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Doron‐Mandel E, Koppel I, Abraham O, Rishal I, Smith TP, Buchanan CN, Sahoo PK, Kadlec J, Oses‐Prieto JA, Kawaguchi R, Alber S, Zahavi EE, Di Matteo P, Di Pizio A, Song D, Okladnikov N, Gordon D, Ben‐Dor S, Haffner‐Krausz R, Coppola G, Burlingame AL, Jungwirth P, Twiss JL, Fainzilber M. The glycine arginine-rich domain of the RNA-binding protein nucleolin regulates its subcellular localization. EMBO J 2021; 40:e107158. [PMID: 34515347 PMCID: PMC8521312 DOI: 10.15252/embj.2020107158] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 07/29/2021] [Accepted: 08/03/2021] [Indexed: 12/31/2022] Open
Abstract
Nucleolin is a multifunctional RNA Binding Protein (RBP) with diverse subcellular localizations, including the nucleolus in all eukaryotic cells, the plasma membrane in tumor cells, and the axon in neurons. Here we show that the glycine arginine rich (GAR) domain of nucleolin drives subcellular localization via protein-protein interactions with a kinesin light chain. In addition, GAR sequences mediate plasma membrane interactions of nucleolin. Both these modalities are in addition to the already reported involvement of the GAR domain in liquid-liquid phase separation in the nucleolus. Nucleolin transport to axons requires the GAR domain, and heterozygous GAR deletion mice reveal reduced axonal localization of nucleolin cargo mRNAs and enhanced sensory neuron growth. Thus, the GAR domain governs axonal transport of a growth controlling RNA-RBP complex in neurons, and is a versatile localization determinant for different subcellular compartments. Localization determination by GAR domains may explain why GAR mutants in diverse RBPs are associated with neurodegenerative disease.
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Affiliation(s)
- Ella Doron‐Mandel
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
- Present address:
Department of Biological SciencesColumbia UniversityNew YorkNYUSA
| | - Indrek Koppel
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
- Present address:
Department of Chemistry and BiotechnologyTallinn University of TechnologyTallinnEstonia
| | - Ofri Abraham
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
| | - Ida Rishal
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
| | - Terika P Smith
- Department of Biological SciencesUniversity of South CarolinaColumbiaSCUSA
| | | | - Pabitra K Sahoo
- Department of Biological SciencesUniversity of South CarolinaColumbiaSCUSA
| | - Jan Kadlec
- Institute of Organic Chemistry and BiochemistryCzech Academy of SciencesPragueCzech Republic
| | - Juan A Oses‐Prieto
- Department of Pharmaceutical ChemistryUniversity of California San FranciscoSan FranciscoCAUSA
| | - Riki Kawaguchi
- Departments of Psychiatry and NeurologySemel Institute for Neuroscience and Human BehaviorUniversity of California Los AngelesLos AngelesCAUSA
| | - Stefanie Alber
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
| | - Eitan Erez Zahavi
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
| | - Pierluigi Di Matteo
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
| | - Agostina Di Pizio
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
| | - Didi‐Andreas Song
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
| | - Nataliya Okladnikov
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
| | - Dalia Gordon
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
| | - Shifra Ben‐Dor
- Bioinformatics UnitLife Sciences Core FacilitiesWeizmann Institute of ScienceRehovotIsrael
| | | | - Giovanni Coppola
- Departments of Psychiatry and NeurologySemel Institute for Neuroscience and Human BehaviorUniversity of California Los AngelesLos AngelesCAUSA
| | - Alma L Burlingame
- Department of Pharmaceutical ChemistryUniversity of California San FranciscoSan FranciscoCAUSA
| | - Pavel Jungwirth
- Institute of Organic Chemistry and BiochemistryCzech Academy of SciencesPragueCzech Republic
| | - Jeffery L Twiss
- Department of Biological SciencesUniversity of South CarolinaColumbiaSCUSA
| | - Mike Fainzilber
- Departments of Biomolecular Sciences and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
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2
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Erdmann PS, Hou Z, Klumpe S, Khavnekar S, Beck F, Wilfling F, Plitzko JM, Baumeister W. In situ cryo-electron tomography reveals gradient organization of ribosome biogenesis in intact nucleoli. Nat Commun 2021; 12:5364. [PMID: 34508074 PMCID: PMC8433212 DOI: 10.1038/s41467-021-25413-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 08/09/2021] [Indexed: 02/08/2023] Open
Abstract
Ribosomes comprise a large (LSU) and a small subunit (SSU) which are synthesized independently in the nucleolus before being exported into the cytoplasm, where they assemble into functional ribosomes. Individual maturation steps have been analyzed in detail using biochemical methods, light microscopy and conventional electron microscopy (EM). In recent years, single particle analysis (SPA) has yielded molecular resolution structures of several pre-ribosomal intermediates. It falls short, however, of revealing the spatiotemporal sequence of ribosome biogenesis in the cellular context. Here, we present our study on native nucleoli in Chlamydomonas reinhardtii, in which we follow the formation of LSU and SSU precursors by in situ cryo-electron tomography (cryo-ET) and subtomogram averaging (STA). By combining both positional and molecular data, we reveal gradients of ribosome maturation within the granular component (GC), offering a new perspective on how the liquid-liquid-phase separation of the nucleolus supports ribosome biogenesis.
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Affiliation(s)
- Philipp S Erdmann
- Max Planck Institute of Biochemistry, Martinsried, Germany.
- Fondazione Human Technopole, Milano, Italy.
| | - Zhen Hou
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Sven Klumpe
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | | | - Florian Beck
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Florian Wilfling
- Max Planck Institute of Biochemistry, Martinsried, Germany
- Max Planck Institute of Biophysics, Frankfurt, Germany
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3
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Hoencamp C, Dudchenko O, Elbatsh AMO, Brahmachari S, Raaijmakers JA, van Schaik T, Sedeño Cacciatore Á, Contessoto VG, van Heesbeen RGHP, van den Broek B, Mhaskar AN, Teunissen H, St Hilaire BG, Weisz D, Omer AD, Pham M, Colaric Z, Yang Z, Rao SSP, Mitra N, Lui C, Yao W, Khan R, Moroz LL, Kohn A, St Leger J, Mena A, Holcroft K, Gambetta MC, Lim F, Farley E, Stein N, Haddad A, Chauss D, Mutlu AS, Wang MC, Young ND, Hildebrandt E, Cheng HH, Knight CJ, Burnham TLU, Hovel KA, Beel AJ, Mattei PJ, Kornberg RD, Warren WC, Cary G, Gómez-Skarmeta JL, Hinman V, Lindblad-Toh K, Di Palma F, Maeshima K, Multani AS, Pathak S, Nel-Themaat L, Behringer RR, Kaur P, Medema RH, van Steensel B, de Wit E, Onuchic JN, Di Pierro M, Lieberman Aiden E, Rowland BD. 3D genomics across the tree of life reveals condensin II as a determinant of architecture type. Science 2021; 372:984-989. [PMID: 34045355 PMCID: PMC8172041 DOI: 10.1126/science.abe2218] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [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: 08/19/2020] [Accepted: 04/16/2021] [Indexed: 01/01/2023]
Abstract
We investigated genome folding across the eukaryotic tree of life. We find two types of three-dimensional (3D) genome architectures at the chromosome scale. Each type appears and disappears repeatedly during eukaryotic evolution. The type of genome architecture that an organism exhibits correlates with the absence of condensin II subunits. Moreover, condensin II depletion converts the architecture of the human genome to a state resembling that seen in organisms such as fungi or mosquitoes. In this state, centromeres cluster together at nucleoli, and heterochromatin domains merge. We propose a physical model in which lengthwise compaction of chromosomes by condensin II during mitosis determines chromosome-scale genome architecture, with effects that are retained during the subsequent interphase. This mechanism likely has been conserved since the last common ancestor of all eukaryotes.
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Affiliation(s)
- Claire Hoencamp
- Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Olga Dudchenko
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
| | - Ahmed M O Elbatsh
- Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | | | - Jonne A Raaijmakers
- Division of Cell Biology, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Tom van Schaik
- Division of Gene Regulation, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | | | - Vinícius G Contessoto
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
- Department of Physics, Institute of Biosciences, Letters and Exact Sciences, São Paulo State University (UNESP), São José do Rio Preto - SP, 15054-000, Brazil
| | - Roy G H P van Heesbeen
- Division of Cell Biology, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Bram van den Broek
- BioImaging Facility, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Aditya N Mhaskar
- Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Hans Teunissen
- Division of Gene Regulation, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Brian Glenn St Hilaire
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - David Weisz
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Arina D Omer
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Melanie Pham
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zane Colaric
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zhenzhen Yang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech, Pudong 201210, China
| | - Suhas S P Rao
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Namita Mitra
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christopher Lui
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Weijie Yao
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ruqayya Khan
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Leonid L Moroz
- Whitney Laboratory and Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Andrea Kohn
- Whitney Laboratory and Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Judy St Leger
- Department of Biosciences, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | | | | | | | - Fabian Lim
- Department of Medicine and Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Emma Farley
- Department of Medicine and Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nils Stein
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben), 06466 Seeland, Germany
- Center of Integrated Breeding Research (CiBreed), Department of Crop Sciences, Georg-August-University Göttingen, 37075 Göttingen, Germany
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia
| | - Alexander Haddad
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Daniel Chauss
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ayse Sena Mutlu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meng C Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Neil D Young
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3010, Australia
| | - Evin Hildebrandt
- Avian Diseases and Oncology Laboratory, US Department of Agriculture, Agricultural Research Service, East Lansing, MI 48823, USA
| | - Hans H Cheng
- Avian Diseases and Oncology Laboratory, US Department of Agriculture, Agricultural Research Service, East Lansing, MI 48823, USA
| | | | - Theresa L U Burnham
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, Davis, CA 95616, USA
- Coastal and Marine Institute and Department of Biology, San Diego State University, San Diego, CA 92106, USA
| | - Kevin A Hovel
- Coastal and Marine Institute and Department of Biology, San Diego State University, San Diego, CA 92106, USA
| | - Andrew J Beel
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Pierre-Jean Mattei
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Roger D Kornberg
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Wesley C Warren
- Department of Animal Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Gregory Cary
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - José Luis Gómez-Skarmeta
- Centro Andaluz de Biología del Desarrollo CSIC, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - Veronica Hinman
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Kerstin Lindblad-Toh
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, 751 23 Uppsala, Sweden
| | - Federica Di Palma
- Department of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
| | - Kazuhiro Maeshima
- Genome Dynamics Laboratory, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
- Department of Genetics, Sokendai (Graduate University for Advanced Studies), Mishima, Shizuoka 411-8540, Japan
| | - Asha S Multani
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sen Pathak
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Liesl Nel-Themaat
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Richard R Behringer
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Parwinder Kaur
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia
| | - René H Medema
- Division of Cell Biology, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Bas van Steensel
- Division of Gene Regulation, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Elzo de Wit
- Division of Gene Regulation, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - José N Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
- Departments of Physics and Astronomy, Chemistry, and Biosciences, Rice University, Houston, TX 77005, USA
| | - Michele Di Pierro
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Erez Lieberman Aiden
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech, Pudong 201210, China
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Benjamin D Rowland
- Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands.
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4
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Lacavalla MA, Cisterna B, Zancanaro C, Malatesta M. Ultrastructural immunocytochemistry shows impairment of RNA pathways in skeletal muscle nuclei of old mice: A link to sarcopenia? Eur J Histochem 2021; 65:3229. [PMID: 33764019 PMCID: PMC8033527 DOI: 10.4081/ejh.2021.3229] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 03/15/2021] [Indexed: 12/12/2022] Open
Abstract
During aging, skeletal muscle is affected by sarcopenia, a progressive decline in muscle mass, strength and endurance that leads to loss of function and disability. Cell nucleus dysfunction is a possible factor contributing to sarcopenia because aging-associated alterations in mRNA and rRNA transcription/maturation machinery have been shown in several cell types including muscle cells. In this study, the distribution and density of key molecular factors involved in RNA pathways namely, nuclear actin (a motor protein and regulator of RNA transcription), 5-methyl cytosine (an epigenetic regulator of gene transcription), and ribonuclease A (an RNA degrading enzyme) were compared in different nuclear compartments of late adult and old mice myonuclei by means of ultrastructural immunocytochemistry. In all nuclear compartments, an age-related decrease of nuclear actin suggested altered chromatin structuring and impaired nucleus-to-cytoplasm transport of both mRNA and ribosomal subunits, while a decrease of 5-methyl cytosine and ribonuclease A in the nucleoli of old mice indicated an age-dependent loss of rRNA genes. These findings provide novel experimental evidence that, in the aging skeletal muscle, nuclear RNA pathways undergo impairment, likely hindering protein synthesis and contributing to the onset and progression of sarcopenia.
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Affiliation(s)
| | - Barbara Cisterna
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona.
| | - Carlo Zancanaro
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona.
| | - Manuela Malatesta
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona.
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5
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Houston R, Sekine S, Calderon MJ, Seifuddin F, Wang G, Kawagishi H, Malide DA, Li Y, Gucek M, Pirooznia M, Nelson AJ, Stokes MP, Stewart-Ornstein J, Mullett SJ, Wendell SG, Watkins SC, Finkel T, Sekine Y. Acetylation-mediated remodeling of the nucleolus regulates cellular acetyl-CoA responses. PLoS Biol 2020; 18:e3000981. [PMID: 33253182 PMCID: PMC7728262 DOI: 10.1371/journal.pbio.3000981] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 12/10/2020] [Accepted: 10/29/2020] [Indexed: 12/14/2022] Open
Abstract
The metabolite acetyl-coenzyme A (acetyl-CoA) serves as an essential element for a wide range of cellular functions including adenosine triphosphate (ATP) production, lipid synthesis, and protein acetylation. Intracellular acetyl-CoA concentrations are associated with nutrient availability, but the mechanisms by which a cell responds to fluctuations in acetyl-CoA levels remain elusive. Here, we generate a cell system to selectively manipulate the nucleo-cytoplasmic levels of acetyl-CoA using clustered regularly interspaced short palindromic repeat (CRISPR)-mediated gene editing and acetate supplementation of the culture media. Using this system and quantitative omics analyses, we demonstrate that acetyl-CoA depletion alters the integrity of the nucleolus, impairing ribosomal RNA synthesis and evoking the ribosomal protein-dependent activation of p53. This nucleolar remodeling appears to be mediated through the class IIa histone deacetylases (HDACs). Our findings highlight acetylation-mediated control of the nucleolus as an important hub linking acetyl-CoA fluctuations to cellular stress responses.
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Affiliation(s)
- Ryan Houston
- Aging Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Shiori Sekine
- Aging Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Michael J. Calderon
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Fayaz Seifuddin
- National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, United States of America
| | - Guanghui Wang
- National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, United States of America
| | - Hiroyuki Kawagishi
- National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, United States of America
| | - Daniela A. Malide
- National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, United States of America
| | - Yuesheng Li
- National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, United States of America
| | - Marjan Gucek
- National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, United States of America
| | - Mehdi Pirooznia
- National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, United States of America
| | - Alissa J. Nelson
- Cell Signaling Technology, INC., Danvers, Massachusetts, United States of America
| | - Matthew P. Stokes
- Cell Signaling Technology, INC., Danvers, Massachusetts, United States of America
| | - Jacob Stewart-Ornstein
- Department of Computational and Systems Biology, University of Pittsburgh and Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Steven J. Mullett
- Department of Pharmacology and Chemical Biology, the Health Sciences Metabolomics and Lipidomics Core, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Stacy G. Wendell
- Department of Pharmacology and Chemical Biology, the Health Sciences Metabolomics and Lipidomics Core, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Simon C. Watkins
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Toren Finkel
- Aging Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, United States of America
| | - Yusuke Sekine
- Aging Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, United States of America
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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6
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Kamyshatskaya O, Bondarenko N, Nassonova E, Smirnov A. Polychaos centronucleolus n. sp. - a new terrestrial species of the genus Polychaos (Amoebozoa, Tubulinea) with nontypical nuclear structure. Eur J Protistol 2020; 77:125759. [PMID: 33348278 DOI: 10.1016/j.ejop.2020.125759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/31/2020] [Accepted: 11/11/2020] [Indexed: 11/18/2022]
Abstract
A new species of the "proteus-type" naked amoebae (large cells with discrete tubular pseudopodia) was isolated from tree bark sample of a birch tree in the surrounding of Kislovodsk town, Russia and named Polychaos centronucleolus n. sp. (Amoebozoa, Tubulinea). Amoebae of this species have a filamentous cell coat and a nucleus with a central compact nucleolus. This type of nucleolar organization has not been previously known for the genus Polychaos. A sequence of the 18S rRNA gene of this strain was obtained using whole genome amplification of DNA from the single amoeba cell, followed by NGS sequencing. The analysis of molecular data robustly groups this species with Polychaos annulatum within the family Hartmannellidae. Our results, together with the results of our previous studies, show that the taxonomic assignment of "proteus-type" amoebae species is becoming increasingly complex, and the taxonomic characters that can be used to classify these organisms are becoming more shadowed.
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Affiliation(s)
- Oksana Kamyshatskaya
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, 199034 Universitetskaya nab. 7/9, Saint Petersburg, Russia; Laboratory of Cytology of Unicellular Organisms, Institute of Cytology RAS, Tikhoretsky ave. 4, St. Petersburg 194064, Russia.
| | - Natalya Bondarenko
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, 199034 Universitetskaya nab. 7/9, Saint Petersburg, Russia
| | - Elena Nassonova
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, 199034 Universitetskaya nab. 7/9, Saint Petersburg, Russia; Laboratory of Cytology of Unicellular Organisms, Institute of Cytology RAS, Tikhoretsky ave. 4, St. Petersburg 194064, Russia
| | - Alexey Smirnov
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, 199034 Universitetskaya nab. 7/9, Saint Petersburg, Russia
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7
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Sakamoto Y, Sakamoto T. Toward an understanding of nuclear substructures beyond their classical functions. J Plant Res 2020; 133:447-448. [PMID: 32519078 DOI: 10.1007/s10265-020-01209-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- Yuki Sakamoto
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1‑1 Machikaneyama‑cho, Toyonaka, Osaka, 560-0043, Japan
| | - Takuya Sakamoto
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan.
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Smetana K, Klamová H, Mikulenková D. Dominant Nucleolus in the Progenitor Cell Using Human Bone Marrow Erythroid and Granulocytic Cell Lineages as a Model. A Morphological and Cytochemical Note. Folia Biol (Praha) 2020; 66:111-115. [PMID: 33069190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Progenitor cells of the human erythroid and granulocytic cell lineages are characterized by the presence of several nucleoli. One of these nucleoli is larger and possesses more fibrillar centres than others. Such nucleolus is apparently dominant in respect of both size and main nucleolar function such as nucleolar-ribosomal RNA transcription. Such nucleolus is also visible in specimens using conventional visualization procedures, in contrast to smaller nucleoli. In the terminal differentiation nucleated stages of the erythroid and granulocytic development, dominant nucleoli apparently disappeared, since these cells mostly contained very small nucleoli of a similar size with one fibrillar centre. Thus, the easily visible dominant nucleoli appear to be useful markers of the progenitor cell state, such as proliferation, and differentiation potential.
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Affiliation(s)
- K Smetana
- Institute of Haematology and Blood Transfusion, Prague, Czech Republic
| | - H Klamová
- Institute of Haematology and Blood Transfusion, Prague, Czech Republic
| | - D Mikulenková
- Institute of Haematology and Blood Transfusion, Prague, Czech Republic
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9
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Martínez-Calvillo S, Florencio-Martínez LE, Nepomuceno-Mejía T. Nucleolar Structure and Function in Trypanosomatid Protozoa. Cells 2019; 8:cells8050421. [PMID: 31071985 PMCID: PMC6562600 DOI: 10.3390/cells8050421] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 04/26/2019] [Accepted: 04/28/2019] [Indexed: 12/12/2022] Open
Abstract
The nucleolus is the conspicuous nuclear body where ribosomal RNA genes are transcribed by RNA polymerase I, pre-ribosomal RNA is processed, and ribosomal subunits are assembled. Other important functions have been attributed to the nucleolus over the years. Here we review the current knowledge about the structure and function of the nucleolus in the trypanosomatid parasites Trypanosoma brucei, Trypanosoma cruzi and Leishmania ssp., which represent one of the earliest branching lineages among the eukaryotes. These protozoan parasites present a single nucleolus that is preserved throughout the closed nuclear division, and that seems to lack fibrillar centers. Trypanosomatids possess a relatively low number of rRNA genes, which encode rRNA molecules that contain large expansion segments, including several that are trypanosomatid-specific. Notably, the large subunit rRNA (28S-type) is fragmented into two large and four small rRNA species. Hence, compared to other organisms, the rRNA primary transcript requires additional processing steps in trypanosomatids. Accordingly, this group of parasites contains the highest number ever reported of snoRNAs that participate in rRNA processing. The number of modified rRNA nucleotides in trypanosomatids is also higher than in other organisms. Regarding the structure and biogenesis of the ribosomes, recent cryo-electron microscopy analyses have revealed several trypanosomatid-specific features that are discussed here. Additional functions of the nucleolus in trypanosomatids are also reviewed.
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Affiliation(s)
- Santiago Martínez-Calvillo
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla CP 54090, Estado de México, Mexico.
| | - Luis E Florencio-Martínez
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla CP 54090, Estado de México, Mexico.
| | - Tomás Nepomuceno-Mejía
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla CP 54090, Estado de México, Mexico.
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10
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Abstract
The nucleolus, where components of the ribosome are constructed, is known to play an important role in various stress responses in animals. However, little is known about the role of the plant nucleolus under environmental stresses such as heat and chilling stress. In this study, we analyzed nucleolus morphology by determining the distribution of newly synthesized rRNAs with an analog of uridine, 5-ethynyl uridine (EU). When EU was incorporated into the root of the Arabidopsis thaliana, EU signals were strongly localized in the nucleolus. The results of the short-term incorporation of EU implied that there is no compartmentation among the processes of transcription, processing, and construction of rRNAs. Nevertheless, under heat and chilling stress, EU was not incorporated into the center of the nucleolus. Morphological analyses using whole rRNA staining and differential interference contrast observations revealed speckled and round structures in the center of the nucleolus under heat and chilling stress, respectively.
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Affiliation(s)
- Kohma Hayashi
- Department of Applied Biological Science Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
| | - Sachihiro Matsunaga
- Department of Applied Biological Science Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan.
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11
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Maina MB, Bailey LJ, Wagih S, Biasetti L, Pollack SJ, Quinn JP, Thorpe JR, Doherty AJ, Serpell LC. The involvement of tau in nucleolar transcription and the stress response. Acta Neuropathol Commun 2018; 6:70. [PMID: 30064522 PMCID: PMC6066928 DOI: 10.1186/s40478-018-0565-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 06/30/2018] [Indexed: 12/16/2022] Open
Abstract
Tau is known for its pathological role in neurodegenerative diseases, including Alzheimer's disease (AD) and other tauopathies. Tau is found in many subcellular compartments such as the cytosol and the nucleus. Although its normal role in microtubule binding is well established, its nuclear role is still unclear. Here, we reveal that tau localises to the nucleolus in undifferentiated and differentiated neuroblastoma cells (SHSY5Y), where it associates with TIP5, a key player in heterochromatin stability and ribosomal DNA (rDNA) transcriptional repression. Immunogold labelling on human brain sample confirms the physiological relevance of this finding by showing tau within the nucleolus colocalises with TIP5. Depletion of tau results in an increase in rDNA transcription with an associated decrease in heterochromatin and DNA methylation, suggesting that under normal conditions tau is involved in silencing of the rDNA. Cellular stress induced by glutamate causes nucleolar stress associated with the redistribution of nucleolar non-phosphorylated tau, in a similar manner to fibrillarin, and nuclear upsurge of phosphorylated tau (Thr231) which doesn't colocalise with fibrillarin or nucleolar tau. This suggests that stress may impact on different nuclear tau species. In addition to involvement in rDNA transcription, nucleolar non-phosphorylated tau also undergoes stress-induced redistribution similar to many nucleolar proteins.
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MESH Headings
- Brain/metabolism
- Brain/ultrastructure
- Cell Differentiation/physiology
- Cell Line, Tumor
- Cell Nucleolus/drug effects
- Cell Nucleolus/metabolism
- Cell Nucleolus/ultrastructure
- Chromosomal Proteins, Non-Histone/metabolism
- Chromosomal Proteins, Non-Histone/ultrastructure
- DNA, Ribosomal/genetics
- DNA, Ribosomal/metabolism
- Excitatory Amino Acid Agonists/pharmacology
- Gene Expression Regulation, Neoplastic/drug effects
- Gene Expression Regulation, Neoplastic/genetics
- Glutamic Acid/pharmacology
- Heterochromatin/physiology
- Histones/metabolism
- Humans
- Immunoprecipitation
- Microscopy, Confocal
- Microscopy, Electron
- Neuroblastoma/pathology
- Neuroblastoma/ultrastructure
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Protein Transport/drug effects
- RNA, Messenger
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Transcription, Genetic/drug effects
- Transfection
- tau Proteins/genetics
- tau Proteins/metabolism
- tau Proteins/ultrastructure
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Affiliation(s)
- Mahmoud B Maina
- School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex, BN1 9QG, UK
- Department of Human Anatomy, College of Medical Science, Gombe State University, Gombe, Nigeria
| | - Laura J Bailey
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, BN1 9RQ, UK
| | - Sherin Wagih
- School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex, BN1 9QG, UK
| | - Luca Biasetti
- School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex, BN1 9QG, UK
| | - Saskia J Pollack
- School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex, BN1 9QG, UK
| | - James P Quinn
- School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex, BN1 9QG, UK
| | - Julian R Thorpe
- School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex, BN1 9QG, UK
| | - Aidan J Doherty
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, BN1 9RQ, UK
| | - Louise C Serpell
- School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex, BN1 9QG, UK.
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12
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Lambertenghi-Deliliers G, Zanon PL, Pozzoli EF, Bellini O. Myocardial Injury Induced by a Single Dose of Adriamycin: An Electron Microscopic Study. Tumori 2018; 62:517-28. [PMID: 1020054 DOI: 10.1177/030089167606200506] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Adriamycin cardiomyopathy has been studied under the electron microscope using myocardial ventricular cells of CRF mice, previously treated with 10 mg/kg body weight of the drug given in a single intravenous injection. Within 10 min myocardial cell nucleoli show a nucleolonema fragmentation, and during the following 3 hours they acquire the nucleolar segregation pattern. Fourteen hours after drug injection, nucleolar morphology again becomes normal, while areas of focal degeneration, characterized by damaged mitochondria and enlarged smooth reticulum cisternae, appear in the sarcoplasm. One to 3 days later the degeneration process involves the myofibrillar component, and after 50 days the great majority of myocardial ventricular cells is damaged. The early appearance and the functional significance of nucleolar segregation support the hypothesis that adriamycin cardiotoxicity might be dependent on its ability to bind to myocardial cell DNA. The consequent failure of UNA and protein synthesis, impairing the continuous renewal of myofibrillar and mitochondrial components of the cell, might explain the progressive myocardial damage.
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13
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Abstract
The silver staining of interphase nucleolar organizer regions (NORs) has been shown to have an important application in diagnostic histopathology for distinguishing some benign from malignant conditions. In this study, normal fetal and adult skeletal muscles and tissue from fetal and adult rhabdomyomas as well as rhabdomyosarcomas were stained with the silver method for NORs. The morphologic distribution of NORs in rhabdomyosarcomas was found to be very different from that in normal skeletal muscles. In addition, cases of rhabdomyoma were easily differentiated from rhabdomyosarcomas. Statistical analysis of data, from all cases, regarding the diameter of NORs and number per nucleus confirmed these observations.
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Affiliation(s)
- V Eusebi
- Istituto Anatomia ed Istologia Patologica, Università degli Studi di Bologna
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14
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Bennett AH, O’Donohue MF, Gundry SR, Chan AT, Widrick J, Draper I, Chakraborty A, Zhou Y, Zon LI, Gleizes PE, Beggs AH, Gupta VA. RNA helicase, DDX27 regulates skeletal muscle growth and regeneration by modulation of translational processes. PLoS Genet 2018. [PMID: 29518074 PMCID: PMC5843160 DOI: 10.1371/journal.pgen.1007226] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [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] [Indexed: 02/06/2023] Open
Abstract
Gene expression in a tissue-specific context depends on the combined efforts of epigenetic, transcriptional and post-transcriptional processes that lead to the production of specific proteins that are important determinants of cellular identity. Ribosomes are a central component of the protein biosynthesis machinery in cells; however, their regulatory roles in the translational control of gene expression in skeletal muscle remain to be defined. In a genetic screen to identify critical regulators of myogenesis, we identified a DEAD-Box RNA helicase, DDX27, that is required for skeletal muscle growth and regeneration. We demonstrate that DDX27 regulates ribosomal RNA (rRNA) maturation, and thereby the ribosome biogenesis and the translation of specific transcripts during myogenesis. These findings provide insight into the translational regulation of gene expression in myogenesis and suggest novel functions for ribosomes in regulating gene expression in skeletal muscles.
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Affiliation(s)
- Alexis H. Bennett
- Division of Genetics, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Marie-Francoise O’Donohue
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, UPS, CNRS, France
| | - Stacey R. Gundry
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Aye T. Chan
- Stem Cell Program and Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jeffrey Widrick
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Isabelle Draper
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, United States of America
| | - Anirban Chakraborty
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, UPS, CNRS, France
- Division of Molecular Genetics and Cancer, NU Centre for Science Education and Research, Nitte University, Mangalore, India
| | - Yi Zhou
- Stem Cell Program and Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Leonard I. Zon
- Stem Cell Program and Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Boston, Massachusetts, United States of America
| | - Pierre-Emmanuel Gleizes
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, UPS, CNRS, France
| | - Alan H. Beggs
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Vandana A. Gupta
- Division of Genetics, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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15
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Douet J, Corujo D, Malinverni R, Renauld J, Sansoni V, Posavec Marjanović M, Cantariño N, Valero V, Mongelard F, Bouvet P, Imhof A, Thiry M, Buschbeck M. MacroH2A histone variants maintain nuclear organization and heterochromatin architecture. J Cell Sci 2017; 130:1570-1582. [PMID: 28283545 DOI: 10.1242/jcs.199216] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 03/07/2017] [Indexed: 12/15/2022] Open
Abstract
Genetic loss-of-function studies on development, cancer and somatic cell reprogramming have suggested that the group of macroH2A histone variants might function through stabilizing the differentiated state by a yet unknown mechanism. Here, we present results demonstrating that macroH2A variants have a major function in maintaining nuclear organization and heterochromatin architecture. Specifically, we find that a substantial amount of macroH2A is associated with heterochromatic repeat sequences. We further identify macroH2A on sites of interstitial heterochromatin decorated by histone H3 trimethylated on K9 (H3K9me3). Loss of macroH2A leads to major defects in nuclear organization, including reduced nuclear circularity, disruption of nucleoli and a global loss of dense heterochromatin. Domains formed by DNA repeat sequences are disorganized, expanded and fragmented, and mildly re-expressed when depleted of macroH2A. At the molecular level, we find that macroH2A is required for the interaction of repeat sequences with the nucleostructural protein lamin B1. Taken together, our results argue that a major function of macroH2A histone variants is to link nucleosome composition to higher-order chromatin architecture.
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Affiliation(s)
- Julien Douet
- Josep Carreras Leukaemia Research Institute (IJC), Campus ICO - Germans Trias i Pujol, Campus Can Ruti, Badalona 08916, Spain
- Program of Predictive and Personalized Medicine of Cancer, Germans Trias and Pujol Research Institute (PMPPC-IGTP), Campus Can Ruti, Badalona 08916, Spain
| | - David Corujo
- Josep Carreras Leukaemia Research Institute (IJC), Campus ICO - Germans Trias i Pujol, Campus Can Ruti, Badalona 08916, Spain
- Program of Predictive and Personalized Medicine of Cancer, Germans Trias and Pujol Research Institute (PMPPC-IGTP), Campus Can Ruti, Badalona 08916, Spain
| | - Roberto Malinverni
- Josep Carreras Leukaemia Research Institute (IJC), Campus ICO - Germans Trias i Pujol, Campus Can Ruti, Badalona 08916, Spain
- Program of Predictive and Personalized Medicine of Cancer, Germans Trias and Pujol Research Institute (PMPPC-IGTP), Campus Can Ruti, Badalona 08916, Spain
| | - Justine Renauld
- Cell and tissue biology unit, GIGA-Neurosciences, University of Liege, C.H.U. Sart Tilman, Liege 4000, Belgium
| | - Viola Sansoni
- BioMedical Center and Center for Integrated Protein Sciences Munich, Ludwig-Maximilians-University of Munich, Großhaderner Straße 9, Planegg-Martinsried 82152, Germany
| | - Melanija Posavec Marjanović
- Josep Carreras Leukaemia Research Institute (IJC), Campus ICO - Germans Trias i Pujol, Campus Can Ruti, Badalona 08916, Spain
| | - Neus Cantariño
- Josep Carreras Leukaemia Research Institute (IJC), Campus ICO - Germans Trias i Pujol, Campus Can Ruti, Badalona 08916, Spain
| | - Vanesa Valero
- Josep Carreras Leukaemia Research Institute (IJC), Campus ICO - Germans Trias i Pujol, Campus Can Ruti, Badalona 08916, Spain
- Program of Predictive and Personalized Medicine of Cancer, Germans Trias and Pujol Research Institute (PMPPC-IGTP), Campus Can Ruti, Badalona 08916, Spain
| | - Fabien Mongelard
- Université de Lyon, Ecole normale Supérieure de Lyon, Centre de Recherche en Cancérologie de Lyon, Cancer Cell Plasticity Department, UMR INSERM 1052 CNRS5286, Centre Léon Bérard, 69008 Lyon, France
| | - Philippe Bouvet
- Université de Lyon, Ecole normale Supérieure de Lyon, Centre de Recherche en Cancérologie de Lyon, Cancer Cell Plasticity Department, UMR INSERM 1052 CNRS5286, Centre Léon Bérard, 69008 Lyon, France
| | - Axel Imhof
- BioMedical Center and Center for Integrated Protein Sciences Munich, Ludwig-Maximilians-University of Munich, Großhaderner Straße 9, Planegg-Martinsried 82152, Germany
| | - Marc Thiry
- Cell and tissue biology unit, GIGA-Neurosciences, University of Liege, C.H.U. Sart Tilman, Liege 4000, Belgium
| | - Marcus Buschbeck
- Josep Carreras Leukaemia Research Institute (IJC), Campus ICO - Germans Trias i Pujol, Campus Can Ruti, Badalona 08916, Spain
- Program of Predictive and Personalized Medicine of Cancer, Germans Trias and Pujol Research Institute (PMPPC-IGTP), Campus Can Ruti, Badalona 08916, Spain
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16
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Mursalimov S, Sidorchuk Y, Deineko E. Behavior of nucleolus in the tobacco male meiocytes involved in cytomixis. Cell Biol Int 2017; 41:340-344. [PMID: 28032378 DOI: 10.1002/cbin.10718] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 12/17/2016] [Indexed: 11/11/2022]
Abstract
Behavior of nucleolus during the nuclear migration between plant cells (cytomixis) is studied for the first time in the tobacco male meiosis. As is shown, the nucleolus is located in a nonrandom manner in the migrating nuclei. In the majority of cases, the nucleolus resides on the nuclear pole strictly opposite to the cytomictic channel. Owing to this localization, the nucleolus extremely rare enters the recipient cell, so that the nucleolar material is in most cases undetectable in the micronuclei formed after cytomixis. When a whole nucleus migrates from a donor cell to recipient, the nucleolus can leave the nucleus and remain in the donor cells either alone or with a small amount of chromatin. The causes underlying a nonrandom location of the nucleolus in cytomictic cells are discussed. It is assumed that the nucleolar material contacts the cytoplasmic cytoskeleton, which prevents migration of the nucleolus into another cell within the nucleus. The potential use of cytomixis as a model for studying the nuclear motion is discussed.
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Affiliation(s)
- Sergey Mursalimov
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Prospekt Lavrentyeva 10, Novosibirsk, 630090, Russia
| | - Yuriy Sidorchuk
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Prospekt Lavrentyeva 10, Novosibirsk, 630090, Russia
| | - Elena Deineko
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Prospekt Lavrentyeva 10, Novosibirsk, 630090, Russia
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17
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Abstract
Here we describe methods for producing nuclei from Arabidopsis suspension cultures or root tips of Arabidopsis, wheat, or pea. These methods could be adapted for other species and cell types. The resulting nuclei can be further purified for use in biochemical or proteomic studies, or can be used for microscopy. We also describe how the nuclei can be used to obtain a preparation of nucleoli.
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Affiliation(s)
- Alison F Pendle
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK
| | - Peter J Shaw
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK.
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18
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Boucheron-Dubuisson E, Manzano AI, Le Disquet I, Matía I, Sáez-Vasquez J, van Loon JJWA, Herranz R, Carnero-Diaz E, Medina FJ. Functional alterations of root meristematic cells of Arabidopsis thaliana induced by a simulated microgravity environment. J Plant Physiol 2016; 207:30-41. [PMID: 27792899 DOI: 10.1016/j.jplph.2016.09.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 09/23/2016] [Accepted: 09/26/2016] [Indexed: 05/20/2023]
Abstract
Environmental gravity modulates plant growth and development, and these processes are influenced by the balance between cell proliferation and differentiation in meristems. Meristematic cells are characterized by the coordination between cell proliferation and cell growth, that is, by the accurate regulation of cell cycle progression and the optimal production of biomass for the viability of daughter cells after division. Thus, cell growth is correlated with the rate of ribosome biogenesis and protein synthesis. We investigated the effects of simulated microgravity on cellular functions of the root meristem in a sequential study. Seedlings were grown in a clinostat, a device producing simulated microgravity, for periods between 3 and 10days. In a complementary study, seedlings were grown in a Random Positioning Machine (RPM) and sampled sequentially after similar periods of growth. Under these conditions, the cell proliferation rate and the regulation of cell cycle progression showed significant alterations, accompanied by a reduction of cell growth. However, the overall size of the root meristem did not change. Analysis of cell cycle phases by flow cytometry showed changes in their proportion and duration, and the expression of the cyclin B1 gene, a marker of entry in mitosis, was decreased, indicating altered cell cycle regulation. With respect to cell growth, the rate of ribosome biogenesis was reduced under simulated microgravity, as shown by morphological and morphometric nucleolar changes and variations in the levels of the nucleolar protein nucleolin. Furthermore, in a nucleolin mutant characterized by disorganized nucleolar structure, the microgravity treatment intensified disorganization. These results show that, regardless of the simulated microgravity device used, a great disruption of meristematic competence was the first response to the environmental alteration detected at early developmental stages. However, longer periods of exposure to simulated microgravity do not produce an intensification of the cellular damages or a detectable developmental alteration in seedlings analyzed at further stages of their growth. This suggests that the secondary response to the gravity alteration is a process of adaptation, whose mechanism is still unknown, which eventually results in viable adult plants.
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Affiliation(s)
- Elodie Boucheron-Dubuisson
- Université Pierre et Marie Curie - Paris 6, Sorbonne Universités, Institut de Systématique, Évolution, Biodiversité, ISYEB - UMR 7205 - CNRS, MNHN, UPMC, EPHE, 57 rue Cuvier, CP50, 75005 Paris, France.
| | - Ana I Manzano
- Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, E-28040 Madrid, Spain.
| | - Isabel Le Disquet
- Université Pierre et Marie Curie - Paris 6, Sorbonne Universités, Institut de Systématique, Évolution, Biodiversité, ISYEB - UMR 7205 - CNRS, MNHN, UPMC, EPHE, 57 rue Cuvier, CP50, 75005 Paris, France.
| | - Isabel Matía
- Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, E-28040 Madrid, Spain.
| | - Julio Sáez-Vasquez
- Laboratoire Génome et Développement des Plantes, CNRS, UMR 5096, Université de Perpignan via Domitia, 66860 Perpignan, France.
| | - Jack J W A van Loon
- DESC (Dutch Experiment Support Center), Dept. Oral and Maxillofacial Surgery/Oral Pathology, VU University Medical Center & Academic Centre for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands; ESA-ESTEC, TEC-MMG, Keplerlaan 1, NL-2200 AG, Noordwijk, The Netherlands.
| | - Raúl Herranz
- Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, E-28040 Madrid, Spain.
| | - Eugénie Carnero-Diaz
- Université Pierre et Marie Curie - Paris 6, Sorbonne Universités, Institut de Systématique, Évolution, Biodiversité, ISYEB - UMR 7205 - CNRS, MNHN, UPMC, EPHE, 57 rue Cuvier, CP50, 75005 Paris, France.
| | - F Javier Medina
- Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, E-28040 Madrid, Spain.
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19
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Valdebran M, Elbendary A, Chaitanya Arudra SK, Torres KM, Elattar I, Elston DM. Nuclear and cytoplasmic features in the diagnosis of banal nevi, Spitz nevi, and melanoma. J Am Acad Dermatol 2016; 75:1032-1037.e8. [PMID: 27542585 DOI: 10.1016/j.jaad.2016.06.051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 06/19/2016] [Accepted: 06/22/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Many authors have described cytologic features in a variety of melanocytic lesions but, to our knowledge, a statistical analysis of sensitivity, specificity, and overall accuracy of these features alone or in combination has not been performed. OBJECTIVE We sought to determine the diagnostic value of nuclear and cytoplasmic characteristics in the diagnosis of melanocytic lesions via multivariate statistical analysis. METHODS This is a retrospective observational study conducted on 300 melanocytic lesions. We evaluated a series of distinctive features; subsequently a multivariate model was used to determine sensitivity and specificity. RESULTS Major features that favor a diagnosis of melanoma include: pleomorphism with enlarged nuclei, mitotic figures, notching/corrugation of the nuclear envelope, and peppered moth nucleus. Features with intermediate value include: solid hyperchromasia, vesicular nucleus with single round nucleolus, and nuclear/cytoplasmic ratio greater than 4:1. LIMITATIONS Limitations of this study include its retrospective nature, and the reliance on the original diagnostic classification of each neoplasm. CONCLUSION Our data suggest that some nuclear alterations have greater value in the diagnosis of benign and malignant melanocytic lesions.
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Affiliation(s)
| | - Amira Elbendary
- Ackerman Academy of Dermatopathology, New York, New York; Department of Dermatology, Kasr Al Ainy Faculty of Medicine, Cairo University, Cairo, Egypt
| | | | | | - Inas Elattar
- Department of Biostatistics and Cancer Epidemiology, National Cancer Institute, Kasr Al Ainy Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Dirk M Elston
- Department of Dermatology and Dermatologic Surgery, Medical University of South Carolina, Charleston, South Carolina.
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20
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Franek M, Kovaříková A, Bártová E, Kozubek S. Nucleolar Reorganization Upon Site-Specific Double-Strand Break Induction. J Histochem Cytochem 2016; 64:669-686. [PMID: 27680669 PMCID: PMC5084524 DOI: 10.1369/0022155416668505] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 08/09/2016] [Indexed: 12/20/2022] Open
Abstract
DNA damage response (DDR) in ribosomal genes and mechanisms of DNA repair in embryonic stem cells (ESCs) are less explored nuclear events. DDR in ESCs should be unique due to their high proliferation rate, expression of pluripotency factors, and specific chromatin signature. Given short population doubling time and fast progress through G1 phase, ESCs require a sustained production of rRNA, which leads to the formation of large and prominent nucleoli. Although transcription of rRNA in the nucleolus is relatively well understood, little is known about DDR in this nuclear compartment. Here, we directed formation of double-strand breaks in rRNA genes with I- PpoI endonuclease, and we studied nucleolar morphology, DDR, and chromatin modifications. We observed a pronounced formation of I- PpoI-induced nucleolar caps, positive on BRCA1, NBS1, MDC1, γH2AX, and UBF1 proteins. We showed interaction of nucleolar protein TCOF1 with HDAC1 and TCOF1 with CARM1 after DNA injury. Moreover, H3R17me2a modification mediated by CARM1 was found in I- PpoI-induced nucleolar caps. Finally, we report that heterochromatin protein 1 is not involved in DNA repair of nucleolar caps.
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Affiliation(s)
- Michal Franek
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic (MF, AK, EB, SK)
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21
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Derenzini M, Pasquinelli G, O'Donohue MF, Ploton D, Thiry M. Structural and Functional Organization of Ribosomal Genes within the Mammalian Cell Nucleolus. J Histochem Cytochem 2016; 54:131-45. [PMID: 16204224 DOI: 10.1369/jhc.5r6780.2005] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [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: 11/22/2022] Open
Abstract
Data on the in situ structural–functional organization of ribosomal genes in the mammalian cell nucleolus are reviewed here. Major findings on chromatin structure in situ come from investigations carried out using the Feulgen-like osmium ammine reaction as a highly specific electron-opaque DNA tracer. Intranucleolar chromatin shows three different levels of organization: compact clumps, fibers ranging from 11 to 30 nm, and loose agglomerates of extended DNA filaments. Both clumps and fibers of chromatin exhibit a nucleosomal organization that is lacking in the loose agglomerates of extended DNA filaments. In fact, these filaments constantly show a thickness of 2–3 nm, the same as a DNA doublehelix molecule. The loose agglomerates of DNA filaments are located in the fibrillar centers, the interphase counterpart of metaphase NORs, therefore being constituted by ribosomal DNA. The extended, non-nucleosomal configuration of this rDNA has been shown to be independent of transcriptional activity and characterizes ribosome genes that are either transcribed or transcriptionally silent. Data reviewed are consistent with a model of control for ribosome gene activity that is not mediated by changes in chromatin structure. The presence of rDNA in mammalian cells always structurally ready for transcription might facilitate a more rapid adjustment of the ribosome production in response to the metabolic needs of the cell.
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Affiliation(s)
- Massimo Derenzini
- Dipartimento di Patologia Sperimentale, Via S. Giacomo 14, 40126 Bologna, Italy.
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22
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Abstract
Nucleoli form around RNA polymerase I transcribed ribosomal RNA (rRNA) genes. The direct electron microscopy observation of rRNA genes after nucleolar chromatin spreading (Miller's spreads) constitutes to date the only system to quantitatively assess transcription at a single molecule level. However, the spreading procedure is likely generating artifact and despite being informative, these spread rRNA genes are far from their in vivo situation. The integration of the structural characterization of spread rRNA genes in the three-dimensional (3D) organization of the nucleolus would represent an important scientific achievement. Here, we describe a correlative light and electron microscopy (CLEM) protocol allowing detection of tagged-Pol I by fluorescent microscopy and high-resolution imaging of the nucleolar ultrastructural context. This protocol can be implemented in laboratories equipped with conventional fluorescence and electron microscopes and does not require sophisticated "pipeline" for imaging.
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Affiliation(s)
- Christophe Normand
- Laboratoire de Biologie Moléculaire du CNRS, University of Toulouse, 118 route de Narbonne, 31000, Toulouse, France
| | - Maxime Berthaud
- CRCNA-UMR 892 INSERM, Nantes, France
- CNRS, Nantes, France
- University of Nantes, Nantes, France
| | - Olivier Gadal
- Laboratoire de Biologie Moléculaire du CNRS, University of Toulouse, 118 route de Narbonne, 31000, Toulouse, France.
| | - Isabelle Léger-Silvestre
- Laboratoire de Biologie Moléculaire du CNRS, University of Toulouse, 118 route de Narbonne, 31000, Toulouse, France.
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23
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Żelazowska M, Jankowska W, Plewniak E, Rajek U. Ovarian nests in cultured Russian sturgeon Acipenser gueldenstaedtii and North American paddlefish Polyodon spathula comprised of previtellogenic oocytes. J Fish Biol 2015; 86:1669-1679. [PMID: 25809946 DOI: 10.1111/jfb.12663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 02/06/2015] [Indexed: 06/04/2023]
Abstract
Ovarian nests in the ovaries of sexually maturing Russian sturgeon Acipenser gueldenstaedtii and North American paddlefish Polyodon spathula were investigated. They comprised early previtellogenic, diplotene stage oocytes and somatic cells. In the nucleoplasm, these oocytes contained chromatin in the form of grains, threads and lampbrush chromosomes, primary nucleoli and multiple nucleoli. Two stages of oocytes in nests were distinguished by differences in the distribution of mitochondria with distorted cristae and lipid droplets in the ooplasm. These stages were as follows: pre-early stage 1 (PE 1) and early stage 1 (EP 1) previtellogenic oocytes. In PE 1 oocytes few mitochondria with distorted cristae and lipid droplets were distributed randomly. The ooplasm of PE 1 oocytes was not differentiated into homogeneous and granular compartments. In EP 1 oocytes, mitochondria with distorted cristae were more numerous and grouped in the vicinity of the nucleus, lipid droplets accumulated near these mitochondria. In the nucleoplasm of EP 1 oocytes several low electron-dense spherical bodies, possibly Cajal bodies, were present.
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Affiliation(s)
- M Żelazowska
- Department of Developmental Biology and Morphology of Invertebrates, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland
| | - W Jankowska
- Department of Developmental Biology and Morphology of Invertebrates, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland
| | - E Plewniak
- Department of Developmental Biology and Morphology of Invertebrates, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland
| | - U Rajek
- Department of Developmental Biology and Morphology of Invertebrates, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland
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Kenney SP, Meng XJ. Identification and fine mapping of nuclear and nucleolar localization signals within the human ribosomal protein S17. PLoS One 2015; 10:e0124396. [PMID: 25853866 PMCID: PMC4390217 DOI: 10.1371/journal.pone.0124396] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [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: 12/21/2014] [Accepted: 03/13/2015] [Indexed: 01/29/2023] Open
Abstract
Human ribosomal protein S17 (RPS17) is mutated in Diamond-Blackfan Anemia (DBA), a bone marrow disorder that fails to produce sufficient red blood cells leading to anemia. Recently, an RPS17 protein sequence was also found to be naturally inserted in the genome of hepatitis E virus (HEV) from patients chronically-infected by HEV. The role of RPS17 in HEV replication and pathogenesis remains unknown due to the lack of knowledge about how RPS17 functions at a molecular level. Understanding the biological function of RPS17 is critical for elucidating its role in virus infection and DBA disease processes. In this study we probed the subcellular distribution of normal and mutant RPS17 proteins in a human liver cell line (Huh7). RPS17 was primarily detected within the nucleus, and more specifically within the nucleoli. Using a transient expression system in which RPS17 or truncations were expressed as fusions with enhanced yellow fluorescent protein (eYFP), we were able to identify and map, for the first time, two separate nuclear localization signals (NLSs), one to the first 13 amino acids of the amino-terminus of RPS17 and the other within amino acids 30-60. Additionally, we mapped amino acid sequences required for nucleolar accumulation of RPS17 to amino acids 60-70. Amino acids 60-70 possess a di-RG motif that may be necessary for nucleolar retention of RPS17. The results from this study enhance our knowledge of RSP17 and will facilitate future mechanistic studies about the roles of RSP17 in hepatitis E and DBA disease processes.
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Affiliation(s)
- Scott P. Kenney
- Center for Molecular Medicine and Infectious Diseases, Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, Virginia, United States of America
| | - Xiang-Jin Meng
- Center for Molecular Medicine and Infectious Diseases, Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, Virginia, United States of America
- * E-mail:
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25
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Rocha LC, Bustamante FDO, Silveira RAD, Torres GA, Mittelmann A, Techio VH. Functional repetitive sequences and fragile sites in chromosomes of Lolium perenne L. Protoplasma 2015; 252:451-60. [PMID: 25141824 DOI: 10.1007/s00709-014-0690-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 08/13/2014] [Indexed: 05/26/2023]
Abstract
Lolium perenne is considered a high-quality forage widely used in temperate regions to meet the shortage of forage during the winter. In this species, some peculiarities related to cytogenetic aspects have already been described, as the variability in number and position of 45S ribosomal DNA (rDNA) sites and the expression of fragile sites, which require further studies to support the understanding of their causes and consequences. In this way, this study aimed to evaluate the relationship between the expression of fragile sites and functional repetitive sequences (rDNA and telomeric) in chromosomes of diploid and polyploid cultivars of L. perenne. The techniques of FISH, Ag-NOR and fluorescence banding were used to assess the distribution of sites of 45S rDNA, 5S, telomeric sequences, and the transcriptional activity of the 45S ribosomal genes and the distribution of AT- and/or GC-rich sequences in L. perenne, respectively. There was variability in the number and location of 45S rDNA sites, which was not observed for 5S rDNA sites. One of the genotypes showed two 45S rDNA sites on the same chromosome, located in different chromosome arms. Breaks and gaps were found in 45S rDNA sites in most metaphases evaluated for both cultivars. Telomeric sequences were not detected at the end of the chromosomal fragments corresponding to the location of breaks at 45S sites. Apparently, the transcriptional activity was modified in fragile sites. Variation in the number and size of nucleoli, nucleolar fusions and dissociations were observed. All CMA(+) bands were colocalized with the 45S sites.
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Affiliation(s)
- Laiane Corsini Rocha
- Department of Biology, Federal University of Lavras, P.O. Box 3037, 37200-000, Lavras, Minas Gerais State, Brazil
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26
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Farley KI, Surovtseva Y, Merkel J, Baserga SJ. Determinants of mammalian nucleolar architecture. Chromosoma 2015; 124:323-31. [PMID: 25670395 DOI: 10.1007/s00412-015-0507-z] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [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: 12/01/2014] [Revised: 01/22/2015] [Accepted: 01/26/2015] [Indexed: 11/30/2022]
Abstract
The nucleolus is responsible for the production of ribosomes, essential machines which synthesize all proteins needed by the cell. The structure of human nucleoli is highly dynamic and is directly related to its functions in ribosome biogenesis. Despite the importance of this organelle, the intricate relationship between nucleolar structure and function remains largely unexplored. How do cells control nucleolar formation and function? What are the minimal requirements for making a functional nucleolus? Here we review what is currently known regarding mammalian nucleolar formation at nucleolar organizer regions (NORs), which can be studied by observing the dissolution and reformation of the nucleolus during each cell division. Additionally, the nucleolus can be examined by analyzing how alterations in nucleolar function manifest in differences in nucleolar architecture. Furthermore, changes in nucleolar structure and function are correlated with cancer, highlighting the importance of studying the determinants of nucleolar formation.
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Affiliation(s)
- Katherine I Farley
- Department of Molecular Biophysics & Biochemistry, Yale University School of Medicine, New Haven, CT, 06520, USA
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27
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Souquere S, Weil D, Pierron G. Comparative ultrastructure of CRM1-Nucleolar bodies (CNoBs), Intranucleolar bodies (INBs) and hybrid PML/p62 bodies uncovers new facets of nuclear body dynamic and diversity. Nucleus 2015; 6:326-38. [PMID: 26275159 PMCID: PMC4615761 DOI: 10.1080/19491034.2015.1082695] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 08/07/2015] [Accepted: 08/10/2015] [Indexed: 12/24/2022] Open
Abstract
In order to gain insights on the nuclear organization in mammalian cells, we characterized ultrastructurally nuclear bodies (NBs) previously described as fluorescent foci. Using high resolution immunoelectron microscopy (I-EM), we provide evidence that CNoBs (CRM1-Nucleolar bodies) and INBs (Intranucleolar bodies) are distinct genuine nucleolar structures in untreated HeLa cells. INBs are fibrillar and concentrate the post-translational modifiers SUMO1 and SUMO-2/3 as strongly as PML bodies. In contrast, the smallest CRM1-labeled CNoBs are vitreous, preferentially located at the periphery of the nucleolus and, intricately linked to the chromatin network. Upon blockage of the CRM1-dependent nuclear export by leptomycin B (LMB), CNoBs disappear while p62/SQSTM1-containing fibrillar nuclear bodies are induced. These p62 bodies are enriched in ubiquitinated proteins. They progressively associate with PML bodies to form hybrid bodies of which PML decorates the periphery while p62/SQSTM1 is centrally-located. Our study is expanding the repertoire of nuclear bodies; revealing a previously unrecognized composite nucleolar landscape and a new mode of interactions between ubiquitous (PML) and stress-induced (p62) nuclear bodies, resulting in the formation of hybrid bodies.
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Affiliation(s)
- Sylvie Souquere
- Functional Organization of the Cell; CNRS UMR-9196; Institut Gustave Roussy; Villejuif, France
| | - Dominique Weil
- UPMC Univ Paris 06; Institut de Biologie Paris-Seine (IBPS); CNRS UMR-7622; Paris, France
| | - Gérard Pierron
- Functional Organization of the Cell; CNRS UMR-9196; Institut Gustave Roussy; Villejuif, France
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28
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Abstract
Nuclear architecture is highly concerted including the organization of chromosome territories and distinct nuclear bodies, such as nucleoli, Cajal bodies, nuclear speckles of splicing factors, and promyelocytic leukemia nuclear bodies, among others. The organization of such nuclear compartments is very dynamic and may represent a sensitive indicator of the functional status of the cell. Here, we describe methodologies that allow isolating discrete cell populations from the brain and the fine observation of nuclear signs that could be insightful predictors of an early neuronal injury in a wide range of neurodegenerative disorders. The tools here described may be of use for the early detection of pre-degenerative processes in neurodegenerative diseases and for validating novel rescue strategies.
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Affiliation(s)
- Fernando C Baltanás
- Institute for Molecular and Cell Biology of the Cancer, CSIC - Universidad de Salamanca, Salamanca, Spain
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29
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Legartová S, Sbardella G, Kozubek S, Bártová E. Ellagic Acid-Changed Epigenome of Ribosomal Genes and Condensed RPA194-Positive Regions of Nucleoli in Tumour Cells. Folia Biol (Praha) 2015; 61:49-59. [PMID: 26333121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We studied the effect of ellagic acid (EA) on the morphology of nucleoli and on the pattern of major proteins of the nucleolus. After EA treatment of HeLa cells, we observed condensation of nucleoli as documented by the pattern of argyrophilic nucleolar organizer regions (AgNORs). EA also induced condensation of RPA194-positive nucleolar regions, but no morphological changes were observed in nucleolar compartments positive for UBF1/2 proteins or fibrillarin. Studied morphological changes induced by EA were compared with the morphology of control, non-treated cells and with pronounced condensation of all nucleolar domains caused by actinomycin D (ACT-D) treatment. Similarly as ACT-D, but in a lesser extent, EA induced an increased number of 53BP1-positive DNA lesions. However, the main marker of DNA lesions, γH2AX, was not accumulated in body-like nuclear structures. An increased level of γH2AX was found by immunofluorescence and Western blots only after EA treatment. Intriguingly, the levels of fibrillarin, UBF1/2 and γH2AX were increased at the promoters of ribosomal genes, while 53BP1 and CARM1 levels were decreased by EA treatment at these genomic regions. In the entire genome, EA reduced H3R17 dimethylation. Taken together, ellagic acid is capable of significantly changing the nucleolar morphology and protein levels inside the nucleolus.
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Affiliation(s)
- S Legartová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v. v. i., Brno, Czech Republic
| | - G Sbardella
- Epigenetic MedChem Lab, Università di Salerno Dipartimento di Farmacia, Fisciano, Salerno, Italy
| | - S Kozubek
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v. v. i., Brno, Czech Republic
| | - E Bártová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v. v. i., Brno, Czech Republic
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Abstract
Nucleoli are nuclear domains present in almost all eukaryotic cells. They not only specialize in the production of ribosomal subunits but also play roles in many fundamental cellular activities. Concerning ribosome biosynthesis, particular stages of this process, i.e., ribosomal DNA transcription, primary RNA transcript processing, and ribosome assembly proceed in precisely defined nucleolar subdomains. Although eukaryotic nucleoli are conservative in respect of their main function, clear morphological differences between these structures can be noticed between individual kingdoms. In most cases, a plant nucleolus shows well-ordered structure in which four main ultrastructural components can be distinguished: fibrillar centers, dense fibrillar component, granular component, and nucleolar vacuoles. Nucleolar chromatin is an additional crucial structural component of this organelle. Nucleolonema, although it is not always an unequivocally distinguished nucleolar domain, has often been described as a well-grounded morphological element, especially of plant nucleoli. The ratios and morphology of particular subcompartments of a nucleolus can change depending on its metabolic activity which in turn is correlated with the physiological state of a cell, cell type, cell cycle phase, as well as with environmental influence. Precise attribution of functions to particular nucleolar subregions in the process of ribosome biosynthesis is now possible using various approaches. The presented description of plant nucleolar morphology summarizes previous knowledge regarding the function of nucleoli as well as of their particular subdomains not only in the course of ribosome biosynthesis.
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Affiliation(s)
- Dariusz Stępiński
- Department of Cytophysiology, Faculty of Biology and Environmental Protection, University of Łódź, Pomorska 141/143, 90-236, Łódź, Poland,
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Zhang YJ, Jansen-West K, Xu YF, Gendron TF, Bieniek KF, Lin WL, Sasaguri H, Caulfield T, Hubbard J, Daughrity L, Chew J, Belzil VV, Prudencio M, Stankowski JN, Castanedes-Casey M, Whitelaw E, Ash PEA, DeTure M, Rademakers R, Boylan KB, Dickson DW, Petrucelli L. Aggregation-prone c9FTD/ALS poly(GA) RAN-translated proteins cause neurotoxicity by inducing ER stress. Acta Neuropathol 2014; 128:505-24. [PMID: 25173361 PMCID: PMC4159567 DOI: 10.1007/s00401-014-1336-5] [Citation(s) in RCA: 240] [Impact Index Per Article: 24.0] [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: 03/23/2014] [Revised: 08/20/2014] [Accepted: 08/20/2014] [Indexed: 12/13/2022]
Abstract
The occurrence of repeat-associated non-ATG (RAN) translation, an atypical form of translation of expanded repeats that results in the synthesis of homopolymeric expansion proteins, is becoming more widely appreciated among microsatellite expansion disorders. Such disorders include amyotrophic lateral sclerosis and frontotemporal dementia caused by a hexanucleotide repeat expansion in the C9ORF72 gene (c9FTD/ALS). We and others have recently shown that this bidirectionally transcribed repeat is RAN translated, and the "c9RAN proteins" thusly produced form neuronal inclusions throughout the central nervous system of c9FTD/ALS patients. Nonetheless, the potential contribution of c9RAN proteins to disease pathogenesis remains poorly understood. In the present study, we demonstrate that poly(GA) c9RAN proteins are neurotoxic and may be implicated in the neurodegenerative processes of c9FTD/ALS. Specifically, we show that expression of poly(GA) proteins in cultured cells and primary neurons leads to the formation of soluble and insoluble high molecular weight species, as well as inclusions composed of filaments similar to those observed in c9FTD/ALS brain tissues. The expression of poly(GA) proteins is accompanied by caspase-3 activation, impaired neurite outgrowth, inhibition of proteasome activity, and evidence of endoplasmic reticulum (ER) stress. Of importance, ER stress inhibitors, salubrinal and TUDCA, provide protection against poly(GA)-induced toxicity. Taken together, our data provide compelling evidence towards establishing RAN translation as a pathogenic mechanism of c9FTD/ALS, and suggest that targeting the ER using small molecules may be a promising therapeutic approach for these devastating diseases.
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Affiliation(s)
- Yong-Jie Zhang
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Karen Jansen-West
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Ya-Fei Xu
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Tania F. Gendron
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Kevin F. Bieniek
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
- Mayo Graduate School, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
| | - Wen-Lang Lin
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Hiroki Sasaguri
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Thomas Caulfield
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Jaime Hubbard
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Lillian Daughrity
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Jeannie Chew
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
- Mayo Graduate School, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
| | | | - Mercedes Prudencio
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | | | | | - Ena Whitelaw
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Peter E. A. Ash
- Department of Pharmacology, Boston University School of Medicine, Boston, MA 02118 USA
| | - Michael DeTure
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Rosa Rademakers
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Kevin B. Boylan
- Department of Neurology, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Dennis W. Dickson
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
| | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224 USA
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33
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Booth DG, Takagi M, Sanchez-Pulido L, Petfalski E, Vargiu G, Samejima K, Imamoto N, Ponting CP, Tollervey D, Earnshaw WC, Vagnarelli P. Ki-67 is a PP1-interacting protein that organises the mitotic chromosome periphery. eLife 2014; 3:e01641. [PMID: 24867636 PMCID: PMC4032110 DOI: 10.7554/elife.01641] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Accepted: 04/27/2014] [Indexed: 12/23/2022] Open
Abstract
When the nucleolus disassembles during open mitosis, many nucleolar proteins and RNAs associate with chromosomes, establishing a perichromosomal compartment coating the chromosome periphery. At present nothing is known about the function of this poorly characterised compartment. In this study, we report that the nucleolar protein Ki-67 is required for the assembly of the perichromosomal compartment in human cells. Ki-67 is a cell-cycle regulated protein phosphatase 1-binding protein that is involved in phospho-regulation of the nucleolar protein B23/nucleophosmin. Following siRNA depletion of Ki-67, NIFK, B23, nucleolin, and four novel chromosome periphery proteins all fail to associate with the periphery of human chromosomes. Correlative light and electron microscopy (CLEM) images suggest a near-complete loss of the entire perichromosomal compartment. Mitotic chromosome condensation and intrinsic structure appear normal in the absence of the perichromosomal compartment but significant differences in nucleolar reassembly and nuclear organisation are observed in post-mitotic cells.DOI: http://dx.doi.org/10.7554/eLife.01641.001.
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Affiliation(s)
- Daniel G Booth
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Masatoshi Takagi
- Cellular Dynamics Laboratory, Riken Advanced Science Institute, Wako Saitama, Japan
| | - Luis Sanchez-Pulido
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Elizabeth Petfalski
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Giulia Vargiu
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Kumiko Samejima
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Naoko Imamoto
- Cellular Dynamics Laboratory, Riken Advanced Science Institute, Wako Saitama, Japan
| | - Chris P Ponting
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - David Tollervey
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
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Ponti D, Bellenchi GC, Puca R, Bastianelli D, Maroder M, Ragona G, Roussel P, Thiry M, Mercola D, Calogero A. The transcription factor EGR1 localizes to the nucleolus and is linked to suppression of ribosomal precursor synthesis. PLoS One 2014; 9:e96037. [PMID: 24787739 PMCID: PMC4006901 DOI: 10.1371/journal.pone.0096037] [Citation(s) in RCA: 15] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 04/03/2014] [Indexed: 01/13/2023] Open
Abstract
EGR1 is an immediate early gene with a wide range of activities as transcription factor, spanning from regulation of cell growth to differentiation. Numerous studies show that EGR1 either promotes the proliferation of stimulated cells or suppresses the tumorigenic growth of transformed cells. Upon interaction with ARF, EGR1 is sumoylated and acquires the ability to bind to specific targets such as PTEN and in turn to regulate cell growth. ARF is mainly localized to the periphery of nucleolus where is able to negatively regulate ribosome biogenesis. Since EGR1 colocalizes with ARF under IGF-1 stimulation we asked the question of whether EGR1 also relocate to the nucleolus to interact with ARF. Here we show that EGR1 colocalizes with nucleolar markers such as fibrillarin and B23 in the presence of ARF. Western analysis of nucleolar extracts from HeLa cells was used to confirm the presence of EGR1 in the nucleolus mainly as the 100 kDa sumoylated form. We also show that the level of the ribosomal RNA precursor 47S is inversely correlated to the level of EGR1 transcripts. The EGR1 iseffective to regulate the synthesis of the 47S rRNA precursor. Then we demonstrated that EGR1 binds to the Upstream Binding Factor (UBF) leading us to hypothesize that the regulating activity of EGR1 is mediated by its interaction within the transcriptional complex of RNA polymerase I. These results confirm the presence of EGR1 in the nucleolus and point to a role for EGR1 in the control of nucleolar metabolism.
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Affiliation(s)
- Donatella Ponti
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | | | - Rosa Puca
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Daniela Bastianelli
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Marella Maroder
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Giuseppe Ragona
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Pascal Roussel
- RNA Biology, FRE 3402 CNRS-Universitè Pierre et Marie Curie, Paris, France
| | - Marc Thiry
- Unit of Cell Biology, GIGA-Neuroscience, University of Liege, CHU SartTilman, Liege, Belgium
| | - Dan Mercola
- Department of Pathology and Laboratory Medicine, University of California, Irvine, California, United States of America
| | - Antonella Calogero
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
- * E-mail:
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35
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Abstract
In eukaryotic cells, ribosome biogenesis occurs in the nucleolus, a membraneless nuclear compartment. Noticeably, the nucleolus is also involved in several nuclear functions, such as cell cycle regulation, non-ribosomal ribonucleoprotein complex assembly, aggresome formation and some virus assembly. The most intriguing question about the nucleolus is how such dynamics processes can occur in such a compact compartment. We hypothesized that its structure may be rather flexible. To investigate this, we used atomic force microscopy (AFM) on isolated nucleoli. Surface topography imaging revealed the beaded structure of the nucleolar surface. With the AFM's ability to measure forces, we were able to determine the stiffness of isolated nucleoli. We could establish that the nucleolar stiffness varies upon drastic morphological changes induced by transcription and proteasome inhibition. Furthermore, upon ribosomal proteins and LaminB1 knockdowns, the nucleolar stiffness was increased. This led us to propose a model where the nucleolus has steady-state stiffness dependent on ribosome biogenesis activity and requires LaminB1 for its flexibility.
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Affiliation(s)
- Emilie Louvet
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan,
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36
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Petrov IP, Neguliaev IA, Tsupkina NV. [Colocalization of nucleoli in cell nuclei of HeLa line]. Tsitologiia 2014; 56:197-203. [PMID: 25509415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The pattern of localization of nucleoli relative to each other and to cell nucleus was studied in M-HeLa cell line. For this puspose, the following morphometric parameters were introduced. For the two-nucleolar cells: 1) the ratio of the nucleus long axis to the length of a segment between the centers of the nucleoli, and 2) the angle between the segment connecting the centers of the nucleoli and a longitudinal axis of cell nucleus. For the three-nucleolar cells: the ratio perimeter of the nucleus to perimeter of a triangle with vertexes in the centre of nucleoli. We have shown that the values of these parameters are individual for each cell but their values remain constant for the cell in spite of the changes in cell shape. These results allow us to conclude that, on the one hand, the nucleoli colocalization is individual for each cell, and, on the other hand, location of nucleoli in relation to nucleus is not changed during interphase. Thereby, the distance between nucleoli increases proportionally with nucleus growth.
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37
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Murasheva MI, Chentsov IS. [Immunochemical study of nuclear matrix proteins localization in the structure of perinucleolar chromatin]. Tsitologiia 2014; 56:809-815. [PMID: 25707207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Immunofluorescence labeling of proteins with molecular mass of 27, 38, 40, 50 and 65 kDa obtained from serum of patients with autoimmune disease demonstrated different patterns (small clusters or granules) in interphase nuclei of pig kidney cells. It was remarkable that there was no staining inside the nucleoli, but the proteins immunoreactivity was detected around them in the regions of perinucleolar chromatin. Moreover, expression of nucleolar proteins, such as fibrillarin and B23, was found only in nucleoli. After extraction of DNA, PNA and histones, the proteins with molecular mass 27 and 38 kDa were found in the periphery of residual nucleoli, and proteins with molecular mass 40, 50 and 65 kDa had similar localization and were also present in karyoplasm of cells as small clusters. According to our data, nucleolar protein, fibrillarin, was distributed regularly throughout the whole volume of residual nucleoli. At the same time, B23 protein was revealed only at their periphery, where perinucleolar chromatin had localized before treatment. Thus, it has been revealed that the proteins of nuclear matrix with molecular mass 27, 38, 40, 50 and 65 kDa, as well as nucleolar protein B23 are the parts of perinucleolar chromatin, which could be considered as special chromosomal domain associated with the functioning of the nucleolus.
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38
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Tychinsky V, Kretushev AV, Klemyashov IV, Zverzhkhovskiy VD, Vyshenskaya TV, Shtil AA. Quantitative phase imaging of living cells: application of the phase volume and area functions to the analysis of "nucleolar stress". J Biomed Opt 2013; 18:111413. [PMID: 23974227 DOI: 10.1117/1.jbo.18.11.111413] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We applied coherent phase microscopy to develop a method of quantitative evaluation of functional state of eukaryotic cells using the coordinates of characteristic points (CP) in the functions of the phase volume W and area S. In a fragment of a single cell image (HCT116 human colon carcinoma cell line) with detectable nucleolus, the values of the phase thickness, area, and volume were calculated. These values dramatically changed within the initial minutes of cell exposure to the transcriptional inhibitor actinomycin D. The positions of CP in the graphs of S and W functions allowed for monitoring the time-dependent decrease of nucleolar contrast, a major optical hallmark of "nucleolar stress." Given that the area and volume functions reflect optical heterogeneity of the cell and are independent of its optical model, these functions can be applicable as general mathematical tools for the analysis of cell morphology and physiology.
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Affiliation(s)
- Vladimir Tychinsky
- Moscow Institute of Radioengineering, Electronics and Automation, 78 Vernadsky Avenue, Moscow 119454, Russian Federation.
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39
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Stępiński D. Nucleolar chromatin organization at different activities of soybean root meristematic cell nucleoli. Protoplasma 2013; 250:723-30. [PMID: 23011403 PMCID: PMC3659268 DOI: 10.1007/s00709-012-0456-9] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 09/11/2012] [Indexed: 05/10/2023]
Abstract
Nucleolar chromatin, including nucleolus-associated chromatin as well as active and inactive condensed ribosomal DNA (rDNA) chromatin, derives mostly from secondary constrictions known as nucleolus organizer regions containing rDNA genes on nucleolus-forming chromosomes. This chromatin may occupy different nucleolar positions being in various condensation states which may imply different rDNA transcriptional competence. Sections of nucleoli originating from root meristematic cells of soybean seedlings grown at 25 °C (the control), then subjected to chilling stress (10 °C), and next transferred again to 25 °C (the recovery) were used to measure profile areas occupied by nucleolar condensed chromatin disclosed with sodium hydroxide methylation-acetylation plus uranyl acetate technique. The biggest total area of condensed chromatin was found in the nucleoli of chilled plants, while the smallest was found in those of recovered plants in relation to the amounts of chromatin in the control nucleoli. The condensed nucleolar chromatin, in the form of different-sized and different-shaped clumps, was mainly located in fibrillar centers. One can suppose that changes of condensed rDNA chromatin amounts might be a mechanism controlling the number of transcriptionally active rDNA genes as the nucleoli of plants grown under these experimental conditions show different transcriptional activity and morphology.
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Affiliation(s)
- Dariusz Stępiński
- Department of Cytophysiology, Faculty of Biology and Environmental Protection, University of Łódź, Pomorska 141/143, 90-236, Łódź, Poland.
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40
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Pérez-Pedrosa A, Ortiz-Rey JA, Lorenzo-Mahía Y, Iglesias-Rodríguez B, Peteiro-Cancelo A, González-Carreró J. Interobserver reproducibility of a grading system for chromophobe renal cell carcinoma. Actas Urol Esp 2013; 37:338-41. [PMID: 23058995 DOI: 10.1016/j.acuro.2012.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 03/19/2012] [Accepted: 04/05/2012] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To evaluate interobserver reproducibility of a grading system proposed by Paner et al. for chromophobe renal cell carcinoma. MATERIAL AND METHODS After selecting 23 cases of chromophobe renal cell carcinoma from the Xeral-Cíes Hospital, Meixoeiro Hospital and POVISA Hospital from the last 15 years, an informative meeting on the Paner et al. grading system criteria was held. After, the participating pathologists applied the system to each case, evaluating one slide selected. Kappa index for interobserver reproducibility was calculated, and it was classified according to the Landis and Koch scale. RESULTS The grading distribution was similar for most of the 6 participating observers, with grade 1 predominance. The remaining 2 observers considered a relatively higher proportion of grade 2. Kappa index values ranged from 0.136 to 0.674, with a discrete-moderate reproducibility index predominance (0.21-0.60). Highest Kappa value (0.674) was obtained between the most novel and the most expert interobservers. The lowest Kappa value was obtained among the most veteran pathologists (0.136). CONCLUSIONS Interobserver reproducibility for chromophobe renal cell carcinoma is discrete-moderate in our institutions when the novel grade proposed by Paner et al. is used. Labeling of grades 1 and 2 is not homogeneous among 6 participating observers. While awaiting a grading consensus on a new classification by the scientific societies, we consider that the routine use of a grading system for chromophobe renal cell carcinoma should not be used.
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Affiliation(s)
- A Pérez-Pedrosa
- Servicio de Anatomía Patológica, Hospital Xeral-Cíes, Complejo Hospitalario Universitario de Vigo, Vigo, Pontevedra, España.
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Ryu YJ, Cho TJ, Lee DS, Choi JY, Cho J. Phenotypic characterization and in vivo localization of human adipose-derived mesenchymal stem cells. Mol Cells 2013; 35:557-64. [PMID: 23677376 PMCID: PMC3887876 DOI: 10.1007/s10059-013-0112-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 04/18/2013] [Accepted: 04/19/2013] [Indexed: 12/31/2022] Open
Abstract
Human adipose-derived mesenchymal stem cells (hADMSCs) are a potential cell source for autologous cell therapy due to their regenerative ability. However, detailed cytological or phenotypic characteristics of these cells are still unclear. Therefore, we determined and compared cell size, morphology, ultrastructure, and immunohistochemical (IHC) expression profiles of isolated hADMSCs and cells located in human adipose tissues. We also characterized the localization of these cells in vivo. Light microscopy examination at low power revealed that hADMSCs acquired a spindle-shaped morphology after four passages. Additionally, high power views showed that these cells had various sizes, nuclear contours, and cytoplasmic textures. To further evaluate cell morphology, transmission electron microscopy was performed. hADMSCs typically had ultrastructural characteristics similar to those of primitive mesenchymal cells including a relatively high nuclear/cytosol ratio, prominent nucleoli, immature cytoplasmic organelles, and numerous filipodia. Some cells contained various numbers of lamellar bodies and lipid droplets. IHC staining demonstrated that PDGFR and CD10 were constitutively expressed in most hADMSCs regardless of passage number but expression levels of α-SMA, CD68, Oct4 and c-kit varied. IHC staining of adipose tissue showed that cells with immunophenotypic characteristics identical to those of hADMSCs were located mainly in the perivascular adventitia not in smooth muscle area. In summary, hADMSCs were found to represent a heterogeneous cell population with primitive mesenchymal cells that were mainly found in the perivascular adventitia. Furthermore, the cell surface markers would be CD10/PDGFR. To obtain defined cell populations for therapeutic purposes, further studies will be required to establish more specific isolation methods.
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Affiliation(s)
- Young-Joon Ryu
- Department of Pathology, College of medicine, Kangwon National University, Chuncheon 200-701,
Korea
| | - Tae-Jun Cho
- Department of Dental Regenerative Biotechnology, Seoul National University, Seoul 110-749,
Korea
- Dental Research Institute, School of Dentistry, Seoul National University, Seoul 110-749,
Korea
| | - Dong-Sup Lee
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 110-799,
Korea
| | - Jin-Young Choi
- Dental Research Institute, School of Dentistry, Seoul National University, Seoul 110-749,
Korea
- Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, Seoul 110-768,
Korea
| | - Jaejin Cho
- Department of Dental Regenerative Biotechnology, Seoul National University, Seoul 110-749,
Korea
- Dental Research Institute, School of Dentistry, Seoul National University, Seoul 110-749,
Korea
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42
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Szmyga MJ, Rybak EA, Nejat EJ, Banks EH, Whitney KD, Polotsky AJ, Heller DS, Meier UT. Quantification of nucleolar channel systems: uniform presence throughout the upper endometrial cavity. Fertil Steril 2013; 99:558-64. [PMID: 23137760 PMCID: PMC4074880 DOI: 10.1016/j.fertnstert.2012.10.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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: 06/25/2012] [Revised: 10/03/2012] [Accepted: 10/12/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVE To determine the prevalence of nucleolar channel systems (NCSs) by uterine region, applying continuous quantification. DESIGN Prospective clinical study. SETTING Tertiary care academic medical center. PATIENT(S) Forty-two naturally cycling women who underwent hysterectomy for benign indications. INTERVENTION(S) NCS presence was quantified by a novel method in six uterine regions-fundus, left cornu, right cornu, anterior body, posterior body, and lower uterine segment (LUS)-with the use of indirect immunofluorescence. MAIN OUTCOME MEASURE(S) Percentage of endometrial epithelial cells (EECs) with NCSs per uterine region. RESULT(S) NCS quantification was observer independent (intraclass correlation coefficient 0.96) and its intrasample variability low (coefficient of variation 0.06). Eleven of 42 hysterectomy specimens were midluteal, ten of which were analyzable with nine containing >5% EECs with NCSs in at least one region. The percentage of EECs with NCSs varied significantly between the LUS (6.1%; interquartile range [IQR] 3.0-9.9) and the upper five regions (16.9%; IQR 12.7-23.4), with fewer NCSs in the basal layer of the endometrium (17 ± 6%) versus the middle (46 ± 9%) and luminal layers (38 ± 9%) of all six regions. CONCLUSION(S) NCS quantification during the midluteal phase demonstrates uniform presence throughout the endometrial cavity, excluding the LUS, with a preference for the functional luminal layers. Our quantitative NCS evaluation provides a benchmark for future studies and further supports NCS presence as a potential marker for the window of implantation.
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Affiliation(s)
- Michael J. Szmyga
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY
| | - Eli A. Rybak
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY
- Department of Obstetrics & Gynecology and Women's Health, and Albert Einstein College of Medicine, Bronx, NY
| | - Edward J. Nejat
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY
- Department of Obstetrics & Gynecology and Women's Health, and Albert Einstein College of Medicine, Bronx, NY
| | - Erika H. Banks
- Department of Obstetrics & Gynecology and Women's Health, and Albert Einstein College of Medicine, Bronx, NY
| | | | - Alex J. Polotsky
- Department of Obstetrics & Gynecology and Women's Health, and Albert Einstein College of Medicine, Bronx, NY
| | - Debra S. Heller
- Department of Pathology, UMDNJ – New Jersey Medical School, Newark, NJ
| | - U. Thomas Meier
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY
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43
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Korshikov II, Tkacheva IA, Privalikhin SN. [Cytogenetic abnormalities in seedlings of Norway spruce (Picea abies (L.) Karst.) from the natural populations and introduction plantation]. Tsitol Genet 2012; 46:21-27. [PMID: 23342645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Comparative studies of the frequency and spectrum of pathological mitosis (PM), as well as of nucleoli number in the interphase cells of seedling roots have been performed in two natural populations of Norway spruce (Picea abies (L.) Karst.) of Ukrainian Polesie and introduction plantation in the Donbass. Low levels of PM in the seed progeny populations (0.32-0.38%) and slightly higher in the progeny plantation (0.40%) have been installed. Number of nucleoli was slightly higher in the plants of natural populations (5.35-5.85) than that of the plantation (4.95). The frequency of PM in the offspring of low-heterozygous plants was higher (0.43%) than in highly heterozygous individuals (0.28%).
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44
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Abstract
Mitosis in the amebo-flagellate Naegleria pringsheimi is acentrosomal and closed (the nuclear membrane does not break down). The large central nucleolus, which occupies about 20% of the nuclear volume, persists throughout the cell cycle. At mitosis, the nucleolus divides and moves to the poles in association with the chromosomes. The structure of the mitotic spindle and its relationship to the nucleolus are unknown. To identify the origin and structure of the mitotic spindle, its relationship to the nucleolus and to further understand the influence of persistent nucleoli on cellular division in acentriolar organisms like Naegleria, three-dimensional reconstructions of the mitotic spindle and nucleolus were carried out using confocal microscopy. Monoclonal antibodies against three different nucleolar regions and α-tubulin were used to image the nucleolus and mitotic spindle. Microtubules were restricted to the nucleolus beginning with the earliest prophase spindle microtubules. Early spindle microtubules were seen as short rods on the surface of the nucleolus. Elongation of the spindle microtubules resulted in a rough cage of microtubules surrounding the nucleolus. At metaphase, the mitotic spindle formed a broad band completely embedded within the nucleolus. The nucleolus separated into two discreet masses connected by a dense band of microtubules as the spindle elongated. At telophase, the distal ends of the mitotic spindle were still completely embedded within the daughter nucleoli. Pixel by pixel comparison of tubulin and nucleolar protein fluorescence showed 70% or more of tubulin co-localized with nucleolar proteins by early prophase. These observations suggest a model in which specific nucleolar binding sites for microtubules allow mitotic spindle formation and attachment. The fact that a significant mass of nucleolar material precedes the chromosomes as the mitotic spindle elongates suggests that spindle elongation drives nucleolar division.
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Affiliation(s)
- Charles J Walsh
- Department of Biological Science, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
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45
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Leonova OG, Karadzhian BP, Ivlev IF, Ivanova IL, Popenko VI. [Study of the positional relationship of nucleolar chromatin and nucleolar compartments in somatic nuclei OPF the ciliate Didinium nasutum]. Mol Biol (Mosk) 2012; 46:242-250. [PMID: 22670520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We showed earlier that nucleoli in interphase ciliates Didinium nasutum, appearing on single ultrathin sections as individual structures, actually are parts of more complex network-like structures in which fibrillar component is located on periphery, and granular--in the central part of a nucleolus. It is known, that nucleolar organizers in D. nasutum are represented by chromatin bodies connected with nucleoli. In this work we used 3D reconstruction on the basis of serial ultrathin sections to study localization of chromatin bodies which by morphological criteria might correspond to nucleolar organizers. Our data showed, that all such chromatin bodies settled down outside of nucleoli, near the periphery of fibrillar component. Even those chromatin bodies which on single sections looked completely surrounded by fibrillar nucleolar component, actually settled down in fibrillar component cavities open to nucleoplasm. Analysis of distribution of nucleolar chromatin bodies allowed us to conclude that activity in different parts of interphase complex network-like nucleoli of D. nasutum is approximately the same.
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46
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Alliegro MC, Hartson S, Alliegro MA. Composition and dynamics of the nucleolinus, a link between the nucleolus and cell division apparatus in surf clam (Spisula) oocytes. J Biol Chem 2012; 287:6702-13. [PMID: 22219192 PMCID: PMC3307295 DOI: 10.1074/jbc.m111.288506] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [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: 08/02/2011] [Revised: 12/27/2011] [Indexed: 11/06/2022] Open
Abstract
The nucleolinus is a little-known cellular structure, discovered over 150 years ago (Agassiz, L. (1857) Contributions to the Natural History of the United States of America, First Monograph, Part IIL, Little, Brown and Co., Boston) and thought by some investigators in the late 19th to mid-20th century to function in the formation of the centrosomes or spindle. A role for the nucleolinus in formation of the cell division apparatus has recently been confirmed in oocytes of the surf clam, Spisula solidissima (Alliegro, M. A., Henry, J. J., and Alliegro, M. C. (2010) Proc. Natl. Acad. Sci. U.S.A. 107, 13718-13723). However, we know so little about the composition and dynamics of this compartment, it is difficult to construct mechanistic hypotheses or even to be sure that prior reports were describing analogous structures in the cells of mammals, amphibians, plants, and other organisms where it was observed. Surf clam oocytes are an attractive model to approach this problem because the nucleolinus is easily visible by light microscopy, making it accessible by laser microsurgery as well as isolation by common cell fractionation techniques. In this report, we analyze the macromolecular composition of isolated Spisula nucleolini and examine the relationship of this structure to the nucleolus and cell division apparatus. Analysis of nucleolinar RNA and protein revealed a set of molecules that overlaps with but is nevertheless distinct from the nucleolus. The proteins identified were primarily ones involved in nucleic acid metabolism and cell cycle regulation. Monoclonal antibodies generated against isolated nucleolini revealed centrosomal forerunners in the oocyte cytoplasm. Finally, induction of damage to the nucleolinus by laser microsurgery altered the trafficking of α- and γ-tubulin after fertilization. These observations strongly support a role for the nucleolinus in cell division and represent our first clues regarding mechanism.
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Affiliation(s)
- Mark C. Alliegro
- From the Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, Massachusetts 02543 and
| | - Steven Hartson
- the Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74078
| | - Mary Anne Alliegro
- From the Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, Massachusetts 02543 and
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47
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Roselló-Lletí E, Rivera M, Cortés R, Azorín I, Sirera R, Martínez-Dolz L, Hove L, Cinca J, Lago F, González-Juanatey JR, Salvador A, Portolés M. Influence of heart failure on nucleolar organization and protein expression in human hearts. Biochem Biophys Res Commun 2012; 418:222-8. [PMID: 22244875 DOI: 10.1016/j.bbrc.2011.12.151] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 12/31/2011] [Indexed: 10/14/2022]
Abstract
We investigate for the first time the influence of heart failure (HF) on nucleolar organization and proteins in patients with ischemic (ICM) or dilated cardiomyopathy (DCM). A total of 71 human hearts from ICM (n=38) and DCM (n=27) patients, undergoing heart transplantation and control donors (n=6), were analysed by western-blotting, RT-PCR and cell biology methods. When we compared protein levels according to HF etiology, nucleolin was increased in both ICM (117%, p<0.05) and DCM (141%, p<0.01). Moreover, mRNA expression were also upregulated in ICM (1.46-fold, p<0.05) and DCM (1.70-fold, p<0.05. Immunofluorescence studies showed that the highest intensity of nucleolin was into nucleolus (p<0.0001), and it was increased in pathological hearts (p<0.0001). Ultrastructure analysis by electron microscopy showed an increase in the nucleus and nucleolus size in ICM (17%, p<0.05 and 131%, p<0.001) and DCM (56%, p<0.01 and 69%, p<0.01). Nucleolar organization was influenced by HF irrespective of etiology, increasing fibrillar centers (p<0.001), perinucleolar chromatin (p<0.01) and dense fibrillar components (p<0.01). Finally, left ventricular function parameters were related with nucleolin levels in ischemic hearts (p<0.0001). The present study demonstrates that HF influences on morphology and organization of nucleolar components, revealing changes in the expression and in the levels of nucleolin protein.
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Affiliation(s)
- Esther Roselló-Lletí
- Cardiocirculatory Unit, Research Center, Hospital Universitario La Fe, Valencia, Spain
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Freitas VS, dos Santos JN, Oliveira MC, Santos PPDA, Freitas RDA, de Souza LB. Intraoral granular cell tumors: clinicopathologic and immunohistochemical study. Quintessence Int 2012; 43:135-142. [PMID: 22257875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To describe a case series of intraoral granular cell tumors in terms of clinical, histologic, and immunohistochemical features. METHOD AND MATERIALS Nine cases of intraoral granular cell tumors were described in terms of clinical features (patient sex and age, anatomical location, size, type, time to clinical progression, and lesion treatment), histologic features (necrosis, spindling, vesicular nuclei with large nucleoli, increased mitotic activity, high nuclear to cytoplasmic ratio, and pleomorphism) and immunohistochemical features using S-100, CD68, neurofilament protein, desmin, and galectin-1. RESULTS Studied patients were mostly women with a mean age of 32 years. Lesions arose as solitary nodules on the tongue, with size ranging from 0.1 to 3.0 cm. Mean time to evolution was 21.83 months. All cases were treated by surgical excision. Two cases were classified as atypical and seven as benign. All cases presented immunoreactivity for S-100, CD68, and galectin-1, and there was no reactivity for desmin and neurofilament protein. CONCLUSION General practitioners should consider granular cell tumors during the differential diagnosis of nodular lesions on the tongue. Results suggest that histologic criteria may be used to distinguish between benign and atypical intraoral granular cell tumors. Finally, analysis of the clinical profile and the use of immunohistochemical markers may facilitate diagnosis and clarify the histogenesis of these lesions.
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Affiliation(s)
- Valéria Souza Freitas
- Oral Pathology Graduate Program, Department of Dentistry, Federal University of Rio Grande do Norte, Natal, Brazil
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Boamah EK, Kotova E, Garabedian M, Jarnik M, Tulin AV. Poly(ADP-Ribose) polymerase 1 (PARP-1) regulates ribosomal biogenesis in Drosophila nucleoli. PLoS Genet 2012; 8:e1002442. [PMID: 22242017 PMCID: PMC3252306 DOI: 10.1371/journal.pgen.1002442] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [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: 06/09/2011] [Accepted: 11/14/2011] [Indexed: 11/18/2022] Open
Abstract
Poly(ADP-ribose) polymerase 1 (PARP1), a nuclear protein, utilizes NAD to synthesize poly(AD-Pribose) (pADPr), resulting in both automodification and the modification of acceptor proteins. Substantial amounts of PARP1 and pADPr (up to 50%) are localized to the nucleolus, a subnuclear organelle known as a region for ribosome biogenesis and maturation. At present, the functional significance of PARP1 protein inside the nucleolus remains unclear. Using PARP1 mutants, we investigated the function of PARP1, pADPr, and PARP1-interacting proteins in the maintenance of nucleolus structure and functions. Our analysis shows that disruption of PARP1 enzymatic activity caused nucleolar disintegration and aberrant localization of nucleolar-specific proteins. Additionally, PARP1 mutants have increased accumulation of rRNA intermediates and a decrease in ribosome levels. Together, our data suggests that PARP1 enzymatic activity is required for targeting nucleolar proteins to the proximity of precursor rRNA; hence, PARP1 controls precursor rRNA processing, post-transcriptional modification, and pre-ribosome assembly. Based on these findings, we propose a model that explains how PARP1 activity impacts nucleolar functions and, consequently, ribosomal biogenesis. Ribosome assembly happens primarily in the subnuclear organelle nucleolus. In the nucleolus, ribosomes are assembled into a multmeric complex, composed of rRNA and ribosomal proteins. Although a lot is known about ribosomes and how they function, very little is known about the mechanism that facilitates the assembly of these multimeric protein complexes in the nucleolus. Here, we provide evidence that a nuclear protein, PARP1, primarily known for its DNA damage repair and transcriptional activities, also plays a critical role in the assembly of ribosomes. Using the Drosophila model system, we show that PARP1 localization within the nucleolus impacts such nucleolar activities as rRNA processing and ribosome biogenesis. We show that, when PARP1 activity is disrupted, nucleolar proteins that normally co-localize under wild-type conditions disperse into the nucleoplasm and do not show any co-localization. We also show that some nucleolar proteins, essential for rRNA processing, also interact with pADPr, which keeps these proteins close to precursor rRNA. When PARP1 activity was disrupted, we observed precursors rRNA accumulation and a concomitant decrease in the levels of ribosomes. Together, our data suggest a novel activity for PARP1 and highlight a potential mechanism associated with ribosome biogenesis in the nucleolus.
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Affiliation(s)
- Ernest K. Boamah
- Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Elena Kotova
- Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Mikael Garabedian
- Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Michael Jarnik
- Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Alexei V. Tulin
- Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Chistiakova LV, Miteva OA, Frolov AO. [Morphology of Mastigamoeba aspera Schulze, 1875 (Archamoebae, Pelobiontida)]. Tsitologiia 2012; 54:58-65. [PMID: 22567901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The morphology of Mastigamoeba aspera, a type species of the genus Mastigamoeba Schulze, 1875, has been investigated at the light- and electron-microscopical level. Motile individuals are oval or peach-shaped. Motile flagella is situated at the anterior end of uninucleate cells. During locomotion, the surface of mastigamoebes forms many conical or finger-shaped hyaline pseudopodia, wereas bulbous uroid is often formed at the posterior end of the cell. Micropopulations of M. aspera consist of uninucleate flagellate forms as well as multinucleate aflagellate ones. There is a thick layer ofglycocalix on the cell surface where many rod-shaped bacterial ectobionts live. The nucleus is vesicular with spherical central nucleolus. The flagellar apparatus of M. aspera is connected with nucleus to form so called kariomastigont. A single kinetosome is associated with many radial microtubules and a lateral root. A distinct microtubule organization centre (MTOC) is situated at the basal part of the kinetosome. Microtubules of the nuclear cone are connected with the MTOC. This microtubules take part in the formation of kariomastigont. The axoneme has a standart set of microtubules 9(2)+2. Digestive vacuoles are the main component of the cytoplasm of M. aspera. Beside, many light-difracted granules and glycogen bodies were found in the cells. Mitochondria, dictyosomes of the Golgi apparatus and microbodies were not revealed in the cytoplasm of M. aspera.
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