1
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Open Issues for Protein Function Assignment in Haloferax volcanii and Other Halophilic Archaea. Genes (Basel) 2021; 12:genes12070963. [PMID: 34202810 PMCID: PMC8305020 DOI: 10.3390/genes12070963] [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: 05/16/2021] [Revised: 06/10/2021] [Accepted: 06/15/2021] [Indexed: 12/14/2022] Open
Abstract
Background: Annotation ambiguities and annotation errors are a general challenge in genomics. While a reliable protein function assignment can be obtained by experimental characterization, this is expensive and time-consuming, and the number of such Gold Standard Proteins (GSP) with experimental support remains very low compared to proteins annotated by sequence homology, usually through automated pipelines. Even a GSP may give a misleading assignment when used as a reference: the homolog may be close enough to support isofunctionality, but the substrate of the GSP is absent from the species being annotated. In such cases, the enzymes cannot be isofunctional. Here, we examined a variety of such issues in halophilic archaea (class Halobacteria), with a strong focus on the model haloarchaeon Haloferax volcanii. Results: Annotated proteins of Hfx. volcanii were identified for which public databases tend to assign a function that is probably incorrect. In some cases, an alternative, probably correct, function can be predicted or inferred from the available evidence, but this has not been adopted by public databases because experimental validation is lacking. In other cases, a probably invalid specific function is predicted by homology, and while there is evidence that this assigned function is unlikely, the true function remains elusive. We listed 50 of those cases, each with detailed background information, so that a conclusion about the most likely biological function can be drawn. For reasons of brevity and comprehension, only the key aspects are listed in the main text, with detailed information being provided in a corresponding section of the Supplementary Materials. Conclusions: Compiling, describing and summarizing these open annotation issues and functional predictions will benefit the scientific community in the general effort to improve the evaluation of protein function assignments and more thoroughly detail them. By highlighting the gaps and likely annotation errors currently in the databases, we hope this study will provide a framework for experimentalists to systematically confirm (or disprove) our function predictions or to uncover yet more unexpected functions.
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2
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YbeY, éminence grise of ribosome biogenesis. Biochem Soc Trans 2021; 49:727-745. [PMID: 33929506 DOI: 10.1042/bst20200669] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 12/30/2022]
Abstract
YbeY is an ultraconserved small protein belonging to the unique heritage shared by most existing bacteria and eukaryotic organelles of bacterial origin, mitochondria and chloroplasts. Studied in more than a dozen of evolutionarily distant species, YbeY is invariably critical for cellular physiology. However, the exact mechanisms by which it exerts such penetrating influence are not completely understood. In this review, we attempt a transversal analysis of the current knowledge about YbeY, based on genetic, structural, and biochemical data from a wide variety of models. We propose that YbeY, in association with the ribosomal protein uS11 and the assembly GTPase Era, plays a critical role in the biogenesis of the small ribosomal subunit, and more specifically its platform region, in diverse genetic systems of bacterial type.
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3
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Knüppel R, Trahan C, Kern M, Wagner A, Grünberger F, Hausner W, Quax TEF, Albers SV, Oeffinger M, Ferreira-Cerca S. Insights into synthesis and function of KsgA/Dim1-dependent rRNA modifications in archaea. Nucleic Acids Res 2021; 49:1662-1687. [PMID: 33434266 PMCID: PMC7897474 DOI: 10.1093/nar/gkaa1268] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/01/2020] [Accepted: 12/21/2020] [Indexed: 12/19/2022] Open
Abstract
Ribosomes are intricate molecular machines ensuring proper protein synthesis in every cell. Ribosome biogenesis is a complex process which has been intensively analyzed in bacteria and eukaryotes. In contrast, our understanding of the in vivo archaeal ribosome biogenesis pathway remains less characterized. Here, we have analyzed the in vivo role of the almost universally conserved ribosomal RNA dimethyltransferase KsgA/Dim1 homolog in archaea. Our study reveals that KsgA/Dim1-dependent 16S rRNA dimethylation is dispensable for the cellular growth of phylogenetically distant archaea. However, proteomics and functional analyses suggest that archaeal KsgA/Dim1 and its rRNA modification activity (i) influence the expression of a subset of proteins and (ii) contribute to archaeal cellular fitness and adaptation. In addition, our study reveals an unexpected KsgA/Dim1-dependent variability of rRNA modifications within the archaeal phylum. Combining structure-based functional studies across evolutionary divergent organisms, we provide evidence on how rRNA structure sequence variability (re-)shapes the KsgA/Dim1-dependent rRNA modification status. Finally, our results suggest an uncoupling between the KsgA/Dim1-dependent rRNA modification completion and its release from the nascent small ribosomal subunit. Collectively, our study provides additional understandings into principles of molecular functional adaptation, and further evolutionary and mechanistic insights into an almost universally conserved step of ribosome synthesis.
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Affiliation(s)
- Robert Knüppel
- Regensburg Center for Biochemistry, Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Christian Trahan
- Institut de Recherches Cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, Québec H2W 1R7, Canada
- Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec H3A 1A3, Canada
- Département de Biochimie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Michael Kern
- Regensburg Center for Biochemistry, Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Alexander Wagner
- Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, Microbiology, University of Freiburg, Freiburg, Germany
| | - Felix Grünberger
- Chair of Microbiology – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Winfried Hausner
- Chair of Microbiology – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Tessa E F Quax
- Archaeal Virus-Host Interactions, Institute of Biology II, Faculty of Biology, Microbiology, University of Freiburg, Freiburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, Microbiology, University of Freiburg, Freiburg, Germany
| | - Marlene Oeffinger
- Institut de Recherches Cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, Québec H2W 1R7, Canada
- Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec H3A 1A3, Canada
- Département de Biochimie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Sébastien Ferreira-Cerca
- Regensburg Center for Biochemistry, Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
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4
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Rai J, Parker MD, Huang H, Choy S, Ghalei H, Johnson MC, Karbstein K, Stroupe ME. An open interface in the pre-80S ribosome coordinated by ribosome assembly factors Tsr1 and Dim1 enables temporal regulation of Fap7. RNA (NEW YORK, N.Y.) 2021; 27:221-233. [PMID: 33219089 PMCID: PMC7812869 DOI: 10.1261/rna.077610.120] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/17/2020] [Indexed: 06/11/2023]
Abstract
During their maturation, nascent 40S subunits enter a translation-like quality control cycle, where they are joined by mature 60S subunits to form 80S-like ribosomes. While these assembly intermediates are essential for maturation and quality control, how they form, and how their structure promotes quality control, remains unknown. To address these questions, we determined the structure of an 80S-like ribosome assembly intermediate to an overall resolution of 3.4 Å. The structure, validated by biochemical data, resolves a large body of previously paradoxical data and illustrates how assembly and translation factors cooperate to promote the formation of an interface that lacks many mature subunit contacts but is stabilized by the universally conserved methyltransferase Dim1. We also show how Tsr1 enables this interface by blocking the canonical binding of eIF5B to 40S subunits, while maintaining its binding to 60S. The structure also shows how this interface leads to unfolding of the platform, which allows for temporal regulation of the ATPase Fap7, thus linking 40S maturation to quality control during ribosome assembly.
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MESH Headings
- Adenylate Kinase/chemistry
- Adenylate Kinase/genetics
- Adenylate Kinase/metabolism
- Binding Sites
- Gene Expression Regulation, Fungal
- Methyltransferases/chemistry
- Methyltransferases/genetics
- Methyltransferases/metabolism
- Models, Molecular
- Nuclear Proteins/chemistry
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Nucleoside-Triphosphatase/chemistry
- Nucleoside-Triphosphatase/genetics
- Nucleoside-Triphosphatase/metabolism
- Organelle Biogenesis
- Protein Binding
- Protein Biosynthesis
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Interaction Domains and Motifs
- Ribosomal Proteins/chemistry
- Ribosomal Proteins/genetics
- Ribosomal Proteins/metabolism
- Ribosome Subunits, Large, Eukaryotic/genetics
- Ribosome Subunits, Large, Eukaryotic/metabolism
- Ribosome Subunits, Large, Eukaryotic/ultrastructure
- Ribosome Subunits, Small, Eukaryotic/genetics
- Ribosome Subunits, Small, Eukaryotic/metabolism
- Ribosome Subunits, Small, Eukaryotic/ultrastructure
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Saccharomyces cerevisiae Proteins/chemistry
- Saccharomyces cerevisiae Proteins/genetics
- Saccharomyces cerevisiae Proteins/metabolism
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Affiliation(s)
- Jay Rai
- Department of Biological Science and the Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, USA
| | - Melissa D Parker
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA
| | - Haina Huang
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA
| | - Stefan Choy
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA
| | - Homa Ghalei
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA
| | - Matthew C Johnson
- Department of Biological Science and the Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, USA
| | - Katrin Karbstein
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA
- HHMI Faculty Scholar, Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, USA
| | - M Elizabeth Stroupe
- Department of Biological Science and the Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, USA
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5
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Summer S, Smirnova A, Gabriele A, Toth U, Fasemore AM, Förstner KU, Kuhn L, Chicher J, Hammann P, Mitulović G, Entelis N, Tarassov I, Rossmanith W, Smirnov A. YBEY is an essential biogenesis factor for mitochondrial ribosomes. Nucleic Acids Res 2020; 48:9762-9786. [PMID: 32182356 PMCID: PMC7515705 DOI: 10.1093/nar/gkaa148] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/24/2020] [Accepted: 02/26/2020] [Indexed: 12/11/2022] Open
Abstract
Ribosome biogenesis requires numerous trans-acting factors, some of which are deeply conserved. In Bacteria, the endoribonuclease YbeY is believed to be involved in 16S rRNA 3′-end processing and its loss was associated with ribosomal abnormalities. In Eukarya, YBEY appears to generally localize to mitochondria (or chloroplasts). Here we show that the deletion of human YBEY results in a severe respiratory deficiency and morphologically abnormal mitochondria as an apparent consequence of impaired mitochondrial translation. Reduced stability of 12S rRNA and the deficiency of several proteins of the small ribosomal subunit in YBEY knockout cells pointed towards a defect in mitochondrial ribosome biogenesis. The specific interaction of mitoribosomal protein uS11m with YBEY suggests that the latter helps to properly incorporate uS11m into the nascent small subunit in its late assembly stage. This scenario shows similarities with final stages of cytosolic ribosome biogenesis, and may represent a late checkpoint before the mitoribosome engages in translation.
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Affiliation(s)
- Sabrina Summer
- Center for Anatomy & Cell Biology, Medical University of Vienna, Vienna A-1090, Austria
| | - Anna Smirnova
- UMR7156 - Molecular Genetics, Genomics, Microbiology, University of Strasbourg, CNRS, Strasbourg F-67000, France
| | - Alessandro Gabriele
- UMR7156 - Molecular Genetics, Genomics, Microbiology, University of Strasbourg, CNRS, Strasbourg F-67000, France
| | - Ursula Toth
- Center for Anatomy & Cell Biology, Medical University of Vienna, Vienna A-1090, Austria
| | | | - Konrad U Förstner
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg 97080, Germany.,TH Köln - University of Applied Sciences, Faculty of Information Science and Communication Studies, Institute of Information Science, Cologne D-50678, Germany.,ZB MED - Information Centre for Life Sciences, Cologne D-50931, Germany
| | - Lauriane Kuhn
- Proteomics Platform Strasbourg-Esplanade, FRC1589, IBMC, CNRS, Strasbourg F-67000, France
| | - Johana Chicher
- Proteomics Platform Strasbourg-Esplanade, FRC1589, IBMC, CNRS, Strasbourg F-67000, France
| | - Philippe Hammann
- Proteomics Platform Strasbourg-Esplanade, FRC1589, IBMC, CNRS, Strasbourg F-67000, France
| | - Goran Mitulović
- Proteomics Core Facility, Clinical Department for Laboratory Medicine, Medical University of Vienna, Vienna A-1090, Austria
| | - Nina Entelis
- UMR7156 - Molecular Genetics, Genomics, Microbiology, University of Strasbourg, CNRS, Strasbourg F-67000, France
| | - Ivan Tarassov
- UMR7156 - Molecular Genetics, Genomics, Microbiology, University of Strasbourg, CNRS, Strasbourg F-67000, France
| | - Walter Rossmanith
- Center for Anatomy & Cell Biology, Medical University of Vienna, Vienna A-1090, Austria
| | - Alexandre Smirnov
- UMR7156 - Molecular Genetics, Genomics, Microbiology, University of Strasbourg, CNRS, Strasbourg F-67000, France
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6
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Li L, Zhu XM, Shi HB, Feng XX, Liu XH, Lin FC. MoFap7, a ribosome assembly factor, is required for fungal development and plant colonization of Magnaporthe oryzae. Virulence 2020; 10:1047-1063. [PMID: 31814506 PMCID: PMC6930019 DOI: 10.1080/21505594.2019.1697123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Fap7, an important ribosome assembly factor, plays a vital role in pre-40S small ribosomal subunit synthesis in Saccharomyces cerevisiae via its ATPase activity. Currently, the biological functions of its homologs in filamentous fungi remain elusive. Here, MoFap7, a homologous protein of ScFap7, was identified in the rice blast fungus Magnaporthe oryzae, which is a devastating fungal pathogen in rice and threatens food security worldwide. ΔMofap7 mutants exhibited defects in growth and development, conidial morphology, appressorium formation and infection, and were sensitive to oxidative stress. In addition, site-directed mutagenesis analysis confirmed that the conserved Walker A motif and Walker B motif in MoFap7 are essential for the biological functions of M. oryzae. We further analyzed the regulation mechanism of MoFap7 in pathogenicity. MoFap7 was found to interact with MoMst50, a regulator functioning in the MAPK Pmk1 signaling pathway, that participates in modulating plant penetration and cell-to-cell invasion by regulating the phosphorylation of MoPmk1. Moreover, MoFap7 interacted with the GTPases MoCdc42 and MoRac1 to control growth and conidiogenesis. Taken together, the results of this study provide novel insights into MoFap7-mediated orchestration of the development and pathogenesis of filamentous fungi.
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Affiliation(s)
- Lin Li
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, China
| | - Xue-Ming Zhu
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, China
| | - Huan-Bin Shi
- State Key Laboratory for Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Xiao-Xiao Feng
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, China
| | - Xiao-Hong Liu
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, China
| | - Fu-Cheng Lin
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, China
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7
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Martín-Villanueva S, Fernández-Fernández J, Rodríguez-Galán O, Fernández-Boraita J, Villalobo E, de La Cruz J. Role of the 40S beak ribosomal protein eS12 in ribosome biogenesis and function in Saccharomyces cerevisiae. RNA Biol 2020; 17:1261-1276. [PMID: 32408794 DOI: 10.1080/15476286.2020.1767951] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
In eukaryotes, the beak structure of 40S subunits is formed by the protrusion of the 18S rRNA helix 33 and three ribosomal proteins: eS10, eS12 and eS31. The exact role of these proteins in ribosome biogenesis is not well understood. While eS10 is an essential protein encoded by two paralogous genes in Saccharomyces cerevisiae, eS12 and eS31 are not essential proteins encoded by the single-copy genes RPS12 and UBI3, respectively. Here, we have analysed the contribution of yeast eS12 to ribosome biogenesis and compared it with that of eS31. Polysome analysis reveals that deletion of either RPS12 or UBI3 results in equivalent 40S deficits. Analysis of pre-rRNA processing indicates that eS12, akin to eS31, is required for efficient processing of 20S pre-rRNA to mature 18S rRNA. Moreover, we show that the 20S pre-rRNA accumulates within cytoplasmic pre-40S particles, as deduced from FISH experiments and the lack of nuclear retention of 40S subunit reporter proteins, in rps12∆ and ubi3∆ cells. However, these particles containing 20S pre-rRNA are not efficiently incorporated into polyribosomes. We also provide evidence for a genetic interaction between eS12 or eS31 and the late-acting 40S assembly factors Enp1 and Ltv1, which appears not to be linked to the dynamics of their association with or release from pre-40S particles in the absence of either eS12 or eS31. Finally, we show that eS12- and eS31-deficient ribosomes exhibit increased levels of translational misreading. Altogether, our data highlight distinct important roles of the beak region during ribosome assembly and function.
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Affiliation(s)
- Sara Martín-Villanueva
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla , Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla , Seville, Spain
| | - José Fernández-Fernández
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla , Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla , Seville, Spain
| | - Olga Rodríguez-Galán
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla , Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla , Seville, Spain
| | - Julia Fernández-Boraita
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla , Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla , Seville, Spain
| | - Eduardo Villalobo
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla , Seville, Spain.,Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla , Seville, Spain
| | - Jesús de La Cruz
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla , Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla , Seville, Spain
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8
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Slovak R, Setzer C, Roiuk M, Bertels J, Göschl C, Jandrasits K, Beemster GTS, Busch W. Ribosome assembly factor Adenylate Kinase 6 maintains cell proliferation and cell size homeostasis during root growth. THE NEW PHYTOLOGIST 2020; 225:2064-2076. [PMID: 31665812 PMCID: PMC7028144 DOI: 10.1111/nph.16291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 10/19/2019] [Indexed: 05/06/2023]
Abstract
From the cellular perspective, organ growth is determined by production and growth of cells. Uncovering how these two processes are coordinated is essential for understanding organogenesis and regulation of organ growth. We utilized phenotypic and genetic variation of 252 natural accessions of Arabidopsis thaliana to conduct genome-wide association studies (GWAS) for identifying genes underlying root growth variation; using a T-DNA line candidate approach, we identified one gene involved in root growth control and characterized its function using microscopy, root growth kinematics, G2/M phase cell count, ploidy levels and ribosome polysome profiles. We identified a factor contributing to root growth control: Arabidopsis Adenylate Kinase 6 (AAK6). AAK6 is required for normal cell production and normal cell elongation, and its natural genetic variation is involved in determining root growth differences between Arabidopsis accessions. A lack of AAK6 reduces cell production in the aak6 root apex, but this is partially compensated for by longer mature root cells. Thereby, aak6 mutants exhibit compensatory cell enlargement, a phenomenon unexpected in roots. Moreover, aak6 plants accumulate 80S ribosomes while the polysome profile remains unchanged, consistent with a phenotype of perturbed ribosome biogenesis. In conclusion, AAK6 impacts ribosome abundance, cell production and thereby root growth.
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Affiliation(s)
- Radka Slovak
- Gregor Mendel Institute (GMI)Austrian Academy of SciencesVienna Biocenter (VBC)Dr Bohr‐Gasse 31030ViennaAustria
- Department of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
| | - Claudia Setzer
- Gregor Mendel Institute (GMI)Austrian Academy of SciencesVienna Biocenter (VBC)Dr Bohr‐Gasse 31030ViennaAustria
| | - Mykola Roiuk
- Max F. Perutz Laboratories (MFPL)Vienna Biocenter (VBC)Dr Bohr‐Gasse 91030ViennaAustria
| | - Jonas Bertels
- Laboratory for Integrated Molecular Plant Physiology Research (IMPRES)Department of BiologyUniversity of AntwerpGroenenborgerlaan 1712020AntwerpenBelgium
| | - Christian Göschl
- Gregor Mendel Institute (GMI)Austrian Academy of SciencesVienna Biocenter (VBC)Dr Bohr‐Gasse 31030ViennaAustria
| | - Katharina Jandrasits
- Gregor Mendel Institute (GMI)Austrian Academy of SciencesVienna Biocenter (VBC)Dr Bohr‐Gasse 31030ViennaAustria
| | - Gerrit T. S. Beemster
- Laboratory for Integrated Molecular Plant Physiology Research (IMPRES)Department of BiologyUniversity of AntwerpGroenenborgerlaan 1712020AntwerpenBelgium
| | - Wolfgang Busch
- Gregor Mendel Institute (GMI)Austrian Academy of SciencesVienna Biocenter (VBC)Dr Bohr‐Gasse 31030ViennaAustria
- Plant Molecular and Cellular Biology LaboratorySalk Institute For Biological Studies10010 N Torrey Pines RdLa JollaCA92037USA
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9
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Jüttner M, Weiß M, Ostheimer N, Reglin C, Kern M, Knüppel R, Ferreira-Cerca S. A versatile cis-acting element reporter system to study the function, maturation and stability of ribosomal RNA mutants in archaea. Nucleic Acids Res 2020; 48:2073-2090. [PMID: 31828323 PMCID: PMC7038931 DOI: 10.1093/nar/gkz1156] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 11/12/2019] [Accepted: 11/30/2019] [Indexed: 12/17/2022] Open
Abstract
General molecular principles of ribosome biogenesis have been well explored in bacteria and eukaryotes. Collectively, these studies have revealed important functional differences and few similarities between these processes. Phylogenetic studies suggest that the information processing machineries from archaea and eukaryotes are evolutionary more closely related than their bacterial counterparts. These observations raise the question of how ribosome synthesis in archaea may proceed in vivo. In this study, we describe a versatile plasmid-based cis-acting reporter system allowing to analyze in vivo the consequences of ribosomal RNA mutations in the model archaeon Haloferax volcanii. Applying this system, we provide evidence that the bulge-helix-bulge motif enclosed within the ribosomal RNA processing stems is required for the formation of archaeal-specific circular-pre-rRNA intermediates and mature rRNAs. In addition, we have collected evidences suggesting functional coordination of the early steps of ribosome synthesis in H. volcanii. Together our investigation describes a versatile platform allowing to generate and functionally analyze the fate of diverse rRNA variants, thereby paving the way to better understand the cis-acting molecular determinants necessary for archaeal ribosome synthesis, maturation, stability and function.
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Affiliation(s)
- Michael Jüttner
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Matthias Weiß
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Nina Ostheimer
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Corinna Reglin
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Michael Kern
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Robert Knüppel
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Sébastien Ferreira-Cerca
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
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10
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Kaiser M, Hacker C, Duchardt-Ferner E, Wöhnert J. 1H, 13C, 15N backbone NMR resonance assignments for the rRNA methyltransferase Dim1 from the hyperthermophilic archaeon Pyrococcus horikoshii. BIOMOLECULAR NMR ASSIGNMENTS 2019; 13:309-314. [PMID: 31069720 DOI: 10.1007/s12104-019-09897-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 05/03/2019] [Indexed: 06/09/2023]
Abstract
The protein dimethyladenosine transferase 1 (Dim1) is a highly conserved protein occurring in organisms ranging from bacteria such as E. coli where it is named KsgA to humans. Since Dim1 is involved in the biogenesis of the small ribosomal subunit it is an essential protein. During ribosome biogenesis Dim1 acts as an rRNA modification enzyme and dimethylates two adjacent adenosine residues of the small ribosomal subunit rRNA. In eukaryotes it is also required to ensure the proper endonucleolytic processing of the small ribosomal subunit rRNA precursor. Recently, a third function was proposed for eukaryotic Dim1. Karbstein and coworkers suggested that Dim1 interacts with the essential ribosome assembly factor Fap7 and that Fap7 is responsible for the dissociation of Dim1 from the nascent small ribosomal subunit. Here, we report the backbone 1H, 13C and 15N NMR resonance assignments for the 30.9 kDa Dim1 homologue from the hyperthermophilic archaeon Pyrococcus horikoshii (PhDim1) as a prerequisite for a detailed structural investigation of the PhDim1/PhFap7 interaction.
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Affiliation(s)
- Marco Kaiser
- Institute for Molecular Biosciences, Goethe University Frankfurt/M, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany.
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt/M, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany.
| | - Carolin Hacker
- Institute for Molecular Biosciences, Goethe University Frankfurt/M, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt/M, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
| | - Elke Duchardt-Ferner
- Institute for Molecular Biosciences, Goethe University Frankfurt/M, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt/M, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
| | - Jens Wöhnert
- Institute for Molecular Biosciences, Goethe University Frankfurt/M, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt/M, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
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11
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Rössler I, Embacher J, Pillet B, Murat G, Liesinger L, Hafner J, Unterluggauer JJ, Birner-Gruenberger R, Kressler D, Pertschy B. Tsr4 and Nap1, two novel members of the ribosomal protein chaperOME. Nucleic Acids Res 2019; 47:6984-7002. [PMID: 31062022 PMCID: PMC6648895 DOI: 10.1093/nar/gkz317] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/15/2019] [Accepted: 04/19/2019] [Indexed: 12/12/2022] Open
Abstract
Dedicated chaperones protect newly synthesized ribosomal proteins (r-proteins) from aggregation and accompany them on their way to assembly into nascent ribosomes. Currently, only nine of the ∼80 eukaryotic r-proteins are known to be guarded by such chaperones. In search of new dedicated r-protein chaperones, we performed a tandem-affinity purification based screen and looked for factors co-enriched with individual small subunit r-proteins. We report the identification of Nap1 and Tsr4 as direct binding partners of Rps6 and Rps2, respectively. Both factors promote the solubility of their r-protein clients in vitro. While Tsr4 is specific for Rps2, Nap1 has several interaction partners including Rps6 and two other r-proteins. Tsr4 binds co-translationally to the essential, eukaryote-specific N-terminal extension of Rps2, whereas Nap1 interacts with a large, mostly eukaryote-specific binding surface of Rps6. Mutation of the essential Tsr4 and deletion of the non-essential Nap1 both enhance the 40S synthesis defects of the corresponding r-protein mutants. Our findings highlight that the acquisition of eukaryote-specific domains in r-proteins was accompanied by the co-evolution of proteins specialized to protect these domains and emphasize the critical role of r-protein chaperones for the synthesis of eukaryotic ribosomes.
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Affiliation(s)
- Ingrid Rössler
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Julia Embacher
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Benjamin Pillet
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Guillaume Murat
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Laura Liesinger
- BioTechMed-Graz, Graz, Austria
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- Omics Center Graz, BioTechMed-Graz, Graz, Austria
| | - Jutta Hafner
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Julia Judith Unterluggauer
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Ruth Birner-Gruenberger
- BioTechMed-Graz, Graz, Austria
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- Omics Center Graz, BioTechMed-Graz, Graz, Austria
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- BioTechMed-Graz, Graz, Austria
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12
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Cerezo E, Plisson-Chastang C, Henras AK, Lebaron S, Gleizes PE, O'Donohue MF, Romeo Y, Henry Y. Maturation of pre-40S particles in yeast and humans. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 10:e1516. [PMID: 30406965 DOI: 10.1002/wrna.1516] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 09/02/2018] [Accepted: 10/01/2018] [Indexed: 12/22/2022]
Abstract
The synthesis of ribosomal subunits in eukaryotes requires the interplay of numerous maturation and assembly factors (AFs) that intervene in the insertion of ribosomal proteins within pre-ribosomal particles, the ribosomal subunit precursors, as well as in pre-ribosomal RNA (rRNA) processing and folding. Here, we review the intricate nuclear and cytoplasmic maturation steps of pre-40S particles, the precursors to the small ribosomal subunits, in both yeast and human cells, with particular emphasis on the timing and mechanisms of AF association with and dissociation from pre-40S particles and the roles of these AFs in the maturation process. We highlight the particularly complex pre-rRNA processing pathway in human cells, compared to yeast, to generate the mature 18S rRNA. We discuss the information gained from the recently published cryo-electron microscopy atomic models of yeast and human pre-40S particles, as well as the checkpoint/quality control systems that seem to operate to probe functional sites within yeast cytoplasmic pre-40S particles. This article is categorized under: RNA Processing > rRNA Processing Translation > Ribosome Biogenesis.
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Affiliation(s)
- Emilie Cerezo
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Célia Plisson-Chastang
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Anthony K Henras
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Simon Lebaron
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Pierre-Emmanuel Gleizes
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Marie-Françoise O'Donohue
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Yves Romeo
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Yves Henry
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
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13
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Schütz S, Michel E, Damberger FF, Oplová M, Peña C, Leitner A, Aebersold R, Allain FHT, Panse VG. Molecular basis for disassembly of an importin:ribosomal protein complex by the escortin Tsr2. Nat Commun 2018; 9:3669. [PMID: 30201955 PMCID: PMC6131548 DOI: 10.1038/s41467-018-06160-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/22/2018] [Indexed: 01/16/2023] Open
Abstract
Disordered extensions at the termini and short internal insertions distinguish eukaryotic ribosomal proteins (r-proteins) from their anucleated archaeal counterparts. Here, we report an NMR structure of such a eukaryotic-specific segment (ESS) in the r-protein eS26 in complex with the escortin Tsr2. The structure reveals how ESS attracts Tsr2 specifically to importin:eS26 complexes entering the nucleus in order to trigger non-canonical RanGTP-independent disassembly. Tsr2 then sequesters the released eS26 and prevents rebinding to the importin, providing an alternative allosteric mechanism to terminate the process of nuclear import. Notably, a Diamond–Blackfan anemia-associated Tsr2 mutant protein is impaired in binding to ESS, unveiling a critical role for this interaction in human hematopoiesis. We propose that eS26-ESS and Tsr2 are components of a nuclear sorting system that co-evolved with the emergence of the nucleocytoplasmic barrier and transport carriers. Ribosomal proteins are transported to the nucleus with the help of importins, from which they are released prior to incorporation into the nascent ribosome. Here the authors report the NMR structure of the ribosomal protein eS26 in complex with the escortin Tsr2 and shed light on the mechanism of eS26 release from importin.
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Affiliation(s)
- Sabina Schütz
- Institute of Medical Microbiology, University of Zurich, 8006, Zurich, Switzerland
| | - Erich Michel
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Fred F Damberger
- Institute of Molecular Biology & Biophysics, ETH Zurich, 8093, Zurich, Switzerland
| | - Michaela Oplová
- Institute of Medical Microbiology, University of Zurich, 8006, Zurich, Switzerland.,Institute of Biochemistry, ETH Zurich, 8093, Zurich, Switzerland
| | - Cohue Peña
- Institute of Medical Microbiology, University of Zurich, 8006, Zurich, Switzerland
| | - Alexander Leitner
- Institute of Molecular Systems Biology, ETH Zurich, 8093, Zurich, Switzerland
| | - Ruedi Aebersold
- Institute of Molecular Systems Biology, ETH Zurich, 8093, Zurich, Switzerland.,Faculty of Science, University of Zurich, Zurich, 8057, Switzerland
| | - Frederic H-T Allain
- Institute of Molecular Biology & Biophysics, ETH Zurich, 8093, Zurich, Switzerland.
| | - Vikram Govind Panse
- Institute of Medical Microbiology, University of Zurich, 8006, Zurich, Switzerland.
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14
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Sturm M, Cheng J, Baßler J, Beckmann R, Hurt E. Interdependent action of KH domain proteins Krr1 and Dim2 drive the 40S platform assembly. Nat Commun 2017; 8:2213. [PMID: 29263326 PMCID: PMC5738357 DOI: 10.1038/s41467-017-02199-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 11/12/2017] [Indexed: 12/14/2022] Open
Abstract
Ribosome biogenesis begins in the nucleolus with the formation of 90S pre-ribosomes, from which pre-40S and pre-60S particles arise that subsequently follow separate maturation pathways. Here, we show how structurally related assembly factors, the KH domain proteins Krr1 and Dim2, participate in ribosome assembly. Initially, Dim2 (Pno1) orchestrates an early step in small subunit biogenesis through its binding to a distinct region of the 90S pre-ribosome. This involves Utp1 of the UTP-B module, and Utp14, an activator of the DEAH-box helicase Dhr1 that catalyzes the removal of U3 snoRNP from the 90S. Following this dismantling reaction, the pre-40S subunit emerges, but Dim2 relocates to the pre-40S platform domain, previously occupied in the 90S by the other KH factor Krr1 through its interaction with Rps14 and the UTP-C module. Our findings show how the structurally related Krr1 and Dim2 can control stepwise ribosome assembly during the 90S-to-pre-40S subunit transition. The biogenesis of eukaryotic ribosomes involves the coordinated interplay of a large number of assembly factors. Here, the authors detail how the conserved KH domain-containing assembly factors Dim2 and Krr1 function in ordering key events during ribosome maturation.
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Affiliation(s)
- Miriam Sturm
- Biochemistry Centre, University of Heidelberg, Heidelberg, 69221, Germany
| | - Jingdong Cheng
- Department of Biochemistry, Gene Center, Center for integrated Protein Science - Munich (CiPS-M), Ludwig-Maximillian University, Munich, 81377, Germany
| | - Jochen Baßler
- Biochemistry Centre, University of Heidelberg, Heidelberg, 69221, Germany
| | - Roland Beckmann
- Department of Biochemistry, Gene Center, Center for integrated Protein Science - Munich (CiPS-M), Ludwig-Maximillian University, Munich, 81377, Germany
| | - Ed Hurt
- Biochemistry Centre, University of Heidelberg, Heidelberg, 69221, Germany.
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15
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Belhabich-Baumas K, Joret C, Jády BE, Plisson-Chastang C, Shayan R, Klopp C, Henras AK, Henry Y, Mougin A. The Rio1p ATPase hinders premature entry into translation of late pre-40S pre-ribosomal particles. Nucleic Acids Res 2017; 45:10824-10836. [PMID: 28977579 PMCID: PMC5737503 DOI: 10.1093/nar/gkx734] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/17/2017] [Indexed: 12/03/2022] Open
Abstract
Cytoplasmic maturation of precursors to the small ribosomal subunit in yeast requires the intervention of a dozen assembly factors (AFs), the precise roles of which remain elusive. One of these is Rio1p that seems to intervene at a late step of pre-40S particle maturation. We have investigated the role played by Rio1p in the dynamic association and dissociation of AFs with and from pre-40S particles. Our results indicate that Rio1p depletion leads to the stalling of at least 4 AFs (Nob1p, Tsr1p, Pno1p/Dim2p and Fap7p) in 80S-like particles. We conclude that Rio1p is important for the timely release of these factors from 80S-like particles. In addition, we present immunoprecipitation and electron microscopy evidence suggesting that when Rio1p is depleted, a subset of Nob1p-containing pre-40S particles associate with translating polysomes. Using Nob1p as bait, we purified pre-40S particles from cells lacking Rio1p and performed ribosome profiling experiments which suggest that immature 40S subunits can carry out translation elongation. We conclude that lack of Rio1p allows premature entry of pre-40S particles in the translation process and that the presence of Nob1p and of the 18S rRNA 3′ extension in the 20S pre-rRNA is not incompatible with translation elongation.
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Affiliation(s)
- Kamila Belhabich-Baumas
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Clément Joret
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Beáta E Jády
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Célia Plisson-Chastang
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Ramtin Shayan
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Christophe Klopp
- Unité de Mathématiques et Informatique Appliquées, INRA, 31320 Castanet Tolosan, France
| | - Anthony K Henras
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Yves Henry
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Annie Mougin
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
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16
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17
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Madru C, Leulliot N, Lebaron S. [Ribosomes synthesis at the heart of cell proliferation]. Med Sci (Paris) 2017; 33:613-619. [PMID: 28990563 DOI: 10.1051/medsci/20173306018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Ribosomes are central to gene expression. Their assembly is a complex and an energy consuming process. Many controls exist to make it possible a fine-tuning of ribosome production adapted to cell needs. In this review, we describe recent advances in the characterisation of the links occurring between ribosome synthesis and cell proliferation control. Defects in ribosome biogenesis directly impede cellular cycle and slow-down proliferation. Among the different factors involved, we could define the 5S particle, a ribosome sub-complex, as a key-regulator of p53 and other tumour suppressors such as pRB. This cross-talk between ribosome neogenesis defects and proliferation and cellular cycle also involves other cell cycle controls such as p14ARF, SRSF1 or PRAS40 pathways. These data place ribosome synthesis at the heart of cell proliferation and offer new therapeutic strategies against cancer.
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Affiliation(s)
- Clément Madru
- Laboratoire de Cristallographie et RMN Biologiques, UMR, CNRS 8015, Université Paris Descartes, Faculté de Pharmacie, Sorbonne Paris Cité, 75006 Paris, France
| | - Nicolas Leulliot
- Laboratoire de Cristallographie et RMN Biologiques, UMR, CNRS 8015, Université Paris Descartes, Faculté de Pharmacie, Sorbonne Paris Cité, 75006 Paris, France
| | - Simon Lebaron
- Laboratoire de Cristallographie et RMN Biologiques, UMR, CNRS 8015, Université Paris Descartes, Faculté de Pharmacie, Sorbonne Paris Cité, 75006 Paris, France - Institut national de la santé et de la recherche médicale, Paris, France
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18
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Eukaryotic ribosome assembly, transport and quality control. Nat Struct Mol Biol 2017; 24:689-699. [PMID: 28880863 DOI: 10.1038/nsmb.3454] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 07/27/2017] [Indexed: 12/18/2022]
Abstract
Eukaryotic ribosome synthesis is a complex, energy-consuming process that takes place across the nucleolus, nucleoplasm and cytoplasm and requires more than 200 conserved assembly factors. Here, we discuss mechanisms by which the ribosome assembly and nucleocytoplasmic transport machineries collaborate to produce functional ribosomes. We also highlight recent cryo-EM studies that provided unprecedented snapshots of ribosomes during assembly and quality control.
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19
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Ghalei H, Trepreau J, Collins JC, Bhaskaran H, Strunk BS, Karbstein K. The ATPase Fap7 Tests the Ability to Carry Out Translocation-like Conformational Changes and Releases Dim1 during 40S Ribosome Maturation. Mol Cell 2017; 67:990-1000.e3. [PMID: 28890337 PMCID: PMC6192259 DOI: 10.1016/j.molcel.2017.08.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 07/08/2017] [Accepted: 08/11/2017] [Indexed: 01/18/2023]
Abstract
Late in their maturation, nascent small (40S) ribosomal subunits bind 60S subunits to produce 80S-like ribosomes. Because of the analogy of this translation-like cycle to actual translation, and because 80S-like ribosomes do not produce any protein, it has been suggested that this represents a quality control mechanism for subunit functionality. Here we use genetic and biochemical experiments to show that the essential ATPase Fap7 promotes formation of the rotated state, a key intermediate in translocation, thereby releasing the essential assembly factor Dim1 from pre-40S subunits. Bypassing this quality control step produces defects in reading frame maintenance. These results show how progress in the maturation cascade is linked to a test for a key functionality of 40S ribosomes: their ability to translocate the mRNA⋅tRNA pair. Furthermore, our data demonstrate for the first time that the translation-like cycle is a quality control mechanism that ensures the fidelity of the cellular ribosome pool.
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Affiliation(s)
- Homa Ghalei
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Juliette Trepreau
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Jason C Collins
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Hari Bhaskaran
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Bethany S Strunk
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Katrin Karbstein
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, FL 33458, USA.
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20
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Tomecki R, Sikorski PJ, Zakrzewska-Placzek M. Comparison of preribosomal RNA processing pathways in yeast, plant and human cells - focus on coordinated action of endo- and exoribonucleases. FEBS Lett 2017; 591:1801-1850. [PMID: 28524231 DOI: 10.1002/1873-3468.12682] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 05/14/2017] [Accepted: 05/15/2017] [Indexed: 12/17/2022]
Abstract
Proper regulation of ribosome biosynthesis is mandatory for cellular adaptation, growth and proliferation. Ribosome biogenesis is the most energetically demanding cellular process, which requires tight control. Abnormalities in ribosome production have severe consequences, including developmental defects in plants and genetic diseases (ribosomopathies) in humans. One of the processes occurring during eukaryotic ribosome biogenesis is processing of the ribosomal RNA precursor molecule (pre-rRNA), synthesized by RNA polymerase I, into mature rRNAs. It must not only be accurate but must also be precisely coordinated with other phenomena leading to the synthesis of functional ribosomes: RNA modification, RNA folding, assembly with ribosomal proteins and nucleocytoplasmic RNP export. A multitude of ribosome biogenesis factors ensure that these events take place in a correct temporal order. Among them are endo- and exoribonucleases involved in pre-rRNA processing. Here, we thoroughly present a wide spectrum of ribonucleases participating in rRNA maturation, focusing on their biochemical properties, regulatory mechanisms and substrate specificity. We also discuss cooperation between various ribonucleolytic activities in particular stages of pre-rRNA processing, delineating major similarities and differences between three representative groups of eukaryotes: yeast, plants and humans.
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Affiliation(s)
- Rafal Tomecki
- Laboratory of RNA Biology and Functional Genomics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.,Department of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Poland
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21
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Espinar-Marchena FJ, Babiano R, Cruz J. Placeholder factors in ribosome biogenesis: please, pave my way. MICROBIAL CELL 2017; 4:144-168. [PMID: 28685141 PMCID: PMC5425277 DOI: 10.15698/mic2017.05.572] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The synthesis of cytoplasmic eukaryotic ribosomes is an extraordinarily energy-demanding cellular activity that occurs progressively from the nucleolus to the cytoplasm. In the nucleolus, precursor rRNAs associate with a myriad of trans-acting factors and some ribosomal proteins to form pre-ribosomal particles. These factors include snoRNPs, nucleases, ATPases, GTPases, RNA helicases, and a vast list of proteins with no predicted enzymatic activity. Their coordinate activity orchestrates in a spatiotemporal manner the modification and processing of precursor rRNAs, the rearrangement reactions required for the formation of productive RNA folding intermediates, the ordered assembly of the ribosomal proteins, and the export of pre-ribosomal particles to the cytoplasm; thus, providing speed, directionality and accuracy to the overall process of formation of translation-competent ribosomes. Here, we review a particular class of trans-acting factors known as "placeholders". Placeholder factors temporarily bind selected ribosomal sites until these have achieved a structural context that is appropriate for exchanging the placeholder with another site-specific binding factor. By this strategy, placeholders sterically prevent premature recruitment of subsequently binding factors, premature formation of structures, avoid possible folding traps, and act as molecular clocks that supervise the correct progression of pre-ribosomal particles into functional ribosomal subunits. We summarize the current understanding of those factors that delay the assembly of distinct ribosomal proteins or subsequently bind key sites in pre-ribosomal particles. We also discuss recurrent examples of RNA-protein and protein-protein mimicry between rRNAs and/or factors, which have clear functional implications for the ribosome biogenesis pathway.
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Affiliation(s)
- Francisco J Espinar-Marchena
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, E-41013, Seville, Spain
| | - Reyes Babiano
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, E-41013, Seville, Spain.,Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, E-41013, Seville, Spain
| | - Jesús Cruz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, E-41013, Seville, Spain
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22
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Self-Referential Encoding on Modules of Anticodon Pairs-Roots of the Biological Flow System. Life (Basel) 2017; 7:life7020016. [PMID: 28383509 PMCID: PMC5492138 DOI: 10.3390/life7020016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 03/24/2017] [Accepted: 03/26/2017] [Indexed: 12/22/2022] Open
Abstract
The proposal that the genetic code was formed on the basis of (proto)tRNA Dimer-Directed Protein Synthesis is reviewed and updated. The tRNAs paired through the anticodon loops are an indication on the process. Dimers are considered mimics of the ribosomes-structures that hold tRNAs together and facilitate the transferase reaction, and of the translation process-anticodons are at the same time codons for each other. The primitive protein synthesis system gets stabilized when the product peptides are stable and apt to bind the producers therewith establishing a self-stimulating production cycle. The chronology of amino acid encoding starts with Glycine and Serine, indicating the metabolic support of the Glycine-Serine C1-assimilation pathway, which is also consistent with evidence on origins of bioenergetics mechanisms. Since it is not possible to reach for substrates simpler than C1 and compounds in the identified pathway are apt for generating the other central metabolic routes, it is considered that protein synthesis is the beginning and center of a succession of sink-effective mechanisms that drive the formation and evolution of the metabolic flow system. Plasticity and diversification of proteins construct the cellular system following the orientation given by the flow and implementing it. Nucleic acid monomers participate in bioenergetics and the polymers are conservative memory systems for the synthesis of proteins. Protoplasmic fission is the final sink-effective mechanism, part of cell reproduction, guaranteeing that proteins don't accumulate to saturation, which would trigger inhibition.
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23
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Peña C, Schütz S, Fischer U, Chang Y, Panse VG. Prefabrication of a ribosomal protein subcomplex essential for eukaryotic ribosome formation. eLife 2016; 5. [PMID: 27929371 PMCID: PMC5148605 DOI: 10.7554/elife.21755] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 11/29/2016] [Indexed: 01/21/2023] Open
Abstract
Spatial clustering of ribosomal proteins (r-proteins) through tertiary interactions is a striking structural feature of the eukaryotic ribosome. However, the functional importance of these intricate inter-connections, and how they are established is currently unclear. Here, we reveal that a conserved ATPase, Fap7, organizes interactions between neighboring r-proteins uS11 and eS26 prior to their delivery to the earliest ribosome precursor, the 90S. In vitro, uS11 only when bound to Fap7 becomes competent to recruit eS26 through tertiary contacts found between these r-proteins on the mature ribosome. Subsequently, Fap7 ATPase activity unloads the uS11:eS26 subcomplex onto its rRNA binding site, and therefore ensures stoichiometric integration of these r-proteins into the 90S. Fap7-depletion in vivo renders uS11 susceptible to proteolysis, and precludes eS26 incorporation into the 90S. Thus, prefabrication of a native-like r-protein subcomplex drives efficient and accurate construction of the eukaryotic ribosome. DOI:http://dx.doi.org/10.7554/eLife.21755.001
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Affiliation(s)
- Cohue Peña
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.,Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Sabina Schütz
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Ute Fischer
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Yiming Chang
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Vikram G Panse
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
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24
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Pillet B, Mitterer V, Kressler D, Pertschy B. Hold on to your friends: Dedicated chaperones of ribosomal proteins: Dedicated chaperones mediate the safe transfer of ribosomal proteins to their site of pre-ribosome incorporation. Bioessays 2016; 39:1-12. [PMID: 27859409 DOI: 10.1002/bies.201600153] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Eukaryotic ribosomes are assembled from their components, the ribosomal RNAs and ribosomal proteins, in a tremendously complex, multi-step process, which primarily takes place in the nuclear compartment. Therefore, most ribosomal proteins have to travel from the cytoplasm to their incorporation site on pre-ribosomes within the nucleus. However, due to their particular characteristics, such as a highly basic amino acid composition and the presence of unstructured extensions, ribosomal proteins are especially prone to aggregation and degradation in their unassembled state, hence specific mechanisms must operate to ensure their safe delivery. Recent studies have uncovered a group of proteins, termed dedicated chaperones, specialized in accompanying and guarding individual ribosomal proteins. In this essay, we review how these dedicated chaperones utilize different folds to interact with their ribosomal protein clients and how they ensure their soluble expression and interconnect their intracellular transport with their efficient assembly into pre-ribosomes.
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Affiliation(s)
- Benjamin Pillet
- Unit of Biochemistry, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Valentin Mitterer
- Institut für Molekulare Biowissenschaften, Universität Graz, Graz, Austria
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Brigitte Pertschy
- Institut für Molekulare Biowissenschaften, Universität Graz, Graz, Austria
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25
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Larburu N, Montellese C, O'Donohue MF, Kutay U, Gleizes PE, Plisson-Chastang C. Structure of a human pre-40S particle points to a role for RACK1 in the final steps of 18S rRNA processing. Nucleic Acids Res 2016; 44:8465-78. [PMID: 27530427 PMCID: PMC5041492 DOI: 10.1093/nar/gkw714] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 07/28/2016] [Accepted: 08/06/2016] [Indexed: 01/24/2023] Open
Abstract
Synthesis of ribosomal subunits in eukaryotes is a complex and tightly regulated process that has been mostly characterized in yeast. The discovery of a growing number of diseases linked to defects in ribosome biogenesis calls for a deeper understanding of these mechanisms and of the specificities of human ribosome maturation. We present the 19 Å resolution cryo-EM reconstruction of a cytoplasmic precursor to the human small ribosomal subunit, purified by using the tagged ribosome biogenesis factor LTV1 as bait. Compared to yeast pre-40S particles, this first three-dimensional structure of a human 40S subunit precursor shows noticeable differences with respect to the position of ribosome biogenesis factors and uncovers the early deposition of the ribosomal protein RACK1 during subunit maturation. Consistently, RACK1 is required for efficient processing of the 18S rRNA 3'-end, which might be related to its role in translation initiation. This first structural analysis of a human pre-ribosomal particle sets the grounds for high-resolution studies of conformational transitions accompanying ribosomal subunit maturation.
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MESH Headings
- Conserved Sequence
- Cryoelectron Microscopy
- Cytoplasm/metabolism
- GTP-Binding Proteins/metabolism
- HEK293 Cells
- HeLa Cells
- Humans
- Models, Molecular
- Neoplasm Proteins/metabolism
- Organelle Biogenesis
- Protein Binding
- RNA Processing, Post-Transcriptional/genetics
- RNA, Ribosomal, 18S/genetics
- Receptors for Activated C Kinase
- Receptors, Cell Surface/metabolism
- Ribosomal Proteins/metabolism
- Ribosome Subunits, Small, Eukaryotic/chemistry
- Ribosome Subunits, Small, Eukaryotic/metabolism
- Ribosome Subunits, Small, Eukaryotic/ultrastructure
- Saccharomyces cerevisiae/metabolism
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Affiliation(s)
- Natacha Larburu
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | | | - Marie-Françoise O'Donohue
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - Ulrike Kutay
- Institut für Biochemie, ETH Zürich, CH-8093 Zurich, Switzerland
| | - Pierre-Emmanuel Gleizes
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - Célia Plisson-Chastang
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
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26
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Bai D, Zhang J, Li T, Hang R, Liu Y, Tian Y, Huang D, Qu L, Cao X, Ji J, Zheng X. The ATPase hCINAP regulates 18S rRNA processing and is essential for embryogenesis and tumour growth. Nat Commun 2016; 7:12310. [PMID: 27477389 PMCID: PMC4974663 DOI: 10.1038/ncomms12310] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 06/20/2016] [Indexed: 12/29/2022] Open
Abstract
Dysfunctions in ribosome biogenesis cause developmental defects and increased cancer susceptibility; however, the connection between ribosome assembly and tumorigenesis remains unestablished. Here we show that hCINAP (also named AK6) is required for human 18S rRNA processing and 40S subunit assembly. Homozygous CINAP−/− mice show embryonic lethality. The heterozygotes are viable and show defects in 18S rRNA processing, whereas no delayed cell growth is observed. However, during rapid growth, CINAP haploinsufficiency impairs protein synthesis. Consistently, hCINAP depletion in fast-growing cancer cells inhibits ribosome assembly and abolishes tumorigenesis. These data demonstrate that hCINAP reduction is a specific rate-limiting controller during rapid growth. Notably, hCINAP is highly expressed in cancers and correlated with a worse prognosis. Genome-wide polysome profiling shows that hCINAP selectively modulates cancer-associated translatome to promote malignancy. Our results connect the role of hCINAP in ribosome assembly with tumorigenesis. Modulation of hCINAP expression may be a promising target for cancer therapy. Perturbations in ribosome biogenesis affect development and increase cancer susceptibility. Here, the authors show that hCINAP is required for 18S rRNA processing, is highly expressed in cancers, and promotes cancer cell growth by upregulating the translation of cancer-associated genes.
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Affiliation(s)
- Dongmei Bai
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Jinfang Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Tingting Li
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Runlai Hang
- State key Laboratory of Plant Genetics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.,College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100039, China
| | - Yong Liu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Yonglu Tian
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Dadu Huang
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Linglong Qu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Xiaofeng Cao
- State key Laboratory of Plant Genetics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.,College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100039, China
| | - Jiafu Ji
- Key Laboratory of Carcinogenesis and Translational Research, Department of Gastrointestinal Surgery, Peking University Caner Hospital and Institute, Beijing 100142, China
| | - Xiaofeng Zheng
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
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27
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Abstract
In this study, Madru et al. determined the structure of the ribosome-bound Rpf2–Rrs1 complex, a complex essential for the assembly of the 5S RNA in ribosomes, and characterized the free and 5S-bound structures. The findings show that Rpf2 and Rrs1 establish a network of protein–protein and protein–RNA interactions with the 5S RNA and specific preribosomes, thus providing novel insight into ribosome biogenesis. In eukaryotes, three of the four ribosomal RNAs (rRNAs)—the 5.8S, 18S, and 25S/28S rRNAs—are processed from a single pre-rRNA transcript and assembled into ribosomes. The fourth rRNA, the 5S rRNA, is transcribed by RNA polymerase III and is assembled into the 5S ribonucleoprotein particle (RNP), containing ribosomal proteins Rpl5/uL18 and Rpl11/uL5, prior to its incorporation into preribosomes. In mammals, the 5S RNP is also a central regulator of the homeostasis of the tumor suppressor p53. The nucleolar localization of the 5S RNP and its assembly into preribosomes are performed by a specialized complex composed of Rpf2 and Rrs1 in yeast or Bxdc1 and hRrs1 in humans. Here we report the structural and functional characterization of the Rpf2–Rrs1 complex alone, in complex with the 5S RNA, and within pre-60S ribosomes. We show that the Rpf2–Rrs1 complex contains a specialized 5S RNA E-loop-binding module, contacts the Rpl5 protein, and also contacts the ribosome assembly factor Rsa4 and the 25S RNA. We propose that the Rpf2–Rrs1 complex establishes a network of interactions that guide the incorporation of the 5S RNP in preribosomes in the initial conformation prior to its rotation to form the central protuberance found in the mature large ribosomal subunit.
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28
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Pausch P, Singh U, Ahmed YL, Pillet B, Murat G, Altegoer F, Stier G, Thoms M, Hurt E, Sinning I, Bange G, Kressler D. Co-translational capturing of nascent ribosomal proteins by their dedicated chaperones. Nat Commun 2015; 6:7494. [PMID: 26112308 PMCID: PMC4491177 DOI: 10.1038/ncomms8494] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 05/14/2015] [Indexed: 12/11/2022] Open
Abstract
Exponentially growing yeast cells produce every minute >160,000 ribosomal proteins. Owing to their difficult physicochemical properties, the synthesis of assembly-competent ribosomal proteins represents a major challenge. Recent evidence highlights that dedicated chaperone proteins recognize the N-terminal regions of ribosomal proteins and promote their soluble expression and delivery to the assembly site. Here we explore the intuitive possibility that ribosomal proteins are captured by dedicated chaperones in a co-translational manner. Affinity purification of four chaperones (Rrb1, Syo1, Sqt1 and Yar1) selectively enriched the mRNAs encoding their specific ribosomal protein clients (Rpl3, Rpl5, Rpl10 and Rps3). X-ray crystallography reveals how the N-terminal, rRNA-binding residues of Rpl10 are shielded by Sqt1's WD-repeat β-propeller, providing mechanistic insight into the incorporation of Rpl10 into pre-60S subunits. Co-translational capturing of nascent ribosomal proteins by dedicated chaperones constitutes an elegant mechanism to prevent unspecific interactions and aggregation of ribosomal proteins on their road to incorporation. The synthesis of ribosomes requires the orderly assembly of many proteins and large RNA molecules, a process that involves several assembly factors. Here the authors show that dedicated chaperones capture the N termini of specific nascent ribosomal proteins to promote folding and assembly into maturing ribosomes.
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Affiliation(s)
- Patrick Pausch
- LOEWE Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße, Marburg D-35043, Germany
| | - Ujjwala Singh
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, Fribourg CH-1700, Switzerland
| | - Yasar Luqman Ahmed
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg D-61920, Germany
| | - Benjamin Pillet
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, Fribourg CH-1700, Switzerland
| | - Guillaume Murat
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, Fribourg CH-1700, Switzerland
| | - Florian Altegoer
- LOEWE Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße, Marburg D-35043, Germany
| | - Gunter Stier
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg D-61920, Germany
| | - Matthias Thoms
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg D-61920, Germany
| | - Ed Hurt
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg D-61920, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg D-61920, Germany
| | - Gert Bange
- LOEWE Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße, Marburg D-35043, Germany
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, Fribourg CH-1700, Switzerland
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29
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Lafontaine DLJ. Noncoding RNAs in eukaryotic ribosome biogenesis and function. Nat Struct Mol Biol 2015; 22:11-9. [PMID: 25565028 DOI: 10.1038/nsmb.2939] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 11/26/2014] [Indexed: 12/22/2022]
Abstract
The ribosome, central to protein synthesis in all cells, is a complex multicomponent assembly with rRNA at its functional core. During the process of ribosome biogenesis, diverse noncoding RNAs participate in controlling the quantity and quality of this rRNA. In this Review, I discuss the multiple roles assumed by noncoding RNAs during the different steps of ribosome biogenesis and how they contribute to the generation of ribosome heterogeneity, which affects normal and pathophysiological processes.
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Affiliation(s)
- Denis L J Lafontaine
- RNA Molecular Biology, Fonds National de la Recherche Scientifique, Université Libre de Bruxelles, Brussels, Belgium
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30
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Abstract
The proteome of cells is synthesized by ribosomes, complex ribonucleoproteins that in eukaryotes contain 79-80 proteins and four ribosomal RNAs (rRNAs) more than 5,400 nucleotides long. How these molecules assemble together and how their assembly is regulated in concert with the growth and proliferation of cells remain important unanswered questions. Here, we review recently emerging principles to understand how eukaryotic ribosomal proteins drive ribosome assembly in vivo. Most ribosomal proteins assemble with rRNA cotranscriptionally; their association with nascent particles is strengthened as assembly proceeds. Each subunit is assembled hierarchically by sequential stabilization of their subdomains. The active sites of both subunits are constructed last, perhaps to prevent premature engagement of immature ribosomes with active subunits. Late-assembly intermediates undergo quality-control checks for proper function. Mutations in ribosomal proteins that affect mostly late steps lead to ribosomopathies, diseases that include a spectrum of cell type-specific disorders that often transition from hypoproliferative to hyperproliferative growth.
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Affiliation(s)
- Jesus de la Cruz
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, E-41013 Sevilla, Spain
- Departamento de Genetica, Universidad de Sevilla, E-41013 Sevilla, Spain
| | - Katrin Karbstein
- Department of Cancer Biology, The Scripps Research Institute, Jupiter, Florida 33458
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
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31
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Burroughs AM, Aravind L. Analysis of two domains with novel RNA-processing activities throws light on the complex evolution of ribosomal RNA biogenesis. Front Genet 2014; 5:424. [PMID: 25566315 PMCID: PMC4275035 DOI: 10.3389/fgene.2014.00424] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 11/19/2014] [Indexed: 11/13/2022] Open
Abstract
Ribosomal biogenesis has been extensively investigated, especially to identify the elusive nucleases and cofactors involved in the complex rRNA processing events in eukaryotes. Large-scale screens in yeast identified two biochemically uncharacterized proteins, TSR3 and TSR4, as being key players required for rRNA maturation. Using multiple computational approaches we identify the conserved domains comprising these proteins and establish sequence and structural features providing novel insights regarding their roles. TSR3 is unified with the DTW domain into a novel superfamily of predicted enzymatic domains, with the balance of the available evidence pointing toward an RNase role with the archaeo-eukaryotic TSR3 proteins processing rRNA and the bacterial versions potentially processing tRNA. TSR4, its other eukaryotic homologs PDCD2/rp-8, PDCD2L, Zfrp8, and trus, the predominantly bacterial DUF1963 proteins, and other uncharacterized proteins are unified into a new domain superfamily, which arose from an ancient duplication event of a strand-swapped, dimer-forming all-beta unit. We identify conserved features mediating protein-protein interactions (PPIs) and propose a potential chaperone-like function. While contextual evidence supports a conserved role in ribosome biogenesis for the eukaryotic TSR4-related proteins, there is no evidence for such a role for the bacterial versions. Whereas TSR3-related proteins can be traced to the last universal common ancestor (LUCA) with a well-supported archaeo-eukaryotic branch, TSR4-related proteins of eukaryotes are derived from within the bacterial radiation of this superfamily, with archaea entirely lacking them. This provides evidence for “systems admixture,” which followed the early endosymbiotic event, playing a key role in the emergence of the uniquely eukaryotic ribosome biogenesis process.
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Affiliation(s)
- A Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health Bethesda, MD, USA
| | - L Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health Bethesda, MD, USA
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32
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Turowski TW, Lebaron S, Zhang E, Peil L, Dudnakova T, Petfalski E, Granneman S, Rappsilber J, Tollervey D. Rio1 mediates ATP-dependent final maturation of 40S ribosomal subunits. Nucleic Acids Res 2014; 42:12189-99. [PMID: 25294836 PMCID: PMC4231747 DOI: 10.1093/nar/gku878] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
During the last step in 40S ribosome subunit biogenesis, the PIN-domain endonuclease Nob1 cleaves the 20S pre-rRNA at site D, to form the mature 18S rRNAs. Here we report that cleavage occurs in particles that have largely been stripped of previously characterized pre-40S components, but retain the endonuclease Nob1, its binding partner Pno1 (Dim2) and the atypical ATPase Rio1. Within the Rio1-associated pre-40S particles, in vitro pre-rRNA cleavage was strongly stimulated by ATP and required nucleotide binding by Rio1. In vivo binding sites for Rio1, Pno1 and Nob1 were mapped by UV cross-linking in actively growing cells. Nob1 and Pno1 bind overlapping regions within the internal transcribed spacer 1, and both bind directly over cleavage site D. Binding sites for Rio1 were within the core of the 18S rRNA, overlapping tRNA interaction sites and distinct from the related kinase Rio2. Site D cleavage occurs within pre-40S-60S complexes and Rio1-associated particles efficiently assemble into these complexes, whereas Pno1 appeared to be depleted relative to Nob1. We speculate that Rio1-mediated dissociation of Pno1 from cleavage site D is the trigger for final 18S rRNA maturation.
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Affiliation(s)
- Tomasz W Turowski
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Simon Lebaron
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Elodie Zhang
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Lauri Peil
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Tatiana Dudnakova
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Elisabeth Petfalski
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Sander Granneman
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Juri Rappsilber
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - David Tollervey
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
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