51
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Jespersen N, Monrroy L, Barandun J. Impact of Genome Reduction in Microsporidia. EXPERIENTIA SUPPLEMENTUM (2012) 2022; 114:1-42. [PMID: 35543997 DOI: 10.1007/978-3-030-93306-7_1] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Microsporidia represent an evolutionary outlier in the tree of life and occupy the extreme edge of the eukaryotic domain with some of their biological features. Many of these unicellular fungi-like organisms have reduced their genomic content to potentially the lowest limit. With some of the most compacted eukaryotic genomes, microsporidia are excellent model organisms to study reductive evolution and its functional consequences. While the growing number of sequenced microsporidian genomes have elucidated genome composition and organization, a recent increase in complementary post-genomic studies has started to shed light on the impacts of genome reduction in these unique pathogens. This chapter will discuss the biological framework enabling genome minimization and will use one of the most ancient and essential macromolecular complexes, the ribosome, to illustrate the effects of extreme genome reduction on a structural, molecular, and cellular level. We outline how reductive evolution in microsporidia has shaped DNA organization, the composition and function of the ribosome, and the complexity of the ribosome biogenesis process. Studying compacted mechanisms, processes, or macromolecular machines in microsporidia illuminates their unique lifestyle and provides valuable insights for comparative eukaryotic structural biology.
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Affiliation(s)
- Nathan Jespersen
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Science for Life Laboratory, Umeå University, Umeå, Sweden.
| | - Leonardo Monrroy
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Science for Life Laboratory, Umeå University, Umeå, Sweden
| | - Jonas Barandun
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Science for Life Laboratory, Umeå University, Umeå, Sweden.
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52
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Oborská-Oplová M, Fischer U, Altvater M, Panse VG. Eukaryotic Ribosome assembly and Nucleocytoplasmic Transport. Methods Mol Biol 2022; 2533:99-126. [PMID: 35796985 PMCID: PMC9761919 DOI: 10.1007/978-1-0716-2501-9_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The process of eukaryotic ribosome assembly stretches across the nucleolus, the nucleoplasm and the cytoplasm, and therefore relies on efficient nucleocytoplasmic transport. In yeast, the import machinery delivers ~140,000 ribosomal proteins every minute to the nucleus for ribosome assembly. At the same time, the export machinery facilitates translocation of ~2000 pre-ribosomal particles every minute through ~200 nuclear pore complexes (NPC) into the cytoplasm. Eukaryotic ribosome assembly also requires >200 conserved assembly factors, which transiently associate with pre-ribosomal particles. Their site(s) of action on maturing pre-ribosomes are beginning to be elucidated. In this chapter, we outline protocols that enable rapid biochemical isolation of pre-ribosomal particles for single particle cryo-electron microscopy (cryo-EM) and in vitro reconstitution of nuclear transport processes. We discuss cell-biological and genetic approaches to investigate how the ribosome assembly and the nucleocytoplasmic transport machineries collaborate to produce functional ribosomes.
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Affiliation(s)
- Michaela Oborská-Oplová
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Ute Fischer
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | | | - Vikram Govind Panse
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland.
- Faculty of Science, University of Zurich, Zurich, Switzerland.
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53
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Pöll G, Pilsl M, Griesenbeck J, Tschochner H, Milkereit P. Analysis of subunit folding contribution of three yeast large ribosomal subunit proteins required for stabilisation and processing of intermediate nuclear rRNA precursors. PLoS One 2021; 16:e0252497. [PMID: 34813592 PMCID: PMC8610266 DOI: 10.1371/journal.pone.0252497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 10/17/2021] [Indexed: 11/19/2022] Open
Abstract
In yeast and human cells many of the ribosomal proteins (r-proteins) are required for the stabilisation and productive processing of rRNA precursors. Functional coupling of r-protein assembly with the stabilisation and maturation of subunit precursors potentially promotes the production of ribosomes with defined composition. To further decipher mechanisms of such an intrinsic quality control pathway we analysed here the contribution of three yeast large ribosomal subunit r-proteins rpL2 (uL2), rpL25 (uL23) and rpL34 (eL34) for intermediate nuclear subunit folding steps. Structure models obtained from single particle cryo-electron microscopy analyses provided evidence for specific and hierarchic effects on the stable positioning and remodelling of large ribosomal subunit domains. Based on these structural and previous biochemical data we discuss possible mechanisms of r-protein dependent hierarchic domain arrangement and the resulting impact on the stability of misassembled subunits.
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Affiliation(s)
- Gisela Pöll
- Chair of Biochemistry III, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Michael Pilsl
- Structural Biochemistry Unit, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Joachim Griesenbeck
- Chair of Biochemistry III, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
- * E-mail: (JG); (HT); (PM)
| | - Herbert Tschochner
- Chair of Biochemistry III, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
- * E-mail: (JG); (HT); (PM)
| | - Philipp Milkereit
- Chair of Biochemistry III, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
- * E-mail: (JG); (HT); (PM)
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54
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Aquino GRR, Hackert P, Krogh N, Pan KT, Jaafar M, Henras AK, Nielsen H, Urlaub H, Bohnsack KE, Bohnsack MT. The RNA helicase Dbp7 promotes domain V/VI compaction and stabilization of inter-domain interactions during early 60S assembly. Nat Commun 2021; 12:6152. [PMID: 34686661 PMCID: PMC8536713 DOI: 10.1038/s41467-021-26208-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 09/22/2021] [Indexed: 02/07/2023] Open
Abstract
Early pre-60S ribosomal particles are poorly characterized, highly dynamic complexes that undergo extensive rRNA folding and compaction concomitant with assembly of ribosomal proteins and exchange of assembly factors. Pre-60S particles contain numerous RNA helicases, which are likely regulators of accurate and efficient formation of appropriate rRNA structures. Here we reveal binding of the RNA helicase Dbp7 to domain V/VI of early pre-60S particles in yeast and show that in the absence of this protein, dissociation of the Npa1 scaffolding complex, release of the snR190 folding chaperone, recruitment of the A3 cluster factors and binding of the ribosomal protein uL3 are impaired. uL3 is critical for formation of the peptidyltransferase center (PTC) and is responsible for stabilizing interactions between the 5′ and 3′ ends of the 25S, an essential pre-requisite for subsequent pre-60S maturation events. Highlighting the importance of pre-ribosome remodeling by Dbp7, our data suggest that in the absence of Dbp7 or its catalytic activity, early pre-ribosomal particles are targeted for degradation. Early steps of large 60S ribosomal subunit biogenesis are not well understood. Here, the authors combine biochemical experiments with protein-RNA crosslinking and mass spectrometry to show that the RNA helicase Dbp7 is key player during early 60S ribosomal assembly. Dbp7 regulates a series of events driving compaction of domain V/VI in early pre60S ribosomal particles.
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Affiliation(s)
- Gerald Ryan R Aquino
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Philipp Hackert
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Nicolai Krogh
- Department of Cellular and Molecular Medicine, University of Copenhagen, 2200N, Copenhagen, Denmark
| | - Kuan-Ting Pan
- Max Planck Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry, 37077, Göttingen, Germany.,Hematology/Oncology, Department of Medicine II, Johann Wolfgang Goethe University, 60590, Frankfurt am Main, Germany.,Frankfurt Cancer Institute, Goethe University, 60596, Frankfurt am Main, Germany
| | - Mariam Jaafar
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062, Toulouse, France
| | - Anthony K Henras
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062, Toulouse, France
| | - Henrik Nielsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, 2200N, Copenhagen, Denmark.,Genomics Group, Faculty of Biosciences and Aquaculture, Nord University, 8049, Bodø, Norway
| | - Henning Urlaub
- Max Planck Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry, 37077, Göttingen, Germany.,Institute for Clinical Chemistry, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany. .,Göttingen Centre for Molecular Biosciences, Georg-August-University, Justus-von-Liebig Weg 11, 37077, Göttingen, Germany.
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55
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Birikmen M, Bohnsack KE, Tran V, Somayaji S, Bohnsack MT, Ebersberger I. Tracing Eukaryotic Ribosome Biogenesis Factors Into the Archaeal Domain Sheds Light on the Evolution of Functional Complexity. Front Microbiol 2021; 12:739000. [PMID: 34603269 PMCID: PMC8481954 DOI: 10.3389/fmicb.2021.739000] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 08/17/2021] [Indexed: 01/23/2023] Open
Abstract
Ribosome assembly is an essential and carefully choreographed cellular process. In eukaryotes, several 100 proteins, distributed across the nucleolus, nucleus, and cytoplasm, co-ordinate the step-wise assembly of four ribosomal RNAs (rRNAs) and approximately 80 ribosomal proteins (RPs) into the mature ribosomal subunits. Due to the inherent complexity of the assembly process, functional studies identifying ribosome biogenesis factors and, more importantly, their precise functions and interplay are confined to a few and very well-established model organisms. Although best characterized in yeast (Saccharomyces cerevisiae), emerging links to disease and the discovery of additional layers of regulation have recently encouraged deeper analysis of the pathway in human cells. In archaea, ribosome biogenesis is less well-understood. However, their simpler sub-cellular structure should allow a less elaborated assembly procedure, potentially providing insights into the functional essentials of ribosome biogenesis that evolved long before the diversification of archaea and eukaryotes. Here, we use a comprehensive phylogenetic profiling setup, integrating targeted ortholog searches with automated scoring of protein domain architecture similarities and an assessment of when search sensitivity becomes limiting, to trace 301 curated eukaryotic ribosome biogenesis factors across 982 taxa spanning the tree of life and including 727 archaea. We show that both factor loss and lineage-specific modifications of factor function modulate ribosome biogenesis, and we highlight that limited sensitivity of the ortholog search can confound evolutionary conclusions. Projecting into the archaeal domain, we find that only few factors are consistently present across the analyzed taxa, and lineage-specific loss is common. While members of the Asgard group are not special with respect to their inventory of ribosome biogenesis factors (RBFs), they unite the highest number of orthologs to eukaryotic RBFs in one taxon. Using large ribosomal subunit maturation as an example, we demonstrate that archaea pursue a simplified version of the corresponding steps in eukaryotes. Much of the complexity of this process evolved on the eukaryotic lineage by the duplication of ribosomal proteins and their subsequent functional diversification into ribosome biogenesis factors. This highlights that studying ribosome biogenesis in archaea provides fundamental information also for understanding the process in eukaryotes.
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Affiliation(s)
- Mehmet Birikmen
- Applied Bioinformatics Group, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Vinh Tran
- Applied Bioinformatics Group, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Sharvari Somayaji
- Applied Bioinformatics Group, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.,Göttingen Center for Molecular Biosciences, Georg-August University, Göttingen, Germany
| | - Ingo Ebersberger
- Applied Bioinformatics Group, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt, Germany.,Senckenberg Biodiversity and Climate Research Center (S-BIK-F), Frankfurt, Germany.,LOEWE Center for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt, Germany
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56
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The nucleolar DExD/H protein Hel66 is involved in ribosome biogenesis in Trypanosoma brucei. Sci Rep 2021; 11:18325. [PMID: 34526538 PMCID: PMC8443567 DOI: 10.1038/s41598-021-97020-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/30/2021] [Indexed: 01/23/2023] Open
Abstract
The biosynthesis of ribosomes is a complex cellular process involving ribosomal RNA, ribosomal proteins and several further trans-acting factors. DExD/H box proteins constitute the largest family of trans-acting protein factors involved in this process. Several members of this protein family have been directly implicated in ribosome biogenesis in yeast. In trypanosomes, ribosome biogenesis differs in several features from the process described in yeast. Here, we have identified the DExD/H box helicase Hel66 as being involved in ribosome biogenesis. The protein is unique to Kinetoplastida, localises to the nucleolus and its depletion via RNAi caused a severe growth defect. Loss of the protein resulted in a decrease of global translation and accumulation of rRNA processing intermediates for both the small and large ribosomal subunits. Only a few factors involved in trypanosome rRNA biogenesis have been described so far and our findings contribute to gaining a more comprehensive picture of this essential process.
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57
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Erdmann PS, Hou Z, Klumpe S, Khavnekar S, Beck F, Wilfling F, Plitzko JM, Baumeister W. In situ cryo-electron tomography reveals gradient organization of ribosome biogenesis in intact nucleoli. Nat Commun 2021; 12:5364. [PMID: 34508074 PMCID: PMC8433212 DOI: 10.1038/s41467-021-25413-w] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 08/09/2021] [Indexed: 02/08/2023] Open
Abstract
Ribosomes comprise a large (LSU) and a small subunit (SSU) which are synthesized independently in the nucleolus before being exported into the cytoplasm, where they assemble into functional ribosomes. Individual maturation steps have been analyzed in detail using biochemical methods, light microscopy and conventional electron microscopy (EM). In recent years, single particle analysis (SPA) has yielded molecular resolution structures of several pre-ribosomal intermediates. It falls short, however, of revealing the spatiotemporal sequence of ribosome biogenesis in the cellular context. Here, we present our study on native nucleoli in Chlamydomonas reinhardtii, in which we follow the formation of LSU and SSU precursors by in situ cryo-electron tomography (cryo-ET) and subtomogram averaging (STA). By combining both positional and molecular data, we reveal gradients of ribosome maturation within the granular component (GC), offering a new perspective on how the liquid-liquid-phase separation of the nucleolus supports ribosome biogenesis.
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Affiliation(s)
- Philipp S Erdmann
- Max Planck Institute of Biochemistry, Martinsried, Germany.
- Fondazione Human Technopole, Milano, Italy.
| | - Zhen Hou
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Sven Klumpe
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | | | - Florian Beck
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Florian Wilfling
- Max Planck Institute of Biochemistry, Martinsried, Germany
- Max Planck Institute of Biophysics, Frankfurt, Germany
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58
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Puf6 primes 60S pre-ribosome nuclear export at low temperature. Nat Commun 2021; 12:4696. [PMID: 34349113 PMCID: PMC8338941 DOI: 10.1038/s41467-021-24964-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 07/16/2021] [Indexed: 02/07/2023] Open
Abstract
Productive ribosomal RNA (rRNA) compaction during ribosome assembly necessitates establishing correct tertiary contacts between distant secondary structure elements. Here, we quantify the response of the yeast proteome to low temperature (LT), a condition where aberrant mis-paired RNA folding intermediates accumulate. We show that, at LT, yeast cells globally boost production of their ribosome assembly machinery. We find that the LT-induced assembly factor, Puf6, binds to the nascent catalytic RNA-rich subunit interface within the 60S pre-ribosome, at a site that eventually loads the nuclear export apparatus. Ensemble Förster resonance energy transfer studies show that Puf6 mimics the role of Mg2+ to usher a unique long-range tertiary contact to compact rRNA. At LT, puf6 mutants accumulate 60S pre-ribosomes in the nucleus, thus unveiling Puf6-mediated rRNA compaction as a critical temperature-regulated rescue mechanism that counters rRNA misfolding to prime export competence.
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59
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Bagatelli FFM, de Luna Vitorino FN, da Cunha JPC, Oliveira CC. The ribosome assembly factor Nop53 has a structural role in the formation of nuclear pre-60S intermediates, affecting late maturation events. Nucleic Acids Res 2021; 49:7053-7074. [PMID: 34125911 PMCID: PMC8266606 DOI: 10.1093/nar/gkab494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/18/2021] [Accepted: 05/24/2021] [Indexed: 12/19/2022] Open
Abstract
Eukaryotic ribosome biogenesis is an elaborate process during which ribosomal proteins assemble with the pre-rRNA while it is being processed and folded. Hundreds of assembly factors (AF) are required and transiently recruited to assist the sequential remodeling events. One of the most intricate ones is the stepwise removal of the internal transcribed spacer 2 (ITS2), between the 5.8S and 25S rRNAs, that constitutes together with five AFs the pre-60S ‘foot’. In the transition from nucleolus to nucleoplasm, Nop53 replaces Erb1 at the basis of the foot and recruits the RNA exosome for the ITS2 cleavage and foot disassembly. Here we comprehensively analyze the impact of Nop53 recruitment on the pre-60S compositional changes. We show that depletion of Nop53, different from nop53 mutants lacking the exosome-interacting motif, not only causes retention of the unprocessed foot in late pre-60S intermediates but also affects the transition from nucleolar state E particle to subsequent nuclear stages. Additionally, we reveal that Nop53 depletion causes the impairment of late maturation events such as Yvh1 recruitment. In light of recently described pre-60S cryo-EM structures, our results provide biochemical evidence for the structural role of Nop53 rearranging and stabilizing the foot interface to assist the Nog2 particle formation.
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Affiliation(s)
- Felipe F M Bagatelli
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP 05508-000, Brazil
| | - Francisca N de Luna Vitorino
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, SP 05503-900, Brazil.,Center of Toxins, Immune-Response and Cell Signaling, Butantan Institute, São Paulo, SP 05503-900, Brazil
| | - Julia P C da Cunha
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, SP 05503-900, Brazil.,Center of Toxins, Immune-Response and Cell Signaling, Butantan Institute, São Paulo, SP 05503-900, Brazil
| | - Carla C Oliveira
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP 05508-000, Brazil
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60
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Tartakoff AM, Chen L, Raghavachari S, Gitiforooz D, Dhinakaran A, Ni CL, Pasadyn C, Mahabeleshwar GH, Pasadyn V, Woolford JL. The nucleolus as a polarized coaxial cable in which the rDNA axis is surrounded by dynamic subunit-specific phases. Curr Biol 2021; 31:2507-2519.e4. [PMID: 33862007 PMCID: PMC8222187 DOI: 10.1016/j.cub.2021.03.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 01/18/2021] [Accepted: 03/11/2021] [Indexed: 12/24/2022]
Abstract
In ribosomal DNA (rDNA) repeats, sequences encoding small-subunit (SSU) rRNA precede those encoding large-subunit (LSU) rRNAs. Processing the composite transcript and subunit assembly requires >100 subunit-specific nucleolar assembly factors (AFs). To investigate the functional organization of the nucleolus, we localized AFs in S. cerevisiae in which the rDNA axis was "linearized" to reduce its dimensionality, thereby revealing its coaxial organization. In this situation, rRNA synthesis and processing continue. The axis is embedded in an inner layer/phase of SSU AFs that is surrounded by an outer layer/phase of LSU AFs. When subunit production is inhibited, subsets of AFs differentially relocate between the inner and outer layers, as expected if there is a cycle of repeated relocation whereby "latent" AFs become "operative" when recruited to nascent subunits. Recognition of AF cycling and localization of segments of rRNA make it possible to infer the existence of assembly intermediates that span between the inner and outer layers and to chart the cotranscriptional assembly of each subunit. AF cycling also can explain how having more than one protein phase in the nucleolus makes possible "vectorial 2-phase partitioning" as a driving force for relocation of nascent rRNPs. Because nucleoplasmic AFs are also present in the outer layer, we propose that critical surface remodeling occurs at this site, thereby partitioning subunit precursors into the nucleoplasm for post-transcriptional maturation. Comparison to observations on higher eukaryotes shows that the coaxial paradigm is likely to be applicable for the many other organisms that have rDNA repeats.
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Affiliation(s)
- Alan M Tartakoff
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA.
| | - Lan Chen
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Shashank Raghavachari
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Daria Gitiforooz
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Akshyasri Dhinakaran
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Chun-Lun Ni
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | | | - Ganapati H Mahabeleshwar
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Vanessa Pasadyn
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
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61
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Biallelic splicing variants in the nucleolar 60S assembly factor RBM28 cause the ribosomopathy ANE syndrome. Proc Natl Acad Sci U S A 2021; 118:2017777118. [PMID: 33941690 PMCID: PMC8126767 DOI: 10.1073/pnas.2017777118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Alopecia, neurologic defects, and endocrinopathy (ANE) syndrome is a rare ribosomopathy known to be caused by a p.(Leu351Pro) variant in the essential, conserved, nucleolar large ribosomal subunit (60S) assembly factor RBM28. We report the second family of ANE syndrome to date and a female pediatric ANE syndrome patient. The patient presented with alopecia, craniofacial malformations, hypoplastic pituitary, and hair and skin abnormalities. Unlike the previously reported patients with the p.(Leu351Pro) RBM28 variant, this ANE syndrome patient possesses biallelic precursor messenger RNA (pre-mRNA) splicing variants at the 5' splice sites of exon 5 (ΔE5) and exon 8 (ΔE8) of RBM28 (NM_018077.2:c.[541+1_541+2delinsA]; [946G > T]). In silico analyses and minigene splicing experiments in cells indicate that each splice variant specifically causes skipping of its respective mutant exon. Because the ΔE5 variant results in an in-frame 31 amino acid deletion (p.(Asp150_Lys180del)) in RBM28 while the ΔE8 variant leads to a premature stop codon in exon 9, we predicted that the ΔE5 variant would produce partially functional RBM28 but the ΔE8 variant would not produce functional protein. Using a yeast model, we demonstrate that the ΔE5 variant does indeed lead to reduced overall growth and large subunit ribosomal RNA (rRNA) production and pre-rRNA processing. In contrast, the ΔE8 variant is comparably null, implying that the partially functional ΔE5 RBM28 protein enables survival but precludes correct development. This discovery further defines the underlying molecular pathology of ANE syndrome to include genetic variants that cause aberrant splicing in RBM28 pre-mRNA and highlights the centrality of nucleolar processes in human genetic disease.
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62
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Nikolay R, Hilal T, Schmidt S, Qin B, Schwefel D, Vieira-Vieira CH, Mielke T, Bürger J, Loerke J, Amikura K, Flügel T, Ueda T, Selbach M, Deuerling E, Spahn CMT. Snapshots of native pre-50S ribosomes reveal a biogenesis factor network and evolutionary specialization. Mol Cell 2021; 81:1200-1215.e9. [PMID: 33639093 DOI: 10.1016/j.molcel.2021.02.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 11/11/2020] [Accepted: 02/02/2021] [Indexed: 01/13/2023]
Abstract
Ribosome biogenesis is a fundamental multi-step cellular process that culminates in the formation of ribosomal subunits, whose production and modification are regulated by numerous biogenesis factors. In this study, we analyze physiologic prokaryotic ribosome biogenesis by isolating bona fide pre-50S subunits from an Escherichia coli strain with the biogenesis factor ObgE, affinity tagged at its native gene locus. Our integrative structural approach reveals a network of interacting biogenesis factors consisting of YjgA, RluD, RsfS, and ObgE on the immature pre-50S subunit. In addition, our study provides mechanistic insight into how the GTPase ObgE, in concert with other biogenesis factors, facilitates the maturation of the 50S functional core and reveals both conserved and divergent evolutionary features of ribosome biogenesis between prokaryotes and eukaryotes.
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Affiliation(s)
- Rainer Nikolay
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
| | - Tarek Hilal
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Freie Universität Berlin, Research Centre for Electron Microscopy, Fabeckstr. 36a, 14195 Berlin, Germany
| | - Sabine Schmidt
- Molekulare Mikrobiologie, Universität Konstanz, Konstanz, Germany
| | - Bo Qin
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - David Schwefel
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Carlos H Vieira-Vieira
- Proteome Dynamics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Str. 10, 13125 Berlin, Germany; Faculty of Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany
| | - Thorsten Mielke
- Microscopy and Cryo-Electron Microscopy Service Group, Max Planck Institute for Molecular Genetics, Ihnestr. 63-73, 14195 Berlin, Germany
| | - Jörg Bürger
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Microscopy and Cryo-Electron Microscopy Service Group, Max Planck Institute for Molecular Genetics, Ihnestr. 63-73, 14195 Berlin, Germany
| | - Justus Loerke
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Kazuaki Amikura
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, FSB-401, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Timo Flügel
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Takuya Ueda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, FSB-401, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Matthias Selbach
- Proteome Dynamics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Str. 10, 13125 Berlin, Germany; Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Elke Deuerling
- Molekulare Mikrobiologie, Universität Konstanz, Konstanz, Germany
| | - Christian M T Spahn
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
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63
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Lacoux C, Wacheul L, Saraf K, Pythoud N, Huvelle E, Figaro S, Graille M, Carapito C, Lafontaine DLJ, Heurgué-Hamard V. The catalytic activity of the translation termination factor methyltransferase Mtq2-Trm112 complex is required for large ribosomal subunit biogenesis. Nucleic Acids Res 2020; 48:12310-12325. [PMID: 33166396 PMCID: PMC7708063 DOI: 10.1093/nar/gkaa972] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 10/05/2020] [Accepted: 10/09/2020] [Indexed: 01/14/2023] Open
Abstract
The Mtq2-Trm112 methyltransferase modifies the eukaryotic translation termination factor eRF1 on the glutamine side chain of a universally conserved GGQ motif that is essential for release of newly synthesized peptides. Although this modification is found in the three domains of life, its exact role in eukaryotes remains unknown. As the deletion of MTQ2 leads to severe growth impairment in yeast, we have investigated its role further and tested its putative involvement in ribosome biogenesis. We found that Mtq2 is associated with nuclear 60S subunit precursors, and we demonstrate that its catalytic activity is required for nucleolar release of pre-60S and for efficient production of mature 5.8S and 25S rRNAs. Thus, we identify Mtq2 as a novel ribosome assembly factor important for large ribosomal subunit formation. We propose that Mtq2-Trm112 might modify eRF1 in the nucleus as part of a quality control mechanism aimed at proof-reading the peptidyl transferase center, where it will subsequently bind during translation termination.
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Affiliation(s)
- Caroline Lacoux
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Ludivine Wacheul
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S.-FNRS), Université Libre de Bruxelles Cancer Research Center (U-CRC), Center for Microscopy and Molecular Imaging (CMMI), Gosselies, Belgium
| | - Kritika Saraf
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S.-FNRS), Université Libre de Bruxelles Cancer Research Center (U-CRC), Center for Microscopy and Molecular Imaging (CMMI), Gosselies, Belgium
| | - Nicolas Pythoud
- Laboratoire de Spectrométrie de Masse Bio-Organique (LSMBO), UMR 7178, IPHC, Université de Strasbourg, CNRS, Strasbourg, France
| | - Emmeline Huvelle
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Sabine Figaro
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Marc Graille
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, Institut Polytechnique de Paris, F-91128 Palaiseau, France
| | - Christine Carapito
- Laboratoire de Spectrométrie de Masse Bio-Organique (LSMBO), UMR 7178, IPHC, Université de Strasbourg, CNRS, Strasbourg, France
| | - Denis L J Lafontaine
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S.-FNRS), Université Libre de Bruxelles Cancer Research Center (U-CRC), Center for Microscopy and Molecular Imaging (CMMI), Gosselies, Belgium
| | - Valérie Heurgué-Hamard
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
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64
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Mutational Analysis of the Nsa2 N-Terminus Reveals Its Essential Role in Ribosomal 60S Subunit Assembly. Int J Mol Sci 2020; 21:ijms21239108. [PMID: 33266193 PMCID: PMC7730687 DOI: 10.3390/ijms21239108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 11/23/2020] [Accepted: 11/25/2020] [Indexed: 11/23/2022] Open
Abstract
The ribosome assembly factor Nsa2 is part of the Rea1-Rsa4-Nsa2 interconnected relay on nuclear pre-60S particles that is essential for 60S ribosome biogenesis. Cryo-EM structures depict Nsa2 docked via its C-terminal β-barrel domain to nuclear pre-60S particles, whereas the extended N-terminus, consisting of three α-helical segments, meanders between various 25S rRNA helices with the extreme N-terminus in close vicinity to the Nog1 GTPase center. Here, we tested whether this unappreciated proximity between Nsa2 and Nog1 is of functional importance. Our findings demonstrate that a conservative mutation, Nsa2 Q3N, abolished cell growth and impaired 60S biogenesis. Subsequent genetic and biochemical analyses verified that the Nsa2 N-terminus is required to target Nsa2 to early pre-60S particles. However, overexpression of the Nsa2 N-terminus abolished cytoplasmic recycling of the Nog1 GTPase, and both Nog1 and the Nsa2-N (1-58) construct, but not the respective Nsa2-N (1-58) Q3N mutant, were found arrested on late cytoplasmic pre-60S particles. These findings point to specific roles of the different Nsa2 domains for 60S ribosome biogenesis.
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65
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Moraleva AA, Malysheva MA, Khajdukov SV, Zatsepina OV. A Higher Level of Expression of the Nucleolar Protein SURF6 in Human Normal Activated Lymphocytes and in Lymphocytes of Patients with Lymphoproliferative Disorders. DOKL BIOCHEM BIOPHYS 2020; 494:261-265. [PMID: 33119830 DOI: 10.1134/s1607672920050099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 11/22/2022]
Abstract
Proliferation of mammalian cells is often accompanied by an increase in the content of the nucleolar proteins, which allows researchers to consider such proteins as potential activation markers. To test this assumption experimentally, we examined the expression pattern of the nucleolar rRNA processing factor SURF6 in normal (resting) peripheral blood lymphocytes, lymphocytes activated for proliferation in vitro, and in blood samples from patients with lymphoproliferative diseases. Using two methods (immunofluorescence and immunoblotting), we for the first time showed that the SURF6 protein is not detected in normal lymphocytes but can easily be visualized in lymphocytes after PHA activation and in lymphocytes of lymphocytic leukemia patients. The level of SURF6 expression in patients correlated with the aggressiveness of the disease development determined by the content of Ki-67-positive lymphocytes. These results allow the SURF6 nucleolar protein to be considered as a putative activation marker of lymphocytes in human blood disorders.
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Affiliation(s)
- A A Moraleva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
| | - M A Malysheva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
| | - S V Khajdukov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
| | - O V Zatsepina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia.
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66
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Structural insights into assembly of the ribosomal nascent polypeptide exit tunnel. Nat Commun 2020; 11:5111. [PMID: 33037216 PMCID: PMC7547690 DOI: 10.1038/s41467-020-18878-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 09/14/2020] [Indexed: 11/08/2022] Open
Abstract
The nascent polypeptide exit tunnel (NPET) is a major functional center of 60S ribosomal subunits. However, little is known about how the NPET is constructed during ribosome assembly. We utilized molecular genetics, biochemistry, and cryo-electron microscopy (cryo-EM) to investigate the functions of two NPET-associated proteins, ribosomal protein uL4 and assembly factor Nog1, in NPET assembly. Structures of mutant pre-ribosomes lacking the tunnel domain of uL4 reveal a misassembled NPET, including an aberrantly flexible ribosomal RNA helix 74, resulting in at least three different blocks in 60S assembly. Structures of pre-ribosomes lacking the C-terminal extension of Nog1 demonstrate that this extension scaffolds the tunnel domain of uL4 in the NPET to help maintain stability in the core of pre-60S subunits. Our data reveal that uL4 and Nog1 work together in the maturation of ribosomal RNA helix 74, which is required to ensure proper construction of the NPET and 60S ribosomal subunits. The nascent polypeptide exit tunnel (NPET) is a functional center of the large ribosomal subunit through which the nascent polypeptide chains travel from the peptidyltransferase center (PTC). Here the authors provide structural insight into NPET maturation and how it is linked to other aspects of ribosome biogenesis.
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67
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Zhang W, Tian W, Gao Z, Wang G, Zhao H. Phylogenetic Utility of rRNA ITS2 Sequence-Structure under Functional Constraint. Int J Mol Sci 2020; 21:ijms21176395. [PMID: 32899108 PMCID: PMC7504139 DOI: 10.3390/ijms21176395] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 02/07/2023] Open
Abstract
The crucial function of the internal transcribed spacer 2 (ITS2) region in ribosome biogenesis depends on its secondary and tertiary structures. Despite rapidly evolving, ITS2 is under evolutionary constraints to maintain the specific secondary structures that provide functionality. A link between function, structure and evolution could contribute an understanding to each other and recently has created a growing point of sequence-structure phylogeny of ITS2. Here we briefly review the current knowledge of ITS2 processing in ribosome biogenesis, focusing on the conservative characteristics of ITS2 secondary structure, including structure form, structural motifs, cleavage sites, and base-pair interactions. We then review the phylogenetic implications and applications of this structure information, including structure-guiding sequence alignment, base-pair mutation model, and species distinguishing. We give the rationale for why incorporating structure information into tree construction could improve reliability and accuracy, and some perspectives of bioinformatics coding that allow for a meaningful evolutionary character to be extracted. In sum, this review of the integration of function, structure and evolution of ITS2 will expand the traditional sequence-based ITS2 phylogeny and thus contributes to the tree of life. The generality of ITS2 characteristics may also inspire phylogenetic use of other similar structural regions.
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Affiliation(s)
- Wei Zhang
- Marine College, Shandong University, Weihai 264209, China; (Z.G.); (G.W.); (H.Z.)
- Correspondence: ; Tel.: +86-631-5688-303
| | - Wen Tian
- State Key Laboratory of Ballast Water Research, Comprehensive Technical Service Center of Jiangyin Customs, Jiangyin 214440, China;
| | - Zhipeng Gao
- Marine College, Shandong University, Weihai 264209, China; (Z.G.); (G.W.); (H.Z.)
| | - Guoli Wang
- Marine College, Shandong University, Weihai 264209, China; (Z.G.); (G.W.); (H.Z.)
| | - Hong Zhao
- Marine College, Shandong University, Weihai 264209, China; (Z.G.); (G.W.); (H.Z.)
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68
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Micic J, Li Y, Wu S, Wilson D, Tutuncuoglu B, Gao N, Woolford JL. Coupling of 5S RNP rotation with maturation of functional centers during large ribosomal subunit assembly. Nat Commun 2020; 11:3751. [PMID: 32719344 PMCID: PMC7385084 DOI: 10.1038/s41467-020-17534-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 06/29/2020] [Indexed: 12/29/2022] Open
Abstract
The protein composition and structure of assembling 60S ribosomal subunits undergo numerous changes as pre-ribosomes transition from the nucleolus to the nucleoplasm. This includes stable anchoring of the Rpf2 subcomplex containing 5S rRNA, rpL5, rpL11, Rpf2 and Rrs1, which initially docks onto the flexible domain V of rRNA at earlier stages of assembly. In this work, we tested the function of the C-terminal domain (CTD) of Rpf2 during these anchoring steps, by truncating this extension and assaying effects on middle stages of subunit maturation. The rpf2Δ255-344 mutation affects proper folding of rRNA helices H68-70 during anchoring of the Rpf2 subcomplex. In addition, several assembly factors (AFs) are absent from pre-ribosomes or in altered conformations. Consequently, major remodeling events fail to occur: rotation of the 5S RNP, maturation of the peptidyl transferase center (PTC) and the nascent polypeptide exit tunnel (NPET), and export of assembling subunits to the cytoplasm. As assembling 60S subunits transit from the nucleolus to the nucleoplasm, they undergo significant changes in protein composition and structure. Here, the authors provide a structural view of interconnected events during the middle steps of assembly that include the maturation of the central protuberance, the peptidyltransferase center and the nascent polypeptide exit tunnel.
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Affiliation(s)
- Jelena Micic
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Yu Li
- State Key Laboratory of Membrane Biology, School of Life Science, Tsinghua University, Beijing, China.,Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, Beijing, China
| | - Shan Wu
- State Key Laboratory of Membrane Biology, School of Life Science, Tsinghua University, Beijing, China.,State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, School of Life Sciences, Hubei University, Wuhan, China
| | - Daniel Wilson
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Beril Tutuncuoglu
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China.
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA.
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69
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Liang X, Zuo MQ, Zhang Y, Li N, Ma C, Dong MQ, Gao N. Structural snapshots of human pre-60S ribosomal particles before and after nuclear export. Nat Commun 2020; 11:3542. [PMID: 32669547 PMCID: PMC7363849 DOI: 10.1038/s41467-020-17237-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 06/19/2020] [Indexed: 12/11/2022] Open
Abstract
Ribosome biogenesis is an elaborate and energetically expensive program that involve two hundred protein factors in eukaryotes. Nuclear export of pre-ribosomal particles is one central step which also serves as an internal structural checkpoint to ensure the proper completion of nuclear assembly events. Here we present four structures of human pre-60S particles isolated through a nuclear export factor NMD3, representing assembly stages immediately before and after nuclear export. These structures reveal locations of a dozen of human factors, including an uncharacterized factor TMA16 localized between the 5S RNA and the P0 stalk. Comparison of these structures shows a progressive maturation for the functional regions, such as peptidyl transferase centre and peptide exit tunnel, and illustrate a sequence of factor-assisted rRNA maturation events. These data facilitate our understanding of the global conservation of ribosome assembly in eukaryotes and species-specific features of human assembly factors.
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MESH Headings
- Cell Nucleus/metabolism
- Cryoelectron Microscopy
- Humans
- Models, Molecular
- RNA, Ribosomal, 5S/isolation & purification
- RNA, Ribosomal, 5S/metabolism
- RNA, Ribosomal, 5S/ultrastructure
- RNA-Binding Proteins/isolation & purification
- RNA-Binding Proteins/metabolism
- RNA-Binding Proteins/ultrastructure
- Ribosomal Proteins/isolation & purification
- Ribosomal Proteins/metabolism
- Ribosomal Proteins/ultrastructure
- Ribosome Subunits, Large, Eukaryotic/metabolism
- Ribosome Subunits, Large, Eukaryotic/ultrastructure
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Affiliation(s)
- Xiaomeng Liang
- State Key Laboratory of Membrane Biology, School of Life Science, Tsinghua University, 100084, Beijing, China
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Mei-Qing Zuo
- College of Biological Sciences, China Agricultural University, 100193, Beijing, China
- National Institute of Biological Sciences, 102206, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 100084, Beijing, China
| | - Yunyang Zhang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Ningning Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Chengying Ma
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, 102206, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 100084, Beijing, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, 100871, Beijing, China.
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70
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Kater L, Mitterer V, Thoms M, Cheng J, Berninghausen O, Beckmann R, Hurt E. Construction of the Central Protuberance and L1 Stalk during 60S Subunit Biogenesis. Mol Cell 2020; 79:615-628.e5. [PMID: 32668200 DOI: 10.1016/j.molcel.2020.06.032] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 05/13/2020] [Accepted: 06/18/2020] [Indexed: 12/15/2022]
Abstract
Ribosome assembly is driven by numerous assembly factors, including the Rix1 complex and the AAA ATPase Rea1. These two assembly factors catalyze 60S maturation at two distinct states, triggering poorly understood large-scale structural transitions that we analyzed by cryo-electron microscopy. Two nuclear pre-60S intermediates were discovered that represent previously unknown states after Rea1-mediated removal of the Ytm1-Erb1 complex and reveal how the L1 stalk develops from a pre-mature nucleolar to a mature-like nucleoplasmic state. A later pre-60S intermediate shows how the central protuberance arises, assisted by the nearby Rix1-Rea1 machinery, which was solved in its pre-ribosomal context to molecular resolution. This revealed a Rix12-Ipi32 tetramer anchored to the pre-60S via Ipi1, strategically positioned to monitor this decisive remodeling. These results are consistent with a general underlying principle that temporarily stabilized immature RNA domains are successively remodeled by assembly factors, thereby ensuring failsafe assembly progression.
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Affiliation(s)
- Lukas Kater
- Gene Center Munich and Center of Integrated Protein Science-Munich (CiPS-M), Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany
| | - Valentin Mitterer
- Biochemie-Zentrum der Universität Heidelberg, 69120 Heidelberg, Germany
| | - Matthias Thoms
- Gene Center Munich and Center of Integrated Protein Science-Munich (CiPS-M), Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany; Biochemie-Zentrum der Universität Heidelberg, 69120 Heidelberg, Germany
| | - Jingdong Cheng
- Gene Center Munich and Center of Integrated Protein Science-Munich (CiPS-M), Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany
| | - Otto Berninghausen
- Gene Center Munich and Center of Integrated Protein Science-Munich (CiPS-M), Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany
| | - Roland Beckmann
- Gene Center Munich and Center of Integrated Protein Science-Munich (CiPS-M), Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany.
| | - Ed Hurt
- Biochemie-Zentrum der Universität Heidelberg, 69120 Heidelberg, Germany.
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71
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Yasmin R, Kaur I, Tuteja R. Plasmodium falciparum DDX55 is a nucleocytoplasmic protein and a 3'-5' direction-specific DNA helicase. PROTOPLASMA 2020; 257:1049-1067. [PMID: 32125511 DOI: 10.1007/s00709-020-01495-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 02/19/2020] [Indexed: 06/10/2023]
Abstract
Malaria is one of the major causes of mortality as well as morbidity in many tropical and subtropical countries around the world. Although artemisinin combination therapies (ACTs) are contributing to substantial decline in the worldwide malaria burden, it is becoming vulnerable by the emergence of artemisinin resistance in Plasmodium falciparum leading to clinical failure of ACTs in Southeast Asia. Helicases play important role in nucleic acid metabolic processes and have been also identified as therapeutic drug target for different diseases. Previously, it has been reported that P. falciparum contains a group of DEAD-box family of helicases which are homologous to Has1 family of yeast. Here, we present the characterization of a member of Has1 family (PlasmoDB number PF3D7_1419100) named as PfDDX55. The biochemical characterization of PfDDX55C revealed that it contains both DNA- and RNA-dependent ATPase activity. PfDDX55C unwinds partially duplex DNA in 3' to 5' direction and utilizes mainly ATP or dATP for its activity. The immunofluorescence assay and q-RT PCR analysis show that PfDDX55 is a nucleocytoplasmic protein expressed in all the intraerythrocytic development of P. falciparum 3D7 strain with maximum expression level in trophozoite stage. The LC-MS/MS experiment results and STRING analysis show that PfDDX55 interacts with AAA-ATPase which has been shown to be involved in ribosomal biogenesis.
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Affiliation(s)
- Rahena Yasmin
- Parasite Biology Group, ICGEB, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Inderjeet Kaur
- Malaria Biology Group, ICGEB, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Renu Tuteja
- Parasite Biology Group, ICGEB, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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72
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From Snapshots to Flipbook-Resolving the Dynamics of Ribosome Biogenesis with Chemical Probes. Int J Mol Sci 2020; 21:ijms21082998. [PMID: 32340379 PMCID: PMC7215809 DOI: 10.3390/ijms21082998] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/17/2020] [Accepted: 04/22/2020] [Indexed: 12/27/2022] Open
Abstract
The synthesis of ribosomes is one of the central and most resource demanding processes in each living cell. As ribosome biogenesis is tightly linked with the regulation of the cell cycle, perturbation of ribosome formation can trigger severe diseases, including cancer. Eukaryotic ribosome biogenesis starts in the nucleolus with pre-rRNA transcription and the initial assembly steps, continues in the nucleoplasm and is finished in the cytoplasm. From start to end, this process is highly dynamic and finished within few minutes. Despite the tremendous progress made during the last decade, the coordination of the individual maturation steps is hard to unravel by a conventional methodology. In recent years small molecular compounds were identified that specifically block either rDNA transcription or distinct steps within the maturation pathway. As these inhibitors diffuse into the cell rapidly and block their target proteins within seconds, they represent excellent tools to investigate ribosome biogenesis. Here we review how the inhibitors affect ribosome biogenesis and discuss how these effects can be interpreted by taking the complex self-regulatory mechanisms of the pathway into account. With this we want to highlight the potential of low molecular weight inhibitors to approach the dynamic nature of the ribosome biogenesis pathway.
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73
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Braun CM, Hackert P, Schmid CE, Bohnsack MT, Bohnsack KE, Perez-Fernandez J. Pol5 is required for recycling of small subunit biogenesis factors and for formation of the peptide exit tunnel of the large ribosomal subunit. Nucleic Acids Res 2020; 48:405-420. [PMID: 31745560 PMCID: PMC7145529 DOI: 10.1093/nar/gkz1079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 10/29/2019] [Accepted: 11/04/2019] [Indexed: 01/24/2023] Open
Abstract
More than 200 assembly factors (AFs) are required for the production of ribosomes in yeast. The stepwise association and dissociation of these AFs with the pre-ribosomal subunits occurs in a hierarchical manner to ensure correct maturation of the pre-rRNAs and assembly of the ribosomal proteins. Although decades of research have provided a wealth of insights into the functions of many AFs, others remain poorly characterized. Pol5 was initially classified with B-type DNA polymerases, however, several lines of evidence indicate the involvement of this protein in ribosome assembly. Here, we show that depletion of Pol5 affects the processing of pre-rRNAs destined for the both the large and small subunits. Furthermore, we identify binding sites for Pol5 in the 5' external transcribed spacer and within domain III of the 25S rRNA sequence. Consistent with this, we reveal that Pol5 is required for recruitment of ribosomal proteins that form the polypeptide exit tunnel in the LSU and that depletion of Pol5 impairs the release of 5' ETS fragments from early pre-40S particles. The dual functions of Pol5 in 60S assembly and recycling of pre-40S AFs suggest that this factor could contribute to ensuring the stoichiometric production of ribosomal subunits.
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Affiliation(s)
- Christina M Braun
- Department of Biochemistry III, University of Regensburg, Universitätstrasse 31, 93053 Regensburg, Germany
| | - Philipp Hackert
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Catharina E Schmid
- Department of Biochemistry III, University of Regensburg, Universitätstrasse 31, 93053 Regensburg, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany.,Göttingen Center for Molecular Biosciences, Georg-August University, Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Jorge Perez-Fernandez
- Department of Biochemistry III, University of Regensburg, Universitätstrasse 31, 93053 Regensburg, Germany
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74
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Ebright RY, Lee S, Wittner BS, Niederhoffer KL, Nicholson BT, Bardia A, Truesdell S, Wiley DF, Wesley B, Li S, Mai A, Aceto N, Vincent-Jordan N, Szabolcs A, Chirn B, Kreuzer J, Comaills V, Kalinich M, Haas W, Ting DT, Toner M, Vasudevan S, Haber DA, Maheswaran S, Micalizzi DS. Deregulation of ribosomal protein expression and translation promotes breast cancer metastasis. Science 2020; 367:1468-1473. [PMID: 32029688 DOI: 10.1126/science.aay0939] [Citation(s) in RCA: 188] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 12/01/2019] [Accepted: 01/26/2020] [Indexed: 12/11/2022]
Abstract
Circulating tumor cells (CTCs) are shed into the bloodstream from primary tumors, but only a small subset of these cells generates metastases. We conducted an in vivo genome-wide CRISPR activation screen in CTCs from breast cancer patients to identify genes that promote distant metastasis in mice. Genes coding for ribosomal proteins and regulators of translation were enriched in this screen. Overexpression of RPL15, which encodes a component of the large ribosomal subunit, increased metastatic growth in multiple organs and selectively enhanced translation of other ribosomal proteins and cell cycle regulators. RNA sequencing of freshly isolated CTCs from breast cancer patients revealed a subset with strong ribosome and protein synthesis signatures; these CTCs expressed proliferation and epithelial markers and correlated with poor clinical outcome. Therapies targeting this aggressive subset of CTCs may merit exploration as potential suppressors of metastatic progression.
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Affiliation(s)
- Richard Y Ebright
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Sooncheol Lee
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Ben S Wittner
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Kira L Niederhoffer
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Benjamin T Nicholson
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Aditya Bardia
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA.,Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Samuel Truesdell
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Devon F Wiley
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Benjamin Wesley
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Selena Li
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Andy Mai
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Nicola Aceto
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Nicole Vincent-Jordan
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Annamaria Szabolcs
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Brian Chirn
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Johannes Kreuzer
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Valentine Comaills
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Mark Kalinich
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Wilhelm Haas
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA.,Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - David T Ting
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA.,Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Mehmet Toner
- Center for Bioengineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.,Shriners Hospital for Children, Boston, MA 02114, USA.,Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Shobha Vasudevan
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA.,Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Daniel A Haber
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA. .,Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02114, USA
| | - Shyamala Maheswaran
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA. .,Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Douglas S Micalizzi
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA.,Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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75
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Davila Gallesio J, Hackert P, Bohnsack KE, Bohnsack MT. Sgd1 is an MIF4G domain-containing cofactor of the RNA helicase Fal1 and associates with the 5' domain of the 18S rRNA sequence. RNA Biol 2020; 17:539-553. [PMID: 31994962 PMCID: PMC7237134 DOI: 10.1080/15476286.2020.1716540] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Assembly of eukaryotic ribosomal subunits is a complex and dynamic process involving the action of more than 200 trans-acting assembly factors. Although recent cryo-electron microscopy structures have provided information on architecture of several pre-ribosomal particles and the binding sites of many AFs, the RNA and protein interactions of many other AFs not captured in these snapshots still remain elusive. RNA helicases are key regulators of structural rearrangements within pre-ribosomal complexes and here we have analysed the eIF4A-like RNA helicase Fal1 and its putative cofactor Sgd1. Our data show that these proteins interact directly via the MIF4G domain of Sgd1 and that the MIF4G domain of Sgd1 stimulates the catalytic activity of Fal1 in vitro. The catalytic activity of Fal1, and the interaction between Fal1 and Sgd1, are required for efficient pre-rRNA processing at the A0, A1 and A2 sites. Furthermore, Sgd1 co-purifies the early small subunit biogenesis factors Lcp5 and Rok1, suggesting that the Fal1-Sgd1 complex likely functions within the SSU processome. In vivo crosslinking data reveal that Sgd1 binds to helix H12 of the 18S rRNA sequence and we further demonstrate that this interaction is formed by the C-terminal region of the protein, which is essential for its function in ribosome biogenesis.
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Affiliation(s)
- Jimena Davila Gallesio
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Philipp Hackert
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany.,Göttingen Center for Molecular Biosciences, Georg-August University, Göttingen, Germany
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76
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Klingauf-Nerurkar P, Gillet LC, Portugal-Calisto D, Oborská-Oplová M, Jäger M, Schubert OT, Pisano A, Peña C, Rao S, Altvater M, Chang Y, Aebersold R, Panse VG. The GTPase Nog1 co-ordinates the assembly, maturation and quality control of distant ribosomal functional centers. eLife 2020; 9:e52474. [PMID: 31909713 PMCID: PMC6968927 DOI: 10.7554/elife.52474] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 12/20/2019] [Indexed: 01/08/2023] Open
Abstract
Eukaryotic ribosome precursors acquire translation competence in the cytoplasm through stepwise release of bound assembly factors, and proofreading of their functional centers. In case of the pre-60S, these steps include removal of placeholders Rlp24, Arx1 and Mrt4 that prevent premature loading of the ribosomal protein eL24, the protein-folding machinery at the polypeptide exit tunnel (PET), and the ribosomal stalk, respectively. Here, we reveal that sequential ATPase and GTPase activities license release factors Rei1 and Yvh1 to trigger Arx1 and Mrt4 removal. Drg1-ATPase activity removes Rlp24 from the GTPase Nog1 on the pre-60S; consequently, the C-terminal tail of Nog1 is extracted from the PET. These events enable Rei1 to probe PET integrity and catalyze Arx1 release. Concomitantly, Nog1 eviction from the pre-60S permits peptidyl transferase center maturation, and allows Yvh1 to mediate Mrt4 release for stalk assembly. Thus, Nog1 co-ordinates the assembly, maturation and quality control of distant functional centers during ribosome formation.
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Affiliation(s)
| | - Ludovic C Gillet
- Institute of Molecular Systems BiologyETH ZurichZurichSwitzerland
| | | | - Michaela Oborská-Oplová
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
- Institute of BiochemistryETH ZurichZurichSwitzerland
| | - Martin Jäger
- Institute of BiochemistryETH ZurichZurichSwitzerland
| | - Olga T Schubert
- Institute of Molecular Systems BiologyETH ZurichZurichSwitzerland
| | - Agnese Pisano
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
| | - Cohue Peña
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
| | - Sanjana Rao
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
| | | | - Yiming Chang
- Institute of BiochemistryETH ZurichZurichSwitzerland
| | - Ruedi Aebersold
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
- Institute of Molecular Systems BiologyETH ZurichZurichSwitzerland
| | - Vikram G Panse
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
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77
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Tang D, Shi X, Guo H, Bai Y, Shen C, Zhang Y, Wang Z. Comparative transcriptome analysis of the gills of Procambarus clarkii provides novel insights into the immune-related mechanism of copper stress tolerance. FISH & SHELLFISH IMMUNOLOGY 2020; 96:32-40. [PMID: 31786343 DOI: 10.1016/j.fsi.2019.11.060] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/19/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
The red-swamp crayfish (Procambarus clarkii) is the most important economic shrimp species in China, and is an important model crustacean organism in many fields of research. In crustaceans, gills interface directly with the ambient environment and thus play a vital role in the toxicology. In the context of increasing environmental heavy metal pollution, the relationship between copper (Cu2+) stress and the immune response of P. clarkii has recently received considerable attention. However, impact of Cu2+ on the crayfish immune system is still not fully understood. In this study, we used Illumina sequencing technology to perform a transcriptome analysis of the gills of P. clarkii after 24 h of Cu2+ treatment. A total of 37,226,812 unigenes were assembled, and 1943 unigenes were significantly differentially expressed between the control and Cu2+ treatment groups. Functional categorization of differentially expressed genes (DEGs) revealed that genes related to antioxidant activity, detoxication, metabolic processes, biosynthetic processes, and immune system processes were differentially regulated during Cu2+ stress. In addition, DEGs in the immune system were classified as being related to the MAPK signaling pathway, purine metabolism, Toll and Imd signaling pathway, PI3K-Akt signaling pathway and Hippo signaling pathway. Five genes (CuZnSOD, CAT, IDH1, PHYH and DECR2) were significantly up-regulated in the peroxisome pathway, which plays an important role in reacting to oxidative stress. Importantly, qRT-PCR validation of the results for seven genes chosen at random (NDK, ATP6L, ATP5C1, RPS14, RPL22e, CTSF and HSP90A) confirmed the Illumina sequencing results. This study provides a valuable starting point for further studies to elucidate the molecular basis of the immune system's response to Cu2+ stress in crayfish.
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Affiliation(s)
- Dan Tang
- Jiangsu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-agriculture, Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, School of Ocean and Biological Engineering, Yancheng Teachers University, Yancheng, 224001, Jiangsu Province, People's Republic of China
| | - Xueling Shi
- Jiangsu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-agriculture, Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, School of Ocean and Biological Engineering, Yancheng Teachers University, Yancheng, 224001, Jiangsu Province, People's Republic of China
| | - Huayun Guo
- Jiangsu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-agriculture, Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, School of Ocean and Biological Engineering, Yancheng Teachers University, Yancheng, 224001, Jiangsu Province, People's Republic of China
| | - Yuze Bai
- Jiangsu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-agriculture, Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, School of Ocean and Biological Engineering, Yancheng Teachers University, Yancheng, 224001, Jiangsu Province, People's Republic of China
| | - Chenchen Shen
- Jiangsu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-agriculture, Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, School of Ocean and Biological Engineering, Yancheng Teachers University, Yancheng, 224001, Jiangsu Province, People's Republic of China
| | - Yiping Zhang
- Jiangsu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-agriculture, Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, School of Ocean and Biological Engineering, Yancheng Teachers University, Yancheng, 224001, Jiangsu Province, People's Republic of China
| | - Zhengfei Wang
- Jiangsu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-agriculture, Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, School of Ocean and Biological Engineering, Yancheng Teachers University, Yancheng, 224001, Jiangsu Province, People's Republic of China.
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78
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Xiang Y, Shen Z, Shi Y. Chemical Cross-Linking and Mass Spectrometric Analysis of the Endogenous Yeast Exosome Complexes. Methods Mol Biol 2020; 2062:383-400. [PMID: 31768986 DOI: 10.1007/978-1-4939-9822-7_18] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Chemical cross-linking and mass spectrometric readout (CX-MS) has become a useful toolkit for structural analysis of protein complexes. CX-MS enables rapid detection of a larger number of cross-link peptides from the chemically cross-linked protein assembly, providing invaluable cross-link spatial restraints to understand the architecture of the complex. Since CX-MS is complementary with other structural and computational modeling tools, it can be used for integrative structural determination of large native protein assemblies. However, due to technical limitations, current CX-MS applications have still been predominantly confined to complexes reconstituted from recombinant proteins where large amount of purified materials are available. Cross-linking and hybrid structural proteomic analysis of endogenous protein complexes remains a challenge. In this chapter, we present a protocol that efficiently couples affinity capture of endogenous complexes with sensitive CX-MS analysis, with particular application to the yeast RNA processing exosome complexes.
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Affiliation(s)
- Yufei Xiang
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Zhuolun Shen
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- School of Medicine, Tsinghua University, Beijing, China
| | - Yi Shi
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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79
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Abstract
In the past 25 years, genetic and biochemical analyses of ribosome assembly in yeast have identified most of the factors that participate in this complex pathway and have generated models for the mechanisms driving the assembly. More recently, the publication of numerous cryo-electron microscopy structures of yeast ribosome assembly intermediates has provided near-atomic resolution snapshots of ribosome precursor particles. Satisfyingly, these structural data support the genetic and biochemical models and provide additional mechanistic insight into ribosome assembly. In this Review, we discuss the mechanisms of assembly of the yeast small ribosomal subunit and large ribosomal subunit in the nucleolus, nucleus and cytoplasm. Particular emphasis is placed on concepts such as the mechanisms of RNA compaction, the functions of molecular switches and molecular mimicry, the irreversibility of assembly checkpoints and the roles of structural and functional proofreading of pre-ribosomal particles.
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80
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Gnanasundram SV, Kos-Braun IC, Koš M. At least two molecules of the RNA helicase Has1 are simultaneously present in pre-ribosomes during ribosome biogenesis. Nucleic Acids Res 2019; 47:10852-10864. [PMID: 31511893 PMCID: PMC6846684 DOI: 10.1093/nar/gkz767] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 08/20/2019] [Accepted: 08/22/2019] [Indexed: 11/20/2022] Open
Abstract
The RNA helicase Has1 is involved in the biogenesis of both small and large ribosomal subunits. How it performs these separate roles is not fully understood. Here we provide evidence that at least two molecules of Has1 are temporarily present at the same time in 90S pre-ribosomes. We identified multiple Has1 binding sites in the 18S, 5.8S and 25S rRNAs. We show that while the Has1 catalytic activity is not required for binding to 5.8S/25S region in pre-rRNA, it is essential for binding to 18S sites. After the cleavage of pre-rRNA at the A2 site, Has1 remains associated not only with pre-60S but, unexpectedly, also with pre-40S ribosomes. The recruitment to 90S/pre-40S and pre-60S ribosomes is mutually independent. Our data provides insight into how Has1 performs its separate functions in the synthesis of both ribosomal subunits.
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Affiliation(s)
- Sivakumar Vadivel Gnanasundram
- Biochemistry Center, University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
- Inserm UMR1131, Institute Universitaire d’Hématologie, Hôpital St. Louis, F-75010 Paris, France
| | - Isabelle C Kos-Braun
- Biochemistry Center, University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Martin Koš
- Biochemistry Center, University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
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81
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Shaping the Nascent Ribosome: AAA-ATPases in Eukaryotic Ribosome Biogenesis. Biomolecules 2019; 9:biom9110715. [PMID: 31703473 PMCID: PMC6920918 DOI: 10.3390/biom9110715] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/04/2019] [Accepted: 11/05/2019] [Indexed: 02/08/2023] Open
Abstract
AAA-ATPases are molecular engines evolutionarily optimized for the remodeling of proteins and macromolecular assemblies. Three AAA-ATPases are currently known to be involved in the remodeling of the eukaryotic ribosome, a megadalton range ribonucleoprotein complex responsible for the translation of mRNAs into proteins. The correct assembly of the ribosome is performed by a plethora of additional and transiently acting pre-ribosome maturation factors that act in a timely and spatially orchestrated manner. Minimal disorder of the assembly cascade prohibits the formation of functional ribosomes and results in defects in proliferation and growth. Rix7, Rea1, and Drg1, which are well conserved across eukaryotes, are involved in different maturation steps of pre-60S ribosomal particles. These AAA-ATPases provide energy for the efficient removal of specific assembly factors from pre-60S particles after they have fulfilled their function in the maturation cascade. Recent structural and functional insights have provided the first glimpse into the molecular mechanism of target recognition and remodeling by Rix7, Rea1, and Drg1. Here we summarize current knowledge on the AAA-ATPases involved in eukaryotic ribosome biogenesis. We highlight the latest insights into their mechanism of mechano-chemical complex remodeling driven by advanced cryo-EM structures and the use of highly specific AAA inhibitors.
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82
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Ramos-Sáenz A, González-Álvarez D, Rodríguez-Galán O, Rodríguez-Gil A, Gaspar SG, Villalobo E, Dosil M, de la Cruz J. Pol5 is an essential ribosome biogenesis factor required for 60S ribosomal subunit maturation in Saccharomyces cerevisiae. RNA (NEW YORK, N.Y.) 2019; 25:1561-1575. [PMID: 31413149 PMCID: PMC6795146 DOI: 10.1261/rna.072116.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 08/08/2019] [Indexed: 06/10/2023]
Abstract
In Saccharomyces cerevisiae, more than 250 trans-acting factors are involved in the maturation of 40S and 60S ribosomal subunits. The expression of most of these factors is transcriptionally coregulated to ensure correct ribosome production under a wide variety of environmental and intracellular conditions. Here, we identified the essential nucleolar Pol5 protein as a novel trans-acting factor required for the synthesis of 60S ribosomal subunits. Pol5 weakly and/or transiently associates with early to medium pre-60S ribosomal particles. Depletion of and temperature-sensitive mutations in Pol5 result in a deficiency of 60S ribosomal subunits and accumulation of half-mer polysomes. Both processing of 27SB pre-rRNA to mature 25S rRNA and release of pre-60S ribosomal particles from the nucle(ol)us to the cytoplasm are impaired in the Pol5-depleted strain. Moreover, we identified the genes encoding ribosomal proteins uL23 and eL27A as multicopy suppressors of the slow growth of a temperature-sensitive pol5 mutant. These results suggest that Pol5 could function in ensuring the correct folding of 25S rRNA domain III; thus, favoring the correct assembly of these two ribosomal proteins at their respective binding sites into medium pre-60S ribosomal particles. Pol5 is homologous to the human tumor suppressor Myb-binding protein 1A (MYBBP1A). However, expression of MYBBP1A failed to complement the lethal phenotype of a pol5 null mutant strain though interfered with 60S ribosomal subunit biogenesis.
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Affiliation(s)
- Ana Ramos-Sáenz
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, E-41013, Seville, Spain
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, E-41012, Seville, Spain
| | - Daniel González-Álvarez
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, E-41013, Seville, Spain
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, E-41012, Seville, Spain
| | - Olga Rodríguez-Galán
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, E-41013, Seville, Spain
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, E-41012, Seville, Spain
| | - Alfonso Rodríguez-Gil
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, E-41013, Seville, Spain
| | - Sonia G Gaspar
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, CSIC-Universidad de Salamanca, E-37007, Salamanca, Spain
- Centro de Investigación Biomédica en Red en Cáncer (CIBERONC), CSIC-Universidad de Salamanca, E-37007, Salamanca, Spain
| | - Eduardo Villalobo
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, E-41013, Seville, Spain
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, E-41012, Seville, Spain
| | - Mercedes Dosil
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, CSIC-Universidad de Salamanca, E-37007, Salamanca, Spain
- Centro de Investigación Biomédica en Red en Cáncer (CIBERONC), CSIC-Universidad de Salamanca, E-37007, Salamanca, Spain
- Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, E-37007, Salamanca, Spain
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, E-41013, Seville, Spain
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, E-41012, Seville, Spain
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83
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Cepeda LPP, Bagatelli FFM, Santos RM, Santos MDM, Nogueira FCS, Oliveira CC. The ribosome assembly factor Nop53 controls association of the RNA exosome with pre-60S particles in yeast. J Biol Chem 2019; 294:19365-19380. [PMID: 31662437 DOI: 10.1074/jbc.ra119.010193] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/22/2019] [Indexed: 12/24/2022] Open
Abstract
Eukaryotic ribosomal biogenesis is a high-energy-demanding and complex process that requires hundreds of trans-acting factors to dynamically build the highly-organized 40S and 60S subunits. Each ribonucleoprotein complex comprises specific rRNAs and ribosomal proteins that are organized into functional domains. The RNA exosome complex plays a crucial role as one of the pre-60S-processing factors, because it is the RNase responsible for processing the 7S pre-rRNA to the mature 5.8S rRNA. The yeast pre-60S assembly factor Nop53 has previously been shown to associate with the nucleoplasmic pre-60S in a region containing the "foot" structure assembled around the 3' end of the 7S pre-rRNA. Nop53 interacts with 25S rRNA and with several 60S assembly factors, including the RNA exosome, specifically, with its catalytic subunit Rrp6 and with the exosome-associated RNA helicase Mtr4. Nop53 is therefore considered the adaptor responsible for recruiting the exosome complex for 7S processing. Here, using proteomics-based approaches in budding yeast to analyze the effects of Nop53 on the exosome interactome, we found that the exosome binds pre-ribosomal complexes early during the ribosome maturation pathway. We also identified interactions through which Nop53 modulates exosome activity in the context of 60S maturation and provide evidence that in addition to recruiting the exosome, Nop53 may also be important for positioning the exosome during 7S processing. On the basis of these findings, we propose that the exosome is recruited much earlier during ribosome assembly than previously thought, suggesting the existence of additional interactions that remain to be described.
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Affiliation(s)
- Leidy Paola P Cepeda
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, 05508-000 São Paulo, SP, Brazil
| | - Felipe F M Bagatelli
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, 05508-000 São Paulo, SP, Brazil
| | - Renata M Santos
- Proteomics Unit and Laboratory of Proteomics/LADETEC, Federal University of Rio de Janeiro, 22410-001 Rio de Janeiro (RJ), Brazil
| | - Marlon D M Santos
- Laboratory for Structural and Computational Proteomics, Carlos Chagas Institute, Fiocruz, Curitiba, PR, CEP 81350-010, Brazil
| | - Fabio C S Nogueira
- Proteomics Unit and Laboratory of Proteomics/LADETEC, Federal University of Rio de Janeiro, 22410-001 Rio de Janeiro (RJ), Brazil
| | - Carla C Oliveira
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, 05508-000 São Paulo, SP, Brazil
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84
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Unique Aspects of rRNA Biogenesis in Trypanosomatids. Trends Parasitol 2019; 35:778-794. [DOI: 10.1016/j.pt.2019.07.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 07/20/2019] [Accepted: 07/26/2019] [Indexed: 12/15/2022]
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85
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Sleiman S, Dragon F. Recent Advances on the Structure and Function of RNA Acetyltransferase Kre33/NAT10. Cells 2019; 8:cells8091035. [PMID: 31491951 PMCID: PMC6770127 DOI: 10.3390/cells8091035] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 08/23/2019] [Accepted: 08/25/2019] [Indexed: 02/07/2023] Open
Abstract
Ribosome biogenesis is one of the most energy demanding processes in the cell. In eukaryotes, the main steps of this process occur in the nucleolus and include pre-ribosomal RNA (pre-rRNA) processing, post-transcriptional modifications, and assembly of many non-ribosomal factors and ribosomal proteins in order to form mature and functional ribosomes. In yeast and humans, the nucleolar RNA acetyltransferase Kre33/NAT10 participates in different maturation events, such as acetylation and processing of 18S rRNA, and assembly of the 40S ribosomal subunit. Here, we review the structural and functional features of Kre33/NAT10 RNA acetyltransferase, and we underscore the importance of this enzyme in ribosome biogenesis, as well as in acetylation of non-ribosomal targets. We also report on the role of human NAT10 in Hutchinson-Gilford progeria syndrome.
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Affiliation(s)
- Sophie Sleiman
- Département des Sciences Biologiques and Centre d'Excellence en Recherche sur les Maladies Orphelines-Fondation Courtois (CERMO-FC), Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada.
| | - Francois Dragon
- Département des Sciences Biologiques and Centre d'Excellence en Recherche sur les Maladies Orphelines-Fondation Courtois (CERMO-FC), Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada.
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86
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Sáez-Vásquez J, Delseny M. Ribosome Biogenesis in Plants: From Functional 45S Ribosomal DNA Organization to Ribosome Assembly Factors. THE PLANT CELL 2019; 31:1945-1967. [PMID: 31239391 PMCID: PMC6751116 DOI: 10.1105/tpc.18.00874] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 05/28/2019] [Accepted: 06/25/2019] [Indexed: 05/11/2023]
Abstract
The transcription of 18S, 5.8S, and 18S rRNA genes (45S rDNA), cotranscriptional processing of pre-rRNA, and assembly of mature rRNA with ribosomal proteins are the linchpins of ribosome biogenesis. In yeast (Saccharomyces cerevisiae) and animal cells, hundreds of pre-rRNA processing factors have been identified and their involvement in ribosome assembly determined. These studies, together with structural analyses, have yielded comprehensive models of the pre-40S and pre-60S ribosome subunits as well as the largest cotranscriptionally assembled preribosome particle: the 90S/small subunit processome. Here, we present the current knowledge of the functional organization of 45S rDNA, pre-rRNA transcription, rRNA processing activities, and ribosome assembly factors in plants, focusing on data from Arabidopsis (Arabidopsis thaliana). Based on yeast and mammalian cell studies, we describe the ribonucleoprotein complexes and RNA-associated activities and discuss how they might specifically affect the production of 40S and 60S subunits. Finally, we review recent findings concerning pre-rRNA processing pathways and a novel mechanism involved in a ribosome stress response in plants.
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Affiliation(s)
- Julio Sáez-Vásquez
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France, and Universite Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France
| | - Michel Delseny
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France, and Universite Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France
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87
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Pillon MC, Lo YH, Stanley RE. IT'S 2 for the price of 1: Multifaceted ITS2 processing machines in RNA and DNA maintenance. DNA Repair (Amst) 2019; 81:102653. [PMID: 31324529 PMCID: PMC6764878 DOI: 10.1016/j.dnarep.2019.102653] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cells utilize sophisticated RNA processing machines to ensure the quality of RNA. Many RNA processing machines have been further implicated in regulating the DNA damage response signifying a strong link between RNA processing and genome maintenance. One of the most intricate and highly regulated RNA processing pathways is the processing of the precursor ribosomal RNA (pre-rRNA), which is paramount for the production of ribosomes. Removal of the Internal Transcribed Spacer 2 (ITS2), located between the 5.8S and 25S rRNA, is one of the most complex steps of ribosome assembly. Processing of the ITS2 is initiated by the newly discovered endoribonuclease Las1, which cleaves at the C2 site within the ITS2, generating products that are further processed by the polynucleotide kinase Grc3, the 5'→3' exonuclease Rat1, and the 3'→5' RNA exosome complex. In addition to their defined roles in ITS2 processing, these critical cellular machines participate in other stages of ribosome assembly, turnover of numerous cellular RNAs, and genome maintenance. Here we summarize recent work defining the molecular mechanisms of ITS2 processing by these essential RNA processing machines and highlight their emerging roles in transcription termination, heterochromatin function, telomere maintenance, and DNA repair.
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Affiliation(s)
- Monica C Pillon
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Yu-Hua Lo
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Robin E Stanley
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA.
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88
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Thermophile 90S Pre-ribosome Structures Reveal the Reverse Order of Co-transcriptional 18S rRNA Subdomain Integration. Mol Cell 2019; 75:1256-1269.e7. [DOI: 10.1016/j.molcel.2019.06.032] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 06/11/2019] [Accepted: 06/21/2019] [Indexed: 11/23/2022]
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89
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Correll CC, Bartek J, Dundr M. The Nucleolus: A Multiphase Condensate Balancing Ribosome Synthesis and Translational Capacity in Health, Aging and Ribosomopathies. Cells 2019; 8:cells8080869. [PMID: 31405125 PMCID: PMC6721831 DOI: 10.3390/cells8080869] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/31/2019] [Accepted: 08/06/2019] [Indexed: 12/21/2022] Open
Abstract
The nucleolus is the largest membrane-less structure in the eukaryotic nucleus. It is involved in the biogenesis of ribosomes, essential macromolecular machines responsible for synthesizing all proteins required by the cell. The assembly of ribosomes is evolutionarily conserved and is the most energy-consuming cellular process needed for cell growth, proliferation, and homeostasis. Despite the significance of this process, the intricate pathophysiological relationship between the nucleolus and protein synthesis has only recently begun to emerge. Here, we provide perspective on new principles governing nucleolar formation and the resulting multiphase organization driven by liquid-liquid phase separation. With recent advances in the structural analysis of ribosome formation, we highlight the current understanding of the step-wise assembly of pre-ribosomal subunits and the quality control required for proper function. Finally, we address how aging affects ribosome genesis and how genetic defects in ribosome formation cause ribosomopathies, complex diseases with a predisposition to cancer.
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Affiliation(s)
- Carl C Correll
- Center for Proteomics and Molecular Therapeutics, Rosalind Franklin University of Medicine & Science, North Chicago, IL 60064, USA.
| | - Jiri Bartek
- Danish Cancer Society Research Center, Genome Integrity Unit, DK-2100 Copenhagen, Denmark
- Division of Genome Biology, Department of Medical Biochemistry and Biophysics, Science for Life Laboratory, Karolinska Institute, SE-171 77 Stockholm, Sweden
| | - Miroslav Dundr
- Center for Cancer Cell Biology Immunology and Infection, Rosalind Franklin University of Medicine & Science, North Chicago, IL 60064, USA.
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90
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Ahmed YL, Thoms M, Mitterer V, Sinning I, Hurt E. Crystal structures of Rea1-MIDAS bound to its ribosome assembly factor ligands resembling integrin-ligand-type complexes. Nat Commun 2019; 10:3050. [PMID: 31296859 PMCID: PMC6624252 DOI: 10.1038/s41467-019-10922-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 06/10/2019] [Indexed: 01/08/2023] Open
Abstract
The Rea1 AAA+-ATPase dislodges assembly factors from pre-60S ribosomes upon ATP hydrolysis, thereby driving ribosome biogenesis. Here, we present crystal structures of Rea1-MIDAS, the conserved domain at the tip of the flexible Rea1 tail, alone and in complex with its substrate ligands, the UBL domains of Rsa4 or Ytm1. These complexes have structural similarity to integrin α-subunit domains when bound to extracellular matrix ligands, which for integrin biology is a key determinant for force-bearing cell-cell adhesion. However, the presence of additional motifs equips Rea1-MIDAS for its tasks in ribosome maturation. One loop insert cofunctions as an NLS and to activate the mechanochemical Rea1 cycle, whereas an additional β-hairpin provides an anchor to hold the ligand UBL domains in place. Our data show the versatility of the MIDAS fold for mechanical force transmission in processes as varied as integrin-mediated cell adhesion and mechanochemical removal of assembly factors from pre-ribosomes.
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Affiliation(s)
| | - Matthias Thoms
- Heidelberg University Biochemistry Center, D-69120, Heidelberg, Germany.,Gene Center, University of Munich, D-81377, Munich, Germany
| | - Valentin Mitterer
- Heidelberg University Biochemistry Center, D-69120, Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center, D-69120, Heidelberg, Germany.
| | - Ed Hurt
- Heidelberg University Biochemistry Center, D-69120, Heidelberg, Germany.
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91
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Awad D, Prattes M, Kofler L, Rössler I, Loibl M, Pertl M, Zisser G, Wolinski H, Pertschy B, Bergler H. Inhibiting eukaryotic ribosome biogenesis. BMC Biol 2019; 17:46. [PMID: 31182083 PMCID: PMC6558755 DOI: 10.1186/s12915-019-0664-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 05/14/2019] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Ribosome biogenesis is a central process in every growing cell. In eukaryotes, it requires more than 250 non-ribosomal assembly factors, most of which are essential. Despite this large repertoire of potential targets, only very few chemical inhibitors of ribosome biogenesis are known so far. Such inhibitors are valuable tools to study this highly dynamic process and elucidate mechanistic details of individual maturation steps. Moreover, ribosome biogenesis is of particular importance for fast proliferating cells, suggesting its inhibition could be a valid strategy for treatment of tumors or infections. RESULTS We systematically screened ~ 1000 substances for inhibitory effects on ribosome biogenesis using a microscopy-based screen scoring ribosomal subunit export defects. We identified 128 compounds inhibiting maturation of either the small or the large ribosomal subunit or both. Northern blot analysis demonstrates that these inhibitors cause a broad spectrum of different rRNA processing defects. CONCLUSIONS Our findings show that the individual inhibitors affect a wide range of different maturation steps within the ribosome biogenesis pathway. Our results provide for the first time a comprehensive set of inhibitors to study ribosome biogenesis by chemical inhibition of individual maturation steps and establish the process as promising druggable pathway for chemical intervention.
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Affiliation(s)
- Dominik Awad
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/EG, A-8010, Graz, Austria
- Present address: Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Michael Prattes
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/EG, A-8010, Graz, Austria
| | - Lisa Kofler
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/EG, A-8010, Graz, Austria
| | - Ingrid Rössler
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/EG, A-8010, Graz, Austria
| | - Mathias Loibl
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/EG, A-8010, Graz, Austria
| | - Melanie Pertl
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/EG, A-8010, Graz, Austria
| | - Gertrude Zisser
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/EG, A-8010, Graz, Austria
| | - Heimo Wolinski
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/EG, A-8010, Graz, Austria
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/EG, A-8010, Graz, Austria.
| | - Helmut Bergler
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/EG, A-8010, Graz, Austria.
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92
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Kargas V, Castro-Hartmann P, Escudero-Urquijo N, Dent K, Hilcenko C, Sailer C, Zisser G, Marques-Carvalho MJ, Pellegrino S, Wawiórka L, Freund SMV, Wagstaff JL, Andreeva A, Faille A, Chen E, Stengel F, Bergler H, Warren AJ. Mechanism of completion of peptidyltransferase centre assembly in eukaryotes. eLife 2019; 8:e44904. [PMID: 31115337 PMCID: PMC6579518 DOI: 10.7554/elife.44904] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 05/20/2019] [Indexed: 01/05/2023] Open
Abstract
During their final maturation in the cytoplasm, pre-60S ribosomal particles are converted to translation-competent large ribosomal subunits. Here, we present the mechanism of peptidyltransferase centre (PTC) completion that explains how integration of the last ribosomal proteins is coupled to release of the nuclear export adaptor Nmd3. Single-particle cryo-EM reveals that eL40 recruitment stabilises helix 89 to form the uL16 binding site. The loading of uL16 unhooks helix 38 from Nmd3 to adopt its mature conformation. In turn, partial retraction of the L1 stalk is coupled to a conformational switch in Nmd3 that allows the uL16 P-site loop to fully accommodate into the PTC where it competes with Nmd3 for an overlapping binding site (base A2971). Our data reveal how the central functional site of the ribosome is sculpted and suggest how the formation of translation-competent 60S subunits is disrupted in leukaemia-associated ribosomopathies.
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Affiliation(s)
- Vasileios Kargas
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Pablo Castro-Hartmann
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Norberto Escudero-Urquijo
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Kyle Dent
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Christine Hilcenko
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Carolin Sailer
- Department of BiologyUniversity of KonstanzKonstanzGermany
| | - Gertrude Zisser
- Institute of Molecular BiosciencesUniversity of GrazGrazAustria
| | - Maria J Marques-Carvalho
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Simone Pellegrino
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Leszek Wawiórka
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
- Department of Molecular BiologyMaria Curie-Skłodowska UniversityLublinPoland
| | | | | | | | - Alexandre Faille
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Edwin Chen
- Faculty of Biological SciencesUniversity of LeedsLeedsUnited Kingdom
| | | | - Helmut Bergler
- Institute of Molecular BiosciencesUniversity of GrazGrazAustria
| | - Alan John Warren
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
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93
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Ferretti MB, Karbstein K. Does functional specialization of ribosomes really exist? RNA (NEW YORK, N.Y.) 2019; 25:521-538. [PMID: 30733326 PMCID: PMC6467006 DOI: 10.1261/rna.069823.118] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
It has recently become clear that ribosomes are much more heterogeneous than previously thought, with diversity arising from rRNA sequence and modifications, ribosomal protein (RP) content and posttranslational modifications (PTMs), as well as bound nonribosomal proteins. In some cases, the existence of these diverse ribosome populations has been verified by biochemical or structural methods. Furthermore, knockout or knockdown of RPs can diversify ribosome populations, while also affecting the translation of some mRNAs (but not others) with biological consequences. However, the effects on translation arising from depletion of diverse proteins can be highly similar, suggesting that there may be a more general defect in ribosome function or stability, perhaps arising from reduced ribosome numbers. Consistently, overall reduced ribosome numbers can differentially affect subclasses of mRNAs, necessitating controls for specificity. Moreover, in order to study the functional consequences of ribosome diversity, perturbations including affinity tags and knockouts are introduced, which can also affect the outcome of the experiment. Here we review the available literature to carefully evaluate whether the published data support functional diversification, defined as diverse ribosome populations differentially affecting translation of distinct mRNA (classes). Based on these observations and the commonly observed cellular responses to perturbations in the system, we suggest a set of important controls to validate functional diversity, which should include gain-of-function assays and the demonstration of inducibility under physiological conditions.
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Affiliation(s)
- Max B Ferretti
- Department of Integrative Structural and Molecular Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA
- The Skaggs Graduate School of Chemical and Biological Sciences, The Scripps Research Institute, Jupiter, Florida 33458, USA
| | - Katrin Karbstein
- Department of Integrative Structural and Molecular Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA
- The Skaggs Graduate School of Chemical and Biological Sciences, The Scripps Research Institute, Jupiter, Florida 33458, USA
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94
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Chaker-Margot M, Klinge S. Assembly and early maturation of large subunit precursors. RNA (NEW YORK, N.Y.) 2019; 25:465-471. [PMID: 30670483 PMCID: PMC6426289 DOI: 10.1261/rna.069799.118] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 01/19/2019] [Indexed: 06/09/2023]
Abstract
The eukaryotic ribosome is assembled through a complex process involving more than 200 factors. As preribosomal RNA is transcribed, assembly factors bind the nascent pre-rRNA and guide its correct folding, modification, and cleavage. While these early events in the assembly of the small ribosomal subunit have been relatively well characterized, assembly of the large subunit precursors, or pre-60S, is less well understood. Recent structures of nucleolar intermediates of large subunit assembly have shed light on the role of many early large subunit assembly factors, but how these particles emerge is still unknown. Here, we use the expression and purification of truncated pre-rRNAs to examine the initial assembly of pre-60S particles. Using this approach, we can recapitulate the early recruitment of large subunit assembly factors mainly to the domains I, II, and VI of the assembling 25S rRNA.
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MESH Headings
- Aptamers, Nucleotide/chemical synthesis
- Aptamers, Nucleotide/metabolism
- Cloning, Molecular
- Organelle Biogenesis
- Plasmids/chemistry
- Plasmids/metabolism
- RNA Precursors/genetics
- RNA Precursors/metabolism
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- Ribosomal Proteins/genetics
- Ribosomal Proteins/metabolism
- Ribosome Subunits, Large, Eukaryotic/genetics
- Ribosome Subunits, Large, Eukaryotic/metabolism
- Ribosome Subunits, Large, Eukaryotic/ultrastructure
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Staining and Labeling/methods
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Affiliation(s)
- Malik Chaker-Margot
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, New York 10065, USA
- Tri-Institutional Training Program in Chemical Biology, The Rockefeller University, New York, New York 10065, USA
| | - Sebastian Klinge
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, New York 10065, USA
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95
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Chikne V, Shanmugha Rajan K, Shalev-Benami M, Decker K, Cohen-Chalamish S, Madmoni H, Biswas VK, Kumar Gupta S, Doniger T, Unger R, Tschudi C, Ullu E, Michaeli S. Small nucleolar RNAs controlling rRNA processing in Trypanosoma brucei. Nucleic Acids Res 2019; 47:2609-2629. [PMID: 30605535 PMCID: PMC6411936 DOI: 10.1093/nar/gky1287] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 12/04/2018] [Accepted: 12/20/2018] [Indexed: 12/19/2022] Open
Abstract
In trypanosomes, in contrast to most eukaryotes, the large subunit (LSU) ribosomal RNA is fragmented into two large and four small ribosomal RNAs (srRNAs) pieces, and this additional processing likely requires trypanosome-specific factors. Here, we examined the role of 10 abundant small nucleolar RNAs (snoRNAs) involved in rRNA processing. We show that each snoRNA involved in LSU processing associates with factors engaged in either early or late biogenesis steps. Five of these snoRNAs interact with the intervening sequences of rRNA precursor, whereas the others only guide rRNA modifications. The function of the snoRNAs was explored by silencing snoRNAs. The data suggest that the LSU rRNA processing events do not correspond to the order of rRNA transcription, and that srRNAs 2, 4 and 6 which are part of LSU are processed before srRNA1. Interestingly, the 6 snoRNAs that affect srRNA1 processing guide modifications on rRNA positions that span locations from the protein exit tunnel to the srRNA1, suggesting that these modifications may serve as check-points preceding the liberation of srRNA1. This study identifies the highest number of snoRNAs so far described that are involved in rRNA processing and/or rRNA folding and highlights their function in the unique trypanosome rRNA maturation events.
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Affiliation(s)
- Vaibhav Chikne
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 52900 Israel
| | - K Shanmugha Rajan
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 52900 Israel
| | - Moran Shalev-Benami
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Kathryn Decker
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 52900 Israel
| | - Smadar Cohen-Chalamish
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 52900 Israel
| | - Hava Madmoni
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 52900 Israel
| | - Viplov K Biswas
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 52900 Israel
| | - Sachin Kumar Gupta
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 52900 Israel
| | - Tirza Doniger
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 52900 Israel
| | - Ron Unger
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 52900 Israel
| | - Christian Tschudi
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06536, USA
| | - Elisabetta Ullu
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06536, USA
| | - Shulamit Michaeli
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 52900 Israel
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96
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Zhou Y, Musalgaonkar S, Johnson AW, Taylor DW. Tightly-orchestrated rearrangements govern catalytic center assembly of the ribosome. Nat Commun 2019; 10:958. [PMID: 30814529 PMCID: PMC6393466 DOI: 10.1038/s41467-019-08880-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/01/2019] [Indexed: 11/24/2022] Open
Abstract
The catalytic activity of the ribosome is mediated by RNA, yet proteins are essential for the function of the peptidyl transferase center (PTC). In eukaryotes, final assembly of the PTC occurs in the cytoplasm by insertion of the ribosomal protein Rpl10 (uL16). We determine structures of six intermediates in late nuclear and cytoplasmic maturation of the large subunit that reveal a tightly-choreographed sequence of protein and RNA rearrangements controlling the insertion of Rpl10. We also determine the structure of the biogenesis factor Yvh1 and show how it promotes assembly of the P stalk, a critical element for recruitment of GTPases that drive translation. Together, our structures provide a blueprint for final assembly of a functional ribosome. In eukaryotes, ribosome biogenesis culminates in the cytoplasm with the maturation of the peptidyl transfer center (PTC). Here the authors describe several structures of intermediates in late nuclear and cytoplasmic maturation of the large ribosomal subunit that reveal the tightly-choreographed sequence of protein and RNA rearrangements that lead to the completion of the PTC.
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Affiliation(s)
- Yi Zhou
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | | | - Arlen W Johnson
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA. .,Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, 78712, USA.
| | - David W Taylor
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA.,Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, 78712, USA.,Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, 78712, USA.,LIVESTRONG Cancer Institutes, Dell Medical School, Austin, TX, 78712, USA
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97
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Abstract
Ribosomes, which synthesize the proteins of a cell, comprise ribosomal RNA and ribosomal proteins, which coassemble hierarchically during a process termed ribosome biogenesis. Historically, biochemical and molecular biology approaches have revealed how preribosomal particles form and mature in consecutive steps, starting in the nucleolus and terminating after nuclear export into the cytoplasm. However, only recently, due to the revolution in cryo-electron microscopy, could pseudoatomic structures of different preribosomal particles be obtained. Together with in vitro maturation assays, these findings shed light on how nascent ribosomes progress stepwise along a dynamic biogenesis pathway. Preribosomes assemble gradually, chaperoned by a myriad of assembly factors and small nucleolar RNAs, before they reach maturity and enter translation. This information will lead to a better understanding of how ribosome synthesis is linked to other cellular pathways in humans and how it can cause diseases, including cancer, if disturbed.
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Affiliation(s)
- Jochen Baßler
- Biochemistry Center, University of Heidelberg, 69120 Heidelberg, Germany; ,
| | - Ed Hurt
- Biochemistry Center, University of Heidelberg, 69120 Heidelberg, Germany; ,
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98
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RNA helicases mediate structural transitions and compositional changes in pre-ribosomal complexes. Nat Commun 2018; 9:5383. [PMID: 30568249 PMCID: PMC6300602 DOI: 10.1038/s41467-018-07783-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 11/28/2018] [Indexed: 01/31/2023] Open
Abstract
Production of eukaryotic ribosomal subunits is a highly dynamic process; pre-ribosomes undergo numerous structural rearrangements that establish the architecture present in mature complexes and serve as key checkpoints, ensuring the fidelity of ribosome assembly. Using in vivo crosslinking, we here identify the pre-ribosomal binding sites of three RNA helicases. Our data support roles for Has1 in triggering release of the U14 snoRNP, a critical event during early 40S maturation, and in driving assembly of domain I of pre-60S complexes. Binding of Mak5 to domain II of pre-60S complexes promotes recruitment of the ribosomal protein Rpl10, which is necessary for subunit joining and ribosome function. Spb4 binds to a molecular hinge at the base of ES27 facilitating binding of the export factor Arx1, thereby promoting pre-60S export competence. Our data provide important insights into the driving forces behind key structural remodelling events during ribosomal subunit assembly.
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99
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Collins JC, Ghalei H, Doherty JR, Huang H, Culver RN, Karbstein K. Ribosome biogenesis factor Ltv1 chaperones the assembly of the small subunit head. J Cell Biol 2018; 217:4141-4154. [PMID: 30348748 PMCID: PMC6279377 DOI: 10.1083/jcb.201804163] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/17/2018] [Accepted: 09/20/2018] [Indexed: 11/22/2022] Open
Abstract
Collins et al. use yeast genetics, biochemistry, and structure probing to dissect the role of the assembly factor Ltv1 in 40S ribosome maturation. Ribosomes from Ltv1-deficient cells have substoichiometric amounts of Rps10 and Asc1 and misfolded head rRNA, leading to defects in translational fidelity and ribosome-mediated RNA quality control, demonstrating a role for Ltv1 in chaperoning the assembly of the subunit head. The correct assembly of ribosomes from ribosomal RNAs (rRNAs) and ribosomal proteins (RPs) is critical, as indicated by the diseases caused by RP haploinsufficiency and loss of RP stoichiometry in cancer cells. Nevertheless, how assembly of each RP is ensured remains poorly understood. We use yeast genetics, biochemistry, and structure probing to show that the assembly factor Ltv1 facilitates the incorporation of Rps3, Rps10, and Asc1/RACK1 into the small ribosomal subunit head. Ribosomes from Ltv1-deficient yeast have substoichiometric amounts of Rps10 and Asc1 and show defects in translational fidelity and ribosome-mediated RNA quality control. These defects provide a growth advantage under some conditions but sensitize the cells to oxidative stress. Intriguingly, relative to glioma cell lines, breast cancer cells have reduced levels of LTV1 and produce ribosomes lacking RPS3, RPS10, and RACK1. These data describe a mechanism to ensure RP assembly and demonstrate how cancer cells circumvent this mechanism to generate diverse ribosome populations that can promote survival under stress.
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Affiliation(s)
- Jason C Collins
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL
| | - Homa Ghalei
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL
| | - Joanne R Doherty
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL
| | - Haina Huang
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL
| | - Rebecca N Culver
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL
| | - Katrin Karbstein
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL
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100
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Thoms M, Mitterer V, Kater L, Falquet L, Beckmann R, Kressler D, Hurt E. Suppressor mutations in Rpf2-Rrs1 or Rpl5 bypass the Cgr1 function for pre-ribosomal 5S RNP-rotation. Nat Commun 2018; 9:4094. [PMID: 30291245 PMCID: PMC6173701 DOI: 10.1038/s41467-018-06660-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 09/17/2018] [Indexed: 12/03/2022] Open
Abstract
During eukaryotic 60S biogenesis, the 5S RNP requires a large rotational movement to achieve its mature position. Cryo-EM of the Rix1-Rea1 pre-60S particle has revealed the post-rotation stage, in which a gently undulating α-helix corresponding to Cgr1 becomes wedged between Rsa4 and the relocated 5S RNP, but the purpose of this insertion was unknown. Here, we show that cgr1 deletion in yeast causes a slow-growth phenotype and reversion of the pre-60S particle to the pre-rotation stage. However, spontaneous extragenic suppressors could be isolated, which restore growth and pre-60S biogenesis in the absence of Cgr1. Whole-genome sequencing reveals that the suppressor mutations map in the Rpf2–Rrs1 module and Rpl5, which together stabilize the unrotated stage of the 5S RNP. Thus, mutations in factors stabilizing the pre-rotation stage facilitate 5S RNP relocation upon deletion of Cgr1, but Cgr1 itself could stabilize the post-rotation stage. During biogenesis of the eukaryotic 60S ribosome, a large rotational movement of the 5S RNP is required to achieve its mature position. By analyzing extragenic suppressors of crg1—a key factor required for rotation—the authors provide mechanistic insight into a key step of ribosome biogenesis.
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Affiliation(s)
- Matthias Thoms
- Biochemistry Centre, University of Heidelberg, Heidelberg, 69120, Germany.
| | - Valentin Mitterer
- Biochemistry Centre, University of Heidelberg, Heidelberg, 69120, Germany
| | - Lukas Kater
- Gene Center, University of Munich, Munich, 81377, Germany
| | - Laurent Falquet
- University of Fribourg and Swiss Institute of Bioinformatics, Fribourg, 1700, Switzerland
| | | | - Dieter Kressler
- University of Fribourg and Swiss Institute of Bioinformatics, Fribourg, 1700, Switzerland
| | - Ed Hurt
- Biochemistry Centre, University of Heidelberg, Heidelberg, 69120, Germany.
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