol II/III has also been documented. Collectively, these observations lead to a change in the current perception that looks at the transcription of a set of genes transcribed by the three Pols in isolation. Emergence of an inclusive perspective underscores that all stress signals may converge on common mechanisms of transcription regulation, requiring an extensive cross-talk between the regulatory partners. Of the three RNA polymerases, Pol III turns out as the hub of these cross-talks, an essential component of the cellular stress-response under which the majority of the cellular transcriptional activity is shut down or re-aligned.
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Affiliation(s)
- Purnima Bhargava
- Centre for Cellular and Molecular Biology, (Council of Scientific and Industrial Research), Uppal Road, Hyderabad, 500007, India.
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8
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Functions of paralogous RNA polymerase III subunits POLR3G and POLR3GL in mouse development. Proc Natl Acad Sci U S A 2020; 117:15702-15711. [PMID: 32576691 DOI: 10.1073/pnas.1922821117] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Mammalian cells contain two isoforms of RNA polymerase III (Pol III) that differ in only a single subunit, with POLR3G in one form (Pol IIIα) and the related POLR3GL in the other form (Pol IIIβ). Previous research indicates that POLR3G and POLR3GL are differentially expressed, with POLR3G expression being highly enriched in embryonic stem cells (ESCs) and tumor cells relative to the ubiquitously expressed POLR3GL. To date, the functional differences between these two subunits remain largely unexplored, especially in vivo. Here, we show that POLR3G and POLR3GL containing Pol III complexes bind the same target genes and assume the same functions both in vitro and in vivo and, to a significant degree, can compensate for each other in vivo. Notably, an observed defect in the differentiation ability of POLR3G knockout ESCs can be rescued by exogenous expression of POLR3GL. Moreover, whereas POLR3G knockout mice die at a very early embryonic stage, POLR3GL knockout mice complete embryonic development without noticeable defects but die at about 3 wk after birth with signs of both general growth defects and potential cerebellum-related neuronal defects. The different phenotypes of the knockout mice likely reflect differential expression levels of POLR3G and POLR3GL across developmental stages and between tissues and insufficient amounts of total Pol III in vivo.
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Ferrari R, de Llobet Cucalon LI, Di Vona C, Le Dilly F, Vidal E, Lioutas A, Oliete JQ, Jochem L, Cutts E, Dieci G, Vannini A, Teichmann M, de la Luna S, Beato M. TFIIIC Binding to Alu Elements Controls Gene Expression via Chromatin Looping and Histone Acetylation. Mol Cell 2020; 77:475-487.e11. [PMID: 31759822 PMCID: PMC7014570 DOI: 10.1016/j.molcel.2019.10.020] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 08/20/2019] [Accepted: 10/13/2019] [Indexed: 12/15/2022]
Abstract
How repetitive elements, epigenetic modifications, and architectural proteins interact ensuring proper genome expression remains poorly understood. Here, we report regulatory mechanisms unveiling a central role of Alu elements (AEs) and RNA polymerase III transcription factor C (TFIIIC) in structurally and functionally modulating the genome via chromatin looping and histone acetylation. Upon serum deprivation, a subset of AEs pre-marked by the activity-dependent neuroprotector homeobox Protein (ADNP) and located near cell-cycle genes recruits TFIIIC, which alters their chromatin accessibility by direct acetylation of histone H3 lysine-18 (H3K18). This facilitates the contacts of AEs with distant CTCF sites near promoter of other cell-cycle genes, which also become hyperacetylated at H3K18. These changes ensure basal transcription of cell-cycle genes and are critical for their re-activation upon serum re-exposure. Our study reveals how direct manipulation of the epigenetic state of AEs by a general transcription factor regulates 3D genome folding and expression.
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Affiliation(s)
- Roberto Ferrari
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, Barcelona 08003, Spain.
| | - Lara Isabel de Llobet Cucalon
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, Barcelona 08003, Spain
| | - Chiara Di Vona
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, Barcelona 08003, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
| | - François Le Dilly
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, Barcelona 08003, Spain
| | - Enrique Vidal
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, Barcelona 08003, Spain
| | - Antonios Lioutas
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, Barcelona 08003, Spain
| | - Javier Quilez Oliete
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, Barcelona 08003, Spain
| | - Laura Jochem
- The Institute of Cancer Research (ICR), London, UK
| | - Erin Cutts
- The Institute of Cancer Research (ICR), London, UK
| | - Giorgio Dieci
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Alessandro Vannini
- The Institute of Cancer Research (ICR), London, UK; Human Technopole. Via Cristina Belgioioso, 171, 20157 Milano MI, Italy
| | - Martin Teichmann
- Université de Bordeaux, INSERM U1212 CNRS UMR 5320 146, Bordeaux, France
| | - Susana de la Luna
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, Barcelona 08003, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain; ICREA, Pg. Lluis Companys 23, Barcelona 08010, Spain
| | - Miguel Beato
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, Barcelona 08003, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain.
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10
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Transcription-independent TFIIIC-bound sites cluster near heterochromatin boundaries within lamina-associated domains in C. elegans. Epigenetics Chromatin 2020; 13:1. [PMID: 31918747 PMCID: PMC6950938 DOI: 10.1186/s13072-019-0325-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 12/20/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chromatin organization is central to precise control of gene expression. In various eukaryotic species, domains of pervasive cis-chromatin interactions demarcate functional domains of the genomes. In nematode Caenorhabditis elegans, however, pervasive chromatin contact domains are limited to the dosage-compensated sex chromosome, leaving the principle of C. elegans chromatin organization unclear. Transcription factor III C (TFIIIC) is a basal transcription factor complex for RNA polymerase III, and is implicated in chromatin organization. TFIIIC binding without RNA polymerase III co-occupancy, referred to as extra-TFIIIC binding, has been implicated in insulating active and inactive chromatin domains in yeasts, flies, and mammalian cells. Whether extra-TFIIIC sites are present and contribute to chromatin organization in C. elegans remains unknown. RESULTS We identified 504 TFIIIC-bound sites absent of RNA polymerase III and TATA-binding protein co-occupancy characteristic of extra-TFIIIC sites in C. elegans embryos. Extra-TFIIIC sites constituted half of all identified TFIIIC binding sites in the genome. Extra-TFIIIC sites formed dense clusters in cis. The clusters of extra-TFIIIC sites were highly over-represented within the distal arm domains of the autosomes that presented a high level of heterochromatin-associated histone H3K9 trimethylation (H3K9me3). Furthermore, extra-TFIIIC clusters were embedded in the lamina-associated domains. Despite the heterochromatin environment of extra-TFIIIC sites, the individual clusters of extra-TFIIIC sites were devoid of and resided near the individual H3K9me3-marked regions. CONCLUSION Clusters of extra-TFIIIC sites were pervasive in the arm domains of C. elegans autosomes, near the outer boundaries of H3K9me3-marked regions. Given the reported activity of extra-TFIIIC sites in heterochromatin insulation in yeasts, our observation raised the possibility that TFIIIC may also demarcate heterochromatin in C. elegans.
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11
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Clarkson CT, Deeks EA, Samarista R, Mamayusupova H, Zhurkin VB, Teif VB. CTCF-dependent chromatin boundaries formed by asymmetric nucleosome arrays with decreased linker length. Nucleic Acids Res 2019; 47:11181-11196. [PMID: 31665434 PMCID: PMC6868436 DOI: 10.1093/nar/gkz908] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/26/2019] [Accepted: 10/02/2019] [Indexed: 11/24/2022] Open
Abstract
The CCCTC-binding factor (CTCF) organises the genome in 3D through DNA loops and in 1D by setting boundaries isolating different chromatin states, but these processes are not well understood. Here we investigate chromatin boundaries in mouse embryonic stem cells, defined by the regions with decreased Nucleosome Repeat Length (NRL) for ∼20 nucleosomes near CTCF sites, affecting up to 10% of the genome. We found that the nucleosome-depleted region (NDR) near CTCF is asymmetrically located >40 nucleotides 5'-upstream from the centre of CTCF motif. The strength of CTCF binding to DNA and the presence of cohesin is correlated with the decrease of NRL near CTCF, and anti-correlated with the level of asymmetry of the nucleosome array. Individual chromatin remodellers have different contributions, with Snf2h having the strongest effect on the NRL decrease near CTCF and Chd4 playing a major role in the symmetry breaking. Upon differentiation, a subset of preserved, common CTCF sites maintains asymmetric nucleosome pattern and small NRL. The sites which lost CTCF upon differentiation are characterized by nucleosome rearrangement 3'-downstream, with unchanged NDR 5'-upstream of CTCF motifs. Boundaries of topologically associated chromatin domains frequently contain several inward-oriented CTCF motifs whose effects, described above, add up synergistically.
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Affiliation(s)
| | - Emma A Deeks
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
- Biological Sciences BSc Program, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - Ralph Samarista
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
- Wellcome Trust Vacation Student
| | - Hulkar Mamayusupova
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - Victor B Zhurkin
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Vladimir B Teif
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
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12
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Widespread Backtracking by RNA Pol II Is a Major Effector of Gene Activation, 5' Pause Release, Termination, and Transcription Elongation Rate. Mol Cell 2018; 73:107-118.e4. [PMID: 30503775 DOI: 10.1016/j.molcel.2018.10.031] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/10/2018] [Accepted: 10/17/2018] [Indexed: 10/27/2022]
Abstract
In addition to phosphodiester bond formation, RNA polymerase II has an RNA endonuclease activity, stimulated by TFIIS, which rescues complexes that have arrested and backtracked. How TFIIS affects transcription under normal conditions is poorly understood. We identified backtracking sites in human cells using a dominant-negative TFIIS (TFIISDN) that inhibits RNA cleavage and stabilizes backtracked complexes. Backtracking is most frequent within 2 kb of start sites, consistent with slow elongation early in transcription, and in 3' flanking regions where termination is enhanced by TFIISDN, suggesting that backtracked pol II is a favorable substrate for termination. Rescue from backtracking by RNA cleavage also promotes escape from 5' pause sites, prevents premature termination of long transcripts, and enhances activation of stress-inducible genes. TFIISDN slowed elongation rates genome-wide by half, suggesting that rescue of backtracked pol II by TFIIS is a major stimulus of elongation under normal conditions.
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13
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You S, Wang F, Hu Q, Li P, Zhang C, Yu Y, Zhang Y, Li Q, Bao Q, Liu P, Li J. Abnormal expression of YEATS4 associates with poor prognosis and promotes cell proliferation of hepatic carcinoma cell by regulation the TCEA1/DDX3 axis. Am J Cancer Res 2018; 8:2076-2087. [PMID: 30416857 PMCID: PMC6220140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 09/14/2018] [Indexed: 06/09/2023] Open
Abstract
YEATS domain containing 4 (YEATS4) is usually amplified and functions as an oncogene in several malignancies, such as colorectum, ovarian, breast and lung. However, the biological role of YEATS4 in hepatocellular carcinoma (HCC) has not yet been discussed. Herein, we found that YEATS4 was significantly upregulated in HCC compared to para-cancerous tissues, and was associated with poor prognosis, large tumor size, poor differentiation and distant metastasis. In addition, YEATS4 promoted HCC cell proliferation and colony formation by binding to and increasing the transcriptional activity of the TCEA1 promoter. Concurrently, upregulation of TCEA1 increased the stability of the DDX3 protein, a member of the DEAD box RNA helicase family, and augmented the proliferative and colony forming ability of HCC cells. Furthermore, YEATS4 accelerated tumor growth in vivo in a xenograft HCC model. Taken together, our study provides evidence for the first time on the potential role of the YEATS4/TCEA1/DDX3 axis in regulating HCC progression, and presents YEATS4 as a promising therapeutic target and prognosis maker for HCC.
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Affiliation(s)
- Song You
- Fujian Provincial Key Laboratory of Chronic Liver Disease and Hepatocellular Carcinoma (Xiamen University Affiliated Zhongshan Hospital)Xiamen, Fujian, China
- Graduate College of Fujian Medical UniversityFuzhou, Fujian, China
| | - Fuqiang Wang
- Department of Hepatobiliary Surgery, Zhongshan Hospital of Xiamen UniversityXiamen, Fujian, China
- Fujian Provincial Key Laboratory of Chronic Liver Disease and Hepatocellular Carcinoma (Xiamen University Affiliated Zhongshan Hospital)Xiamen, Fujian, China
| | - Qing Hu
- Medicine Clinical Laboratory of Xiamen Xianyue HospitalXiamen, Fujian, China
| | - Pengtao Li
- Department of Hepatobiliary Surgery, Zhongshan Hospital of Xiamen UniversityXiamen, Fujian, China
- Fujian Provincial Key Laboratory of Chronic Liver Disease and Hepatocellular Carcinoma (Xiamen University Affiliated Zhongshan Hospital)Xiamen, Fujian, China
| | - Changmao Zhang
- Fujian Provincial Key Laboratory of Chronic Liver Disease and Hepatocellular Carcinoma (Xiamen University Affiliated Zhongshan Hospital)Xiamen, Fujian, China
- Graduate College of Fujian Medical UniversityFuzhou, Fujian, China
| | - Yaqi Yu
- Fujian Provincial Key Laboratory of Chronic Liver Disease and Hepatocellular Carcinoma (Xiamen University Affiliated Zhongshan Hospital)Xiamen, Fujian, China
| | - Yi Zhang
- Fujian Provincial Key Laboratory of Chronic Liver Disease and Hepatocellular Carcinoma (Xiamen University Affiliated Zhongshan Hospital)Xiamen, Fujian, China
| | - Qiu Li
- Fujian Provincial Key Laboratory of Chronic Liver Disease and Hepatocellular Carcinoma (Xiamen University Affiliated Zhongshan Hospital)Xiamen, Fujian, China
| | - Qing Bao
- Fujian Provincial Key Laboratory of Chronic Liver Disease and Hepatocellular Carcinoma (Xiamen University Affiliated Zhongshan Hospital)Xiamen, Fujian, China
| | - Pingguo Liu
- Department of Hepatobiliary Surgery, Zhongshan Hospital of Xiamen UniversityXiamen, Fujian, China
- Fujian Provincial Key Laboratory of Chronic Liver Disease and Hepatocellular Carcinoma (Xiamen University Affiliated Zhongshan Hospital)Xiamen, Fujian, China
| | - Jie Li
- Department of Hepatobiliary Surgery, Zhongshan Hospital of Xiamen UniversityXiamen, Fujian, China
- Fujian Provincial Key Laboratory of Chronic Liver Disease and Hepatocellular Carcinoma (Xiamen University Affiliated Zhongshan Hospital)Xiamen, Fujian, China
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14
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Chen CY, Lanz RB, Walkey CJ, Chang WH, Lu W, Johnson DL. Maf1 and Repression of RNA Polymerase III-Mediated Transcription Drive Adipocyte Differentiation. Cell Rep 2018; 24:1852-1864. [PMID: 30110641 PMCID: PMC6138453 DOI: 10.1016/j.celrep.2018.07.046] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 04/05/2018] [Accepted: 07/12/2018] [Indexed: 12/11/2022] Open
Abstract
RNA polymerase (pol) III transcribes a variety of small untranslated RNAs involved in transcription, RNA processing, and translation. RNA pol III and its components are altered in various human developmental disorders, yet their roles in cell fate determination and development are poorly understood. Here we demonstrate that Maf1, a transcriptional repressor, promotes induction of mouse embryonic stem cells (mESCs) into mesoderm. Reduced Maf1 expression in mESCs and preadipocytes impairs adipogenesis, while ectopic Maf1 expression in Maf1-deficient cells enhances differentiation. RNA pol III repression by chemical inhibition or knockdown of Brf1 promotes adipogenesis. Altered RNA pol III-dependent transcription produces select changes in mRNAs with a significant enrichment of adipogenic gene signatures. Furthermore, RNA pol III-mediated transcription positively regulates long non-coding RNA H19 and Wnt6 expression, established adipogenesis inhibitors. Together, these studies reveal an important and unexpected function for RNA pol III-mediated transcription and Maf1 in mesoderm induction and adipocyte differentiation.
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Affiliation(s)
- Chun-Yuan Chen
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, CA, USA; Department of Molecular and Cellular Biology and the Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Rainer B Lanz
- Department of Molecular and Cellular Biology and the Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Christopher J Walkey
- Department of Molecular and Cellular Biology and the Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Wen-Hsuan Chang
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA, USA
| | - Wange Lu
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, CA, USA; Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA, USA
| | - Deborah L Johnson
- Department of Molecular and Cellular Biology and the Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA.
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15
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Ramsay EP, Vannini A. Structural rearrangements of the RNA polymerase III machinery during tRNA transcription initiation. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2018; 1861:285-294. [PMID: 29155071 DOI: 10.1016/j.bbagrm.2017.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 11/07/2017] [Accepted: 11/11/2017] [Indexed: 01/03/2023]
Abstract
RNA polymerase III catalyses the synthesis of tRNAs in eukaryotic organisms. Through combined biochemical and structural characterisation, multiple auxiliary factors have been identified alongside RNA Polymerase III as critical in both facilitating and regulating transcription. Together, this machinery forms dynamic multi-protein complexes at tRNA genes which are required for polymerase recruitment, DNA opening and initiation and elongation of the tRNA transcripts. Central to the function of these complexes is their ability to undergo multiple conformational changes and rearrangements that regulate each step. Here, we discuss the available biochemical and structural data on the structural plasticity of multi-protein complexes involved in RNA Polymerase III transcriptional initiation and facilitated re-initiation during tRNA synthesis. Increasingly, structural information is becoming available for RNA polymerase III and its functional complexes, allowing for a deeper understanding of tRNA transcriptional initiation. This article is part of a Special Issue entitled: SI: Regulation of tRNA synthesis and modification in physiological conditions and disease edited by Dr. Boguta Magdalena.
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MESH Headings
- Animals
- Eukaryotic Cells/metabolism
- Humans
- Models, Genetic
- Multiprotein Complexes/metabolism
- Promoter Regions, Genetic/genetics
- Protein Subunits
- RNA Polymerase III/chemistry
- RNA Polymerase III/metabolism
- RNA, Transfer/biosynthesis
- RNA, Transfer/genetics
- RNA, Transfer, Amino Acid-Specific/biosynthesis
- RNA, Transfer, Amino Acid-Specific/genetics
- Transcription Elongation, Genetic
- Transcription Factors/genetics
- Transcription Initiation, Genetic
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16
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Giguère V. Canonical signaling and nuclear activity of mTOR-a teamwork effort to regulate metabolism and cell growth. FEBS J 2018; 285:1572-1588. [PMID: 29337437 DOI: 10.1111/febs.14384] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 12/21/2017] [Accepted: 01/10/2018] [Indexed: 01/07/2023]
Abstract
Mechanistic (or mammalian) target of rapamycin (mTOR) is a kinase that regulates almost all functions related to cell growth and metabolism in response to extra- and intracellular stimuli, such as availability of nutrients, the presence of growth factors, or the energy status of the cell. As part of two distinct protein complexes, mTORC1 and mTORC2, the kinase has been shown to influence cell growth and proliferation by controlling ribosome biogenesis, mRNA translation, carbohydrate and lipid metabolism, protein degradation, autophagy as well as microtubule and actin dynamics. In addition to these well-characterized functions, mTOR can also influence gene transcription. While most studies focused on investigating how canonical mTOR signaling regulates the activity of transcription factors outside the nucleus, recent findings point to a more direct role for mTOR as a transcription factor operating on chromatin in the nucleus. In particular, recent genome-wide identification of mTOR targets on chromatin reveals that its activities in the nucleus and cytoplasm are functionally and biologically linked, thus uncovering a novel paradigm in mTOR function.
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Affiliation(s)
- Vincent Giguère
- Departments of Biochemistry, Medicine and Oncology, Faculty of Medicine, Goodman Cancer Research Centre, McGill University, Montréal, Canada
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17
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Abstract
Structural maintenance of chromosome (SMC) protein complexes, including cohesin and condensin, are increasingly being recognized for their important role in cancer and development, making it critical that we understand how these evolutionarily conserved multi-subunit protein complexes associate with and organize the genome. We review adaptor proteins for SMC complexes and how these adaptors may capture SMC complexes following loop extrusion to provide a framework for chromosome organization.
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Affiliation(s)
- Kobe C. Yuen
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Oncology Biomarker Development, Genentech, Inc., South San Francisco, California, United States of America
| | - Jennifer L. Gerton
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Biochemistry and Molecular Biology, University of Kansas School of Medicine, Kansas City, Kansas, United States of America
- University of Kansas Cancer Center, Kansas City, Kansas, United States of America
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18
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Büchel G, Carstensen A, Mak KY, Roeschert I, Leen E, Sumara O, Hofstetter J, Herold S, Kalb J, Baluapuri A, Poon E, Kwok C, Chesler L, Maric HM, Rickman DS, Wolf E, Bayliss R, Walz S, Eilers M. Association with Aurora-A Controls N-MYC-Dependent Promoter Escape and Pause Release of RNA Polymerase II during the Cell Cycle. Cell Rep 2017; 21:3483-3497. [PMID: 29262328 PMCID: PMC5746598 DOI: 10.1016/j.celrep.2017.11.090] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 10/12/2017] [Accepted: 11/27/2017] [Indexed: 12/17/2022] Open
Abstract
MYC proteins bind globally to active promoters and promote transcriptional elongation by RNA polymerase II (Pol II). To identify effector proteins that mediate this function, we performed mass spectrometry on N-MYC complexes in neuroblastoma cells. The analysis shows that N-MYC forms complexes with TFIIIC, TOP2A, and RAD21, a subunit of cohesin. N-MYC and TFIIIC bind to overlapping sites in thousands of Pol II promoters and intergenic regions. TFIIIC promotes association of RAD21 with N-MYC target sites and is required for N-MYC-dependent promoter escape and pause release of Pol II. Aurora-A competes with binding of TFIIIC and RAD21 to N-MYC in vitro and antagonizes association of TOP2A, TFIIIC, and RAD21 with N-MYC during S phase, blocking N-MYC-dependent release of Pol II from the promoter. Inhibition of Aurora-A in S phase restores RAD21 and TFIIIC binding to chromatin and partially restores N-MYC-dependent transcriptional elongation. We propose that complex formation with Aurora-A controls N-MYC function during the cell cycle.
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Affiliation(s)
- Gabriele Büchel
- Theodor Boveri Institute and Comprehensive Cancer Center Mainfranken, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Anne Carstensen
- Theodor Boveri Institute and Comprehensive Cancer Center Mainfranken, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ka-Yan Mak
- Theodor Boveri Institute and Comprehensive Cancer Center Mainfranken, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Isabelle Roeschert
- Theodor Boveri Institute and Comprehensive Cancer Center Mainfranken, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Eoin Leen
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK; University of Leicester, Leicester LE1 9HN, UK
| | - Olga Sumara
- Theodor Boveri Institute and Comprehensive Cancer Center Mainfranken, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Julia Hofstetter
- Cancer Systems Biology Group, Biochemistry and Molecular Biology, University of Würzburg, 97074 Würzburg, Germany
| | - Steffi Herold
- Theodor Boveri Institute and Comprehensive Cancer Center Mainfranken, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jacqueline Kalb
- Theodor Boveri Institute and Comprehensive Cancer Center Mainfranken, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Apoorva Baluapuri
- Cancer Systems Biology Group, Biochemistry and Molecular Biology, University of Würzburg, 97074 Würzburg, Germany
| | - Evon Poon
- Division of Clinical Studies and Cancer Therapeutics, The Institute of Cancer Research, The Royal Marsden NHS Trust, 15 Cotswold Rd., Belmont, Sutton, Surrey SM2 5NG, UK
| | - Colin Kwok
- Division of Clinical Studies and Cancer Therapeutics, The Institute of Cancer Research, The Royal Marsden NHS Trust, 15 Cotswold Rd., Belmont, Sutton, Surrey SM2 5NG, UK
| | - Louis Chesler
- Division of Clinical Studies and Cancer Therapeutics, The Institute of Cancer Research, The Royal Marsden NHS Trust, 15 Cotswold Rd., Belmont, Sutton, Surrey SM2 5NG, UK
| | - Hans Michael Maric
- Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - David S Rickman
- Weill Cornell Medicine, Sandra and Edward Meyer Cancer Center, 413 E. 69(th) Street, New York, NY 10021, USA
| | - Elmar Wolf
- Cancer Systems Biology Group, Biochemistry and Molecular Biology, University of Würzburg, 97074 Würzburg, Germany
| | - Richard Bayliss
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK; University of Leicester, Leicester LE1 9HN, UK
| | - Susanne Walz
- Comprehensive Cancer Center Mainfranken, Core Unit Bioinformatics, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Martin Eilers
- Theodor Boveri Institute and Comprehensive Cancer Center Mainfranken, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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19
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Karijolich J, Zhao Y, Alla R, Glaunsinger B. Genome-wide mapping of infection-induced SINE RNAs reveals a role in selective mRNA export. Nucleic Acids Res 2017; 45:6194-6208. [PMID: 28334904 PMCID: PMC5449642 DOI: 10.1093/nar/gkx180] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 03/08/2017] [Indexed: 12/11/2022] Open
Abstract
Short interspersed nuclear elements (SINEs) are retrotransposons evolutionarily derived from endogenous RNA Polymerase III RNAs. Though SINE elements have undergone exaptation into gene regulatory elements, how transcribed SINE RNA impacts transcriptional and post-transcriptional regulation is largely unknown. This is partly due to a lack of information regarding which of the loci have transcriptional potential. Here, we present an approach (short interspersed nuclear element sequencing, SINE-seq), which selectively profiles RNA Polymerase III-derived SINE RNA, thereby identifying transcriptionally active SINE loci. Applying SINE-seq to monitor murine B2 SINE expression during a gammaherpesvirus infection revealed transcription from 28 270 SINE loci, with ∼50% of active SINE elements residing within annotated RNA Polymerase II loci. Furthermore, B2 RNA can form intermolecular RNA–RNA interactions with complementary mRNAs, leading to nuclear retention of the targeted mRNA via a mechanism involving p54nrb. These findings illuminate a pathway for the selective regulation of mRNA export during stress via retrotransposon activation.
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Affiliation(s)
- John Karijolich
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720-3370, USA.,Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3370, USA.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232-2363, USA
| | - Yang Zhao
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232-2363, USA
| | - Ravi Alla
- California Institute for Quantitative Biology, University of California, Berkeley, CA 94720-3370, USA
| | - Britt Glaunsinger
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720-3370, USA.,Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3370, USA.,California Institute for Quantitative Biology, University of California, Berkeley, CA 94720-3370, USA
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20
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Park JL, Lee YS, Kunkeaw N, Kim SY, Kim IH, Lee YS. Epigenetic regulation of noncoding RNA transcription by mammalian RNA polymerase III. Epigenomics 2017; 9:171-187. [PMID: 28112569 DOI: 10.2217/epi-2016-0108] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
RNA polymerase III (Pol III) synthesizes a range of medium-sized noncoding RNAs (collectively 'Pol III genes') whose early established biological roles were so essential that they were considered 'housekeeping genes'. Besides these fundamental functions, diverse unconventional roles of mammalian Pol III genes have recently been recognized and their expression must be exquisitely controlled. In this review, we summarize the epigenetic regulation of Pol III genes by chromatin structure, histone modification and CpG DNA methylation. We also recapitulate the association between dysregulation of Pol III genes and diseases such as cancer and neurological disorders. Additionally, we will discuss why in-depth molecular studies of Pol III genes have not been attempted and how nc886, a Pol III gene, may resolve this issue.
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Affiliation(s)
- Jong-Lyul Park
- Personalized Genomic Medicine Research Center, KRIBB, Daejeon 305-806, Korea.,Department of Functional Genomics, University of Science & Technology, Daejeon 305-806, Korea
| | - Yeon-Su Lee
- Cancer Genomics Branch, Research Institute, National Cancer Center, Goyang 10408, Korea
| | - Nawapol Kunkeaw
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1072, USA.,Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Seon-Young Kim
- Personalized Genomic Medicine Research Center, KRIBB, Daejeon 305-806, Korea.,Department of Functional Genomics, University of Science & Technology, Daejeon 305-806, Korea
| | - In-Hoo Kim
- Graduate School of Cancer Science & Policy, National Cancer Center, Goyang 10408, Korea
| | - Yong Sun Lee
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1072, USA.,Graduate School of Cancer Science & Policy, National Cancer Center, Goyang 10408, Korea
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21
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Park JL, Lee YS, Song MJ, Hong SH, Ahn JH, Seo EH, Shin SP, Lee SJ, Johnson BH, Stampfer MR, Kim HP, Kim SY, Lee YS. Epigenetic regulation of RNA polymerase III transcription in early breast tumorigenesis. Oncogene 2017; 36:6793-6804. [PMID: 28846112 DOI: 10.1038/onc.2017.285] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 06/13/2017] [Accepted: 07/03/2017] [Indexed: 02/07/2023]
Abstract
RNA polymerase III (Pol III) transcribes medium-sized non-coding RNAs (collectively termed Pol III genes). Emerging diverse roles of Pol III genes suggest that individual Pol III genes are exquisitely regulated by transcription and epigenetic factors. Here we report global Pol III expression/methylation profiles and molecular mechanisms of Pol III regulation that have not been as extensively studied, using nc886 as a representative Pol III gene. In a human mammary epithelial cell system that recapitulates early breast tumorigenesis, the fraction of actively transcribed Pol III genes increases reaching a plateau during immortalization. Hyper-methylation of Pol III genes inhibits Pol III binding to DNA via inducing repressed chromatin and is a determinant for the Pol III repertoire. When Pol III genes are hypo-methylated, MYC amplifies their transcription, regardless of its recognition DNA motif. Thus, Pol III expression during tumorigenesis is delineated by methylation and magnified by MYC.
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Affiliation(s)
- J-L Park
- Personalized Genomic Medicine Research Center, KRIBB, Daejeon, Korea.,Department of Functional Genomics, University of Science and Technology, Daejeon, Korea
| | - Y-S Lee
- Rare Cancer Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - M-J Song
- Department of Environmental Medical Biology, Yonsei University College of Medicine, Seoul, Korea
| | - S-H Hong
- Rare Cancer Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - J-H Ahn
- Department of Life and Nanopharmaceutical Sciences and Department of Oriental Pharmacy, Kyung Hee University, Seoul, Korea
| | - E-H Seo
- Personalized Genomic Medicine Research Center, KRIBB, Daejeon, Korea.,Department of Functional Genomics, University of Science and Technology, Daejeon, Korea
| | - S-P Shin
- Immunotherapeutics Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - S-J Lee
- Immunotherapeutics Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - B H Johnson
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, USA
| | - M R Stampfer
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - H-P Kim
- Department of Environmental Medical Biology, Yonsei University College of Medicine, Seoul, Korea.,Institute of Tropical Medicine, Yonsei University College of Medicine, Seoul, Korea.,Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - S-Y Kim
- Personalized Genomic Medicine Research Center, KRIBB, Daejeon, Korea.,Department of Functional Genomics, University of Science and Technology, Daejeon, Korea
| | - Y S Lee
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, USA.,Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, Korea
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22
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Kim Y, Lee J, Shin H, Jang S, Kim SC, Lee Y. Biosynthesis of brain cytoplasmic 200 RNA. Sci Rep 2017; 7:6884. [PMID: 28761139 PMCID: PMC5537265 DOI: 10.1038/s41598-017-05097-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 05/10/2017] [Indexed: 12/13/2022] Open
Abstract
Brain cytoplasmic 200 RNA (BC200 RNA), a neuron-specific non-coding RNA, is also highly expressed in a number of tumors of non-neuronal origin. However, the biosynthesis of BC200 RNA remains poorly understood. In this study, we show that the efficient transcription of BC200 RNA requires both internal and upstream promoter elements in cancer cells. The transcription complex seems to interact with a broad range of sequences within the upstream 100-bp region. The cellular levels and half-lives of BC200 RNA were found to differ across various cancer cell types, but there was no significant correlation between these parameters. Exogenously expressed BC200 RNA had a shorter half-life than that observed for the endogenous version in cancer cells, suggesting that BC200 RNA might be protected by some limiting factor(s) in cancer cells. Transient transfection experiments showed that the transcriptional activity of the exogenous BC200 RNA promoter element varied depending on the cancer cell type. However, the promoter activities together with the half-life data could not explain the differences in the levels of BC200 RNA among different cell types, suggesting that there is another level of transcriptional regulation beyond that detected by our transient transfection experiments.
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Affiliation(s)
- Youngmi Kim
- Department of Chemistry, KAIST, Daejeon, 34141, Korea
| | - Jungmin Lee
- Department of Chemistry, KAIST, Daejeon, 34141, Korea
| | - Heegwon Shin
- Department of Chemistry, KAIST, Daejeon, 34141, Korea
| | - Seonghui Jang
- Department of Chemistry, KAIST, Daejeon, 34141, Korea
| | - Sun Chang Kim
- Department of Biological Sciences, KAIST, Daejeon, 34141, Korea
| | - Younghoon Lee
- Department of Chemistry, KAIST, Daejeon, 34141, Korea.
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23
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Carnevali D, Conti A, Pellegrini M, Dieci G. Whole-genome expression analysis of mammalian-wide interspersed repeat elements in human cell lines. DNA Res 2017; 24:59-69. [PMID: 28028040 PMCID: PMC5381342 DOI: 10.1093/dnares/dsw048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 10/09/2016] [Indexed: 01/06/2023] Open
Abstract
With more than 500,000 copies, mammalian-wide interspersed repeats (MIRs), a sub-group of SINEs, represent ∼2.5% of the human genome and one of the most numerous family of potential targets for the RNA polymerase (Pol) III transcription machinery. Since MIR elements ceased to amplify ∼130 myr ago, previous studies primarily focused on their genomic impact, while the issue of their expression has not been extensively addressed. We applied a dedicated bioinformatic pipeline to ENCODE RNA-Seq datasets of seven human cell lines and, for the first time, we were able to define the Pol III-driven MIR transcriptome at single-locus resolution. While the majority of Pol III-transcribed MIR elements are cell-specific, we discovered a small set of ubiquitously transcribed MIRs mapping within Pol II-transcribed genes in antisense orientation that could influence the expression of the overlapping gene. We also identified novel Pol III-transcribed ncRNAs, deriving from transcription of annotated MIR fragments flanked by unique MIR-unrelated sequences, and confirmed the role of Pol III-specific internal promoter elements in MIR transcription. Besides demonstrating widespread transcription at these retrotranspositionally inactive elements in human cells, the ability to profile MIR expression at single-locus resolution will facilitate their study in different cell types and states including pathological alterations.
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Affiliation(s)
| | - Anastasia Conti
- Department of Life Sciences, University of Parma, Parma, Italy
| | - Matteo Pellegrini
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, CA 90095 723, USA
| | - Giorgio Dieci
- Department of Life Sciences, University of Parma, Parma, Italy
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24
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Wilson KA, Wetmore SD. Combining crystallographic and quantum chemical data to understand DNA-protein π-interactions in nature. Struct Chem 2017. [DOI: 10.1007/s11224-017-0954-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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25
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Helbo AS, Lay FD, Jones PA, Liang G, Grønbæk K. Nucleosome Positioning and NDR Structure at RNA Polymerase III Promoters. Sci Rep 2017; 7:41947. [PMID: 28176797 PMCID: PMC5296907 DOI: 10.1038/srep41947] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 01/03/2017] [Indexed: 12/20/2022] Open
Abstract
Chromatin is structurally involved in the transcriptional regulation of all genes. While the nucleosome positioning at RNA polymerase II (pol II) promoters has been extensively studied, less is known about the chromatin structure at pol III promoters in human cells. We use a high-resolution analysis to show substantial differences in chromatin structure of pol II and pol III promoters, and between subtypes of pol III genes. Notably, the nucleosome depleted region at the transcription start site of pol III genes extends past the termination sequences, resulting in nucleosome free gene bodies. The +1 nucleosome is located further downstream than at pol II genes and furthermore displays weak positioning. The variable position of the +1 location is seen not only within individual cell populations and between cell types, but also between different pol III promoter subtypes, suggesting that the +1 nucleosome may be involved in the transcriptional regulation of pol III genes. We find that expression and DNA methylation patterns correlate with distinct accessibility patterns, where DNA methylation associates with the silencing and inaccessibility at promoters. Taken together, this study provides the first high-resolution map of nucleosome positioning and occupancy at human pol III promoters at specific loci and genome wide.
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Affiliation(s)
- Alexandra Søgaard Helbo
- Department of Hematology, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Fides D Lay
- Department of Urology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, 90089, USA
| | - Peter A Jones
- Department of Urology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, 90089, USA.,Van Andel Research Institute, Grand Rapids, 49503, USA
| | - Gangning Liang
- Department of Urology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, 90089, USA
| | - Kirsten Grønbæk
- Department of Hematology, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, 2100, Denmark
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26
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Abstract
Recent years have seen a burst in the number of studies investigating tRNA biology. With the transition from a gene-centred to a genome-centred perspective, tRNAs and other RNA polymerase III transcripts surfaced as active regulators of normal cell physiology and disease. Novel strategies removing some of the hurdles that prevent quantitative tRNA profiling revealed that the differential exploitation of the tRNA pool critically affects the ability of the cell to balance protein homeostasis during normal and stress conditions. Furthermore, growing evidence indicates that the adaptation of tRNA synthesis to cellular dynamics can influence translation and mRNA stability to drive carcinogenesis and other pathological disorders. This review explores the contribution given by genomics, transcriptomics and epitranscriptomics to the discovery of emerging tRNA functions, and gives insights into some of the technical challenges that still limit our understanding of the RNA polymerase III transcriptional machinery.
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Affiliation(s)
- Andrea Orioli
- Center for Integrative Genomics, Université de Lausanne, Lausanne, VD 1015, Switzerland
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27
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Rudolph KLM, Schmitt BM, Villar D, White RJ, Marioni JC, Kutter C, Odom DT. Codon-Driven Translational Efficiency Is Stable across Diverse Mammalian Cell States. PLoS Genet 2016; 12:e1006024. [PMID: 27166679 PMCID: PMC4864286 DOI: 10.1371/journal.pgen.1006024] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 04/12/2016] [Indexed: 11/19/2022] Open
Abstract
Whether codon usage fine-tunes mRNA translation in mammals remains controversial, with recent papers suggesting that production of proteins in specific Gene Ontological (GO) pathways can be regulated by actively modifying the codon and anticodon pools in different cellular conditions. In this work, we compared the sequence content of genes in specific GO categories with the exonic genome background. Although a substantial fraction of variability in codon usage could be explained by random sampling, almost half of GO sets showed more variability in codon usage than expected by chance. Nevertheless, by quantifying translational efficiency in healthy and cancerous tissues in human and mouse, we demonstrated that a given tRNA pool can equally well translate many different sets of mRNAs, irrespective of their cell-type specificity. This disconnect between variations in codon usage and the stability of translational efficiency is best explained by differences in GC content between gene sets. GC variation across the mammalian genome is most likely a result of the interplay between genome repair and gene duplication mechanisms, rather than selective pressures caused by codon-driven translational rates. Consequently, codon usage differences in mammalian transcriptomes are most easily explained by well-understood mutational biases acting on the underlying genome.
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Affiliation(s)
- Konrad L. M. Rudolph
- European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge, United Kingdom
| | - Bianca M. Schmitt
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, United Kingdom
| | - Diego Villar
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, United Kingdom
| | - Robert J. White
- University of York, Department of Biology, York, United Kingdom
| | - John C. Marioni
- European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge, United Kingdom
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, United Kingdom
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Claudia Kutter
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, United Kingdom
- Science for Life Laboratory, Karolinska Institute, Department of Microbiology, Tumor and Cell Biology, Stockholm, Sweden
| | - Duncan T. Odom
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, United Kingdom
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
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28
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Gouge J, Satia K, Guthertz N, Widya M, Thompson AJ, Cousin P, Dergai O, Hernandez N, Vannini A. Redox Signaling by the RNA Polymerase III TFIIB-Related Factor Brf2. Cell 2016; 163:1375-87. [PMID: 26638071 PMCID: PMC4671959 DOI: 10.1016/j.cell.2015.11.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 10/14/2015] [Accepted: 10/23/2015] [Indexed: 01/06/2023]
Abstract
TFIIB-related factor 2 (Brf2) is a member of the family of TFIIB-like core transcription factors. Brf2 recruits RNA polymerase (Pol) III to type III gene-external promoters, including the U6 spliceosomal RNA and selenocysteine tRNA genes. Found only in vertebrates, Brf2 has been linked to tumorigenesis but the underlying mechanisms remain elusive. We have solved crystal structures of a human Brf2-TBP complex bound to natural promoters, obtaining a detailed view of the molecular interactions occurring at Brf2-dependent Pol III promoters and highlighting the general structural and functional conservation of human Pol II and Pol III pre-initiation complexes. Surprisingly, our structural and functional studies unravel a Brf2 redox-sensing module capable of specifically regulating Pol III transcriptional output in living cells. Furthermore, we establish Brf2 as a central redox-sensing transcription factor involved in the oxidative stress pathway and provide a mechanistic model for Brf2 genetic activation in lung and breast cancer. Architectural conservation of TFIIB and TFIIB-related factors Brf2 is a redox-sensing RNA polymerase III core transcription factor Brf2 regulates cellular responses to oxidative stress Brf2 amplification enables cancer cells to evade oxidative stress-induced apoptosis
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Affiliation(s)
- Jerome Gouge
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Karishma Satia
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Nicolas Guthertz
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Marcella Widya
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Andrew James Thompson
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Pascal Cousin
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Oleksandr Dergai
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Nouria Hernandez
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Alessandro Vannini
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK.
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Pugh BF, Venters BJ. Genomic Organization of Human Transcription Initiation Complexes. PLoS One 2016; 11:e0149339. [PMID: 26866362 PMCID: PMC4750860 DOI: 10.1371/journal.pone.0149339] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 01/29/2016] [Indexed: 11/29/2022] Open
Abstract
A repertoire of transcription initiation factors engage the core promoter of mRNA genes to recruit RNA polymerase (Pol) II to initiate transcription, yet their precise spatial organization remains unclear. Using ChIP-exo, here we detail the interactions and genomic organization of initiation factors TBP, TFIIB, and Pol II at mRNA genes and within CpG islands. We find that when Pol II moves into a transcriptionally paused state, TBP/TFIIB remain at the promoter. We show that TBP and TFIIB bound to the core promoter at two separate, resolvable locations that coincided with sites of divergent transcription initiation. We also examine the precise binding of TBP at Pol III transcribed tRNA genes. We find that TBP crosslinked to tRNA genes in a similar manner as at Pol II transcribed genes. This comprehensive and high resolution genome-wide detection of the initiation machinery produces a consolidated view of transcription initiation events humans at Pol II coding and Pol III transcribed tRNA genes.
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Affiliation(s)
- B. Franklin Pugh
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Bryan J. Venters
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
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30
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Genome-wide nucleosome specificity and function of chromatin remodellers in ES cells. Nature 2016; 530:113-6. [PMID: 26814966 PMCID: PMC4871117 DOI: 10.1038/nature16505] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 12/01/2015] [Indexed: 12/15/2022]
Abstract
ATP-dependent chromatin remodellers allow access to DNA for transcription factors and the general transcription machinery, but whether mammalian chromatin remodellers target specific nucleosomes to regulate transcription is unclear. Here we present genome-wide remodeller-nucleosome interaction profiles for the chromatin remodellers Chd1, Chd2, Chd4, Chd6, Chd8, Chd9, Brg1 and Ep400 in mouse embryonic stem (ES) cells. These remodellers bind one or both full nucleosomes that flank micrococcal nuclease (MNase)-defined nucleosome-free promoter regions (NFRs), where they separate divergent transcription. Surprisingly, large CpG-rich NFRs that extend downstream of annotated transcriptional start sites are nevertheless bound by non-nucleosomal or subnucleosomal histone variants (H3.3 and H2A.Z) and marked by H3K4me3 and H3K27ac modifications. RNA polymerase II therefore navigates hundreds of base pairs of altered chromatin in the sense direction before encountering an MNase-resistant nucleosome at the 3' end of the NFR. Transcriptome analysis after remodeller depletion reveals reciprocal mechanisms of transcriptional regulation by remodellers. Whereas at active genes individual remodellers have either positive or negative roles via altering nucleosome stability, at polycomb-enriched bivalent genes the same remodellers act in an opposite manner. These findings indicate that remodellers target specific nucleosomes at the edge of NFRs, where they regulate ES cell transcriptional programs.
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31
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Xu C, Corces VG. Towards a predictive model of chromatin 3D organization. Semin Cell Dev Biol 2015; 57:24-30. [PMID: 26658098 DOI: 10.1016/j.semcdb.2015.11.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 11/24/2015] [Accepted: 11/26/2015] [Indexed: 01/19/2023]
Abstract
Architectural proteins mediate interactions between distant regions in the genome to bring together different regulatory elements while establishing a specific three-dimensional organization of the genetic material. Depletion of specific architectural proteins leads to miss regulation of gene expression and alterations in nuclear organization. The specificity of interactions mediated by architectural proteins depends on the nature, number, and orientation of their binding site at individual genomic locations. Knowledge of the mechanisms and rules governing interactions among architectural proteins may provide a code to predict the 3D organization of the genome.
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Affiliation(s)
- Chenhuan Xu
- Department of Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Victor G Corces
- Department of Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA.
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32
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Zakari M, Yuen K, Gerton JL. Etiology and pathogenesis of the cohesinopathies. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2015; 4:489-504. [PMID: 25847322 PMCID: PMC6680315 DOI: 10.1002/wdev.190] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 03/02/2015] [Accepted: 03/03/2015] [Indexed: 01/12/2023]
Abstract
Cohesin is a chromosome-associated protein complex that plays many important roles in chromosome function. Genetic screens in yeast originally identified cohesin as a key regulator of chromosome segregation. Subsequently, work by various groups has identified cohesin as critical for additional processes such as DNA damage repair, insulator function, gene regulation, and chromosome condensation. Mutations in the genes encoding cohesin and its accessory factors result in a group of developmental and intellectual impairment diseases termed 'cohesinopathies.' How mutations in cohesin genes cause disease is not well understood as precocious chromosome segregation is not a common feature in cells derived from patients with these syndromes. In this review, the latest findings concerning cohesin's function in the organization of chromosome structure and gene regulation are discussed. We propose that the cohesinopathies are caused by changes in gene expression that can negatively impact translation. The similarities and differences between cohesinopathies and ribosomopathies, diseases caused by defects in ribosome biogenesis, are discussed. The contribution of cohesin and its accessory proteins to gene expression programs that support translation suggests that cohesin provides a means of coupling chromosome structure with the translational output of cells.
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Affiliation(s)
- Musinu Zakari
- Stowers Institute for Medical Research, Kansas City, MO, USA
- Universite Pierre et Marie Curie, Paris, France
| | - Kobe Yuen
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Jennifer L Gerton
- Stowers Institute for Medical Research, Kansas City, MO, USA
- Department of Biochemistry and Molecular Biology, University of Kansas School of Medicine, Kansas City, KS, USA
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33
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Maliszewska-Olejniczak K, Gruchota J, Gromadka R, Denby Wilkes C, Arnaiz O, Mathy N, Duharcourt S, Bétermier M, Nowak JK. TFIIS-Dependent Non-coding Transcription Regulates Developmental Genome Rearrangements. PLoS Genet 2015; 11:e1005383. [PMID: 26177014 PMCID: PMC4503560 DOI: 10.1371/journal.pgen.1005383] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 06/22/2015] [Indexed: 02/07/2023] Open
Abstract
Because of their nuclear dimorphism, ciliates provide a unique opportunity to study the role of non-coding RNAs (ncRNAs) in the communication between germline and somatic lineages. In these unicellular eukaryotes, a new somatic nucleus develops at each sexual cycle from a copy of the zygotic (germline) nucleus, while the old somatic nucleus degenerates. In the ciliate Paramecium tetraurelia, the genome is massively rearranged during this process through the reproducible elimination of repeated sequences and the precise excision of over 45,000 short, single-copy Internal Eliminated Sequences (IESs). Different types of ncRNAs resulting from genome-wide transcription were shown to be involved in the epigenetic regulation of genome rearrangements. To understand how ncRNAs are produced from the entire genome, we have focused on a homolog of the TFIIS elongation factor, which regulates RNA polymerase II transcriptional pausing. Six TFIIS-paralogs, representing four distinct families, can be found in P. tetraurelia genome. Using RNA interference, we showed that TFIIS4, which encodes a development-specific TFIIS protein, is essential for the formation of a functional somatic genome. Molecular analyses and high-throughput DNA sequencing upon TFIIS4 RNAi demonstrated that TFIIS4 is involved in all kinds of genome rearrangements, including excision of ~48% of IESs. Localization of a GFP-TFIIS4 fusion revealed that TFIIS4 appears specifically in the new somatic nucleus at an early developmental stage, before IES excision. RT-PCR experiments showed that TFIIS4 is necessary for the synthesis of IES-containing non-coding transcripts. We propose that these IES+ transcripts originate from the developing somatic nucleus and serve as pairing substrates for germline-specific short RNAs that target elimination of their homologous sequences. Our study, therefore, connects the onset of zygotic non coding transcription to the control of genome plasticity in Paramecium, and establishes for the first time a specific role of TFIIS in non-coding transcription in eukaryotes. Paramecium tetraurelia provides an excellent model for studying the mechanisms involved in the production of non-coding transcripts and their mode of action. Different types of non-coding RNAs (ncRNAs) were shown to be implicated in the programmed DNA elimination process that occurs in this organism. At each sexual cycle, during development of the somatic nucleus from the germline nucleus, the genome is massively rearranged through the reproducible elimination of germline-specific sequences including thousands of short, single copy, non-coding Internal Eliminated Sequences (IES). Here, we demonstrate, using RNA interference, that the TFIIS4 gene encoding a development-specific homolog of RNA polymerase II elongation factor TFIIS, is indispensable for ncRNA synthesis in the new somatic nucleus. TFIIS4 depletion impairs the assembly of a functional somatic genome and affects excision of a large fraction of IESs, which leads to strong lethality in the sexual progeny. We propose that TFIIS4-dependent ncRNAs provide an important component of the molecular machinery that is responsible for developmental genome remodeling in Paramecium.
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Affiliation(s)
| | - Julita Gruchota
- Institute of Biochemistry and Biophysics, PAS, Warsaw, Poland
| | - Robert Gromadka
- Institute of Biochemistry and Biophysics, PAS, Warsaw, Poland
| | - Cyril Denby Wilkes
- Institute for Integrative Biology of the Cell (I2BC), CNRS, CEA, Université Paris Sud, Gif-sur-Yvette, France
| | - Olivier Arnaiz
- Institute for Integrative Biology of the Cell (I2BC), CNRS, CEA, Université Paris Sud, Gif-sur-Yvette, France
| | - Nathalie Mathy
- Institute for Integrative Biology of the Cell (I2BC), CNRS, CEA, Université Paris Sud, Gif-sur-Yvette, France
| | - Sandra Duharcourt
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Mireille Bétermier
- Institute for Integrative Biology of the Cell (I2BC), CNRS, CEA, Université Paris Sud, Gif-sur-Yvette, France
| | - Jacek K. Nowak
- Institute of Biochemistry and Biophysics, PAS, Warsaw, Poland
- * E-mail:
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34
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Lee YL, Li YC, Su CH, Chiao CH, Lin IH, Hsu MT. MAF1 represses CDKN1A through a Pol III-dependent mechanism. eLife 2015; 4:e06283. [PMID: 26067234 PMCID: PMC4480132 DOI: 10.7554/elife.06283] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 06/09/2015] [Indexed: 11/24/2022] Open
Abstract
MAF1 represses Pol III-mediated transcription by interfering with TFIIIB and Pol III. Herein, we found that MAF1 knockdown induced CDKN1A transcription and chromatin looping concurrently with Pol III recruitment. Simultaneous knockdown of MAF1 with Pol III or BRF1 (subunit of TFIIIB) diminished the activation and looping effect, which indicates that recruiting Pol III was required for activation of Pol II-mediated transcription and chromatin looping. Chromatin-immunoprecipitation analysis after MAF1 knockdown indicated enhanced binding of Pol III and BRF1, as well as of CFP1, p300, and PCAF, which are factors that mediate active histone marks, along with the binding of TATA binding protein (TBP) and POLR2E to the CDKN1A promoter. Simultaneous knockdown with Pol III abolished these regulatory events. Similar results were obtained for GDF15. Our results reveal a novel mechanism by which MAF1 and Pol III regulate the activity of a protein-coding gene transcribed by Pol II. DOI:http://dx.doi.org/10.7554/eLife.06283.001 An organism's genetic material is made of segments of DNA called genes, which contain instructions to make proteins. First, copies of the DNA are made using another molecule called ribonucleic acid (RNA) in a process known as transcription. Then the RNA is used as a template to make a protein. During transcription, enzymes called RNA polymerases move along the DNA to produce the RNA copies. When a cell is actively growing it needs large quantities of new proteins to be made, and so the level of transcription is higher. However, if a cell experiences stress caused by adverse environmental conditions (e.g., high temperatures), it can conserve resources by shutting down transcription. For example, one RNA polymerase—called Pol III—makes RNA copies with the help of a protein called BRF1 and several other proteins. However, when a cell is under stress, another protein called MAF1 can interfere with transcription by binding to BRF1, which prevents it from interacting with Pol III. Previous work has suggested that MAF1 can also inhibit the activity of another RNA polymerase called Pol II, but it was not clear how this could work. Lee et al. studied the effect of MAF1 on transcription in human cells. The experiments show that MAF1 blocks the transcription of many genes that are transcribed by Pol II, including one called CDKN1A. CDKN1A is involved in regulating many important processes, including the growth of cells and cell death. Cells that produced lower amounts of MAF1 had higher levels of CDKN1A transcription, and several proteins—including Pol II, Pol III and BRF1—were more able to bind to this gene. However, this effect was not observed in cells that also produced lower levels of Pol III or BRF1, suggesting that Pol III is needed for Pol II to be able to transcribe CDKN1A. Taken together, Lee et al.'s findings suggest that MAF1 inhibits the transcription of CDKN1A, and possibly other genes transcribed by Pol II, by regulating the activity of Pol III. Further research is needed to understand the details of how this works. DOI:http://dx.doi.org/10.7554/eLife.06283.002
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Affiliation(s)
- Yu-Ling Lee
- Institute of Biochemistry and Molecular Biology, School of Life Science, National Yang-Ming University, Taipei, Taiwan
| | - Yuan-Ching Li
- Institute of Biochemistry and Molecular Biology, School of Life Science, National Yang-Ming University, Taipei, Taiwan
| | - Chia-Hsin Su
- Institute of Biochemistry and Molecular Biology, School of Life Science, National Yang-Ming University, Taipei, Taiwan
| | - Chun-Hui Chiao
- Institute of Biochemistry and Molecular Biology, School of Life Science, National Yang-Ming University, Taipei, Taiwan
| | - I-Hsuan Lin
- Institute of Biochemistry and Molecular Biology, School of Life Science, National Yang-Ming University, Taipei, Taiwan
| | - Ming-Ta Hsu
- Institute of Biochemistry and Molecular Biology, School of Life Science, National Yang-Ming University, Taipei, Taiwan
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35
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Schmitt BM, Rudolph KLM, Karagianni P, Fonseca NA, White RJ, Talianidis I, Odom DT, Marioni JC, Kutter C. High-resolution mapping of transcriptional dynamics across tissue development reveals a stable mRNA-tRNA interface. Genome Res 2014; 24:1797-807. [PMID: 25122613 PMCID: PMC4216921 DOI: 10.1101/gr.176784.114] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The genetic code is an abstraction of how mRNA codons and tRNA anticodons molecularly interact during protein synthesis; the stability and regulation of this interaction remains largely unexplored. Here, we characterized the expression of mRNA and tRNA genes quantitatively at multiple time points in two developing mouse tissues. We discovered that mRNA codon pools are highly stable over development and simply reflect the genomic background; in contrast, precise regulation of tRNA gene families is required to create the corresponding tRNA transcriptomes. The dynamic regulation of tRNA genes during development is controlled in order to generate an anticodon pool that closely corresponds to messenger RNAs. Thus, across development, the pools of mRNA codons and tRNA anticodons are invariant and highly correlated, revealing a stable molecular interaction interlocking transcription and translation.
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Affiliation(s)
- Bianca M Schmitt
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, CB2 0RE, United Kingdom
| | - Konrad L M Rudolph
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | | | - Nuno A Fonseca
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | - Robert J White
- University of York, Department of Biology, Heslington, York, YO10 5DD, United Kingdom
| | | | - Duncan T Odom
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, CB2 0RE, United Kingdom;
| | - John C Marioni
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom;
| | - Claudia Kutter
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, CB2 0RE, United Kingdom;
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36
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Pinskaya M, Ghavi-Helm Y, Mariotte-Labarre S, Morillon A, Soutourina J, Werner M. PHD and TFIIS-Like domains of the Bye1 transcription factor determine its multivalent genomic distribution. PLoS One 2014; 9:e102464. [PMID: 25029256 PMCID: PMC4100922 DOI: 10.1371/journal.pone.0102464] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 06/19/2014] [Indexed: 11/18/2022] Open
Abstract
The BYpass of Ess1 (Bye1) protein is a putative S. cerevisiae transcription factor homologous to the human cancer-associated PHF3/DIDO family of proteins. Bye1 contains a Plant Homeodomain (PHD) and a TFIIS-like domain. The Bye1 PHD finger interacts with tri-methylated lysine 4 of histone H3 (H3K4me3) while the TFIIS-like domain binds to RNA polymerase (Pol) II. Here, we investigated the contribution of these structural features to Bye1 recruitment to chromatin as well as its function in transcriptional regulation. Genome-wide analysis of Bye1 distribution revealed at least two distinct modes of association with actively transcribed genes: within the core of Pol II- and Pol III-transcribed genes concomitant with the presence of the TFIIS transcription factor and, additionally, with promoters of a subset of Pol II-transcribed genes. Specific loss of H3K4me3 abolishes Bye1 association to gene promoters, but doesn't affect its binding within gene bodies. Genetic interactions suggested an essential role of Bye1 in cell fitness under stress conditions compensating the absence of TFIIS. Furthermore, BYE1 deletion resulted in the attenuation of GAL genes expression upon galactose-mediated induction indicating its positive role in transcription regulation. Together, these findings point to a bimodal role of Bye1 in regulation of Pol II transcription. It is recruited via its PHD domain to H3K4 tri-methylated promoters at early steps of transcription. Once Pol II is engaged into elongation, Bye1 binds directly to the transcriptional machinery, modulating its progression along the gene.
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Affiliation(s)
- Marina Pinskaya
- iBiTec-S CEA, FRE3377, Gif-sur-Yvette, France
- CNRS, FRE3377, Gif-sur-Yvette, France
- Université Paris-Sud, FRE3377, Gif-sur-Yvette, France
- ncRNA, epigenetic and genome fluidity, Institut Curie, Centre de Recherche, CNRS UMR3244, Université Pierre et Marie Curie, Paris, France
- * E-mail: (MW); (MP)
| | - Yad Ghavi-Helm
- iBiTec-S CEA, FRE3377, Gif-sur-Yvette, France
- CNRS, FRE3377, Gif-sur-Yvette, France
- Université Paris-Sud, FRE3377, Gif-sur-Yvette, France
| | - Sylvie Mariotte-Labarre
- iBiTec-S CEA, FRE3377, Gif-sur-Yvette, France
- CNRS, FRE3377, Gif-sur-Yvette, France
- Université Paris-Sud, FRE3377, Gif-sur-Yvette, France
| | - Antonin Morillon
- ncRNA, epigenetic and genome fluidity, Institut Curie, Centre de Recherche, CNRS UMR3244, Université Pierre et Marie Curie, Paris, France
| | - Julie Soutourina
- iBiTec-S CEA, FRE3377, Gif-sur-Yvette, France
- CNRS, FRE3377, Gif-sur-Yvette, France
- Université Paris-Sud, FRE3377, Gif-sur-Yvette, France
| | - Michel Werner
- iBiTec-S CEA, FRE3377, Gif-sur-Yvette, France
- CNRS, FRE3377, Gif-sur-Yvette, France
- Université Paris-Sud, FRE3377, Gif-sur-Yvette, France
- * E-mail: (MW); (MP)
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Van Bortle K, Nichols MH, Li L, Ong CT, Takenaka N, Qin ZS, Corces VG. Insulator function and topological domain border strength scale with architectural protein occupancy. Genome Biol 2014; 15:R82. [PMID: 24981874 PMCID: PMC4226948 DOI: 10.1186/gb-2014-15-5-r82] [Citation(s) in RCA: 208] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 06/30/2014] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Chromosome conformation capture studies suggest that eukaryotic genomes are organized into structures called topologically associating domains. The borders of these domains are highly enriched for architectural proteins with characterized roles in insulator function. However, a majority of architectural protein binding sites localize within topological domains, suggesting sites associated with domain borders represent a functionally different subclass of these regulatory elements. How topologically associating domains are established and what differentiates border-associated from non-border architectural protein binding sites remain unanswered questions. RESULTS By mapping the genome-wide target sites for several Drosophila architectural proteins, including previously uncharacterized profiles for TFIIIC and SMC-containing condensin complexes, we uncover an extensive pattern of colocalization in which architectural proteins establish dense clusters at the borders of topological domains. Reporter-based enhancer-blocking insulator activity as well as endogenous domain border strength scale with the occupancy level of architectural protein binding sites, suggesting co-binding by architectural proteins underlies the functional potential of these loci. Analyses in mouse and human stem cells suggest that clustering of architectural proteins is a general feature of genome organization, and conserved architectural protein binding sites may underlie the tissue-invariant nature of topologically associating domains observed in mammals. CONCLUSIONS We identify a spectrum of architectural protein occupancy that scales with the topological structure of chromosomes and the regulatory potential of these elements. Whereas high occupancy architectural protein binding sites associate with robust partitioning of topologically associating domains and robust insulator function, low occupancy sites appear reserved for gene-specific regulation within topological domains.
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Affiliation(s)
- Kevin Van Bortle
- Department of Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Michael H Nichols
- Department of Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Li Li
- Department of Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, GA 30322, USA
| | - Chin-Tong Ong
- Department of Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Naomi Takenaka
- Department of Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Zhaohui S Qin
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, GA 30322, USA
| | - Victor G Corces
- Department of Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA
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Sheikh BN. Crafting the brain - role of histone acetyltransferases in neural development and disease. Cell Tissue Res 2014; 356:553-73. [PMID: 24788822 DOI: 10.1007/s00441-014-1835-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/30/2014] [Indexed: 01/19/2023]
Abstract
The human brain is a highly specialized organ containing nearly 170 billion cells with specific functions. Development of the brain requires adequate proliferation, proper cell migration, differentiation and maturation of progenitors. This is in turn dependent on spatial and temporal coordination of gene transcription, which requires the integration of both cell intrinsic and environmental factors. Histone acetyltransferases (HATs) are one family of proteins that modulate expression levels of genes in a space- and time-dependent manner. HATs and their molecular complexes are able to integrate multiple molecular inputs and mediate transcriptional levels by acetylating histone proteins. In mammals, 19 HATs have been described and are separated into five families (p300/CBP, MYST, GNAT, NCOA and transcription-related HATs). During embryogenesis, individual HATs are expressed or activated at specific times and locations to coordinate proper development. Not surprisingly, mutations in HATs lead to severe developmental abnormalities in the nervous system and increased neurodegeneration. This review focuses on our current understanding of HATs and their biological roles during neural development.
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Affiliation(s)
- Bilal N Sheikh
- Division of Development and Cancer, The Walter and Eliza Hall Institute of Medical Research, Melbourne, 3052, Victoria, Australia,
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39
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Ong CT, Corces VG. CTCF: an architectural protein bridging genome topology and function. Nat Rev Genet 2014; 15:234-46. [PMID: 24614316 DOI: 10.1038/nrg3663] [Citation(s) in RCA: 703] [Impact Index Per Article: 70.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The eukaryotic genome is organized in the three-dimensional nuclear space in a specific manner that is both a cause and a consequence of its function. This organization is partly established by a special class of architectural proteins, of which CCCTC-binding factor (CTCF) is the best characterized. Although CTCF has been assigned various roles that are often contradictory, new results now help to draw a unifying model to explain the many functions of this protein. CTCF creates boundaries between topologically associating domains in chromosomes and, within these domains, facilitates interactions between transcription regulatory sequences. Thus, CTCF links the architecture of the genome to its function.
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Affiliation(s)
- Chin-Tong Ong
- Department of Biology, Emory University, 1510 Clifton Rd NE, Atlanta, Georgia 30322, USA
| | - Victor G Corces
- Department of Biology, Emory University, 1510 Clifton Rd NE, Atlanta, Georgia 30322, USA
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40
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Atkinson TJ, Halfon MS. Regulation of gene expression in the genomic context. Comput Struct Biotechnol J 2014; 9:e201401001. [PMID: 24688749 PMCID: PMC3962188 DOI: 10.5936/csbj.201401001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 12/10/2013] [Accepted: 12/29/2013] [Indexed: 11/22/2022] Open
Abstract
Metazoan life is dependent on the proper temporal and spatial control of gene expression within the many cells-essentially all with the identical genome-that make up the organism. While much is understood about how individual gene regulatory elements function, many questions remain about how they interact to maintain correct regulation globally throughout the genome. In this review we summarize the basic features and functions of the crucial regulatory elements promoters, enhancers, and insulators and discuss some of the ways in which proper interactions between these elements is realized. We focus in particular on the role of core promoter sequences and propose explanations for some of the contradictory results seen in experiments aimed at understanding insulator function. We suggest that gene regulation depends on local genomic context and argue that more holistic in vivo investigations that take into account multiple local features will be necessary to understand how genome-wide gene regulation is maintained.
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Affiliation(s)
- Taylor J Atkinson
- Department of Biochemistry, University at Buffalo-State University of New York, Buffalo, NY 14203, USA
- NY State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, NY 14203, USA
| | - Marc S Halfon
- Department of Biochemistry, University at Buffalo-State University of New York, Buffalo, NY 14203, USA
- Department of Biological Sciences, University at Buffalo-State University of New York, Buffalo, NY 14203, USA
- NY State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, NY 14203, USA
- Molecular and Cellular Biology Department and Program in Cancer Genetics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
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41
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Ichiyanagi K. Epigenetic regulation of transcription and possible functions of mammalian short interspersed elements, SINEs. Genes Genet Syst 2014; 88:19-29. [PMID: 23676707 DOI: 10.1266/ggs.88.19] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Short interspersed elements (SINEs) are a class of retrotransposons, which amplify their copy numbers in their host genomes by retrotransposition. More than a million copies of SINEs are present in a mammalian genome, constituting over 10% of the total genomic sequence. In contrast to the other two classes of retrotransposons, long interspersed elements (LINEs) and long terminal repeat (LTR) elements, SINEs are transcribed by RNA polymerase III. However, like LINEs and LTR elements, the SINE transcription is likely regulated by epigenetic mechanisms such as DNA methylation, at least for human Alu and mouse B1. Whereas SINEs and other transposable elements have long been thought as selfish or junk DNA, recent studies have revealed that they play functional roles at their genomic locations, for example, as distal enhancers, chromatin boundaries and binding sites of many transcription factors. These activities imply that SINE retrotransposition has shaped the regulatory network and chromatin landscape of their hosts. Whereas it is thought that the epigenetic mechanisms were originated as a host defense system against proliferation of parasitic elements, this review discusses a possibility that the same mechanisms are also used to regulate the SINE-derived functions.
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Affiliation(s)
- Kenji Ichiyanagi
- Division of Epigenomics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
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42
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Alla RK, Cairns BR. RNA polymerase III transcriptomes in human embryonic stem cells and induced pluripotent stem cells, and relationships with pluripotency transcription factors. PLoS One 2014; 9:e85648. [PMID: 24465633 PMCID: PMC3896398 DOI: 10.1371/journal.pone.0085648] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 11/29/2013] [Indexed: 01/03/2023] Open
Abstract
Recent genomic approaches have revealed that the repertoire of RNA Pol III-transcribed genes varies in different human cell types, and that this variation is likely determined by a combination of the chromatin landscape, cell-specific DNA-binding transcription factors, and collaboration with RNA Pol II. Although much is known about this regulation in differentiated human cells, there is presently little understanding of this aspect of the Pol III system in human ES cells. Here, we determine the occupancy profiles of Pol III components in human H1 ES cells, and also induced pluripotent cells, and compare to known profiles of chromatin, transcription factors, and RNA expression. We find a relatively large fraction of the Pol III repertoire occupied in human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs). In ES cells we find clear correlations between Pol III occupancy and active chromatin. Interestingly, we find a highly significant fraction of Pol III-occupied genes with adjacent binding events by pluripotency factors in ES cells, especially NANOG. Notably, in human ES cells we find H3K27me3 adjacent to but not overlapping many active Pol III loci. We observe in all such cases, a peak of H3K4me3 and/or RNA Pol II, between the H3K27me3 and Pol III binding peaks, suggesting that H3K4me3 and Pol II activity may "insulate" Pol III from neighboring repressive H3K27me3. Further, we find iPSCs have a larger Pol III repertoire than their precursors. Finally, the active Pol III genome in iPSCs is not completely reprogrammed to a hESC like state and partially retains the transcriptional repertoire of the precursor. Together, our correlative results are consistent with Pol III binding and activity in human ES cells being enabled by active/permissive chromatin that is shaped in part by the pluripotency network of transcription factors and RNA Pol II activity.
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Affiliation(s)
- Ravi K. Alla
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Bradley R. Cairns
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail:
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43
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Renaud M, Praz V, Vieu E, Florens L, Washburn MP, l'Hôte P, Hernandez N. Gene duplication and neofunctionalization: POLR3G and POLR3GL. Genome Res 2013; 24:37-51. [PMID: 24107381 PMCID: PMC3875860 DOI: 10.1101/gr.161570.113] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
RNA polymerase III (Pol III) occurs in two versions, one containing the POLR3G subunit and the other the closely related POLR3GL subunit. It is not clear whether these two Pol III forms have the same function, in particular whether they recognize the same target genes. We show that the POLR3G and POLR3GL genes arose from a DNA-based gene duplication, probably in a common ancestor of vertebrates. POLR3G- as well as POLR3GL-containing Pol III are present in cultured cell lines and in normal mouse liver, although the relative amounts of the two forms vary, with the POLR3G-containing Pol III relatively more abundant in dividing cells. Genome-wide chromatin immunoprecipitations followed by high-throughput sequencing (ChIP-seq) reveal that both forms of Pol III occupy the same target genes, in very constant proportions within one cell line, suggesting that the two forms of Pol III have a similar function with regard to specificity for target genes. In contrast, the POLR3G promoter—not the POLR3GL promoter—binds the transcription factor MYC, as do all other promoters of genes encoding Pol III subunits. Thus, the POLR3G/POLR3GL duplication did not lead to neo-functionalization of the gene product (at least with regard to target gene specificity) but rather to neo-functionalization of the transcription units, which acquired different mechanisms of regulation, thus likely affording greater regulation potential to the cell.
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Affiliation(s)
- Marianne Renaud
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
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44
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Venters BJ, Pugh BF. Genomic organization of human transcription initiation complexes. Nature 2013; 502:53-8. [PMID: 24048476 PMCID: PMC4018585 DOI: 10.1038/nature12535] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 08/09/2013] [Indexed: 11/16/2022]
Abstract
The human genome is pervasively transcribed, yet only a small fraction is coding. Here we address whether this noncoding transcription arises at promoters, and detail the interactions of initiation factors TBP, TFIIB, and RNA polymerase (Pol) II. Using ChIP-exo, we identify ~160,000 transcription initiation complexes across the human K562 genome, and more in other cancer genomes. Only ~5% associate with mRNA genes. The remaining associate with non-polyadenylated noncoding transcription. Regardless, Pol II moves into a transcriptionally paused state, and TBP/TFIIB remain at the promoter. Remarkably, the vast majority of locations contain the four core promoter elements: BREu, TATA, BREd, and INR, in constrained positions. All but the INR also reside at Pol III promoters, where TBP makes similar contacts. This comprehensive and high resolution genome-wide detection of the initiation machinery produces a consolidated view of transcription initiation events from yeast to humans at Pol II/III TATA-containing/TATA-less coding and noncoding genes.
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Affiliation(s)
- Bryan J Venters
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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45
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Genomic and proteomic analyses of Prdm5 reveal interactions with insulator binding proteins in embryonic stem cells. Mol Cell Biol 2013; 33:4504-16. [PMID: 24043305 DOI: 10.1128/mcb.00545-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PRDM proteins belong to the SET domain protein family, which is involved in the regulation of gene expression. Although few PRDM members possess histone methyltransferase activity, the molecular mechanisms by which the other members exert transcriptional regulation remain to be delineated. In this study, we find that Prdm5 is highly expressed in mouse embryonic stem (mES) cells and exploit this cellular system to characterize molecular functions of Prdm5. By combining proteomics and next-generation sequencing technologies, we identify Prdm5 interaction partners and genomic occupancy. We demonstrate that although Prdm5 is dispensable for mES cell maintenance, it directly targets genomic regions involved in early embryonic development and affects the expression of a subset of developmental regulators during cell differentiation. Importantly, Prdm5 interacts with Ctcf, cohesin, and TFIIIC and cooccupies genomic loci. In summary, our data indicate how Prdm5 modulates transcription by interacting with factors involved in genome organization in mouse embryonic stem cells.
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46
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Binding of TFIIIC to sine elements controls the relocation of activity-dependent neuronal genes to transcription factories. PLoS Genet 2013; 9:e1003699. [PMID: 23966877 PMCID: PMC3744447 DOI: 10.1371/journal.pgen.1003699] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 06/20/2013] [Indexed: 12/31/2022] Open
Abstract
In neurons, the timely and accurate expression of genes in response to synaptic activity relies on the interplay between epigenetic modifications of histones, recruitment of regulatory proteins to chromatin and changes to nuclear structure. To identify genes and regulatory elements responsive to synaptic activation in vivo, we performed a genome-wide ChIPseq analysis of acetylated histone H3 using somatosensory cortex of mice exposed to novel enriched environmental (NEE) conditions. We discovered that Short Interspersed Elements (SINEs) located distal to promoters of activity-dependent genes became acetylated following exposure to NEE and were bound by the general transcription factor TFIIIC. Importantly, under depolarizing conditions, inducible genes relocated to transcription factories (TFs), and this event was controlled by TFIIIC. Silencing of the TFIIIC subunit Gtf3c5 in non-stimulated neurons induced uncontrolled relocation to TFs and transcription of activity-dependent genes. Remarkably, in cortical neurons, silencing of Gtf3c5 mimicked the effects of chronic depolarization, inducing a dramatic increase of both dendritic length and branching. These findings reveal a novel and essential regulatory function of both SINEs and TFIIIC in mediating gene relocation and transcription. They also suggest that TFIIIC may regulate the rearrangement of nuclear architecture, allowing the coordinated expression of activity-dependent neuronal genes. In neurons, acetylation of histones and other epigenetic modifications influence gene expression in response to synaptic activity. Genes that are concomitantly expressed in response to stimulation are transcribed at specific nuclear foci, known as transcription factories (TFs) that are enriched with active RNA Polymerase II and often include specific transcription factors. Here, we show a novel regulatory role for Short Interspersed Elements (SINEs) located in the proximity of activity-regulated genes. SINEs represent a new class of regulatory sequences that function as coordinators of depolarization-dependent transcription. Binding of the general transcription factor TFIIIC to SINEs regulates activity-dependent transcription, relocation of inducible genes to transcription factories and dendritogenesis. Our study provides new fundamental insights into the mechanisms by which relocation of inducible genes to transcription factories and changes of nuclear architecture coordinate the transcriptional program in response to neuronal activity.
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47
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Livyatan I, Harikumar A, Nissim-Rafinia M, Duttagupta R, Gingeras TR, Meshorer E. Non-polyadenylated transcription in embryonic stem cells reveals novel non-coding RNA related to pluripotency and differentiation. Nucleic Acids Res 2013; 41:6300-15. [PMID: 23630323 PMCID: PMC3695530 DOI: 10.1093/nar/gkt316] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The transcriptional landscape in embryonic stem cells (ESCs) and during ESC differentiation has received considerable attention, albeit mostly confined to the polyadenylated fraction of RNA, whereas the non-polyadenylated (NPA) fraction remained largely unexplored. Notwithstanding, the NPA RNA super-family has every potential to participate in the regulation of pluripotency and stem cell fate. We conducted a comprehensive analysis of NPA RNA in ESCs using a combination of whole-genome tiling arrays and deep sequencing technologies. In addition to identifying previously characterized and new non-coding RNA members, we describe a group of novel conserved RNAs (snacRNAs: small NPA conserved), some of which are differentially expressed between ESC and neuronal progenitor cells, providing the first evidence of a novel group of potentially functional NPA RNA involved in the regulation of pluripotency and stem cell fate. We further show that minor spliceosomal small nuclear RNAs, which are NPA, are almost completely absent in ESCs and are upregulated in differentiation. Finally, we show differential processing of the minor intron of the polycomb group gene Eed. Our data suggest that NPA RNA, both known and novel, play important roles in ESCs.
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48
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Chaveroux C, Eichner LJ, Dufour CR, Shatnawi A, Khoutorsky A, Bourque G, Sonenberg N, Giguère V. Molecular and genetic crosstalks between mTOR and ERRα are key determinants of rapamycin-induced nonalcoholic fatty liver. Cell Metab 2013; 17:586-98. [PMID: 23562079 DOI: 10.1016/j.cmet.2013.03.003] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 11/16/2012] [Accepted: 03/06/2013] [Indexed: 10/27/2022]
Abstract
mTOR and ERRα are key regulators of common metabolic processes, including lipid homeostasis. However, it is currently unknown whether these factors cooperate in the control of metabolism. ChIP-sequencing analyses of mouse liver reveal that mTOR occupies regulatory regions of genes on a genome-wide scale including enrichment at genes shared with ERRα that are involved in the TCA cycle and lipid biosynthesis. Genetic ablation of ERRα and rapamycin treatment, alone or in combination, alter the expression of these genes and induce the accumulation of TCA metabolites. As a consequence, both genetic and pharmacological inhibition of ERRα activity exacerbates hepatic hyperlipidemia observed in rapamycin-treated mice. We further show that mTOR regulates ERRα activity through ubiquitin-mediated degradation via transcriptional control of the ubiquitin-proteasome pathway. Our work expands the role of mTOR action in metabolism and highlights the existence of a potent mTOR/ERRα regulatory axis with significant clinical impact.
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Affiliation(s)
- Cédric Chaveroux
- Rosalind and Morris Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue West, Montréal, QC H3A 1A3, Canada
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49
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Van Bortle K, Corces VG. The role of chromatin insulators in nuclear architecture and genome function. Curr Opin Genet Dev 2013; 23:212-8. [PMID: 23298659 DOI: 10.1016/j.gde.2012.11.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 11/08/2012] [Indexed: 10/27/2022]
Abstract
Eukaryotic genomes are intricately arranged into highly organized yet dynamic structures that underlie patterns of gene expression and cellular identity. The recent adaptation of novel genomic strategies for assaying nuclear architecture has significantly extended and accelerated our ability to query the nature of genome organization and the players involved. In particular, recent explorations of physical arrangements and chromatin landscapes in higher eukaryotes have demonstrated that chromatin insulators, which mediate functional interactions between regulatory elements, appear to play an important role in these processes. Here we reflect on current findings and our rapidly expanding understanding of insulators and their role in nuclear architecture and genome function.
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Affiliation(s)
- Kevin Van Bortle
- Department of Biology, Emory University, Atlanta, GA 30322, United States
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50
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Moir RD, Willis IM. Regulation of pol III transcription by nutrient and stress signaling pathways. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1829:361-75. [PMID: 23165150 DOI: 10.1016/j.bbagrm.2012.11.001] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 11/06/2012] [Accepted: 11/08/2012] [Indexed: 12/29/2022]
Abstract
Transcription by RNA polymerase III (pol III) is responsible for ~15% of total cellular transcription through the generation of small structured RNAs such as tRNA and 5S RNA. The coordinate synthesis of these molecules with ribosomal protein mRNAs and rRNA couples the production of ribosomes and their tRNA substrates and balances protein synthetic capacity with the growth requirements of the cell. Ribosome biogenesis in general and pol III transcription in particular is known to be regulated by nutrient availability, cell stress and cell cycle stage and is perturbed in pathological states. High throughput proteomic studies have catalogued modifications to pol III subunits, assembly, initiation and accessory factors but most of these modifications have yet to be linked to functional consequences. Here we review our current understanding of the major points of regulation in the pol III transcription apparatus, the targets of regulation and the signaling pathways known to regulate their function. This article is part of a Special Issue entitled: Transcription by Odd Pols.
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Affiliation(s)
- Robyn D Moir
- Departments of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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