1
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Steiner A, Favre S, Mack M, Hausharter A, Pillet B, Hafner J, Mitterer V, Kressler D, Pertschy B, Zierler I. Dissecting the Nuclear Import of the Ribosomal Protein Rps2 (uS5). Biomolecules 2023; 13:1127. [PMID: 37509163 PMCID: PMC10377357 DOI: 10.3390/biom13071127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 07/06/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
The ribosome is assembled in a complex process mainly taking place in the nucleus. Consequently, newly synthesized ribosomal proteins have to travel from the cytoplasm into the nucleus, where they are incorporated into nascent ribosomal subunits. In this study, we set out to investigate the mechanism mediating nuclear import of the small subunit ribosomal protein Rps2. We demonstrate that an internal region in Rps2, ranging from amino acids 76 to 145, is sufficient to target a 3xyEGFP reporter to the nucleus. The importin-β Pse1 interacts with this Rps2 region and is involved in its import, with Rps2 residues arginine 95, arginine 97, and lysine 99 being important determinants for both Pse1 binding and nuclear localization. Moreover, our data reveal a second import mechanism involving the N-terminal region of Rps2, which depends on the presence of basic residues within amino acids 10 to 28. This Rps2 segment overlaps with the binding site of the dedicated chaperone Tsr4; however, the nuclear import of Rps2 via the internal as well as the N-terminal nuclear-targeting element does not depend on Tsr4. Taken together, our study has unveiled hitherto undescribed nuclear import signals, showcasing the versatility of the mechanisms coordinating the nuclear import of ribosomal proteins.
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Affiliation(s)
- Andreas Steiner
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria; (A.S.); (M.M.); (V.M.)
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Sébastien Favre
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland; (S.F.); (B.P.); (D.K.)
| | - Maximilian Mack
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria; (A.S.); (M.M.); (V.M.)
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Annika Hausharter
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria; (A.S.); (M.M.); (V.M.)
| | - Benjamin Pillet
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland; (S.F.); (B.P.); (D.K.)
| | - Jutta Hafner
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria; (A.S.); (M.M.); (V.M.)
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Valentin Mitterer
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria; (A.S.); (M.M.); (V.M.)
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland; (S.F.); (B.P.); (D.K.)
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria; (A.S.); (M.M.); (V.M.)
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Ingrid Zierler
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria; (A.S.); (M.M.); (V.M.)
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
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2
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Golob-Schwarzl N, Schweiger C, Koller C, Krassnig S, Gogg-Kamerer M, Gantenbein N, Toeglhofer AM, Wodlej C, Bergler H, Pertschy B, Uranitsch S, Holter M, El-Heliebi A, Fuchs J, Punschart A, Stiegler P, Keil M, Hoffmann J, Henderson D, Lehrach H, Reinhard C, Regenbrecht C, Schicho R, Fickert P, Lax S, Haybaeck J. Correction: Separation of low and high grade colon and rectum carcinoma by eukaryotic translation initiation factors 1, 5 and 6. Oncotarget 2023; 14:83-84. [PMID: 36745526 PMCID: PMC9901560 DOI: 10.18632/oncotarget.28115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Nicole Golob-Schwarzl
- 1Institute of Pathology, Medical University of Graz, Graz, Austria,2Center for Biomarker Research in Medicine, Graz, Austria
| | | | - Carina Koller
- 1Institute of Pathology, Medical University of Graz, Graz, Austria
| | | | | | - Nadine Gantenbein
- 1Institute of Pathology, Medical University of Graz, Graz, Austria,2Center for Biomarker Research in Medicine, Graz, Austria
| | | | - Christina Wodlej
- 1Institute of Pathology, Medical University of Graz, Graz, Austria,2Center for Biomarker Research in Medicine, Graz, Austria
| | - Helmut Bergler
- 3Institute of Molecular Biosciences, Karl-Franzens-University of Graz, Graz, Austria
| | - Brigitte Pertschy
- 3Institute of Molecular Biosciences, Karl-Franzens-University of Graz, Graz, Austria
| | - Stefan Uranitsch
- 4Department of Surgery, Hospital Brothers of Charity Graz, Graz, Austria
| | - Magdalena Holter
- 5Institute of Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria
| | - Amin El-Heliebi
- 6Institute of Cell Biology, Histology and Embryology, Medical University Graz, Graz, Austria
| | - Julia Fuchs
- 6Institute of Cell Biology, Histology and Embryology, Medical University Graz, Graz, Austria
| | | | - Philipp Stiegler
- 7Department of Surgery, Medical University of Graz, Graz, Austria
| | - Marlen Keil
- 8Experimental Pharmacology & Oncology Berlin GmbH-Berlin-Buch, Berlin, Germany
| | - Jens Hoffmann
- 8Experimental Pharmacology & Oncology Berlin GmbH-Berlin-Buch, Berlin, Germany
| | | | - Hans Lehrach
- 10Max Planck Institute for Molecular Genetics, Berlin, Germany
| | | | | | - Rudolf Schicho
- 13Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - Peter Fickert
- 14Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Sigurd Lax
- 15Department of Pathology, Hospital Graz South-West, Austria
| | - Johannes Haybaeck
- 1Institute of Pathology, Medical University of Graz, Graz, Austria,2Center for Biomarker Research in Medicine, Graz, Austria,16Department of Pathology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany,Correspondence to:Johannes Haybaeck, email:
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3
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Bhutada P, Favre S, Jaafar M, Hafner J, Liesinger L, Unterweger S, Bischof K, Darnhofer B, Siva Sankar D, Rechberger G, Abou Merhi R, Lebaron S, Birner-Gruenberger R, Kressler D, Henras AK, Pertschy B. Rbp95 binds to 25S rRNA helix H95 and cooperates with the Npa1 complex during early pre-60S particle maturation. Nucleic Acids Res 2022; 50:10053-10077. [PMID: 36018804 PMCID: PMC9508819 DOI: 10.1093/nar/gkac724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 08/05/2022] [Accepted: 08/12/2022] [Indexed: 11/21/2022] Open
Abstract
Eukaryotic ribosome synthesis involves more than 200 assembly factors, which promote ribosomal RNA (rRNA) processing, modification and folding, and assembly of ribosomal proteins. The formation and maturation of the earliest pre-60S particles requires structural remodeling by the Npa1 complex, but is otherwise still poorly understood. Here, we introduce Rbp95 (Ycr016w), a constituent of early pre-60S particles, as a novel ribosome assembly factor. We show that Rbp95 is both genetically and physically linked to most Npa1 complex members and to ribosomal protein Rpl3. We demonstrate that Rbp95 is an RNA-binding protein containing two independent RNA-interacting domains. In vivo, Rbp95 associates with helix H95 in the 3′ region of the 25S rRNA, in close proximity to the binding sites of Npa1 and Rpl3. Additionally, Rbp95 interacts with several snoRNAs. The absence of Rbp95 results in alterations in the protein composition of early pre-60S particles. Moreover, combined mutation of Rbp95 and Npa1 complex members leads to a delay in the maturation of early pre-60S particles. We propose that Rbp95 acts together with the Npa1 complex during early pre-60S maturation, potentially by promoting pre-rRNA folding events within pre-60S particles.
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Affiliation(s)
- Priya Bhutada
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Sébastien Favre
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Mariam Jaafar
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France.,Genomic Stability and Biotherapy (GSBT) Laboratory, Faculty of Sciences, Rafik Hariri Campus, Lebanese University, Beirut, Lebanon
| | - Jutta Hafner
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Laura Liesinger
- BioTechMed-Graz, Graz, Austria.,Diagnostic and Research Institute of Pathology, Medical University of Graz, 8010 Graz, Austria
| | - Stefan Unterweger
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Karin Bischof
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Barbara Darnhofer
- BioTechMed-Graz, Graz, Austria.,Diagnostic and Research Institute of Pathology, Medical University of Graz, 8010 Graz, Austria
| | - Devanarayanan Siva Sankar
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Gerald Rechberger
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Raghida Abou Merhi
- Genomic Stability and Biotherapy (GSBT) Laboratory, Faculty of Sciences, Rafik Hariri Campus, Lebanese University, Beirut, Lebanon
| | - Simon Lebaron
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Ruth Birner-Gruenberger
- BioTechMed-Graz, Graz, Austria.,Diagnostic and Research Institute of Pathology, Medical University of Graz, 8010 Graz, Austria.,Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/E164, 1060 Vienna, Austria
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Anthony K Henras
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
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4
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Rössler I, Weigl S, Fernández-Fernández J, Martín-Villanueva S, Strauss D, Hurt E, de la Cruz J, Pertschy B. The C-terminal tail of ribosomal protein Rps15 is engaged in cytoplasmic pre-40S maturation. RNA Biol 2022; 19:560-574. [PMID: 35438042 PMCID: PMC9037480 DOI: 10.1080/15476286.2022.2064073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The small ribosomal subunit protein Rps15/uS19 is involved in early nucleolar ribosome biogenesis and subsequent nuclear export of pre-40S particles to the cytoplasm. In addition, the C-terminal tail of Rps15 was suggested to play a role in mature ribosomes, namely during translation elongation. Here, we show that Rps15 not only functions in nucleolar ribosome assembly but also in cytoplasmic pre-40S maturation, which is indicated by a strong genetic interaction between Rps15 and the 40S assembly factor Ltv1. Specifically, mutations either in the globular or C-terminal domain of Rps15 when combined with the non-essential ltv1 null allele are lethal or display a strong growth defect. However, not only rps15 ltv1 double mutants but also single rps15 C-terminal deletion mutants exhibit an accumulation of the 20S pre-rRNA in the cytoplasm, indicative of a cytoplasmic pre-40S maturation defect. Since in pre-40S particles, the C-terminal tail of Rps15 is positioned between assembly factors Rio2 and Tsr1, we further tested whether Tsr1 is genetically linked to Rps15, which indeed could be demonstrated. Thus, the integrity of the Rps15 C-terminal tail plays an important role during late pre-40S maturation, perhaps in a quality control step to ensure that only 40S ribosomal subunits with functional Rps15 C-terminal tail can efficiently enter translation. As mutations in the C-terminal tail of human RPS15 have been observed in connection with chronic lymphocytic leukaemia, it is possible that apart from defects in translation, an impaired late pre-40S maturation step in the cytoplasm could also be a reason for this disease.
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Affiliation(s)
- Ingrid Rössler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Sarah Weigl
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - José Fernández-Fernández
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Sara Martín-Villanueva
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Daniela Strauss
- Biochemistry Center BZH, Heidelberg University, Heidelberg, Germany
| | - Ed Hurt
- Biochemistry Center BZH, Heidelberg University, Heidelberg, Germany
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
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5
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Abstract
Eukaryotic ribosome biogenesis involves the synthesis of ribosomal RNA (rRNA) and its stepwise folding into the unique structure present in mature ribosomes. rRNA folding starts already co-transcriptionally in the nucleolus and continues when pre-ribosomal particles further maturate in the nucleolus and upon their transit to the nucleoplasm and cytoplasm. While the approximate order of folding of rRNA subdomains is known, especially from cryo-EM structures of pre-ribosomal particles, the actual mechanisms of rRNA folding are less well understood. Both small nucleolar RNAs (snoRNAs) and proteins have been implicated in rRNA folding. snoRNAs hybridize to precursor rRNAs (pre-rRNAs) and thereby prevent premature folding of the respective rRNA elements. Ribosomal proteins (r-proteins) and ribosome assembly factors might have a similar function by binding to rRNA elements and preventing their premature folding. Besides that, a small group of ribosome assembly factors are thought to play a more active role in rRNA folding. In particular, multiple RNA helicases participate in individual ribosome assembly steps, where they are believed to coordinate RNA folding/unfolding events or the release of proteins from the rRNA. In this review, we summarize the current knowledge on mechanisms of RNA folding and on the specific function of the individual RNA helicases involved. As the yeast Saccharomyces cerevisiae is the organism in which ribosome biogenesis and the role of RNA helicases in this process is best studied, we focused our review on insights from this model organism, but also make comparisons to other organisms where applicable.
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Affiliation(s)
- Valentin Mitterer
- Biochemistry Center, Heidelberg University, Im Neuenheimer Feld 328, Heidelberg, Germany.,BioTechMed-Graz, Graz, Austria
| | - Brigitte Pertschy
- BioTechMed-Graz, Graz, Austria.,Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, Graz, Austria
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6
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Zhang F, Kerbl-Knapp J, Rodriguez Colman MJ, Meinitzer A, Macher T, Vujić N, Fasching S, Jany-Luig E, Korbelius M, Kuentzel KB, Mack M, Akhmetshina A, Pirchheim A, Paar M, Rinner B, Hörl G, Steyrer E, Stelzl U, Burgering B, Eisenberg T, Pertschy B, Kratky D, Madl T. Global analysis of protein arginine methylation. Cell Rep Methods 2021; 1:100016. [PMID: 35475236 PMCID: PMC9017121 DOI: 10.1016/j.crmeth.2021.100016] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/02/2021] [Accepted: 05/12/2021] [Indexed: 12/25/2022]
Abstract
Quantitative information about the levels and dynamics of post-translational modifications (PTMs) is critical for an understanding of cellular functions. Protein arginine methylation (ArgMet) is an important subclass of PTMs and is involved in a plethora of (patho)physiological processes. However, because of the lack of methods for global analysis of ArgMet, the link between ArgMet levels, dynamics, and (patho)physiology remains largely unknown. We utilized the high sensitivity and robustness of nuclear magnetic resonance (NMR) spectroscopy to develop a general method for the quantification of global protein ArgMet. Our NMR-based approach enables the detection of protein ArgMet in purified proteins, cells, organoids, and mouse tissues. We demonstrate that the process of ArgMet is a highly prevalent PTM and can be modulated by small-molecule inhibitors and metabolites and changes in cancer and during aging. Thus, our approach enables us to address a wide range of biological questions related to ArgMet in health and disease.
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Affiliation(s)
- Fangrong Zhang
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Jakob Kerbl-Knapp
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Maria J. Rodriguez Colman
- Oncode Institute and Department of Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Andreas Meinitzer
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, 8010 Graz, Austria
| | - Therese Macher
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Nemanja Vujić
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Sandra Fasching
- Institute of Pharmaceutical Sciences, University of Graz, 8010 Graz, Austria
| | - Evelyne Jany-Luig
- Institute of Pharmaceutical Sciences, University of Graz, 8010 Graz, Austria
| | - Melanie Korbelius
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Katharina B. Kuentzel
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Maximilian Mack
- BioTechMed-Graz, 8010 Graz, Austria
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
| | - Alena Akhmetshina
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Anita Pirchheim
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Margret Paar
- Otto-Loewi Research Center, Physiological Chemistry, Medical University of Graz, 8010 Graz, Austria
| | - Beate Rinner
- Division of Biomedical Research, Medical University of Graz, 8036 Graz, Austria
| | - Gerd Hörl
- Otto-Loewi Research Center, Physiological Chemistry, Medical University of Graz, 8010 Graz, Austria
| | - Ernst Steyrer
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Ulrich Stelzl
- BioTechMed-Graz, 8010 Graz, Austria
- Institute of Pharmaceutical Sciences, University of Graz, 8010 Graz, Austria
| | - Boudewijn Burgering
- Oncode Institute and Department of Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Tobias Eisenberg
- BioTechMed-Graz, 8010 Graz, Austria
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
- Field of Excellence BioHealth – University of Graz, Graz, Austria
| | - Brigitte Pertschy
- BioTechMed-Graz, 8010 Graz, Austria
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
- Field of Excellence BioHealth – University of Graz, Graz, Austria
| | - Dagmar Kratky
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Tobias Madl
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
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7
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Izghirean N, Waidacher C, Kittinger C, Chyba M, Koraimann G, Pertschy B, Zarfel G. Effects of Ribosomal Protein S10 Flexible Loop Mutations on Tetracycline and Tigecycline Susceptibility of Escherichia coli. Front Microbiol 2021; 12:663835. [PMID: 34220749 PMCID: PMC8249722 DOI: 10.3389/fmicb.2021.663835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 05/20/2021] [Indexed: 11/20/2022] Open
Abstract
Tigecycline is a tetracycline derivative that is being used as an antibiotic of last resort. Both tigecycline and tetracycline bind to the small (30S) ribosomal subunit and inhibit translation. Target mutations leading to resistance to these antibiotics have been identified both in the 16S ribosomal RNA and in ribosomal proteins S3 and S10 (encoded by the rpsJ gene). Several different mutations in the S10 flexible loop tip residue valine 57 (V57) have been observed in tigecycline-resistant Escherichia coli isolates. However, the role of these mutations in E. coli has not yet been characterized in a defined genetic background. In this study, we chromosomally integrated 10 different rpsJ mutations into E. coli, resulting in different exchanges or a deletion of S10 V57, and investigated the effects of the mutations on growth and tigecycline/tetracycline resistance. While one exchange, V57K, decreased the minimal inhibitory concentration (MIC) (Etest) to tetracycline to 0.75 μg/ml (compared to 2 μg/ml in the parent strain) and hence resulted in hypersensitivity to tetracycline, most exchanges, including the ones reported previously in resistant isolates (V57L, V57D, and V57I) resulted in slightly increased MICs to tigecycline and tetracycline. The strongest increase was observed for the V57L mutant, with a MIC (Etest) to tigecycline of 0.5 μg/ml (compared to 0.125 μg/ml in the parent strain) and a MIC to tetracycline of 4.0 μg/ml. Nevertheless, none of these exchanges increased the MIC to the extent observed in previously described clinical tigecycline-resistant isolates. We conclude that, next to S10 mutations, additional mutations are necessary in order to reach high-level tigecycline resistance in E. coli. In addition, our data reveal that mutants carrying S10 V57 exchanges or deletion display growth defects and, in most cases, also thermosensitivity. The defects are particularly strong in the V57 deletion mutant, which is additionally cold-sensitive. We hypothesize that the S10 loop tip residue is critical for the correct functioning of S10. Both the S10 flexible loop and tigecycline are in contact with helix h31 of the 16S rRNA. We speculate that exchanges or deletion of V57 alter the positioning of h31, thereby influencing both tigecycline binding and S10 function.
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Affiliation(s)
- Norbert Izghirean
- Diagnostic and Research Center for Molecular BioMedicine, Medical University of Graz, Graz, Austria.,Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Claudia Waidacher
- Diagnostic and Research Center for Molecular BioMedicine, Medical University of Graz, Graz, Austria.,Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Clemens Kittinger
- Diagnostic and Research Center for Molecular BioMedicine, Medical University of Graz, Graz, Austria
| | - Miriam Chyba
- Diagnostic and Research Center for Molecular BioMedicine, Medical University of Graz, Graz, Austria.,Biotech Campus Tulln, University of Applied Sciences Wiener Neustadt, Tulln, Austria
| | - Günther Koraimann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Gernot Zarfel
- Diagnostic and Research Center for Molecular BioMedicine, Medical University of Graz, Graz, Austria
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8
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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9
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Mitterer V, Shayan R, Ferreira-Cerca S, Murat G, Enne T, Rinaldi D, Weigl S, Omanic H, Gleizes PE, Kressler D, Plisson-Chastang C, Pertschy B. Conformational proofreading of distant 40S ribosomal subunit maturation events by a long-range communication mechanism. Nat Commun 2019; 10:2754. [PMID: 31227701 PMCID: PMC6588571 DOI: 10.1038/s41467-019-10678-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 05/23/2019] [Indexed: 12/21/2022] Open
Abstract
Eukaryotic ribosomes are synthesized in a hierarchical process driven by a plethora of assembly factors, but how maturation events at physically distant sites on pre-ribosomes are coordinated is poorly understood. Using functional analyses and cryo-EM, we show that ribosomal protein Rps20 orchestrates communication between two multi-step maturation events across the pre-40S subunit. Our study reveals that during pre-40S maturation, formation of essential contacts between Rps20 and Rps3 permits assembly factor Ltv1 to recruit the Hrr25 kinase, thereby promoting Ltv1 phosphorylation. In parallel, a deeply buried Rps20 loop reaches to the opposite pre-40S side, where it stimulates Rio2 ATPase activity. Both cascades converge to the final maturation steps releasing Rio2 and phosphorylated Ltv1. We propose that conformational proofreading exerted via Rps20 constitutes a checkpoint permitting assembly factor release and progression of pre-40S maturation only after completion of all earlier maturation steps. The biogenesis of eukaryotic ribosomes is a multi-step process involving the action of more than 200 different ribosome assembly factors. Here the authors show that Rps20 acts as a conduit to coordinate maturation steps across the head domain of the nascent small ribosomal subunit.
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Affiliation(s)
- Valentin Mitterer
- Institute for Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010, Graz, Austria.,Biochemistry Centre, University of Heidelberg, 69120, Heidelberg, Germany
| | - Ramtin Shayan
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062, Toulouse Cedex, France
| | - Sébastien Ferreira-Cerca
- Biochemistry III - Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
| | - Guillaume Murat
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700, Fribourg, Switzerland
| | - Tanja Enne
- Institute for Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010, Graz, Austria
| | - Dana Rinaldi
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062, Toulouse Cedex, France
| | - Sarah Weigl
- Institute for Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010, Graz, Austria
| | - Hajrija Omanic
- Institute for Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010, Graz, Austria
| | - Pierre-Emmanuel Gleizes
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062, Toulouse Cedex, France
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700, Fribourg, Switzerland.
| | - Celia Plisson-Chastang
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062, Toulouse Cedex, France.
| | - Brigitte Pertschy
- Institute for Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010, Graz, Austria.
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10
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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] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [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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11
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Gantenbein N, Bernhart E, Anders I, Golob-Schwarzl N, Krassnig S, Wodlej C, Brcic L, Lindenmann J, Fink-Neuboeck N, Gollowitsch F, Stacher-Priehse E, Asslaber M, Gogg-Kamerer M, Rolff J, Hoffmann J, Silvestri A, Regenbrecht C, Reinhard C, Pehserl AM, Pichler M, Sokolova O, Naumann M, Mitterer V, Pertschy B, Bergler H, Popper H, Sattler W, Haybaeck J. Influence of eukaryotic translation initiation factor 6 on non-small cell lung cancer development and progression. Eur J Cancer 2018; 101:165-180. [PMID: 30077122 DOI: 10.1016/j.ejca.2018.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/22/2018] [Accepted: 07/02/2018] [Indexed: 12/12/2022]
Abstract
Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. Dysregulation of protein synthesis plays a major role in carcinogenesis, a process regulated at multiple levels, including translation of mRNA into proteins. Ribosome assembly requires correct association of ribosome subunits, which is ensured by eukaryotic translation initiation factors (eIFs). eIFs have become targets in cancer therapy studies, and promising data on eIF6 in various cancer entities have been reported. Therefore, we hypothesised that eIF6 represents a crossroad for pulmonary carcinogenesis. High levels of eIF6 are associated with shorter patient overall survival in adenocarcinoma (ADC), but not in squamous cell carcinoma (SQC) of the lung. We demonstrate significantly higher protein expression of eIF6 in ADC and SQC than in healthy lung tissue based on immunohistochemical data from tissue microarrays (TMAs) and on fresh frozen lung tissue. Depletion of eIF6 in ADC and SQC lung cancer cell lines inhibited cell proliferation and induced apoptosis. Knockdown of eIF6 led to pre-rRNA processing and ribosomal 60S maturation defects. Our data indicate that eIF6 is upregulated in NSCLC, suggesting an important contribution of eIF6 to the development and progression of NSCLC and a potential for new treatment strategies against NSCLC.
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Affiliation(s)
- Nadine Gantenbein
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria; Center for Biomarker Research in Medicine, Stiftingtalstrasse 5, 8010 Graz, Austria
| | - Eva Bernhart
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Ines Anders
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Nicole Golob-Schwarzl
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria; Center for Biomarker Research in Medicine, Stiftingtalstrasse 5, 8010 Graz, Austria
| | - Stefanie Krassnig
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Christina Wodlej
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria; Center for Biomarker Research in Medicine, Stiftingtalstrasse 5, 8010 Graz, Austria
| | - Luka Brcic
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Joerg Lindenmann
- Division of Thoracic and Hyperbaric Surgery, Medical University of Graz, Auenbruggerplatz 29, 8036 Graz, Austria
| | - Nicole Fink-Neuboeck
- Division of Thoracic and Hyperbaric Surgery, Medical University of Graz, Auenbruggerplatz 29, 8036 Graz, Austria
| | - Franz Gollowitsch
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Elvira Stacher-Priehse
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Martin Asslaber
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Margit Gogg-Kamerer
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Jana Rolff
- Experimental Pharmacology & Oncology Berlin GmbH-Berlin-Buch, Robert-Rössle-Str. 10, 13125 Berlin-Buch, Germany
| | - Jens Hoffmann
- Experimental Pharmacology & Oncology Berlin GmbH-Berlin-Buch, Robert-Rössle-Str. 10, 13125 Berlin-Buch, Germany
| | - Alessandra Silvestri
- Cpo - Cellular Phenomics & Oncology Berlin-Buch GmbH, Robert-Rössle-Str. 10, 13125 Berlin-Buch, Germany
| | - Christian Regenbrecht
- Cpo - Cellular Phenomics & Oncology Berlin-Buch GmbH, Robert-Rössle-Str. 10, 13125 Berlin-Buch, Germany
| | - Christoph Reinhard
- Eli Lilly & Company, Lilly Corporate Center, 46285 Indiana, Indianapolis, USA
| | - Anna-Maria Pehserl
- Division of Oncology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Martin Pichler
- Division of Oncology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Olga Sokolova
- Institute of Experimental Internal Medicine, Otto-von-Guericke-University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany
| | - Michael Naumann
- Institute of Experimental Internal Medicine, Otto-von-Guericke-University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany
| | - Valentin Mitterer
- Institute of Molecular Biosciences, Karl-Franzens-University of Graz, Humboldtstraße 50, 8010 Graz, Austria
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, Karl-Franzens-University of Graz, Humboldtstraße 50, 8010 Graz, Austria
| | - Helmut Bergler
- Institute of Molecular Biosciences, Karl-Franzens-University of Graz, Humboldtstraße 50, 8010 Graz, Austria
| | - Helmut Popper
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Wolfgang Sattler
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Johannes Haybaeck
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria; Center for Biomarker Research in Medicine, Stiftingtalstrasse 5, 8010 Graz, Austria; Department of Pathology, Medical Faculty, Otto-von-Guericke-University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany.
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12
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Zisser G, Ohmayer U, Mauerhofer C, Mitterer V, Klein I, Rechberger GN, Wolinski H, Prattes M, Pertschy B, Milkereit P, Bergler H. Viewing pre-60S maturation at a minute's timescale. Nucleic Acids Res 2018; 46:3140-3151. [PMID: 29294095 PMCID: PMC5888160 DOI: 10.1093/nar/gkx1293] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/30/2017] [Accepted: 12/18/2017] [Indexed: 12/03/2022] Open
Abstract
The formation of ribosomal subunits is a highly dynamic process that is initiated in the nucleus and involves more than 200 trans-acting factors, some of which accompany the pre-ribosomes into the cytoplasm and have to be recycled into the nucleus. The inhibitor diazaborine prevents cytoplasmic release and recycling of shuttling pre-60S maturation factors by inhibiting the AAA-ATPase Drg1. The failure to recycle these proteins results in their depletion in the nucleolus and halts the pathway at an early maturation step. Here, we made use of the fast onset of inhibition by diazaborine to chase the maturation path in real-time from 27SA2 pre-rRNA containing pre-ribosomes localized in the nucleolus up to nearly mature 60S subunits shortly after their export into the cytoplasm. This allows for the first time to put protein assembly and disassembly reactions as well as pre-rRNA processing into a chronological context unraveling temporal and functional linkages during ribosome maturation.
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Affiliation(s)
- Gertrude Zisser
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
| | - Uli Ohmayer
- Lehrstuhl Biochemie III, University Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Christina Mauerhofer
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
| | - Valentin Mitterer
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
| | - Isabella Klein
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
| | - Gerald N Rechberger
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
- Omics Center Graz, BioTechMed-Graz, A-8010 Graz, Austria
| | - Heimo Wolinski
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
- BioTechMed-Graz, A-8010 Graz, Austria
| | - Michael Prattes
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
- BioTechMed-Graz, A-8010 Graz, Austria
| | - Philipp Milkereit
- Lehrstuhl Biochemie III, University Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Helmut Bergler
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
- BioTechMed-Graz, A-8010 Graz, Austria
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13
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Sprenger H, Kienesberger S, Pertschy B, Pöltl L, Konrad B, Bhutada P, Vorkapic D, Atzmüller D, Feist F, Högenauer C, Gorkiewicz G, Zechner EL. Fic Proteins of Campylobacter fetus subsp. venerealis Form a Network of Functional Toxin-Antitoxin Systems. Front Microbiol 2017; 8:1965. [PMID: 29089929 PMCID: PMC5651007 DOI: 10.3389/fmicb.2017.01965] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 09/25/2017] [Indexed: 01/02/2023] Open
Abstract
Enzymes containing the FIC (filamentation induced by cyclic AMP) domain catalyze post-translational modifications of target proteins. In bacteria the activity of some Fic proteins resembles classical toxin–antitoxin (TA) systems. An excess of toxin over neutralizing antitoxin can enable bacteria to survive some stress conditions by slowing metabolic processes and promoting dormancy. The cell can return to normal growth when sufficient antitoxin is present to block toxin activity. Fic genes of the human and animal pathogen Campylobacter fetus are significantly associated with just one subspecies, which is specifically adapted to the urogenital tract. Here, we demonstrate that the fic genes of virulent isolate C. fetus subsp. venerealis 84-112 form multiple TA systems. Expression of the toxins in Escherichia coli caused filamentation and growth inhibition phenotypes reversible by concomitant antitoxin expression. Key active site residues involved in adenylylation by Fic proteins are conserved in Fic1, Fic3 and Fic4, but degenerated in Fic2. We show that both Fic3 and the non-canonical Fic2 disrupt assembly and function of E. coli ribosomes when expressed independently of a trans-acting antitoxin. Toxicity of the Fic proteins is controlled by different mechanisms. The first involves intramolecular regulation by an inhibitory helix typical for Fic proteins. The second is an unusual neutralization by heterologous Fic–Fic protein interactions. Moreover, a small interacting antitoxin called Fic inhibitory protein 3, which appears unrelated to known Fic antitoxins, has the novel capacity to bind and neutralize Fic toxins encoded in cis and at distant sites. These findings reveal a remarkable system of functional crosstalk occurring between Fic proteins expressed from chromosomal and extrachromosomal modules. Conservation of fic genes in other bacteria that either inhabit or establish pathology in the urogenital tract of humans and animals underscores the significance of these factors for niche-specific adaptation and virulence.
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Affiliation(s)
- Hanna Sprenger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,Institute of Pathology, Medical University of Graz, Graz, Austria.,Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Sabine Kienesberger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,Institute of Pathology, Medical University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Lisa Pöltl
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Bettina Konrad
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Priya Bhutada
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Dina Vorkapic
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Denise Atzmüller
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Florian Feist
- Vehicle Safety Institute, Graz University of Technology, Graz, Austria
| | - Christoph Högenauer
- Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Gregor Gorkiewicz
- Institute of Pathology, Medical University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Ellen L Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
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14
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Abstract
The biogenesis of ribosomes is a central process in all dividing cells. Eukaryotic ribosomes are composed of a large 60S and a small 40S subunit, each comprising a complex assembly of ribosomal RNA (rRNA) and ribosomal proteins (r-proteins). The synthesis of these constituents is spatially separated, with r-proteins being produced by translation in the cytoplasm, while rRNA is generated by transcription in the nucleus. Hence, the arrangement of r-proteins and rRNA into large ribonucleoprotein complexes requires dedicated mechanisms ensuring their encounter in the same compartment. To this end, r-proteins need to be safely delivered to the nucleus where they assemble with the rRNA. Beyond these initial challenges, the synthesis of ribosomes does not merely comprise the joining of r-proteins with rRNA, but occurs in a complex assembly line involving multiple maturation steps, including the processing and folding of rRNA. R-proteins usually have composite rRNA binding sites, with several different rRNA helices contributing to the full interaction. Not all of these interaction sites may already be accessible at the point when an r-protein is incorporated, necessitating that some of the r-protein-rRNA contacts are formed at later maturation stages. In our two recent studies, we investigated the ribosome assembly path of r-proteins in the yeast Saccharomyces cerevisiae using the small subunit r-protein S3 (Rps3) as a model. Our studies revealed intricate mechanisms to protect the protein, transport it into the nucleus, integrate it into pre-ribosomal precursor particles and promote its final stable association with 40S subunits.
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Affiliation(s)
- Brigitte Pertschy
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
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15
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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16
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Mitterer V, Murat G, Réty S, Blaud M, Delbos L, Stanborough T, Bergler H, Leulliot N, Kressler D, Pertschy B. Sequential domain assembly of ribosomal protein S3 drives 40S subunit maturation. Nat Commun 2016; 7:10336. [PMID: 26831757 PMCID: PMC4740875 DOI: 10.1038/ncomms10336] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 11/29/2015] [Indexed: 11/25/2022] Open
Abstract
Eukaryotic ribosomes assemble by association of ribosomal RNA with ribosomal proteins into nuclear precursor particles, which undergo a complex maturation pathway coordinated by non-ribosomal assembly factors. Here, we provide functional insights into how successive structural re-arrangements in ribosomal protein S3 promote maturation of the 40S ribosomal subunit. We show that S3 dimerizes and is imported into the nucleus with its N-domain in a rotated conformation and associated with the chaperone Yar1. Initial assembly of S3 with 40S precursors occurs via its C-domain, while the N-domain protrudes from the 40S surface. Yar1 is replaced by the assembly factor Ltv1, thereby fixing the S3 N-domain in the rotated orientation and preventing its 40S association. Finally, Ltv1 release, triggered by phosphorylation, and flipping of the S3 N-domain into its final position results in the stable integration of S3. Such a stepwise assembly may represent a new paradigm for the incorporation of ribosomal proteins. Ribosome biogenesis involves the hierarchical assembly of several proteins and RNA components. Here the authors describe a mechanism for ribosomal protein S3 incorporation into 40S ribosomal subunits that involves S3 dimerization and stepwise incorporation of two distinct S3 interaction domains coupled to release of ribosomal maturation factors.
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Affiliation(s)
- Valentin Mitterer
- Institut für Molekulare Biowissenschaften, Universität Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Guillaume Murat
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Stéphane Réty
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, 75006 Paris, France
| | - Magali Blaud
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, 75006 Paris, France
| | - Lila Delbos
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, 75006 Paris, France
| | - Tamsyn Stanborough
- Institut für Molekulare Biowissenschaften, Universität Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Helmut Bergler
- Institut für Molekulare Biowissenschaften, Universität Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Nicolas Leulliot
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, 75006 Paris, France
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Brigitte Pertschy
- Institut für Molekulare Biowissenschaften, Universität Graz, Humboldtstrasse 50, 8010 Graz, Austria
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17
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Loibl M, Klein I, Prattes M, Schmidt C, Kappel L, Zisser G, Gungl A, Krieger E, Pertschy B, Bergler H. The drug diazaborine blocks ribosome biogenesis by inhibiting the AAA-ATPase Drg1. J Biol Chem 2014; 289:3913-22. [PMID: 24371142 PMCID: PMC3924260 DOI: 10.1074/jbc.m113.536110] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 12/17/2013] [Indexed: 01/23/2023] Open
Abstract
The drug diazaborine is the only known inhibitor of ribosome biogenesis and specifically blocks large subunit formation in eukaryotic cells. However, the target of this drug and the mechanism of inhibition were unknown. Here we identify the AAA-ATPase Drg1 as a target of diazaborine. Inhibitor binding into the second AAA domain of Drg1 requires ATP loading and results in inhibition of ATP hydrolysis in this site. As a consequence the physiological activity of Drg1, i.e. the release of Rlp24 from pre-60S particles, is blocked, and further progression of cytoplasmic preribosome maturation is prevented. Our results identify the first target of an inhibitor of ribosome biogenesis and provide the mechanism of inhibition of a key step in large ribosomal subunit formation.
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Affiliation(s)
- Mathias Loibl
- From the Institut für Molekulare Biowissenschaften, Karl-Franzens-Universität Graz, A-8010 Graz, Austria and
| | - Isabella Klein
- From the Institut für Molekulare Biowissenschaften, Karl-Franzens-Universität Graz, A-8010 Graz, Austria and
| | - Michael Prattes
- From the Institut für Molekulare Biowissenschaften, Karl-Franzens-Universität Graz, A-8010 Graz, Austria and
| | - Claudia Schmidt
- From the Institut für Molekulare Biowissenschaften, Karl-Franzens-Universität Graz, A-8010 Graz, Austria and
| | - Lisa Kappel
- From the Institut für Molekulare Biowissenschaften, Karl-Franzens-Universität Graz, A-8010 Graz, Austria and
| | - Gertrude Zisser
- From the Institut für Molekulare Biowissenschaften, Karl-Franzens-Universität Graz, A-8010 Graz, Austria and
| | - Anna Gungl
- From the Institut für Molekulare Biowissenschaften, Karl-Franzens-Universität Graz, A-8010 Graz, Austria and
| | - Elmar Krieger
- Centre for Molecular and Biomolecular Informatics 260, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, The Netherlands
| | - Brigitte Pertschy
- From the Institut für Molekulare Biowissenschaften, Karl-Franzens-Universität Graz, A-8010 Graz, Austria and
| | - Helmut Bergler
- From the Institut für Molekulare Biowissenschaften, Karl-Franzens-Universität Graz, A-8010 Graz, Austria and
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18
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Stanborough T, Niederhauser J, Koch B, Bergler H, Pertschy B. Ribosomal protein S3 interacts with the NF-κB inhibitor IκBα. FEBS Lett 2014; 588:659-64. [PMID: 24457201 DOI: 10.1016/j.febslet.2013.12.034] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 12/03/2013] [Accepted: 12/24/2013] [Indexed: 02/01/2023]
Abstract
Ribosomal protein S3 (RPS3) is part of nuclear, transcriptionally active and cytoplasmic inhibitory complexes containing NF-κB variant p65. We show that in resting HEK293 cells, RPS3 interacts with NF-κB inhibitor IκBα. In contrast, efficient co-precipitation of p65 with RPS3 was only achieved in the presence of ectopic IκBα. In addition, a strong in vitro interaction was observed between RPS3 and IκBα, while binding between RPS3 and p65 was very weak. Furthermore, IκBα facilitated the reconstitution of p65 and RPS3 into one complex in vitro. Our results suggest that IκBα sequesters not only p65 but also RPS3 in the cytoplasm. This would ensure maintenance of an RPS3 pool for the NF-κB pathway as well as equimolar release of RPS3 and p65 upon stimulation.
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Affiliation(s)
- Tamsyn Stanborough
- Institut für Molekulare Biowissenschaften, Universität Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Johannes Niederhauser
- Institut für Molekulare Biowissenschaften, Universität Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Barbara Koch
- Institut für Molekulare Biowissenschaften, Universität Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Helmut Bergler
- Institut für Molekulare Biowissenschaften, Universität Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Brigitte Pertschy
- Institut für Molekulare Biowissenschaften, Universität Graz, Humboldtstrasse 50, 8010 Graz, Austria.
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19
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Reinthaler FF, Galler H, Feierl G, Haas D, Leitner E, Mascher F, Melkes A, Posch J, Pertschy B, Winter I, Himmel W, Marth E, Zarfel G. Resistance patterns of Escherichia coli isolated from sewage sludge in comparison with those isolated from human patients in 2000 and 2009. J Water Health 2013; 11:13-20. [PMID: 23428545 DOI: 10.2166/wh.2012.207] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
For some time now, antibiotic-resistant bacterial strains have been found in the human population, in foods, in livestock and wild animals, as well as in surface waters. The entry of antibiotics and resistant bacterial strains into the environment plays an important role in the spread of antibiotic resistance. The goal of the present study was to monitor the entry of antibiotic resistances into the environment through the contamination of wastewater. To assess the extent of transmission of antibiotic resistances from human sources into the environment, the resistance patterns of Escherichia coli strains isolated from human patients have been compared to those found in strains isolated from sewage sludge. Our results may indicate if resistances to particular antibiotics are more prone than others to spread into the environment. To monitor the increase of specific resistances over time, samples taken in the years 2000 and 2009 were analysed. Our study shows that for some antibiotics a parallel development of resistance patterns has taken place in both patient and environmental samples over time. For other sets of antibiotics, independent developments have occurred in the samples. A clear increase of multi-resistant E. coli strains over time was observed in samples from both sources.
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20
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Kappel L, Loibl M, Zisser G, Klein I, Fruhmann G, Gruber C, Unterweger S, Rechberger G, Pertschy B, Bergler H. Rlp24 activates the AAA-ATPase Drg1 to initiate cytoplasmic pre-60S maturation. ACTA ACUST UNITED AC 2013. [PMID: 23185031 PMCID: PMC3514788 DOI: 10.1083/jcb.201205021] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Formation of eukaryotic ribosomes is driven by energy-consuming enzymes. The AAA-ATPase Drg1 is essential for the release of several shuttling proteins from cytoplasmic pre-60S particles and the loading of late joining proteins. However, its exact role in ribosome biogenesis has been unknown. Here we show that the shuttling protein Rlp24 recruited Drg1 to pre-60S particles and stimulated its ATPase activity. ATP hydrolysis in the second AAA domain of Drg1 was required to release shuttling proteins. In vitro, Drg1 specifically and exclusively extracted Rlp24 from purified pre-60S particles. Rlp24 release required ATP and was promoted by the interaction of Drg1 with the nucleoporin Nup116. Subsequent ATP hydrolysis in the first AAA domain dissociated Drg1 from Rlp24, liberating both proteins for consecutive cycles of activity. Our results show that release of Rlp24 by Drg1 defines a key event in large subunit formation that is a prerequisite for progression of cytoplasmic pre-60S maturation.
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Affiliation(s)
- Lisa Kappel
- Institut für Molekulare Biowissenschaften, Karl-Franzens Universität Graz, A-8010 Graz, Austria
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21
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Koch B, Mitterer V, Niederhauser J, Stanborough T, Murat G, Rechberger G, Bergler H, Kressler D, Pertschy B. Yar1 protects the ribosomal protein Rps3 from aggregation. J Biol Chem 2012; 287:21806-15. [PMID: 22570489 DOI: 10.1074/jbc.m112.365791] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
2000 ribosomes have to be synthesized in yeast every minute. Therefore the fast production of ribosomal proteins, their efficient delivery to the nucleus and correct incorporation into ribosomal subunits are prerequisites for optimal growth rates. Here, we report that the ankyrin repeat protein Yar1 directly interacts with the small ribosomal subunit protein Rps3 and accompanies newly synthesized Rps3 from the cytoplasm into the nucleus where Rps3 is assembled into pre-ribosomal subunits. A yar1 deletion strain displays a similar phenotype as an rps3 mutant strain, showing an accumulation of 20S pre-rRNA and a 40S export defect. The combination of an rps3 mutation with a yar1 deletion leads to an enhancement of these phenotypes, while increased expression of RPS3 suppresses the defects of a yar1 deletion strain. We further show that Yar1 protects Rps3 from aggregation in vitro and increases its solubility in vivo. Our data suggest that Yar1 is a specific chaperone for Rps3, which serves to keep Rps3 soluble until its incorporation into the pre-ribosome.
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Affiliation(s)
- Barbara Koch
- Institut für Molekulare Biowissenschaften, Universität Graz, Humboldtstrasse 50, A-8010 Graz, Austria
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22
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Bassler J, Kallas M, Pertschy B, Ulbrich C, Thoms M, Hurt E. The AAA-ATPase Rea1 drives removal of biogenesis factors during multiple stages of 60S ribosome assembly. Mol Cell 2010; 38:712-21. [PMID: 20542003 DOI: 10.1016/j.molcel.2010.05.024] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 03/17/2010] [Accepted: 04/21/2010] [Indexed: 12/18/2022]
Abstract
The AAA(+)-ATPase Rea1 removes the ribosome biogenesis factor Rsa4 from pre-60S ribosomal subunits in the nucleoplasm to drive nuclear export of the subunit. To do this, Rea1 utilizes a MIDAS domain to bind a conserved motif in Rsa4. Here, we show that the Rea1 MIDAS domain binds another pre-60S factor, Ytm1, via a related motif. In vivo Rea1 contacts Ytm1 before it contacts Rsa4, and its interaction with Ytm1 coincides with the exit of early pre-60S particles from the nucleolus to the nucleoplasm. In vitro, Rea1's ATPase activity triggers removal of the conserved nucleolar Ytm1-Erb1-Nop7 subcomplex from isolated early pre-60S particle. We suggest that the Rea1 AAA(+)-ATPase functions at successive maturation steps to remove ribosomal factors at critical transition points, first driving the exit of early pre-60S particles from the nucleolus and then driving late pre-60S particles from the nucleus.
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Affiliation(s)
- Jochen Bassler
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
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23
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Pertschy B, Schneider C, Gnädig M, Schäfer T, Tollervey D, Hurt E. RNA helicase Prp43 and its co-factor Pfa1 promote 20 to 18 S rRNA processing catalyzed by the endonuclease Nob1. J Biol Chem 2009; 284:35079-91. [PMID: 19801658 PMCID: PMC2787369 DOI: 10.1074/jbc.m109.040774] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 09/29/2009] [Indexed: 11/06/2022] Open
Abstract
Many RNA nucleases and helicases participate in ribosome biogenesis, but how they cooperate with each other is largely unknown. Here we report that in vivo cleavage of the yeast pre-rRNA at site D, the 3'-end of the 18 S rRNA, requires functional interactions between PIN (PilT N terminus) domain protein Nob1 and the DEAH box RNA helicase Prp43. Nob1 showed specific cleavage on a D-site substrate analogue in vitro, which was abolished by mutations in the Nob1 PIN domain or the RNA substrate. Genetic analyses linked Nob1 to the late pre-40 S-associated factor Ltv1, the RNA helicase Prp43, and its cofactor Pfa1. In strains lacking Ltv1, mutation of Prp43 or Pfa1 led to a striking accumulation of 20 S pre-rRNA in the cytoplasm due to inhibition of site D cleavage. This phenotype was suppressed by increased dosage of wild-type Nob1 but not by Nob1 variants mutated in the catalytic site. In ltv1/pfa1 mutants the 20 S pre-rRNA was susceptible to 3' to 5' degradation by the cytoplasmic exosome. This degraded into the 3' region of the 18 S rRNA, strongly indicating that the preribosomes are structurally defective.
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Affiliation(s)
- Brigitte Pertschy
- From the Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany and
| | - Claudia Schneider
- the Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Marén Gnädig
- From the Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany and
| | - Thorsten Schäfer
- From the Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany and
| | - David Tollervey
- the Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Ed Hurt
- From the Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany and
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24
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Kressler D, Roser D, Pertschy B, Hurt E. The AAA ATPase Rix7 powers progression of ribosome biogenesis by stripping Nsa1 from pre-60S particles. ACTA ACUST UNITED AC 2008; 181:935-44. [PMID: 18559667 PMCID: PMC2426938 DOI: 10.1083/jcb.200801181] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Ribosome biogenesis takes place successively in the nucleolar, nucleoplasmic, and cytoplasmic compartments. Numerous nonribosomal factors transiently associate with the nascent ribosomes, but the mechanisms driving ribosome formation are mostly unknown. Here, we show that an energy-consuming enzyme, the AAA-type (ATPases associated with various cellular activities) ATPase Rix7, restructures a novel pre-60S particle at the transition from the nucleolus to nucleoplasm. Rix7 interacts genetically with Nsa1 and is targeted to the Nsa1-defined preribosomal particle. In vivo, Nsa1 cannot dissociate from pre-60S particles in rix7 mutants, causing nucleolar Nsa1 to escape to the cytoplasm, where it remains associated with aberrant 60S subunits. Altogether, our data suggest that Rix7 is required for the release of Nsa1 from a discrete preribosomal particle, thereby triggering the progression of 60S ribosome biogenesis.
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Affiliation(s)
- Dieter Kressler
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
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25
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Pertschy B, Saveanu C, Zisser G, Lebreton A, Tengg M, Jacquier A, Liebminger E, Nobis B, Kappel L, van der Klei I, Högenauer G, Fromont-Racine M, Bergler H. Cytoplasmic recycling of 60S preribosomal factors depends on the AAA protein Drg1. Mol Cell Biol 2007; 27:6581-92. [PMID: 17646390 PMCID: PMC2099225 DOI: 10.1128/mcb.00668-07] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Allelic forms of DRG1/AFG2 confer resistance to the drug diazaborine, an inhibitor of ribosome biogenesis in Saccharomyces cerevisiae. Our results show that the AAA-ATPase Drg1 is essential for 60S maturation and associates with 60S precursor particles in the cytoplasm. Functional inactivation of Drg1 leads to an increased cytoplasmic localization of shuttling pre-60S maturation factors like Rlp24, Arx1, and Tif6. Surprisingly, Nog1, a nuclear pre-60S factor, was also relocalized to the cytoplasm under these conditions, suggesting that it is a previously unsuspected shuttling preribosomal factor that is exported with the precursor particles and very rapidly reimported. Proteins that became cytoplasmic under drg1 mutant conditions were blocked on pre-60S particles at a step that precedes the association of Rei1, a later-acting preribosomal factor. A similar cytoplasmic accumulation of Nog1 and Rlp24 in pre-60S-bound form could be seen after overexpression of a dominant-negative Drg1 variant mutated in the D2 ATPase domain. We conclude that the ATPase activity of Drg1 is required for the release of shuttling proteins from the pre-60S particles shortly after their nuclear export. This early cytoplasmic release reaction defines a novel step in eukaryotic ribosome maturation.
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Affiliation(s)
- Brigitte Pertschy
- Institut für Molekulare Biowissenschaften. Karl-Franzens Universität Graz, Universitätsplatz 2, A-8010, Graz, Austria
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26
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Pertschy B, Zisser G, Schein H, Köffel R, Rauch G, Grillitsch K, Morgenstern C, Durchschlag M, Högenauer G, Bergler H. Diazaborine treatment of yeast cells inhibits maturation of the 60S ribosomal subunit. Mol Cell Biol 2004; 24:6476-87. [PMID: 15226447 PMCID: PMC434233 DOI: 10.1128/mcb.24.14.6476-6487.2004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2004] [Revised: 03/08/2004] [Accepted: 04/19/2004] [Indexed: 11/20/2022] Open
Abstract
Diazaborine treatment of yeast cells was shown previously to cause accumulation of aberrant, 3'-elongated mRNAs. Here we demonstrate that the drug inhibits maturation of rRNAs for the large ribosomal subunit. Pulse-chase analyses showed that the processing of the 27S pre-rRNA to consecutive species was blocked in the drug-treated wild-type strain. The steady-state level of the 7S pre-rRNA was clearly reduced after short-term treatment with the inhibitor. At the same time an increase of the 35S pre-rRNA was observed. Longer incubation with the inhibitor resulted in a decrease of the 27S precursor. Primer extension assays showed that an early step in 27S pre-rRNA processing is inhibited, which results in an accumulation of the 27SA2 pre-rRNA and a strong decrease of the 27SA3, 27SB1L, and 27SB1S precursors. The rRNA processing pattern observed after diazaborine treatment resembles that reported after depletion of the RNA binding protein Nop4p/Nop77p. This protein is essential for correct pre-27S rRNA processing. Using a green fluorescent protein-Nop4 fusion, we found that diazaborine treatment causes, within minutes, a rapid redistribution of the protein from the nucleolus to the periphery of the nucleus, which provides a possible explanation for the effect of diazaborine on rRNA processing.
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Affiliation(s)
- Brigitte Pertschy
- Institut für Molekularbiologie, Biochemie und Mikrobiologie, Karl-Franzens-Universität Graz, Austria
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