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Mauxion F, Séraphin B. An RNA-Ligation-Based RACE-PAT Assay to Monitor Poly(A) Tail Length of mRNAs of Interest. Methods Mol Biol 2024; 2723:113-123. [PMID: 37824067 DOI: 10.1007/978-1-0716-3481-3_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
In eukaryotes, a non-templated poly-adenosine (poly(A)) tail is added co-transcriptionally to almost every messenger RNA (mRNA). The length of this poly(A) tail changes during the lifetime of mRNAs and has been shown in many circumstances to be an important factor controlling transcript fates. Yet, the measure of the length of this homogenous nucleotide sequence is technically challenging, making it difficult to assess its dynamic variation. In this chapter, we describe an RNA-ligation-based RACE-PAT (Rapid Amplification of cDNA End-Poly(A) Tail) assay to monitor the poly(A) tail length of mRNAs. In the first step, an RNA oligonucleotide is ligated to mRNA 3' ends providing an anchoring site to prime cDNA synthesis, avoiding the bias introduced by oligo(dT)-derived primers. Afterward, reverse transcription is performed with an anchor primer with a unique 5' extension. The choice of the oligonucleotide 3' end at this step allows further flexibility to amplify modified tails, for example, by uridylation. Next, short DNA fragments encompassing the poly(A) tails are amplified by Polymerase Chain Reaction (PCR) using as forward primer, a transcript-specific primer hybridizing close to the transcript polyadenylation signal, and as reverse primer, an oligonucleotide corresponding to the 5' extension of the primer used for cDNA synthesis, ensuring that only cDNAs are amplified. The resulting DNA fragments are then visualized after size fractionation by electrophoresis. This method does not provide exact nucleotide count and composition but has the advantage of allowing the processing of many samples in parallel at a low cost.
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Affiliation(s)
- Fabienne Mauxion
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de Recherche Scientifique (CNRS) UMR 7104 - Institut National de Santé et de Recherche Médicale (Inserm) U1258 - Université de Strasbourg, Illkirch, France.
| | - Bertrand Séraphin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de Recherche Scientifique (CNRS) UMR 7104 - Institut National de Santé et de Recherche Médicale (Inserm) U1258 - Université de Strasbourg, Illkirch, France
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2
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Huntzinger E, Sinteff J, Morlet B, Séraphin B. HELZ2: a new, interferon-regulated, human 3'-5' exoribonuclease of the RNB family is expressed from a non-canonical initiation codon. Nucleic Acids Res 2023; 51:9279-9293. [PMID: 37602378 PMCID: PMC10516660 DOI: 10.1093/nar/gkad673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 07/27/2023] [Accepted: 08/10/2023] [Indexed: 08/22/2023] Open
Abstract
Proteins containing a RNB domain, originally identified in Escherichia coli RNase II, are widely present throughout the tree of life. Many RNB proteins have 3'-5' exoribonucleolytic activity but some have lost catalytic activity during evolution. Database searches identified a new RNB domain-containing protein in human: HELZ2. Analysis of genomic and expression data combined with evolutionary information suggested that the human HELZ2 protein is produced from an unforeseen non-canonical initiation codon in Hominidae. This unusual property was confirmed experimentally, extending the human protein by 247 residues. Human HELZ2 was further shown to be an active ribonuclease despite the substitution of a key residue in its catalytic center. HELZ2 RNase activity is lost in cells from some cancer patients as a result of somatic mutations. HELZ2 harbors also two RNA helicase domains and several zinc fingers and its expression is induced by interferon treatment. We demonstrate that HELZ2 is able to degrade structured RNAs through the coordinated ATP-dependent displacement of duplex RNA mediated by its RNA helicase domains and its 3'-5' ribonucleolytic action. The expression characteristics and biochemical properties of HELZ2 support a role for this factor in response to viruses and/or mobile elements.
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Affiliation(s)
- Eric Huntzinger
- Institut de Génétique et de Biologie Moléculaire et cellulaire (IGBMC), Centre National de Recherche scientifique (CNRS) UMR 7104 - Institut National de santé et de Recherche Médicale (Inserm) U1258 - Université de Strasbourg, 1 rue Laurent Fries, Illkirch, France
| | - Jordan Sinteff
- Institut de Génétique et de Biologie Moléculaire et cellulaire (IGBMC), Centre National de Recherche scientifique (CNRS) UMR 7104 - Institut National de santé et de Recherche Médicale (Inserm) U1258 - Université de Strasbourg, 1 rue Laurent Fries, Illkirch, France
| | - Bastien Morlet
- Institut de Génétique et de Biologie Moléculaire et cellulaire (IGBMC), Centre National de Recherche scientifique (CNRS) UMR 7104 - Institut National de santé et de Recherche Médicale (Inserm) U1258 - Université de Strasbourg, 1 rue Laurent Fries, Illkirch, France
| | - Bertrand Séraphin
- Institut de Génétique et de Biologie Moléculaire et cellulaire (IGBMC), Centre National de Recherche scientifique (CNRS) UMR 7104 - Institut National de santé et de Recherche Médicale (Inserm) U1258 - Université de Strasbourg, 1 rue Laurent Fries, Illkirch, France
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3
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Scutenaire J, Plassard D, Matelot M, Villa T, Zumsteg J, Libri D, Séraphin B. The S. cerevisiae m6A-reader Pho92 promotes timely meiotic recombination by controlling key methylated transcripts. Nucleic Acids Res 2022; 51:517-535. [PMID: 35934316 PMCID: PMC9881176 DOI: 10.1093/nar/gkac640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 07/05/2022] [Accepted: 07/20/2022] [Indexed: 02/06/2023] Open
Abstract
N6-Methyladenosine (m6A), one of the most abundant internal modification of eukaryotic mRNAs, participates in the post-transcriptional control of gene expression through recruitment of specific m6A readers. In Saccharomyces cerevisiae, the m6A methyltransferase Ime4 is expressed only during meiosis and its deletion impairs this process. To elucidate how m6A control gene expression, we investigated the function of the budding yeast m6A reader Pho92. We show that Pho92 is an early meiotic factor that promotes timely meiotic progression. High-throughput RNA sequencing and mapping of Pho92-binding sites following UV-crosslinking reveal that Pho92 is recruited to specific mRNAs in an m6A-dependent manner during the meiotic prophase, preceding their down-regulation. Strikingly, point mutations altering m6A sites in mRNAs targeted by Pho92 are sufficient to delay their down-regulation and, in one case, to slow down meiotic progression. Altogether, our results indicate that Pho92 facilitate the meiotic progression by accelerating the down-regulation of timely-regulated mRNAs during meiotic recombination.
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Affiliation(s)
- Jérémy Scutenaire
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France,Centre National de Recherche Scientifique (CNRS) UMR 7104, 67400 Illkirch, France,Institut National de Santé et de Recherche Médicale (INSERM) U1258, 67400 Illkirch, France,Université de Strasbourg, 67400 Illkirch, France
| | - Damien Plassard
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France,Centre National de Recherche Scientifique (CNRS) UMR 7104, 67400 Illkirch, France,Institut National de Santé et de Recherche Médicale (INSERM) U1258, 67400 Illkirch, France,Université de Strasbourg, 67400 Illkirch, France
| | - Mélody Matelot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France,Centre National de Recherche Scientifique (CNRS) UMR 7104, 67400 Illkirch, France,Institut National de Santé et de Recherche Médicale (INSERM) U1258, 67400 Illkirch, France,Université de Strasbourg, 67400 Illkirch, France
| | - Tommaso Villa
- Université de Paris Cité, CNRS, Institut Jacques Monod, 75006 Paris, France
| | - Julie Zumsteg
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| | - Domenico Libri
- Université de Paris Cité, CNRS, Institut Jacques Monod, 75006 Paris, France
| | - Bertrand Séraphin
- To whom correspondence should be addressed. Tel: +33 3 88 65 33 36; Fax: +33 3 88 65 32 01;
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Amine H, Ripin N, Sharma S, Stoecklin G, Allain FH, Séraphin B, Mauxion F. A conserved motif in human BTG1 and BTG2 proteins mediates interaction with the poly(A) binding protein PABPC1 to stimulate mRNA deadenylation. RNA Biol 2021; 18:2450-2465. [PMID: 34060423 PMCID: PMC8632095 DOI: 10.1080/15476286.2021.1925476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Antiproliferative BTG/Tob proteins interact directly with the CAF1 deadenylase subunit of the CCR4-NOT complex. This binding requires the presence of two conserved motifs, boxA and boxB, characteristic of the BTG/Tob APRO domain. Consistently, these proteins were shown to stimulate mRNA deadenylation and decay in several instances. Two members of the family, BTG1 and BTG2, were reported further to associate with the protein arginine methyltransferase PRMT1 through a motif, boxC, conserved only in this subset of proteins. We recently demonstrated that BTG1 and BTG2 also contact the first RRM domain of the cytoplasmic poly(A) binding protein PABPC1. To decipher the mode of interaction of BTG1 and BTG2 with partners, we performed nuclear magnetic resonance experiments as well as mutational and biochemical analyses. Our data demonstrate that, in the context of an APRO domain, the boxC motif is necessary and sufficient to allow interaction with PABPC1 but, unexpectedly, that it is not required for BTG2 association with PRMT1. We show further that the presence of a boxC motif in an APRO domain endows it with the ability to stimulate deadenylation in cellulo and in vitro. Overall, our results identify the molecular interface allowing BTG1 and BTG2 to activate deadenylation, a process recently shown to be necessary for maintaining T-cell quiescence.
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Affiliation(s)
- Hamza Amine
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de Recherche Scientifique (CNRS) UMR 7104, Illkirch, France.,Institut National de Santé et de Recherche Médicale (INSERM) U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Nina Ripin
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, Switzerland
| | - Sahil Sharma
- Mannheim Institute for Innate Immunoscience (MI3), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,German Cancer Research Center (DKFZ)-ZMBH Alliance, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
| | - Georg Stoecklin
- Mannheim Institute for Innate Immunoscience (MI3), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,German Cancer Research Center (DKFZ)-ZMBH Alliance, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
| | - Frédéric H Allain
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, Switzerland.,Department of Biology, Institute of Biochemistry, ETH Zürich, Switzerland
| | - Bertrand Séraphin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de Recherche Scientifique (CNRS) UMR 7104, Illkirch, France.,Institut National de Santé et de Recherche Médicale (INSERM) U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Fabienne Mauxion
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de Recherche Scientifique (CNRS) UMR 7104, Illkirch, France.,Institut National de Santé et de Recherche Médicale (INSERM) U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
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5
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Charenton C, Gaudon-Plesse C, Back R, Ulryck N, Cosson L, Séraphin B, Graille M. Pby1 is a direct partner of the Dcp2 decapping enzyme. Nucleic Acids Res 2020; 48:6353-6366. [PMID: 32396195 PMCID: PMC7293026 DOI: 10.1093/nar/gkaa337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/17/2020] [Accepted: 04/23/2020] [Indexed: 12/27/2022] Open
Abstract
Most eukaryotic mRNAs harbor a characteristic 5′ m7GpppN cap that promotes pre-mRNA splicing, mRNA nucleocytoplasmic transport and translation while also protecting mRNAs from exonucleolytic attacks. mRNA caps are eliminated by Dcp2 during mRNA decay, allowing 5′-3′ exonucleases to degrade mRNA bodies. However, the Dcp2 decapping enzyme is poorly active on its own and requires binding to stable or transient protein partners to sever the cap of target mRNAs. Here, we analyse the role of one of these partners, the yeast Pby1 factor, which is known to co-localize into P-bodies together with decapping factors. We report that Pby1 uses its C-terminal domain to directly bind to the decapping enzyme. We solved the structure of this Pby1 domain alone and bound to the Dcp1–Dcp2–Edc3 decapping complex. Structure-based mutant analyses reveal that Pby1 binding to the decapping enzyme is required for its recruitment into P-bodies. Moreover, Pby1 binding to the decapping enzyme stimulates growth in conditions in which decapping activation is compromised. Our results point towards a direct connection of Pby1 with decapping and P-body formation, both stemming from its interaction with the Dcp1–Dcp2 holoenzyme.
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Affiliation(s)
- Clément Charenton
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris, 91128 Palaiseau, France
| | - Claudine Gaudon-Plesse
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de Recherche Scientifique (CNRS) UMR 7104, Illkirch, France.,Institut National de Santé et de Recherche Médicale (INSERM) U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Régis Back
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris, 91128 Palaiseau, France
| | - Nathalie Ulryck
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris, 91128 Palaiseau, France
| | - Loreline Cosson
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris, 91128 Palaiseau, France
| | - Bertrand Séraphin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de Recherche Scientifique (CNRS) UMR 7104, Illkirch, France.,Institut National de Santé et de Recherche Médicale (INSERM) U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Marc Graille
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris, 91128 Palaiseau, France
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O’Connell AE, Gerashchenko MV, O’Donohue MF, Rosen SM, Huntzinger E, Gleeson D, Galli A, Ryder E, Cao S, Murphy Q, Kazerounian S, Morton SU, Schmitz-Abe K, Gladyshev VN, Gleizes PE, Séraphin B, Agrawal PB. Mammalian Hbs1L deficiency causes congenital anomalies and developmental delay associated with Pelota depletion and 80S monosome accumulation. PLoS Genet 2019; 15:e1007917. [PMID: 30707697 PMCID: PMC6373978 DOI: 10.1371/journal.pgen.1007917] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 02/13/2019] [Accepted: 12/25/2018] [Indexed: 12/18/2022] Open
Abstract
Hbs1 has been established as a central component of the cell's translational quality control pathways in both yeast and prokaryotic models; however, the functional characteristics of its human ortholog (Hbs1L) have not been well-defined. We recently reported a novel human phenotype resulting from a mutation in the critical coding region of the HBS1L gene characterized by facial dysmorphism, severe growth restriction, axial hypotonia, global developmental delay and retinal pigmentary deposits. Here we further characterize downstream effects of the human HBS1L mutation. HBS1L has three transcripts in humans, and RT-PCR demonstrated reduced mRNA levels corresponding with transcripts V1 and V2 whereas V3 expression was unchanged. Western blot analyses revealed Hbs1L protein was absent in the patient cells. Additionally, polysome profiling revealed an abnormal aggregation of 80S monosomes in patient cells under baseline conditions. RNA and ribosomal sequencing demonstrated an increased translation efficiency of ribosomal RNA in Hbs1L-deficient fibroblasts, suggesting that there may be a compensatory increase in ribosome translation to accommodate the increased 80S monosome levels. This enhanced translation was accompanied by upregulation of mTOR and 4-EBP protein expression, suggesting an mTOR-dependent phenomenon. Furthermore, lack of Hbs1L caused depletion of Pelota protein in both patient cells and mouse tissues, while PELO mRNA levels were unaffected. Inhibition of proteasomal function partially restored Pelota expression in human Hbs1L-deficient cells. We also describe a mouse model harboring a knockdown mutation in the murine Hbs1l gene that shared several of the phenotypic elements observed in the Hbs1L-deficient human including facial dysmorphism, growth restriction and retinal deposits. The Hbs1lKO mice similarly demonstrate diminished Pelota levels that were rescued by proteasome inhibition.
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Affiliation(s)
- Amy E. O’Connell
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Maxim V. Gerashchenko
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Marie-Francoise O’Donohue
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Samantha M. Rosen
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Eric Huntzinger
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Université de Strasbourg, Centre National de La Recherche Scientifique UMR 7104, INSERM U964, Strasbourg, France
| | - Diane Gleeson
- Wellcome Sanger Institute, Cambridge, United Kingdom
| | | | - Edward Ryder
- Wellcome Sanger Institute, Cambridge, United Kingdom
| | - Siqi Cao
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Quinn Murphy
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Shideh Kazerounian
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Sarah U. Morton
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Klaus Schmitz-Abe
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Vadim N. Gladyshev
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Pierre-Emmanuel Gleizes
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Bertrand Séraphin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Université de Strasbourg, Centre National de La Recherche Scientifique UMR 7104, INSERM U964, Strasbourg, France
| | - Pankaj B. Agrawal
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
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Sharma S, Poetz F, Bruer M, Ly-Hartig TBN, Schott J, Séraphin B, Stoecklin G. Acetylation-Dependent Control of Global Poly(A) RNA Degradation by CBP/p300 and HDAC1/2. Mol Cell 2017; 63:927-38. [PMID: 27635759 DOI: 10.1016/j.molcel.2016.08.030] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 05/09/2016] [Accepted: 08/24/2016] [Indexed: 12/31/2022]
Abstract
Acetylation of histones and transcription-related factors is known to exert epigenetic and transcriptional control of gene expression. Here we report that histone acetyltransferases (HATs) and histone deacetylases (HDACs) also regulate gene expression at the posttranscriptional level by controlling poly(A) RNA stability. Inhibition of HDAC1 and HDAC2 induces massive and widespread degradation of normally stable poly(A) RNA in mammalian and Drosophila cells. Acetylation-induced RNA decay depends on the HATs p300 and CBP, which acetylate the exoribonuclease CAF1a, a catalytic subunit of the CCR4-CAF1-NOT deadenlyase complex and thereby contribute to accelerating poly(A) RNA degradation. Taking adipocyte differentiation as a model, we observe global stabilization of poly(A) RNA during differentiation, concomitant with loss of CBP/p300 expression. Our study uncovers reversible acetylation as a fundamental switch by which HATs and HDACs control the overall turnover of poly(A) RNA.
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Affiliation(s)
- Sahil Sharma
- Division of Biochemistry, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany; Center for Molecular Biology of Heidelberg University (ZMBH), 69120 Heidelberg, Germany; German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Fabian Poetz
- Division of Biochemistry, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany; Center for Molecular Biology of Heidelberg University (ZMBH), 69120 Heidelberg, Germany; German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Marius Bruer
- Division of Biochemistry, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany; Center for Molecular Biology of Heidelberg University (ZMBH), 69120 Heidelberg, Germany; German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Thi Bach Nga Ly-Hartig
- Division of Biochemistry, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany; Center for Molecular Biology of Heidelberg University (ZMBH), 69120 Heidelberg, Germany; German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Johanna Schott
- Division of Biochemistry, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany; Center for Molecular Biology of Heidelberg University (ZMBH), 69120 Heidelberg, Germany; German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Bertrand Séraphin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch, France; Centre National de Recherche Scientifique (CNRS) UMR 7104, 67404 Illkirch, France; INSERM U964, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, France
| | - Georg Stoecklin
- Division of Biochemistry, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany; Center for Molecular Biology of Heidelberg University (ZMBH), 69120 Heidelberg, Germany; German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany.
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8
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van Roon AMM, Oubridge C, Obayashi E, Sposito B, Newman AJ, Séraphin B, Nagai K. Crystal structure of U2 snRNP SF3b components: Hsh49p in complex with Cus1p-binding domain. RNA 2017; 23:968-981. [PMID: 28348170 PMCID: PMC5435868 DOI: 10.1261/rna.059378.116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 03/17/2017] [Indexed: 05/02/2023]
Abstract
Spliceosomal proteins Hsh49p and Cus1p are components of SF3b, which together with SF3a, Msl1p/Lea1p, Sm proteins, and U2 snRNA, form U2 snRNP, which plays a crucial role in pre-mRNA splicing. Hsh49p, comprising two RRMs, forms a heterodimer with Cus1p. We determined the crystal structures of Saccharomyces cerevisiae full-length Hsh49p as well as its RRM1 in complex with a minimal binding region of Cus1p (residues 290-368). The structures show that the Cus1 fragment binds to the α-helical surface of Hsh49p RRM1, opposite the four-stranded β-sheet, leaving the canonical RNA-binding surface available to bind RNA. Hsh49p binds the 5' end region of U2 snRNA via RRM1. Its affinity is increased in complex with Cus1(290-368)p, partly because an extended RNA-binding surface forms across the protein-protein interface. The Hsh49p RRM1-Cus1(290-368)p structure fits well into cryo-EM density of the Bact spliceosome, corroborating the biological relevance of our crystal structure.
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Affiliation(s)
| | - Chris Oubridge
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Eiji Obayashi
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Benedetta Sposito
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Andrew J Newman
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Bertrand Séraphin
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de la Recherche Scientifique (CNRS) UMR 7104/Institut National de la Santé et de la Recherche Médicale (INSERM), U964/Université de Strasbourg, 67404 Illkirch, France
| | - Kiyoshi Nagai
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
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9
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10
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Dauden MI, Kosinski J, Kolaj-Robin O, Desfosses A, Ori A, Faux C, Hoffmann NA, Onuma OF, Breunig KD, Beck M, Sachse C, Séraphin B, Glatt S, Müller CW. Architecture of the yeast Elongator complex. EMBO Rep 2016; 18:264-279. [PMID: 27974378 PMCID: PMC5286394 DOI: 10.15252/embr.201643353] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/20/2016] [Accepted: 11/08/2016] [Indexed: 11/09/2022] Open
Abstract
The highly conserved eukaryotic Elongator complex performs specific chemical modifications on wobble base uridines of tRNAs, which are essential for proteome stability and homeostasis. The complex is formed by six individual subunits (Elp1-6) that are all equally important for its tRNA modification activity. However, its overall architecture and the detailed reaction mechanism remain elusive. Here, we report the structures of the fully assembled yeast Elongator and the Elp123 sub-complex solved by an integrative structure determination approach showing that two copies of the Elp1, Elp2, and Elp3 subunits form a two-lobed scaffold, which binds Elp456 asymmetrically. Our topological models are consistent with previous studies on individual subunits and further validated by complementary biochemical analyses. Our study provides a structural framework on how the tRNA modification activity is carried out by Elongator.
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Affiliation(s)
- Maria I Dauden
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
| | - Jan Kosinski
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
| | - Olga Kolaj-Robin
- Université de Strasbourg, IGBMC, Illkirch, France.,CNRS, IGBMC UMR 7104, Illkirch, France.,Inserm, IGBMC U964, Illkirch, France
| | - Ambroise Desfosses
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
| | - Alessandro Ori
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
| | - Celine Faux
- Université de Strasbourg, IGBMC, Illkirch, France.,CNRS, IGBMC UMR 7104, Illkirch, France.,Inserm, IGBMC U964, Illkirch, France
| | - Niklas A Hoffmann
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
| | - Osita F Onuma
- Institute of Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Karin D Breunig
- Institute of Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Martin Beck
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
| | - Carsten Sachse
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
| | - Bertrand Séraphin
- Université de Strasbourg, IGBMC, Illkirch, France.,CNRS, IGBMC UMR 7104, Illkirch, France.,Inserm, IGBMC U964, Illkirch, France
| | - Sebastian Glatt
- Max Planck Research Group at the Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Christoph W Müller
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
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11
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Stupfler B, Birck C, Séraphin B, Mauxion F. BTG2 bridges PABPC1 RNA-binding domains and CAF1 deadenylase to control cell proliferation. Nat Commun 2016; 7:10811. [PMID: 26912148 PMCID: PMC4773420 DOI: 10.1038/ncomms10811] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 01/24/2016] [Indexed: 12/12/2022] Open
Abstract
While BTG2 plays an important role in cellular differentiation and cancer, its precise molecular function remains unclear. BTG2 interacts with CAF1 deadenylase through its APRO domain, a defining feature of BTG/Tob factors. Our previous experiments revealed that expression of BTG2 promoted mRNA poly(A) tail shortening through an undefined mechanism. Here we report that the APRO domain of BTG2 interacts directly with the first RRM domain of the poly(A)-binding protein PABPC1. Moreover, PABPC1 RRM and BTG2 APRO domains are sufficient to stimulate CAF1 deadenylase activity in vitro in the absence of other CCR4–NOT complex subunits. Our results unravel thus the mechanism by which BTG2 stimulates mRNA deadenylation, demonstrating its direct role in poly(A) tail length control. Importantly, we also show that the interaction of BTG2 with the first RRM domain of PABPC1 is required for BTG2 to control cell proliferation. BTG2 promotes mRNA poly(A) tail shortening and regulates cellular differentiation. Here, Stupfler et al. show that the BTG2 APRO domain interacts with PABPC1 RRM1, allowing the former to recruit and stimulate the poly(A) tail shortening activity of CAF1 deadenylase and to control cell proliferation.
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Affiliation(s)
- Benjamin Stupfler
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France.,Centre National de la Recherche Scientifique UMR7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| | - Catherine Birck
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France.,Centre National de la Recherche Scientifique UMR7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| | - Bertrand Séraphin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France.,Centre National de la Recherche Scientifique UMR7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| | - Fabienne Mauxion
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France.,Centre National de la Recherche Scientifique UMR7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale U964, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
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12
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Martínez-Lumbreras S, Taverniti V, Zorrilla S, Séraphin B, Pérez-Cañadillas JM. Gbp2 interacts with THO/TREX through a novel type of RRM domain. Nucleic Acids Res 2015; 44:437-48. [PMID: 26602689 PMCID: PMC4705658 DOI: 10.1093/nar/gkv1303] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 11/07/2015] [Indexed: 12/11/2022] Open
Abstract
Metazoan SR and SR-like proteins are important regulatory factors in RNA splicing, export, translation and RNA decay. We determined the NMR structures and nucleic acid interaction modes of Gbp2 and Hrb1, two paralogous budding yeast proteins with similarities to mammalian SR proteins. Gbp2 RRM1 and RRM2 recognise preferentially RNAs containing the core motif GGUG. Sequence selectivity resides in a non-canonical interface in RRM2 that is highly related to the SRSF1 pseudoRRM. The atypical Gbp2/Hrb1 C-terminal RRM domains (RRM3) do not interact with RNA/DNA, likely because of their novel N-terminal extensions that block the canonical RNA binding interface. Instead, we discovered that RRM3 is crucial for interaction with the THO/TREX complex and identified key residues essential for this interaction. Moreover, Gbp2 interacts genetically with Tho2 as the double deletion shows a synthetic phenotype and preventing Gbp2 interaction with the THO/TREX complex partly supresses gene expression defect associated with inactivation of the latter complex. These findings provide structural and functional insights into the contribution of SR-like proteins in the post-transcriptional control of gene expression.
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Affiliation(s)
- Santiago Martínez-Lumbreras
- Department of Biological Physical Chemistry, Instituto de Química-Física 'Rocasolano', CSIC, Serrano-119, 28006 Madrid, Spain
| | - Valerio Taverniti
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGMBC), Centre National de Recherche Scientifique (CNRS) UMR 7104/Institut National de Santé et de Recherche Médicale (INSERM) U964/Université de Strasbourg, 67404 Illkirch, France
| | - Silvia Zorrilla
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Bertrand Séraphin
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGMBC), Centre National de Recherche Scientifique (CNRS) UMR 7104/Institut National de Santé et de Recherche Médicale (INSERM) U964/Université de Strasbourg, 67404 Illkirch, France
| | - José Manuel Pérez-Cañadillas
- Department of Biological Physical Chemistry, Instituto de Química-Física 'Rocasolano', CSIC, Serrano-119, 28006 Madrid, Spain
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13
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Ng CKL, Shboul M, Taverniti V, Bonnard C, Lee H, Eskin A, Nelson SF, Al-Raqad M, Altawalbeh S, Séraphin B, Reversade B. Loss of the scavenger mRNA decapping enzyme DCPS causes syndromic intellectual disability with neuromuscular defects. Hum Mol Genet 2015; 24:3163-71. [PMID: 25712129 PMCID: PMC4424953 DOI: 10.1093/hmg/ddv067] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 02/16/2015] [Indexed: 12/23/2022] Open
Abstract
mRNA decay is an essential and active process that allows cells to continuously adapt gene expression to internal and environmental cues. There are two mRNA degradation pathways: 3′ to 5′ and 5′ to 3′. The DCPS protein is the scavenger mRNA decapping enzyme which functions in the last step of the 3′ end mRNA decay pathway. We have identified a DCPS pathogenic mutation in a large family with three affected individuals presenting with a novel recessive syndrome consisting of craniofacial anomalies, intellectual disability and neuromuscular defects. Using patient's primary cells, we show that this homozygous splice mutation results in a DCPS loss-of-function allele. Diagnostic biochemical analyses using various m7G cap derivatives as substrates reveal no DCPS enzymatic activity in patient's cells. Our results implicate DCPS and more generally RNA catabolism, as a critical cellular process for neurological development, normal cognition and organismal homeostasis in humans.
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Affiliation(s)
- Calista K L Ng
- Institute of Medical Biology, A*STAR, 8A Biomedical Grove, Singapore 138648, Singapore
| | - Mohammad Shboul
- Institute of Medical Biology, A*STAR, 8A Biomedical Grove, Singapore 138648, Singapore
| | - Valerio Taverniti
- IGBMC, CNRS UMR 1704/INSERM U964/Université de Strasbourg, Illkirch, France
| | - Carine Bonnard
- Institute of Medical Biology, A*STAR, 8A Biomedical Grove, Singapore 138648, Singapore
| | - Hane Lee
- Department of Pathology and Laboratory Medicine
| | - Ascia Eskin
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Stanley F Nelson
- Department of Pathology and Laboratory Medicine Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Mohammed Al-Raqad
- Queen Rania Paediatric Hospital, King Hussein Medical Centre, Royal Medical Services, Amman, Jordan
| | - Samah Altawalbeh
- Queen Rania Paediatric Hospital, King Hussein Medical Centre, Royal Medical Services, Amman, Jordan
| | - Bertrand Séraphin
- IGBMC, CNRS UMR 1704/INSERM U964/Université de Strasbourg, Illkirch, France
| | - Bruno Reversade
- Institute of Medical Biology, A*STAR, 8A Biomedical Grove, Singapore 138648, Singapore Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
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14
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Kolaj-Robin O, McEwen AG, Cavarelli J, Séraphin B. Structure of the Elongator cofactor complex Kti11/Kti13 provides insight into the role of Kti13 in Elongator-dependent tRNA modification. FEBS J 2015; 282:819-33. [PMID: 25604895 DOI: 10.1111/febs.13199] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 01/12/2015] [Accepted: 01/14/2015] [Indexed: 12/26/2022]
Abstract
UNLABELLED Modification of wobble uridines of many eukaryotic tRNAs requires the Elongator complex, a highly conserved six-subunit eukaryotic protein assembly, as well as the Killer toxin-insensitive (Kti) proteins 11-14. Kti11 was additionally shown to be implicated in the biosynthesis of diphthamide, a post-translationally modified histidine of translation elongation factor 2. Recent data indicate that iron-bearing Kti11 functions as an electron donor to the [4Fe-4S] cluster of radical S-Adenosylmethionine enzymes, triggering the subsequent radical reaction. We show here that recombinant yeast Kti11 forms a stable 1 : 1 complex with Kti13. To obtain insights into the function of this heterodimer, the Kti11/Kti13 complex was purified to homogeneity, crystallized, and its structure determined at 1.45 Å resolution. The importance of several residues mediating complex formation was confirmed by mutagenesis. Kti13 adopts a fold characteristic of RCC1-like proteins. The seven-bladed β-propeller consists of a unique mixture of four- and three-stranded blades. In the complex, Kti13 orients Kti11 and restricts access to its electron-carrying iron atom, constraining the electron transfer capacity of Kti11. Based on these findings, we propose a role for Kti13, and discuss the possible functional implications of complex formation. DATABASE Structural data have been submitted to the Protein Data Bank under accession number 4X33.
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Affiliation(s)
- Olga Kolaj-Robin
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de Recherche Scientifique UMR 7104/Institut National de Santé et de Recherche Médicale U964/Université de Strasbourg, Illkirch, France
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15
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Taverniti V, Séraphin B. Elimination of cap structures generated by mRNA decay involves the new scavenger mRNA decapping enzyme Aph1/FHIT together with DcpS. Nucleic Acids Res 2014; 43:482-92. [PMID: 25432955 PMCID: PMC4288156 DOI: 10.1093/nar/gku1251] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Eukaryotic 5' mRNA cap structures participate to the post-transcriptional control of gene expression before being released by the two main mRNA decay pathways. In the 3'-5' pathway, the exosome generates free cap dinucleotides (m7GpppN) or capped oligoribonucleotides that are hydrolyzed by the Scavenger Decapping Enzyme (DcpS) forming m7GMP. In the 5'-3' pathway, the decapping enzyme Dcp2 generates m7GDP. We investigated the fate of m7GDP and m7GpppN produced by RNA decay in extracts and cells. This defined a pathway involving DcpS, NTPs and the nucleoside diphosphate kinase for m7GDP elimination. Interestingly, we identified and characterized in vitro and in vivo a new scavenger decapping enzyme involved in m7GpppN degradation. We show that activities mediating cap elimination identified in yeast are essentially conserved in human. Their alteration may contribute to pathologies, possibly through the interference of cap (di)nucleotide with cellular function.
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Affiliation(s)
- Valerio Taverniti
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de Recherche Scientifique (CNRS) UMR 7104/Institut National de Santé et de Recherche Médicale (INSERM) U964/Université de Strasbourg, 67404 Illkirch, France
| | - Bertrand Séraphin
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de Recherche Scientifique (CNRS) UMR 7104/Institut National de Santé et de Recherche Médicale (INSERM) U964/Université de Strasbourg, 67404 Illkirch, France
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16
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Abstract
Splicing reactions generally combine high speed with accuracy. However, some of the pre-mRNAs escape the nucleus with a retained intron. Intron retention can control gene expression and increase proteome diversity. We calculated the escape rate for the yeast PTC7 intron and pre-mRNA. This prediction was facilitated by the observation that splicing is a linear process and by deriving simple algebraic expressions from a model of co- and post-transcriptional splicing and RNA surveillance that determines the rate of the nonsense-mediated decay (NMD) of the pre-mRNAs with the retained intron. The escape rate was consistent with the observed threshold of splicing rate below which the mature mRNA level declined. When an mRNA contains multiple introns, the outcome of splicing becomes more difficult to predict since not only the escape rate of the pre-mRNA has to be considered, but also the possibility that the splicing of each intron is influenced by the others. We showed that the two adjacent introns in the SUS1 mRNA are spliced cooperatively, but this does not counteract the escape of the partially spliced mRNA. These findings will help to infer promoter activity and to predict the behavior of and to control splicing regulatory networks.
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Affiliation(s)
- Marie Mi Bonde
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Sylvia Voegeli
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Antoine Baudrimont
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Bertrand Séraphin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de Recherche Scientifique (CNRS) UMR 7104, Institut National de Santé et de Recherche Médicale (INSERM) U964, Université de Strasbourg, Illkirch, Strasbourg, France
| | - Attila Becskei
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
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17
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Decourty L, Doyen A, Malabat C, Frachon E, Rispal D, Séraphin B, Feuerbach F, Jacquier A, Saveanu C. Long Open Reading Frame Transcripts Escape Nonsense-Mediated mRNA Decay in Yeast. Cell Rep 2014; 6:593-8. [DOI: 10.1016/j.celrep.2014.01.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2013] [Revised: 12/19/2013] [Accepted: 01/17/2014] [Indexed: 11/24/2022] Open
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18
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van den Elzen AMG, Schuller A, Green R, Séraphin B. Dom34-Hbs1 mediated dissociation of inactive 80S ribosomes promotes restart of translation after stress. EMBO J 2014; 33:265-76. [PMID: 24424461 DOI: 10.1002/embj.201386123] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Following translation termination, ribosomal subunits dissociate to become available for subsequent rounds of protein synthesis. In many translation-inhibiting stress conditions, e.g. glucose starvation in yeast, free ribosomal subunits reassociate to form a large pool of non-translating 80S ribosomes stabilized by the 'clamping' Stm1 factor. The subunits of these inactive ribosomes need to be mobilized for translation restart upon stress relief. The Dom34-Hbs1 complex, together with the Rli1 NTPase (also known as ABCE1), have been shown to split ribosomes stuck on mRNAs in the context of RNA quality control mechanisms. Here, using in vitro and in vivo methods, we report a new role for the Dom34-Hbs1 complex and Rli1 in dissociating inactive ribosomes, thereby facilitating translation restart in yeast recovering from glucose starvation stress. Interestingly, we found that this new role is not restricted to stress conditions, indicating that in growing yeast there is a dynamic pool of inactive ribosomes that needs to be split by Dom34-Hbs1 and Rli1 to participate in protein synthesis. We propose that this provides a new level of translation regulation.
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Affiliation(s)
- Antonia M G van den Elzen
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC) Centre National de Recherche Scientifique (CNRS) UMR 7104/Institut National de Santé et de Recherche Médicale (INSERM) U964/Université de Strasbourg, Illkirch, France
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19
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Kolesnikova O, Back R, Graille M, Séraphin B. Identification of the Rps28 binding motif from yeast Edc3 involved in the autoregulatory feedback loop controlling RPS28B mRNA decay. Nucleic Acids Res 2013; 41:9514-23. [PMID: 23956223 PMCID: PMC3814365 DOI: 10.1093/nar/gkt607] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In the yeast Saccharomyces cerevisiae, the Edc3 protein was previously reported to participate in the auto-regulatory feedback loop controlling the level of the RPS28B messenger RNA (mRNA). We show here that Edc3 binds directly and tightly to the globular core of Rps28 ribosomal protein. This binding occurs through a motif that is present exclusively in Edc3 proteins from yeast belonging to the Saccharomycetaceae phylum. Functional analyses indicate that the ability of Edc3 to interact with Rps28 is not required for its general function and for its role in the regulation of the YRA1 pre-mRNA decay. In contrast, this interaction appears to be exclusively required for the auto-regulatory mechanism controlling the RPS28B mRNA decay. These observations suggest a plausible model for the evolutionary appearance of a Rps28 binding motif in Edc3.
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Affiliation(s)
- Olga Kolesnikova
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de la Recherche Scientifique (CNRS) UMR 7104/Institut National de la Santé et de la Recherche Médicale (INSERM) U964/Université de Strasbourg, 67404 Illkirch, France, Ecole Polytechnique, Laboratoire de Biochimie, CNRS UMR7654, 91128 Palaiseau Cedex, France and Institut de Biochimie et Biophysique Moléculaire et Cellulaire (IBBMC), CNRS, UMR8619, Bat 430, Université Paris Sud, 91405 Orsay Cedex, France
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20
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Dreumont N, Séraphin B. Rapid screening of yeast mutants with reporters identifies new splicing phenotypes. FEBS J 2013; 280:2712-26. [PMID: 23560879 DOI: 10.1111/febs.12277] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 04/01/2013] [Accepted: 04/02/2013] [Indexed: 11/29/2022]
Abstract
Nuclear precursor mRNA splicing requires the stepwise assembly of a large complex, the spliceosome. Recent large-scale analyses, including purification of splicing complexes, high-throughput genetic screens and interactomic studies, have linked numerous factors to this dynamic process, including a well-defined core conserved from yeast to human. Intriguingly, despite extensive studies, no splicing defects were reported for some of the corresponding yeast mutants. To resolve this paradox, we screened a collection of viable yeast strains carrying mutations in splicing-related factors with a set of reporters including artificial constructs carrying competing splice sites. Previous analyses have indeed demonstrated that this strategy identifies yeast factors able to regulate alternative splicing and whose properties are conserved in human cells. The method, sensitive to subtle defects, revealed new splicing phenotypes for most analyzed factors such as the Urn1 protein. Interestingly, a mutant of PRP8 specifically lacking an N-terminal proline-rich region stimulated the splicing of a reporter containing competing branchpoint/3' splice site regions. Thus, using appropriate reporters, yeast can be used to quickly delineate the effect of various factors on splicing and identify those with the propensity to regulate alternative splicing events.
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Affiliation(s)
- Natacha Dreumont
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 67404 Illkirch, France
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21
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Abstract
The CCR4-NOT complex was originally identified and its composition and organization characterized in the yeast Saccharomyces cerevisiae. It was first suggested to participate in transcription regulation, but since then it has become clear that it plays a key role in mRNA decay in all eukaryotes, thereby contributing importantly to gene expression regulation. Hence, the mammalian CCR4-NOT complex was recently shown to participate in miRNA-mediated mRNA repression. A better characterization of the composition and organization of this complex in higher eukaryotes is thus warranted. Purifications of the CCR4-NOT complex, performed by others and us, suggest that the protein of unknown function C2ORF29 is associated with this assembly. We demonstrate here that C2ORF29 is indeed a bona fide subunit of the human CCR4-NOT complex and propose to rename it CNOT11. In addition, we show that CNOT11 interacts with the first amino acids of CNOT1 and with CNOT10 and is required for the association of CNOT10 with the CCR4-NOT complex. Thus, the human CCR4-NOT complex possesses in addition to the CCR4-CAF1 deadenylase module and to the NOT module, a module composed of CNOT10 and CNOT11 that interacts with the N-terminal part of CNOT1. Phylogenetic analyses indicate that the CNOT10/CNOT11 module is conserved in all eukaryotes except fungi.
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Affiliation(s)
- Fabienne Mauxion
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire IGBMC, Centre National de Recherche Scientifique CNRS, UMR 7104, Institut National de Santé et de Recherche Médicale INSERM, U964, Université de Strasbourg, Illkirch, France.
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22
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23
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Francis SM, Gas ME, Daugeron MC, Bravo J, Séraphin B. Rbg1-Tma46 dimer structure reveals new functional domains and their role in polysome recruitment. Nucleic Acids Res 2012; 40:11100-14. [PMID: 23002146 PMCID: PMC3510508 DOI: 10.1093/nar/gks867] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Developmentally Regulated GTP-binding (DRG) proteins are highly conserved GTPases that associate with DRG Family Regulatory Proteins (DFRP). The resulting complexes have recently been shown to participate in eukaryotic translation. The structure of the Rbg1 GTPase, a yeast DRG protein, in complex with the C-terminal region of its DFRP partner, Tma46, was solved by X-ray diffraction. These data reveal that DRG proteins are multimodular factors with three additional domains, helix–turn–helix (HTH), S5D2L and TGS, packing against the GTPase platform. Surprisingly, the S5D2L domain is inserted in the middle of the GTPase sequence. In contrast, the region of Tma46 interacting with Rbg1 adopts an extended conformation typical of intrinsically unstructured proteins and contacts the GTPase and TGS domains. Functional analyses demonstrate that the various domains of Rbg1, as well as Tma46, modulate the GTPase activity of Rbg1 and contribute to the function of these proteins in vivo. Dissecting the role of the different domains revealed that the Rbg1 TGS domain is essential for the recruitment of this factor in polysomes, supporting further the implication of these conserved factors in translation.
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Affiliation(s)
- Sandrea M Francis
- Instituto de Biomedicina de Valencia (IBV-CSIC), Calle Jaime Roig, 11, Valencia E-46010, Spain
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Basquin J, Roudko VV, Rode M, Basquin C, Séraphin B, Conti E. Architecture of the nuclease module of the yeast Ccr4-not complex: the Not1-Caf1-Ccr4 interaction. Mol Cell 2012; 48:207-18. [PMID: 22959269 DOI: 10.1016/j.molcel.2012.08.014] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/06/2012] [Accepted: 08/16/2012] [Indexed: 12/23/2022]
Abstract
Shortening eukaryotic poly(A) tails represses mRNA translation and induces mRNA turnover. The major cytoplasmic deadenylase, the Ccr4-Not complex, is a conserved multisubunit assembly. Ccr4-Not is organized around Not1, a large scaffold protein that recruits two 3'-5' exoribonucleases, Caf1 and Ccr4. We report structural studies showing that the N-terminal arm of yeast Not1 has a HEAT-repeat structure with domains related to the MIF4G fold. A MIF4G domain positioned centrally within the Not1 protein recognizes Caf1, which in turn binds the LRR domain of Ccr4 and tethers the Ccr4 nuclease domain. The interactions that form the nuclease core of the Ccr4-Not complex are evolutionarily conserved. Their specific disruption affects cell growth and mRNA deadenylation and decay in vivo in yeast. Thus, the N-terminal arm of Not1 forms an extended platform reminiscent of scaffolding proteins like eIF4G and CBP80, and places the two nucleases in a pivotal position within the Ccr4-Not complex.
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Affiliation(s)
- Jérôme Basquin
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
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Abstract
The conserved multi-subunit Elongator complex was initially described as a RNA polymerase II (RNAPII) associated transcription elongation factor, but since has been shown to be involved a variety of different cellular activities. Here, we summarize recent developments in the field and discuss the resulting implications for the proposed multi-functionality of Elongator.
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Affiliation(s)
- Sebastian Glatt
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
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Glatt S, Létoquart J, Faux C, Taylor NMI, Séraphin B, Müller CW. The Elongator subcomplex Elp456 is a hexameric RecA-like ATPase. Nat Struct Mol Biol 2012; 19:314-20. [PMID: 22343726 DOI: 10.1038/nsmb.2234] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 12/22/2011] [Indexed: 12/23/2022]
Abstract
Elongator was initially described as an RNA polymerase II-associated factor but has since been associated with a broad range of cellular activities. It has also attracted clinical attention because of its role in certain neurodegenerative diseases. Here we describe the crystal structure of the Saccharomyces cerevisiae subcomplex of Elongator proteins 4, 5 and 6 (Elp456). The subunits each show almost identical RecA folds that form a heterohexameric ring-like structure resembling hexameric RecA-like ATPases. This structural finding is supported by different complementary in vitro and in vivo approaches, including the specific binding of the hexameric Elp456 subcomplex to tRNAs in a manner regulated by ATP. Our results support a role of Elongator in tRNA modification, explain the importance of each of the Elp4, Elp5 and Elp6 subunits for complex integrity and suggest a model for the overall architecture of the holo-Elongator complex.
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Affiliation(s)
- Sebastian Glatt
- European Molecular Biology Laboratory (EMBL), Structural and Computational Biology Unit, Heidelberg, Germany
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28
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Görnemann J, Barrandon C, Hujer K, Rutz B, Rigaut G, Kotovic KM, Faux C, Neugebauer KM, Séraphin B. Cotranscriptional spliceosome assembly and splicing are independent of the Prp40p WW domain. RNA 2011; 17:2119-29. [PMID: 22020974 PMCID: PMC3222125 DOI: 10.1261/rna.02646811] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Complex cellular functions involve large networks of interactions. Pre-mRNA splicing and transcription are thought to be coupled by the C-terminal domain (CTD) of the large subunit of RNA polymerase II (Pol II). In yeast, the U1 snRNP subunit Prp40 was proposed to mediate cotranscriptional recruitment of early splicing factors through binding of its WW domains to the Pol II CTD. Here we investigate the role of Prp40 in splicing with an emphasis on the role of the WW domains, which might confer protein-protein interactions among the splicing and transcriptional machineries. Affinity purification revealed that Prp40 and Snu71 form a stable heterodimer that stably associates with the U1 snRNP only in the presence of Nam8, a known regulator of 5' splice site recognition. However, the Prp40 WW domains were dispensable for yeast viability. In their absence, no defect in splicing in vivo, U1 or U2 snRNP recruitment in vivo, or early splicing complex assembly in vitro was detected. We conclude that the WW domains of Prp40 do not mediate essential coupling between U1 snRNP and Pol II. Instead, delays in cotranscriptional U5 snRNP and Prp19 recruitment and altered spliceosome formation in vitro suggest that Prp40 WW domains assist in late steps of spliceosome assembly.
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Affiliation(s)
- Janina Görnemann
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | | | - Katja Hujer
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | | | | | - Kimberly M. Kotovic
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Céline Faux
- CGM, CNRS, 91198 Gif sur Yvette Cedex, France
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de Santé et de Recherche Médicale (INSERM) U964/Centre National de Recherche Scientifique (CNRS) UMR 7104/Université de Strasbourg, 67404 Illkirch, France
| | - Karla M. Neugebauer
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
- Corresponding authors.E-mail E-mail .
| | - Bertrand Séraphin
- CGM, CNRS, 91198 Gif sur Yvette Cedex, France
- EMBL, D-69117 Heidelberg, Germany
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de Santé et de Recherche Médicale (INSERM) U964/Centre National de Recherche Scientifique (CNRS) UMR 7104/Université de Strasbourg, 67404 Illkirch, France
- Corresponding authors.E-mail E-mail .
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Rispal D, Henri J, van Tilbeurgh H, Graille M, Séraphin B. Structural and functional analysis of Nro1/Ett1: a protein involved in translation termination in S. cerevisiae and in O2-mediated gene control in S. pombe. RNA 2011; 17:1213-1224. [PMID: 21610214 PMCID: PMC3138559 DOI: 10.1261/rna.2697111] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 04/01/2011] [Indexed: 05/30/2023]
Abstract
In Saccharomyces cerevisiae, the putative 2-OG-Fe(II) dioxygenase Tpa1 and its partner Ett1 have been shown to impact mRNA decay and translation. Hence, inactivation of these factors was shown to influence stop codon read-though. In addition, Tpa1 represses, by an unknown mechanism, genes regulated by Hap1, a transcription factor involved in the response to levels of heme and O(2). The Schizosaccharomyces pombe orthologs of Tpa1 and Ett1, Ofd1, and its partner Nro1, respectively, have been shown to regulate the stability of the Sre1 transcription factor in response to oxygen levels. To gain insight into the function of Nro1/Ett1, we have solved the crystal structure of the S. pombe Nro1 protein deleted of its 54 N-terminal residues. Nro1 unexpectedly adopts a Tetratrico Peptide Repeat (TPR) fold, a motif often responsible for protein or peptide binding. Two ligands, a sulfate ion and an unknown molecule, interact with a cluster of highly conserved amino acids on the protein surface. Mutation of these residues demonstrates that these ligand binding sites are essential for Ett1 function in S. cerevisiae, as investigated by assaying for efficient translation termination.
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Affiliation(s)
- Delphine Rispal
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR7104, Inserm U964, and Université de Strasbourg, Strasbourg, Illkirch F-67000, France
- Centre de Génétique Moléculaire (CGM), CNRS, F-91198 Gif-sur-Yvette Cedex, France
| | - Julien Henri
- Equipe “Fonction et Architecture des Assemblages Macromoléculaires”, IBBMC (Institut de Biochimie et Biophysique Moléculaire et Cellulaire), CNRS, UMR8619, Bat 430, Université Paris Sud, F-91405 Orsay Cedex, France
| | - Herman van Tilbeurgh
- Equipe “Fonction et Architecture des Assemblages Macromoléculaires”, IBBMC (Institut de Biochimie et Biophysique Moléculaire et Cellulaire), CNRS, UMR8619, Bat 430, Université Paris Sud, F-91405 Orsay Cedex, France
| | - Marc Graille
- Equipe “Fonction et Architecture des Assemblages Macromoléculaires”, IBBMC (Institut de Biochimie et Biophysique Moléculaire et Cellulaire), CNRS, UMR8619, Bat 430, Université Paris Sud, F-91405 Orsay Cedex, France
| | - Bertrand Séraphin
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR7104, Inserm U964, and Université de Strasbourg, Strasbourg, Illkirch F-67000, France
- Centre de Génétique Moléculaire (CGM), CNRS, F-91198 Gif-sur-Yvette Cedex, France
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Collinet B, Friberg A, Brooks MA, van den Elzen T, Henriot V, Dziembowski A, Graille M, Durand D, Leulliot N, Saint André C, Lazar N, Sattler M, Séraphin B, van Tilbeurgh H. Strategies for the structural analysis of multi-protein complexes: lessons from the 3D-Repertoire project. J Struct Biol 2011; 175:147-58. [PMID: 21463689 DOI: 10.1016/j.jsb.2011.03.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 03/18/2011] [Accepted: 03/19/2011] [Indexed: 11/25/2022]
Abstract
Structural studies of multi-protein complexes, whether by X-ray diffraction, scattering, NMR spectroscopy or electron microscopy, require stringent quality control of the component samples. The inability to produce 'keystone' subunits in a soluble and correctly folded form is a serious impediment to the reconstitution of the complexes. Co-expression of the components offers a valuable alternative to the expression of single proteins as a route to obtain sufficient amounts of the sample of interest. Even in cases where milligram-scale quantities of purified complex of interest become available, there is still no guarantee that good quality crystals can be obtained. At this step, protein engineering of one or more components of the complex is frequently required to improve solubility, yield or the ability to crystallize the sample. Subsequent characterization of these constructs may be performed by solution techniques such as Small Angle X-ray Scattering and Nuclear Magnetic Resonance to identify 'well behaved' complexes. Herein, we recount our experiences gained at protein production and complex assembly during the European 3D Repertoire project (3DR). The goal of this consortium was to obtain structural information on multi-protein complexes from yeast by combining crystallography, electron microscopy, NMR and in silico modeling methods. We present here representative set case studies of complexes that were produced and analyzed within the 3DR project. Our experience provides useful insight into strategies that are more generally applicable for structural analysis of protein complexes.
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Affiliation(s)
- B Collinet
- IBBMC-CNRS UMR8619, IFR 115, Bât. 430, Université Paris-Sud, 91405 Orsay, France
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31
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Brooks MA, Gewartowski K, Mitsiki E, Létoquart J, Pache RA, Billier Y, Bertero M, Corréa M, Czarnocki-Cieciura M, Dadlez M, Henriot V, Lazar N, Delbos L, Lebert D, Piwowarski J, Rochaix P, Böttcher B, Serrano L, Séraphin B, van Tilbeurgh H, Aloy P, Perrakis A, Dziembowski A. Systematic bioinformatics and experimental validation of yeast complexes reduces the rate of attrition during structural investigations. Structure 2011; 18:1075-82. [PMID: 20826334 DOI: 10.1016/j.str.2010.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2010] [Revised: 06/30/2010] [Accepted: 08/07/2010] [Indexed: 10/19/2022]
Abstract
For high-throughput structural studies of protein complexes of composition inferred from proteomics data, it is crucial that candidate complexes are selected accurately. Herein, we exemplify a procedure that combines a bioinformatics tool for complex selection with in vivo validation, to deliver structural results in a medium-throughout manner. We have selected a set of 20 yeast complexes, which were predicted to be feasible by either an automated bioinformatics algorithm, by manual inspection of primary data, or by literature searches. These complexes were validated with two straightforward and efficient biochemical assays, and heterologous expression technologies of complex components were then used to produce the complexes to assess their feasibility experimentally. Approximately one-half of the selected complexes were useful for structural studies, and we detail one particular success story. Our results underscore the importance of accurate target selection and validation in avoiding transient, unstable, or simply nonexistent complexes from the outset.
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Affiliation(s)
- Mark A Brooks
- IBBMC-CNRS UMR8619, IFR 115, Bât. 430, Université Paris-Sud, 91405 Orsay, France
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Daugeron MC, Prouteau M, Lacroute F, Séraphin B. The highly conserved eukaryotic DRG factors are required for efficient translation in a manner redundant with the putative RNA helicase Slh1. Nucleic Acids Res 2010; 39:2221-33. [PMID: 21076151 PMCID: PMC3064805 DOI: 10.1093/nar/gkq898] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Eukaryotic and archaeal DRG factors are highly conserved proteins with characteristic GTPase motifs. This suggests their implication in a central biological process, which has so far escaped detection. We show here that the two Saccharomyces cerevisiae DRGs form distinct complexes, RBG1 and RBG2, and that the former co-fractionate with translating ribosomes. A genetic screen for triple synthetic interaction demonstrates that yeast DRGs have redundant function with Slh1, a putative RNA helicase also associating with translating ribosomes. Translation and cell growth are severely impaired in a triple mutant lacking both yeast DRGs and Slh1, but not in double mutants. This new genetic assay allowed us to characterize the roles of conserved motifs present in these proteins for efficient translation and/or association with ribosomes. Altogether, our results demonstrate for the first time a direct role of the highly conserved DRG factors in translation and indicate that this function is redundantly shared by three factors. Furthermore, our data suggest that important cellular processes are highly buffered against external perturbation and, consequently, that redundantly acting factors may escape detection in current high-throughput binary genetic interaction screens.
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Affiliation(s)
- Marie-Claire Daugeron
- Equipe Labellisée La Ligue, CGM, CNRS FRE3144, 1 Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, Univ Paris-Sud, Orsay F-91405, France
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33
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Affiliation(s)
- María-Eugenia Gas
- Equipe Labellisée La Ligue, IGMBC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France
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34
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Henri J, Rispal D, Bayart E, van Tilbeurgh H, Séraphin B, Graille M. Structural and functional insights into Saccharomyces cerevisiae Tpa1, a putative prolylhydroxylase influencing translation termination and transcription. J Biol Chem 2010; 285:30767-78. [PMID: 20630870 DOI: 10.1074/jbc.m110.106864] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Efficiency of translation termination relies on the specific recognition of the three stop codons by the eukaryotic translation termination factor eRF1. To date only a few proteins are known to be involved in translation termination in eukaryotes. Saccharomyces cerevisiae Tpa1, a largely conserved but uncharacterized protein, has been described to associate with a messenger ribonucleoprotein complex located at the 3' end of mRNAs that contains at least eRF1, eRF3, and Pab1. Deletion of the TPA1 gene results in a decrease of translation termination efficacy and an increase in mRNAs half-lives and longer mRNA poly(A) tails. In parallel, Schizosaccharomyces pombe Ofd1, a Tpa1 ortholog, and its partner Nro1 have been implicated in the regulation of the stability of a transcription factor that regulates genes essential for the cell response to hypoxia. To gain insight into Tpa1/Ofd1 function, we have solved the crystal structure of S. cerevisiae Tpa1 protein. This protein is composed of two equivalent domains with the double-stranded β-helix fold. The N-terminal domain displays a highly conserved active site with strong similarities with prolyl-4-hydroxylases. Further functional studies show that the integrity of Tpa1 active site as well as the presence of Yor051c/Ett1 (the S. cerevisiae Nro1 ortholog) are essential for correct translation termination. In parallel, we show that Tpa1 represses the expression of genes regulated by Hap1, a transcription factor involved in the response to levels of heme and oxygen. Altogether, our results support that Tpa1 is a putative enzyme acting as an oxygen sensor and influencing several distinct regulatory pathways.
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Affiliation(s)
- Julien Henri
- Institut de Biochimie et Biophysique Moléculaire et Cellulaire, CNRS UMR8619 Bat 430 Université Paris Sud, 91405 Orsay Cedex, France
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Chlebowski A, Tomecki R, López MEG, Séraphin B, Dziembowski A. Catalytic properties of the eukaryotic exosome. Adv Exp Med Biol 2010; 702:63-78. [PMID: 21618875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The eukaryotic exosome complex is built around the backbone of a 9-subunit ring similar to phosporolytic ribonucleases such as RNase PH and polynucleotide phosphorylase (PNPase). Unlike those enzymes, the ring is devoid of any detectable catalytic activities, with the possible exception of the plant version of the complex. Instead, the essential RNA decay capability is supplied by associated hydrolytic ribonucleases belonging to the Dis3 and Rrp6 families. Dis3 proteins are endowed with two different activities: the long known processive 3'-5' exonucleolytic one and the recently discovered endonucleolytic one. Rrp6 proteins are distributive exonucleases. This chapter will review the current knowledge about the catalytic properties of theses nucleases and their interplay within the exosome holocomplex.
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Affiliation(s)
- Aleksander Chlebowski
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, and Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
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Mauxion F, Chen CYA, Séraphin B, Shyu AB. BTG/TOB factors impact deadenylases. Trends Biochem Sci 2009; 34:640-7. [PMID: 19828319 DOI: 10.1016/j.tibs.2009.07.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 07/19/2009] [Accepted: 07/21/2009] [Indexed: 10/20/2022]
Abstract
BTG/TOB factors are a family of antiproliferative proteins whose expression is altered in numerous cancers. They have been implicated in cell differentiation, development and apoptosis. Although proposed to affect transcriptional regulation, these factors interact with CAF1, a subunit of the main eukaryotic deadenylase, and with poly(A)-binding-proteins, strongly suggesting a role in post-transcriptional regulation of gene expression. The recent determination of the structures of BTG2, TOB1 N-terminal domain (TOB1N138) and TOB1N138-CAF1 complexes support a role for BTG/TOB proteins in mRNA deadenylation, a function corroborated by recently published functional characterizations. We highlight molecular mechanisms by which BTG/TOB proteins influence deadenylation and discuss the need for a better understanding of BTG/TOB physiological functions.
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Affiliation(s)
- Fabienne Mauxion
- Equipe Labellisée La Ligue, Centre de Génétique Moléculaire, CNRS FRE3144, Gif-sur-Yvette, France
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37
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Lebreton A, Tomecki R, Dziembowski A, Séraphin B. Endonucleolytic RNA cleavage by a eukaryotic exosome. Nature 2008; 456:993-6. [PMID: 19060886 DOI: 10.1038/nature07480] [Citation(s) in RCA: 260] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Accepted: 09/25/2008] [Indexed: 11/09/2022]
Abstract
The exosome is a major eukaryotic nuclease located in both the nucleus and the cytoplasm that contributes to the processing, quality control and/or turnover of a large number of cellular RNAs. This large macromolecular assembly has been described as a 3'-->5' exonuclease and shown to contain a nine-subunit ring structure evolutionarily related to archaeal exosome-like complexes and bacterial polynucleotide phosphorylases. Recent results have shown that, unlike its prokaryotic counterparts, the yeast and human ring structures are catalytically inactive. In contrast, the exonucleolytic activity of the yeast exosome core was shown to be mediated by the RNB domain of the eukaryote-specific Dis3 subunit. Here we show, using in vitro assays, that yeast Dis3 has an additional endoribonuclease activity mediated by the PIN domain located at the amino terminus of this multidomain protein. Simultaneous inactivation of the endonucleolytic and exonucleolytic activities of the exosome core generates a synthetic growth phenotype in vivo, supporting a physiological function for the PIN domain. This activity is responsible for the cleavage of some natural exosome substrates, independently of exonucleolytic degradation. In contrast with current models, our results show that eukaryotic exosome cores have both endonucleolytic and exonucleolytic activities, mediated by two distinct domains of the Dis3 subunit. The mode of action of eukaryotic exosome cores in RNA processing and degradation should be reconsidered, taking into account the cooperation between its multiple ribonucleolytic activities.
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Affiliation(s)
- Alice Lebreton
- Equipe Labellisée La Ligue, Centre de Génétique Moléculaire, CNRS UPR 2167, 91198 Gif-sur-Yvette, France
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38
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Brooks MA, Dziembowski A, Quevillon-Cheruel S, Henriot V, Faux C, van Tilbeurgh H, Séraphin B. Structure of the yeast Pml1 splicing factor and its integration into the RES complex. Nucleic Acids Res 2008; 37:129-43. [PMID: 19033360 PMCID: PMC2615620 DOI: 10.1093/nar/gkn894] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The RES complex was previously identified in yeast as a splicing factor affecting nuclear pre-mRNA retention. This complex was shown to contain three subunits, namely Snu17, Bud13 and Pml1, but its mode of action remains ill-defined. To obtain insights into its function, we have performed a structural investigation of this factor. Production of a short N-terminal truncation of residues that are apparently disordered allowed us to determine the X-ray crystallographic structure of Pml1. This demonstrated that it consists mainly of a FHA domain, a fold which has been shown to mediate interactions with phosphothreonine-containing peptides. Using a new sensitive assay based on alternative splice-site choice, we show, however, that mutation of the putative phosphothreonine-binding pocket of Pml1 does not affect pre-mRNA splicing. We have also investigated how Pml1 integrates into the RES complex. Production of recombinant complexes, combined with serial truncation and mutagenesis of their subunits, indicated that Pml1 binds to Snu17, which itself contacts Bud13. This analysis allowed us to demarcate the binding sites involved in the formation of this assembly. We propose a model of the organization of the RES complex based on these results, and discuss the functional consequences of this architecture.
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Affiliation(s)
- Mark A. Brooks
- IBBMC-CNRS UMR8619, IFR 115, Bât. 430, Université Paris-Sud, 91405 Orsay, Equipe Labelisée La Ligue, CGM, CNRS UPR2167, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, Univ Paris-Sud, Orsay, F-91405 and Université Pierre et Marie Curie- Paris 6, Paris, F-75005, France
| | - Andrzej Dziembowski
- IBBMC-CNRS UMR8619, IFR 115, Bât. 430, Université Paris-Sud, 91405 Orsay, Equipe Labelisée La Ligue, CGM, CNRS UPR2167, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, Univ Paris-Sud, Orsay, F-91405 and Université Pierre et Marie Curie- Paris 6, Paris, F-75005, France
| | - Sophie Quevillon-Cheruel
- IBBMC-CNRS UMR8619, IFR 115, Bât. 430, Université Paris-Sud, 91405 Orsay, Equipe Labelisée La Ligue, CGM, CNRS UPR2167, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, Univ Paris-Sud, Orsay, F-91405 and Université Pierre et Marie Curie- Paris 6, Paris, F-75005, France
| | - Véronique Henriot
- IBBMC-CNRS UMR8619, IFR 115, Bât. 430, Université Paris-Sud, 91405 Orsay, Equipe Labelisée La Ligue, CGM, CNRS UPR2167, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, Univ Paris-Sud, Orsay, F-91405 and Université Pierre et Marie Curie- Paris 6, Paris, F-75005, France
| | - Céline Faux
- IBBMC-CNRS UMR8619, IFR 115, Bât. 430, Université Paris-Sud, 91405 Orsay, Equipe Labelisée La Ligue, CGM, CNRS UPR2167, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, Univ Paris-Sud, Orsay, F-91405 and Université Pierre et Marie Curie- Paris 6, Paris, F-75005, France
| | - Herman van Tilbeurgh
- IBBMC-CNRS UMR8619, IFR 115, Bât. 430, Université Paris-Sud, 91405 Orsay, Equipe Labelisée La Ligue, CGM, CNRS UPR2167, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, Univ Paris-Sud, Orsay, F-91405 and Université Pierre et Marie Curie- Paris 6, Paris, F-75005, France
| | - Bertrand Séraphin
- IBBMC-CNRS UMR8619, IFR 115, Bât. 430, Université Paris-Sud, 91405 Orsay, Equipe Labelisée La Ligue, CGM, CNRS UPR2167, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, Univ Paris-Sud, Orsay, F-91405 and Université Pierre et Marie Curie- Paris 6, Paris, F-75005, France
- *To whom correspondence should be addressed. Tel: + 33 1 69 82 38 84; Fax: + 33 1 69 82 38 77;
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Prouteau M, Daugeron MC, Séraphin B. Regulation of ARE transcript 3' end processing by the yeast Cth2 mRNA decay factor. EMBO J 2008; 27:2966-76. [PMID: 18923425 DOI: 10.1038/emboj.2008.212] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Accepted: 09/12/2008] [Indexed: 11/09/2022] Open
Abstract
Regulation of mRNA decay is an important step modulating gene expression. The stability of numerous eukaryotic mRNAs is controlled by adenosine/uridine-rich elements (AREs) located in their 3'UTR. In Saccharomyces cerevisiae, the Cth2 protein stimulates the decay of target ARE mRNAs on iron starvation. Cth2, and its mammalian homologue tristetraprolin, contains a characteristic tandem CCCH zinc-finger essential for ARE binding and mRNA decay. We have performed a structure-function analysis of Cth2 to understand the mechanism(s) by which it destabilizes mRNAs. This indicated that a conserved N-terminal region of Cth2 is essential for its decay function but dispensable for RNA binding. Unexpectedly, Cth2 mutants lacking this domain blocked the normal 3' end processing of ARE mRNAs leading to the formation of extended transcripts. These can also be detected in mutant of the polyadenylation machinery. Consistently, Cth2 localization in the nucleus suggests that it may interfere with poly(A) site selection. Our analysis reveal that ARE-binding protein may affect mRNA 3' end processing and that this contributes to mRNA destabilization.
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Affiliation(s)
- Manoël Prouteau
- Equipe Labellisée La Ligue, CNRS, Centre de Génétique Moléculaire, UPR 2167, Gif-sur-Yvette, France
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Thiebaut M, Colin J, Neil H, Jacquier A, Séraphin B, Lacroute F, Libri D. Futile cycle of transcription initiation and termination modulates the response to nucleotide shortage in S. cerevisiae. Mol Cell 2008; 31:671-82. [PMID: 18775327 DOI: 10.1016/j.molcel.2008.08.010] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2008] [Revised: 06/04/2008] [Accepted: 08/12/2008] [Indexed: 10/21/2022]
Abstract
Hidden transcription in eukaryotes carries a large potential of regulatory functions that are only recently beginning to emerge. Cryptic unstable transcripts (CUTs) are generated by RNA polymerase II (Pol II) and rapidly degraded after transcription in wild-type yeast cells. Whether CUTs or the act of transcription without RNA production have a function is presently unclear. We describe here a nonconventional mechanism of transcriptional regulation that relies on the selection of alternative transcription start sites to generate CUTs or mRNAs. Transcription from TATA box proximal start sites generates unstable transcripts and downregulates expression of the URA2 gene under repressing conditions. Uracil deprivation activates selection of distal start sites, leading to the production of stable mRNAs. We describe the elements that govern degradation of the CUT and activation of mRNA production by downstream transcription initiation. Importantly, we show that a similar mechanism applies to other genes in the nucleotides biogenesis pathway.
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Affiliation(s)
- Marilyne Thiebaut
- LEA Laboratory of Nuclear RNA Metabolism, Centre de Génétique Moléculaire, CNRS, UPR2167, 1, av de la Terrasse, 91190, Gif sur Yvette, France
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Abstract
In mammalian cells, the splicing machinery deposits the exon junction complex (EJC) on mRNA splice junctions. Two studies in this issue now link the EJC to different aspects of translational control. Ma et al. (2008) show that the EJC activates translation downstream of the mTOR signaling pathway, whereas Isken et al. (2008) establish that translation is repressed by partners of the EJC that are implicated in nonsense mediated decay (NMD).
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Affiliation(s)
- Hervé Le Hir
- Equipe Labelisée La Ligue, Centre de Génétique Moléculaire, CNRS UPR 2167, 91198 Gif-sur-Yvette, France
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Mauxion F, Faux C, Séraphin B. The BTG2 protein is a general activator of mRNA deadenylation. EMBO J 2008; 27:1039-48. [PMID: 18337750 DOI: 10.1038/emboj.2008.43] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Accepted: 02/18/2008] [Indexed: 12/11/2022] Open
Abstract
BTG2 is a prototype member of the BTG/Tob family of antiproliferative proteins, originally identified as a primary response gene induced by growth factors and tumour promoters. Its expression has been linked to diverse cellular processes such as cell-cycle progression, differentiation or apoptosis. BTG2 has also been shown to interact with the Pop2/Caf1 deadenylase. Here, we demonstrate that BTG2 is a general activator of mRNA decay, thereby contributing to gene expression control. Detailed characterizations of BTG2 show that it enhances deadenylation of all transcripts tested. Our results demonstrate that Caf1 nuclease activity is required for efficient deadenylation in mammalian cells and that the deadenylase activities of both Caf1 and its Ccr4 partner are required for Btg2-induced poly(A) degradation. General activation of deadenylation may represent a new mode of global regulation of gene expression, which could be important to allow rapid resetting of protein production during development or after specific stresses. This may constitute a common function for BTG/Tob family members.
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Affiliation(s)
- Fabienne Mauxion
- CNRS, Equipe Labellisée La Ligue, Centre de Génétique Moléculaire, UPR 2167, Gif-sur-Yvette, France.
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Lebreton A, Séraphin B. Exosome-mediated quality control: substrate recruitment and molecular activity. Biochim Biophys Acta 2008; 1779:558-65. [PMID: 18313413 DOI: 10.1016/j.bbagrm.2008.02.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Accepted: 02/05/2008] [Indexed: 10/22/2022]
Abstract
The eukaryotic exosome is a multisubunit complex that is mainly responsible for 3'-5' exonucleolytic degradation of RNAs, both in the nucleus and the cytoplasm. In this review we summarize the recent experiments that have provided information on the organisation, structure and activity of this large assembly. Interestingly, eukaryotic exosomes have been implicated in a large number of RNA degradation pathways including recently discovered RNA quality control mechanisms. A variety of cofactors have been shown to participate in substrate recruitment and/or assist exonucleolytic activities. Despite this avalanche of new results, further analyses will be required to improve our understanding of exosome regulation.
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Affiliation(s)
- Alice Lebreton
- Equipe Labellisée La Ligue, Centre de Génétique Moléculaire, CNRS UPR2167 Associée à l'Université P. et M. Curie, Avenue de la Terrasse, 91198 Gif sur Yvette, France
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Kuwasako K, Dohmae N, Inoue M, Shirouzu M, Taguchi S, Güntert P, Séraphin B, Muto Y, Yokoyama S. Complex assembly mechanism and an RNA-binding mode of the human p14-SF3b155 spliceosomal protein complex identified by NMR solution structure and functional analyses. Proteins 2007; 71:1617-36. [DOI: 10.1002/prot.21839] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Abstract
mRNA poly(A) tails affect translation, mRNA export and mRNA stability, with translation initiation involving a direct interaction between eIF4G and the poly(A)-binding protein Pab1. The latter factor contains four RNA recognition motifs followed by a C-terminal region composed of a linker and a PABC domain. We show here that yeast mutants lacking the C-terminal domains of Pab1 display specific synthetic interactions with mutants in the 5′-3′ mRNA decay pathway. Moreover, these mutations impair mRNA decay in vivo without significantly affecting mRNA export or translation. Inhibition of mRNA decay occurs through slowed deadenylation. In vitro analyses demonstrate that removal of the Pab1 linker domain directly interferes with the ability of the Pop2–Ccr4 complex to deadenylate the Pab1-bound poly(A). Binding assays demonstrate that this results from a modulation of poly(A) packaging by the Pab1 linker region. Overall, our results demonstrate a direct involvement of Pab1 in mRNA decay and reveal the modular nature of this factor, with different domains affecting various cellular processes. These data suggest new models involving the modulation of poly(A) packaging by Pab1 to control mRNA decay.
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Affiliation(s)
| | - Bertrand Séraphin
- *To whom correspondence should be addressed. +33 1 69 82 38 84+33 1 69 82 38 77
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Puig O, Bragado-Nilsson E, Koski T, Séraphin B. The U1 snRNP-associated factor Luc7p affects 5' splice site selection in yeast and human. Nucleic Acids Res 2007; 35:5874-85. [PMID: 17726058 PMCID: PMC2034479 DOI: 10.1093/nar/gkm505] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
yLuc7p is an essential subunit of the yeast U1 snRNP and contains two putative zinc fingers. Using RNA-protein cross-linking and directed site-specific proteolysis (DSSP), we have established that the N-terminal zinc finger of yLuc7p contacts the pre-mRNA in the 5' exon in a region close to the cap. Modifying the pre-mRNA sequence in the region contacted by yLuc7p affects splicing in a yLuc7p-dependent manner indicating that yLuc7p stabilizes U1 snRNP-pre-mRNA interaction, thus reminding of the mode of action of another U1 snRNP component, Nam8p. Database searches identified three putative human yLuc7p homologs (hLuc7A, hLuc7B1 and hLuc7B2). These proteins have an extended C-terminal tail rich in RS and RE residues, a feature characteristic of splicing factors. Consistent with a role in pre-mRNA splicing, hLuc7A localizes in the nucleus and antibodies raised against hLuc7A specifically co-precipitate U1 snRNA from human cell extracts. Interestingly, hLuc7A overexpression affects splicing of a reporter in vivo. Taken together, our data suggest that the formation of a wide network of protein-RNA interactions around the 5' splice site by U1 snRNP-associated factors contributes to alternative splicing regulation.
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Affiliation(s)
- Oscar Puig
- European Molecular Biology Laboratory, Meyerhofstrasse, 1, 69117 Heidelberg, Germany, Institute of Biotechnology, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland and CGM, CNRS, Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
- *To whom correspondence should be addressed. +358 9191 59423+358 9191 59366 Correspondence may also be addressed to Bertrand Séraphin. +33 1 69 82 38 84+33 1 69 82 38 77
| | - Elisabeth Bragado-Nilsson
- European Molecular Biology Laboratory, Meyerhofstrasse, 1, 69117 Heidelberg, Germany, Institute of Biotechnology, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland and CGM, CNRS, Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
| | - Terhi Koski
- European Molecular Biology Laboratory, Meyerhofstrasse, 1, 69117 Heidelberg, Germany, Institute of Biotechnology, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland and CGM, CNRS, Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
| | - Bertrand Séraphin
- European Molecular Biology Laboratory, Meyerhofstrasse, 1, 69117 Heidelberg, Germany, Institute of Biotechnology, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland and CGM, CNRS, Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
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Buchet-Poyau K, Courchet J, Hir HL, Séraphin B, Scoazec JY, Duret L, Domon-Dell C, Freund JN, Billaud M. Identification and characterization of human Mex-3 proteins, a novel family of evolutionarily conserved RNA-binding proteins differentially localized to processing bodies. Nucleic Acids Res 2007; 35:1289-300. [PMID: 17267406 PMCID: PMC1851655 DOI: 10.1093/nar/gkm016] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In Caenorhabditis elegans, the Mex-3 protein is a translational regulator that specifies the posterior blastomere identity in the early embryo and contributes to the maintenance of the germline totipotency. We have now identified a family of four homologous human Mex-3 genes, called hMex-3A to -3D that encode proteins containing two heterogeneous nuclear ribonucleoprotein K homology (KH) domains and one carboxy-terminal RING finger module. The hMex-3 are phosphoproteins that bind RNA through their KH domains and shuttle between the nucleus and the cytoplasm via the CRM1-dependent export pathway. Our analysis further revealed that hMex-3A and hMex-3B, but not hMex-3C, colocalize with both the hDcp1a decapping factor and Argonaute (Ago) proteins in processing bodies (P bodies), recently characterized as centers of mRNA turnover. Taken together, these findings indicate that hMex-3 proteins constitute a novel family of evolutionarily conserved RNA-binding proteins, differentially recruited to P bodies and potentially involved in post-transcriptional regulatory mechanisms.
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Affiliation(s)
- Karine Buchet-Poyau
- Université de Lyon, Lyon, F-69003, France; université Lyon 1, Domaine Rockefeller, Lyon, F-69003, France; CNRS UMR 5201, Laboratoire de Génétique Moléculaire, Signalisation et Cancer, Lyon, F-69003, France, CNRS UPR 2167, 6 avenue de la Terrasse, 91198 Gif sur Yvette, France, Service Central d’Anatomie et Cytologie Pathologiques, Hôpital Edouard Herriot, 69437 Lyon, France, CNRS UMR 5558, 16 rue Dubois, 69622 Villeurbanne Cedex, France and INSERM U682, 3 avenue Molière, 67200 Strasbourg, France
| | - Julien Courchet
- Université de Lyon, Lyon, F-69003, France; université Lyon 1, Domaine Rockefeller, Lyon, F-69003, France; CNRS UMR 5201, Laboratoire de Génétique Moléculaire, Signalisation et Cancer, Lyon, F-69003, France, CNRS UPR 2167, 6 avenue de la Terrasse, 91198 Gif sur Yvette, France, Service Central d’Anatomie et Cytologie Pathologiques, Hôpital Edouard Herriot, 69437 Lyon, France, CNRS UMR 5558, 16 rue Dubois, 69622 Villeurbanne Cedex, France and INSERM U682, 3 avenue Molière, 67200 Strasbourg, France
| | - Hervé Le Hir
- Université de Lyon, Lyon, F-69003, France; université Lyon 1, Domaine Rockefeller, Lyon, F-69003, France; CNRS UMR 5201, Laboratoire de Génétique Moléculaire, Signalisation et Cancer, Lyon, F-69003, France, CNRS UPR 2167, 6 avenue de la Terrasse, 91198 Gif sur Yvette, France, Service Central d’Anatomie et Cytologie Pathologiques, Hôpital Edouard Herriot, 69437 Lyon, France, CNRS UMR 5558, 16 rue Dubois, 69622 Villeurbanne Cedex, France and INSERM U682, 3 avenue Molière, 67200 Strasbourg, France
| | - Bertrand Séraphin
- Université de Lyon, Lyon, F-69003, France; université Lyon 1, Domaine Rockefeller, Lyon, F-69003, France; CNRS UMR 5201, Laboratoire de Génétique Moléculaire, Signalisation et Cancer, Lyon, F-69003, France, CNRS UPR 2167, 6 avenue de la Terrasse, 91198 Gif sur Yvette, France, Service Central d’Anatomie et Cytologie Pathologiques, Hôpital Edouard Herriot, 69437 Lyon, France, CNRS UMR 5558, 16 rue Dubois, 69622 Villeurbanne Cedex, France and INSERM U682, 3 avenue Molière, 67200 Strasbourg, France
| | - Jean-Yves Scoazec
- Université de Lyon, Lyon, F-69003, France; université Lyon 1, Domaine Rockefeller, Lyon, F-69003, France; CNRS UMR 5201, Laboratoire de Génétique Moléculaire, Signalisation et Cancer, Lyon, F-69003, France, CNRS UPR 2167, 6 avenue de la Terrasse, 91198 Gif sur Yvette, France, Service Central d’Anatomie et Cytologie Pathologiques, Hôpital Edouard Herriot, 69437 Lyon, France, CNRS UMR 5558, 16 rue Dubois, 69622 Villeurbanne Cedex, France and INSERM U682, 3 avenue Molière, 67200 Strasbourg, France
| | - Laurent Duret
- Université de Lyon, Lyon, F-69003, France; université Lyon 1, Domaine Rockefeller, Lyon, F-69003, France; CNRS UMR 5201, Laboratoire de Génétique Moléculaire, Signalisation et Cancer, Lyon, F-69003, France, CNRS UPR 2167, 6 avenue de la Terrasse, 91198 Gif sur Yvette, France, Service Central d’Anatomie et Cytologie Pathologiques, Hôpital Edouard Herriot, 69437 Lyon, France, CNRS UMR 5558, 16 rue Dubois, 69622 Villeurbanne Cedex, France and INSERM U682, 3 avenue Molière, 67200 Strasbourg, France
| | - Claire Domon-Dell
- Université de Lyon, Lyon, F-69003, France; université Lyon 1, Domaine Rockefeller, Lyon, F-69003, France; CNRS UMR 5201, Laboratoire de Génétique Moléculaire, Signalisation et Cancer, Lyon, F-69003, France, CNRS UPR 2167, 6 avenue de la Terrasse, 91198 Gif sur Yvette, France, Service Central d’Anatomie et Cytologie Pathologiques, Hôpital Edouard Herriot, 69437 Lyon, France, CNRS UMR 5558, 16 rue Dubois, 69622 Villeurbanne Cedex, France and INSERM U682, 3 avenue Molière, 67200 Strasbourg, France
| | - Jean-Noël Freund
- Université de Lyon, Lyon, F-69003, France; université Lyon 1, Domaine Rockefeller, Lyon, F-69003, France; CNRS UMR 5201, Laboratoire de Génétique Moléculaire, Signalisation et Cancer, Lyon, F-69003, France, CNRS UPR 2167, 6 avenue de la Terrasse, 91198 Gif sur Yvette, France, Service Central d’Anatomie et Cytologie Pathologiques, Hôpital Edouard Herriot, 69437 Lyon, France, CNRS UMR 5558, 16 rue Dubois, 69622 Villeurbanne Cedex, France and INSERM U682, 3 avenue Molière, 67200 Strasbourg, France
| | - Marc Billaud
- Université de Lyon, Lyon, F-69003, France; université Lyon 1, Domaine Rockefeller, Lyon, F-69003, France; CNRS UMR 5201, Laboratoire de Génétique Moléculaire, Signalisation et Cancer, Lyon, F-69003, France, CNRS UPR 2167, 6 avenue de la Terrasse, 91198 Gif sur Yvette, France, Service Central d’Anatomie et Cytologie Pathologiques, Hôpital Edouard Herriot, 69437 Lyon, France, CNRS UMR 5558, 16 rue Dubois, 69622 Villeurbanne Cedex, France and INSERM U682, 3 avenue Molière, 67200 Strasbourg, France
- *To whom correspondence should be addressed. Tel: (+33) 478 77 72 14; Fax: (+33) 478 77 72 20; E-mail:
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Dziembowski A, Lorentzen E, Conti E, Séraphin B. A single subunit, Dis3, is essentially responsible for yeast exosome core activity. Nat Struct Mol Biol 2006; 14:15-22. [PMID: 17173052 DOI: 10.1038/nsmb1184] [Citation(s) in RCA: 349] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Accepted: 11/28/2006] [Indexed: 11/09/2022]
Abstract
The conserved core of the exosome, the major eukaryotic 3' --> 5' exonuclease, contains nine subunits that form a ring similar to the phosphorolytic bacterial PNPase and archaeal exosome, as well as Dis3. Dis3 is homologous to bacterial RNase II, a hydrolytic enzyme. Previous studies have suggested that all subunits are active 3' --> 5' exoRNases. We show here that Dis3 is responsible for exosome core activity. The purified exosome core has a hydrolytic, processive and Mg(2+)-dependent activity with characteristics similar to those of recombinant Dis3. Moreover, a catalytically inactive Dis3 mutant has no exosome core activity in vitro and shows in vivo RNA degradation phenotypes similar to those resulting from exosome depletion. In contrast, mutations in Rrp41, the only subunit carrying a conserved phosphorolytic site, appear phenotypically not different from wild-type yeast. We observed that the yeast exosome ring mediates interactions with protein partners, providing an explanation for its essential function.
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Affiliation(s)
- Andrzej Dziembowski
- Equipe labellisée La Ligue, Centre de Genetique Moleculaire, Centre National de la Recherche Scientifique UPR2167, associée à l'Université Pierre et Marie Curie, Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France.
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Finoux AL, Séraphin B. In Vivo Targeting of the Yeast Pop2 Deadenylase Subunit to Reporter Transcripts Induces Their Rapid Degradation and Generates New Decay Intermediates. J Biol Chem 2006; 281:25940-7. [PMID: 16793769 DOI: 10.1074/jbc.m600132200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Deadenylation is the rate-limiting step of mRNA decay, yet little is known about the mechanism regulating this process. In yeast, deadenylation is mainly mediated by the Pop2-Ccr4 complex. We tested whether the selective recruitment of this deadenylase to target mRNAs was sufficient to stimulate their decay in vivo. For this purpose, the Pop2 factor was fused to a U1A RNA binding domain while U1A binding sites were inserted in untranslated regions of a reporter transcript. Analysis of the reporter fate in strains expressing the Pop2-U1A-RBD fusion demonstrated a specific activation of target mRNA decay. Increased mRNA degradation involved accumulation of deadenylated mRNAs that was not detected when the control factors Dcp2 or Pub1 were tethered to the same transcript. The rapid target mRNA degradation was also accompanied by the appearance of new decay intermediates generated by the 3' -5' trimming of the corresponding 3' -untranslated region. Interestingly, this process was not mediated by the exosome but may result from the activity of the Pop2-Ccr4 deadenylase itself. These results indicate that selective recruitment of the Pop2-Ccr4 deadenylase is sufficient to activate mRNA decay, even though this process can also be stimulated by additional mechanisms. Furthermore, deadenylase recruitment affects the downstream path of mRNA decay.
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Affiliation(s)
- Anne-Laure Finoux
- Equipe Labelisée La Ligue, Centre de Génétique Moléculaire, CNRS Unite Propre de Recherche 2167 Associée à l'Université P. et M. Curie, Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
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