101
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Insight into the RNA Exosome Complex Through Modeling Pontocerebellar Hypoplasia Type 1b Disease Mutations in Yeast. Genetics 2016; 205:221-237. [PMID: 27777260 DOI: 10.1534/genetics.116.195917] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 10/19/2016] [Indexed: 11/18/2022] Open
Abstract
Pontocerebellar hypoplasia type 1b (PCH1b) is an autosomal recessive disorder that causes cerebellar hypoplasia and spinal motor neuron degeneration, leading to mortality in early childhood. PCH1b is caused by mutations in the RNA exosome subunit gene, EXOSC3 The RNA exosome is an evolutionarily conserved complex, consisting of nine different core subunits, and one or two 3'-5' exoribonuclease subunits, that mediates several RNA degradation and processing steps. The goal of this study is to assess the functional consequences of the amino acid substitutions that have been identified in EXOSC3 in PCH1b patients. To analyze these EXOSC3 substitutions, we generated the corresponding amino acid substitutions in the Saccharomyces cerevisiae ortholog of EXOSC3, Rrp40 We find that the rrp40 variants corresponding to EXOSC3-G31A and -D132A do not affect yeast function when expressed as the sole copy of the essential Rrp40 protein. In contrast, the rrp40-W195R variant, corresponding to EXOSC3-W238R in PCH1b patients, impacts cell growth and RNA exosome function when expressed as the sole copy of Rrp40 The rrp40-W195R protein is unstable, and does not associate efficiently with the RNA exosome in cells that also express wild-type Rrp40 Consistent with these findings in yeast, the levels of mouse EXOSC3 variants are reduced compared to wild-type EXOSC3 in a neuronal cell line. These data suggest that cells possess a mechanism for optimal assembly of functional RNA exosome complex that can discriminate between wild-type and variant exosome subunits. Budding yeast can therefore serve as a useful tool to understand the molecular defects in the RNA exosome caused by PCH1b-associated amino acid substitutions in EXOSC3, and potentially extending to disease-associated substitutions in other exosome subunits.
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102
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Maity A, Chaudhuri A, Das B. DRN and TRAMP degrade specific and overlapping aberrant mRNAs formed at various stages of mRNP biogenesis inSaccharomyces cerevisiae. FEMS Yeast Res 2016; 16:fow088. [DOI: 10.1093/femsyr/fow088] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2016] [Indexed: 01/08/2023] Open
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103
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Domanski M, Upla P, Rice WJ, Molloy KR, Ketaren NE, Stokes DL, Jensen TH, Rout MP, LaCava J. Purification and analysis of endogenous human RNA exosome complexes. RNA (NEW YORK, N.Y.) 2016; 22:1467-1475. [PMID: 27402899 PMCID: PMC4986900 DOI: 10.1261/rna.057760.116] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 06/14/2016] [Indexed: 06/06/2023]
Abstract
As a result of its importance in key RNA metabolic processes, the ribonucleolytic RNA exosome complex has been the focus of intense study for almost two decades. Research on exosome subunit assembly, cofactor and substrate interaction, enzymatic catalysis and structure have largely been conducted using complexes produced in the yeast Saccharomyces cerevisiae or in bacteria. Here, we examine different populations of endogenous exosomes from human embryonic kidney (HEK) 293 cells and test their enzymatic activity and structural integrity. We describe methods to prepare EXOSC10-containing, enzymatically active endogenous human exosomes at suitable yield and purity for in vitro biochemistry and negative stain transmission electron microscopy. This opens the door for assays designed to test the in vitro effects of putative cofactors on human exosome activity and will enable structural studies of preparations from endogenous sources.
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Affiliation(s)
- Michal Domanski
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, New York 10065, USA Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Paula Upla
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, New York 10065, USA Skirball Institute and Department of Cell Biology, New York University School of Medicine, New York, New York 10016, USA
| | - William J Rice
- Simons Electron Microscopy Center at New York Structural Biology Center, New York, New York 10027, USA
| | - Kelly R Molloy
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, New York 10065, USA
| | - Natalia E Ketaren
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, New York 10065, USA
| | - David L Stokes
- Skirball Institute and Department of Cell Biology, New York University School of Medicine, New York, New York 10016, USA
| | - Torben Heick Jensen
- Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Michael P Rout
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, New York 10065, USA
| | - John LaCava
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, New York 10065, USA Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
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104
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Mukherjee K, Gardin J, Futcher B, Leatherwood J. Relative contributions of the structural and catalytic roles of Rrp6 in exosomal degradation of individual mRNAs. RNA (NEW YORK, N.Y.) 2016; 22:1311-1319. [PMID: 27402898 PMCID: PMC4986887 DOI: 10.1261/rna.051490.115] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 06/02/2016] [Indexed: 06/06/2023]
Abstract
The RNA exosome is a conserved complex for RNA degradation with two ribonucleolytic subunits, Dis3 and Rrp6. Rrp6 is a 3'-5' exonuclease, but it also has a structural role in helping target RNAs to the Dis3 activity. The relative importance of the exonuclease activity and the targeting activity probably differs between different RNA substrates, but this is poorly understood. To understand the relative contributions of the exonuclease and the targeting activities to the degradation of individual RNA substrates in Schizosaccharomyces pombe, we compared RNA levels in an rrp6 null mutant to those in an rrp6 point mutant specifically defective in exonuclease activity. A wide range of effects was found, with some RNAs dependent mainly on the structural role of Rrp6 ("protein-dependent" targets), other RNAs dependent mainly on the catalytic role ("activity-dependent" targets), and some RNAs dependent on both. Some protein-dependent RNAs contained motifs targeted via the RNA-binding protein Mmi1, while others contained a motif possibly involved in response to iron. In these and other cases Rrp6 may act as a structural adapter to target specific RNAs to the exosome by interacting with sequence-specific RNA-binding proteins.
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Affiliation(s)
- Kaustav Mukherjee
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11794-5222, USA
| | - Justin Gardin
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11794-5222, USA
| | - Bruce Futcher
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11794-5222, USA
| | - Janet Leatherwood
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11794-5222, USA
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105
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McIver SC, Katsumura KR, Davids E, Liu P, Kang YA, Yang D, Bresnick EH. Exosome complex orchestrates developmental signaling to balance proliferation and differentiation during erythropoiesis. eLife 2016; 5. [PMID: 27543448 PMCID: PMC5040589 DOI: 10.7554/elife.17877] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 08/18/2016] [Indexed: 12/11/2022] Open
Abstract
Since the highly conserved exosome complex mediates the degradation and processing of multiple classes of RNAs, it almost certainly controls diverse biological processes. How this post-transcriptional RNA-regulatory machine impacts cell fate decisions and differentiation is poorly understood. Previously, we demonstrated that exosome complex subunits confer an erythroid maturation barricade, and the erythroid transcription factor GATA-1 dismantles the barricade by transcriptionally repressing the cognate genes. While dissecting requirements for the maturation barricade in Mus musculus, we discovered that the exosome complex is a vital determinant of a developmental signaling transition that dictates proliferation/amplification versus differentiation. Exosome complex integrity in erythroid precursor cells ensures Kit receptor tyrosine kinase expression and stem cell factor/Kit signaling, while preventing responsiveness to erythropoietin-instigated signals that promote differentiation. Functioning as a gatekeeper of this developmental signaling transition, the exosome complex controls the massive production of erythroid cells that ensures organismal survival in homeostatic and stress contexts. DOI:http://dx.doi.org/10.7554/eLife.17877.001 Red blood cells supply an animal’s tissues with the oxygen they need to survive. These cells circulate for a certain amount of time before they die. To replenish the red blood cells that are lost, first a protein called stem cell factor (SCF) instructs stem cells and precursor cells to proliferate, and a second protein, known as erythropoietin, then signals to these cells to differentiate into mature red blood cells. It is important to maintain this balance between these two processes because too much proliferation can lead to cancer while too much differentiation will exhaust the supply of stem cells. Previous work has shown that a collection of proteins called the exosome complex can block steps leading towards mature red blood cells. The exosome complex controls several processes within cells by modifying or degrading a variety of messenger RNAs, the molecules that serve as intermediates between DNA and protein. However, it was not clear how the exosome complex sets up the differentiation block and whether it is somehow connected to the signaling from SCF and erythropoietin. McIver et al. set out to address this issue by isolating precursor cells with the potential to become red blood cells from mouse fetal livers and experimentally reducing the levels of the exosome complex. The experiments showed that these cells were no longer able to respond when treated with SCF in culture, whereas the control cells responded as normal. Further experiments showed that cells with less of the exosome complex also made less of a protein named Kit. Normally, SCF interacts with Kit to instruct cells to multiply. Lastly, although the experimental cells could no longer respond to these proliferation signals, they could react to erythropoietin, which promotes differentiation. Thus, normal levels of the exosome complex keep the delicate balance between proliferation and differentiation, which is crucial to the development of red blood cells. In future, it will be important to study the exosome complex in living mice and in human cells, and to see whether it also controls other signaling pathways. Furthermore, it is worth exploring whether this new knowledge can help efforts to produce red blood cells on an industrial scale, which could then be used to treat patients with conditions such as anemia. DOI:http://dx.doi.org/10.7554/eLife.17877.002
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Affiliation(s)
- Skye C McIver
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, United States.,UW-Madison Blood Research Program, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - Koichi R Katsumura
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, United States.,UW-Madison Blood Research Program, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - Elsa Davids
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, United States.,UW-Madison Blood Research Program, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - Peng Liu
- Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - Yoon-A Kang
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, United States.,UW-Madison Blood Research Program, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - David Yang
- Department of Pathology, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - Emery H Bresnick
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, United States.,UW-Madison Blood Research Program, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States
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106
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Manier S, Salem KZ, Park J, Landau DA, Getz G, Ghobrial IM. Genomic complexity of multiple myeloma and its clinical implications. Nat Rev Clin Oncol 2016; 14:100-113. [DOI: 10.1038/nrclinonc.2016.122] [Citation(s) in RCA: 293] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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107
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A compendium of DIS3 mutations and associated transcriptional signatures in plasma cell dyscrasias. Oncotarget 2016; 6:26129-41. [PMID: 26305418 PMCID: PMC4694891 DOI: 10.18632/oncotarget.4674] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 07/06/2015] [Indexed: 12/22/2022] Open
Abstract
DIS3 is a catalytic subunit of the human exosome complex, containing exonucleolytic (RNB) and endonucleolytic (PIN) domains, recently found mutated in multiple myeloma (MM), a clinically and genetically heterogeneous form of plasma cell (PC) dyscrasia. We analyzed by next-generation sequencing (NGS) the DIS3 PIN and RNB domains in purified bone marrow PCs from 164 representative patients, including 130 cases with MM, 24 with primary PC leukemia and 10 with secondary PC leukemia. DIS3 mutations were found respectively in 18.5%, 25% and 30% of cases. Identified variants were predominantly missense mutations localized in the RNB domain, and were often detected at low allele frequency. DIS3 mutations were preferentially carried by IGH-translocated/nonhyperdiploid patients. Sequential analysis at diagnosis and relapse in a subset of cases highlighted some instances of increasing DIS3 mutation burden during disease progression. NGS also revealed that the majority of DIS3 variants in mutated cases were comparably detectable at transcriptional level. Furthermore, gene expression profiling analysis in DIS3-mutated patients identified a transcriptional signature suggestive for impaired RNA exosome function. In conclusion, these data further support the pathological relevance of DIS3 mutations in plasma cell dyscrasias and suggest that DIS3 may represent a potential tumor suppressor gene in such disorders.
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108
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Kowalinski E, Kögel A, Ebert J, Reichelt P, Stegmann E, Habermann B, Conti E. Structure of a Cytoplasmic 11-Subunit RNA Exosome Complex. Mol Cell 2016; 63:125-34. [PMID: 27345150 PMCID: PMC4942675 DOI: 10.1016/j.molcel.2016.05.028] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 04/26/2016] [Accepted: 05/18/2016] [Indexed: 10/28/2022]
Abstract
The RNA exosome complex associates with nuclear and cytoplasmic cofactors to mediate the decay, surveillance, or processing of a wide variety of transcripts. In the cytoplasm, the conserved core of the exosome (Exo10) functions together with the conserved Ski complex. The interaction of S. cerevisiae Exo10 and Ski is not direct but requires a bridging cofactor, Ski7. Here, we report the 2.65 Å resolution structure of S. cerevisiae Exo10 bound to the interacting domain of Ski7. Extensive hydrophobic interactions rationalize the high affinity and stability of this complex, pointing to Ski7 as a constitutive component of the cytosolic exosome. Despite the absence of sequence homology, cytoplasmic Ski7 and nuclear Rrp6 bind Exo10 using similar surfaces and recognition motifs. Knowledge of the interacting residues in the yeast complexes allowed us to identify a splice variant of human HBS1-Like as a Ski7-like exosome-binding protein, revealing the evolutionary conservation of this cytoplasmic cofactor.
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Affiliation(s)
- Eva Kowalinski
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Alexander Kögel
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Judith Ebert
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Peter Reichelt
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Elisabeth Stegmann
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Bianca Habermann
- Computational Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Elena Conti
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
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109
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Rodríguez-Galán O, García-Gómez JJ, Kressler D, de la Cruz J. Immature large ribosomal subunits containing the 7S pre-rRNA can engage in translation in Saccharomyces cerevisiae. RNA Biol 2016; 12:838-46. [PMID: 26151772 DOI: 10.1080/15476286.2015.1058477] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Evolution has provided eukaryotes with mechanisms that impede immature and/or aberrant ribosomes to engage in translation. These mechanisms basically either prevent the nucleo-cytoplasmic export of these particles or, once in the cytoplasm, the release of associated assembly factors, which interfere with the binding of translation initiation factors and/or the ribosomal subunit joining. We have previously shown that aberrant yeast 40S ribosomal subunits containing the 20S pre-rRNA can engage in translation. In this study, we describe that cells harbouring the dob1-1 allele, encoding a mutated version of the exosome-assisting RNA helicase Mtr4, accumulate otherwise nuclear pre-60S ribosomal particles containing the 7S pre-rRNA in the cytoplasm. Polysome fractionation analyses revealed that these particles are competent for translation and do not induce elongation stalls. This phenomenon is rather specific since most mutations in other exosome components or co-factors, impairing the 3' end processing of the mature 5.8S rRNA, accumulate 7S pre-rRNAs in the nucleus. In addition, we confirm that pre-60S ribosomal particles containing either 5.8S + 30 or 5.8S + 5 pre-rRNAs also engage in translation elongation. We propose that 7S pre-rRNA processing is not strictly required for pre-60S r-particle export and that, upon arrival in the cytoplasm, there is no specific mechanism to prevent translation by premature pre-60S r-particles containing 3' extended forms of mature 5.8S rRNA.
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Affiliation(s)
- Olga Rodríguez-Galán
- a Instituto de Biomedicina de Sevilla ; Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla ; Seville , Spain
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110
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Mosrin-Huaman C, Hervouet-Coste N, Rahmouni AR. Co-transcriptional degradation by the 5'-3' exonuclease Rat1p mediates quality control of HXK1 mRNP biogenesis in S. cerevisiae. RNA Biol 2016; 13:582-92. [PMID: 27124216 DOI: 10.1080/15476286.2016.1181255] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
The co-transcriptional biogenesis of export-competent messenger ribonucleoprotein particles (mRNPs) in yeast is under the surveillance of quality control (QC) steps. Aberrant mRNPs resulting from inappropriate or inefficient processing and packaging reactions are detected by the QC system and retained in the nucleus with ensuing elimination of their mRNA component by a mechanism that requires the catalytic activity of Rrp6p, a 3'-5' exonuclease associated with the RNA exosome. In previous studies, we implemented a new experimental approach in which the production of aberrant mRNPs is massively increased upon perturbation of mRNP biogenesis by the RNA-dependent helicase/translocase activity of the bacterial Rho factor expressed in S. cerevisiae. The analyses of a subset of transcripts such as PMA1 led us to substantiate the essential role of Rrp6p in the nuclear mRNP QC and to reveal a functional coordination of the process by Nrd1p. Here, we extended those results by showing that, in contrast to PMA1, Rho-induced aberrant HXK1 mRNPs are targeted for destruction by an Nrd1p- and Rrp6p-independent alternative QC pathway that relies on the 5'-3' exonuclease activity of Rat1p. We show that the degradation of aberrant HXK1 mRNPs by Rat1p occurs co-transcriptionally following decapping by Dcp2p and leads to premature transcription termination. We discuss the possibility that this alternative QC pathway might be linked to the well-known specific features of the HXK1 gene transcription such as its localization at the nuclear periphery and gene loop formation.
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Affiliation(s)
| | | | - A Rachid Rahmouni
- a Centre de Biophysique Moléculaire , Rue Charles Sadron , Orléans , France
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111
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Rougemaille M, Libri D. Control of cryptic transcription in eukaryotes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 702:122-31. [PMID: 21713682 DOI: 10.1007/978-1-4419-7841-7_10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Over the last few years, the development of large-scale technologies has radically modified our conception of genome-wide transcriptional control by unveiling an unexpected high complexity of the eukaryotic transcriptome. In organisms ranging from yeast to human, a considerable number of novel small RNA species have been discovered in regions that were previously thought to be incompatible with high levels of transcription. Intriguingly, these transcripts, which are rapidly targeted for degradation by the exosome, appear to be devoid of any coding potential and may be the consequence of unwanted transcription events. However, the notion that an important fraction of these RNAs represent by-products of regulatory transcription is progressively emerging. In this chapter, we discuss the recent advances made in our understanding of the shape of the eukaryotic transcriptome. We also focus on the molecular mechanisms that cells exploit to prevent cryptic transcripts from interfering with the expression of protein-coding genes. Finally, we summarize data obtained in different systems suggesting that such RNAs may play a critical role in the regulation of gene expression as well as the evolution of genomes.
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Affiliation(s)
- Mathieu Rougemaille
- LEA Laboratory of Nuclear RNA Metabolism, Centre de Génétique Moléculaire, CNRS-UPR2167, Gif-sur-Yvette, France,
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112
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Vuković L, Chipot C, Makino DL, Conti E, Schulten K. Molecular Mechanism of Processive 3' to 5' RNA Translocation in the Active Subunit of the RNA Exosome Complex. J Am Chem Soc 2016; 138:4069-78. [PMID: 26928279 PMCID: PMC4988868 DOI: 10.1021/jacs.5b12065] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Recent experimental studies revealed structural details of 3' to 5' degradation of RNA molecules, performed by the exosome complex. ssRNA is channeled through its multisubunit ring-like core into the active site tunnel of its key exonuclease subunit Rrp44, which acts both as an enzyme and a motor. Even in isolation, Rrp44 can pull and sequentially cleave RNA nucleotides, one at a time, without any external energy input and release a final 3-5 nucleotide long product. Using molecular dynamics simulations, we identify the main factors that control these processes. Our free energy calculations reveal that RNA transfer from solution into the active site of Rrp44 is highly favorable, but dependent on the length of the RNA strand. While RNA strands formed by 5 nucleotides or more correspond to a decreasing free energy along the translocation coordinate toward the cleavage site, a 4-nucleotide RNA experiences a free energy barrier along the same direction, potentially leading to incomplete cleavage of ssRNA and the release of short (3-5) nucleotide products. We provide new insight into how Rrp44 catalyzes a localized enzymatic reaction and performs an action distributed over several RNA nucleotides, leading eventually to the translocation of whole RNA segments into the position suitable for cleavage.
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Affiliation(s)
- Lela Vuković
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
- Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
- epartment of Chemistry, University of Texas at El Paso, El Paso, TX 79968, United States
| | - Christophe Chipot
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
- Laboratoire International Associé CNRS-University of Illinois, Université de Lorraine, Vandoeuvre-lès-Nancy, France
| | - Debora L. Makino
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Elena Conti
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Klaus Schulten
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
- Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
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113
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Collaborative Control of Cell Cycle Progression by the RNA Exonuclease Dis3 and Ras Is Conserved Across Species. Genetics 2016; 203:749-62. [PMID: 27029730 DOI: 10.1534/genetics.116.187930] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 03/26/2016] [Indexed: 11/18/2022] Open
Abstract
Dis3 encodes a conserved RNase that degrades or processes all RNA species via an N-terminal PilT N terminus (PIN) domain and C-terminal RNB domain that harbor, respectively, endonuclease activity and 3'-5' exonuclease activity. In Schizosaccharomyces pombe, dis3 mutations cause chromosome missegregation and failure in mitosis, suggesting dis3 promotes cell division. In humans, apparently hypomorphic dis3 mutations are found recurrently in multiple myeloma, suggesting dis3 opposes cell division. Except for the observation that RNAi-mediated depletion of dis3 function drives larval arrest and reduces tissue growth in Drosophila, the role of dis3 has not been rigorously explored in higher eukaryotic systems. Using the Drosophila system and newly generated dis3 null alleles, we find that absence of dis3 activity inhibits cell division. We uncover a conserved CDK1 phosphorylation site that when phosphorylated inhibits Dis3's exonuclease, but not endonuclease, activity. Leveraging this information, we show that Dis3's exonuclease function is required for mitotic cell division: in its absence, cells are delayed in mitosis and exhibit aneuploidy and overcondensed chromosomes. In contrast, we find that modest reduction of dis3 function enhances cell proliferation in the presence of elevated Ras activity, apparently by accelerating cells through G2/M even though each insult by itself delays G2/M. Additionally, we find that dis3 and ras genetically interact in worms and that dis3 can enhance cell proliferation under growth stimulatory conditions in murine B cells. Thus, reduction, but not absence, of dis3 activity can enhance cell proliferation in higher organisms.
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114
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Jackson RA, Wu JS, Chen ES. C1D family proteins in coordinating RNA processing, chromosome condensation and DNA damage response. Cell Div 2016; 11:2. [PMID: 27030795 PMCID: PMC4812661 DOI: 10.1186/s13008-016-0014-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 02/22/2016] [Indexed: 12/02/2022] Open
Abstract
Research on the involvement of C1D and its yeast homologues Rrp47 (S. cerevisiae) and Cti1 (S. pombe) in DNA damage repair and RNA processing has remained mutually exclusive, with most studies predominantly concentrating on Rrp47. This review will look to reconcile the functions of these proteins in their involvement with the RNA exosome, in the regulation of chromatin architecture, and in the repair of DNA double-strand breaks, focusing on non-homologous end joining and homologous recombination. We propose that C1D is situated in a central position to maintain genomic stability at highly transcribed gene loci by coordinating these processes through the timely recruitment of relevant regulatory factors. In the event that the damage is beyond repair, C1D induces apoptosis in a p53-dependent manner.
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Affiliation(s)
- Rebecca A Jackson
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597 Singapore
| | - Jocelyn Shumei Wu
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597 Singapore
| | - Ee Sin Chen
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597 Singapore ; National University Health System (NUHS), Singapore, 119228 Singapore ; NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, 119228 Singapore
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Audin MJC, Wurm JP, Cvetkovic MA, Sprangers R. The oligomeric architecture of the archaeal exosome is important for processive and efficient RNA degradation. Nucleic Acids Res 2016; 44:2962-73. [PMID: 26837575 PMCID: PMC4824110 DOI: 10.1093/nar/gkw062] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 01/25/2016] [Indexed: 11/30/2022] Open
Abstract
The exosome plays an important role in RNA degradation and processing. In archaea, three Rrp41:Rrp42 heterodimers assemble into a barrel like structure that contains a narrow RNA entrance pore and a lumen that contains three active sites. Here, we demonstrate that this quaternary structure of the exosome is important for efficient RNA degradation. We find that the entrance pore of the barrel is required for nM substrate affinity. This strong interaction is crucial for processive substrate degradation and prevents premature release of the RNA from the enzyme. Using methyl TROSY NMR techniques, we establish that the 3′ end of the substrate remains highly flexible inside the lumen. As a result, the RNA jumps between the three active sites that all equally participate in substrate degradation. The RNA jumping rate is, however, much faster than the cleavage rate, indicating that not all active site:substrate encounters result in catalysis. Enzymatic turnover therefore benefits from the confinement of the active sites and substrate in the lumen, which ensures that the RNA is at all times bound to one of the active sites. The evolution of the exosome into a hexameric complex and the optimization of its catalytic efficiency were thus likely co-occurring events.
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Affiliation(s)
- Maxime J C Audin
- Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076 Tübingen, Germany
| | - Jan Philip Wurm
- Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076 Tübingen, Germany
| | - Milos A Cvetkovic
- Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076 Tübingen, Germany
| | - Remco Sprangers
- Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076 Tübingen, Germany
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Li Y, Burclaff J, Anderson JT. Mutations in Mtr4 Structural Domains Reveal Their Important Role in Regulating tRNAiMet Turnover in Saccharomyces cerevisiae and Mtr4p Enzymatic Activities In Vitro. PLoS One 2016; 11:e0148090. [PMID: 26820724 PMCID: PMC4731217 DOI: 10.1371/journal.pone.0148090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 01/12/2016] [Indexed: 12/24/2022] Open
Abstract
RNA processing and turnover play important roles in the maturation, metabolism and quality control of a large variety of RNAs thereby contributing to gene expression and cellular health. The TRAMP complex, composed of Air2p, Trf4p and Mtr4p, stimulates nuclear exosome-dependent RNA processing and degradation in Saccharomyces cerevisiae. The Mtr4 protein structure is composed of a helicase core and a novel so-called arch domain, which protrudes from the core. The helicase core contains highly conserved helicase domains RecA-1 and 2, and two structural domains of unclear functions, winged helix domain (WH) and ratchet domain. How the structural domains (arch, WH and ratchet domain) coordinate with the helicase domains and what roles they are playing in regulating Mtr4p helicase activity are unknown. We created a library of Mtr4p structural domain mutants for the first time and screened for those defective in the turnover of TRAMP and exosome substrate, hypomodified tRNAiMet. We found these domains regulate Mtr4p enzymatic activities differently through characterizing the arch domain mutants K700N and P731S, WH mutant K904N, and ratchet domain mutant R1030G. Arch domain mutants greatly reduced Mtr4p RNA binding, which surprisingly did not lead to significant defects on either in vivo tRNAiMet turnover, or in vitro unwinding activities. WH mutant K904N and Ratchet domain mutant R1030G showed decreased tRNAiMet turnover in vivo, as well as reduced RNA binding, ATPase and unwinding activities of Mtr4p in vitro. Particularly, K904 was found to be very important for steady protein levels in vivo. Overall, we conclude that arch domain plays a role in RNA binding but is largely dispensable for Mtr4p enzymatic activities, however the structural domains in the helicase core significantly contribute to Mtr4p ATPase and unwinding activities.
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Affiliation(s)
- Yan Li
- College of Veterinary Medicine, Agricultural University of Hebei, Baoding, Hebei, 071001, China
| | - Joseph Burclaff
- Division of Biology and Biomedical Sciences, Washington University, St. Louis, MO, 63110, United States of America
| | - James T. Anderson
- Department of Biological Sciences, Marquette University, Milwaukee, WI, 53233, United States of America
- * E-mail:
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117
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The regulation and functions of the nuclear RNA exosome complex. Nat Rev Mol Cell Biol 2016; 17:227-39. [PMID: 26726035 DOI: 10.1038/nrm.2015.15] [Citation(s) in RCA: 268] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The RNA exosome complex is the most versatile RNA-degradation machine in eukaryotes. The exosome has a central role in several aspects of RNA biogenesis, including RNA maturation and surveillance. Moreover, it is emerging as an important player in regulating the expression levels of specific mRNAs in response to environmental cues and during cell differentiation and development. Although the mechanisms by which RNA is targeted to (or escapes from) the exosome are still not fully understood, general principles have begun to emerge, which we discuss in this Review. In addition, we introduce and discuss novel, previously unappreciated functions of the nuclear exosome, including in transcription regulation and in the maintenance of genome stability.
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118
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Abstract
Multiple myeloma (MM) is a genetically complex disease. The past few years have seen an evolution in cancer research with the emergence of next-generation sequencing (NGS), enabling high throughput sequencing of tumors-including whole exome, whole genome, RNA, and single-cell sequencing as well as genome-wide association study (GWAS). A few inherited variants have been described, counting for some cases of familial disease. Hierarchically, primary events in MM can be divided into hyperdiploid (HDR) and nonhyperdiploid subtypes. HRD tumors are characterized by trisomy of chromosomes 3, 5, 7, 9, 11, 15, 19, and/or 21. Non-HRD tumors harbor IGH translocations, mainly t(4;14), t(6;14), t(11;14), t(14;16), and t(14;20). Secondary events participate to the tumor progression and consist in secondary translocation involving MYC, copy number variations (CNV) and somatic mutations (such as mutations in KRAS, NRAS, BRAF, P53). Moreover, the dissection of clonal heterogeneity helps to understand the evolution of the disease. The following review provides a comprehensive review of the genomic landscape in MM.
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Affiliation(s)
- Salomon Manier
- Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, USA
- Department of Hematology, Lille Hospital University, Lille, France
| | - Karma Salem
- Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, USA
| | - Siobhan V Glavey
- Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, USA
| | - Aldo M Roccaro
- Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, USA
- Department of Hematology, CREA Laboratory, ASST-Spedali Civili di Brescia, Brescia, BS, Italy
| | - Irene M Ghobrial
- Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, USA.
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Siwaszek A, Ukleja M, Dziembowski A. Proteins involved in the degradation of cytoplasmic mRNA in the major eukaryotic model systems. RNA Biol 2015; 11:1122-36. [PMID: 25483043 DOI: 10.4161/rna.34406] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The process of mRNA decay and surveillance is considered to be one of the main posttranscriptional gene expression regulation platforms in eukaryotes. The degradation of stable, protein-coding transcripts is normally initiated by removal of the poly(A) tail followed by 5'-cap hydrolysis and degradation of the remaining mRNA body by Xrn1. Alternatively, the exosome complex degrades mRNA in the 3'>5'direction. The newly discovered uridinylation-dependent pathway, which is present in many different organisms, also seems to play a role in bulk mRNA degradation. Simultaneously, to avoid the synthesis of incorrect proteins, special cellular machinery is responsible for the removal of faulty transcripts via nonsense-mediated, no-go, non-stop or non-functional 18S rRNA decay. This review is focused on the major eukaryotic cytoplasmic mRNA degradation pathways showing many similarities and pointing out main differences between the main model-species: yeast, Drosophila, plants and mammals.
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Affiliation(s)
- Aleksandra Siwaszek
- a Institute of Biochemistry and Biophysics ; Polish Academy of Sciences ; Warsaw , Poland
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120
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Edmondson AC, Kalish JM. Overgrowth Syndromes. J Pediatr Genet 2015; 4:136-43. [PMID: 27617124 PMCID: PMC4918719 DOI: 10.1055/s-0035-1564440] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 05/20/2015] [Indexed: 01/19/2023]
Abstract
Numerous multiple malformation syndromes associated with pathologic overgrowth have been described and, for many, their molecular bases elucidated. This review describes the characteristic features of these overgrowth syndromes, as well as the current understanding of their molecular bases, intellectual outcomes, and cancer predispositions. We review syndromes such as Sotos, Malan, Marshall-Smith, Weaver, Simpson-Golabi-Behmel, Perlman, Bannayan-Riley-Ruvalcaba, PI3K-related, Proteus, Beckwith-Wiedemann, fibrous dysplasia, Klippel-Trenaunay-Weber, and Maffucci.
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Affiliation(s)
- Andrew C. Edmondson
- Division of Human Genetics, Children's Hospital of Philadelphia and Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Jennifer M. Kalish
- Division of Human Genetics, Children's Hospital of Philadelphia and Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States
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121
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Szczepińska T, Kalisiak K, Tomecki R, Labno A, Borowski LS, Kulinski TM, Adamska D, Kosinska J, Dziembowski A. DIS3 shapes the RNA polymerase II transcriptome in humans by degrading a variety of unwanted transcripts. Genome Res 2015; 25:1622-33. [PMID: 26294688 PMCID: PMC4617959 DOI: 10.1101/gr.189597.115] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 07/16/2015] [Indexed: 01/13/2023]
Abstract
Human DIS3, the nuclear catalytic subunit of the exosome complex, contains exonucleolytic and endonucleolytic active domains. To identify DIS3 targets genome-wide, we combined comprehensive transcriptomic analyses of engineered HEK293 cells that expressed mutant DIS3, with Photoactivatable Ribonucleoside-Enhanced Cross-Linking and Immunoprecipitation (PAR-CLIP) experiments. In cells expressing DIS3 with both catalytic sites mutated, RNAs originating from unannotated genomic regions increased ∼2.5-fold, covering ∼70% of the genome and allowing for thousands of novel transcripts to be discovered. Previously described pervasive transcription products, such as Promoter Upstream Transcripts (PROMPTs), accumulated robustly upon DIS3 dysfunction, representing a significant fraction of PAR-CLIP reads. We have also detected relatively long putative premature RNA polymerase II termination products of protein-coding genes whose levels in DIS3 mutant cells can exceed the mature mRNAs, indicating that production of such truncated RNA is a common phenomenon. In addition, we found DIS3 to be involved in controlling the formation of paraspeckles, nuclear bodies that are organized around NEAT1 lncRNA, whose short form was overexpressed in cells with mutated DIS3. Moreover, the DIS3 mutations resulted in misregulation of expression of ∼50% of transcribed protein-coding genes, probably as a secondary effect of accumulation of various noncoding RNA species. Finally, cells expressing mutant DIS3 accumulated snoRNA precursors, which correlated with a strong PAR-CLIP signal, indicating that DIS3 is the main snoRNA-processing enzyme. EXOSC10 (RRP6) instead controls the levels of the mature snoRNAs. Overall, we show that DIS3 has a major nucleoplasmic function in shaping the human RNA polymerase II transcriptome.
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Affiliation(s)
- Teresa Szczepińska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Katarzyna Kalisiak
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Rafal Tomecki
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Anna Labno
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Lukasz S Borowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Tomasz M Kulinski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Dorota Adamska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Joanna Kosinska
- Department of Medical Genetics, Center for Biostructure Research, Medical University of Warsaw, 02-106 Warsaw, Poland
| | - Andrzej Dziembowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
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123
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Robinson SR, Oliver AW, Chevassut TJ, Newbury SF. The 3' to 5' Exoribonuclease DIS3: From Structure and Mechanisms to Biological Functions and Role in Human Disease. Biomolecules 2015; 5:1515-39. [PMID: 26193331 PMCID: PMC4598762 DOI: 10.3390/biom5031515] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/01/2015] [Accepted: 07/06/2015] [Indexed: 12/03/2022] Open
Abstract
DIS3 is a conserved exoribonuclease and catalytic subunit of the exosome, a protein complex involved in the 3' to 5' degradation and processing of both nuclear and cytoplasmic RNA species. Recently, aberrant expression of DIS3 has been found to be implicated in a range of different cancers. Perhaps most striking is the finding that DIS3 is recurrently mutated in 11% of multiple myeloma patients. Much work has been done to elucidate the structural and biochemical characteristics of DIS3, including the mechanistic details of its role as an effector of RNA decay pathways. Nevertheless, we do not understand how DIS3 mutations can lead to cancer. There are a number of studies that pertain to the function of DIS3 at the organismal level. Mutant phenotypes in S. pombe, S. cerevisiae and Drosophila suggest DIS3 homologues have a common role in cell-cycle progression and microtubule assembly. DIS3 has also recently been implicated in antibody diversification of mouse B-cells. This article aims to review current knowledge of the structure, mechanisms and functions of DIS3 as well as highlighting the genetic patterns observed within myeloma patients, in order to yield insight into the putative role of DIS3 mutations in oncogenesis.
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Affiliation(s)
- Sophie R Robinson
- Medical Research Building, Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton BN1 9PS, UK.
| | - Antony W Oliver
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK.
| | - Timothy J Chevassut
- Medical Research Building, Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton BN1 9PS, UK.
| | - Sarah F Newbury
- Medical Research Building, Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton BN1 9PS, UK.
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Abstract
The immunoglobulin diversification processes of somatic hypermutation and class switch recombination critically rely on transcription-coupled targeting of activation-induced cytidine deaminase (AID) to Ig loci in activated B lymphocytes. AID catalyzes deamination of cytidine deoxynucleotides on exposed single-stranded DNA. In addition to driving immunoglobulin diversity, promiscuous targeting of AID mutagenic activity poses a deleterious threat to genomic stability. Recent genome-wide studies have uncovered pervasive AID activity throughout the B cell genome. It is increasingly apparent that AID activity is frequently targeted to genomic loci undergoing early transcription termination where RNA exosome promotes the resolution of stalled transcription complexes via cotranscriptional RNA degradation mechanisms. Here, we review aspects and consequences of eukaryotic transcription that lead to early termination, RNA exosome recruitment, and ultimately targeting of AID mutagenic activity.
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Affiliation(s)
- Evangelos Pefanis
- Department of Microbiology & Immunology, College of Physicians and Surgeons, Columbia University, New York, USA.
| | - Uttiya Basu
- Department of Microbiology & Immunology, College of Physicians and Surgeons, Columbia University, New York, USA.
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125
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Lv H, Zhu Y, Qiu Y, Niu L, Teng M, Li X. Structural analysis of Dis3l2, an exosome-independent exonuclease from Schizosaccharomyces pombe. ACTA ACUST UNITED AC 2015; 71:1284-94. [PMID: 26057668 DOI: 10.1107/s1399004715005805] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 03/23/2015] [Indexed: 01/04/2023]
Abstract
After deadenylation and decapping, cytoplasmic mRNA can be digested in two opposite directions: in the 5'-3' direction by Xrn1 or in the 3'-5' direction by the exosome complex. Recently, a novel 3'-5' RNA-decay pathway involving Dis3l2 has been described that differs from degradation by Xrn1 and the exosome. The product of the Schizosaccharomyces pombe gene SPAC2C4.07c was identified as a homologue of human Dis3l2. In this work, the 2.8 Å resolution X-ray crystal structure of S. pombe Dis3l2 (SpDis3l2) is reported, the conformation of which is obviously different from that in the homologous mouse Dis3l2-RNA complex. Fluorescence polarization assay experiments showed that RNB and S1 are the primary RNA-binding domains and that the CSDs (CSD1 and CSD2) play an indispensable role in the RNA-binding process of SpDis3l2. Taking the structure comparison and mutagenic experiments together, it can be inferred that the RNA-recognition pattern of SpDis3l2 resembles that of its mouse homologue rather than that of the Escherichia coli RNase II-RNA complex. Furthermore, a drastic conformation change could occur following the binding of the RNA substrate to SpDis3l2.
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Affiliation(s)
- Hui Lv
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Yuwei Zhu
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Yu Qiu
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Liwen Niu
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Maikun Teng
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Xu Li
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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126
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Abstract
The exosome ribonuclease complex functions in both the limited trimming of the 3'-ends of nuclear substrates during RNA processing events and the complete destruction of nuclear and cytoplasmic RNAs. The two RNases of the eukaryotic exosome, Rrp44 (rRNA-processing protein 44) and Rrp6, are bound at either end of a catalytically inert cylindrical core. RNA substrates are threaded through the internal channel of the core to Rrp44 by RNA helicase components of the nuclear TRAMP complex (Trf4-Air2-Mtr4 polyadenylation complex) or the cytoplasmic Ski (superkiller) complex. Recent studies reveal that Rrp44 can also associate directly with substrates via channel-independent routes. Although the substrates of the exosome are known, it is not clear whether specific substrates are restricted to one or other pathway. Data currently available support the model that processed substrates are targeted directly to the catalytic subunits, whereas at least some substrates that are directed towards discard pathways must be threaded through the exosome core.
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127
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Hakhverdyan Z, Domanski M, Hough LE, Oroskar AA, Oroskar AR, Keegan S, Dilworth DJ, Molloy KR, Sherman V, Aitchison JD, Fenyö D, Chait BT, Jensen TH, Rout MP, LaCava J. Rapid, optimized interactomic screening. Nat Methods 2015; 12:553-60. [PMID: 25938370 PMCID: PMC4449307 DOI: 10.1038/nmeth.3395] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 03/03/2015] [Indexed: 12/25/2022]
Abstract
We must reliably map the interactomes of cellular macromolecular
complexes in order to fully explore and understand biological systems. However,
there are no methods to accurately predict how to capture a given macromolecular
complex with its physiological binding partners. Here, we present a screen that
comprehensively explores the parameters affecting the stability of interactions
in affinity-captured complexes, enabling the discovery of physiological binding
partners and the elucidation of their functional interactions in unparalleled
detail. We have implemented this screen on several macromolecular complexes from
a variety of organisms, revealing novel profiles even for well-studied proteins.
Our approach is robust, economical and automatable, providing an inroad to the
rigorous, systematic dissection of cellular interactomes.
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Affiliation(s)
- Zhanna Hakhverdyan
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, New York, USA
| | - Michal Domanski
- 1] Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, New York, USA. [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Loren E Hough
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, New York, USA
| | | | | | - Sarah Keegan
- 1] Center for Health Informatics and Bioinformatics, New York University School of Medicine, New York, New York, USA. [2] Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, USA
| | - David J Dilworth
- 1] Institute for Systems Biology, Seattle, Washington, USA. [2] Seattle Biomedical Research Institute, Seattle, Washington, USA
| | - Kelly R Molloy
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, New York, USA
| | - Vadim Sherman
- High Energy Physics Instrument Shop, The Rockefeller University, New York, New York, USA
| | - John D Aitchison
- 1] Institute for Systems Biology, Seattle, Washington, USA. [2] Seattle Biomedical Research Institute, Seattle, Washington, USA
| | - David Fenyö
- 1] Center for Health Informatics and Bioinformatics, New York University School of Medicine, New York, New York, USA. [2] Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, New York, USA
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Michael P Rout
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, New York, USA
| | - John LaCava
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, New York, USA
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Nab3 facilitates the function of the TRAMP complex in RNA processing via recruitment of Rrp6 independent of Nrd1. PLoS Genet 2015; 11:e1005044. [PMID: 25775092 PMCID: PMC4361618 DOI: 10.1371/journal.pgen.1005044] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 01/30/2015] [Indexed: 11/26/2022] Open
Abstract
Non-coding RNAs (ncRNAs) play critical roles in gene regulation. In eukaryotic cells, ncRNAs are processed and/or degraded by the nuclear exosome, a ribonuclease complex containing catalytic subunits Dis3 and Rrp6. The TRAMP (Trf4/5-Air1/2-Mtr4 polyadenylation) complex is a critical exosome cofactor in budding yeast that stimulates the exosome to process/degrade ncRNAs and human TRAMP components have recently been identified. Importantly, mutations in exosome and exosome cofactor genes cause neurodegenerative disease. How the TRAMP complex interacts with other exosome cofactors to orchestrate regulation of the exosome is an open question. To identify novel interactions of the TRAMP exosome cofactor, we performed a high copy suppressor screen of a thermosensitive air1/2 TRAMP mutant. Here, we report that the Nab3 RNA-binding protein of the Nrd1-Nab3-Sen1 (NNS) complex is a potent suppressor of TRAMP mutants. Unlike Nab3, Nrd1 and Sen1 do not suppress TRAMP mutants and Nrd1 binding is not required for Nab3-mediated suppression of TRAMP suggesting an independent role for Nab3. Critically, Nab3 decreases ncRNA levels in TRAMP mutants, Nab3-mediated suppression of air1/2 cells requires the nuclear exosome component, Rrp6, and Nab3 directly binds Rrp6. We extend this analysis to identify a human RNA binding protein, RALY, which shares identity with Nab3 and can suppress TRAMP mutants. These results suggest that Nab3 facilitates TRAMP function by recruiting Rrp6 to ncRNAs for processing/degradation independent of Nrd1. The data raise the intriguing possibility that Nab3 and Nrd1 can function independently to recruit Rrp6 to ncRNA targets, providing combinatorial flexibility in RNA processing. Eukaryotic genomes from yeast to man express numerous non-coding RNAs (ncRNAs) that regulate the expression of messenger RNAs (mRNAs) encoding the proteins vital for cell and body function. As faulty ncRNAs impair mRNA expression and contribute to cancers and neurodegenerative disease, it is imperative to understand how ncRNAs are processed and/or degraded. In budding yeast, a conserved RNA shredding machine known as the exosome nibbles at or destroys ncRNAs. The exosome is assisted by a conserved TRAMP exosome cofactor that recruits the exosome to ncRNAs for processing/ degradation. To better understand TRAMP function, we performed a genetic screen to identify genes that improve the growth of TRAMP mutant yeast cells that grow poorly at high temperature. We find that overexpression of the Nab3 RNA binding protein, which belongs to another exosome cofactor, the Nrd1-Nab3-Sen1 (NNS) complex, improves the growth of TRAMP mutant cells. Importantly, Nab3 requires the exosome to improve the growth and ncRNA processing of TRAMP mutant cells. We therefore suggest that Nab3 facilitates TRAMP function by recruiting the exosome to ncRNAs for processing/degradation. We also show that the human RNA binding protein, RALY, like Nab3, can improve the growth of TRAMP mutant cells.
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129
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Tomecki R, Drazkowska K, Krawczyk A, Kowalska K, Dziembowski A. Purification of eukaryotic exoribonucleases following heterologous expression in bacteria and analysis of their biochemical properties by in vitro enzymatic assays. Methods Mol Biol 2015; 1259:417-452. [PMID: 25579600 DOI: 10.1007/978-1-4939-2214-7_25] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Exoribonucleases-among the other RNases-play a crucial role in the regulation of different aspects of RNA metabolism in the eukaryotic cell. To fully understand the exact mechanism of activity exhibited by such enzymes, it is crucial to determine their detailed biochemical properties, notably their substrate specificity and optimal conditions for enzymatic action. One of the most significant features of exoribonucleases is the direction of degradation of RNA substrates, which can proceed either from 5'-end to 3'-end or in the opposite way. Here, we present methods allowing the efficient production and purification of eukaryotic exoribonucleases, the preparation and labeling of various RNA substrates, and the biochemical characterization of exonucleolytic activity. We also explain how the exonucleolytic activity may be distinguished from that of endonucleases.
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Affiliation(s)
- Rafal Tomecki
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland,
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Fernández-Pevida A, Kressler D, de la Cruz J. Processing of preribosomal RNA in Saccharomyces cerevisiae. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 6:191-209. [PMID: 25327757 DOI: 10.1002/wrna.1267] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/02/2014] [Accepted: 09/02/2014] [Indexed: 11/07/2022]
Abstract
Most, if not all RNAs, are transcribed as precursors that require processing to gain functionality. Ribosomal RNAs (rRNA) from all organisms undergo both exo- and endonucleolytic processing. Also, in all organisms, rRNA processing occurs inside large preribosomal particles and is coupled to nucleotide modification, folding of the precursor rRNA (pre-rRNA), and assembly of the ribosomal proteins (r-proteins). In this review, we focus on the processing pathway of pre-rRNAs of cytoplasmic ribosomes in the yeast Saccharomyces cerevisiae, without doubt, the organism where this pathway is best characterized. We summarize the current understanding of the rRNA maturation process, particularly focusing on the pre-rRNA processing sites, the enzymes responsible for the cleavage or trimming reactions and the different mechanisms that monitor and regulate the pathway. Strikingly, the overall order of the various processing steps is reasonably well conserved in eukaryotes, perhaps reflecting common principles for orchestrating the concomitant events of pre-rRNA processing and ribosome assembly.
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Affiliation(s)
- Antonio Fernández-Pevida
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain; Departamento de Genética, Universidad de Sevilla, Sevilla, Spain
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131
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Hou L, Klug G, Evguenieva-Hackenberg E. Archaeal DnaG contains a conserved N-terminal RNA-binding domain and enables tailing of rRNA by the exosome. Nucleic Acids Res 2014; 42:12691-706. [PMID: 25326320 PMCID: PMC4227792 DOI: 10.1093/nar/gku969] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The archaeal exosome is a phosphorolytic 3′–5′ exoribonuclease complex. In a reverse reaction it synthesizes A-rich RNA tails. Its RNA-binding cap comprises the eukaryotic orthologs Rrp4 and Csl4, and an archaea-specific subunit annotated as DnaG. In Sulfolobus solfataricus DnaG and Rrp4 but not Csl4 show preference for poly(rA). Archaeal DnaG contains N- and C-terminal domains (NTD and CTD) of unknown function flanking a TOPRIM domain. We found that the NT and TOPRIM domains have comparable, high conservation in all archaea, while the CTD conservation correlates with the presence of exosome. We show that the NTD is a novel RNA-binding domain with poly(rA)-preference cooperating with the TOPRIM domain in binding of RNA. Consistently, a fusion protein containing full-length Csl4 and NTD of DnaG led to enhanced degradation of A-rich RNA by the exosome. We also found that DnaG strongly binds native and invitro transcribed rRNA and enables its polynucleotidylation by the exosome. Furthermore, rRNA-derived transcripts with heteropolymeric tails were degraded faster by the exosome than their non-tailed variants. Based on our data, we propose that archaeal DnaG is an RNA-binding protein, which, in the context of the exosome, is involved in targeting of stable RNA for degradation.
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Affiliation(s)
- Linlin Hou
- Institute of Microbiology and Molecular Biology, Heinrich-Buff-Ring 26-32, D-35392 Gießen, Germany
| | - Gabriele Klug
- Institute of Microbiology and Molecular Biology, Heinrich-Buff-Ring 26-32, D-35392 Gießen, Germany
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132
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Schuch B, Feigenbutz M, Makino DL, Falk S, Basquin C, Mitchell P, Conti E. The exosome-binding factors Rrp6 and Rrp47 form a composite surface for recruiting the Mtr4 helicase. EMBO J 2014; 33:2829-46. [PMID: 25319414 DOI: 10.15252/embj.201488757] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The exosome is a conserved multi-subunit ribonuclease complex that functions in 3' end processing, turnover and surveillance of nuclear and cytoplasmic RNAs. In the yeast nucleus, the 10-subunit core complex of the exosome (Exo-10) physically and functionally interacts with the Rrp6 exoribonuclease and its associated cofactor Rrp47, the helicase Mtr4 and Mpp6. Here, we show that binding of Mtr4 to Exo-10 in vitro is dependent upon both Rrp6 and Rrp47, whereas Mpp6 binds directly and independently of other cofactors. Crystallographic analyses reveal that the N-terminal domains of Rrp6 and Rrp47 form a highly intertwined structural unit. Rrp6 and Rrp47 synergize to create a composite and conserved surface groove that binds the N-terminus of Mtr4. Mutation of conserved residues within Rrp6 and Mtr4 at the structural interface disrupts their interaction and inhibits growth of strains expressing a C-terminal GFP fusion of Mtr4. These studies provide detailed structural insight into the interaction between the Rrp6-Rrp47 complex and Mtr4, revealing an important link between Mtr4 and the core exosome.
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Affiliation(s)
- Benjamin Schuch
- Structural Cell Biology Department, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Monika Feigenbutz
- Molecular Biology and Biotechnology Department, The University of Sheffield, Sheffield, UK
| | - Debora L Makino
- Structural Cell Biology Department, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Sebastian Falk
- Structural Cell Biology Department, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Claire Basquin
- Structural Cell Biology Department, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Phil Mitchell
- Molecular Biology and Biotechnology Department, The University of Sheffield, Sheffield, UK
| | - Elena Conti
- Structural Cell Biology Department, Max Planck Institute of Biochemistry, Martinsried, Germany
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133
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Liu X, Zheng Q, Vrettos N, Maragkakis M, Alexiou P, Gregory BD, Mourelatos Z. A MicroRNA precursor surveillance system in quality control of MicroRNA synthesis. Mol Cell 2014; 55:868-879. [PMID: 25175028 DOI: 10.1016/j.molcel.2014.07.017] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 06/17/2014] [Accepted: 07/24/2014] [Indexed: 11/18/2022]
Abstract
MicroRNAs (miRNAs) are essential for regulation of gene expression. Though numerous miRNAs have been identified by high-throughput sequencing, few precursor miRNAs (pre-miRNAs) are experimentally validated. Here we report a strategy for constructing high-throughput sequencing libraries enriched for full-length pre-miRNAs. We find widespread and extensive uridylation of Argonaute (Ago)-bound pre-miRNAs, which is primarily catalyzed by two terminal uridylyltransferases: TUT7 and TUT4. Uridylation by TUT7/4 not only polishes pre-miRNA 3' ends, but also facilitates their degradation by the exosome, preventing clogging of Ago with defective species. We show that the exosome exploits distinct substrate preferences of DIS3 and RRP6, its two catalytic subunits, to distinguish productive from defective pre-miRNAs. Furthermore, we identify a positive feedback loop formed by the exosome and TUT7/4 in triggering uridylation and degradation of Ago-bound pre-miRNAs. Our study reveals a pre-miRNA surveillance system that comprises TUT7, TUT4, and the exosome in quality control of miRNA synthesis.
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Affiliation(s)
- Xuhang Liu
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; PENN Genome Frontiers Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Qi Zheng
- PENN Genome Frontiers Institute, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicholas Vrettos
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; PENN Genome Frontiers Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Manolis Maragkakis
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; PENN Genome Frontiers Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Panagiotis Alexiou
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; PENN Genome Frontiers Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Brian D Gregory
- PENN Genome Frontiers Institute, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zissimos Mourelatos
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; PENN Genome Frontiers Institute, University of Pennsylvania, Philadelphia, PA 19104, USA.
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134
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Leung E, Schneider C, Yan F, Mohi-El-Din H, Kudla G, Tuck A, Wlotzka W, Doronina VA, Bartley R, Watkins NJ, Tollervey D, Brown JD. Integrity of SRP RNA is ensured by La and the nuclear RNA quality control machinery. Nucleic Acids Res 2014; 42:10698-710. [PMID: 25159613 PMCID: PMC4176351 DOI: 10.1093/nar/gku761] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The RNA component of signal recognition particle (SRP) is transcribed by RNA polymerase III, and most steps in SRP biogenesis occur in the nucleolus. Here, we examine processing and quality control of the yeast SRP RNA (scR1). In common with other pol III transcripts, scR1 terminates in a U-tract, and mature scR1 retains a U4–5 sequence at its 3′ end. In cells lacking the exonuclease Rex1, scR1 terminates in a longer U5–6 tail that presumably represents the primary transcript. The 3′ U-tract of scR1 is protected from aberrant processing by the La homologue, Lhp1 and overexpressed Lhp1 apparently competes with both the RNA surveillance system and SRP assembly factors. Unexpectedly, the TRAMP and exosome nuclear RNA surveillance complexes are also implicated in protecting the 3′ end of scR1, which accumulates in the nucleolus of cells lacking the activities of these complexes. Misassembled scR1 has a primary degradation pathway in which Rrp6 acts early, followed by TRAMP-stimulated exonuclease degradation by the exosome. We conclude that the RNA surveillance machinery has key roles in both SRP biogenesis and quality control of the RNA, potentially facilitating the decision between these alternative fates.
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Affiliation(s)
- Eileen Leung
- RNA Biology Group and Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Claudia Schneider
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, UK
| | - Fu Yan
- RNA Biology Group and Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Hatem Mohi-El-Din
- RNA Biology Group and Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Grzegorz Kudla
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, UK
| | - Alex Tuck
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, UK
| | - Wiebke Wlotzka
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, UK
| | - Victoria A Doronina
- RNA Biology Group and Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Ralph Bartley
- RNA Biology Group and Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Nicholas J Watkins
- RNA Biology Group and Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - David Tollervey
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, UK
| | - Jeremy D Brown
- RNA Biology Group and Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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135
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Haddad N, Matos RG, Pinto T, Rannou P, Cappelier JM, Prévost H, Arraiano CM. The RNase R from Campylobacter jejuni has unique features and is involved in the first steps of infection. J Biol Chem 2014; 289:27814-24. [PMID: 25100732 DOI: 10.1074/jbc.m114.561795] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Bacterial pathogens must adapt/respond rapidly to changing environmental conditions. Ribonucleases (RNases) can be crucial factors contributing to the fast adaptation of RNA levels to different environmental demands. It has been demonstrated that the exoribonuclease polynucleotide phosphorylase (PNPase) facilitates survival of Campylobacter jejuni in low temperatures and favors swimming, chick colonization, and cell adhesion/invasion. However, little is known about the mechanism of action of other ribonucleases in this microorganism. Members of the RNB family of enzymes have been shown to be involved in virulence of several pathogens. We have searched C. jejuni genome for homologues and found one candidate that displayed properties more similar to RNase R (Cj-RNR). We show here that Cj-RNR is important for the first steps of infection, the adhesion and invasion of C. jejuni to eukaryotic cells. Moreover, Cj-RNR proved to be active in a wide range of conditions. The results obtained lead us to conclude that Cj-RNR has an important role in the biology of this foodborne pathogen.
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Affiliation(s)
- Nabila Haddad
- From the LUNAM Université, Oniris, University of Nantes, 44200 Nantes, France, the UMR1014 Sécurité des Aliments et Microbiologie, INRA, 44322 Nantes, France, and
| | - Rute G Matos
- the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av da República, 2780-157 Oeiras, Portugal
| | - Teresa Pinto
- the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av da República, 2780-157 Oeiras, Portugal
| | - Pauline Rannou
- From the LUNAM Université, Oniris, University of Nantes, 44200 Nantes, France, the UMR1014 Sécurité des Aliments et Microbiologie, INRA, 44322 Nantes, France, and
| | - Jean-Michel Cappelier
- From the LUNAM Université, Oniris, University of Nantes, 44200 Nantes, France, the UMR1014 Sécurité des Aliments et Microbiologie, INRA, 44322 Nantes, France, and
| | - Hervé Prévost
- From the LUNAM Université, Oniris, University of Nantes, 44200 Nantes, France, the UMR1014 Sécurité des Aliments et Microbiologie, INRA, 44322 Nantes, France, and
| | - Cecília M Arraiano
- the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av da República, 2780-157 Oeiras, Portugal
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136
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Faehnle CR, Walleshauser J, Joshua-Tor L. Mechanism of Dis3l2 substrate recognition in the Lin28-let-7 pathway. Nature 2014; 514:252-256. [PMID: 25119025 PMCID: PMC4192074 DOI: 10.1038/nature13553] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 06/02/2014] [Indexed: 12/28/2022]
Abstract
The pluripotency factor Lin28 inhibits the biogenesis of the let-7 family of mammalian microRNAs1–4. Lin28 is highly expressed in embryonic stem cells and has a fundamental role in regulation of development5, glucose metabolism6 and tissue regeneration7. Alternatively, Lin28 overexpression is correlated with the onset of numerous cancers8, while let-7, a tumor suppressor, silences several human oncogenes5. Lin28 binds to precursor let-7 (pre-let-7) hairpins9, triggering the 3' oligo-uridylation activity of TUT4/710–12. The oligoU tail added to pre-let-7 serves as a decay signal, as it is rapidly degraded by Dis3L213,14, a homolog of the catalytic subunit of the RNA exosome. The molecular basis of Lin28 mediated recruitment of TUT4/7 to pre-let-7 and its subsequent degradation by Dis3L2 is largely unknown. To examine the mechanism of Dis3L2 substrate recognition we determined the structure of mouse Dis3L2 in complex with an oligoU RNA to mimic the uridylated tail of pre-let-7. Three RNA binding domains form an open funnel on one face of the catalytic domain that allows RNA to navigate a path to the active site different from its exosome counterpart. The resulting path reveals an extensive network of uracil-specific interactions spanning the first twelve nucleotides of an oligoU-tailed RNA. We identify three U-specificity zones that explain how Dis3L2 recognizes, binds and processes uridylated pre-let-7 in the final step of the Lin28/let-7 pathway.
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Affiliation(s)
- Christopher R Faehnle
- W. M. Keck Structural Biology Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Cold Spring Harbor Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
| | - Jack Walleshauser
- W. M. Keck Structural Biology Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Watson School of Biological Science 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Cold Spring Harbor Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
| | - Leemor Joshua-Tor
- W. M. Keck Structural Biology Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Watson School of Biological Science 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Howard Hughes Medical Institute 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Cold Spring Harbor Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
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137
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Tsanova B, Spatrick P, Jacobson A, van Hoof A. The RNA exosome affects iron response and sensitivity to oxidative stress. RNA (NEW YORK, N.Y.) 2014; 20:1057-1067. [PMID: 24860016 PMCID: PMC4114685 DOI: 10.1261/rna.043257.113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 04/01/2014] [Indexed: 06/03/2023]
Abstract
RNA degradation plays important roles for maintaining temporal control and fidelity of gene expression, as well as processing of transcripts. In Saccharomyces cerevisiae the RNA exosome is a major 3'-to-5' exoribonuclease and also has an endonuclease domain of unknown function. Here we report a physiological role for the exosome in response to a stimulus. We show that inactivating the exoribonuclease active site of Rrp44 up-regulates the iron uptake regulon. This up-regulation is caused by increased levels of reactive oxygen species (ROS) in the mutant. Elevated ROS also causes hypersensitivity to H2O2, which can be reduced by the addition of iron to H2O2 stressed cells. Finally, we show that the previously characterized slow growth phenotype of rrp44-exo(-) is largely ameliorated during fermentative growth. While the molecular functions of Rrp44 and the RNA exosome have been extensively characterized, our studies characterize how this molecular function affects the physiology of the organism.
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Affiliation(s)
- Borislava Tsanova
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center–Houston and The University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77030, USA
| | - Phyllis Spatrick
- Department of Microbiology and Physiological Systems, Albert Sherman Center, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Allan Jacobson
- Department of Microbiology and Physiological Systems, Albert Sherman Center, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center–Houston and The University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77030, USA
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138
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Dedic E, Seweryn P, Jonstrup AT, Flygaard RK, Fedosova NU, Hoffmann SV, Boesen T, Brodersen DE. Structural analysis of the yeast exosome Rrp6p-Rrp47p complex by small-angle X-ray scattering. Biochem Biophys Res Commun 2014; 450:634-40. [PMID: 24937447 DOI: 10.1016/j.bbrc.2014.06.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 06/06/2014] [Indexed: 10/25/2022]
Abstract
The RNase D-type 3'-5' exonuclease Rrp6p from Saccharomyces cerevisiae is a nuclear-specific cofactor of the RNA exosome and associates in vivo with Rrp47p (Lrp1p). Here, we show using biochemistry and small-angle X-ray scattering (SAXS) that Rrp6p and Rrp47p associate into a stable, heterodimeric complex with an elongated shape consistent with binding of Rrp47p to the nuclease domain and opposite of the HRDC domain of Rrp6p. Rrp47p reduces the exonucleolytic activity of Rrp6p on both single-stranded and structured RNA substrates without significantly altering the affinity towards RNA or the ability of Rrp6p to degrade RNA secondary structure.
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Affiliation(s)
- Emil Dedic
- Centre for mRNP Biogenesis and Metabolism, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark; Department of Molecular Biology and Genetics, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Paulina Seweryn
- Centre for mRNP Biogenesis and Metabolism, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark; Department of Molecular Biology and Genetics, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Anette Thyssen Jonstrup
- Centre for mRNP Biogenesis and Metabolism, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark; Department of Molecular Biology and Genetics, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Rasmus Koch Flygaard
- Centre for mRNP Biogenesis and Metabolism, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark; Department of Molecular Biology and Genetics, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Natalya U Fedosova
- Department of Biomedicine, Ole Worms Allé 6, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Søren Vrønning Hoffmann
- Institute for Storage Ring Facilities (ISA), Department of Physics and Astronomy, Ny Munkegade 120, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Thomas Boesen
- Centre for Membrane Pumps in Cells and Disease - PUMPKIN, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark; Department of Molecular Biology and Genetics, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Ditlev Egeskov Brodersen
- Centre for mRNP Biogenesis and Metabolism, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark; Department of Molecular Biology and Genetics, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark.
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139
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Niemelä EH, Oghabian A, Staals RHJ, Greco D, Pruijn GJM, Frilander MJ. Global analysis of the nuclear processing of transcripts with unspliced U12-type introns by the exosome. Nucleic Acids Res 2014; 42:7358-69. [PMID: 24848017 PMCID: PMC4066798 DOI: 10.1093/nar/gku391] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
U12-type introns are a rare class of introns in the genomes of diverse eukaryotes. In the human genome, they number over 700. A subset of these introns has been shown to be spliced at a slower rate compared to the major U2-type introns. This suggests a rate-limiting regulatory function for the minor spliceosome in the processing of transcripts containing U12-type introns. However, both the generality of slower splicing and the subsequent fate of partially processed pre-mRNAs remained unknown. Here, we present a global analysis of the nuclear retention of transcripts containing U12-type introns and provide evidence for the nuclear decay of such transcripts in human cells. Using SOLiD RNA sequencing technology, we find that, in normal cells, U12-type introns are on average 2-fold more retained than the surrounding U2-type introns. Furthermore, we find that knockdown of RRP41 and DIS3 subunits of the exosome stabilizes an overlapping set of U12-type introns. RRP41 knockdown leads to slower decay kinetics of U12-type introns and globally upregulates the retention of U12-type, but not U2-type, introns. Our results indicate that U12-type introns are spliced less efficiently and are targeted by the exosome. These characteristics support their role in the regulation of cellular mRNA levels.
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Affiliation(s)
- Elina H Niemelä
- Institute of Biotechnology, P.O. Box 56, FI-00014 University of Helsinki, Finland
| | - Ali Oghabian
- Institute of Biotechnology, P.O. Box 56, FI-00014 University of Helsinki, Finland
| | - Raymond H J Staals
- Department of Biomolecular Chemistry, Radboud Institute for Molecular Life Sciences and Institute for Molecules and Materials, Radboud University Nijmegen,The Netherlands
| | - Dario Greco
- Unit of Systems Toxicology, Finnish Institute of Occupational Health, Topeliuksenkatu 41 a A, FI-00250 Helsinki, Finland
| | - Ger J M Pruijn
- Department of Biomolecular Chemistry, Radboud Institute for Molecular Life Sciences and Institute for Molecules and Materials, Radboud University Nijmegen,The Netherlands
| | - Mikko J Frilander
- Institute of Biotechnology, P.O. Box 56, FI-00014 University of Helsinki, Finland
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140
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The C-terminal domain from S. cerevisiae Pat1 displays two conserved regions involved in decapping factor recruitment. PLoS One 2014; 9:e96828. [PMID: 24830408 PMCID: PMC4022514 DOI: 10.1371/journal.pone.0096828] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 04/11/2014] [Indexed: 12/03/2022] Open
Abstract
Eukaryotic mRNA decay is a highly regulated process allowing cells to rapidly modulate protein production in response to internal and environmental cues. Mature translatable eukaryotic mRNAs are protected from fast and uncontrolled degradation in the cytoplasm by two cis-acting stability determinants: a methylguanosine (m7G) cap and a poly(A) tail at their 5′ and 3′ extremities, respectively. The hydrolysis of the m7G cap structure, known as decapping, is performed by the complex composed of the Dcp2 catalytic subunit and its partner Dcp1. The Dcp1-Dcp2 decapping complex has a low intrinsic activity and requires accessory factors to be fully active. Among these factors, Pat1 is considered to be a central scaffolding protein involved in Dcp2 activation but also in inhibition of translation initiation. Here, we present the structural and functional study of the C-terminal domain from S. cerevisiae Pat1 protein. We have identified two conserved and functionally important regions located at both extremities of the domain. The first region is involved in binding to Lsm1-7 complex. The second patch is specific for fungal proteins and is responsible for Pat1 interaction with Edc3. These observations support the plasticity of the protein interaction network involved in mRNA decay and show that evolution has extended the C-terminal alpha-helical domain from fungal Pat1 proteins to generate a new binding platform for protein partners.
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141
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Liu H, Luo M, Wen JK. mRNA stability in the nucleus. J Zhejiang Univ Sci B 2014; 15:444-54. [PMID: 24793762 PMCID: PMC4076601 DOI: 10.1631/jzus.b1400088] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 04/11/2014] [Indexed: 01/15/2023]
Abstract
Eukaryotic gene expression is controlled by different levels of biological events, such as transcription factors regulating the timing and strength of transcripts production, alteration of transcription rate by RNA processing, and mRNA stability during RNA processing and translation. RNAs, especially mRNAs, are relatively vulnerable molecules in living cells for ribonucleases (RNases). The maintenance of quality and quantity of transcripts is a key issue for many biological processes. Extensive studies draw the conclusion that the stability of RNAs is dedicated-regulated, occurring co- and post-transcriptionally, and translation-coupled as well, either in the nucleus or cytoplasm. Recently, RNA stability in the nucleus has aroused much research interest, especially the stability of newly-made transcripts. In this article, we summarize recent progresses on mRNA stability in the nucleus, especially focusing on quality control of newly-made RNA by RNA polymerase II in eukaryotes.
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Affiliation(s)
- Han Liu
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian 116044, China
| | - Min Luo
- Chongqing Institute of Tuberculosis Prevention and Treatment, Chongqing 400050, China
| | - Ji-kai Wen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
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142
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Evguenieva-Hackenberg E, Hou L, Glaeser S, Klug G. Structure and function of the archaeal exosome. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 5:623-35. [DOI: 10.1002/wrna.1234] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/28/2014] [Accepted: 03/06/2014] [Indexed: 11/10/2022]
Affiliation(s)
| | - Linlin Hou
- Institute of Microbiology and Molecular Biology; University of Giessen; Giessen Germany
| | - Stefanie Glaeser
- Institute of Applied Microbiology; University of Giessen; Giessen Germany
| | - Gabriele Klug
- Institute of Microbiology and Molecular Biology; University of Giessen; Giessen Germany
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143
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The genetic architecture of multiple myeloma. Adv Hematol 2014; 2014:864058. [PMID: 24803933 PMCID: PMC3996928 DOI: 10.1155/2014/864058] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 02/16/2014] [Indexed: 11/18/2022] Open
Abstract
Multiple myeloma is a malignant proliferation of monoclonal plasma cells leading to clinical features that include hypercalcaemia, renal dysfunction, anaemia, and bone disease (frequently referred to by the acronym CRAB) which represent evidence of end organ failure. Recent evidence has revealed myeloma to be a highly heterogeneous disease composed of multiple molecularly-defined subtypes each with varying clinicopathological features and disease outcomes. The major division within myeloma is between hyperdiploid and nonhyperdiploid subtypes. In this division, hyperdiploid myeloma is characterised by trisomies of certain odd numbered chromosomes, namely, 3, 5, 7, 9, 11, 15, 19, and 21 whereas nonhyperdiploid myeloma is characterised by translocations of the immunoglobulin heavy chain alleles at chromosome 14q32 with various partner chromosomes, the most important of which being 4, 6, 11, 16, and 20. Hyperdiploid and nonhyperdiploid changes appear to represent early or even initiating mutagenic events that are subsequently followed by secondary aberrations including copy number abnormalities, additional translocations, mutations, and epigenetic modifications which lead to plasma cell immortalisation and disease progression. The following review provides a comprehensive coverage of the genetic and epigenetic events contributing to the initiation and progression of multiple myeloma and where possible these abnormalities have been linked to disease prognosis.
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144
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Barbosa RL, Legrand P, Wien F, Pineau B, Thompson A, Guimarães BG. RRP6 from Trypanosoma brucei: crystal structure of the catalytic domain, association with EAP3 and activity towards structured and non-structured RNA substrates. PLoS One 2014; 9:e89138. [PMID: 24558481 PMCID: PMC3928423 DOI: 10.1371/journal.pone.0089138] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 01/20/2014] [Indexed: 11/19/2022] Open
Abstract
RRP6 is a 3′–5′ exoribonuclease associated to the eukaryotic exosome, a multiprotein complex essential for various RNA processing and degradation pathways. In Trypanosoma brucei, RRP6 associates with the exosome in stoichiometric amounts and was localized in both cytoplasm and nucleus, in contrast to yeast Rrp6 which is exclusively nuclear. Here we report the biochemical and structural characterization of T. brucei RRP6 (TbRRP6) and its interaction with the so-called T. brucei Exosome Associated Protein 3 (TbEAP3), a potential orthologue of the yeast Rrp6 interacting protein, Rrp47. Recombinant TbEAP3 is a thermo stable homodimer in solution, however it forms a heterodimeric complex with TbRRP6 with 1∶1 stoichiometry. The crystallographic structure of the TbRRP6 catalytic core exposes for the first time the native catalytic site of this RNase and also reveals a disulfide bond linking two helices of the HRDC domain. RNA degradation assays show the distributive exoribonuclease activity of TbRRP6 and novel findings regarding the structural range of its RNA substrates. TbRRP6 was able to degrade single and double-stranded RNAs and also RNA substrates containing stem-loops including those with 3′ stem-loop lacking single-stranded extensions. Finally, association with TbEAP3 did not significantly interfere with the TbRRP6 catalytic activity in vitro.
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Affiliation(s)
| | | | - Frank Wien
- Synchrotron SOLEIL, Gif-sur Yvette, France
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145
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Januszyk K, Lima CD. The eukaryotic RNA exosome. Curr Opin Struct Biol 2014; 24:132-40. [PMID: 24525139 DOI: 10.1016/j.sbi.2014.01.011] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 01/15/2014] [Accepted: 01/16/2014] [Indexed: 12/24/2022]
Abstract
The eukaryotic RNA exosome is an essential multi-subunit ribonuclease complex that contributes to the degradation or processing of nearly every class of RNA in both the nucleus and cytoplasm. Its nine-subunit core shares structural similarity to phosphorolytic exoribonucleases such as bacterial PNPase. PNPase and the RNA exosome core feature a central channel that can accommodate single stranded RNA although unlike PNPase, the RNA exosome core is devoid of ribonuclease activity. Instead, the core associates with Rrp44, an endoribonuclease and processive 3'→5' exoribonuclease, and Rrp6, a distributive 3'→5' exoribonuclease. Recent biochemical and structural studies suggest that the exosome core is essential because it coordinates Rrp44 and Rrp6 recruitment, RNA can pass through the central channel, and the association with the core modulates Rrp44 and Rrp6 activities.
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Affiliation(s)
- Kurt Januszyk
- Structural Biology Program, Sloan-Kettering Institute, 1275 York Avenue, NY, USA
| | - Christopher D Lima
- Structural Biology Program, Sloan-Kettering Institute, 1275 York Avenue, NY, USA; Howard Hughes Medical Institute, Structural Biology Program, Sloan-Kettering Institute, 1275 York Avenue, NY, USA.
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146
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147
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Liu JJ, Bratkowski MA, Liu X, Niu CY, Ke A, Wang HW. Visualization of distinct substrate-recruitment pathways in the yeast exosome by EM. Nat Struct Mol Biol 2013; 21:95-102. [PMID: 24336220 PMCID: PMC3976988 DOI: 10.1038/nsmb.2736] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Accepted: 11/06/2013] [Indexed: 12/25/2022]
Abstract
The eukaryotic exosome is a multi-subunit complex typically composed of a catalytically inactive core and the Rrp44 protein, which contains 3’ to 5’ exo- and endo-ribonuclease activities. RNA substrates have been shown to be recruited through the core to reach Rrp44's exoribonuclease (EXO) site. Using single particle electron microscopy and biochemical analysis, we provide visual evidence that two distinct substrate recruitment pathways exist. In the through-core route, channeling of the single stranded substrates from the core to Rrp44 induces a characteristic conformational change in Rrp44. In the alternative direct-access route, this conformational change does not take place and the RNA substrate is visualized to avoid the core and enter Rrp44's EXO site directly. Our results provide mechanistic explanations for several RNA processing scenarios by the eukaryotic exosome and indicate substrate specific modes of degradation by this complex.
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Affiliation(s)
- Jun-Jie Liu
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.,Joint Graduate Program of Peking-Tsinghua-NBIS, Tsinghua University, Beijing 100084, China
| | - Matthew A Bratkowski
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Xueqi Liu
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Chu-Ya Niu
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Ailong Ke
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Hong-Wei Wang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.,Joint Graduate Program of Peking-Tsinghua-NBIS, Tsinghua University, Beijing 100084, China
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148
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Ustianenko D, Hrossova D, Potesil D, Chalupnikova K, Hrazdilova K, Pachernik J, Cetkovska K, Uldrijan S, Zdrahal Z, Vanacova S. Mammalian DIS3L2 exoribonuclease targets the uridylated precursors of let-7 miRNAs. RNA (NEW YORK, N.Y.) 2013; 19:1632-8. [PMID: 24141620 PMCID: PMC3884668 DOI: 10.1261/rna.040055.113] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 08/27/2013] [Indexed: 05/23/2023]
Abstract
The mechanisms of gene expression regulation by miRNAs have been extensively studied. However, the regulation of miRNA function and decay has long remained enigmatic. Only recently, 3' uridylation via LIN28A-TUT4/7 has been recognized as an essential component controlling the biogenesis of let-7 miRNAs in stem cells. Although uridylation has been generally implicated in miRNA degradation, the nuclease responsible has remained unknown. Here, we identify the Perlman syndrome-associated protein DIS3L2 as an oligo(U)-binding and processing exoribonuclease that specifically targets uridylated pre-let-7 in vivo. This study establishes DIS3L2 as the missing component of the LIN28-TUT4/7-DIS3L2 pathway required for the repression of let-7 in pluripotent cells.
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Affiliation(s)
- Dmytro Ustianenko
- CEITEC-Central European Institute of Technology, Masaryk University, 625 00, Brno, Czech Republic
| | - Dominika Hrossova
- CEITEC-Central European Institute of Technology, Masaryk University, 625 00, Brno, Czech Republic
| | - David Potesil
- CEITEC-Central European Institute of Technology, Masaryk University, 625 00, Brno, Czech Republic
| | - Katerina Chalupnikova
- CEITEC-Central European Institute of Technology, Masaryk University, 625 00, Brno, Czech Republic
| | - Kristyna Hrazdilova
- CEITEC-Central European Institute of Technology, Masaryk University, 625 00, Brno, Czech Republic
| | - Jiri Pachernik
- Department of Experimental Biology, Faculty of Science, Masaryk University, 611 37, Brno, Czech Republic
| | - Katerina Cetkovska
- Department of Biology, Faculty of Medicine, Masaryk University, 625 00, Brno, Czech Republic
| | - Stjepan Uldrijan
- Department of Biology, Faculty of Medicine, Masaryk University, 625 00, Brno, Czech Republic
| | - Zbynek Zdrahal
- CEITEC-Central European Institute of Technology, Masaryk University, 625 00, Brno, Czech Republic
| | - Stepanka Vanacova
- CEITEC-Central European Institute of Technology, Masaryk University, 625 00, Brno, Czech Republic
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149
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Lourenço RF, Leme AFP, Oliveira CC. Proteomic Analysis of Yeast Mutant RNA Exosome Complexes. J Proteome Res 2013; 12:5912-22. [DOI: 10.1021/pr400972x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rogério F. Lourenço
- Department
of Biochemistry, Chemistry Institute, University of São Paulo, Av. Prof. Lineu Prestes 748, 05508-000 São Paulo, Brazil
| | - Adriana F. P. Leme
- Mass
Spectrometry Laboratory, Brazilian Biosciences National Laboratory- CNPEM, R. Giuseppe Máximo Scolfaro 10000, 13083-970 Campinas, Brazil
| | - Carla C. Oliveira
- Department
of Biochemistry, Chemistry Institute, University of São Paulo, Av. Prof. Lineu Prestes 748, 05508-000 São Paulo, Brazil
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150
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Reis FP, Barbas A, Klauer-King AA, Tsanova B, Schaeffer D, López-Viñas E, Gómez-Puertas P, van Hoof A, Arraiano CM. Modulating the RNA processing and decay by the exosome: altering Rrp44/Dis3 activity and end-product. PLoS One 2013; 8:e76504. [PMID: 24265673 PMCID: PMC3827031 DOI: 10.1371/journal.pone.0076504] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 08/27/2013] [Indexed: 01/02/2023] Open
Abstract
In eukaryotes, the exosome plays a central role in RNA maturation, turnover, and quality control. In Saccharomyces cerevisiae, the core exosome is composed of nine catalytically inactive subunits constituting a ring structure and the active nuclease Rrp44, also known as Dis3. Rrp44 is a member of the ribonuclease II superfamily of exoribonucleases which include RNase R, Dis3L1 and Dis3L2. In this work we have functionally characterized three residues located in the highly conserved RNB catalytic domain of Rrp44: Y595, Q892 and G895. To address their precise role in Rrp44 activity, we have constructed Rrp44 mutants and compared their activity to the wild-type Rrp44. When we mutated residue Q892 and tested its activity in vitro, the enzyme became slightly more active. We also showed that when we mutated Y595, the final degradation product of Rrp44 changed from 4 to 5 nucleotides. This result confirms that this residue is responsible for the stacking of the RNA substrate in the catalytic cavity, as was predicted from the structure of Rrp44. Furthermore, we also show that a strain with a mutation in this residue has a growth defect and affects RNA processing and degradation. These results lead us to hypothesize that this residue has an important biological role. Molecular dynamics modeling of these Rrp44 mutants and the wild-type enzyme showed changes that extended beyond the mutated residues and helped to explain these results.
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Affiliation(s)
- Filipa P. Reis
- Instituto de Tecnologia Química e Biológica - ITQB, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ana Barbas
- Instituto de Tecnologia Química e Biológica - ITQB, Universidade Nova de Lisboa, Oeiras, Portugal
| | - A. A. Klauer-King
- Department of Microbiology and Molecular Genetics, and The University of Texas Graduate School of Biomedical Sciences, University of Texas Health Science Center-Houston, Houston, Texas, United States of America
| | - Borislava Tsanova
- Department of Microbiology and Molecular Genetics, and The University of Texas Graduate School of Biomedical Sciences, University of Texas Health Science Center-Houston, Houston, Texas, United States of America
| | - Daneen Schaeffer
- Department of Microbiology and Molecular Genetics, and The University of Texas Graduate School of Biomedical Sciences, University of Texas Health Science Center-Houston, Houston, Texas, United States of America
| | - Eduardo López-Viñas
- Centro de Biologia Molecular “Severo Ochoa” (CSIC-UAM), Campus Universidad Autonoma de Madrid, Madrid, Spain
- Biomol-Informatics SL, Madrid, Spain
| | - Paulino Gómez-Puertas
- Centro de Biologia Molecular “Severo Ochoa” (CSIC-UAM), Campus Universidad Autonoma de Madrid, Madrid, Spain
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, and The University of Texas Graduate School of Biomedical Sciences, University of Texas Health Science Center-Houston, Houston, Texas, United States of America
| | - Cecília M. Arraiano
- Instituto de Tecnologia Química e Biológica - ITQB, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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