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Santos WFS, Cantuária APDC, Félix DDC, Guimarães NC, de Melo ICS. Complex patterns on HEp-2 indirect immunofluorescence assay in a large sample referred for anti-cell autoantibodies detection. Front Immunol 2024; 14:1256526. [PMID: 38283335 PMCID: PMC10811459 DOI: 10.3389/fimmu.2023.1256526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 12/19/2023] [Indexed: 01/30/2024] Open
Abstract
Introduction The combination of patterns is a frequent and challenging situation in the daily laboratory routine of autoantibodies testing using HEp-2 cells indirect immunofluorescence assay (HEp-2-IFA). Recently, the Brazilian Consensus on Autoantibodies (BCA) named these combinations as complex patterns (CPs) and organized them into 3 subtypes: multiple, mixed, and composite. This study aimed to describe the most frequent combinations of HEp-2-IIF patterns according to this new nomenclature. Methods Routine HEp-2-IFA results reported in January and June 2017 were reviewed using the new BCA classification. Visual pattern recognition was performed by experts on HEp-2-IFA readings, using the International Consensus on Antinuclear Antibodies (ANA) Patterns (ICAP) and BCA recommendations. Results 54,990 serum samples from different patients were tested for ANA-HEp-2, and 11,478 (20.9%) were positive at a titer ≥ 1/80. Among these positive samples, 1,111 (9.7%) displayed CPs, divided into 95 different combinations. A higher proportion of CPs was observed in the pediatric age group. Multiple, mixed, and composite patterns were present in 85.3, 5.4, and 9.5% of the samples, respectively. In the multiple/mixed pattern group (n=1,005), double, triple, and quadruple combinations (ICAP/BCA codes) were observed in 97.7%, 2.2%, and 0.1%, respectively. The double nuclear pattern was the most prevalent combination observed (67.6%). The most common CPs registered were AC-4 (nuclear fine speckled) + AC-6,7 (nuclear discrete dots) (n=264); AC-2 (nuclear dense fine speckled) + AC-6,7 (n=201); AC-4+AC-8,9,10 (nucleolar) (n=129); and AC-3 (centromere)+AC-4 (n=124). All of these combinations were in the multiple subgroup. Conclusion Almost 10% of positive results in the HEp-2 procedure displayed CPs. Among the 3 subtypes of CPs proposed, the multiple pattern was the most prevalent, especially in the pediatric population. The AC-4, AC-2, and AC-6,7 were the most prevalent single patterns observed in the combinations described in this study. There was a significant association between age and the prevalence of most combined patterns. The AC-4+AC-6,7 combination was the most prevalent complex pattern detected regardless of the age group. The AC-2+AC-6,7 was more prevalent in younger individuals. The concepts involved in the CPs definition should add value to the reading and interpretation of the HEp-2-IIF assay.
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Staněk D. Coilin and Cajal bodies. Nucleus 2023; 14:2256036. [PMID: 37682044 PMCID: PMC10494742 DOI: 10.1080/19491034.2023.2256036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/09/2023] Open
Abstract
The nucleus of higher eukaryotes contains a number of structures that concentrate specific biomolecules and play distinct roles in nuclear metabolism. In recent years, the molecular mechanisms controlling their formation have been intensively studied. In this brief review, I focus on coilin and Cajal bodies. Coilin is a key scaffolding protein of Cajal bodies that is evolutionarily conserved in metazoans. Cajal bodies are thought to be one of the archetypal nuclear structures involved in the metabolism of several short non-coding nuclear RNAs. Yet surprisingly little is known about the structure and function of coilin, and a comprehensive model to explain the origin of Cajal bodies is also lacking. Here, I summarize recent results on Cajal bodies and coilin and discuss them in the context of the last three decades of research in this field.
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Affiliation(s)
- David Staněk
- Laboratory of RNA Biology, Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
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Lettin L, Erbay B, Blair GE. Viruses and Cajal Bodies: A Critical Cellular Target in Virus Infection? Viruses 2023; 15:2311. [PMID: 38140552 PMCID: PMC10747631 DOI: 10.3390/v15122311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/24/2023] Open
Abstract
Nuclear bodies (NBs) are dynamic structures present in eukaryotic cell nuclei. They are not bounded by membranes and are often considered biomolecular condensates, defined structurally and functionally by the localisation of core components. Nuclear architecture can be reorganised during normal cellular processes such as the cell cycle as well as in response to cellular stress. Many plant and animal viruses target their proteins to NBs, in some cases triggering their structural disruption and redistribution. Although not all such interactions have been well characterised, subversion of NBs and their functions may form a key part of the life cycle of eukaryotic viruses that require the nucleus for their replication. This review will focus on Cajal bodies (CBs) and the viruses that target them. Since CBs are dynamic structures, other NBs (principally nucleoli and promyelocytic leukaemia, PML and bodies), whose components interact with CBs, will also be considered. As well as providing important insights into key virus-host cell interactions, studies on Cajal and associated NBs may identify novel cellular targets for development of antiviral compounds.
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Affiliation(s)
- Lucy Lettin
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK (B.E.)
| | - Bilgi Erbay
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK (B.E.)
- Moleküler Biyoloji ve Genetik Bölümü, Fen Fakültesi, Van Yuzuncu Yil University, Van 65140, Türkiye
| | - G. Eric Blair
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK (B.E.)
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Taliansky ME, Love AJ, Kołowerzo-Lubnau A, Smoliński DJ. Cajal bodies: Evolutionarily conserved nuclear biomolecular condensates with properties unique to plants. THE PLANT CELL 2023; 35:3214-3235. [PMID: 37202374 PMCID: PMC10473218 DOI: 10.1093/plcell/koad140] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/20/2023]
Abstract
Proper orchestration of the thousands of biochemical processes that are essential to the life of every cell requires highly organized cellular compartmentalization of dedicated microenvironments. There are 2 ways to create this intracellular segregation to optimize cellular function. One way is to create specific organelles, enclosed spaces bounded by lipid membranes that regulate macromolecular flux in and out of the compartment. A second way is via membraneless biomolecular condensates that form due to to liquid-liquid phase separation. Although research on these membraneless condensates has historically been performed using animal and fungal systems, recent studies have explored basic principles governing the assembly, properties, and functions of membraneless compartments in plants. In this review, we discuss how phase separation is involved in a variety of key processes occurring in Cajal bodies (CBs), a type of biomolecular condensate found in nuclei. These processes include RNA metabolism, formation of ribonucleoproteins involved in transcription, RNA splicing, ribosome biogenesis, and telomere maintenance. Besides these primary roles of CBs, we discuss unique plant-specific functions of CBs in RNA-based regulatory pathways such as nonsense-mediated mRNA decay, mRNA retention, and RNA silencing. Finally, we summarize recent progress and discuss the functions of CBs in responses to pathogen attacks and abiotic stresses, responses that may be regulated via mechanisms governed by polyADP-ribosylation. Thus, plant CBs are emerging as highly complex and multifunctional biomolecular condensates that are involved in a surprisingly diverse range of molecular mechanisms that we are just beginning to appreciate.
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Affiliation(s)
| | - Andrew J Love
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Agnieszka Kołowerzo-Lubnau
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland
| | - Dariusz Jan Smoliński
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland
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5
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Wu S, Chen J, Teo BHD, Wee SYK, Wong MHM, Cui J, Chen J, Leong KP, Lu J. The axis of complement C1 and nucleolus in antinuclear autoimmunity. Front Immunol 2023; 14:1196544. [PMID: 37359557 PMCID: PMC10288996 DOI: 10.3389/fimmu.2023.1196544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/19/2023] [Indexed: 06/28/2023] Open
Abstract
Antinuclear autoantibodies (ANA) are heterogeneous self-reactive antibodies that target the chromatin network, the speckled, the nucleoli, and other nuclear regions. The immunological aberration for ANA production remains partially understood, but ANA are known to be pathogenic, especially, in systemic lupus erythematosus (SLE). Most SLE patients exhibit a highly polygenic disease involving multiple organs, but in rare complement C1q, C1r, or C1s deficiencies, the disease can become largely monogenic. Increasing evidence point to intrinsic autoimmunogenicity of the nuclei. Necrotic cells release fragmented chromatins as nucleosomes and the alarmin HMGB1 is associated with the nucleosomes to activate TLRs and confer anti-chromatin autoimmunogenecity. In speckled regions, the major ANA targets Sm/RNP and SSA/Ro contain snRNAs that confer autoimmunogenecity to Sm/RNP and SSA/Ro antigens. Recently, three GAR/RGG-containing alarmins have been identified in the nucleolus that helps explain its high autoimmunogenicity. Interestingly, C1q binds to the nucleoli exposed by necrotic cells to cause protease C1r and C1s activation. C1s cleaves HMGB1 to inactive its alarmin activity. C1 proteases also degrade many nucleolar autoantigens including nucleolin, a major GAR/RGG-containing autoantigen and alarmin. It appears that the different nuclear regions are intrinsically autoimmunogenic by containing autoantigens and alarmins. However, the extracellular complement C1 complex function to dampen nuclear autoimmunogenecity by degrading these nuclear proteins.
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Affiliation(s)
- Shan Wu
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Immunology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Junjie Chen
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Immunology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Boon Heng Dennis Teo
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Immunology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Seng Yin Kelly Wee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Immunology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Ming Hui Millie Wong
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Immunology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Jianzhou Cui
- Immunology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Jinmiao Chen
- Immunology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore, Singapore
| | - Khai Pang Leong
- Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore, Singapore
| | - Jinhua Lu
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Immunology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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Voss PG, Wang JL. Liquid-liquid phase separation: Galectin-3 in nuclear speckles and ribonucleoprotein complexes. Exp Cell Res 2023; 427:113571. [PMID: 37003559 DOI: 10.1016/j.yexcr.2023.113571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/19/2023] [Accepted: 03/24/2023] [Indexed: 04/03/2023]
Abstract
Nuclear speckles are subcellular structures originally characterized by punctate immunofluorescence staining of the monoclonal antibody SC35, which recognizes an epitope on SRRM2 (serine/arginine repetitive matrix protein 2) and Sfrs2, a member of the SR (serine/arginine-rich) family of splicing factors. Galectin-3 co-localizes with SC35 in nuclear speckles, which represent one group of nuclear bodies that include the nucleolus, Cajal bodies and gems, paraspeckles, etc. Although they appear to have well-delineated physical boundaries, these nuclear bodies are not membrane-bound structures but represent macromolecular assemblies arising from a phenomenon called liquid-liquid phase separation. There has been much recent interest in liquid phase condensation as a newly recognized mechanism by which a cell can organize and compartmentalize subcellular structures with distinct composition. The punctate/speckled staining of galectin-3 with SC3 demonstrates their co-localization in a phase-separated body in vivo, under conditions endogenous to the cell. The purpose of the present review is to summarize the studies that document three key features of galectin-3 for its localization in liquid phase condensates: (a) an intrinsically disordered domain; (b) oligomer formation for multivalent binding; and (c) association with RNA and ribonucleoprotein complexes.
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Affiliation(s)
- Patricia G Voss
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - John L Wang
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA.
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7
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Kim C, Kwon Y, Jeong J, Kang M, Lee GS, Moon JH, Lee HJ, Park YI, Choi G. Phytochrome B photobodies are comprised of phytochrome B and its primary and secondary interacting proteins. Nat Commun 2023; 14:1708. [PMID: 36973259 PMCID: PMC10042835 DOI: 10.1038/s41467-023-37421-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 03/16/2023] [Indexed: 03/29/2023] Open
Abstract
Phytochrome B (phyB) is a plant photoreceptor that forms a membraneless organelle called a photobody. However, its constituents are not fully known. Here, we isolated phyB photobodies from Arabidopsis leaves using fluorescence-activated particle sorting and analyzed their components. We found that a photobody comprises ~1,500 phyB dimers along with other proteins that could be classified into two groups: The first includes proteins that directly interact with phyB and localize to the photobody when expressed in protoplasts, while the second includes proteins that interact with the first group proteins and require co-expression of a first-group protein to localize to the photobody. As an example of the second group, TOPLESS interacts with PHOTOPERIODIC CONTROL OF HYPOCOTYL 1 (PCH1) and localizes to the photobody when co-expressed with PCH1. Together, our results support that phyB photobodies include not only phyB and its primary interacting proteins but also its secondary interacting proteins.
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Affiliation(s)
- Chanhee Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Korea
| | - Yongmin Kwon
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Korea
| | - Jaehoon Jeong
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Korea
| | - Minji Kang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Korea
| | - Ga Seul Lee
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Korea
- College of Pharmacy, Chungbuk National University, Cheongju, Chungbuk, 28160, Korea
| | - Jeong Hee Moon
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Korea
| | - Hyo-Jun Lee
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Korea
| | - Youn-Il Park
- Department of Biological Sciences, Chungnam National University, Daejeon, 34134, Korea
| | - Giltsu Choi
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Korea.
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8
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Cruvinel WDM, Andrade LEC, Dellavance A, Ximenes AC, Bichara CDA, Mangueira CLP, Bonfá E, de Almeida Brito F, Mariz HA, Dos Anjos LME, Pasoto SG, Valim V, Dos Santos WFS, Gomes CM, Neves RA, Francescantonio PLC. VI Brazilian consensus guidelines for detection of anti-cell autoantibodies on HEp-2 cells. Adv Rheumatol 2022; 62:34. [PMID: 36071498 DOI: 10.1186/s42358-022-00266-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/24/2022] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND The VI Brazilian Consensus on Autoantibodies against HEp-2 cells for determination of autoantibodies against cellular constituents on HEp-2 cells was held on September, 2019, in Fortaleza (CE, Brazil). The guidelines in this edition were formulated by the group of Brazilian experts discussing the classification of complex patterns, the classification of the nuclear discrete dots (few and multiple), the identification of the discrete fine speckled pattern (AC-4a) and improvements on the ANA report. MAINBODY Sixteen Brazilian researchers and experts from universities and clinical laboratories representing the various geographical regions of Brazil participated in the meeting. Four main topics were discussed: (1) How to classify patterns with fluorescence in more than one cell compartment considering three relevant categoris: composite patterns, mixed patterns and multiple patterns; (2) The splitting of the discrete nuclear dots pattern into the multiple discrete nuclear dots (AC-6) and few discrete nuclear dots (AC-7) patterns, respectively; (3) Inclusion of a novel nuclear pattern characterized by discrete fine speckled pattern highly associated with antibodies to SS-A/Ro60, classified as AC-4a. In addition, adjustments on the Brazilian Consensus nomenclature were implemented aiming to harmonize the designation of some patterns with the International Consensus on ANA Patterns (ICAP). Furthermore, the designations of the PCNA-like pattern (AC-13), CENP-F-like pattern (AC-14) and Topo I-like pattern (AC-29) were adjusted in accordance to ICAP. Finally, there was a recommendation for adjustment in the test report in order to address the status of nuclear envelope staining. For all topics, the aim was to establish specific guidelines for laboratories and clinicians. All recommendations were based on consensus among participants. All recommendations from the V Consensus were maintained and there was relevant progress in the BCA/HEp-2 guidelines and further harmonization with ICAP. CONCLUSION The VI BCA/HEp-2 edition was successful in establishing important recommendations regarding the classification of complex patterns, in supporting the identification of a novel pattern within the AC-4 group and in the harmonization process with the ICAP terminology.
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Affiliation(s)
- Wilson de Melo Cruvinel
- School of Medical and Life Sciences, Escola de Ciências Médicas e da Vida, Pontifícia Universidade Católica de Goiás (PUC GOIÁS), Avenida Universitária 1.440, Setor Universitário, Goiânia, GO, 74605-010, Brazil.
| | - Luis Eduardo Coelho Andrade
- Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil
| | - Alessandra Dellavance
- Immunology Division, Fleury Medicine and Health Laboratories, São Paulo, Brazil.,Divisão de Pesquisa, Inovação e Desenvolvimento, Fleury Medicina E Saúde, São Paulo, SP, Brazil
| | | | - Carlos David Araújo Bichara
- Centro Universitário Metropolitano da Amazônia (UNIFAMAZ), Amaral Costa Medicina Diagnóstica, Belém, PA, Brazil
| | | | - Eloísa Bonfá
- Faculdade de Medicina, Hospital das Clinicas HCFMUSP, Universidade de Sao Paulo, São Paulo, SP, Brazil
| | - Fabiano de Almeida Brito
- Department of Clinical Pathology, School of Medicine, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.,Hermes Pardini Group, Vespasiano, MG, Brazil
| | - Henrique Ataíde Mariz
- Rheumatology Department, Universidade Federal de Pernambuco (UFPE), Recife, PE, Brazil
| | | | - Sandra Gofinet Pasoto
- Serviço de Reumatologia e Laboratório de Autoimunidade da Divisão de Laboratório Central do Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
| | - Valeria Valim
- Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil
| | | | - Clayson Moura Gomes
- School of Medical and Life Sciences, Escola de Ciências Médicas e da Vida, Pontifícia Universidade Católica de Goiás (PUC GOIÁS), Avenida Universitária 1.440, Setor Universitário, Goiânia, GO, 74605-010, Brazil
| | - Roberpaulo Anacleto Neves
- School of Medical and Life Sciences, Escola de Ciências Médicas e da Vida, Pontifícia Universidade Católica de Goiás (PUC GOIÁS), Avenida Universitária 1.440, Setor Universitário, Goiânia, GO, 74605-010, Brazil
| | - Paulo Luiz Carvalho Francescantonio
- School of Medical and Life Sciences, Escola de Ciências Médicas e da Vida, Pontifícia Universidade Católica de Goiás (PUC GOIÁS), Avenida Universitária 1.440, Setor Universitário, Goiânia, GO, 74605-010, Brazil
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Muñoz-Díaz E, Sáez-Vásquez J. Nuclear dynamics: Formation of bodies and trafficking in plant nuclei. FRONTIERS IN PLANT SCIENCE 2022; 13:984163. [PMID: 36082296 PMCID: PMC9445803 DOI: 10.3389/fpls.2022.984163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 08/04/2022] [Indexed: 06/01/2023]
Abstract
The existence of the nucleus distinguishes prokaryotes and eukaryotes. Apart from containing most of the genetic material, the nucleus possesses several nuclear bodies composed of protein and RNA molecules. The nucleus is separated from the cytoplasm by a double membrane, regulating the trafficking of molecules in- and outwards. Here, we investigate the composition and function of the different plant nuclear bodies and molecular clues involved in nuclear trafficking. The behavior of the nucleolus, Cajal bodies, dicing bodies, nuclear speckles, cyclophilin-containing bodies, photobodies and DNA damage foci is analyzed in response to different abiotic stresses. Furthermore, we research the literature to collect the different protein localization signals that rule nucleocytoplasmic trafficking. These signals include the different types of nuclear localization signals (NLSs) for nuclear import, and the nuclear export signals (NESs) for nuclear export. In contrast to these unidirectional-movement signals, the existence of nucleocytoplasmic shuttling signals (NSSs) allows bidirectional movement through the nuclear envelope. Likewise, nucleolar signals are also described, which mainly include the nucleolar localization signals (NoLSs) controlling nucleolar import. In contrast, few examples of nucleolar export signals, called nucleoplasmic localization signals (NpLSs) or nucleolar export signals (NoESs), have been reported. The existence of consensus sequences for these localization signals led to the generation of prediction tools, allowing the detection of these signals from an amino acid sequence. Additionally, the effect of high temperatures as well as different post-translational modifications in nuclear and nucleolar import and export is discussed.
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Affiliation(s)
- Eduardo Muñoz-Díaz
- Centre National de la Recherche Scientifique (CNRS), Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France
- Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France
| | - Julio Sáez-Vásquez
- Centre National de la Recherche Scientifique (CNRS), Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France
- Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France
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10
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Belmont AS. Nuclear Compartments: An Incomplete Primer to Nuclear Compartments, Bodies, and Genome Organization Relative to Nuclear Architecture. Cold Spring Harb Perspect Biol 2022; 14:a041268. [PMID: 34400557 PMCID: PMC9248822 DOI: 10.1101/cshperspect.a041268] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This work reviews nuclear compartments, defined broadly to include distinct nuclear structures, bodies, and chromosome domains. It first summarizes original cytological observations before comparing concepts of nuclear compartments emerging from microscopy versus genomic approaches and then introducing new multiplexed imaging approaches that promise in the future to meld both approaches. I discuss how previous models of radial distribution of chromosomes or the binary division of the genome into A and B compartments are now being refined by the recognition of more complex nuclear compartmentalization. The poorly understood question of how these nuclear compartments are established and maintained is then discussed, including through the modern perspective of phase separation, before moving on to address possible functions of nuclear compartments, using the possible role of nuclear speckles in modulating gene expression as an example. Finally, the review concludes with a discussion of future questions for this field.
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Affiliation(s)
- Andrew S Belmont
- Department of Cell and Developmental Biology, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
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11
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Basello DA, Matera AG, Staněk D. A point mutation in human coilin prevents Cajal body formation. J Cell Sci 2022; 135:274900. [PMID: 35356988 PMCID: PMC9080554 DOI: 10.1242/jcs.259587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 03/20/2022] [Indexed: 11/20/2022] Open
Abstract
Coilin is a conserved protein essential for integrity of nuclear membrane-less inclusions called Cajal bodies. Here, we report an amino-acid substitution (p.K496E) found in a widely-used human EGFP-coilin construct that has a dominant negative effect on Cajal body formation. We show that this coilin-K496E variant fails to rescue Cajal bodies in cells lacking endogenous coilin, whereas the wild-type construct restores Cajal bodies in mouse and human coilin-knockout cells. In cells containing endogenous coilin, both the wild-type and K496E variant proteins accumulate in Cajal bodies. However, high-level overexpression of coilin-K496E causes Cajal body disintegration. Thus, a mutation in the C-terminal region of human coilin can disrupt Cajal body assembly. Caution should be used when interpreting data from coilin plasmids that are derived from this variant (currently deposited at Addgene).
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Affiliation(s)
- Davide A Basello
- Institute of Molecular Genetics, Czech Academy of Science, Prague, Czech Republic.,Faculty of Science, Charles University, Prague, Czech Republic
| | - A Gregory Matera
- Integrative Program for Biological and Genome Sciences, and Department of Biology, University of North Carolina, Chapel Hill, USA
| | - David Staněk
- Institute of Molecular Genetics, Czech Academy of Science, Prague, Czech Republic
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12
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von Mühlen CA, Garcia-De La Torre I, Infantino M, Damoiseaux J, Andrade LEC, Carballo OG, Conrad K, Francescantonio PLC, Fritzler MJ, Herold M, Klotz W, de Melo Cruvinel W, Mimori T, Satoh M, Musset L, Chan EKL. How to report the antinuclear antibodies (anti-cell antibodies) test on HEp-2 cells: guidelines from the ICAP initiative. Immunol Res 2021; 69:594-608. [PMID: 34625914 DOI: 10.1007/s12026-021-09233-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 08/30/2021] [Indexed: 12/15/2022]
Abstract
Results of the anti-nuclear antibodies-indirect immunofluorescence assay (anti-cell antibodies test) on HEp-2 cell substrates should be communicated to clinicians in a standardized way, adding value to laboratory findings and helping with critical clinical decisions. This paper proposes a test report based on the practices informed by 118 laboratories in 68 countries, with recommendations from the International Consensus on ANA Patterns (ICAP) group. Major focus is placed on the report format containing endpoint titers, immunofluorescence patterns together with anti-cell (AC) nomenclature, remarks on follow-up or reflex testing, and possible other autoantibody associations. ISO 15,189 directives were integrated into the test report. Special situations addressed include serum screening dilutions and endpoint titers, relevance of immunofluorescence patterns with special attention to cytoplasmic patterns, mixed and compound patterns, and how to report different titers corresponding to multiple patterns or autoantibodies in the same sample. This paper suggests a subtitle for the HEp-2-IIFA, namely anti-cell antibodies test, which could gradually substitute the original outdated ANA nomenclature. This ICAP pro forma report represents a further step in harmonizing the way relevant clinical information could be provided by laboratories.
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Affiliation(s)
- Carlos Alberto von Mühlen
- Hospital Moinhos de Vento, Rheumatology Unit, Porto Alegre, Brazil. .,Consultant in Rheumatology and Clinical Pathology, San Diego, USA.
| | - Ignacio Garcia-De La Torre
- Department of Immunology and Rheumatology, Hospital General de Occidente, Universidad de Guadalajara, Guadalajara, Mexico
| | - Maria Infantino
- Immunology and Allergy Laboratory, San Giovanni Di Dio Hospital, Florence, Italy
| | - Jan Damoiseaux
- Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Luis E C Andrade
- Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.,Immunology Division, Fleury Medicine and Health Laboratories, São Paulo, Brazil
| | - Orlando Gabriel Carballo
- Laboratory of Immunology, Hospital Carlos G. Durand, Buenos Aires, Argentina.,Department of Microbiology and Immunology, Instituto Universitario del Hospital Italiano, Buenos Aires, Argentina
| | - Karsten Conrad
- Institute of Immunology, Technical University of Dresden, Dresden, Germany
| | | | - Marvin J Fritzler
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Manfred Herold
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | - Werner Klotz
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Tsuneyo Mimori
- Ijinkai Takeda General Hospital, and Department of Rheumatology and Clinical Immunology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Minoru Satoh
- Department of Clinical Nursing, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Lucile Musset
- Department of Immunology, Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - Edward K L Chan
- Department of Oral Biology, University of Florida, Gainesville, FL, USA
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13
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Duan N, Arroyo M, Deng W, Cardoso MC, Leonhardt H. Visualization and characterization of RNA-protein interactions in living cells. Nucleic Acids Res 2021; 49:e107. [PMID: 34313753 PMCID: PMC8501972 DOI: 10.1093/nar/gkab614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 05/14/2021] [Accepted: 07/07/2021] [Indexed: 12/26/2022] Open
Abstract
RNA–protein interactions are the structural and functional basis of significant numbers of RNA molecules. RNA–protein interaction assays though, still mainly depend on biochemical tests in vitro. Here, we establish a convenient and reliable RNA fluorescent three-hybrid (rF3H) method to detect/interrogate the interactions between RNAs and proteins in cells. A GFP tagged highly specific RNA trap is constructed to anchor the RNA of interest to an artificial or natural subcellular structure, and RNA–protein interactions can be detected and visualized by the enrichment of RNA binding proteins (RBPs) at these structures. Different RNA trapping systems are developed and detection of RNA–protein complexes at multiple subcellular structures are assayed. With this new toolset, interactions between proteins and mRNA or noncoding RNAs are characterized, including the interaction between a long noncoding RNA and an epigenetic modulator. Our approach provides a flexible and reliable method for the characterization of RNA–protein interactions in living cells.
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Affiliation(s)
- Ningjun Duan
- Department of Biology II, Ludwig Maximilians University Munich, Munich 81377, Germany.,Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Maria Arroyo
- Department of Biology, Technical University of Darmstadt, Darmstadt 64287, Germany
| | - Wen Deng
- Department of Biology II, Ludwig Maximilians University Munich, Munich 81377, Germany.,College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China
| | - M Cristina Cardoso
- Department of Biology, Technical University of Darmstadt, Darmstadt 64287, Germany
| | - Heinrich Leonhardt
- Department of Biology II, Ludwig Maximilians University Munich, Munich 81377, Germany
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14
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Wang Z, Wang X, Wang Y, Tang S, Feng C, Pan L, Lu Q, Tao Y, Xie Y, Wang Q, Tang Z. Transcriptomic Analysis of Gene Networks Regulated by U11 Small Nuclear RNA in Bladder Cancer. Front Genet 2021; 12:695597. [PMID: 34276798 PMCID: PMC8283811 DOI: 10.3389/fgene.2021.695597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/11/2021] [Indexed: 01/26/2023] Open
Abstract
Small nuclear RNA is a class of non-coding RNA that widely exist in the nucleus of eukaryotes. Accumulated evidences have shown that small nuclear RNAs are associated with the regulation of gene expression in various tumor types. To explore the gene expression changes and its potential effects mediated by U11 snRNA in bladder cancer cells, U11 snRNA knockout and overexpressed cell lines were constructed and further used to analyze the gene expression changes by RNA sequencing. The differentially expressed genes were found to be mainly enriched in tumor-related pathways both in the U11 knockout and overexpression cell lines, such as NF-kappa B signaling pathway, bladder cancer and PI3K-Akt signaling pathway. Furthermore, alternative splicing events were proposed to participate in the potential regulatory mechanism induced by the U11 knockout or overexpression. In conclusion, U11 may be involved in the regulation of gene expression in bladder cancer cells, which may provide a potentially new biomarker for clinical diagnosis and treatment of bladder cancer.
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Affiliation(s)
- Zhenxing Wang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, China.,Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Xi Wang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, China
| | - Yaobang Wang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, China
| | - Shaomei Tang
- Department of Gastroenterology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Chao Feng
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, China
| | - Lixin Pan
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, China
| | - Qinchen Lu
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, China
| | - Yuting Tao
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, China
| | - Yuanliang Xie
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, China.,Department of Urology, The Affiliated Cancer Hospital of Guangxi Medical University, Nanning, China
| | - Qiuyan Wang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, China
| | - Zhong Tang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, China.,School of Information and Management, Guangxi Medical University, Nanning, China
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15
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Drosophila to Explore Nucleolar Stress. Int J Mol Sci 2021; 22:ijms22136759. [PMID: 34201772 PMCID: PMC8267670 DOI: 10.3390/ijms22136759] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 01/29/2023] Open
Abstract
Nucleolar stress occurs when ribosome production or function declines. Nucleolar stress in stem cells or progenitor cells often leads to disease states called ribosomopathies. Drosophila offers a robust system to explore how nucleolar stress causes cell cycle arrest, apoptosis, or autophagy depending on the cell type. We provide an overview of nucleolar stress in Drosophila by depleting nucleolar phosphoprotein of 140 kDa (Nopp140), a ribosome biogenesis factor (RBF) in nucleoli and Cajal bodies (CBs). The depletion of Nopp140 in eye imaginal disc cells generates eye deformities reminiscent of craniofacial deformities associated with the Treacher Collins syndrome (TCS), a human ribosomopathy. We show the activation of c-Jun N-terminal Kinase (JNK) in Drosophila larvae homozygous for a Nopp140 gene deletion. JNK is known to induce the expression of the pro-apoptotic Hid protein and autophagy factors Atg1, Atg18.1, and Atg8a; thus, JNK is a central regulator in Drosophila nucleolar stress. Ribosome abundance declines upon Nopp140 loss, but unusual cytoplasmic granules accumulate that resemble Processing (P) bodies based on marker proteins, Decapping Protein 1 (DCP1) and Maternal expression at 31B (Me31B). Wild type brain neuroblasts (NBs) express copious amounts of endogenous coilin, but coilin levels decline upon nucleolar stress in most NB types relative to the Mushroom body (MB) NBs. MB NBs exhibit resilience against nucleolar stress as they maintain normal coilin, Deadpan, and EdU labeling levels.
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16
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Schilling M, Prusty AB, Boysen B, Oppermann FS, Riedel YL, Husedzinovic A, Rasouli H, König A, Ramanathan P, Reymann J, Erfle H, Daub H, Fischer U, Gruss OJ. TOR signaling regulates liquid phase separation of the SMN complex governing snRNP biogenesis. Cell Rep 2021; 35:109277. [PMID: 34161763 DOI: 10.1016/j.celrep.2021.109277] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 04/23/2021] [Accepted: 05/27/2021] [Indexed: 01/10/2023] Open
Abstract
The activity of the SMN complex in promoting the assembly of pre-mRNA processing UsnRNPs correlates with condensation of the complex in nuclear Cajal bodies. While mechanistic details of its activity have been elucidated, the molecular basis for condensation remains unclear. High SMN complex phosphorylation suggests extensive regulation. Here, we report on systematic siRNA-based screening for modulators of the capacity of SMN to condense in Cajal bodies and identify mTOR and ribosomal protein S6 kinase β-1 as key regulators. Proteomic analysis reveals TOR-dependent phosphorylations in SMN complex subunits. Using stably expressed or optogenetically controlled phospho mutants, we demonstrate that serine 49 and 63 phosphorylation of human SMN controls the capacity of the complex to condense in Cajal bodies via liquid-liquid phase separation. Our findings link SMN complex condensation and UsnRNP biogenesis to cellular energy levels and suggest modulation of TOR signaling as a rational concept for therapy of the SMN-linked neuromuscular disorder spinal muscular atrophy.
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Affiliation(s)
- Maximilian Schilling
- Institut für Genetik, Rheinische Friedrich-Wilhelms Universität Bonn, 53115 Bonn, Germany
| | - Archana B Prusty
- Theodor Boveri Institute, Biocenter of the University of Würzburg, 97074 Würzburg, Germany
| | - Björn Boysen
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | | | - Yannick L Riedel
- Institut für Genetik, Rheinische Friedrich-Wilhelms Universität Bonn, 53115 Bonn, Germany
| | - Alma Husedzinovic
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Homa Rasouli
- Evotec SE, Am Klopferspitz 19a, 82152 Martinsried, Germany
| | - Angelika König
- Institut für Genetik, Rheinische Friedrich-Wilhelms Universität Bonn, 53115 Bonn, Germany
| | - Pradhipa Ramanathan
- Theodor Boveri Institute, Biocenter of the University of Würzburg, 97074 Würzburg, Germany
| | - Jürgen Reymann
- Advanced Biological Screening Facility, BioQuant Centre, Universität Heidelberg, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany
| | - Holger Erfle
- Advanced Biological Screening Facility, BioQuant Centre, Universität Heidelberg, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany
| | - Henrik Daub
- Evotec SE, Am Klopferspitz 19a, 82152 Martinsried, Germany
| | - Utz Fischer
- Theodor Boveri Institute, Biocenter of the University of Würzburg, 97074 Würzburg, Germany
| | - Oliver J Gruss
- Institut für Genetik, Rheinische Friedrich-Wilhelms Universität Bonn, 53115 Bonn, Germany; Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
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17
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Davidian A, Koshel E, Dyomin A, Galkina S, Saifitdinova A, Gaginskaya E. On some structural and evolutionary aspects of rDNA amplification in oogenesis of Trachemys scripta turtles. Cell Tissue Res 2020; 383:853-864. [PMID: 32897424 DOI: 10.1007/s00441-020-03282-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 08/12/2020] [Indexed: 10/23/2022]
Abstract
The features of rDNA amplification have been studied in oocytes of the red-eared slider Trachemys scripta using a number of specific histochemical and cytomolecular methods. A single nucleolus in early diplotene oocytes is associated with the nucleolus organizer region (NOR). With oocyte growth, the number of nucleoli increases dramatically and reaches hundreds by the lampbrush chromosome stage (pre-vitellogenesis). RNA-polymerase I, fibrillarin, and PCNA immunodetection in the amplified nucleoli and FISH of the 5'ETS probe to the oocyte nuclear content suggest pre-rRNA and rDNA synthesis in the nucleoli at all stages studied. This implies a continuous reproduction of the nucleoli during oocyte development from early diplotene up to vitellogenesis. The data obtained offer a different way for rDNA amplification and formation of extrachromosomal nucleoli in turtle oocytes compared with the amplified nucleoli formation in amphibian and fish oocytes. In the Sauropsida clade of Archelosauria, which includes turtles, crocodiles, and birds, rDNA function is known to be suppressed in avian oogenesis during the lampbrush stage (Gaginskaya et al. in Cytogenet Genome Res 124:251-267, 2009).
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Affiliation(s)
- Asya Davidian
- St Petersburg University, St Petersburg, 199034, Russia
| | | | - Alexander Dyomin
- St Petersburg University, St Petersburg, 199034, Russia.,Saratov State Medical University, Saratov, 410000, Russia
| | | | - Alsu Saifitdinova
- Herzen State Pedagogical University of Russia, St Petersburg, 191186, Russia
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18
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Calise SJ, Chan EKL. Anti-rods/rings autoantibody and IMPDH filaments: an update after fifteen years of discovery. Autoimmun Rev 2020; 19:102643. [PMID: 32805424 DOI: 10.1016/j.autrev.2020.102643] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 03/27/2020] [Indexed: 02/07/2023]
Abstract
Autoantibodies to unknown subcellular rod and ring-shaped structures were first discovered in sera from hepatitis C patients in 2005. Early studies showed a strong association between these anti-rods/rings antibodies (anti-RR) and the standard of care interferon-α plus ribavirin combination therapy (IFN/RBV), suggesting that anti-RR are drug-induced autoantibodies. In the context of hepatitis C, anti-RR have been linked with relapse from or lack of response to IFN/RBV in some patient cohorts. However, examples of anti-RR in other diseases and healthy individuals have also been reported over the years, although anti-RR remains a rare autoantibody response in general. The advent of new direct-acting antiviral drugs for chronic hepatitis C and studies of anti-RR from different parts of the world are also beginning to change the perception of anti-RR. The nucleotide biosynthetic enzyme inosine monophosphate dehydrogenase (IMPDH) has been identified as the major autoantigen recognized by anti-RR. Coincidentally, the assembly of IMPDH into micron-scale rod and ring-shaped structures was discovered around the same time as anti-RR. Knowledge of the fundamental biological properties and cellular functions of these structures, referred to as "IMPDH filaments" by cell biologists, has advanced in parallel to anti-RR antibodies. Recent studies have revealed that IMPDH filament assembly is a mechanism to prevent feedback inhibition of IMPDH and is therefore important for the increased nucleotide production required in hyperproliferating cells, like activated T cells. Fifteen years later, we review the history and current knowledge in both the anti-RR autoantibody and IMPDH filament fields. TAKE-HOME MESSAGE: Anti-rods/rings are recognized as an example of a drug-induced autoantibody in hepatitis C patients treated with interferon and ribavirin, although new studies suggest anti-rods/rings may be detected in other contexts and may depend on unknown environmental or genetic factors in different populations. Recent data suggest that the assembly of IMPDH into rod and ring structures, the targets of anti-rods/rings autoantibody, is a mechanism for hyperproliferating cells, like activated T cells, to maintain increased guanine nucleotide levels to support rapid cell division.
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Affiliation(s)
- S John Calise
- Department of Oral Biology, University of Florida, 1395 Center Drive, Gainesville, FL 32610-0424, USA.
| | - Edward K L Chan
- Department of Oral Biology, University of Florida, 1395 Center Drive, Gainesville, FL 32610-0424, USA.
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19
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Hu YH, Wang Y, Wang F, Dong YM, Jiang WL, Wang YP, Zhong X, Ma LX. SPOP negatively regulates Toll-like receptor-induced inflammation by disrupting MyD88 self-association. Cell Mol Immunol 2020; 18:1708-1717. [PMID: 32235916 PMCID: PMC8245473 DOI: 10.1038/s41423-020-0411-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 03/07/2020] [Indexed: 11/10/2022] Open
Abstract
Toll-like receptor (TLR) signaling pathways need to be tightly controlled to avoid excessive inflammation and unwanted damage to the host. Myeloid differentiation primary response gene 88 (MyD88) is a critical adaptor of TLR signaling. Here, we identified the speckle-type POZ protein (SPOP) as a MyD88-associated protein. SPOP was recruited to MyD88 following TLR4 activation. TLR4 activation also caused the translocation of SPOP from the nucleus to the cytoplasm. SPOP depletion promoted the aggregation of MyD88 and recruitment of the downstream signaling kinases IRAK4, IRAK1 and IRAK2. Consistently, overexpression of SPOP inhibited the TLR4-mediated activation of NF-κB and production of inflammatory cytokines, whereas SPOP depletion had the opposite effects. Furthermore, knockdown of SPOP increased MyD88 aggregation and inflammatory cytokine production upon TLR2, TLR7 and TLR9 activation. Our findings reveal a mechanism by which MyD88 is regulated and highlight a role for SPOP in limiting inflammatory responses.
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Affiliation(s)
- Yun-Hong Hu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Yang Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Fei Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Yan-Ming Dong
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Wan-Ling Jiang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Ya-Ping Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Xing Zhong
- School of Biological and Chemical Engineering, College of Zhixing, Hubei University, Wuhan, 430011, China
| | - Li-Xin Ma
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China.
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20
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Krasikova A, Kulikova T. Identification of Genomic Loci Responsible for the Formation of Nuclear Domains Using Lampbrush Chromosomes. Noncoding RNA 2019; 6:ncrna6010001. [PMID: 31881720 PMCID: PMC7151628 DOI: 10.3390/ncrna6010001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 12/19/2019] [Accepted: 12/22/2019] [Indexed: 12/12/2022] Open
Abstract
In the cell nuclei, various types of nuclear domains assemble as a result of transcriptional activity at specific chromosomal loci. Giant transcriptionally active lampbrush chromosomes, which form in oocyte nuclei of amphibians and birds enable the mapping of genomic sequences with high resolution and the visualization of individual transcription units. This makes avian and amphibian oocyte nuclei an advantageous model for studying locus-specific nuclear domains. We developed two strategies for identification and comprehensive analysis of the genomic loci involved in nuclear domain formation on lampbrush chromosomes. The first approach was based on the sequential FISH-mapping of BAC clones containing genomic DNA fragments with a known chromosomal position close to the locus of a nuclear domain. The second approach involved mechanical microdissection of the chromosomal region adjacent to the nuclear domain followed by the generation of FISH-probes and DNA sequencing. Furthermore, deciphering the DNA sequences from the dissected material by high throughput sequencing technologies and their mapping to the reference genome helps to identify the genomic region responsible for the formation of the nuclear domain. For those nuclear domains structured by nascent transcripts, identification of genomic loci of their formation is a crucial step in the identification of scaffold RNAs.
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21
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Cruvinel WDM, Andrade LEC, von Mühlen CA, Dellavance A, Ximenes AC, Bichara CD, Bueno C, Mangueira CLP, Bonfá E, de Almeida Brito F, Flumian FB, da Silva GG, Rêgo J, Dos Anjos LME, Slhessarenko N, Pasoto SG, Neves SPF, Valim V, Dos Santos WS, Francescantonio PLC. V Brazilian consensus guidelines for detection of anti-cell autoantibodies on hep-2 cells. Adv Rheumatol 2019; 59:28. [PMID: 31269997 DOI: 10.1186/s42358-019-0069-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 06/20/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The V Brazilian Consensus for determination of autoantibodies against cellular constituents on HEp-2 cells, held in Brasilia (DF, Brazil) on August 27, 2016, discussed the harmonization between the Brazilian Consensus on ANA (BCA) guidelines and the International Consensus on ANA Patterns (ICAP) recommendations ( www.anapatterns.org ). Initial guidelines were formulated by the group of Brazilian experts with the purpose of guiding and enabling Brazilian clinical laboratories to adopt recommendations and to provide a common standard for national and international consensuses. MAINBODY Twenty Brazilian researchers and experts from universities and clinical laboratories representing the various geographical regions of the country participated in the meeting. Three main topics were discussed, namely the harmonization between the BCA guidelines and latest recommendations of the ICAP initiative, the adjustment of the terminology and report on HEp-2 patterns, and a reassessment of quality assurance parameters. For the three topics, our aim was to establish specific guidelines. All recommendations were based on consensus among participants. There was concrete progress in the adjustment of the BCA guidelines to match the ICAP guidelines. To a certain extent, this derives from the fact that ICAP recommendations were largely based on the algorithm and recommendations of the IV Brazilian ANA Consensus, as consistently recognized in the ICAP publications and presentations. However, although there is great overlap between the two Consensuses, there are some point divergences. These specific items were individually and extensively discussed, and it was acknowledged that in several points ICAP improved recommendations previously issued by the Brazilian ANA Consensus and these changes were readily implemented. Regarding some specific topics, the BCA panel of experts felt that the previously issued recommendations remained relevant and possibly will require further discussion with ICAP. The term anti-cell antibodies was adopted as the recommended designation, recognizing that the assay addresses antibodies against antigens in the nucleus and in other cell compartments. However, the acronym ANA HEp-2 was maintained due to historical and regulatory reasons. It was also signalized that the latest trend in ICAP is to adopt the term Indirect Immunofluorescent Assay on HEp-2 cell substrate (HEp-2 IIFA). In addition, the quality assurance strategies previously presented were ratified and emphasized. CONCLUSION The V BCA edition was successful in establishing an overall harmonization with the ICAP recommendations for interpretation of the HEp-2 IIFA test, pinpointing the perspectives in filling the remaining gaps between both initiatives.
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Affiliation(s)
- Wilson de Melo Cruvinel
- Pontifícia Universidade Católica de Goiás (PUC Goiás), Escola de Ciências Médicas, Farmacêuticas e Biomédicas, Avenida Universitária 1.440, Setor Universitário, Goiânia, GO, CEP, 74605-010, Brazil.
| | - Luis Eduardo Coelho Andrade
- Disciplina de Reumatologia, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), Divisão de Imunologia, Fleury Medicina e Saúde, São Paulo, SP, Brazil
| | | | - Alessandra Dellavance
- Divisão de Pesquisa, Inovação e Desenvolvimento, Fleury Medicina e Saúde, São Paulo, SP, Brazil
| | | | - Carlos David Bichara
- Faculdade de Medicina Famaz, Amaral Costa Medicina Diagnóstica, Belém, PA, Brazil
| | - Cleonice Bueno
- Laboratórios de Investigação Médica, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (FM-USP), São Paulo, SP, Brazil
| | | | - Eloísa Bonfá
- Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
| | | | | | | | - Jozelia Rêgo
- Faculdade de Medicina, Universidade Federal de Goiás (UFG), Goiânia, GO, Brazil
| | | | - Natasha Slhessarenko
- Universidade Federal de Mato Grosso (UFMT) e Grupo DASA Cuiabá, Cuiabá, MT, Brazil
| | - Sandra Gofinet Pasoto
- Serviço de Reumatologia e Laboratório de Autoimunidade da Divisão de Laboratório Central do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Suzane Pretti Figueiredo Neves
- Departamento de Propedêutica Complementar da Faculdade de Medicina, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Valéria Valim
- Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil
| | - Wilton Silva Dos Santos
- Escola Superior de Ciências da Saúde do Distrito Federal e Laboratório Sabin, Brasília, DF, Brazil
| | - Paulo Luiz Carvalho Francescantonio
- Pontifícia Universidade Católica de Goiás (PUC Goiás), Escola de Ciências Médicas, Farmacêuticas e Biomédicas, Avenida Universitária 1.440, Setor Universitário, Goiânia, GO, CEP, 74605-010, Brazil.
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Damoiseaux J, Andrade LEC, Carballo OG, Conrad K, Francescantonio PLC, Fritzler MJ, Garcia de la Torre I, Herold M, Klotz W, Cruvinel WDM, Mimori T, von Muhlen C, Satoh M, Chan EK. Clinical relevance of HEp-2 indirect immunofluorescent patterns: the International Consensus on ANA patterns (ICAP) perspective. Ann Rheum Dis 2019; 78:879-889. [PMID: 30862649 PMCID: PMC6585284 DOI: 10.1136/annrheumdis-2018-214436] [Citation(s) in RCA: 184] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 01/23/2019] [Indexed: 12/21/2022]
Abstract
The indirect immunofluorescence assay (IIFA) on HEp-2 cells is widely used for detection of antinuclear antibodies (ANA). The dichotomous outcome, negative or positive, is integrated in diagnostic and classification criteria for several systemic autoimmune diseases. However, the HEp-2 IIFA test has much more to offer: besides the titre or fluorescence intensity, it also provides fluorescence pattern(s). The latter include the nucleus and the cytoplasm of interphase cells as well as patterns associated with mitotic cells. The International Consensus on ANA Patterns (ICAP) initiative has previously reached consensus on the nomenclature and definitions of HEp-2 IIFA patterns. In the current paper, the ICAP consensus is presented on the clinical relevance of the 29 distinct HEp-2 IIFA patterns. This clinical relevance is primarily defined within the context of the suspected disease and includes recommendations for follow-up testing. The discussion includes how this information may benefit the clinicians in daily practice and how the knowledge can be used to further improve diagnostic and classification criteria.
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Affiliation(s)
- Jan Damoiseaux
- Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | | | - Orlando Gabriel Carballo
- Department of Immunology, Instituto Universitario del Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.,Laboratory of Immunology, Hospital General de Agudos Carlos G Durand, Buenos Aires, Argentina
| | - Karsten Conrad
- Immunology, Medical Faculty TU Dresden, Dresden, Germany
| | | | | | | | - Manfred Herold
- Rheumatology Unit, Clinical Department of General Internal Medicine, Innsbruck Medical University, Innsbruck, Austria
| | - Werner Klotz
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Tsuneyo Mimori
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate school of Medicine, Kyoto, Japan
| | | | - Minoru Satoh
- Department of Clinical Nursing, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Edward K Chan
- Department of Oral Biology, University of Florida, Gainesville, Florida, USA
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23
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Andrade LE, Klotz W, Herold M, Conrad K, Rönnelid J, Fritzler MJ, von Mühlen CA, Satoh M, Damoiseaux J, de Melo Cruvinel W, Chan EK. International consensus on antinuclear antibody patterns: definition of the AC-29 pattern associated with antibodies to DNA topoisomerase I. ACTA ACUST UNITED AC 2018; 56:1783-1788. [DOI: 10.1515/cclm-2018-0188] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 04/25/2018] [Indexed: 11/15/2022]
Abstract
Abstract
The indirect immunofluorescence assay (IFA) on HEp-2 cells is the reference method for autoantibody screening. The HEp-2 IFA pattern provides useful information on the possible autoantibodies in the sample. The International Consensus on Antinuclear Antibody Patterns (ICAP) initiative seeks to define and harmonize the nomenclature of HEp-2 IFA patterns. The most relevant and usual patterns have been assigned an alphanumeric code from anti-cell (AC)-1 to AC-28 and were organized into a classification algorithm (www.ANApatterns.org). The systemic sclerosis-associated autoantibodies to DNA topoisomerase I (Topo I) produce a peculiar composite 5-element HEp-2 IFA pattern (Topo I-like pattern) comprising the staining of the nucleus, metaphase chromatin plate, nucleolar organizing region, cytoplasm and nucleolus. In a recent assessment of the European Consensus Finding Study Group on autoantibodies, a well-defined anti-Topo I sample was blindly analyzed and classified according to ICAP AC patterns by 43 participant laboratories across Europe. There were wide variations among these laboratories in reporting nuclear, nucleolar and cytoplasmic patterns, indicating the inadequacy of the existing AC patterns to report the Topo I-like pattern. Several ICAP member laboratories independently demonstrated the overall consistency of the HEp-2 IFA Topo I-like pattern using HEp-2 slides from different manufacturers. The ICAP committee reviewed 24 candidate images and selected the four most representative images to be available on the ICAP website. The proper recognition of the AC-29 pattern should trigger suspicion of the presence of anti-Topo I antibodies, which may engender appropriate analyte-specific reflex tests to confirm the autoantibody specificity.
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Affiliation(s)
- Luis E.C. Andrade
- Department of Medicine, Rheumatology Division, Escola Paulista de Medicina, Federal University of São Paulo , Rua Botucatu 740 , São Paulo, SP 04023-062 , Brazil
- Immunology Division, Fleury Medicine and Health Laboratories , São Paulo , Brazil , Phone/Fax: +55-11-5576-4239
| | - Werner Klotz
- Department of Internal Medicine II , Medical University of Innsbruck , Innsbruck , Austria
| | - Manfred Herold
- Department of Internal Medicine II , Medical University of Innsbruck , Innsbruck , Austria
| | - Karsten Conrad
- Institute of Immunology , Technical University of Dresden , Dresden , Germany
| | - Johan Rönnelid
- Department of Immunology, Genetics and Pathology , Uppsala University , Uppsala , Sweden
| | - Marvin J. Fritzler
- Department of Medicine, Cumming School of Medicine , University of Calgary , Calgary, AB , Canada
| | | | - Minoru Satoh
- Department of Clinical Nursing , University of Occupational and Environmental Health , Kitakyushu , Japan
| | - Jan Damoiseaux
- Central Diagnostic Laboratory , Maastricht University, Medical Center , Maastricht , The Netherlands
| | | | - Edward K.L. Chan
- Department of Oral Biology , University of Florida , Gainesville, FL , USA
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24
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Kobayashi M, Chandrasekhar A, Cheng C, Martinez JA, Ng H, de la Hoz C, Zochodne DW. Diabetic polyneuropathy, sensory neurons, nuclear structure and spliceosome alterations: a role for CWC22. Dis Model Mech 2017; 10:215-224. [PMID: 28250049 PMCID: PMC5374325 DOI: 10.1242/dmm.028225] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 12/23/2016] [Indexed: 12/31/2022] Open
Abstract
Unique deficits in the function of adult sensory neurons as part of their early neurodegeneration might account for progressive polyneuropathy during chronic diabetes mellitus. Here, we provide structural and functional evidence for aberrant pre-mRNA splicing in a chronic type 1 model of experimental diabetic polyneuropathy (DPN). Cajal bodies (CBs), unique nuclear substructures involved in RNA splicing, increased in number in diabetic sensory neurons, but their expected colocalization with survival motor neuron (SMN) proteins was reduced - a mislocalization described in motor neurons of spinal muscular atrophy. Small nuclear ribonucleoprotein particles (snRNPs), also participants in the spliceosome, had abnormal multiple nuclear foci unassociated with CBs, and their associated snRNAs were reduced. CWC22, a key spliceosome protein, was aberrantly upregulated in diabetic dorsal root ganglia (DRG), and impaired neuronal function. CWC22 attenuated sensory neuron plasticity, with knockdown in vitro enhancing their neurite outgrowth. Further, axonal delivery of CWC22 siRNA unilaterally to locally knock down the aberrant protein in diabetic nerves improved aspects of sensory function in diabetic mice. Collectively, our findings identify subtle but significant alterations in spliceosome structure and function, including dysregulated CBs and CWC22 overexpression, in diabetic sensory neurons that offer new ideas regarding diabetic sensory neurodegeneration in polyneuropathy.
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Affiliation(s)
- Masaki Kobayashi
- Division of Neurology and Department of Medicine, Faculty of Medicine and Dentistry, and the Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada, T6G 2G3
| | - Ambika Chandrasekhar
- Division of Neurology and Department of Medicine, Faculty of Medicine and Dentistry, and the Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada, T6G 2G3
| | - Chu Cheng
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Faculty of Medicine, University of Calgary, Canada, T2N 4N1
| | - Jose A Martinez
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Faculty of Medicine, University of Calgary, Canada, T2N 4N1
| | - Hilarie Ng
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Faculty of Medicine, University of Calgary, Canada, T2N 4N1
| | - Cristiane de la Hoz
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Faculty of Medicine, University of Calgary, Canada, T2N 4N1
| | - Douglas W Zochodne
- Division of Neurology and Department of Medicine, Faculty of Medicine and Dentistry, and the Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada, T6G 2G3 .,Hotchkiss Brain Institute and Department of Clinical Neurosciences, Faculty of Medicine, University of Calgary, Canada, T2N 4N1
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25
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Au EYL. ANA Testing: What should we know about the methods, indication and interpretation? HONG KONG BULLETIN ON RHEUMATIC DISEASES 2017. [DOI: 10.1515/hkbrd-2017-0007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Though ANA is a common test requested in several settings, one may not be aware of the potential traps for interpretation. Nowadays, there is a trend for autoantibodies diagnostics to move from traditional time honored manual methods to high throughput automated platforms. Nevertheless, the clinical significance and assay performance characteristics may be different from those “historical” methods. Though indirect immunofluorescence is the gold standard method for ANA tests, different laboratories vary in the slides (from different cell lines and commercial source, e.g., Hep 2, Hep 2000, etc.), screening dilutions, terminology, reporting format and expertise. Hence, discrepancy in results among different laboratories is not uncommon and could be confusing. Knowing the assay characteristic and limitations helps proper results interpretation and facilitate patient’s management. Indeed, the titer and pattern by indirect immunofluorescence do provide valuable information in screening patients. In particular, DFS pattern with the associated anti-DFS70 antibodies has been shown to have a role to risk stratify cases referred for suspected autoimmune rheumatic disease.
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26
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Chen Z, Gui B, Zhang Y, Xie G, Li W, Liu S, Xu B, Wu C, He L, Yang J, Yi X, Yang X, Sun L, Liang J, Shang Y. Identification of a 35S U4/U6.U5 tri-small nuclear ribonucleoprotein (tri-snRNP) complex intermediate in spliceosome assembly. J Biol Chem 2017; 292:18113-18128. [PMID: 28878014 DOI: 10.1074/jbc.m117.797357] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 08/28/2017] [Indexed: 11/06/2022] Open
Abstract
The de novo assembly and post-splicing reassembly of the U4/U6.U5 tri-snRNP remain to be investigated. We report here that ZIP, a protein containing a CCCH-type zinc finger and a G-patch domain, as characterized by us previously, regulates pre-mRNA splicing independent of RNA binding. We found that ZIP physically associates with the U4/U6.U5 tri-small nuclear ribonucleoprotein (tri-snRNP). Remarkably, the ZIP-containing tri-snRNP, which has a sedimentation coefficient of ∼35S, is a tri-snRNP that has not been described previously. We also found that the 35S tri-snRNP contains hPrp24, indicative of a state in which the U4/U6 di-snRNP is integrating with the U5 snRNP. We found that the 35S tri-snRNP is enriched in the Cajal body, indicating that it is an assembly intermediate during 25S tri-snRNP maturation. We showed that the 35S tri-snRNP also contains hPrp43, in which ATPase/RNA helicase activities are stimulated by ZIP. Our study identified, for the first time, a tri-snRNP intermediate, shedding new light on the de novo assembly and recycling of the U4/U6.U5 tri-snRNP.
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Affiliation(s)
- Zhe Chen
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Bin Gui
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yu Zhang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Guojia Xie
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Wanjin Li
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Shumeng Liu
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Bosen Xu
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Chongyang Wu
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Lin He
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jianguo Yang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Xia Yi
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Xiaohan Yang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Luyang Sun
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jing Liang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yongfeng Shang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China, .,the Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China, and.,the Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
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27
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Love AJ, Yu C, Petukhova NV, Kalinina NO, Chen J, Taliansky ME. Cajal bodies and their role in plant stress and disease responses. RNA Biol 2017; 14:779-790. [PMID: 27726481 PMCID: PMC5519230 DOI: 10.1080/15476286.2016.1243650] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/19/2016] [Accepted: 09/27/2016] [Indexed: 12/11/2022] Open
Abstract
Cajal bodies (CBs) are distinct sub-nuclear structures that are present in eukaryotic living cells and are often associated with the nucleolus. CBs play important roles in RNA metabolism and formation of RNPs involved in transcription, splicing, ribosome biogenesis, and telomere maintenance. Besides these primary roles, CBs appear to be involved in additional functions that may not be directly related to RNA metabolism and RNP biogenesis. In this review, we assess possible roles of plant CBs in RNA regulatory pathways such as nonsense-mediated mRNA decay and RNA silencing. We also summarize recent progress and discuss new non-canonical functions of plant CBs in responses to stress and disease. It is hypothesized that CBs can regulate these responses via their interaction with poly(ADP ribose)polymerase (PARP), which is known to play an important role in various physiological processes including responses to biotic and abiotic stresses. It is suggested that CBs and their components modify PARP activities and functions.
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Affiliation(s)
- Andrew J. Love
- Cell and Molecular Sciences, James Hutton Institute, Invergowrie, Dundee, UK
| | - Chulang Yu
- State Key Laboratory Breeding Base for Sustainable Pest and Disease Control, Key Laboratory of Biotechnology in Plant Protection of MOA and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | | | - Natalia O. Kalinina
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, Russia
| | - Jianping Chen
- State Key Laboratory Breeding Base for Sustainable Pest and Disease Control, Key Laboratory of Biotechnology in Plant Protection of MOA and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Michael E. Taliansky
- Cell and Molecular Sciences, James Hutton Institute, Invergowrie, Dundee, UK
- State Key Laboratory Breeding Base for Sustainable Pest and Disease Control, Key Laboratory of Biotechnology in Plant Protection of MOA and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
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28
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Neural Differentiation in HDAC1-Depleted Cells Is Accompanied by Coilin Downregulation and the Accumulation of Cajal Bodies in Nucleoli. Stem Cells Int 2017; 2017:1021240. [PMID: 28337219 PMCID: PMC5350323 DOI: 10.1155/2017/1021240] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 01/12/2017] [Accepted: 01/26/2017] [Indexed: 12/23/2022] Open
Abstract
Cajal bodies (CBs) are important compartments containing accumulated proteins that preferentially regulate RNA-related nuclear events, including splicing. Here, we studied the nuclear distribution pattern of CBs in neurogenesis. In adult brains, coilin was present at a high density, but CB formation was absent in the nuclei of the choroid plexus of the lateral ventricles. Cells of the adult hippocampus were characterized by a crescent-like morphology of coilin protein. We additionally observed a 70 kDa splice variant of coilin in adult mouse brains, which was different to embryonic brains and mouse pluripotent embryonic stem cells (mESCs), characterized by the 80 kDa standard variant of coilin. Here, we also showed that depletion of coilin is induced during neural differentiation and HDAC1 deficiency in mESCs caused coilin accumulation inside the fibrillarin-positive region of the nucleoli. A similar distribution pattern was observed in adult brain hippocampi, characterized by lower levels of both coilin and HDAC1. In summary, we observed that neural differentiation and HDAC1 deficiency lead to coilin depletion and coilin accumulation in body-like structures inside the nucleoli.
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29
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Kulikova T, Khodyuchenko T, Petrov Y, Krasikova A. Low-voltage scanning electron microscopy study of lampbrush chromosomes and nuclear bodies in avian and amphibian oocytes. Sci Rep 2016; 6:36878. [PMID: 27857188 PMCID: PMC5114574 DOI: 10.1038/srep36878] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 10/24/2016] [Indexed: 12/01/2022] Open
Abstract
Nucleus is a highly compartmentalized part of the cell where the key processes of genome functionality are realized through the formation of non-membranous nuclear domains. Physically nuclear domains appear as liquid droplets with different viscosity stably maintained throughout the interphase or during the long diplotene stage of meiosis. Since nuclear body surface represents boundary between two liquid phases, the ultrastructural surface topography of nuclear domains is of an outstanding interest. The aim of this study was to examine ultrathin surface topography of the amphibian and avian oocyte nuclear structures such as lampbrush chromosomes, nucleoli, histone-locus bodies, Cajal body-like bodies, and the interchromatin granule clusters via low-voltage scanning electron microscopy. Our results demonstrate that nuclear bodies with similar molecular composition may differ dramatically in the surface topography and vice versa, nuclear bodies that do not share common molecular components may possess similar topographical characteristics. We also have analyzed surface distribution of particular nuclear antigens (double stranded DNA, coilin and splicing snRNA) using indirect immunogold labeling with subsequent secondary electron detection of gold nanoparticles. We suggest that ultrastructural surface morphology reflects functional status of a nuclear body.
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Affiliation(s)
| | | | - Yuri Petrov
- Saint-Petersburg State University, Saint-Petersburg, Russia
| | - Alla Krasikova
- Saint-Petersburg State University, Saint-Petersburg, Russia
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30
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Abstract
Aside from nucleoli, Cajal bodies (CBs) are the best-characterized organelles of mammalian cell nuclei. Like nucleoli, CBs concentrate ribonucleoproteins (RNPs), in particular, spliceosomal small nuclear RNPs (snRNPs) and small nucleolar RNPs (snoRNPs). In one of the best-defined functions of CBs, most of the snoRNPs are involved in site-specific modification of snRNAs. The two major modifications are pseudouridylation and 2'-O-methylation that are guided by the box H/ACA and C/D snoRNPs, respectively. This review details the modifications, their function, the mechanism of modification, and the machineries involved. We dissect the different classes of noncoding RNAs that meet in CBs, guides and substrates. Open questions and conundrums, often raised and appearing due to experimental limitations, are pointed out and discussed. The emphasis of the review is on mammalian CBs and their function in modification of noncoding RNAs.
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Affiliation(s)
- U Thomas Meier
- a Albert Einstein College of Medicine , Department of Anatomy and Structural Biology , Bronx , NY , USA
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31
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Hebert MD, Poole AR. Towards an understanding of regulating Cajal body activity by protein modification. RNA Biol 2016; 14:761-778. [PMID: 27819531 DOI: 10.1080/15476286.2016.1243649] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The biogenesis of small nuclear ribonucleoproteins (snRNPs), small Cajal body-specific RNPs (scaRNPs), small nucleolar RNPs (snoRNPs) and the telomerase RNP involves Cajal bodies (CBs). Although many components enriched in the CB contain post-translational modifications (PTMs), little is known about how these modifications impact individual protein function within the CB and, in concert with other modified factors, collectively regulate CB activity. Since all components of the CB also reside in other cellular locations, it is also important that we understand how PTMs affect the subcellular localization of CB components. In this review, we explore the current knowledge of PTMs on the activity of proteins known to enrich in CBs in an effort to highlight current progress as well as illuminate paths for future investigation.
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Affiliation(s)
- Michael D Hebert
- a Department of Biochemistry , The University of Mississippi Medical Center , Jackson , MS , USA
| | - Aaron R Poole
- a Department of Biochemistry , The University of Mississippi Medical Center , Jackson , MS , USA
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32
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Trinkle-Mulcahy L, Sleeman JE. The Cajal body and the nucleolus: "In a relationship" or "It's complicated"? RNA Biol 2016; 14:739-751. [PMID: 27661468 DOI: 10.1080/15476286.2016.1236169] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
From their initial identification as 'nucleolar accessory bodies' more than a century ago, the relationship between Cajal bodies and nucleoli has been a subject of interest and controversy. In this review, we seek to place recent developments in the understanding of the physical and functional relationships between the 2 structures in the context of historical observations. Biophysical models of nuclear body formation, the molecular nature of CB/nucleolus interactions and the increasing list of joint roles for CBs and nucleoli, predominantly in assembling ribonucleoprotein (RNP) complexes, are discussed.
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Affiliation(s)
- Laura Trinkle-Mulcahy
- a Department of Cellular and Molecular Medicine , Ottawa Institute of Systems Biology, University of Ottawa , Ottawa , ON , Canada
| | - Judith E Sleeman
- b BSRC Complex, School of Biology, University of St Andrews , UK
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33
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Abstract
Cajal is commonly regarded as the father of modern neuroscience in recognition of his fundamental work on the structure of the nervous system. But Cajal also made seminal contributions to the knowledge of nuclear structure in the early 1900s, including the discovery of the "accessory body" later renamed "Cajal body" (CB). This important nuclear structure has emerged as a center for the assembly of ribonucleoproteins (RNPs) required for splicing, ribosome biogenesis and telomere maintenance. The modern era of CB research started in the 1990s with the discovery of coilin, now known as a scaffold protein of CBs, and specific probes for small nuclear RNAs (snRNAs). In this review, we summarize what we have learned in the recent decades concerning CBs in post-mitotic neurons, thereby ruling out dynamic changes in CB functions during the cell cycle. We show that CBs are particularly prominent in neurons, where they frequently associate with the nucleolus. Neuronal CBs are transcription-dependent nuclear organelles. Indeed, their number dynamically accommodates to support the high neuronal demand for splicing and ribosome biogenesis required for sustaining metabolic and bioelectrical activity. Mature neurons have canonical CBs enriched in coilin, survival motor neuron protein and snRNPs. Disruption and loss of neuronal CBs associate with severe neuronal dysfunctions in several neurological disorders such as motor neuron diseases. In particular, CB depletion in motor neurons seems to reflect a perturbation of transcription and splicing in spinal muscular atrophy, the most common genetic cause of infant mortality.
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Affiliation(s)
- Miguel Lafarga
- a Departamento de Anatomía y Biología Celular and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)" , Universidad de Cantabria-IDIVAL , Santander , Spain
| | - Olga Tapia
- a Departamento de Anatomía y Biología Celular and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)" , Universidad de Cantabria-IDIVAL , Santander , Spain
| | - Ana M Romero
- a Departamento de Anatomía y Biología Celular and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)" , Universidad de Cantabria-IDIVAL , Santander , Spain
| | - Maria T Berciano
- a Departamento de Anatomía y Biología Celular and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)" , Universidad de Cantabria-IDIVAL , Santander , Spain
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34
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Fritzler MJ, Chan EKL. Dr Eng M. Tan: a tribute to an enduring legacy in autoimmunity. Lupus 2016; 26:208-217. [PMID: 27539991 DOI: 10.1177/0961203316664598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
At the age of ninety years, Dr Eng Meng Tan has had a remarkable impact on the accumulated knowledge of autoimmune diseases, including seminal findings in systemic lupus erythematosus (SLE) and a wide range of other autoimmune diseases. Dating to the first description of the Sm (Smith) autoantibody in SLE, his focus has been the use of autoantibodies as probes to identify and elucidate novel cellular molecules and then translating these discoveries into biomarkers and immunoassays for a wide range of these diseases and, later, cancer. He led efforts to standardize autoantibody nomenclature and testing protocols. Through his mentorship a great number of trainees and collaborators have had remarkably successful careers, and by that virtue he has garnered a remarkable continuing legacy.
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Affiliation(s)
- M J Fritzler
- 1 University of Calgary, Cumming School of Medicine, Calgary, Canada
| | - E K L Chan
- 2 Department of Oral Biology, University of Florida, Gainesville, USA
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Uomori K, Nozawa K, Ikeda K, Doe K, Yamada Y, Yamaguchi A, Fujishiro M, Kawasaki M, Morimoto S, Takamori K, Sekigawa I, Chan EKL, Takasaki Y. A re-evaluation of anti-NA-14 antibodies in patients with primary Sjögren's syndrome: Significant role of interferon-γ in the production of autoantibodies against NA-14. Autoimmunity 2016; 49:347-56. [PMID: 27328271 DOI: 10.1080/08916934.2016.1196676] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Novel autoantibodies against nuclear antigen of 14 kDa (NA-14)/Sjögren's syndrome nuclear antigen-1 (SSNA-1) are predominantly recognized in sera of patients with primary Sjögren's syndrome (pSS). However, the detailed characteristics of the anti-NA-14 antibody remain unknown. Here, we sought to clarify the characteristics of anti-SSNA-1/NA-14 antibodies and the mechanisms of autoantibody production using sera from patients with connective tissue diseases (including pSS), autoimmune sera reacting with standard autoantigens (SS-A/Ro and/or SS-B/La, ds DNA, Scl-70 and Jo-1), and normal healthy controls (NHCs). Anti-NA-14 antibodies were predominantly recognized in sera from patients with pSS and in autoimmune sera reacting with thSS-A/Ro and/or -SS-B/Lo. Indirect immunofluorescence analysis showed that NA-14 was strongly expressed in mitotic-phase cells. Patients with pSS having anti-NA-14 antibodies exhibited significant elevation of serum IP-10 and BAFF compared to that in patients with pSS without anti-NA-14 antibodies and NHCs. Thus, our data demonstrated that anti-NA-14 antibodies could be classified as novel autoantibodies reacting with mitosis-related autoantigens predominantly recognized in pSS. Moreover, interferon-γ played an important role in the production of anti-NA-14 autoantibodies as patients with pSS having anti-NA-14 antibodies exhibited increased serum levels of IP-10 and BAFF.
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Affiliation(s)
- Kaori Uomori
- a Department of Internal Medicine and Rheumatology , Faculty of Medicine, Juntendo University , Tokyo , Japan
| | - Kazuhisa Nozawa
- a Department of Internal Medicine and Rheumatology , Faculty of Medicine, Juntendo University , Tokyo , Japan
| | - Keigo Ikeda
- b Juntendo University Urayasu Hospital, Juntendo University Graduate School of Medicine , Urayasu , Japan , and
| | - Kentaro Doe
- a Department of Internal Medicine and Rheumatology , Faculty of Medicine, Juntendo University , Tokyo , Japan
| | - Yusuke Yamada
- a Department of Internal Medicine and Rheumatology , Faculty of Medicine, Juntendo University , Tokyo , Japan
| | - Ayako Yamaguchi
- a Department of Internal Medicine and Rheumatology , Faculty of Medicine, Juntendo University , Tokyo , Japan
| | - Maki Fujishiro
- b Juntendo University Urayasu Hospital, Juntendo University Graduate School of Medicine , Urayasu , Japan , and
| | - Mikiko Kawasaki
- b Juntendo University Urayasu Hospital, Juntendo University Graduate School of Medicine , Urayasu , Japan , and
| | - Shinji Morimoto
- b Juntendo University Urayasu Hospital, Juntendo University Graduate School of Medicine , Urayasu , Japan , and
| | - Kenji Takamori
- b Juntendo University Urayasu Hospital, Juntendo University Graduate School of Medicine , Urayasu , Japan , and
| | - Iwao Sekigawa
- b Juntendo University Urayasu Hospital, Juntendo University Graduate School of Medicine , Urayasu , Japan , and
| | - Edward K L Chan
- c Department of Oral Biology , University of Florida , Gainesville , FL , USA
| | - Yoshinari Takasaki
- a Department of Internal Medicine and Rheumatology , Faculty of Medicine, Juntendo University , Tokyo , Japan
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Identification of Coilin Mutants in a Screen for Enhanced Expression of an Alternatively Spliced GFP Reporter Gene in Arabidopsis thaliana. Genetics 2016; 203:1709-20. [PMID: 27317682 PMCID: PMC4981272 DOI: 10.1534/genetics.116.190751] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/09/2016] [Indexed: 02/02/2023] Open
Abstract
Coilin is a marker protein for subnuclear organelles known as Cajal bodies, which are sites of various RNA metabolic processes including the biogenesis of spliceosomal small nuclear ribonucleoprotein particles. Through self-associations and interactions with other proteins and RNA, coilin provides a structural scaffold for Cajal body formation. However, despite a conspicuous presence in Cajal bodies, most coilin is dispersed in the nucleoplasm and expressed in cell types that lack these organelles. The molecular function of coilin, particularly of the substantial nucleoplasmic fraction, remains uncertain. We identified coilin loss-of-function mutations in a genetic screen for mutants showing either reduced or enhanced expression of an alternatively spliced GFP reporter gene in Arabidopsis thaliana The coilin mutants feature enhanced GFP fluorescence and diminished Cajal bodies compared with wild-type plants. The amount of GFP protein is several-fold higher in the coilin mutants owing to elevated GFP transcript levels and more efficient splicing to produce a translatable GFP mRNA. Genome-wide RNA-sequencing data from two distinct coilin mutants revealed a small, shared subset of differentially expressed genes, many encoding stress-related proteins, and, unexpectedly, a trend toward increased splicing efficiency. These results suggest that coilin attenuates splicing and modulates transcription of a select group of genes. The transcriptional and splicing changes observed in coilin mutants are not accompanied by gross phenotypic abnormalities or dramatically altered stress responses, supporting a role for coilin in fine tuning gene expression. Our GFP reporter gene provides a sensitive monitor of coilin activity that will facilitate further investigations into the functions of this enigmatic protein.
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Abstract
Initially identified as a marker of coiled bodies (now Cajal bodies or CBs), the protein coilin was discovered a quarter of century ago. Coilin is now known to scaffold the CB, but its structure and function are poorly understood. Nearly devoid of predicted structural motifs, coilin has numerous reported molecular interactions that must underlie its role in the formation and function of CBs. In this review, we summarize what we have learned in the past 25 years about coilin's structure, post-transcriptional modifications, and interactions with RNA and proteins. We show that genes with homology to human coilin are found in primitive metazoans and comment on differences among model organisms. Coilin's function in Cajal body formation and RNP metabolism will be discussed in the light of these developments.
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Affiliation(s)
- Martin Machyna
- a Department of Molecular Biophysics & Biochemistry ; Yale University ; New Haven , CT USA
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38
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Chan EKL, Damoiseaux J, Carballo OG, Conrad K, de Melo Cruvinel W, Francescantonio PLC, Fritzler MJ, Garcia-De La Torre I, Herold M, Mimori T, Satoh M, von Mühlen CA, Andrade LEC. Report of the First International Consensus on Standardized Nomenclature of Antinuclear Antibody HEp-2 Cell Patterns 2014-2015. Front Immunol 2015; 6:412. [PMID: 26347739 DOI: 10.3389/fimmu.2015.00412/bibtex] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 07/27/2015] [Indexed: 05/26/2023] Open
Abstract
During the 12th International Workshop on Autoantibodies and Autoimmunity held in Sao Paulo, Brazil, on August 28, 2014, a full day session was devoted to establishing a consensus on the nomenclature of staining patterns observed in the antinuclear antibody (ANA) indirect immunofluorescence test on HEp-2 cells. The current report summarizes the collective agreements with input from the host Brazilian and international communities that represented research, clinical, and diagnostic service laboratories. Patterns are categorized in three major groups (nuclear, cytoplasmic, and mitotic patterns) and each pattern has been defined and described in detail. The consensus nomenclature and representative patterns are made available online at the international consensus on antinuclear antibody pattern (ICAP) website (www.ANApatterns.org). To facilitate continuous improvement and input, specific comments on ICAP are encouraged and these will be discussed in subsequent ICAP meetings. The ultimate goal with the establishment of the ICAP is to promote harmonization and understanding of autoantibody test nomenclature, as well as interpretation guidelines for ANA testing, thereby optimizing usage in patient care.
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Affiliation(s)
- Edward K L Chan
- Department of Oral Biology, University of Florida , Gainesville, FL , USA
| | - Jan Damoiseaux
- Central Diagnostic Laboratory, Maastricht University Medical Center , Maastricht , Netherlands
| | - Orlando Gabriel Carballo
- Laboratory of Immunology, Hospital Carlos G. Durand , Buenos Aires , Argentina ; Department of Immunology, Instituto Universitario del Hospital Italiano , Buenos Aires , Argentina
| | - Karsten Conrad
- Institute of Immunology, Technical University of Dresden , Dresden , Germany
| | | | | | - Marvin J Fritzler
- Department of Medicine, Cumming School of Medicine, University of Calgary , Calgary, AB , Canada
| | - Ignacio Garcia-De La Torre
- Department of Immunology and Rheumatology, Hospital General de Occidente, University of Guadalajara , Guadalajara , Mexico
| | - Manfred Herold
- Department of Internal Medicine VI, Medical University of Innsbruck , Innsbruck , Austria
| | - Tsuneyo Mimori
- Department of the Control for Rheumatic Diseases, Graduate School of Medicine, Kyoto University , Kyoto , Japan ; Department of Rheumatology and Clinical Immunology, Graduate School of Medicine, Kyoto University , Kyoto , Japan
| | - Minoru Satoh
- Department of Clinical Nursing, University of Occupational and Environmental Health , Kitakyushu , Japan
| | | | - Luis E C Andrade
- Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de São Paulo , São Paulo , Brazil ; Immunology Division, Fleury Medicine and Health Laboratories , São Paulo , Brazil
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Chan EKL, Damoiseaux J, Carballo OG, Conrad K, de Melo Cruvinel W, Francescantonio PLC, Fritzler MJ, Garcia-De La Torre I, Herold M, Mimori T, Satoh M, von Mühlen CA, Andrade LEC. Report of the First International Consensus on Standardized Nomenclature of Antinuclear Antibody HEp-2 Cell Patterns 2014-2015. Front Immunol 2015; 6:412. [PMID: 26347739 PMCID: PMC4542633 DOI: 10.3389/fimmu.2015.00412] [Citation(s) in RCA: 216] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 07/27/2015] [Indexed: 12/30/2022] Open
Abstract
During the 12th International Workshop on Autoantibodies and Autoimmunity held in Sao Paulo, Brazil, on August 28, 2014, a full day session was devoted to establishing a consensus on the nomenclature of staining patterns observed in the antinuclear antibody (ANA) indirect immunofluorescence test on HEp-2 cells. The current report summarizes the collective agreements with input from the host Brazilian and international communities that represented research, clinical, and diagnostic service laboratories. Patterns are categorized in three major groups (nuclear, cytoplasmic, and mitotic patterns) and each pattern has been defined and described in detail. The consensus nomenclature and representative patterns are made available online at the international consensus on antinuclear antibody pattern (ICAP) website (www.ANApatterns.org). To facilitate continuous improvement and input, specific comments on ICAP are encouraged and these will be discussed in subsequent ICAP meetings. The ultimate goal with the establishment of the ICAP is to promote harmonization and understanding of autoantibody test nomenclature, as well as interpretation guidelines for ANA testing, thereby optimizing usage in patient care.
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Affiliation(s)
- Edward K. L. Chan
- Department of Oral Biology, University of Florida, Gainesville, FL, USA
| | - Jan Damoiseaux
- Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, Netherlands
| | - Orlando Gabriel Carballo
- Laboratory of Immunology, Hospital Carlos G. Durand, Buenos Aires, Argentina
- Department of Immunology, Instituto Universitario del Hospital Italiano, Buenos Aires, Argentina
| | - Karsten Conrad
- Institute of Immunology, Technical University of Dresden, Dresden, Germany
| | | | | | - Marvin J. Fritzler
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Ignacio Garcia-De La Torre
- Department of Immunology and Rheumatology, Hospital General de Occidente, University of Guadalajara, Guadalajara, Mexico
| | - Manfred Herold
- Department of Internal Medicine VI, Medical University of Innsbruck, Innsbruck, Austria
| | - Tsuneyo Mimori
- Department of the Control for Rheumatic Diseases, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Department of Rheumatology and Clinical Immunology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Minoru Satoh
- Department of Clinical Nursing, University of Occupational and Environmental Health, Kitakyushu, Japan
| | | | - Luis E. C. Andrade
- Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
- Immunology Division, Fleury Medicine and Health Laboratories, São Paulo, Brazil
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VRK1 regulates Cajal body dynamics and protects coilin from proteasomal degradation in cell cycle. Sci Rep 2015; 5:10543. [PMID: 26068304 PMCID: PMC4464288 DOI: 10.1038/srep10543] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 04/24/2015] [Indexed: 12/20/2022] Open
Abstract
Cajal bodies (CBs) are nuclear organelles associated with ribonucleoprotein functions and RNA maturation. CBs are assembled on coilin, its main scaffold protein, in a cell cycle dependent manner. The Ser-Thr VRK1 (vaccinia-related kinase 1) kinase, whose activity is also cell cycle regulated, interacts with and phosphorylates coilin regulating assembly of CBs. Coilin phosphorylation is not necessary for its interaction with VRK1, but it occurs in mitosis and regulates coilin stability. Knockdown of VRK1 or VRK1 inactivation by serum deprivation causes a loss of coilin phosphorylation in Ser184 and of CBs formation, which are rescued with an active VRK1, but not by kinase-dead VRK1. The phosphorylation of coilin in Ser184 occurs during mitosis before assembly of CBs. Loss of coilin phosphorylation results in disintegration of CBs, and of coilin degradation that is prevented by proteasome inhibitors. After depletion of VRK1, coilin is ubiquitinated in nuclei, which is partly mediated by mdm2, but its proteasomal degradation occurs in cytosol and is prevented by blocking its nuclear export. We conclude that VRK1 is a novel regulator of CBs dynamics and stability in cell cycle by protecting coilin from ubiquitination and degradation in the proteasome, and propose a model of CB dynamics.
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41
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Förthmann B, Grothe C, Claus P. A nuclear odyssey: fibroblast growth factor-2 (FGF-2) as a regulator of nuclear homeostasis in the nervous system. Cell Mol Life Sci 2015; 72:1651-62. [PMID: 25552245 PMCID: PMC11113852 DOI: 10.1007/s00018-014-1818-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 12/10/2014] [Accepted: 12/19/2014] [Indexed: 01/07/2023]
Abstract
Nuclear localization of classical growth factors is a well-known phenomenon but still remains a molecular and cellular conundrum. Fibroblast growth factor-2 (FGF-2) is an excellent example of a protein which functions as an extracellular molecule involved in canonical receptor tyrosine kinase signaling as well as displaying intracellular functions. Paracrine and nuclear functions are two important sides of the same protein. FGF-2 is expressed in isoforms with different molecular weights from one mRNA species. In rodents, all of these isoforms become imported to the nucleus. In this review, we discuss structural and functional aspects of FGF-2 isoforms in the nervous system. The nuclear odyssey of FGF-2 is reflected by nuclear dynamics, localization to nuclear bodies such as nucleoli, binding to chromatin and engagement in various protein interactions. Recently discovered molecular partnerships of the isoforms shed light on their nuclear functions, thereby greatly extending our knowledge of the multifaceted functions of FGF-2.
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Affiliation(s)
- Benjamin Förthmann
- Department of Neuroanatomy, Institute of Neuroanatomy, Hannover Medical School, OE 4140, Carl-Neuberg-Str.1, 30625 Hannover, Germany
| | - Claudia Grothe
- Department of Neuroanatomy, Institute of Neuroanatomy, Hannover Medical School, OE 4140, Carl-Neuberg-Str.1, 30625 Hannover, Germany
- Center for Systems Neuroscience, 30625 Hannover, Germany
| | - Peter Claus
- Department of Neuroanatomy, Institute of Neuroanatomy, Hannover Medical School, OE 4140, Carl-Neuberg-Str.1, 30625 Hannover, Germany
- Center for Systems Neuroscience, 30625 Hannover, Germany
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42
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Enwerem II, Wu G, Yu YT, Hebert MD. Cajal body proteins differentially affect the processing of box C/D scaRNPs. PLoS One 2015; 10:e0122348. [PMID: 25875178 PMCID: PMC4395269 DOI: 10.1371/journal.pone.0122348] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 02/13/2015] [Indexed: 11/19/2022] Open
Abstract
Small nuclear ribonucleoproteins (snRNPs), which are required for pre-mRNA splicing, contain extensively modified snRNA. Small Cajal body-specific ribonucleoproteins (scaRNPs) mediate these modifications. It is unknown how the box C/D class of scaRNPs localizes to Cajal Bodies (CBs). The processing of box C/D scaRNA is also unclear. Here, we explore the processing of box C/D scaRNA 2 and 9 by coilin. We also broaden our investigation to include WRAP53 and SMN, which accumulate in CBs, play a role in RNP biogenesis and associate with coilin. These studies demonstrate that the processing of an ectopically expressed scaRNA2 is altered upon the reduction of coilin, WRAP53 or SMN, but the extent and direction of this change varies depending on the protein reduced. We also show that box C/D scaRNP activity is reduced in a cell line derived from coilin knockout mice. Collectively, the findings presented here further implicate coilin as being a direct participant in the formation of box C/D scaRNPs, and demonstrate that WRAP53 and SMN may also play a role, but the activity of these proteins is divergent to coilin.
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Affiliation(s)
- Isioma I. Enwerem
- Department of Biochemistry, The University of Mississippi Medical Center, Jackson, Mississippi 39216–4505, United States of America
| | - Guowei Wu
- Department of Biochemistry and Biophysics, The University of Rochester Medical Center, Rochester, New York 14642, United States of America
| | - Yi Tao Yu
- Department of Biochemistry and Biophysics, The University of Rochester Medical Center, Rochester, New York 14642, United States of America
| | - Michael D. Hebert
- Department of Biochemistry, The University of Mississippi Medical Center, Jackson, Mississippi 39216–4505, United States of America
- * E-mail:
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Rüegger S, Miki TS, Hess D, Großhans H. The ribonucleotidyl transferase USIP-1 acts with SART3 to promote U6 snRNA recycling. Nucleic Acids Res 2015; 43:3344-57. [PMID: 25753661 PMCID: PMC4381082 DOI: 10.1093/nar/gkv196] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 02/24/2015] [Indexed: 02/02/2023] Open
Abstract
The spliceosome is a large molecular machine that serves to remove the intervening sequences that are present in most eukaryotic pre-mRNAs. At its core are five small nuclear ribonucleoprotein complexes, the U1, U2, U4, U5 and U6 snRNPs, which undergo dynamic rearrangements during splicing. Their reutilization for subsequent rounds of splicing requires reversion to their original configurations, but little is known about this process. Here, we show that ZK863.4/USIP-1 (U Six snRNA-Interacting Protein-1) is a ribonucleotidyl transferase that promotes accumulation of the Caenorhabditis elegans U6 snRNA. Endogenous USIP-1–U6 snRNA complexes lack the Lsm proteins that constitute the protein core of the U6 snRNP, but contain the U6 snRNP recycling factor SART3/B0035.12. Furthermore, co-immunoprecipitation experiments suggest that SART3 but not USIP-1 occurs also in a separate complex containing both the U4 and U6 snRNPs. Based on this evidence, genetic interaction between usip-1 and sart-3, and the apparent dissociation of Lsm proteins from the U6 snRNA during spliceosome activation, we propose that USIP-1 functions upstream of SART3 to promote U6 snRNA recycling.
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Affiliation(s)
- Stefan Rüegger
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland University of Basel, Petersplatz 1, CH-4003 Basel, Switzerland
| | - Takashi S Miki
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
| | - Daniel Hess
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
| | - Helge Großhans
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
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44
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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] [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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45
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Bogolyubova I, Lyabin D, Bogolyubov D, Ovchinnikov L. Immunocytochemical study of YB-1 nuclear distribution in different cell types. Tissue Cell 2014; 46:457-61. [DOI: 10.1016/j.tice.2014.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 07/17/2014] [Accepted: 08/06/2014] [Indexed: 12/23/2022]
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46
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Khodyuchenko TA, Krasikova AV. Cajal bodies and histone locus bodies: Molecular composition and function. Russ J Dev Biol 2014. [DOI: 10.1134/s106236041406006x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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47
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Mani RS. The emerging role of speckle-type POZ protein (SPOP) in cancer development. Drug Discov Today 2014; 19:1498-502. [PMID: 25058385 DOI: 10.1016/j.drudis.2014.07.009] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 07/15/2014] [Indexed: 11/24/2022]
Abstract
Speckle-type POZ (pox virus and zinc finger protein) protein (SPOP) is an E3 ubiquitin ligase adaptor protein that is frequently mutated in prostate and endometrial cancers. All the cancer-associated SPOP mutations reported to date are clustered in the meprin and TRAF (Tumor necrosis factor receptor-associated factor) homology (MATH) domain, presumably affecting substrate binding. SPOP mutations in prostate cancer are mutually exclusive with the ETS (Erythroblast transformation-specific) family gene rearrangements and define a distinct molecular subclass of prostate cancer. SPOP mutations contribute to prostate cancer development by altering the steady-state levels of key components in the androgen-signaling pathway.
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Affiliation(s)
- Ram-Shankar Mani
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA; Department of Urology, UT Southwestern Medical Center, Dallas, TX, USA.
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48
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Bártová E, Foltánková V, Legartová S, Sehnalová P, Sorokin DV, Suchánková J, Kozubek S. Coilin is rapidly recruited to UVA-induced DNA lesions and γ-radiation affects localized movement of Cajal bodies. Nucleus 2014; 5:460-8. [PMID: 24859326 DOI: 10.4161/nucl.29229] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cajal bodies are important nuclear structures containing proteins that preferentially regulate RNA-related metabolism. We investigated the cell-type specific nuclear distribution of Cajal bodies and the level of coilin, a protein of Cajal bodies, in non-irradiated and irradiated human tumor cell lines and embryonic stem (ES) cells. Cajal bodies were localized in different nuclear compartments, including DAPI-poor regions, in the proximity of chromocenters, and adjacent to nucleoli. The number of Cajal bodies per nucleus was cell cycle-dependent, with higher numbers occurring during G2 phase. Human ES cells contained a high coilin level in the nucleoplasm, but coilin-positive Cajal bodies were also identified in nuclei of mouse and human ES cells. Coilin, but not SMN, recognized UVA-induced DNA lesions, which was cell cycle-independent. Treatment with γ-radiation reduced the localized movement of Cajal bodies in many cell types and GFP-coilin fluorescence recovery after photobleaching was very fast in nucleoplasm in comparison with GFP-coilin recovery in DNA lesions. By contrast, nucleolus-localized coilin displayed very slow fluorescence recovery after photobleaching, which indicates very slow rates of protein diffusion, especially in nucleoli of mouse ES cells.
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Affiliation(s)
- Eva Bártová
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Veronika Foltánková
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Soňa Legartová
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Petra Sehnalová
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Dmitry V Sorokin
- Faculty of Informatics; Masaryk University; Brno, Czech Republic
| | - Jana Suchánková
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Stanislav Kozubek
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
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49
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Abstract
This review summarizes the current understanding of the role of nuclear bodies in regulating gene expression. The compartmentalization of cellular processes, such as ribosome biogenesis, RNA processing, cellular response to stress, transcription, modification and assembly of spliceosomal snRNPs, histone gene synthesis and nuclear RNA retention, has significant implications for gene regulation. These functional nuclear domains include the nucleolus, nuclear speckle, nuclear stress body, transcription factory, Cajal body, Gemini of Cajal body, histone locus body and paraspeckle. We herein review the roles of nuclear bodies in regulating gene expression and their relation to human health and disease.
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Affiliation(s)
| | - Cornelius F. Boerkoel
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-604-875-2157; Fax: +1-604-875-2376
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Carcamo WC, Calise SJ, von Mühlen CA, Satoh M, Chan EKL. Molecular cell biology and immunobiology of mammalian rod/ring structures. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 308:35-74. [PMID: 24411169 DOI: 10.1016/b978-0-12-800097-7.00002-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Nucleotide biosynthesis is a highly regulated process necessary for cell growth and replication. Cytoplasmic structures in mammalian cells, provisionally described as rods and rings (RR), were identified by human autoantibodies and recently shown to include two key enzymes of the CTP/GTP biosynthetic pathways, cytidine triphosphate synthetase (CTPS) and inosine monophosphate dehydrogenase (IMPDH). Several studies have described CTPS filaments in mammalian cells, Drosophila, yeast, and bacteria. Other studies have identified IMPDH filaments in mammalian cells. Similarities among these studies point to a common evolutionarily conserved cytoplasmic structure composed of a subset of nucleotide biosynthetic enzymes. These structures appear to be a conserved metabolic response to decreased intracellular GTP and/or CTP pools. Antibodies to RR were found to develop in some hepatitis C patients treated with interferon-α and ribavirin. Additionally, the presence of anti-RR antibodies was correlated with poor treatment outcome.
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Affiliation(s)
- Wendy C Carcamo
- Department of Oral Biology, University of Florida, Gainesville, Florida, USA
| | - S John Calise
- Department of Oral Biology, University of Florida, Gainesville, Florida, USA
| | | | - Minoru Satoh
- Division of Rheumatology and Clinical Immunology, Department of Medicine, University of Florida, Gainesville, Florida, USA; Department of Clinical Nursing, School of Health Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Edward K L Chan
- Department of Oral Biology, University of Florida, Gainesville, Florida, USA.
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