1
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Struhl K. Non-canonical functions of enhancers: regulation of RNA polymerase III transcription, DNA replication, and V(D)J recombination. Trends Genet 2024; 40:471-479. [PMID: 38643034 PMCID: PMC11152991 DOI: 10.1016/j.tig.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/02/2024] [Indexed: 04/22/2024]
Abstract
Enhancers are the key regulators of other DNA-based processes by virtue of their unique ability to generate nucleosome-depleted regions in a highly regulated manner. Enhancers regulate cell-type-specific transcription of tRNA genes by RNA polymerase III (Pol III). They are also responsible for the binding of the origin replication complex (ORC) to DNA replication origins, thereby regulating origin utilization, replication timing, and replication-dependent chromosome breaks. Additionally, enhancers regulate V(D)J recombination by increasing access of the recombination-activating gene (RAG) recombinase to target sites and by generating non-coding enhancer RNAs and localized regions of trimethylated histone H3-K4 recognized by the RAG2 PHD domain. Thus, enhancers represent the first step in decoding the genome, and hence they regulate biological processes that, unlike RNA polymerase II (Pol II) transcription, do not have dedicated regulatory proteins.
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Affiliation(s)
- Kevin Struhl
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
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2
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Van Bortle K, Marciano DP, Liu Q, Chou T, Lipchik AM, Gollapudi S, Geller BS, Monte E, Kamakaka RT, Snyder MP. A cancer-associated RNA polymerase III identity drives robust transcription and expression of snaR-A noncoding RNA. Nat Commun 2022; 13:3007. [PMID: 35637192 PMCID: PMC9151912 DOI: 10.1038/s41467-022-30323-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 04/13/2022] [Indexed: 11/09/2022] Open
Abstract
RNA polymerase III (Pol III) includes two alternate isoforms, defined by mutually exclusive incorporation of subunit POLR3G (RPC7α) or POLR3GL (RPC7β), in mammals. The contributions of POLR3G and POLR3GL to transcription potential has remained poorly defined. Here, we discover that loss of subunit POLR3G is accompanied by a restricted repertoire of genes transcribed by Pol III. Particularly sensitive is snaR-A, a small noncoding RNA implicated in cancer proliferation and metastasis. Analysis of Pol III isoform biases and downstream chromatin features identifies loss of POLR3G and snaR-A during differentiation, and conversely, re-establishment of POLR3G gene expression and SNAR-A gene features in cancer contexts. Our results support a model in which Pol III identity functions as an important transcriptional regulatory mechanism. Upregulation of POLR3G, which is driven by MYC, identifies a subgroup of patients with unfavorable survival outcomes in specific cancers, further implicating the POLR3G-enhanced transcription repertoire as a potential disease factor. RNA polymerase III changes its subunit composition during mammalian development. Here the authors report that loss of subunit POLR3G, which re-emerges in cancer, promotes expression of small NF90-associated RNA (snaR-A), a noncoding RNA implicated in cell proliferation and metastasis.
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3
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Hassanaly-Goulamhoussen R, De Carvalho Augusto R, Marteu-Garello N, Péré A, Favery B, Da Rocha M, Danchin EGJ, Abad P, Grunau C, Perfus-Barbeoch L. Chromatin Landscape Dynamics in the Early Development of the Plant Parasitic Nematode Meloidogyne incognita. Front Cell Dev Biol 2021; 9:765690. [PMID: 34938734 PMCID: PMC8685519 DOI: 10.3389/fcell.2021.765690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/03/2021] [Indexed: 11/17/2022] Open
Abstract
In model organisms, epigenome dynamics underlies a plethora of biological processes. The role of epigenetic modifications in development and parasitism in nematode pests remains unknown. The root-knot nematode Meloidogyne incognita adapts rapidly to unfavorable conditions, despite its asexual reproduction. However, the mechanisms underlying this remarkable plasticity and their potential impact on gene expression remain unknown. This study provides the first insight into contribution of epigenetic mechanisms to this plasticity, by studying histone modifications in M. incognita. The distribution of five histone modifications revealed the existence of strong epigenetic signatures, similar to those found in the model nematode Caenorhabditis elegans. We investigated their impact on chromatin structure and their distribution relative to transposable elements (TE) loci. We assessed the influence of the chromatin landscape on gene expression at two developmental stages: eggs, and pre-parasitic juveniles. H3K4me3 histone modification was strongly correlated with high levels of expression for protein-coding genes implicated in stage-specific processes during M. incognita development. We provided new insights in the dynamic regulation of parasitism genes kept under histone modifications silencing. In this pioneering study, we establish a comprehensive framework for the importance of epigenetic mechanisms in the regulation of the genome expression and its stability in plant-parasitic nematodes.
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Affiliation(s)
| | - Ronaldo De Carvalho Augusto
- IHPE, Univ Perpignan Via Domitia, CNRS, IFREMER, Univ Montpellier, Perpignan, France.,Laboratory of Biology and Modeling of the Cell, Ecole Normale Supérieure de Lyon, CNRS, Université Claude Bernard de Lyon, Université de Lyon, Lyon, France
| | | | - Arthur Péré
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis, France
| | - Bruno Favery
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis, France
| | - Martine Da Rocha
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis, France
| | | | - Pierre Abad
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis, France
| | - Christoph Grunau
- IHPE, Univ Perpignan Via Domitia, CNRS, IFREMER, Univ Montpellier, Perpignan, France
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4
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Kulaberoglu Y, Malik Y, Borland G, Selman C, Alic N, Tullet JMA. RNA Polymerase III, Ageing and Longevity. Front Genet 2021; 12:705122. [PMID: 34295356 PMCID: PMC8290157 DOI: 10.3389/fgene.2021.705122] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 06/14/2021] [Indexed: 11/13/2022] Open
Abstract
Transcription in eukaryotic cells is performed by three RNA polymerases. RNA polymerase I synthesises most rRNAs, whilst RNA polymerase II transcribes all mRNAs and many non-coding RNAs. The largest of the three polymerases is RNA polymerase III (Pol III) which transcribes a variety of short non-coding RNAs including tRNAs and the 5S rRNA, in addition to other small RNAs such as snRNAs, snoRNAs, SINEs, 7SL RNA, Y RNA, and U6 spilceosomal RNA. Pol III-mediated transcription is highly dynamic and regulated in response to changes in cell growth, cell proliferation and stress. Pol III-generated transcripts are involved in a wide variety of cellular processes, including translation, genome and transcriptome regulation and RNA processing, with Pol III dys-regulation implicated in diseases including leukodystrophy, Alzheimer's, Fragile X-syndrome and various cancers. More recently, Pol III was identified as an evolutionarily conserved determinant of organismal lifespan acting downstream of mTORC1. Pol III inhibition extends lifespan in yeast, worms and flies, and in worms and flies acts from the intestine and intestinal stem cells respectively to achieve this. Intriguingly, Pol III activation achieved through impairment of its master repressor, Maf1, has also been shown to promote longevity in model organisms, including mice. In this review we introduce the Pol III transcription apparatus and review the current understanding of RNA Pol III's role in ageing and lifespan in different model organisms. We then discuss the potential of Pol III as a therapeutic target to improve age-related health in humans.
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Affiliation(s)
- Yavuz Kulaberoglu
- Department of Genetics Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Yasir Malik
- Faculty of Natural Sciences, University of Kent, Canterbury, United Kingdom
| | - Gillian Borland
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Colin Selman
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Nazif Alic
- Department of Genetics Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
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5
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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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6
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Roles for the RNA polymerase III regulator MAFR-1 in regulating sperm quality in Caenorhabditis elegans. Sci Rep 2020; 10:19367. [PMID: 33168938 PMCID: PMC7652826 DOI: 10.1038/s41598-020-76423-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 10/27/2020] [Indexed: 11/08/2022] Open
Abstract
The negative regulator of RNA polymerase (pol) III mafr-1 has been shown to affect RNA pol III transcript abundance, lipid biosynthesis and storage, progeny output, and lifespan. We deleted mafr-1 from the Caenorhabditis elegans genome and found that animals lacking mafr-1 replicated many phenotypes from previous RNAi-based studies and discovered a new sperm-specific role. Utilizing a yeast two-hybrid assay, we discovered several novel interactors of MAFR-1 that are expressed in a sperm- and germline-enriched manner. In support of a role for MAFR-1 in the male germline, we found mafr-1 null males have smaller spermatids that are less capable in competition for fertilization; a phenotype that was dependent on RNA pol III activity. Restoration of MAFR-1 expression specifically in the germline rescued the spermatid-related phenotypes, suggesting a cell autonomous role for MAFR-1 in nematode male fertility. Based on the high degree of conservation of Maf1 activity across species, our study may inform similar roles for Maf1 and RNA pol III in mammalian male fertility.
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7
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Abstract
In this review, Yeganeh et al. summarize different human diseases that have been linked to defects in the Pol III transcription apparatus or to Pol III products imbalance and discuss the possible underlying mechanisms. RNA polymerase (Pol) III is responsible for transcription of different noncoding genes in eukaryotic cells, whose RNA products have well-defined functions in translation and other biological processes for some, and functions that remain to be defined for others. For all of them, however, new functions are being described. For example, Pol III products have been reported to regulate certain proteins such as protein kinase R (PKR) by direct association, to constitute the source of very short RNAs with regulatory roles in gene expression, or to control microRNA levels by sequestration. Consistent with these many functions, deregulation of Pol III transcribed genes is associated with a large variety of human disorders. Here we review different human diseases that have been linked to defects in the Pol III transcription apparatus or to Pol III products imbalance and discuss the possible underlying mechanisms.
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Affiliation(s)
- Meghdad Yeganeh
- 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
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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: 20] [Impact Index Per Article: 5.0] [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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9
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TDP-43 regulates transcription at protein-coding genes and Alu retrotransposons. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194434. [PMID: 31655156 DOI: 10.1016/j.bbagrm.2019.194434] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 12/13/2022]
Abstract
The 43-kDa transactive response DNA-binding protein (TDP-43) is an example of an RNA-binding protein that regulates RNA metabolism at multiple levels from transcription and splicing to translation. Its role in post-transcriptional RNA processing has been a primary focus of recent research, but its role in regulating transcription has been studied for only a few human genes. We characterized the effects of TDP-43 on transcription genome-wide and found that TDP-43 broadly affects transcription of protein-coding and noncoding RNA genes. Among protein-coding genes, the effects of TDP-43 were greatest for genes <30 thousand base pairs in length. Surprisingly, we found that the loss of TDP-43 resulted in increased evidence for transcription activity near repetitive Alu elements found within expressed genes. The highest densities of affected Alu elements were found in the shorter genes, whose transcription was most affected by TDP-43. Thus, in addition to its role in post-transcriptional RNA processing, TDP-43 plays a critical role in maintaining the transcriptional stability of protein-coding genes and transposable DNA elements.
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10
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Yeganeh M, Praz V, Carmeli C, Villeneuve D, Rib L, Guex N, Herr W, Delorenzi M, Hernandez N. Differential regulation of RNA polymerase III genes during liver regeneration. Nucleic Acids Res 2019; 47:1786-1796. [PMID: 30597109 PMCID: PMC6393285 DOI: 10.1093/nar/gky1282] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/22/2018] [Accepted: 12/14/2018] [Indexed: 12/23/2022] Open
Abstract
Mouse liver regeneration after partial hepatectomy involves cells in the remaining tissue synchronously entering the cell division cycle. We have used this system and H3K4me3, Pol II and Pol III profiling to characterize adaptations in Pol III transcription. Our results broadly define a class of genes close to H3K4me3 and Pol II peaks, whose Pol III occupancy is high and stable, and another class, distant from Pol II peaks, whose Pol III occupancy strongly increases after partial hepatectomy. Pol III regulation in the liver thus entails both highly expressed housekeeping genes and genes whose expression can adapt to increased demand.
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Affiliation(s)
- Meghdad Yeganeh
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Viviane Praz
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland.,SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Cristian Carmeli
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland.,Bioinformatics Core Facility, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Dominic Villeneuve
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Leonor Rib
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Nicolas Guex
- SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Winship Herr
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Mauro Delorenzi
- Bioinformatics Core Facility, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland.,Department of Fundamental Oncology and the Ludwig Center for Cancer research, 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
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11
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Berg MD, Giguere DJ, Dron JS, Lant JT, Genereaux J, Liao C, Wang J, Robinson JF, Gloor GB, Hegele RA, O'Donoghue P, Brandl CJ. Targeted sequencing reveals expanded genetic diversity of human transfer RNAs. RNA Biol 2019; 16:1574-1585. [PMID: 31407949 PMCID: PMC6779403 DOI: 10.1080/15476286.2019.1646079] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Transfer RNAs are required to translate genetic information into proteins as well as regulate other cellular processes. Nucleotide changes in tRNAs can result in loss or gain of function that impact the composition and fidelity of the proteome. Despite links between tRNA variation and disease, the importance of cytoplasmic tRNA variation has been overlooked. Using a custom capture panel, we sequenced 605 human tRNA-encoding genes from 84 individuals. We developed a bioinformatic pipeline that allows more accurate tRNA read mapping and identifies multiple polymorphisms occurring within the same variant. Our analysis identified 522 unique tRNA-encoding sequences that differed from the reference genome from 84 individuals. Each individual had ~66 tRNA variants including nine variants found in less than 5% of our sample group. Variants were identified throughout the tRNA structure with 17% predicted to enhance function. Eighteen anticodon mutants were identified including potentially mistranslating tRNAs; e.g., a tRNASer that decodes Phe codons. Similar engineered tRNA variants were previously shown to inhibit cell growth, increase apoptosis and induce the unfolded protein response in mammalian cell cultures and chick embryos. Our analysis shows that human tRNA variation has been underestimated. We conclude that the large number of tRNA genes provides a buffer enabling the emergence of variants, some of which could contribute to disease.
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Affiliation(s)
- Matthew D Berg
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
| | - Daniel J Giguere
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
| | - Jacqueline S Dron
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada.,Robarts Research Institute, The University of Western Ontario , London , ON , Canada
| | - Jeremy T Lant
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
| | - Julie Genereaux
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
| | - Calwing Liao
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada.,Robarts Research Institute, The University of Western Ontario , London , ON , Canada
| | - Jian Wang
- Robarts Research Institute, The University of Western Ontario , London , ON , Canada
| | - John F Robinson
- Robarts Research Institute, The University of Western Ontario , London , ON , Canada
| | - Gregory B Gloor
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
| | - Robert A Hegele
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada.,Robarts Research Institute, The University of Western Ontario , London , ON , Canada.,Department of Medicine, The University of Western Ontario , London , ON , Canada
| | - Patrick O'Donoghue
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada.,Department of Chemistry, The University of Western Ontario , London , ON , Canada
| | - Christopher J Brandl
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
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12
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Choquet K, Forget D, Meloche E, Dicaire MJ, Bernard G, Vanderver A, Schiffmann R, Fabian MR, Teichmann M, Coulombe B, Brais B, Kleinman CL. Leukodystrophy-associated POLR3A mutations down-regulate the RNA polymerase III transcript and important regulatory RNA BC200. J Biol Chem 2019; 294:7445-7459. [PMID: 30898877 PMCID: PMC6509492 DOI: 10.1074/jbc.ra118.006271] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 03/07/2019] [Indexed: 12/12/2022] Open
Abstract
RNA polymerase III (Pol III) is an essential enzyme responsible for the synthesis of several small noncoding RNAs, a number of which are involved in mRNA translation. Recessive mutations in POLR3A, encoding the largest subunit of Pol III, cause POLR3-related hypomyelinating leukodystrophy (POLR3–HLD), characterized by deficient central nervous system myelination. Identification of the downstream effectors of pathogenic POLR3A mutations has so far been elusive. Here, we used CRISPR-Cas9 to introduce the POLR3A mutation c.2554A→G (p.M852V) into human cell lines and assessed its impact on Pol III biogenesis, nuclear import, DNA occupancy, transcription, and protein levels. Transcriptomic profiling uncovered a subset of transcripts vulnerable to Pol III hypofunction, including a global reduction in tRNA levels. The brain cytoplasmic BC200 RNA (BCYRN1), involved in translation regulation, was consistently affected in all our cellular models, including patient-derived fibroblasts. Genomic BC200 deletion in an oligodendroglial cell line led to major transcriptomic and proteomic changes, having a larger impact than those of POLR3A mutations. Upon differentiation, mRNA levels of the MBP gene, encoding myelin basic protein, were significantly decreased in POLR3A-mutant cells. Our findings provide the first evidence for impaired Pol III transcription in cellular models of POLR3–HLD and identify several candidate effectors, including BC200 RNA, having a potential role in oligodendrocyte biology and involvement in the disease.
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Affiliation(s)
- Karine Choquet
- From the Department of Human Genetics, McGill University, Montréal, Québec H3A 0C7, Canada.,the Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec H3T 1E2, Canada.,the Montréal Neurological Institute, McGill University, Montréal, Québec H3A 2B4, Canada
| | - Diane Forget
- the Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montréal, Québec H2W 1R7, Canada
| | - Elisabeth Meloche
- the Montréal Neurological Institute, McGill University, Montréal, Québec H3A 2B4, Canada
| | - Marie-Josée Dicaire
- the Montréal Neurological Institute, McGill University, Montréal, Québec H3A 2B4, Canada
| | - Geneviève Bernard
- From the Department of Human Genetics, McGill University, Montréal, Québec H3A 0C7, Canada.,Pediatrics, McGill University, Montréal, Québec H3A 0G4, Canada.,the Department of Internal Medicine, Division of Medical Genetics, Montréal Children's Hospital, McGill University Health Center, Montréal, Québec H4A 3J1, Canada.,the Child Health and Human Development Program, and.,MyeliNeuroGene Laboratory, Research Institute, McGill University Health Center, Montréal, Québec H4A 3J1, Canada.,the Departments of Neurology and Neurosurgery and
| | - Adeline Vanderver
- the Division of Neurology, Children's Hospital of Philadelphia (CHOP), Philadelphia, Pennsylvania 19104
| | - Raphael Schiffmann
- the Institute of Metabolic Disease, Baylor Research Institute, Dallas, Texas 75204
| | - Marc R Fabian
- the Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec H3T 1E2, Canada
| | - Martin Teichmann
- INSERM U1212-CNRS UMR5320, Université de Bordeaux, Bordeaux, France, and
| | - Benoit Coulombe
- the Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montréal, Québec H2W 1R7, Canada.,the Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Bernard Brais
- From the Department of Human Genetics, McGill University, Montréal, Québec H3A 0C7, Canada.,the Montréal Neurological Institute, McGill University, Montréal, Québec H3A 2B4, Canada.,the Departments of Neurology and Neurosurgery and
| | - Claudia L Kleinman
- From the Department of Human Genetics, McGill University, Montréal, Québec H3A 0C7, Canada, .,the Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec H3T 1E2, Canada
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13
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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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14
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Lund RJ, Rahkonen N, Malonzo M, Kauko L, Emani MR, Kivinen V, Närvä E, Kemppainen E, Laiho A, Skottman H, Hovatta O, Rasool O, Nykter M, Lähdesmäki H, Lahesmaa R. RNA Polymerase III Subunit POLR3G Regulates Specific Subsets of PolyA + and SmallRNA Transcriptomes and Splicing in Human Pluripotent Stem Cells. Stem Cell Reports 2018; 8:1442-1454. [PMID: 28494942 PMCID: PMC5425787 DOI: 10.1016/j.stemcr.2017.04.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 04/13/2017] [Accepted: 04/13/2017] [Indexed: 11/17/2022] Open
Abstract
POLR3G is expressed at high levels in human pluripotent stem cells (hPSCs) and is required for maintenance of stem cell state through mechanisms not known in detail. To explore how POLR3G regulates stem cell state, we carried out deep-sequencing analysis of polyA+ and smallRNA transcriptomes present in hPSCs and regulated in POLR3G-dependent manner. Our data reveal that POLR3G regulates a specific subset of the hPSC transcriptome, including multiple transcript types, such as protein-coding genes, long intervening non-coding RNAs, microRNAs and small nucleolar RNAs, and affects RNA splicing. The primary function of POLR3G is in the maintenance rather than repression of transcription. The majority of POLR3G polyA+ transcriptome is regulated during differentiation, and the key pluripotency factors bind to the promoters of at least 30% of the POLR3G-regulated transcripts. Among the direct targets of POLR3G, POLG is potentially important in sustaining stem cell status in a POLR3G-dependent manner.
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Affiliation(s)
- Riikka J Lund
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20520, Finland.
| | - Nelly Rahkonen
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20520, Finland
| | - Maia Malonzo
- Department of Computer Science, Aalto University, Espoo 02150, Finland
| | - Leni Kauko
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20520, Finland
| | - Maheswara Reddy Emani
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20520, Finland
| | - Virpi Kivinen
- Faculty of Medicine and Life Sciences, BioMediTech, University of Tampere, Tampere 33014, Finland
| | - Elisa Närvä
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20520, Finland
| | - Esko Kemppainen
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20520, Finland
| | - Asta Laiho
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20520, Finland
| | - Heli Skottman
- Faculty of Medicine and Life Sciences, BioMediTech, University of Tampere, Tampere 33014, Finland
| | - Outi Hovatta
- Department CLINTEC, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm 171 77, Sweden
| | - Omid Rasool
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20520, Finland
| | - Matti Nykter
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20520, Finland; Faculty of Medicine and Life Sciences, BioMediTech, University of Tampere, Tampere 33014, Finland
| | - Harri Lähdesmäki
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20520, Finland; Department of Computer Science, Aalto University, Espoo 02150, Finland
| | - Riitta Lahesmaa
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20520, Finland
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15
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Willis IM, Moir RD. Signaling to and from the RNA Polymerase III Transcription and Processing Machinery. Annu Rev Biochem 2018; 87:75-100. [PMID: 29328783 DOI: 10.1146/annurev-biochem-062917-012624] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
RNA polymerase (Pol) III has a specialized role in transcribing the most abundant RNAs in eukaryotic cells, transfer RNAs (tRNAs), along with other ubiquitous small noncoding RNAs, many of which have functions related to the ribosome and protein synthesis. The high energetic cost of producing these RNAs and their central role in protein synthesis underlie the robust regulation of Pol III transcription in response to nutrients and stress by growth regulatory pathways. Downstream of Pol III, signaling impacts posttranscriptional processes affecting tRNA function in translation and tRNA cleavage into smaller fragments that are increasingly attributed with novel cellular activities. In this review, we consider how nutrients and stress control Pol III transcription via its factors and its negative regulator, Maf1. We highlight recent work showing that the composition of the tRNA population and the function of individual tRNAs is dynamically controlled and that unrestrained Pol III transcription can reprogram central metabolic pathways.
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Affiliation(s)
- Ian M Willis
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA; , .,Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Robyn D Moir
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA; ,
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16
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Shukla A, Bhargava P. Regulation of tRNA gene transcription by the chromatin structure and nucleosome dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1861:295-309. [PMID: 29313808 DOI: 10.1016/j.bbagrm.2017.11.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 11/27/2017] [Accepted: 11/27/2017] [Indexed: 01/19/2023]
Abstract
The short, non-coding genes transcribed by the RNA polymerase (pol) III, necessary for survival of a cell, need to be repressed under the stress conditions in vivo. The pol III-transcribed genes have adopted several novel chromatin-based regulatory mechanisms to their advantage. In the budding yeast, the sub-nucleosomal size tRNA genes are found in the nucleosome-free regions, flanked by positioned nucleosomes at both the ends. With their chromosomes-wide distribution, all tRNA genes have a different chromatin context. A single nucleosome dynamics controls the accessibility of the genes for transcription. This dynamics operates under the influence of several chromatin modifiers in a gene-specific manner, giving the scope for differential regulation of even the isogenes within a tRNA gene family. The chromatin structure around the pol III-transcribed genes provides a context conducive for steady-state transcription as well as gene-specific transcriptional regulation upon signaling from the environmental cues. 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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Affiliation(s)
- Ashutosh Shukla
- Centre for Cellular and Molecular Biology (Council of Scientific and Industrial Research), Uppal Road, Hyderabad 500007, India
| | - Purnima Bhargava
- Centre for Cellular and Molecular Biology (Council of Scientific and Industrial Research), Uppal Road, Hyderabad 500007, India.
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17
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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: 31] [Impact Index Per Article: 4.4] [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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18
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Van Bortle K, Phanstiel DH, Snyder MP. Topological organization and dynamic regulation of human tRNA genes during macrophage differentiation. Genome Biol 2017; 18:180. [PMID: 28931413 PMCID: PMC5607496 DOI: 10.1186/s13059-017-1310-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 08/25/2017] [Indexed: 12/11/2022] Open
Abstract
Background The human genome is hierarchically organized into local and long-range structures that help shape cell-type-specific transcription patterns. Transfer RNA (tRNA) genes (tDNAs), which are transcribed by RNA polymerase III (RNAPIII) and encode RNA molecules responsible for translation, are dispersed throughout the genome and, in many cases, linearly organized into genomic clusters with other tDNAs. Whether the location and three-dimensional organization of tDNAs contribute to the activity of these genes has remained difficult to address, due in part to unique challenges related to tRNA sequencing. We therefore devised integrated tDNA expression profiling, a method that combines RNAPIII mapping with biotin-capture of nascent tRNAs. We apply this method to the study of dynamic tRNA gene regulation during macrophage development and further integrate these data with high-resolution maps of 3D chromatin structure. Results Integrated tDNA expression profiling reveals domain-level and loop-based organization of tRNA gene transcription during cellular differentiation. tRNA genes connected by DNA loops, which are proximal to CTCF binding sites and expressed at elevated levels compared to non-loop tDNAs, change coordinately with tDNAs and protein-coding genes at distal ends of interactions mapped by in situ Hi-C. We find that downregulated tRNA genes are specifically marked by enhanced promoter-proximal binding of MAF1, a transcriptional repressor of RNAPIII activity, altogether revealing multiple levels of tDNA regulation during cellular differentiation. Conclusions We present evidence of both local and coordinated long-range regulation of human tDNA expression, suggesting the location and organization of tRNA genes contribute to dynamic tDNA activity during macrophage development. Electronic supplementary material The online version of this article (doi:10.1186/s13059-017-1310-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kevin Van Bortle
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Douglas H Phanstiel
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC, 27599, USA.,Thurston Arthritis Research Center and Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Michael P Snyder
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA.
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19
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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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20
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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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21
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Sin O, de Jong T, Mata-Cabana A, Kudron M, Zaini MA, Aprile FA, Seinstra RI, Stroo E, Prins RW, Martineau CN, Wang HH, Hogewerf W, Steinhof A, Wanker EE, Vendruscolo M, Calkhoven CF, Reinke V, Guryev V, Nollen EAA. Identification of an RNA Polymerase III Regulator Linked to Disease-Associated Protein Aggregation. Mol Cell 2017; 65:1096-1108.e6. [PMID: 28306505 PMCID: PMC5364375 DOI: 10.1016/j.molcel.2017.02.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 01/05/2017] [Accepted: 02/22/2017] [Indexed: 11/24/2022]
Abstract
Protein aggregation is associated with age-related neurodegenerative disorders, such as Alzheimer's and polyglutamine diseases. As a causal relationship between protein aggregation and neurodegeneration remains elusive, understanding the cellular mechanisms regulating protein aggregation will help develop future treatments. To identify such mechanisms, we conducted a forward genetic screen in a C. elegans model of polyglutamine aggregation and identified the protein MOAG-2/LIR-3 as a driver of protein aggregation. In the absence of polyglutamine, MOAG-2/LIR-3 regulates the RNA polymerase III-associated transcription of small non-coding RNAs. This regulation is lost in the presence of polyglutamine, which mislocalizes MOAG-2/LIR-3 from the nucleus to the cytosol. We then show biochemically that MOAG-2/LIR-3 can also catalyze the aggregation of polyglutamine-expanded huntingtin. These results suggest that polyglutamine can induce an aggregation-promoting activity of MOAG-2/LIR-3 in the cytosol. The concept that certain aggregation-prone proteins can convert other endogenous proteins into drivers of aggregation and toxicity adds to the understanding of how cellular homeostasis can be deteriorated in protein misfolding diseases.
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Affiliation(s)
- Olga Sin
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands; Graduate Program in Areas of Basic and Applied Biology, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Tristan de Jong
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands
| | - Alejandro Mata-Cabana
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands
| | - Michelle Kudron
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Mohamad Amr Zaini
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands
| | | | - Renée I Seinstra
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands
| | - Esther Stroo
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands
| | - Roméo Willinge Prins
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands
| | - Céline N Martineau
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands
| | - Hai Hui Wang
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands
| | - Wytse Hogewerf
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands
| | - Anne Steinhof
- Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Erich E Wanker
- Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | | | - Cornelis F Calkhoven
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands
| | - Valerie Reinke
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Victor Guryev
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands.
| | - Ellen A A Nollen
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, 9700 AD Groningen, the Netherlands.
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22
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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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23
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Khattar E, Kumar P, Liu CY, Akıncılar SC, Raju A, Lakshmanan M, Maury JJP, Qiang Y, Li S, Tan EY, Hui KM, Shi M, Loh YH, Tergaonkar V. Telomerase reverse transcriptase promotes cancer cell proliferation by augmenting tRNA expression. J Clin Invest 2016; 126:4045-4060. [PMID: 27643433 DOI: 10.1172/jci86042] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 08/11/2016] [Indexed: 12/13/2022] Open
Abstract
Transcriptional reactivation of telomerase reverse transcriptase (TERT) reconstitutes telomerase activity in the majority of human cancers. Here, we found that ectopic TERT expression increases cell proliferation, while acute reductions in TERT levels lead to a dramatic loss of proliferation without any change in telomere length, suggesting that the effects of TERT could be telomere independent. We observed that TERT determines the growth rate of cancer cells by directly regulating global protein synthesis independently of its catalytic activity. Genome-wide TERT binding across 5 cancer cell lines and 2 embryonic stem cell lines revealed that endogenous TERT, driven by mutant promoters or oncogenes, directly associates with the RNA polymerase III (pol III) subunit RPC32 and enhances its recruitment to chromatin, resulting in increased RNA pol III occupancy and tRNA expression in cancers. TERT-deficient mice displayed marked delays in polyomavirus middle T oncogene-induced (PyMT-induced) mammary tumorigenesis, increased survival, and reductions in tRNA levels. Ectopic expression of either RPC32 or TERT restored tRNA levels and proliferation defects in TERT-depleted cells. Finally, we determined that levels of TERT and tRNA correlated in breast and liver cancer samples. Together, these data suggest the existence of a unifying mechanism by which TERT enhances translation in cells to regulate cancer cell proliferation.
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MESH Headings
- Animals
- Cell Line, Tumor
- Cell Proliferation
- Cell Transformation, Neoplastic/metabolism
- Female
- Gene Expression Regulation, Neoplastic
- HEK293 Cells
- Humans
- Mammary Neoplasms, Experimental/enzymology
- Mammary Neoplasms, Experimental/pathology
- Mice, 129 Strain
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, Knockout
- Mice, SCID
- Neoplasm Transplantation
- Promoter Regions, Genetic
- Protein Binding
- Protein Biosynthesis
- Protein Interaction Domains and Motifs
- RNA Polymerase III/metabolism
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Telomerase/physiology
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24
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Varshney D, Vavrova-Anderson J, Oler AJ, Cairns BR, White RJ. Selective repression of SINE transcription by RNA polymerase III. Mob Genet Elements 2015; 5:86-91. [PMID: 26942044 DOI: 10.1080/2159256x.2015.1096997] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/15/2015] [Accepted: 09/15/2015] [Indexed: 10/23/2022] Open
Abstract
A million copies of the Alu short interspersed nuclear element (SINE) are scattered throughout the human genome, providing ∼11% of our total DNA. SINEs spread by retrotransposition, using a transcript generated by RNA polymerase (pol) III from an internal promoter. Levels of these pol III-dependent Alu transcripts are far lower than might be expected from the abundance of the template. This was believed to reflect transcriptional suppression through DNA methylation, denying pol III access to most SINEs through chromatin-mediated effects. Contrary to expectations, our recent study found no evidence that methylation of SINE DNA reduces its occupancy or expression by pol III. However, histone H3 associated with SINEs is prominently methylated on lysine 9, a mark that correlates with transcriptional silencing. The SUV39 methyltransferases that deposit this mark can be found at many SINEs. Furthermore, a selective inhibitor of SUV39 stimulates pol III recruitment to these loci, as well as SINE expression. These data suggest that methylation of histone H3 rather than DNA may mediate repression of SINE transcription by pol III, at least under the conditions we studied.
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Affiliation(s)
- Dhaval Varshney
- Centre for Gene Regulation and Expression; University of Dundee ; Dundee, UK
| | - Jana Vavrova-Anderson
- College of Medical; Veterinary and Life Sciences; University of Glasgow ; Glasgow, UK
| | - Andrew J Oler
- Bioinformatics and Computational Biosciences Branch; Office of Cyber Infrastructure and Computational Biology, National Institute of Allergy and Infectious Diseases; National Institutes of Health ; Bethesda, MD USA
| | - Bradley R Cairns
- Department of Oncological Sciences; Huntsman Cancer Institute; University of Utah School of Medicine; Salt Lake City, UT USA; Howard Hughes Medical Institute; University of Utah School of Medicine; Salt Lake City, UT USA
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Recessive mutations in POLR1C cause a leukodystrophy by impairing biogenesis of RNA polymerase III. Nat Commun 2015; 6:7623. [PMID: 26151409 PMCID: PMC4506509 DOI: 10.1038/ncomms8623] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 05/26/2015] [Indexed: 12/20/2022] Open
Abstract
A small proportion of 4H (Hypomyelination, Hypodontia and Hypogonadotropic Hypogonadism) or RNA polymerase III (POLR3)-related leukodystrophy cases are negative for mutations in the previously identified causative genes POLR3A and POLR3B. Here we report eight of these cases carrying recessive mutations in POLR1C, a gene encoding a shared POLR1 and POLR3 subunit, also mutated in some Treacher Collins syndrome (TCS) cases. Using shotgun proteomics and ChIP sequencing, we demonstrate that leukodystrophy-causative mutations, but not TCS mutations, in POLR1C impair assembly and nuclear import of POLR3, but not POLR1, leading to decreased binding to POLR3 target genes. This study is the first to show that distinct mutations in a gene coding for a shared subunit of two RNA polymerases lead to selective modification of the enzymes' availability leading to two different clinical conditions and to shed some light on the pathophysiological mechanism of one of the most common hypomyelinating leukodystrophies, POLR3-related leukodystrophy.
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Hajjawi OS. Ribonucleic acid (RNA) biosynthesis in human cancer. Cancer Cell Int 2015; 15:22. [PMID: 25717284 PMCID: PMC4339644 DOI: 10.1186/s12935-015-0167-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/20/2015] [Indexed: 12/28/2022] Open
Abstract
In many respects, the most remarkable chemical substances within the genome of eukaryotic cells are remarkable proteins which are the critical structural and functional units of living cells. The specifications for everything that goes in the cell are natural digital-to-digital decoding process in an archive sequence by deoxyribonucleic acid (DNA) and an articulate construction by ribonucleic acid (RNA). The products of DNA transcription are long polymers of ribonucleotides rather than deoxyribonucleotides and are termed ribonucleic acids. Certain deoxyribonucleotide sequences, or genes, give rise to transfer RNA (tRNA) and other ribosomal RNA (rRNA) when transcribed. The ribonucleotide sequences fold extensively and rRNA is associated with specific proteins to yield the essential cell components, ribosomes. Transcription of other special sequences yields messenger RNAs (mRNAs) that contain ribonucleotide sequences that will be ultimately translated into new types of amino acid sequences of functional cellular protein molecules. This switch to a different variety of cellular molecular sequences is complex, but each sequence of the three ribonucleotides specifies the insertion of one particular amino acid into the polypeptide chain under production. Whilst mRNA is considered the vehicle by which genetic information is transmitted from the genome and allocated in the appropriate cytoplasmic sites for translation into protein via cap-dependent mechanism, the actual translation depends also on the presence of other so-called household and luxury protein molecules. Recent evidence suggests RNA species are required at initiation, because treatment of cells with antibiotics or drugs that inhibit RNA synthesis cause a decrease in protein synthesis. The rRNA is necessary as a structural constituent of the ribosomes upon which translation takes place, whereas tRNA is necessary as an adaptor in amino acid activation and elongation protein chains to ribosomes. In this article, we review malignant tumor, with stem like properties, and recent technical advances into the phenomenon of micro-particles and micro-vesicles containing cell-free nucleic acids that circulate plasma. New areas of research have been opened into screening tumor telomerase progression, prognosis of aptamers targeting cell surface, monitoring the efficacy of anticancer therapies, oncogenic transformation of host cell, and RNA polymerases role in the cell cycle progression and differentiation.
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Affiliation(s)
- Omar S Hajjawi
- Department of Biology, Arab American University, P. O. Box 240, Jenin, Israeli Occupied Territories of Palestine
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