1
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Cheng Y, Wang S, Zhang H, Lee JS, Ni C, Guo J, Chen E, Wang S, Acharya A, Chang TC, Buszczak M, Zhu H, Mendell JT. A non-canonical role for a small nucleolar RNA in ribosome biogenesis and senescence. Cell 2024; 187:4770-4789.e23. [PMID: 38981482 PMCID: PMC11344685 DOI: 10.1016/j.cell.2024.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 02/20/2024] [Accepted: 06/12/2024] [Indexed: 07/11/2024]
Abstract
Cellular senescence is an irreversible state of cell-cycle arrest induced by various stresses, including aberrant oncogene activation, telomere shortening, and DNA damage. Through a genome-wide screen, we discovered a conserved small nucleolar RNA (snoRNA), SNORA13, that is required for multiple forms of senescence in human cells and mice. Although SNORA13 guides the pseudouridylation of a conserved nucleotide in the ribosomal decoding center, loss of this snoRNA minimally impacts translation. Instead, we found that SNORA13 negatively regulates ribosome biogenesis. Senescence-inducing stress perturbs ribosome biogenesis, resulting in the accumulation of free ribosomal proteins (RPs) that trigger p53 activation. SNORA13 interacts directly with RPL23, decreasing its incorporation into maturing 60S subunits and, consequently, increasing the pool of free RPs, thereby promoting p53-mediated senescence. Thus, SNORA13 regulates ribosome biogenesis and the p53 pathway through a non-canonical mechanism distinct from its role in guiding RNA modification. These findings expand our understanding of snoRNA functions and their roles in cellular signaling.
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Affiliation(s)
- Yujing Cheng
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Siwen Wang
- Division of Vascular Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou 510080, Guangdong, China; National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou 510080, Guangdong, China
| | - He Zhang
- Quantitative Biomedical Research Center, Peter O'Donnell Jr. School of Public Health, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jong-Sun Lee
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chunyang Ni
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jason Guo
- Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Eric Chen
- Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shenming Wang
- Division of Vascular Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou 510080, Guangdong, China; National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou 510080, Guangdong, China
| | - Asha Acharya
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tsung-Cheng Chang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael Buszczak
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Hao Zhu
- Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Joshua T Mendell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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2
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Dörner K, Ruggeri C, Zemp I, Kutay U. Ribosome biogenesis factors-from names to functions. EMBO J 2023; 42:e112699. [PMID: 36762427 PMCID: PMC10068337 DOI: 10.15252/embj.2022112699] [Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/13/2022] [Accepted: 01/19/2023] [Indexed: 02/11/2023] Open
Abstract
The assembly of ribosomal subunits is a highly orchestrated process that involves a huge cohort of accessory factors. Most eukaryotic ribosome biogenesis factors were first identified by genetic screens and proteomic approaches of pre-ribosomal particles in Saccharomyces cerevisiae. Later, research on human ribosome synthesis not only demonstrated that the requirement for many of these factors is conserved in evolution, but also revealed the involvement of additional players, reflecting a more complex assembly pathway in mammalian cells. Yet, it remained a challenge for the field to assign a function to many of the identified factors and to reveal their molecular mode of action. Over the past decade, structural, biochemical, and cellular studies have largely filled this gap in knowledge and led to a detailed understanding of the molecular role that many of the players have during the stepwise process of ribosome maturation. Such detailed knowledge of the function of ribosome biogenesis factors will be key to further understand and better treat diseases linked to disturbed ribosome assembly, including ribosomopathies, as well as different types of cancer.
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Affiliation(s)
- Kerstin Dörner
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, Zurich, Switzerland
| | - Chiara Ruggeri
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.,RNA Biology Ph.D. Program, Zurich, Switzerland
| | - Ivo Zemp
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Ulrike Kutay
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
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3
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McCown PJ, Ruszkowska A, Kunkler CN, Breger K, Hulewicz JP, Wang MC, Springer NA, Brown JA. Naturally occurring modified ribonucleosides. WILEY INTERDISCIPLINARY REVIEWS. RNA 2020; 11:e1595. [PMID: 32301288 PMCID: PMC7694415 DOI: 10.1002/wrna.1595] [Citation(s) in RCA: 96] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 03/09/2020] [Accepted: 03/11/2020] [Indexed: 12/18/2022]
Abstract
The chemical identity of RNA molecules beyond the four standard ribonucleosides has fascinated scientists since pseudouridine was characterized as the "fifth" ribonucleotide in 1951. Since then, the ever-increasing number and complexity of modified ribonucleosides have been found in viruses and throughout all three domains of life. Such modifications can be as simple as methylations, hydroxylations, or thiolations, complex as ring closures, glycosylations, acylations, or aminoacylations, or unusual as the incorporation of selenium. While initially found in transfer and ribosomal RNAs, modifications also exist in messenger RNAs and noncoding RNAs. Modifications have profound cellular outcomes at various levels, such as altering RNA structure or being essential for cell survival or organism viability. The aberrant presence or absence of RNA modifications can lead to human disease, ranging from cancer to various metabolic and developmental illnesses such as Hoyeraal-Hreidarsson syndrome, Bowen-Conradi syndrome, or Williams-Beuren syndrome. In this review article, we summarize the characterization of all 143 currently known modified ribonucleosides by describing their taxonomic distributions, the enzymes that generate the modifications, and any implications in cellular processes, RNA structure, and disease. We also highlight areas of active research, such as specific RNAs that contain a particular type of modification as well as methodologies used to identify novel RNA modifications. This article is categorized under: RNA Processing > RNA Editing and Modification.
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Affiliation(s)
- Phillip J. McCown
- Department of Chemistry and BiochemistryUniversity of Notre DameNotre DameIndianaUSA
| | - Agnieszka Ruszkowska
- Department of Chemistry and BiochemistryUniversity of Notre DameNotre DameIndianaUSA
- Present address:
Institute of Bioorganic ChemistryPolish Academy of SciencesPoznanPoland
| | - Charlotte N. Kunkler
- Department of Chemistry and BiochemistryUniversity of Notre DameNotre DameIndianaUSA
| | - Kurtis Breger
- Department of Chemistry and BiochemistryUniversity of Notre DameNotre DameIndianaUSA
| | - Jacob P. Hulewicz
- Department of Chemistry and BiochemistryUniversity of Notre DameNotre DameIndianaUSA
| | - Matthew C. Wang
- Department of Chemistry and BiochemistryUniversity of Notre DameNotre DameIndianaUSA
| | - Noah A. Springer
- Department of Chemistry and BiochemistryUniversity of Notre DameNotre DameIndianaUSA
| | - Jessica A. Brown
- Department of Chemistry and BiochemistryUniversity of Notre DameNotre DameIndianaUSA
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4
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Meyer B, Immer C, Kaiser S, Sharma S, Yang J, Watzinger P, Weiß L, Kotter A, Helm M, Seitz HM, Kötter P, Kellner S, Entian KD, Wöhnert J. Identification of the 3-amino-3-carboxypropyl (acp) transferase enzyme responsible for acp3U formation at position 47 in Escherichia coli tRNAs. Nucleic Acids Res 2020; 48:1435-1450. [PMID: 31863583 PMCID: PMC7026641 DOI: 10.1093/nar/gkz1191] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 02/06/2023] Open
Abstract
tRNAs from all domains of life contain modified nucleotides. However, even for the experimentally most thoroughly characterized model organism Escherichia coli not all tRNA modification enzymes are known. In particular, no enzyme has been found yet for introducing the acp3U modification at position 47 in the variable loop of eight E. coli tRNAs. Here we identify the so far functionally uncharacterized YfiP protein as the SAM-dependent 3-amino-3-carboxypropyl transferase catalyzing this modification and thereby extend the list of known tRNA modification enzymes in E. coli. Similar to the Tsr3 enzymes that introduce acp modifications at U or m1Ψ nucleotides in rRNAs this protein contains a DTW domain suggesting that acp transfer reactions to RNA nucleotides are a general function of DTW domain containing proteins. The introduction of the acp3U-47 modification in E. coli tRNAs is promoted by the presence of the m7G-46 modification as well as by growth in rich medium. However, a deletion of the enzymes responsible for the modifications at position 46 and 47 in the variable loop of E. coli tRNAs did not lead to a clearly discernible phenotype suggesting that these two modifications play only a minor role in ensuring the proper function of tRNAs in E. coli.
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Affiliation(s)
- Britta Meyer
- Institute for Molecular Biosciences, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M., Germany
| | - Carina Immer
- Institute for Molecular Biosciences, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M., Germany
| | - Steffen Kaiser
- Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstr. 5, 81377 Munich, Germany
| | - Sunny Sharma
- Institute for Molecular Biosciences, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M., Germany.,Department of Cell Biology and Neurosciences, Rutgers University, Piscataway, NJ 08854, USA
| | - Jun Yang
- Institute for Molecular Biosciences, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M., Germany.,Department of Cell Biology and Neurosciences, Rutgers University, Piscataway, NJ 08854, USA
| | - Peter Watzinger
- Institute for Molecular Biosciences, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M., Germany
| | - Lena Weiß
- Institute for Molecular Biosciences, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M., Germany
| | - Annika Kotter
- Institute of Pharmacy and Biochemistry, Johannes-Gutenberg-Universität Mainz, Staudingerweg 5, 55128 Mainz, Germany
| | - Mark Helm
- Institute of Pharmacy and Biochemistry, Johannes-Gutenberg-Universität Mainz, Staudingerweg 5, 55128 Mainz, Germany
| | - Hans-Michael Seitz
- Institute for Geosciences, Research Unit Mineralogy, and Frankfurt Isotope and Element Research Center (FIERCE), Goethe-Universität Frankfurt, Altenhöferallee 1, 60438 Frankfurt/M., Germany
| | - Peter Kötter
- Institute for Molecular Biosciences, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M., Germany
| | - Stefanie Kellner
- Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstr. 5, 81377 Munich, Germany
| | - Karl-Dieter Entian
- Institute for Molecular Biosciences, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M., Germany
| | - Jens Wöhnert
- Institute for Molecular Biosciences, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M., Germany.,Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M., Germany
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5
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Sergiev PV, Aleksashin NA, Chugunova AA, Polikanov YS, Dontsova OA. Structural and evolutionary insights into ribosomal RNA methylation. Nat Chem Biol 2019; 14:226-235. [PMID: 29443970 DOI: 10.1038/nchembio.2569] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 01/02/2018] [Indexed: 01/24/2023]
Abstract
Methylation of nucleotides in ribosomal RNAs (rRNAs) is a ubiquitous feature that occurs in all living organisms. Identification of all enzymes responsible for rRNA methylation, as well as mapping of all modified rRNA residues, is now complete for a number of model species, such as Escherichia coli and Saccharomyces cerevisiae. Recent high-resolution structures of bacterial ribosomes provided the first direct visualization of methylated nucleotides. The structures of ribosomes from various organisms and organelles have also lately become available, enabling comparative structure-based analysis of rRNA methylation sites in various taxonomic groups. In addition to the conserved core of modified residues in ribosomes from the majority of studied organisms, structural analysis points to the functional roles of some of the rRNA methylations, which are discussed in this Review in an evolutionary context.
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Affiliation(s)
- Petr V Sergiev
- Skolkovo Institute of Science and Technology, Skolkovo, Moscow Region, Russia.,Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia.,A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Nikolay A Aleksashin
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Anastasia A Chugunova
- Skolkovo Institute of Science and Technology, Skolkovo, Moscow Region, Russia.,Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia
| | - Yury S Polikanov
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Olga A Dontsova
- Skolkovo Institute of Science and Technology, Skolkovo, Moscow Region, Russia.,Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia.,A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
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6
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Henras AK, Plisson-Chastang C, Humbert O, Romeo Y, Henry Y. Synthesis, Function, and Heterogeneity of snoRNA-Guided Posttranscriptional Nucleoside Modifications in Eukaryotic Ribosomal RNAs. Enzymes 2017; 41:169-213. [PMID: 28601222 DOI: 10.1016/bs.enz.2017.03.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Ribosomal RNAs contain numerous 2'-O-methylated nucleosides and pseudouridines. Methylation of the 2' oxygen of ribose moieties and isomerization of uridines into pseudouridines are catalyzed by C/D and H/ACA small nucleolar ribonucleoprotein particles, respectively. We review the composition, structure, and mode of action of archaeal and eukaryotic C/D and H/ACA particles. Most rRNA modifications cluster in functionally crucial regions of the rRNAs, suggesting they play important roles in translation. Some of these modifications promote global translation efficiency or modulate translation fidelity. Strikingly, recent quantitative nucleoside modification profiling methods have revealed that a subset of modification sites is not always fully modified. The finding of such ribosome heterogeneity is in line with the concept of specialized ribosomes that could preferentially translate specific mRNAs. This emerging concept is supported by findings that some human diseases are caused by defects in the rRNA modification machinery correlated with a significant alteration of IRES-dependent translation.
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Affiliation(s)
- Anthony K Henras
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France.
| | - Célia Plisson-Chastang
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Odile Humbert
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Yves Romeo
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Yves Henry
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France.
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7
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Meyer B, Wurm JP, Sharma S, Immer C, Pogoryelov D, Kötter P, Lafontaine DLJ, Wöhnert J, Entian KD. Ribosome biogenesis factor Tsr3 is the aminocarboxypropyl transferase responsible for 18S rRNA hypermodification in yeast and humans. Nucleic Acids Res 2016; 44:4304-16. [PMID: 27084949 PMCID: PMC4872110 DOI: 10.1093/nar/gkw244] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 03/28/2016] [Indexed: 12/15/2022] Open
Abstract
The chemically most complex modification in eukaryotic rRNA is the conserved hypermodified nucleotide N1-methyl-N3-aminocarboxypropyl-pseudouridine (m(1)acp(3)Ψ) located next to the P-site tRNA on the small subunit 18S rRNA. While S-adenosylmethionine was identified as the source of the aminocarboxypropyl (acp) group more than 40 years ago the enzyme catalyzing the acp transfer remained elusive. Here we identify the cytoplasmic ribosome biogenesis protein Tsr3 as the responsible enzyme in yeast and human cells. In functionally impaired Tsr3-mutants, a reduced level of acp modification directly correlates with increased 20S pre-rRNA accumulation. The crystal structure of archaeal Tsr3 homologs revealed the same fold as in SPOUT-class RNA-methyltransferases but a distinct SAM binding mode. This unique SAM binding mode explains why Tsr3 transfers the acp and not the methyl group of SAM to its substrate. Structurally, Tsr3 therefore represents a novel class of acp transferase enzymes.
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Affiliation(s)
- Britta Meyer
- Institute for Molecular Biosciences, Goethe University, Frankfurt/M, Germany
| | - Jan Philip Wurm
- Institute for Molecular Biosciences, Goethe University, Frankfurt/M, Germany Center of Biomolecular Magnetic Resonance, Goethe University, Frankfurt/M, Germany
| | - Sunny Sharma
- RNA Molecular Biology & Center for Microscopy and Molecular Imaging, Fonds National de la Recherche Scientifique (F.R.S./FNRS), Université Libre de Bruxelles (ULB)
| | - Carina Immer
- Institute for Molecular Biosciences, Goethe University, Frankfurt/M, Germany Center of Biomolecular Magnetic Resonance, Goethe University, Frankfurt/M, Germany
| | - Denys Pogoryelov
- Institute of Biochemistry, Goethe University, Frankfurt/M, Germany
| | - Peter Kötter
- Institute for Molecular Biosciences, Goethe University, Frankfurt/M, Germany
| | - Denis L J Lafontaine
- RNA Molecular Biology & Center for Microscopy and Molecular Imaging, Fonds National de la Recherche Scientifique (F.R.S./FNRS), Université Libre de Bruxelles (ULB)
| | - Jens Wöhnert
- Institute for Molecular Biosciences, Goethe University, Frankfurt/M, Germany Center of Biomolecular Magnetic Resonance, Goethe University, Frankfurt/M, Germany
| | - Karl-Dieter Entian
- Institute for Molecular Biosciences, Goethe University, Frankfurt/M, Germany
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8
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Meyer B, Wurm JP, Kötter P, Leisegang MS, Schilling V, Buchhaupt M, Held M, Bahr U, Karas M, Heckel A, Bohnsack MT, Wöhnert J, Entian KD. The Bowen-Conradi syndrome protein Nep1 (Emg1) has a dual role in eukaryotic ribosome biogenesis, as an essential assembly factor and in the methylation of Ψ1191 in yeast 18S rRNA. Nucleic Acids Res 2010; 39:1526-37. [PMID: 20972225 PMCID: PMC3045603 DOI: 10.1093/nar/gkq931] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The Nep1 (Emg1) SPOUT-class methyltransferase is an essential ribosome assembly factor and the human Bowen–Conradi syndrome (BCS) is caused by a specific Nep1D86G mutation. We recently showed in vitro that Methanocaldococcus jannaschii Nep1 is a sequence-specific pseudouridine-N1-methyltransferase. Here, we show that in yeast the in vivo target site for Nep1-catalyzed methylation is located within loop 35 of the 18S rRNA that contains the unique hypermodification of U1191 to 1-methyl-3-(3-amino-3-carboxypropyl)-pseudouri-dine (m1acp3Ψ). Specific 14C-methionine labelling of 18S rRNA in yeast mutants showed that Nep1 is not required for acp-modification but suggested a function in Ψ1191 methylation. ESI MS analysis of acp-modified Ψ-nucleosides in a Δnep1-mutant showed that Nep1 catalyzes the Ψ1191 methylation in vivo. Remarkably, the restored growth of a nep1-1ts mutant upon addition of S-adenosylmethionine was even observed after preventing U1191 methylation in a Δsnr35 mutant. This strongly suggests a dual Nep1 function, as Ψ1191-methyltransferase and ribosome assembly factor. Interestingly, the Nep1 methyltransferase activity is not affected upon introduction of the BCS mutation. Instead, the mutated protein shows enhanced dimerization propensity and increased affinity for its RNA-target in vitro. Furthermore, the BCS mutation prevents nucleolar accumulation of Nep1, which could be the reason for reduced growth in yeast and the Bowen-Conradi syndrome.
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Affiliation(s)
- Britta Meyer
- Cluster of Excellence Frankfurt: Macromolecular Complexes, Max-von-Laue Str. 9, D-60438 Frankfurt/M., Germany
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9
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Steigele S, Huber W, Stocsits C, Stadler PF, Nieselt K. Comparative analysis of structured RNAs in S. cerevisiae indicates a multitude of different functions. BMC Biol 2007; 5:25. [PMID: 17577407 PMCID: PMC1914338 DOI: 10.1186/1741-7007-5-25] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Accepted: 06/18/2007] [Indexed: 01/06/2023] Open
Abstract
Background Non-coding RNAs (ncRNAs) are an emerging focus for both computational analysis and experimental research, resulting in a growing number of novel, non-protein coding transcripts with often unknown functions. Whole genome screens in higher eukaryotes, for example, provided evidence for a surprisingly large number of ncRNAs. To supplement these searches, we performed a computational analysis of seven yeast species and searched for new ncRNAs and RNA motifs. Results A comparative analysis of the genomes of seven yeast species yielded roughly 2800 genomic loci that showed the hallmarks of evolutionary conserved RNA secondary structures. A total of 74% of these regions overlapped with annotated non-coding or coding genes in yeast. Coding sequences that carry predicted structured RNA elements belong to a limited number of groups with common functions, suggesting that these RNA elements are involved in post-transcriptional regulation and/or cellular localization. About 700 conserved RNA structures were found outside annotated coding sequences and known ncRNA genes. Many of these predicted elements overlapped with UTR regions of particular classes of protein coding genes. In addition, a number of RNA elements overlapped with previously characterized antisense transcripts. Transcription of about 120 predicted elements located in promoter regions and other, previously un-annotated, intergenic regions was supported by tiling array experiments, ESTs, or SAGE data. Conclusion Our computational predictions strongly suggest that yeasts harbor a substantial pool of several hundred novel ncRNAs. In addition, we describe a large number of RNA structures in coding sequences and also within antisense transcripts that were previously characterized using tiling arrays.
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Affiliation(s)
- Stephan Steigele
- Wilhelm-Schickard-Institut für Informatik, ZBIT-Center for Bioinformatics Tübingen, University of Tübingen, Sand-14, D-72076 Tübingen, Germany
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics (IZBI), University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany
| | - Wolfgang Huber
- EMBL Outstation Hinxton, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Claudia Stocsits
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics (IZBI), University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics (IZBI), University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany
- Department of Theoretical Chemistry University of Vienna, Währingerstraße 17, A-1090 Wien, Austria
- Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM 87501, USA
| | - Kay Nieselt
- Wilhelm-Schickard-Institut für Informatik, ZBIT-Center for Bioinformatics Tübingen, University of Tübingen, Sand-14, D-72076 Tübingen, Germany
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10
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11
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Khanna M, Wu H, Johansson C, Caizergues-Ferrer M, Feigon J. Structural study of the H/ACA snoRNP components Nop10p and the 3' hairpin of U65 snoRNA. RNA (NEW YORK, N.Y.) 2006; 12:40-52. [PMID: 16373493 PMCID: PMC1370884 DOI: 10.1261/rna.2221606] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The H/ACA small nucleolar ribonucleoprotein (snoRNP) complexes guide the modification of uridine to pseudouridine at conserved sites in rRNA. The H/ACA snoRNPs each comprise a target-site-specific snoRNA and four core proteins, Nop10p, Nhp2p, Gar1p, and the pseudouridine synthase, Cbf5p, in yeast. The secondary structure of the H/ACA snoRNAs includes two hairpins that each contain a large internal loop (the pseudouridylation pocket), one or both of which are partially complementary to the target RNA(s). We have determined the solution structure of an RNA hairpin derived from the human U65 box H/ACA snoRNA including the pseudouridylation pocket and adjacent stems, providing the first three-dimensional structural information on these H/ACA snoRNAs. We have also determined the structure of Nop10p and investigated its interaction with RNA using NMR spectroscopy. Nop10p contains a structurally well-defined N-terminal region composed of a beta-hairpin, and the rest of the protein lacks a globular structure. Chemical shift mapping of the interaction of RNA constructs of U65 box H/ACA 3' hairpin with Nop10p shows that the beta-hairpin binds weakly but specifically to RNA. The unstructured region of Nop10p likely interacts with Cbf5p.
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Affiliation(s)
- May Khanna
- Department of Chemistry and Biochemistry, 607 Charles Young Drive East, P.O. Box 951569, University of California, Los Angeles, CA 90095-1569, USA
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12
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Meier UT. The many facets of H/ACA ribonucleoproteins. Chromosoma 2005; 114:1-14. [PMID: 15770508 PMCID: PMC4313906 DOI: 10.1007/s00412-005-0333-9] [Citation(s) in RCA: 215] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2004] [Revised: 01/31/2005] [Accepted: 02/01/2005] [Indexed: 10/25/2022]
Abstract
The H/ACA ribonucleoproteins (RNPs) are known as one of the two major classes of small nucleolar RNPs. They predominantly guide the site-directed pseudouridylation of target RNAs, such as ribosomal and spliceosomal small nuclear RNAs. In addition, they process ribosomal RNA and stabilize vertebrate telomerase RNA. Taken together, the function of H/ACA RNPs is essential for ribosome biogenesis, pre-mRNA splicing, and telomere maintenance. Every cell contains 100-200 different species of H/ACA RNPs, each consisting of the same four core proteins and one function-specifying H/ACA RNA. Most of these RNPs reside in nucleoli and Cajal bodies and mediate the isomerization of specific uridines to pseudouridines. Catalysis of the reaction is mediated by the putative pseudouridylase NAP57 (dyskerin, Cbf5p). Unexpectedly, mutations in this housekeeping enzyme are the major determinants of the inherited bone marrow failure syndrome dyskeratosis congenita. This review details the many diverse functions of H/ACA RNPs, some yet to be uncovered, with an emphasis on the role of the RNP proteins. The multiple functions of H/ACA RNPs appear to be reflected in the complex phenotype of dyskeratosis congenita.
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Affiliation(s)
- U Thomas Meier
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
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13
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Lapeyre B. Conserved ribosomal RNA modification and their putative roles in ribosome biogenesis and translation. ACTA ACUST UNITED AC 2004. [DOI: 10.1007/b105433] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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14
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Abstract
It has been known for nearly half a century that coding and non-coding RNAs (mRNA, and tRNAs and rRNAs respectively) play critical roles in the process of information transfer from DNA to protein. What is both surprising and exciting, are the discoveries in the last decade that cells, particularly eukaryotic cells, contain a plethora of non-coding RNAs and that these RNAs can either possess catalytic activity or can function as integral components of dynamic ribonucleoprotein machines. These machines appear to mediate diverse, complex and essential processes such as intron excision, RNA modification and editing, protein targeting, DNA packaging, etc. Archaea have been shown to possess RNP complexes; some of these are authentic homologues of the eukaryotic complexes that function as machines in the processing, modification and assembly of rRNA into ribosomal subunits. Deciphering how these RNA-containing machines function will require a dissection and analysis of the component parts, an understanding of how the parts fit together and an ability to reassemble the parts into complexes that can function in vitro. This article summarizes our current knowledge about small-non-coding RNAs in Archaea, their roles in ribosome biogenesis and their relationships to the complexes that have been identified in eukaryotic cells.
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Affiliation(s)
- Arina D Omer
- Department of Biochemistry and Molecular Biology, University of British Columbia, 2146 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
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15
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King TH, Liu B, McCully RR, Fournier MJ. Ribosome structure and activity are altered in cells lacking snoRNPs that form pseudouridines in the peptidyl transferase center. Mol Cell 2003; 11:425-35. [PMID: 12620230 DOI: 10.1016/s1097-2765(03)00040-6] [Citation(s) in RCA: 207] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
One of the oldest questions in RNA science is the role of nucleotide modification. Here, the importance of pseudouridine formation (Psi) in the peptidyl transferase center of rRNA was examined by depleting yeast cells of 1-5 snoRNAs that guide a total of six Psi modifications. Translation was impaired substantially with loss of a conserved Psi in the A site of tRNA binding. Depletion of other Psis had subtle or no apparent effect on activity; however, synergistic effects were observed in some combinations. Pseudouridines are proposed to enhance ribosome activity by altering rRNA folding and interactions, with some Psis having greater effects than others. The possibility that modifying snoRNPs might affect ribosome structure in other ways is also discussed.
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MESH Headings
- Base Sequence
- Cell Division
- Models, Molecular
- Molecular Sequence Data
- Nucleic Acid Conformation
- Peptidyl Transferases/chemistry
- Peptidyl Transferases/metabolism
- Protein Biosynthesis
- Protein Structure, Secondary
- Pseudouridine/metabolism
- RNA Processing, Post-Transcriptional
- RNA, Fungal/chemistry
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Small Nucleolar/chemistry
- RNA, Small Nucleolar/genetics
- RNA, Small Nucleolar/metabolism
- Ribonucleoproteins, Small Nucleolar/metabolism
- Ribosomes/chemistry
- Ribosomes/metabolism
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Saccharomyces cerevisiae Proteins/metabolism
- RNA, Small Untranslated
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Affiliation(s)
- Thomas H King
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
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16
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Massenet S, Ansmant I, Motorin Y, Branlant C. The first determination of pseudouridine residues in 23S ribosomal RNA from hyperthermophilic Archaea Sulfolobus acidocaldarius. FEBS Lett 1999; 462:94-100. [PMID: 10580099 DOI: 10.1016/s0014-5793(99)01524-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We describe the first identification of pseudouridine (Psi) residues in ribosomal RNA (23S rRNA) of an hyperthermophilic Archaea Sulfolobus acidocaldarius. In contrast to Eucarya rRNA, only six Psi residues were detected, which is rather close to the situation in Bacteria. However, three modified positions (Psi(2479), Psi(2535) and Psi(2550)) are unique for S. acidocaldarius. Two Psi residues at positions 2060 and 2594 are universally conserved, while one other Psi (position 2066) is also common to Eucarya. Taken together the results argue against the conservation of Psi-synthases between Archaea and Bacteria and provide a basis for the search of snoRNA-like guides for Psi formation in Archaea.
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Affiliation(s)
- S Massenet
- Laboratoire de Maturation des ARN et Enzymologie Moléculaire, UMR 7567 CNRS-UHP Nancy I, Faculté des Sciences, P.O. Box 239, 54506, Vandoeuvre-les-Nancy, France
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17
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Samarsky DA, Ferbeyre G, Bertrand E, Singer RH, Cedergren R, Fournier MJ. A small nucleolar RNA:ribozyme hybrid cleaves a nucleolar RNA target in vivo with near-perfect efficiency. Proc Natl Acad Sci U S A 1999; 96:6609-14. [PMID: 10359759 PMCID: PMC21962 DOI: 10.1073/pnas.96.12.6609] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A hammerhead ribozyme has been localized to the yeast nucleolus by using the U3 small nucleolar RNA as a carrier. The hybrid small nucleolar RNA:ribozyme, designated a "snorbozyme," is metabolically stable and cleaves a target U3 RNA with nearly 100% efficiency in vivo. This is the most efficient in vivo cleavage reported for a trans-acting ribozyme. A key advantage of the model substrate featured is that a stable, trimmed cleavage product accumulates. This property allows accurate kinetic measurements of authentic cleavage in vivo. The system offers new avenues for developing effective ribozymes for research and therapeutic applications.
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Affiliation(s)
- D A Samarsky
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
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18
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Chanfreau G, Legrain P, Jacquier A. Yeast RNase III as a key processing enzyme in small nucleolar RNAs metabolism. J Mol Biol 1998; 284:975-88. [PMID: 9837720 DOI: 10.1006/jmbi.1998.2237] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The variety of biogenesis pathways for small nucleolar RNAs (snoRNAs) reflects the diversity of their genomic organization. We have searched for yeast snoRNAs which are affected by the depletion of the yeast ortholog of bacterial RNase III, Rnt1. In a yeast strain inactivated for RNT1, almost half of the snoRNAs tested are depleted with significant accumulation of monocistronic or polycistronic precursors. snoRNAs from both major families of snoRNAs (C/D and H/ACA) are affected by RNT1 disruption. In vitro, recombinant Rnt1 specifically cleaves pre-snoRNA precursors in the absence of other factors, generating intermediates which require the action of other enzymes for processing to the mature snoRNA. Most Rnt1 cleavage sites fall within potentially double-stranded regions closed by tetraloops with a novel consensus sequence AGNN. These results demonstrate that biogenesis of a large number of snoRNAs from the two major families of snoRNAs requires a common RNA endonuclease and a putative conserved structural motif.
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Affiliation(s)
- G Chanfreau
- Laboratoire du Métabolisme des ARN, URA1300 CNRS, Institut Pasteur, Département des Biotechnologies, 25 rue du Dr Roux, Paris Cedex 15, F-75724, France.
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19
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Samarsky DA, Fournier MJ, Singer RH, Bertrand E. The snoRNA box C/D motif directs nucleolar targeting and also couples snoRNA synthesis and localization. EMBO J 1998; 17:3747-57. [PMID: 9649444 PMCID: PMC1170710 DOI: 10.1093/emboj/17.13.3747] [Citation(s) in RCA: 153] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Most small nucleolar RNAs (snoRNAs) fall into two families, known as the box C/D and box H/ACA snoRNAs. The various box elements are essential for snoRNA production and for snoRNA-directed modification of rRNA nucleotides. In the case of the box C/D snoRNAs, boxes C and D and an adjoining stem form a vital structure, known as the box C/D motif. Here, we examined expression of natural and artificial box C/D snoRNAs in yeast and mammalian cells, to assess the role of the box C/D motif in snoRNA localization. The results demonstrate that the motif is necessary and sufficient for nucleolar targeting, both in yeast and mammals. Moreover, in mammalian cells, RNA is targeted to coiled bodies as well. Thus, the box C/D motif is the first intranuclear RNA trafficking signal identified for an RNA family. Remarkably, it also couples snoRNA localization with synthesis and, most likely, function. The distribution of snoRNA precursors in mammalian cells suggests that this coupling is provided by a specific protein(s) which binds the box C/D motif during or rapidly after snoRNA transcription. The conserved nature of the box C/D motif indicates that its role in coupling production and localization of snoRNAs is of ancient evolutionary origin.
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Affiliation(s)
- D A Samarsky
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
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20
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Samarsky DA, Fournier MJ. Functional mapping of the U3 small nucleolar RNA from the yeast Saccharomyces cerevisiae. Mol Cell Biol 1998; 18:3431-44. [PMID: 9584183 PMCID: PMC108924 DOI: 10.1128/mcb.18.6.3431] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/1997] [Accepted: 03/05/1998] [Indexed: 02/07/2023] Open
Abstract
The U3 small nucleolar RNA participates in early events of eukaryotic pre-rRNA cleavage and is essential for formation of 18S rRNA. Using an in vivo system, we have developed a functional map of the U3 small nucleolar RNA from Saccharomyces cerevisiae. The test strain features a galactose-dependent U3 gene in the chromosome and a plasmid-encoded allele with a unique hybridization tag. Effects of mutations on U3 production were analyzed by evaluating RNA levels in cells grown on galactose medium, and effects on U3 function were assessed by growing cells on glucose medium. The major findings are as follows: (i) boxes C' and D and flanking helices are critical for U3 accumulation; (ii) boxes B and C are not essential for U3 production but are important for function, most likely due to binding of a trans-acting factor(s); (iii) the 5' portion of U3 is required for function but not stability; and, (iv) strikingly, the nonconserved hairpins 2, 3, and 4, which account for 50% of the molecule, are not required for accumulation or function.
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Affiliation(s)
- D A Samarsky
- Department of Biochemistry and Molecular Biology, Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, Massachusetts 01003, USA
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21
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Maden BE, Hughes JM. Eukaryotic ribosomal RNA: the recent excitement in the nucleotide modification problem. Chromosoma 1997; 105:391-400. [PMID: 9211966 DOI: 10.1007/bf02510475] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Eukaryotic ribosomal RNA (rRNA) contains numerous modified nucleotides: about 115 methyl groups and some 95 pseudouridines in vertebrates; about 65 methyl groups and some 45 pseudouridines in Saccharomyces cerevisiae. All but about ten of the methyl groups are ribose methylations. The remaining ten are on heterocyclic bases. The ribose methylations occur very rapidly upon the primary rRNA transcript in the nucleolus, probably on nascent chains, and they appear to play an important role in ribosome maturation, at least in vertebrates. All of the methyl groups occur in the conserved core of rRNA. However, there is no consensus feature of sequence or secondary structure for the methylation sites; thus the nature of the signal(s) for site-specific methylations had until recently remained a mystery. The situation changed dramatically with the discovery that many of the ribose methylation sites are in regions that are precisely complementary to small nucleolar RNA (snoRNA) species. Experimental evidence indicates that structural motifs within the snoRNA species do indeed pinpoint the precise nucleotides to be methylated by the putative 2'-O-methyl transferase(s). Regarding base methylations, the gene DIM1, responsible for modification of the conserved dimethyladenosines near the 3' end of 18S rRNA, has been shown to be essential for viability in S. cerevisiae and is suggested to play a role in the nucleocytoplasmic transport of the small ribosomal subunit. Recently nearly all of the pseudouridines have also been mapped in the rRNA of several eukaryotic species. As is the case for ribose methylations, most pseudouridine modifications occur rapidly upon precursor rRNA, within core sequences, and in a variety of local primary and secondary structure environments. In contrast to ribose methylation, no potentially unifying process has yet been identified for the enzymic recognition of the many pseudouridine modification sites. However, the new data afford the basis for a search for any potential involvement of snoRNAs in the recognition process.
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Affiliation(s)
- B E Maden
- School of Biological Sciences, Life Sciences Building, University of Liverpool, Liverpool L69 7ZB, UK
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22
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Ganot P, Bortolin ML, Kiss T. Site-specific pseudouridine formation in preribosomal RNA is guided by small nucleolar RNAs. Cell 1997; 89:799-809. [PMID: 9182768 DOI: 10.1016/s0092-8674(00)80263-9] [Citation(s) in RCA: 469] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
During the nucleolar maturation of eukaryotic ribosomal RNAs, many selected uridines are converted into pseudouridine by a thus far undefined mechanism. The nucleolus contains a large number of small RNAs (snoRNAs) that share two conserved sequence elements, box H and ACA. In this study, we demonstrate that site-specific pseudouridylation of rRNAs relies on short ribosomal signal sequences that are complementary to sequences in box H/ACA snoRNAs. Genetic depletion and reconstitution studies on yeast snR5 and snR36 snoRNAs demonstrate that box H/ACA snoRNAs function as guide RNAs in rRNA pseudouridylation. These results define a novel function for snoRNAs and further reinforce the idea that base pairing is the most common way to obtain specific substrate-"enzyme" interactions during rRNA maturation.
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Affiliation(s)
- P Ganot
- Laboratoire de Biologie Moléculaire du CNRS, Université Paul Sabatier, Toulouse, France
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23
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Ni J, Tien AL, Fournier MJ. Small nucleolar RNAs direct site-specific synthesis of pseudouridine in ribosomal RNA. Cell 1997; 89:565-73. [PMID: 9160748 DOI: 10.1016/s0092-8674(00)80238-x] [Citation(s) in RCA: 386] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Ten ACA yeast small nucleolar RNAs (snoRNAs) were shown to be required for site-specific synthesis of pseudouridine psi in ribosomal RNA. A common secondary folding motif for the snoRNAs and rRNA target segments predicts that site selection involves: (1) base pairing of the snoRNA with complementary rRNA elements flanking the site of modification, and (2) identification of a uridine located at a near-constant distance from the snoRNA ACA box. The model is supported by mutations showing that: (1) reducing the complementarity between the snoRNA and rRNA disrupts psi formation, and (2) altering the distance between the ACA box and target uridine causes an adjacent uridine to be modified. This discovery implies that most snoRNAs function in targeting nucleotide modification in rRNA: ribose methylation for the box C/D snoRNAs and psi formation for the ACA snoRNAs.
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MESH Headings
- Animals
- Base Sequence
- Cell Nucleolus/metabolism
- Chick Embryo
- Models, Biological
- Molecular Sequence Data
- Molecular Structure
- Mutation
- Nucleic Acid Conformation
- Pseudouridine/biosynthesis
- RNA, Fungal/chemistry
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- RNA, Small Nuclear/chemistry
- RNA, Small Nuclear/genetics
- RNA, Small Nuclear/metabolism
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
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Affiliation(s)
- J Ni
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst 01003, USA
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24
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Ganot P, Caizergues-Ferrer M, Kiss T. The family of box ACA small nucleolar RNAs is defined by an evolutionarily conserved secondary structure and ubiquitous sequence elements essential for RNA accumulation. Genes Dev 1997; 11:941-56. [PMID: 9106664 DOI: 10.1101/gad.11.7.941] [Citation(s) in RCA: 245] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Eukaryotic cells contain a large number of small nucleolar RNAs (snoRNAs). A major family of snoRNAs features a consensus ACA motif positioned 3 nucleotides from the 3' end of the RNA. In this study we have characterized nine novel human ACA snoRNAs (U64-U72). Structural probing of U64 RNA followed by systematic computer modeling of all known box ACA snoRNAs revealed that this class of snoRNAs is defined by a phylogenetically conserved secondary structure. The ACA snoRNAs fold into two hairpin structures connected by a single-stranded hinge region and followed by a short 3' tail. The hinge region carries an evolutionarily conserved sequence motif, called box H (consensus, AnAnnA). The H box, probably in concert with the flanking helix structures and the ACA box characterized previously, plays an essential role in the accumulation of human U64 intronic snoRNA. The correct processing of a yeast ACA snoRNA, snR36, in mammalian cells demonstrated that the cis- and trans-acting elements required for processing and accumulation of ACA snoRNAs are evolutionarily conserved. The notion that ACA snoRNAs share a common secondary structure and conserved box elements that likely function as binding sites for common proteins (e.g., GAR1) suggests that these RNAs possess closely related nucleolar functions.
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Affiliation(s)
- P Ganot
- Laboratoire de Biologie Moléculaire Eucaryote du Centre National de laRecherche (CNRS), Université Paul Sabatier, Toulouse, France
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25
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Balakin AG, Smith L, Fournier MJ. The RNA world of the nucleolus: two major families of small RNAs defined by different box elements with related functions. Cell 1996; 86:823-34. [PMID: 8797828 DOI: 10.1016/s0092-8674(00)80156-7] [Citation(s) in RCA: 338] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have discovered that all known yeast and vertebrate small nucleolar RNAs (snoRNAs), except for the MRP/7-2 RNA, fall into two major classes. One class is defined by conserved boxes C and D and the other by a novel element: a consensus ACA triplet positioned 3 nt before the 3' end of the RNA. A role for the ACA box is snoRNA stability has been established by mutational analysis of a yeast ACA snoRNA (snR 11). Full function of the box depends on the integrity of an adjacent upstream stem. All members of the yeast ACA family are associated with the GAR1 protein. Binding of this or another common small nucleolar ribonucleoprotein particle protein is predicted to be a critical entry point to snoRNA posttranscriptional life, including precise formation of the snoRNA 3' end.
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Affiliation(s)
- A G Balakin
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst 01003, USA
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26
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Samarsky DA, Schneider GS, Fournier MJ. An essential domain in Saccharomyces cerevisiae U14 snoRNA is absent in vertebrates, but conserved in other yeasts. Nucleic Acids Res 1996; 24:2059-66. [PMID: 8668536 PMCID: PMC145897 DOI: 10.1093/nar/24.11.2059] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
U14 is a small nucleolar RNA (snoRNA) required for early cleavages of eukaryotic precursor rRNA. The U14 RNA from Saccharomyces cerevisiae is distinguished from its vertebrate homologues by the presence of a stem-loop domain that is essential for function. This element, known as the Y-domain, is located in the U14 sequence between two universal sequences that base pair with 18S rRNA. Sequence data obtained for the U14 homologues from four additional phylogenetically distinct yeasts showed the Y-domain is not unique to S.cerevisiae. Comparison of the five Y-domain sequences revealed a common stem-loop structure with a conserved loop sequence that includes eight invariant nucleotides. Conservation of these features suggests that the Y-domain is a recognition signal for an essential interaction. Several plant U14 RNAs were found to contain similar structures, though with an unrelated consensus sequence in the loop portion. The U14 gene from the most distantly related yeast, Schizosaccharomyces pombe, was found to be active in S.cerevisiae, showing that Y-domain function is conserved and that U14 function can be provided by variants in which the essential elements are embedded in dissimilar flanking sequences. This last result suggests that U14 function may be determined solely by the essential elements.
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Affiliation(s)
- D A Samarsky
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
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27
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Abstract
Post-transcriptional processing of precursor-ribosomal RNA comprises a complex pathway of endonucleolytic cleavages, exonucleolytic digestion and covalent modifications. The general order of the various processing steps is well conserved in eukaryotic cells, but the underlying mechanisms are largely unknown. Recent analysis of pre-rRNA processing, mainly in the yeast Saccharomyces cerevisiae, has significantly improved our understanding of this important cellular activity. Here we will review the data that have led to our current picture of yeast pre-rRNA processing.
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Affiliation(s)
- J Venema
- European Molecular Biology Laboratory (EMBL), Gene Expression Programme, Heidelberg, Germany
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