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Sterrett MC, Farchi D, Strassler SE, Boise LH, Fasken MB, Corbett AH. In vivo characterization of the critical interaction between the RNA exosome and the essential RNA helicase Mtr4 in Saccharomyces cerevisiae. G3 (BETHESDA, MD.) 2023; 13:jkad049. [PMID: 36861343 PMCID: PMC10411580 DOI: 10.1093/g3journal/jkad049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/05/2023] [Accepted: 02/10/2023] [Indexed: 03/03/2023]
Abstract
The RNA exosome is a conserved molecular machine that processes/degrades numerous coding and non-coding RNAs. The 10-subunit complex is composed of three S1/KH cap subunits (human EXOSC2/3/1; yeast Rrp4/40/Csl4), a lower ring of six PH-like subunits (human EXOSC4/7/8/9/5/6; yeast Rrp41/42/43/45/46/Mtr3), and a singular 3'-5' exo/endonuclease DIS3/Rrp44. Recently, several disease-linked missense mutations have been identified in structural cap and core RNA exosome genes. In this study, we characterize a rare multiple myeloma patient missense mutation that was identified in the cap subunit gene EXOSC2. This missense mutation results in a single amino acid substitution, p.Met40Thr, in a highly conserved domain of EXOSC2. Structural studies suggest that this Met40 residue makes direct contact with the essential RNA helicase, MTR4, and may help stabilize the critical interaction between the RNA exosome complex and this cofactor. To assess this interaction in vivo, we utilized the Saccharomyces cerevisiae system and modeled the EXOSC2 patient mutation into the orthologous yeast gene RRP4, generating the variant rrp4-M68T. The rrp4-M68T cells show accumulation of certain RNA exosome target RNAs and show sensitivity to drugs that impact RNA processing. We also identified robust negative genetic interactions between rrp4-M68T and specific mtr4 mutants. A complementary biochemical approach revealed that Rrp4 M68T shows decreased interaction with Mtr4, consistent with these genetic results. This study suggests that the EXOSC2 mutation identified in a multiple myeloma patient impacts the function of the RNA exosome and provides functional insight into a critical interface between the RNA exosome and Mtr4.
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Affiliation(s)
- Maria C Sterrett
- Department of Biology, Emory University, Atlanta, GA 30322, USA
- Biochemistry, Cell, and Developmental Biology Graduate Program, Emory University, Atlanta, GA 30322, USA
| | - Daniela Farchi
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Sarah E Strassler
- Biochemistry, Cell, and Developmental Biology Graduate Program, Emory University, Atlanta, GA 30322, USA
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Lawrence H Boise
- Department of Hematology and Medical Oncology, School of Medicine, Emory University, Atlanta, GA 30322, USA
- Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA
| | - Milo B Fasken
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, GA 30322, USA
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2
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The methyl phosphate capping enzyme Bmc1/Bin3 is a stable component of the fission yeast telomerase holoenzyme. Nat Commun 2022; 13:1277. [PMID: 35277511 PMCID: PMC8917221 DOI: 10.1038/s41467-022-28985-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 02/11/2022] [Indexed: 12/13/2022] Open
Abstract
The telomerase holoenzyme is critical for maintaining eukaryotic genome integrity. In addition to a reverse transcriptase and an RNA template, telomerase contains additional proteins that protect the telomerase RNA and promote holoenzyme assembly. Here we report that the methyl phosphate capping enzyme (MePCE) Bmc1/Bin3 is a stable component of the S. pombe telomerase holoenzyme. Bmc1 associates with the telomerase holoenzyme and U6 snRNA through an interaction with the recently described LARP7 family member Pof8, and we demonstrate that these two factors are evolutionarily linked in fungi. Our data suggest that the association of Bmc1 with telomerase is independent of its methyltransferase activity, but rather that Bmc1 functions in telomerase holoenzyme assembly by promoting TER1 accumulation and Pof8 recruitment to TER1. Taken together, this work yields new insight into the composition, assembly, and regulation of the telomerase holoenzyme in fission yeast as well as the breadth of its evolutionary conservation.
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A putative cap binding protein and the methyl phosphate capping enzyme Bin3/MePCE function in telomerase biogenesis. Nat Commun 2022; 13:1067. [PMID: 35217638 PMCID: PMC8881624 DOI: 10.1038/s41467-022-28545-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 01/13/2022] [Indexed: 01/29/2023] Open
Abstract
Telomerase reverse transcriptase (TERT) and the noncoding telomerase RNA (TR) subunit constitute the core of telomerase. Additional subunits are required for ribonucleoprotein complex assembly and in some cases remain stably associated with the active holoenzyme. Pof8, a member of the LARP7 protein family is such a constitutive component of telomerase in fission yeast. Using affinity purification of Pof8, we have identified two previously uncharacterized proteins that form a complex with Pof8 and participate in telomerase biogenesis. Both proteins participate in ribonucleoprotein complex assembly and are required for wildtype telomerase activity and telomere length maintenance. One factor we named Thc1 (Telomerase Holoenzyme Component 1) shares structural similarity with the nuclear cap binding complex and the poly-adenosine ribonuclease (PARN), the other is the ortholog of the methyl phosphate capping enzyme (Bin3/MePCE) in metazoans and was named Bmc1 (Bin3/MePCE 1) to reflect its evolutionary roots. Thc1 and Bmc1 function together with Pof8 in recognizing correctly folded telomerase RNA and promoting the recruitment of the Lsm2-8 complex and the catalytic subunit to assemble functional telomerase. Most eukaryotes maintain telomeres using a specialized reverse transcriptase. Here the authors report that Thc1 (Telomerase Holoenzyme Component 1) and Bmc1 (Bin3/MePCE 1) form a complex with Pof8, a constitutive member of telomerase in fission yeast.
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Birot A, Kus K, Priest E, Al Alwash A, Castello A, Mohammed S, Vasiljeva L, Kilchert C. RNA-binding protein Mub1 and the nuclear RNA exosome act to fine-tune environmental stress response. Life Sci Alliance 2021; 5:5/2/e202101111. [PMID: 34848435 PMCID: PMC8645331 DOI: 10.26508/lsa.202101111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 11/12/2021] [Accepted: 11/12/2021] [Indexed: 11/24/2022] Open
Abstract
Comparative RNA interactome capture identifies potential regulators of RNA metabolism in fission yeast and reveals RNA exosome–dependent buffering of stress-responsive gene expression networks. The nuclear RNA exosome plays a key role in controlling the levels of multiple protein-coding and non-coding RNAs. Recruitment of the exosome to specific RNA substrates is mediated by RNA-binding co-factors. The transient interaction between co-factors and the exosome as well as the rapid decay of RNA substrates make identification of exosome co-factors challenging. Here, we use comparative poly(A)+ RNA interactome capture in fission yeast expressing three different mutants of the exosome to identify proteins that interact with poly(A)+ RNA in an exosome-dependent manner. Our analyses identify multiple RNA-binding proteins whose association with RNA is altered in exosome mutants, including the zinc-finger protein Mub1. Mub1 is required to maintain the levels of a subset of exosome RNA substrates including mRNAs encoding for stress-responsive proteins. Removal of the zinc-finger domain leads to loss of RNA suppression under non-stressed conditions, altered expression of heat shock genes in response to stress, and reduced growth at elevated temperature. These findings highlight the importance of exosome-dependent mRNA degradation in buffering gene expression networks to mediate cellular adaptation to stress.
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Affiliation(s)
- Adrien Birot
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Krzysztof Kus
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Emily Priest
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Ahmad Al Alwash
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Alfredo Castello
- Department of Biochemistry, University of Oxford, Oxford, UK.,MRC-University of Glasgow Centre for Virus Research, Glasgow, UK
| | - Shabaz Mohammed
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Lidia Vasiljeva
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Cornelia Kilchert
- Institute of Biochemistry, Justus-Liebig University Giessen, Giessen, Germany
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5
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Hirsch AG, Becker D, Lamping JP, Krebber H. Unraveling the stepwise maturation of the yeast telomerase including a Cse1 and Mtr10 mediated quality control checkpoint. Sci Rep 2021; 11:22174. [PMID: 34773052 PMCID: PMC8590012 DOI: 10.1038/s41598-021-01599-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 10/29/2021] [Indexed: 01/17/2023] Open
Abstract
Telomerases elongate the ends of chromosomes required for cell immortality through their reverse transcriptase activity. By using the model organism Saccharomyces cerevisiae we defined the order in which the holoenzyme matures. First, a longer precursor of the telomerase RNA, TLC1 is transcribed and exported into the cytoplasm, where it associates with the protecting Sm-ring, the Est and the Pop proteins. This partly matured telomerase is re-imported into the nucleus via Mtr10 and a novel TLC1-import factor, the karyopherin Cse1. Remarkably, while mutations in all known transport factors result in short telomere ends, mutation in CSE1 leads to the amplification of Y′ elements in the terminal chromosome regions and thus elongated telomere ends. Cse1 does not only support TLC1 import, but also the Sm-ring stabilization on the RNA enableling Mtr10 contact and nuclear import. Thus, Sm-ring formation and import factor contact resembles a quality control step in the maturation process of the telomerase. The re-imported immature TLC1 is finally trimmed into the 1158 nucleotides long mature form via the nuclear exosome. TMG-capping of TLC1 finalizes maturation, leading to mature telomerase.
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Affiliation(s)
- Anna Greta Hirsch
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie Und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen, Germany
| | - Daniel Becker
- Philipps-Universität Marburg, Klinik für Dermatologie Und Allergologie, Baldingerstraße, 35043, Marburg, Germany
| | - Jan-Philipp Lamping
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie Und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen, Germany
| | - Heike Krebber
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie Und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen, Germany.
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6
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Sterrett MC, Enyenihi L, Leung SW, Hess L, Strassler SE, Farchi D, Lee RS, Withers ES, Kremsky I, Baker RE, Basrai MA, van Hoof A, Fasken MB, Corbett AH. A budding yeast model for human disease mutations in the EXOSC2 cap subunit of the RNA exosome complex. RNA (NEW YORK, N.Y.) 2021; 27:1046-1067. [PMID: 34162742 PMCID: PMC8370739 DOI: 10.1261/rna.078618.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 06/11/2021] [Indexed: 06/13/2023]
Abstract
RNA exosomopathies, a growing family of diseases, are linked to missense mutations in genes encoding structural subunits of the evolutionarily conserved, 10-subunit exoribonuclease complex, the RNA exosome. This complex consists of a three-subunit cap, a six-subunit, barrel-shaped core, and a catalytic base subunit. While a number of mutations in RNA exosome genes cause pontocerebellar hypoplasia, mutations in the cap subunit gene EXOSC2 cause an apparently distinct clinical presentation that has been defined as a novel syndrome SHRF (short stature, hearing loss, retinitis pigmentosa, and distinctive facies). We generated the first in vivo model of the SHRF pathogenic amino acid substitutions using budding yeast by modeling pathogenic EXOSC2 missense mutations (p.Gly30Val and p.Gly198Asp) in the orthologous S. cerevisiae gene RRP4 The resulting rrp4 mutant cells show defects in cell growth and RNA exosome function. Consistent with altered RNA exosome function, we detect significant transcriptomic changes in both coding and noncoding RNAs in rrp4-G226D cells that model EXOSC2 p.Gly198Asp, suggesting defects in nuclear surveillance. Biochemical and genetic analyses suggest that the Rrp4 G226D variant subunit shows impaired interactions with key RNA exosome cofactors that modulate the function of the complex. These results provide the first in vivo evidence that pathogenic missense mutations present in EXOSC2 impair the function of the RNA exosome. This study also sets the stage to compare exosomopathy models to understand how defects in RNA exosome function underlie distinct pathologies.
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Affiliation(s)
- Maria C Sterrett
- Biochemistry, Cell and Developmental Biology Graduate Program, Emory University, Atlanta, Georgia 30322, USA
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
| | - Liz Enyenihi
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
| | - Sara W Leung
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
| | - Laurie Hess
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
| | - Sarah E Strassler
- Biochemistry, Cell and Developmental Biology Graduate Program, Emory University, Atlanta, Georgia 30322, USA
- Department of Biochemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Daniela Farchi
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
| | - Richard S Lee
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
| | - Elise S Withers
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
| | - Isaac Kremsky
- Loma Linda University School of Medicine, Loma Linda, California 92350, USA
| | - Richard E Baker
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Munira A Basrai
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Milo B Fasken
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
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7
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Slavotinek A, Misceo D, Htun S, Mathisen L, Frengen E, Foreman M, Hurtig JE, Enyenihi L, Sterrett MC, Leung SW, Schneidman-Duhovny D, Estrada-Veras J, Duncan JL, Haaxma CA, Kamsteeg EJ, Xia V, Beleford D, Si Y, Douglas G, Treidene HE, van Hoof A, Fasken MB, Corbett AH. Biallelic variants in the RNA exosome gene EXOSC5 are associated with developmental delays, short stature, cerebellar hypoplasia and motor weakness. Hum Mol Genet 2021; 29:2218-2239. [PMID: 32504085 DOI: 10.1093/hmg/ddaa108] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/10/2020] [Accepted: 05/28/2020] [Indexed: 12/15/2022] Open
Abstract
The RNA exosome is an essential ribonuclease complex required for processing and/or degradation of both coding and non-coding RNAs. We identified five patients with biallelic variants in EXOSC5, which encodes a structural subunit of the RNA exosome. The clinical features of these patients include failure to thrive, short stature, feeding difficulties, developmental delays that affect motor skills, hypotonia and esotropia. Brain MRI revealed cerebellar hypoplasia and ventriculomegaly. While we ascertained five patients, three patients with distinct variants of EXOSC5 were studied in detail. The first patient had a deletion involving exons 5-6 of EXOSC5 and a missense variant, p.Thr114Ile, that were inherited in trans, the second patient was homozygous for p.Leu206His and the third patient had paternal isodisomy for chromosome 19 and was homozygous for p.Met148Thr. The additional two patients ascertained are siblings who had an early frameshift mutation in EXOSC5 and the p.Thr114Ile missense variant that were inherited in trans. We employed three complementary approaches to explore the requirement for EXOSC5 in brain development and assess consequences of pathogenic EXOSC5 variants. Loss of function for exosc5 in zebrafish results in shortened and curved tails/bodies, reduced eye/head size and edema. We modeled pathogenic EXOSC5 variants in both budding yeast and mammalian cells. Some of these variants cause defects in RNA exosome function as well as altered interactions with other RNA exosome subunits. These findings expand the number of genes encoding RNA exosome subunits linked to human disease while also suggesting that disease mechanism varies depending on the specific pathogenic variant.
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Affiliation(s)
- Anne Slavotinek
- Department of Pediatrics, University of California, San Francisco, CA 94143, USA
| | - Doriana Misceo
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo 0450, Norway
| | - Stephanie Htun
- Department of Pediatrics, University of California, San Francisco, CA 94143, USA
| | - Linda Mathisen
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo 0450, Norway
| | - Eirik Frengen
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo 0450, Norway
| | - Michelle Foreman
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
| | - Jennifer E Hurtig
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
| | - Liz Enyenihi
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | | | - Sara W Leung
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Dina Schneidman-Duhovny
- School of Computer Science and Engineering and the Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Juvianee Estrada-Veras
- Department of Pediatrics-Medical Genetics and Metabolism, Uniformed Services University/Walter Reed NMMC Bethesda, MD 20889, USA
| | - Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, CA 94143, USA
| | - Charlotte A Haaxma
- Department of Pediatric Neurology, Amalia Children's Hospital and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen 6500 HB, The Netherlands
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen 6500 HB, The Netherlands
| | - Vivian Xia
- Department of Pediatrics, University of California, San Francisco, CA 94143, USA
| | - Daniah Beleford
- Department of Pediatrics, University of California, San Francisco, CA 94143, USA
| | - Yue Si
- GeneDx Inc., MD 20877, USA
| | | | - Hans Einar Treidene
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo 0450, Norway
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
| | - Milo B Fasken
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, GA 30322, USA
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8
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Abstract
The identity and metabolism of RNAs are often governed by their 5' and 3' ends. Single gene loci produce a variety of transcript isoforms, varying primarily in their RNA 3' end status and consequently facing radically different cellular fates. Knowledge about RNA termini is therefore key to understanding the diverse RNA output from individual transcription units. In addition, the 3' end of a nascent RNA at the catalytic center of RNA polymerase provides a precise and strand-specific measure of the transcription process. Here, we describe a modified RNA 3' end sequencing method, that utilizes the in vivo metabolic labeling of RNA followed by its purification and optional in vitro polyadenylation to provide a comprehensive view of all RNA 3' ends. The strategy offers the advantages of (i) nucleotide resolution mapping of RNA 3' ends, (ii) increased sequencing depth of lowly abundant RNA and (iii) inference of RNA 3' end polyadenylation status. We have used the method to study RNA decay and transcription termination mechanisms with the potential utility to a wider range of biological questions.
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Affiliation(s)
- Guifen Wu
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Manfred Schmid
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark.
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9
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Norppa AJ, Frilander MJ. The integrity of the U12 snRNA 3' stem-loop is necessary for its overall stability. Nucleic Acids Res 2021; 49:2835-2847. [PMID: 33577674 PMCID: PMC7968993 DOI: 10.1093/nar/gkab048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 01/14/2021] [Accepted: 02/07/2021] [Indexed: 12/20/2022] Open
Abstract
Disruption of minor spliceosome functions underlies several genetic diseases with mutations in the minor spliceosome-specific small nuclear RNAs (snRNAs) and proteins. Here, we define the molecular outcome of the U12 snRNA mutation (84C>U) resulting in an early-onset form of cerebellar ataxia. To understand the molecular consequences of the U12 snRNA mutation, we created cell lines harboring the 84C>T mutation in the U12 snRNA gene (RNU12). We show that the 84C>U mutation leads to accelerated decay of the snRNA, resulting in significantly reduced steady-state U12 snRNA levels. Additionally, the mutation leads to accumulation of 3′-truncated forms of U12 snRNA, which have undergone the cytoplasmic steps of snRNP biogenesis. Our data suggests that the 84C>U-mutant snRNA is targeted for decay following reimport into the nucleus, and that the U12 snRNA fragments are decay intermediates that result from the stalling of a 3′-to-5′ exonuclease. Finally, we show that several other single-nucleotide variants in the 3′ stem-loop of U12 snRNA that are segregating in the human population are also highly destabilizing. This suggests that the 3′ stem-loop is important for the overall stability of the U12 snRNA and that additional disease-causing mutations are likely to exist in this region.
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Affiliation(s)
- Antto J Norppa
- Institute of Biotechnology, P.O. Box 56, Viikinkaari 5, University of Helsinki, FI-00014 Helsinki, Finland
| | - Mikko J Frilander
- Institute of Biotechnology, P.O. Box 56, Viikinkaari 5, University of Helsinki, FI-00014 Helsinki, Finland
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10
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Integrator is a genome-wide attenuator of non-productive transcription. Mol Cell 2020; 81:514-529.e6. [PMID: 33385327 DOI: 10.1016/j.molcel.2020.12.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 10/11/2020] [Accepted: 11/20/2020] [Indexed: 12/28/2022]
Abstract
Termination of RNA polymerase II (RNAPII) transcription in metazoans relies largely on the cleavage and polyadenylation (CPA) and integrator (INT) complexes originally found to act at the ends of protein-coding and small nuclear RNA (snRNA) genes, respectively. Here, we monitor CPA- and INT-dependent termination activities genome-wide, including at thousands of previously unannotated transcription units (TUs), producing unstable RNA. We verify the global activity of CPA occurring at pA sites indiscriminately of their positioning relative to the TU promoter. We also identify a global activity of INT, which is largely sequence-independent and restricted to a ~3-kb promoter-proximal region. Our analyses suggest two functions of genome-wide INT activity: it dampens transcriptional output from weak promoters, and it provides quality control of RNAPII complexes that are unfavorably configured for transcriptional elongation. We suggest that the function of INT in stable snRNA production is an exception from its general cellular role, the attenuation of non-productive transcription.
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11
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Fraga de Andrade I, Mehta C, Bresnick EH. Post-transcriptional control of cellular differentiation by the RNA exosome complex. Nucleic Acids Res 2020; 48:11913-11928. [PMID: 33119769 PMCID: PMC7708067 DOI: 10.1093/nar/gkaa883] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/21/2020] [Accepted: 09/30/2020] [Indexed: 12/12/2022] Open
Abstract
Given the complexity of intracellular RNA ensembles and vast phenotypic remodeling intrinsic to cellular differentiation, it is instructive to consider the role of RNA regulatory machinery in controlling differentiation. Dynamic post-transcriptional regulation of protein-coding and non-coding transcripts is vital for establishing and maintaining proteomes that enable or oppose differentiation. By contrast to extensively studied transcriptional mechanisms governing differentiation, many questions remain unanswered regarding the involvement of post-transcriptional mechanisms. Through its catalytic activity to selectively process or degrade RNAs, the RNA exosome complex dictates the levels of RNAs comprising multiple RNA classes, thereby regulating chromatin structure, gene expression and differentiation. Although the RNA exosome would be expected to control diverse biological processes, studies to elucidate its biological functions and how it integrates into, or functions in parallel with, cell type-specific transcriptional mechanisms are in their infancy. Mechanistic analyses have demonstrated that the RNA exosome confers expression of a differentiation regulatory receptor tyrosine kinase, downregulates the telomerase RNA component TERC, confers genomic stability and promotes DNA repair, which have considerable physiological and pathological implications. In this review, we address how a broadly operational RNA regulatory complex interfaces with cell type-specific machinery to control cellular differentiation.
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Affiliation(s)
- Isabela Fraga de Andrade
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, 4009 WIMR, Madison, WI 53705, USA
| | - Charu Mehta
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, 4009 WIMR, Madison, WI 53705, USA
| | - Emery H Bresnick
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, 4009 WIMR, Madison, WI 53705, USA
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12
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Vasianovich Y, Bajon E, Wellinger RJ. Telomerase biogenesis requires a novel Mex67 function and a cytoplasmic association with the Sm 7 complex. eLife 2020; 9:60000. [PMID: 33095156 PMCID: PMC7644208 DOI: 10.7554/elife.60000] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 10/22/2020] [Indexed: 12/15/2022] Open
Abstract
The templating RNA is the core of the telomerase reverse transcriptase. In Saccharomyces cerevisiae, the complex life cycle and maturation of telomerase includes a cytoplasmic stage. However, timing and reason for this cytoplasmic passage are poorly understood. Here, we use inducible RNA tagging experiments to show that immediately after transcription, newly synthesized telomerase RNAs undergo one round of nucleo-cytoplasmic shuttling. Their export depends entirely on Crm1/Xpo1, whereas re-import is mediated by Kap122 plus redundant, kinetically less efficient import pathways. Strikingly, Mex67 is essential to stabilize newly transcribed RNA before Xpo1-mediated nuclear export. The results further show that the Sm7 complex associates with and stabilizes the telomerase RNA in the cytoplasm and promotes its nuclear re-import. Remarkably, after this cytoplasmic passage, the nuclear stability of telomerase RNA no longer depends on Mex67. These results underscore the utility of inducible RNA tagging and challenge current models of telomerase maturation.
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Affiliation(s)
- Yulia Vasianovich
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Canada
| | - Emmanuel Bajon
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Canada
| | - Raymund J Wellinger
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Canada
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Hass EP, Zappulla DC. Repositioning the Sm-Binding Site in Saccharomyces cerevisiae Telomerase RNA Reveals RNP Organizational Flexibility and Sm-Directed 3'-End Formation. Noncoding RNA 2020; 6:ncrna6010009. [PMID: 32121425 PMCID: PMC7151599 DOI: 10.3390/ncrna6010009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 01/10/2023] Open
Abstract
Telomerase RNA contains a template for synthesizing telomeric DNA and has been proposed to act as a flexible scaffold for holoenzyme protein subunits in the RNP. In Saccharomyces cerevisiae, the telomerase RNA, TLC1, is bound by the Sm7 protein complex, which is required for stabilization of the predominant, non-polyadenylated (poly(A)–) TLC1 isoform. However, it remains unclear (1) whether Sm7 retains this function when its binding site is repositioned within TLC1, as has been shown for other TLC1-binding telomerase subunits, and (2) how Sm7 stabilizes poly(A)– TLC1. Here, we first show that Sm7 can stabilize poly(A)– TLC1 even when its binding site is repositioned via circular permutation to several different positions within TLC1, further supporting the conclusion that the telomerase holoenzyme is organizationally flexible. Next, we show that when an Sm site is inserted 5′ of its native position and the native site is mutated, Sm7 stabilizes shorter forms of poly(A)– TLC1 in a manner corresponding to how far upstream the new site was inserted, providing strong evidence that Sm7 binding to TLC1 controls where the mature poly(A)– 3′ is formed by directing a 3′-to-5′ processing mechanism. In summary, our results show that Sm7 and the 3′ end of yeast telomerase RNA comprise an organizationally flexible module within the telomerase RNP and provide insights into the mechanistic role of Sm7 in telomerase RNA biogenesis.
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Affiliation(s)
- Evan P. Hass
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA;
| | - David C. Zappulla
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA;
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
- Correspondence: ; Tel.:+1-(610)-758-5088
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14
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Gable DL, Gaysinskaya V, Atik CC, Talbot CC, Kang B, Stanley SE, Pugh EW, Amat-Codina N, Schenk KM, Arcasoy MO, Brayton C, Florea L, Armanios M. ZCCHC8, the nuclear exosome targeting component, is mutated in familial pulmonary fibrosis and is required for telomerase RNA maturation. Genes Dev 2019; 33:1381-1396. [PMID: 31488579 PMCID: PMC6771387 DOI: 10.1101/gad.326785.119] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 08/15/2019] [Indexed: 11/25/2022]
Abstract
In this study, Gable et al. follow a family with early onset pulmonary fibrosis and report the discovery of a new genetic cause of pulmonary fibrosis. They use multidimensional analysis methods, involving molecular studies, mouse model, and transcriptome-wide studies to show that heterozygous loss-of-function of the exosomal targeting protein ZCCHC8 to identify a novel cause of telomerase insufficiency in human disease. Short telomere syndromes manifest as familial idiopathic pulmonary fibrosis; they are the most common premature aging disorders. We used genome-wide linkage to identify heterozygous loss of function of ZCCHC8, a zinc-knuckle containing protein, as a cause of autosomal dominant pulmonary fibrosis. ZCCHC8 associated with TR and was required for telomerase function. In ZCCHC8 knockout cells and in mutation carriers, genomically extended telomerase RNA (TR) accumulated at the expense of mature TR, consistent with a role for ZCCHC8 in mediating TR 3′ end targeting to the nuclear RNA exosome. We generated Zcchc8-null mice and found that heterozygotes, similar to human mutation carriers, had TR insufficiency but an otherwise preserved transcriptome. In contrast, Zcchc8−/− mice developed progressive and fatal neurodevelopmental pathology with features of a ciliopathy. The Zcchc8−/− brain transcriptome was highly dysregulated, showing accumulation and 3′ end misprocessing of other low-abundance RNAs, including those encoding cilia components as well as the intronless replication-dependent histones. Our data identify a novel cause of human short telomere syndromes-familial pulmonary fibrosis and uncover nuclear exosome targeting as an essential 3′ end maturation mechanism that vertebrate TR shares with replication-dependent histones.
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Affiliation(s)
- Dustin L Gable
- Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.,Telomere Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | - Valeriya Gaysinskaya
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.,Telomere Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | - Christine C Atik
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.,Telomere Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | - C Conover Talbot
- Institute for Basic Biomedical Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Byunghak Kang
- Department of Comparative and Molecular Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | - Susan E Stanley
- Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.,Telomere Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | - Elizabeth W Pugh
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | - Nuria Amat-Codina
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.,Telomere Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | - Kara M Schenk
- Osler Medical Housestaff Training Program, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Murat O Arcasoy
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina 27708, USA
| | - Cory Brayton
- Department of Comparative and Molecular Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | - Liliana Florea
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | - Mary Armanios
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.,Telomere Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.,Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.,Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
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15
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Becker D, Hirsch AG, Bender L, Lingner T, Salinas G, Krebber H. Nuclear Pre-snRNA Export Is an Essential Quality Assurance Mechanism for Functional Spliceosomes. Cell Rep 2019; 27:3199-3214.e3. [PMID: 31189105 DOI: 10.1016/j.celrep.2019.05.031] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 04/03/2019] [Accepted: 05/09/2019] [Indexed: 02/05/2023] Open
Abstract
Removal of introns from pre-mRNAs is an essential step in eukaryotic gene expression, mediated by spliceosomes that contain snRNAs as key components. Although snRNAs are transcribed in the nucleus and function in the same compartment, all except U6 shuttle to the cytoplasm. Surprisingly, the physiological relevance for shuttling is unclear, in particular because the snRNAs in Saccharomyces cerevisiae were reported to remain nuclear. Here, we show that all yeast pre-snRNAs including U6 undergo a stepwise maturation process after nuclear export by Mex67 and Xpo1. Sm- and Lsm-ring attachment occurs in the cytoplasm and is important for the snRNA re-import, mediated by Cse1 and Mtr10. Finally, nuclear pre-snRNA cleavage and trimethylation of the 5'-cap finalizes shuttling. Importantly, preventing pre-snRNAs from being exported or processed results in faulty spliceosome assembly and subsequent genome-wide splicing defects. Thus, pre-snRNA export is obligatory for functional splicing and resembles an essential evolutionarily conserved quality assurance step.
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Affiliation(s)
- Daniel Becker
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen, Germany
| | - Anna Greta Hirsch
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen, Germany
| | - Lysann Bender
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen, Germany
| | - Thomas Lingner
- Transkriptomanalyselabor, Institut für Entwicklungsbiochemie, Georg-August Universität Göttingen, Göttingen, Germany
| | - Gabriela Salinas
- Transkriptomanalyselabor, Institut für Entwicklungsbiochemie, Georg-August Universität Göttingen, Göttingen, Germany
| | - Heike Krebber
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen, Germany.
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16
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Peck SA, Hughes KD, Victorino JF, Mosley AL. Writing a wrong: Coupled RNA polymerase II transcription and RNA quality control. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1529. [PMID: 30848101 PMCID: PMC6570551 DOI: 10.1002/wrna.1529] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 12/27/2018] [Accepted: 02/07/2019] [Indexed: 12/20/2022]
Abstract
Processing and maturation of precursor RNA species is coupled to RNA polymerase II transcription. Co-transcriptional RNA processing helps to ensure efficient and proper capping, splicing, and 3' end processing of different RNA species to help ensure quality control of the transcriptome. Many improperly processed transcripts are not exported from the nucleus, are restricted to the site of transcription, and are in some cases degraded, which helps to limit any possibility of aberrant RNA causing harm to cellular health. These critical quality control pathways are regulated by the highly dynamic protein-protein interaction network at the site of transcription. Recent work has further revealed the extent to which the processes of transcription and RNA processing and quality control are integrated, and how critically their coupling relies upon the dynamic protein interactions that take place co-transcriptionally. This review focuses specifically on the intricate balance between 3' end processing and RNA decay during transcription termination. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Processing > 3' End Processing RNA Processing > Splicing Mechanisms RNA Processing > Capping and 5' End Modifications.
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Affiliation(s)
- Sarah A Peck
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Katlyn D Hughes
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jose F Victorino
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Amber L Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
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17
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Schmid M, Jensen TH. The Nuclear RNA Exosome and Its Cofactors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:113-132. [PMID: 31811632 DOI: 10.1007/978-3-030-31434-7_4] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The RNA exosome is a highly conserved ribonuclease endowed with 3'-5' exonuclease and endonuclease activities. The multisubunit complex resides in both the nucleus and the cytoplasm, with varying compositions and activities between the two compartments. While the cytoplasmic exosome functions mostly in mRNA quality control pathways, the nuclear RNA exosome partakes in the 3'-end processing and complete decay of a wide variety of substrates, including virtually all types of noncoding (nc) RNAs. To handle these diverse tasks, the nuclear exosome engages with dedicated cofactors, some of which serve as activators by stimulating decay through oligoA addition and/or RNA helicase activities or, as adaptors, by recruiting RNA substrates through their RNA-binding capacities. Most nuclear exosome cofactors contain the essential RNA helicase Mtr4 (MTR4 in humans). However, apart from Mtr4, nuclear exosome cofactors have undergone significant evolutionary divergence. Here, we summarize biochemical and functional knowledge about the nuclear exosome and exemplify its cofactor variety by discussing the best understood model organisms-the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe, and human cells.
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Affiliation(s)
- Manfred Schmid
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark.
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18
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Garcia-Vaquero ML, Gama-Carvalho M, Rivas JDL, Pinto FR. Searching the overlap between network modules with specific betweeness (S2B) and its application to cross-disease analysis. Sci Rep 2018; 8:11555. [PMID: 30068933 PMCID: PMC6070533 DOI: 10.1038/s41598-018-29990-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 07/23/2018] [Indexed: 12/14/2022] Open
Abstract
Discovering disease-associated genes (DG) is strategic for understanding pathological mechanisms. DGs form modules in protein interaction networks and diseases with common phenotypes share more DGs or have more closely interacting DGs. This prompted the development of Specific Betweenness (S2B) to find genes associated with two related diseases. S2B prioritizes genes frequently and specifically present in shortest paths linking two disease modules. Top S2B scores identified genes in the overlap of artificial network modules more than 80% of the times, even with incomplete or noisy knowledge. Applied to Amyotrophic Lateral Sclerosis and Spinal Muscular Atrophy, S2B candidates were enriched in biological processes previously associated with motor neuron degeneration. Some S2B candidates closely interacted in network cliques, suggesting common molecular mechanisms for the two diseases. S2B is a valuable tool for DG prediction, bringing new insights into pathological mechanisms. More generally, S2B can be applied to infer the overlap between other types of network modules, such as functional modules or context-specific subnetworks. An R package implementing S2B is publicly available at https://github.com/frpinto/S2B .
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Affiliation(s)
- Marina L Garcia-Vaquero
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8 bdg, 1749-016, Lisboa, Portugal
| | - Margarida Gama-Carvalho
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8 bdg, 1749-016, Lisboa, Portugal
| | - Javier De Las Rivas
- Cancer Research Center (CiC-IBMCC, CSIC/USAL/IBSAL), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad de Salamanca (USAL), Salamanca, Spain
| | - Francisco R Pinto
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8 bdg, 1749-016, Lisboa, Portugal.
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19
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Skamagki M, Zhang C, Ross CA, Ananthanarayanan A, Liu Z, Mu Q, Basu U, Wang J, Zhao R, Li H, Kim K. RNA Exosome Complex-Mediated Control of Redox Status in Pluripotent Stem Cells. Stem Cell Reports 2018; 9:1053-1061. [PMID: 29020613 PMCID: PMC5639470 DOI: 10.1016/j.stemcr.2017.08.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/29/2017] [Accepted: 08/30/2017] [Indexed: 12/24/2022] Open
Abstract
The RNA exosome complex targets AU-rich element (ARE)-containing mRNAs in eukaryotic cells. We identified a transcription factor, ZSCAN10, which binds to the promoters of multiple RNA exosome complex subunits in pluripotent stem cells to maintain subunit gene expression. We discovered that induced pluripotent stem cell clones generated from aged tissue donors (A-iPSC) show poor expression of ZSCAN10, leading to poor RNA exosome complex expression, and a subsequent elevation in ARE-containing RNAs, including glutathione peroxidase 2 (Gpx2). Excess GPX2 leads to excess glutathione-mediated reactive oxygen species scavenging activity that blunts the DNA damage response and apoptosis. Expression of ZSCAN10 in A-iPSC recovers RNA exosome gene expression, the DNA damage response, and apoptosis. These findings reveal the central role of ZSCAN10 and the RNA exosome complex in maintaining pluripotent stem cell redox status to support a normal DNA damage response.
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Affiliation(s)
- Maria Skamagki
- Cancer Biology and Genetics Program, The Center for Cell Engineering, The Center for Stem Cell Biology, Memorial Sloan-Kettering Cancer Center, Sloan-Kettering Institute for Cancer Research, New York, NY 10065, USA; Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Cheng Zhang
- Department of Molecular Pharmacology & Experimental Therapeutics, Center for Individualized Medicine, Mayo Clinic College of Medicine, Rochester, MN 55902, USA
| | - Christian A Ross
- Department of Molecular Pharmacology & Experimental Therapeutics, Center for Individualized Medicine, Mayo Clinic College of Medicine, Rochester, MN 55902, USA
| | - Aparna Ananthanarayanan
- Cancer Biology and Genetics Program, The Center for Cell Engineering, The Center for Stem Cell Biology, Memorial Sloan-Kettering Cancer Center, Sloan-Kettering Institute for Cancer Research, New York, NY 10065, USA; Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Zhong Liu
- Department of Biochemistry and Molecular Genetics, Stem Cell Institute, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Quanhua Mu
- Divisions of Life Science, Department of Chemical and Biomedical Engineering, School of Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Uttiya Basu
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Jiguang Wang
- Divisions of Life Science, Department of Chemical and Biomedical Engineering, School of Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Rui Zhao
- Department of Biochemistry and Molecular Genetics, Stem Cell Institute, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Hu Li
- Department of Molecular Pharmacology & Experimental Therapeutics, Center for Individualized Medicine, Mayo Clinic College of Medicine, Rochester, MN 55902, USA.
| | - Kitai Kim
- Cancer Biology and Genetics Program, The Center for Cell Engineering, The Center for Stem Cell Biology, Memorial Sloan-Kettering Cancer Center, Sloan-Kettering Institute for Cancer Research, New York, NY 10065, USA; Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York, NY 10065, USA.
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20
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21
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Bresson S, Tollervey D. Surveillance-ready transcription: nuclear RNA decay as a default fate. Open Biol 2018; 8:170270. [PMID: 29563193 PMCID: PMC5881035 DOI: 10.1098/rsob.170270] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/23/2018] [Indexed: 12/21/2022] Open
Abstract
Eukaryotic cells synthesize enormous quantities of RNA from diverse classes, most of which are subject to extensive processing. These processes are inherently error-prone, and cells have evolved robust quality control mechanisms to selectively remove aberrant transcripts. These surveillance pathways monitor all aspects of nuclear RNA biogenesis, and in addition remove nonfunctional transcripts arising from spurious transcription and a host of non-protein-coding RNAs (ncRNAs). Surprisingly, this is largely accomplished with only a handful of RNA decay enzymes. It has, therefore, been unclear how these factors efficiently distinguish between functional RNAs and huge numbers of diverse transcripts that must be degraded. Here we describe how bona fide transcripts are specifically protected, particularly by 5' and 3' modifications. Conversely, a plethora of factors associated with the nascent transcripts all act to recruit the RNA quality control, surveillance and degradation machinery. We conclude that initiating RNAPII is 'surveillance ready', with degradation being a default fate for all transcripts that lack specific protective features. We further postulate that this promiscuity is a key feature that allowed the proliferation of vast numbers of ncRNAs in eukaryotes, including humans.
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Affiliation(s)
- Stefan Bresson
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - David Tollervey
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
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22
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Al-Mayah AHJ, Bright SJ, Bowler DA, Slijepcevic P, Goodwin E, Kadhim MA. Exosome-Mediated Telomere Instability in Human Breast Epithelial Cancer Cells after X Irradiation. Radiat Res 2016; 187:98-106. [PMID: 27959588 DOI: 10.1667/rr14201.1] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In directly irradiating cells, telomere metabolism is altered and similar effects have been observed in nontargeted cells. Exosomes and their cargo play dominant roles in communicating radiation-induced bystander effects with end points related to DNA damage. Here we report novel evidence that exosomes are also responsible for inducing telomere-related bystander effects. Breast epithelial cancer cells were exposed to either 2 Gy X rays, or exposed to irradiated cell conditioned media (ICCM), or exosomes purified from ICCM. Compared to control cells, telomerase activity decreased in the 2 Gy irradiated cells and both bystander samples after one population doubling. At the first population doubling, telomere length was shorter in the 2 Gy irradiated sample but not in the bystander samples. By 24 population doublings telomerase activity recovered to control levels in all samples; however, the 2 Gy irradiated sample continued to demonstrate short telomeres and both bystander samples acquired shorter telomeres. RNase treatment of exosomes prevented the bystander effects on telomerase and telomere length that were observed at 1 population doubling and 24 population doublings, respectively. Thermal denaturation by boiling eliminated the reduction of telomere length in bystander samples, suggesting that the protein fraction of exosomes also contributes to the telomeric effect. RNase treatment plus boiling abrogated all telomere-related effects in directly irradiated and bystander cell populations. These findings suggest that both proteins and RNAs of exosomes can induce alterations in telomeric metabolism, which can instigate genomic instability in epithelial cancer cells after X-ray irradiation.
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Affiliation(s)
- Ammar H J Al-Mayah
- a Genomic Instability Group, Oxford Brookes University, Gipsy Lane Campus, Headington, Oxford OX3 0BP, United Kingdom
| | - Scott J Bright
- a Genomic Instability Group, Oxford Brookes University, Gipsy Lane Campus, Headington, Oxford OX3 0BP, United Kingdom
| | - Debbie A Bowler
- a Genomic Instability Group, Oxford Brookes University, Gipsy Lane Campus, Headington, Oxford OX3 0BP, United Kingdom
| | - Predrag Slijepcevic
- b Department of Life Sciences, College of Health and Life Sciences, Brunel University, London UB8 3PH, United Kingdom
| | - Edwin Goodwin
- c The New Mexico Consortium, Los Alamos, New Mexico 87544
| | - Munira A Kadhim
- a Genomic Instability Group, Oxford Brookes University, Gipsy Lane Campus, Headington, Oxford OX3 0BP, United Kingdom
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23
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The regulation and functions of the nuclear RNA exosome complex. Nat Rev Mol Cell Biol 2016; 17:227-39. [PMID: 26726035 DOI: 10.1038/nrm.2015.15] [Citation(s) in RCA: 269] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The RNA exosome complex is the most versatile RNA-degradation machine in eukaryotes. The exosome has a central role in several aspects of RNA biogenesis, including RNA maturation and surveillance. Moreover, it is emerging as an important player in regulating the expression levels of specific mRNAs in response to environmental cues and during cell differentiation and development. Although the mechanisms by which RNA is targeted to (or escapes from) the exosome are still not fully understood, general principles have begun to emerge, which we discuss in this Review. In addition, we introduce and discuss novel, previously unappreciated functions of the nuclear exosome, including in transcription regulation and in the maintenance of genome stability.
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Rubtsova M, Vasilkova D, Naraykina Y, Dontsova O. Peculiarities of Yeasts and Human Telomerase RNAs Processing. Acta Naturae 2016; 8:14-22. [PMID: 28050263 PMCID: PMC5199203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Telomerase is one of the major components of the telomeres -- linear eukaryotic chromosome ends - maintenance system. Linear chromosomes are shortened during each cell division due to the removal of the primer used for DNA replication. Special repeated telomere sequences at the very ends of linear chromosomes prevent the deletion of genome information caused by primer removal. Telomeres are shortened at each replication round until it becomes critically short and is no longer able to protect the chromosome in somatic cells. At this stage, a cell undergoes a crisis and usually dies. Rare cases result in telomerase activation, and the cell gains unlimited proliferative capacity. Special types of cells, such as stem, germ, embryonic cells and cells from tissues with a high proliferative potential, maintain their telomerase activity indefinitely. The telomerase is inactive in the majority of somatic cells. Telomerase activity in vitro requires two key components: telomerase reverse transcriptase and telomerase RNA. In cancer cells, telomerase reactivates due to the expression of the reverse transcriptase gene. Telomerase RNA expresses constitutively in the majority of human cells. This fact suggests that there are alternative functions to telomerase RNA that are unknown at the moment. In this manuscript, we review the biogenesis of yeasts and human telomerase RNAs thanks to breakthroughs achieved in research on telomerase RNA processing by different yeasts species and humans in the last several years.
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Affiliation(s)
- M.P. Rubtsova
- Lomonosov Moscow State University, Chemistry Department, Leninskie gory, 1, bld. 3, Moscow, 119991 , Russia ,Lomonosov Moscow State University, Belozersky Institute of physico-chemical biology, Leninskie gory, 1, bld. 40, Moscow, 119991, Russia
| | - D.P. Vasilkova
- Lomonosov Moscow State University, Chemistry Department, Leninskie gory, 1, bld. 3, Moscow, 119991 , Russia
| | - Yu.V. Naraykina
- Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, bld. 3, Moscow, 143026 , Russia
| | - O.A. Dontsova
- Lomonosov Moscow State University, Chemistry Department, Leninskie gory, 1, bld. 3, Moscow, 119991 , Russia ,Lomonosov Moscow State University, Belozersky Institute of physico-chemical biology, Leninskie gory, 1, bld. 40, Moscow, 119991, Russia ,Lomonosov Moscow State University, Faculty of bioengineering and bioinformatics, Leninskie gory, 1, bld. 73, Moscow, 119991, Russia
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25
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Tseng CK, Wang HF, Burns A, Schroeder M, Gaspari M, Baumann P. Human Telomerase RNA Processing and Quality Control. Cell Rep 2015; 13:2232-43. [DOI: 10.1016/j.celrep.2015.10.075] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 10/02/2015] [Accepted: 10/27/2015] [Indexed: 12/11/2022] Open
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26
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Tudek A, Candelli T, Libri D. Non-coding transcription by RNA polymerase II in yeast: Hasard or nécessité? Biochimie 2015; 117:28-36. [DOI: 10.1016/j.biochi.2015.04.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/27/2015] [Indexed: 12/17/2022]
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Müller JS, Giunta M, Horvath R. Exosomal Protein Deficiencies: How Abnormal RNA Metabolism Results in Childhood-Onset Neurological Diseases. J Neuromuscul Dis 2015; 2:S31-S37. [PMID: 27127732 PMCID: PMC4845884 DOI: 10.3233/jnd-150086] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Defects of RNA metabolism have been increasingly identified in various forms of inherited neurological diseases. Recently, abnormal RNA degradation due to mutations in human exosome subunit genes has been shown to cause complex childhood onset neurological presentations including spinal muscular atrophy, pontocerebellar hypoplasia and myelination deficiencies. This paper summarizes our current knowledge about the exosome in human neurological disease and provides some important insights into potential disease mechanisms.
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Affiliation(s)
- Juliane S. Müller
- Institute of Genetic Medicine, The John Walton Muscular Dystrophy Research Centre, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, UK
| | - Michele Giunta
- Institute of Genetic Medicine, The John Walton Muscular Dystrophy Research Centre, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, UK
| | - Rita Horvath
- Institute of Genetic Medicine, The John Walton Muscular Dystrophy Research Centre, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, UK
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Schmid M, Olszewski P, Pelechano V, Gupta I, Steinmetz LM, Jensen TH. The Nuclear PolyA-Binding Protein Nab2p Is Essential for mRNA Production. Cell Rep 2015; 12:128-139. [PMID: 26119729 DOI: 10.1016/j.celrep.2015.06.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 05/13/2015] [Accepted: 06/01/2015] [Indexed: 10/23/2022] Open
Abstract
Polyadenylation of mRNA is a key step in eukaryotic gene expression. However, despite the major impact of poly(A) tails on mRNA metabolism, the precise roles of poly(A)-binding proteins (PABPs) in nuclear mRNA biogenesis remain elusive. Here, we demonstrate that rapid nuclear depletion of the S. cerevisiae PABP Nab2p leads to a global loss of cellular mRNA, but not of RNA lacking poly(A) tails. Disappearance of mRNA is a nuclear event, but not due to decreased transcription. Instead, the absence of Nab2p results in robust nuclear mRNA decay by the ribonucleolytic RNA exosome in a polyadenylation-dependent process. We conclude that Nab2p is required to protect early mRNA and therefore constitutes a crucial nuclear mRNA biogenesis factor.
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Affiliation(s)
- Manfred Schmid
- Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Alle 3, Building 1130, 8000 Aarhus C., Denmark.
| | - Pawel Olszewski
- Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Alle 3, Building 1130, 8000 Aarhus C., Denmark
| | - Vicent Pelechano
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany
| | - Ishaan Gupta
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany
| | - Lars M Steinmetz
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany; Stanford Genome Technology Center, Stanford University, Palo Alto, CA 94304, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Torben Heick Jensen
- Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Alle 3, Building 1130, 8000 Aarhus C., Denmark.
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Wu H, Becker D, Krebber H. Telomerase RNA TLC1 shuttling to the cytoplasm requires mRNA export factors and is important for telomere maintenance. Cell Rep 2014; 8:1630-1638. [PMID: 25220466 DOI: 10.1016/j.celrep.2014.08.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 07/09/2014] [Accepted: 08/08/2014] [Indexed: 12/23/2022] Open
Abstract
Telomerases protect the ends of linear chromosomes from shortening. They are composed of an RNA (TLC1 in S. cerevisiae) and several proteins. TLC1 undergoes several maturation steps before it is exported into the cytoplasm to recruit the Est proteins for complete assembly. The mature telomerase is subsequently reimported into the nucleus, where it fulfills its function on telomeres. Here, we show that TLC1 export into the cytoplasm requires not only the Ran GTPase-dependent karyopherin Crm1/Xpo1 but also the mRNA export machinery. mRNA export factor mutants accumulate mature and export-competent TLC1 RNAs in their nuclei. Moreover, TLC1 physically interacts with the mRNA transport factors Mex67 and Dbp5/Rat8. Most importantly, we show that the nuclear export of TLC1 is an essential step for the formation of the functional RNA containing enzyme, because blocking TLC1 export in the mex67-5 xpo1-1 double mutant prevents its cytoplasmic maturation and leads to telomere shortening.
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Affiliation(s)
- Haijia Wu
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, 37077 Göttingen, Germany
| | - Daniel Becker
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, 37077 Göttingen, Germany
| | - Heike Krebber
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, 37077 Göttingen, Germany.
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Abstract
Eukaryotic mRNAs are extensively processed to generate functional transcripts, which are 5′ capped, spliced and 3′ polyadenylated. Accumulation of unprocessed (aberrant) mRNAs can be deleterious for the cell, hence processing fidelity is closely monitored by QC (quality control) mechanisms that identify erroneous transcripts and initiate their selective removal. Nucleases including Xrn2/Rat1 and the nuclear exosome have been shown to play an important role in the turnover of aberrant mRNAs. Recently, with the growing appreciation that mRNA processing occurs concomitantly with polII (RNA polymerase II) transcription, it has become evident that QC acts at the transcriptional level in addition to degrading aberrant RNAs. In the present review, we discuss mechanisms that allow cells to co-transcriptionally initiate the removal of RNAs as well as down-regulate transcription of transcripts where processing repeatedly fails.
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Boczonadi V, Müller JS, Pyle A, Munkley J, Dor T, Quartararo J, Ferrero I, Karcagi V, Giunta M, Polvikoski T, Birchall D, Princzinger A, Cinnamon Y, Lützkendorf S, Piko H, Reza M, Florez L, Santibanez-Koref M, Griffin H, Schuelke M, Elpeleg O, Kalaydjieva L, Lochmüller H, Elliott DJ, Chinnery PF, Edvardson S, Horvath R. EXOSC8 mutations alter mRNA metabolism and cause hypomyelination with spinal muscular atrophy and cerebellar hypoplasia. Nat Commun 2014; 5:4287. [PMID: 24989451 PMCID: PMC4102769 DOI: 10.1038/ncomms5287] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 06/03/2014] [Indexed: 12/21/2022] Open
Abstract
The exosome is a multi-protein complex, required for the degradation of AU-rich element (ARE) containing messenger RNAs (mRNAs). EXOSC8 is an essential protein of the exosome core, as its depletion causes a severe growth defect in yeast. Here we show that homozygous missense mutations in EXOSC8 cause progressive and lethal neurological disease in 22 infants from three independent pedigrees. Affected individuals have cerebellar and corpus callosum hypoplasia, abnormal myelination of the central nervous system or spinal motor neuron disease. Experimental downregulation of EXOSC8 in human oligodendroglia cells and in zebrafish induce a specific increase in ARE mRNAs encoding myelin proteins, showing that the imbalanced supply of myelin proteins causes the disruption of myelin, and explaining the clinical presentation. These findings show the central role of the exosomal pathway in neurodegenerative disease. The exosome is responsible for mRNA degradation, which is an important step in the regulation of gene expression. Here the authors report that homozygous missense mutations in the exosome subunit, EXOSC8, may cause neurodegenerative disease in infants through the dysregulation of myelin expression.
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Affiliation(s)
- Veronika Boczonadi
- 1] Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK [2]
| | - Juliane S Müller
- 1] Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK [2]
| | - Angela Pyle
- 1] Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK [2]
| | - Jennifer Munkley
- 1] Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK [2]
| | - Talya Dor
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah- Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Jade Quartararo
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11A, Parma 43124, Italy
| | - Ileana Ferrero
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11A, Parma 43124, Italy
| | - Veronika Karcagi
- Department of Molecular Genetics and Diagnostics, NIEH, Albert Florian ut 2-6, Budapest 1097, Hungary
| | - Michele Giunta
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Tuomo Polvikoski
- Department of Pathology, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK
| | - Daniel Birchall
- Neuroradiology Department, Regional Neurosciences Centre, Queen Victoria Road, Newcastle upon Tyne NE1 4PL, UK
| | - Agota Princzinger
- Department of Paediatrics, Josa Andras Hospital, Szent Istvan utca 6, Nyiregyhaza 4400, Hungary
| | - Yuval Cinnamon
- 1] The Monique and Jacques Roboh Department of Genetic Research, Hadassah- Hebrew University Medical Center, Jerusalem 91120, Israel [2] Department of Poultry and Aquaculture Sciences, Institute of Animal Science, Agricultural Research Organization, The Volcani Center, P.O.Box 6, Bet Dagan 50250, Israel
| | - Susanne Lützkendorf
- Department of Neuropediatrics and NeuroCure Clinical Research Center, Charité-Universitätsmedizin, Charité-Platz 1, 10117 Berlin, Germany
| | - Henriett Piko
- Department of Molecular Genetics and Diagnostics, NIEH, Albert Florian ut 2-6, Budapest 1097, Hungary
| | - Mojgan Reza
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Laura Florez
- Western Australian Institute for Medical Research/Centre for Medical Research, The University of Western Australia, 35 Stirling Highway Crawley, Western Australia 6009 Perth, Australia
| | - Mauro Santibanez-Koref
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Helen Griffin
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Markus Schuelke
- Department of Neuropediatrics and NeuroCure Clinical Research Center, Charité-Universitätsmedizin, Charité-Platz 1, 10117 Berlin, Germany
| | - Orly Elpeleg
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah- Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Luba Kalaydjieva
- Western Australian Institute for Medical Research/Centre for Medical Research, The University of Western Australia, 35 Stirling Highway Crawley, Western Australia 6009 Perth, Australia
| | - Hanns Lochmüller
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - David J Elliott
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Patrick F Chinnery
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Shimon Edvardson
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah- Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Rita Horvath
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
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Mefford MA, Rafiq Q, Zappulla DC. RNA connectivity requirements between conserved elements in the core of the yeast telomerase RNP. EMBO J 2013; 32:2980-93. [PMID: 24129512 DOI: 10.1038/emboj.2013.227] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 09/23/2013] [Indexed: 12/25/2022] Open
Abstract
Telomerase is a specialized chromosome end-replicating enzyme required for genome duplication in many eukaryotes. An RNA and reverse transcriptase protein subunit comprise its enzymatic core. Telomerase is evolving rapidly, particularly its RNA component. Nevertheless, nearly all telomerase RNAs, including those of H. sapiens and S. cerevisiae, share four conserved structural elements: a core-enclosing helix (CEH), template-boundary element, template, and pseudoknot, in this order along the RNA. It is not clear how these elements coordinate telomerase activity. We find that although rearranging the order of the four conserved elements in the yeast telomerase RNA subunit, TLC1, disrupts activity, the RNA ends can be moved between the template and pseudoknot in vitro and in vivo. However, the ends disrupt activity when inserted between the other structured elements, defining an Area of Required Connectivity (ARC). Within the ARC, we find that only the junction nucleotides between the pseudoknot and CEH are essential. Integrating all of our findings provides a basic map of functional connections in the core of the yeast telomerase RNP and a framework to understand conserved element coordination in telomerase mechanism.
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Affiliation(s)
- Melissa A Mefford
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
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