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Chakraborty S, Mishra J, Roy A, Niharika, Manna S, Baral T, Nandi P, Patra S, Patra SK. Liquid-liquid phase separation in subcellular assemblages and signaling pathways: Chromatin modifications induced gene regulation for cellular physiology and functions including carcinogenesis. Biochimie 2024; 223:74-97. [PMID: 38723938 DOI: 10.1016/j.biochi.2024.05.007] [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: 12/06/2023] [Revised: 03/08/2024] [Accepted: 05/04/2024] [Indexed: 05/24/2024]
Abstract
Liquid-liquid phase separation (LLPS) describes many biochemical processes, including hydrogel formation, in the integrity of macromolecular assemblages and existence of membraneless organelles, including ribosome, nucleolus, nuclear speckles, paraspeckles, promyelocytic leukemia (PML) bodies, Cajal bodies (all exert crucial roles in cellular physiology), and evidence are emerging day by day. Also, phase separation is well documented in generation of plasma membrane subdomains and interplay between membranous and membraneless organelles. Intrinsically disordered regions (IDRs) of biopolymers/proteins are the most critical sticking regions that aggravate the formation of such condensates. Remarkably, phase separated condensates are also involved in epigenetic regulation of gene expression, chromatin remodeling, and heterochromatinization. Epigenetic marks on DNA and histones cooperate with RNA-binding proteins through their IDRs to trigger LLPS for facilitating transcription. How phase separation coalesces mutant oncoproteins, orchestrate tumor suppressor genes expression, and facilitated cancer-associated signaling pathways are unravelling. That autophagosome formation and DYRK3-mediated cancer stem cell modification also depend on phase separation is deciphered in part. In view of this, and to linchpin insight into the subcellular membraneless organelle assembly, gene activation and biological reactions catalyzed by enzymes, and the downstream physiological functions, and how all these events are precisely facilitated by LLPS inducing organelle function, epigenetic modulation of gene expression in this scenario, and how it goes awry in cancer progression are summarized and presented in this article.
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Affiliation(s)
- Subhajit Chakraborty
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Jagdish Mishra
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Ankan Roy
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Niharika
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Soumen Manna
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Tirthankar Baral
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Piyasa Nandi
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Subhajit Patra
- Department of Chemical Engineering, Maulana Azad National Institute of Technology, Bhopal, India
| | - Samir Kumar Patra
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India.
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Engbrecht M, Grundei D, Dilger AM, Wiedemann H, Aust AK, Baumgärtner S, Helfrich S, Kergl-Räpple F, Bürkle A, Mangerich A. Monitoring nucleolar-nucleoplasmic protein shuttling in living cells by high-content microscopy and automated image analysis. Nucleic Acids Res 2024:gkae598. [PMID: 39036969 DOI: 10.1093/nar/gkae598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 05/25/2024] [Accepted: 06/26/2024] [Indexed: 07/23/2024] Open
Abstract
The nucleolus has core functions in ribosome biosynthesis, but also acts as a regulatory hub in a plethora of non-canonical processes, including cellular stress. Upon DNA damage, several DNA repair factors shuttle between the nucleolus and the nucleoplasm. Yet, the molecular mechanisms underlying such spatio-temporal protein dynamics remain to be deciphered. Here, we present a novel imaging platform to investigate nucleolar-nucleoplasmic protein shuttling in living cells. For image acquisition, we used a commercially available automated fluorescence microscope and for image analysis, we developed a KNIME workflow with implementation of machine learning-based tools. We validated the method with different nucleolar proteins, i.e., PARP1, TARG1 and APE1, by monitoring their shuttling dynamics upon oxidative stress. As a paradigm, we analyzed PARP1 shuttling upon H2O2 treatment in combination with a range of pharmacological inhibitors in a novel reporter cell line. These experiments revealed that inhibition of SIRT7 results in a loss of nucleolar PARP1 localization. Finally, we unraveled specific differences in PARP1 shuttling dynamics after co-treatment with H2O2 and different clinical PARP inhibitors. Collectively, this work delineates a highly sensitive and versatile bioimaging platform to investigate swift nucleolar-nucleoplasmic protein shuttling in living cells, which can be employed for pharmacological screening and in-depth mechanistic analyses.
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Affiliation(s)
- Marina Engbrecht
- Molecular Toxicology, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - David Grundei
- Molecular Toxicology, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Asisa M Dilger
- Nutritional Toxicology, Institute of Nutritional Science, University of Potsdam, 14469 Potsdam, Germany
| | - Hannah Wiedemann
- Molecular Toxicology, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Ann-Kristin Aust
- Molecular Toxicology, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Sarah Baumgärtner
- Molecular Toxicology, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | | | | | - Alexander Bürkle
- Molecular Toxicology, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Aswin Mangerich
- Molecular Toxicology, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
- Nutritional Toxicology, Institute of Nutritional Science, University of Potsdam, 14469 Potsdam, Germany
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3
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González-Arzola K. The nucleolus: Coordinating stress response and genomic stability. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2024; 1867:195029. [PMID: 38642633 DOI: 10.1016/j.bbagrm.2024.195029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 03/25/2024] [Accepted: 04/12/2024] [Indexed: 04/22/2024]
Abstract
The perception that the nucleoli are merely the organelles where ribosome biogenesis occurs is challenged. Only around 30 % of nucleolar proteins are solely involved in producing ribosomes. Instead, the nucleolus plays a critical role in controlling protein trafficking during stress and, according to its dynamic nature, undergoes continuous protein exchange with nucleoplasm under various cellular stressors. Hence, the concept of nucleolar stress has evolved as cellular insults that disrupt the structure and function of the nucleolus. Considering the emerging role of this organelle in DNA repair and the fact that rDNAs are the most fragile genomic loci, therapies targeting the nucleoli are increasingly being developed. Besides, drugs that target ribosome synthesis and induce nucleolar stress can be used in cancer therapy. In contrast, agents that regulate nucleolar activity may be a potential treatment for neurodegeneration caused by abnormal protein accumulation in the nucleolus. Here, I explore the roles of nucleoli beyond their ribosomal functions, highlighting the factors triggering nucleolar stress and their impact on genomic stability.
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Affiliation(s)
- Katiuska González-Arzola
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Junta de Andalucía, Universidad Pablo de Olavide, 41092 Seville, Spain; Departamento de Bioquímica Vegetal y Biología Molecular, Universidad de Sevilla, 41012 Seville, Spain.
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Trifault B, Mamontova V, Cossa G, Ganskih S, Wei Y, Hofstetter J, Bhandare P, Baluapuri A, Nieto B, Solvie D, Ade CP, Gallant P, Wolf E, Larsen DH, Munschauer M, Burger K. Nucleolar detention of NONO shields DNA double-strand breaks from aberrant transcripts. Nucleic Acids Res 2024; 52:3050-3068. [PMID: 38224452 PMCID: PMC11014278 DOI: 10.1093/nar/gkae022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 12/11/2023] [Accepted: 01/04/2024] [Indexed: 01/16/2024] Open
Abstract
RNA-binding proteins emerge as effectors of the DNA damage response (DDR). The multifunctional non-POU domain-containing octamer-binding protein NONO/p54nrb marks nuclear paraspeckles in unperturbed cells, but also undergoes re-localization to the nucleolus upon induction of DNA double-strand breaks (DSBs). However, NONO nucleolar re-localization is poorly understood. Here we show that the topoisomerase II inhibitor etoposide stimulates the production of RNA polymerase II-dependent, DNA damage-inducible antisense intergenic non-coding RNA (asincRNA) in human cancer cells. Such transcripts originate from distinct nucleolar intergenic spacer regions and form DNA-RNA hybrids to tether NONO to the nucleolus in an RNA recognition motif 1 domain-dependent manner. NONO occupancy at protein-coding gene promoters is reduced by etoposide, which attenuates pre-mRNA synthesis, enhances NONO binding to pre-mRNA transcripts and is accompanied by nucleolar detention of a subset of such transcripts. The depletion or mutation of NONO interferes with detention and prolongs DSB signalling. Together, we describe a nucleolar DDR pathway that shields NONO and aberrant transcripts from DSBs to promote DNA repair.
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Affiliation(s)
- Barbara Trifault
- Mildred Scheel Early Career Center for Cancer Research (Mildred-Scheel-Nachwuchszentrum, MSNZ) Würzburg, University Hospital Würzburg, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Victoria Mamontova
- Mildred Scheel Early Career Center for Cancer Research (Mildred-Scheel-Nachwuchszentrum, MSNZ) Würzburg, University Hospital Würzburg, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Giacomo Cossa
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Sabina Ganskih
- Helmholtz Institute for RNA-based Infection Research, Helmholtz-Center for Infection Research, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
| | - Yuanjie Wei
- Helmholtz Institute for RNA-based Infection Research, Helmholtz-Center for Infection Research, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
| | - Julia Hofstetter
- Cancer Systems Biology Group, Theodor Boveri Institute, Biocenter, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Pranjali Bhandare
- Cancer Systems Biology Group, Theodor Boveri Institute, Biocenter, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Apoorva Baluapuri
- Cancer Systems Biology Group, Theodor Boveri Institute, Biocenter, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Blanca Nieto
- Nucleolar Stress and Disease Group, Danish Cancer Institute, Strandboulevarden 49, Copenhagen, Denmark
| | - Daniel Solvie
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Carsten P Ade
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Peter Gallant
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Elmar Wolf
- Cancer Systems Biology Group, Theodor Boveri Institute, Biocenter, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Dorthe H Larsen
- Nucleolar Stress and Disease Group, Danish Cancer Institute, Strandboulevarden 49, Copenhagen, Denmark
| | - Mathias Munschauer
- Helmholtz Institute for RNA-based Infection Research, Helmholtz-Center for Infection Research, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
| | - Kaspar Burger
- Mildred Scheel Early Career Center for Cancer Research (Mildred-Scheel-Nachwuchszentrum, MSNZ) Würzburg, University Hospital Würzburg, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
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Batnasan E, Kärkkäinen M, Koivukoski S, Sadeesh N, Tollis S, Ruusuvuori P, Scaravilli M, Latonen L. Platinum-based drugs induce phenotypic alterations in nucleoli and Cajal bodies in prostate cancer cells. Cancer Cell Int 2024; 24:29. [PMID: 38218884 PMCID: PMC10790272 DOI: 10.1186/s12935-023-03205-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 12/28/2023] [Indexed: 01/15/2024] Open
Abstract
PURPOSE Platinum-based drugs are cytotoxic drugs commonly used in cancer treatment. They cause DNA damage, effects of which on chromatin and cellular responses are relatively well described. Yet, the nuclear stress responses related to RNA processing are incompletely known and may be relevant for the heterogeneity with which cancer cells respond to these drugs. Here, we determine the type and extent of nuclear stress responses of prostate cancer cells to clinically relevant platinum drugs. METHODS We study nucleolar and Cajal body (CB) responses to cisplatin, carboplatin, and oxaliplatin with immunofluorescence-based methods in prostate cancer cells. We utilize organelle-specific markers NPM, Fibrillarin, Coilin, and SMN1, and study CB-regulatory proteins FUS and TDP-43 using siRNA-mediated downregulation. RESULTS Different types of prostate cancer cells have different sensitivities to platinum drugs. With equally cytotoxic doses, cisplatin, and oxaliplatin induce prominent nucleolar and CB stress responses while the nuclear stress phenotypes to carboplatin are milder. We find that Coilin is a stress-specific marker for platinum drug response heterogeneity. We also find that CB-associated, stress-responsive RNA binding proteins FUS and TDP-43 control Coilin and CB biology in prostate cancer cells and, further, that TDP-43 is associated with stress-responsive CBs in prostate cancer cells. CONCLUSION Our findings provide insight into the heterologous responses of prostate cancer cells to different platinum drug treatments and indicate Coilin and TDP-43 as stress mediators in the varied outcomes. These results help understand cancer drug responses at a cellular level and have implications in tackling heterogeneity in cancer treatment outcomes.
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Affiliation(s)
- Enkhzaya Batnasan
- Institute of Biomedicine, University of Eastern Finland, 1627, 70211, Kuopio, Finland
| | - Minttu Kärkkäinen
- Institute of Biomedicine, University of Eastern Finland, 1627, 70211, Kuopio, Finland
| | - Sonja Koivukoski
- Institute of Biomedicine, University of Eastern Finland, 1627, 70211, Kuopio, Finland
| | - Nithin Sadeesh
- Institute of Biomedicine, University of Eastern Finland, 1627, 70211, Kuopio, Finland
| | - Sylvain Tollis
- Institute of Biomedicine, University of Eastern Finland, 1627, 70211, Kuopio, Finland
| | | | - Mauro Scaravilli
- Institute of Biomedicine, University of Eastern Finland, 1627, 70211, Kuopio, Finland
| | - Leena Latonen
- Institute of Biomedicine, University of Eastern Finland, 1627, 70211, Kuopio, Finland.
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Huang Y, Liu Y, Guo X, Fan C, Yi C, Shi Q, Su H, Liu C, Yuan J, Liu D, Yang W, Han F. New insights on the evolution of nucleolar dominance in newly resynthesized hexaploid wheat Triticum zhukovskyi. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 115:1298-1315. [PMID: 37246611 DOI: 10.1111/tpj.16320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/11/2023] [Accepted: 05/23/2023] [Indexed: 05/30/2023]
Abstract
Nucleolar dominance (ND) is a widespread epigenetic phenomenon in hybridizations where nucleolus transcription fails at the nucleolus organizer region (NOR). However, the dynamics of NORs during the formation of Triticum zhukovskyi (GGAu Au Am Am ), another evolutionary branch of allohexaploid wheat, remains poorly understood. Here, we elucidated genetic and epigenetic changes occurring at the NOR loci within the Am , G, and D subgenomes during allopolyploidization by synthesizing hexaploid wheat GGAu Au Am Am and GGAu Au DD. In T. zhukovskyi, Au genome NORs from T. timopheevii (GGAu Au ) were lost, while the second incoming NORs from T. monococcum (Am Am ) were retained. Analysis of the synthesized T. zhukovskyi revealed that rRNA genes from the Am genome were silenced in F1 hybrids (GAu Am ) and remained inactive after genome doubling and subsequent self-pollinations. We observed increased DNA methylation accompanying the inactivation of NORs in the Am genome and found that silencing of NORs in the S1 generation could be reversed by a cytidine methylase inhibitor. Our findings provide insights into the ND process during the evolutionary period of T. zhukovskyi and highlight that inactive rDNA units may serve as a 'first reserve' in the form of R-loops, contributing to the successful evolution of T. zhukovskyi.
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Affiliation(s)
- Yuhong Huang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yang Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xianrui Guo
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chaolan Fan
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Congyang Yi
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qinghua Shi
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Handong Su
- Huazhong Agricultural University, Hubei, 430070, China
| | - Chang Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jing Yuan
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Dengcai Liu
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Wuyun Yang
- Crop Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, China
| | - Fangpu Han
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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Hoffmann G, López-González S, Mahboubi A, Hanson J, Hafrén A. Cauliflower mosaic virus protein P6 is a multivalent node for RNA granule proteins and interferes with stress granule responses during plant infection. THE PLANT CELL 2023; 35:3363-3382. [PMID: 37040611 PMCID: PMC10473198 DOI: 10.1093/plcell/koad101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 03/06/2023] [Accepted: 03/22/2023] [Indexed: 06/19/2023]
Abstract
Biomolecular condensation is a multipurpose cellular process that viruses use ubiquitously during their multiplication. Cauliflower mosaic virus replication complexes are condensates that differ from those of most viruses, as they are nonmembranous assemblies that consist of RNA and protein, mainly the viral protein P6. Although these viral factories (VFs) were described half a century ago, with many observations that followed since, functional details of the condensation process and the properties and relevance of VFs have remained enigmatic. Here, we studied these issues in Arabidopsis thaliana and Nicotiana benthamiana. We observed a large dynamic mobility range of host proteins within VFs, while the viral matrix protein P6 is immobile, as it represents the central node of these condensates. We identified the stress granule (SG) nucleating factors G3BP7 and UBP1 family members as components of VFs. Similarly, as SG components localize to VFs during infection, ectopic P6 localizes to SGs and reduces their assembly after stress. Intriguingly, it appears that soluble rather than condensed P6 suppresses SG formation and mediates other essential P6 functions, suggesting that the increased condensation over the infection time-course may accompany a progressive shift in selected P6 functions. Together, this study highlights VFs as dynamic condensates and P6 as a complex modulator of SG responses.
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Affiliation(s)
- Gesa Hoffmann
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
- Linnean Center for Plant Biology, 75007 Uppsala, Sweden
| | - Silvia López-González
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
- Linnean Center for Plant Biology, 75007 Uppsala, Sweden
| | - Amir Mahboubi
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, 90736 Umeå, Sweden
| | - Johannes Hanson
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, 90736 Umeå, Sweden
| | - Anders Hafrén
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
- Linnean Center for Plant Biology, 75007 Uppsala, Sweden
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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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9
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Shakyawar SK, Mishra NK, Vellichirammal NN, Cary L, Helikar T, Powers R, Oberley-Deegan RE, Berkowitz DB, Bayles KW, Singh VK, Guda C. A Review of Radiation-Induced Alterations of Multi-Omic Profiles, Radiation Injury Biomarkers, and Countermeasures. Radiat Res 2023; 199:89-111. [PMID: 36368026 PMCID: PMC10279411 DOI: 10.1667/rade-21-00187.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 10/24/2022] [Indexed: 11/13/2022]
Abstract
Increasing utilization of nuclear power enhances the risks associated with industrial accidents, occupational hazards, and the threat of nuclear terrorism. Exposure to ionizing radiation interferes with genomic stability and gene expression resulting in the disruption of normal metabolic processes in cells and organs by inducing complex biological responses. Exposure to high-dose radiation causes acute radiation syndrome, which leads to hematopoietic, gastrointestinal, cerebrovascular, and many other organ-specific injuries. Altered genomic variations, gene expression, metabolite concentrations, and microbiota profiles in blood plasma or tissue samples reflect the whole-body radiation injuries. Hence, multi-omic profiles obtained from high-resolution omics platforms offer a holistic approach for identifying reliable biomarkers to predict the radiation injury of organs and tissues resulting from radiation exposures. In this review, we performed a literature search to systematically catalog the radiation-induced alterations from multi-omic studies and radiation countermeasures. We covered radiation-induced changes in the genomic, transcriptomic, proteomic, metabolomic, lipidomic, and microbiome profiles. Furthermore, we have covered promising multi-omic biomarkers, FDA-approved countermeasure drugs, and other radiation countermeasures that include radioprotectors and radiomitigators. This review presents an overview of radiation-induced alterations of multi-omics profiles and biomarkers, and associated radiation countermeasures.
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Affiliation(s)
- Sushil K Shakyawar
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Nitish K Mishra
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Neetha N Vellichirammal
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Lynnette Cary
- Division of Radioprotectants, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Tomáš Helikar
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln NE 65888, USA
| | - Robert Powers
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln NE 65888, USA
- Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln NE 68588, USA
| | - Rebecca E Oberley-Deegan
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - David B Berkowitz
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln NE 65888, USA
| | - Kenneth W Bayles
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Vijay K Singh
- Division of Radioprotectants, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Chittibabu Guda
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Center for Biomedical Informatics Research and Innovation, University of Nebraska Medical Center, Omaha, NE 68198, USA
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10
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Muciño-Hernández G, Acevo-Rodríguez PS, Cabrera-Benitez S, Guerrero AO, Merchant-Larios H, Castro-Obregón S. Nucleophagy contributes to genome stability through degradation of type II topoisomerases A and B and nucleolar components. J Cell Sci 2023; 136:286548. [PMID: 36633090 PMCID: PMC10112964 DOI: 10.1242/jcs.260563] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 11/24/2022] [Indexed: 01/13/2023] Open
Abstract
The nuclear architecture of mammalian cells can be altered as a consequence of anomalous accumulation of nuclear proteins or genomic alterations. Most of the knowledge about nuclear dynamics comes from studies on cancerous cells. How normal healthy cells maintain genome stability, avoiding accumulation of nuclear damaged material, is less understood. Here, we describe that primary mouse embryonic fibroblasts develop a basal level of nuclear buds and micronuclei, which increase after etoposide-induced DNA double-stranded breaks. Both basal and induced nuclear buds and micronuclei colocalize with the autophagic proteins BECN1 and LC3B (also known as MAP1LC3B) and with acidic vesicles, suggesting their clearance by nucleophagy. Some of the nuclear alterations also contain autophagic proteins and type II DNA topoisomerases (TOP2A and TOP2B), or the nucleolar protein fibrillarin, implying they are also targets of nucleophagy. We propose that basal nucleophagy contributes to genome and nuclear stability, as well as in response to DNA damage.
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Affiliation(s)
- Gabriel Muciño-Hernández
- Departamento de Neurodesarrollo y Fisiología, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 Mexico City, México
| | - Pilar Sarah Acevo-Rodríguez
- Departamento de Neurodesarrollo y Fisiología, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 Mexico City, México
| | - Sandra Cabrera-Benitez
- Facultad de Ciencias, Universidad Nacional Autónoma de México, 04510 Mexico City, México
| | - Adán Oswaldo Guerrero
- Laboratorio Nacional de Microscopía Avanzada, Instituto de Biotecnología, Universidad Nacional Autónoma de México, 62210 Cuernavaca, Morelos, Mexico
| | - Horacio Merchant-Larios
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510 Mexico City, Mexico
| | - Susana Castro-Obregón
- Departamento de Neurodesarrollo y Fisiología, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 Mexico City, México
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11
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Regulation of RNA Polymerase I Stability and Function. Cancers (Basel) 2022; 14:cancers14235776. [PMID: 36497261 PMCID: PMC9737084 DOI: 10.3390/cancers14235776] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 11/21/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022] Open
Abstract
RNA polymerase I is a highly processive enzyme with fast initiation and elongation rates. The structure of Pol I, with its in-built RNA cleavage ability and incorporation of subunits homologous to transcription factors, enables it to quickly and efficiently synthesize the enormous amount of rRNA required for ribosome biogenesis. Each step of Pol I transcription is carefully controlled. However, cancers have highjacked these control points to switch the enzyme, and its transcription, on permanently. While this provides an exceptional benefit to cancer cells, it also creates a potential cancer therapeutic vulnerability. We review the current research on the regulation of Pol I transcription, and we discuss chemical biology efforts to develop new targeted agents against this process. Lastly, we highlight challenges that have arisen from the introduction of agents with promiscuous mechanisms of action and provide examples of agents with specificity and selectivity against Pol I.
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12
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Yan D, Hua L. Nucleolar stress: Friend or foe in cardiac function? Front Cardiovasc Med 2022; 9:1045455. [PMID: 36386352 PMCID: PMC9659567 DOI: 10.3389/fcvm.2022.1045455] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/17/2022] [Indexed: 03/14/2024] Open
Abstract
Studies in the past decades have uncovered an emerging role of the nucleolus in stress response and human disease progression. The disruption of ribosome biogenesis in the nucleolus causes aberrant nucleolar architecture and function, termed nucleolar stress, to initiate stress-responsive pathways via nucleolar release sequestration of various proteins. While data obtained from both clinical and basic investigations have faithfully demonstrated an involvement of nucleolar stress in the pathogenesis of cardiomyopathy, much remains unclear regarding its precise role in the progression of cardiac diseases. On the one hand, the initiation of nucleolar stress following acute myocardial damage leads to the upregulation of various cardioprotective nucleolar proteins, including nucleostemin (NS), nucleophosmin (NPM) and nucleolin (NCL). As a result, nucleolar stress plays an important role in facilitating the survival and repair of cardiomyocytes. On the other hand, abnormalities in nucleolar architecture and function are correlated with the deterioration of cardiac diseases. Notably, the cardiomyocytes of advanced ischemic and dilated cardiomyopathy display impaired silver-stained nucleolar organiser regions (AgNORs) and enlarged nucleoli, resembling the characteristics of tissue aging. Collectively, nucleolar abnormalities are critically involved in the development of cardiac diseases.
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Affiliation(s)
- Daliang Yan
- Department of Cardiovascular Surgery, Taizhou People’s Hospital, Taizhou, China
| | - Lu Hua
- Department of Oncology, Taizhou People’s Hospital, Taizhou, China
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13
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Kanekura K, Kuroda M. How can we interpret the relationship between liquid-liquid phase separation and amyotrophic lateral sclerosis? J Transl Med 2022; 102:912-918. [PMID: 36775420 DOI: 10.1038/s41374-022-00791-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/12/2022] [Indexed: 01/08/2023] Open
Abstract
One of the critical definitions of neurodegenerative diseases is the formation of insoluble intracellular inclusion body. These inclusions are found in various neurodegenerative diseases such as Alzheimer's disease, amyotrophic lateral sclerosis (ALS), Huntington's disease, Parkinson's disease, and frontotemporal dementia (FTD). Each inclusion body contains disease-specific proteins and is also resistant to common detergent treatments. These aggregates are generally ubiquitinated and thus recognized as misfolded by the organism. They are observed in residual neurons at the affected sites in each disease, suggesting a contribution to disease pathogenesis. The molecular mechanisms for the formation of these inclusion bodies remain unclear. Some proteins, such as superoxide dismutase 1 (SOD1) mutant that causes familial ALS, are highly aggregative due to altered folding caused by point mutations. Still, the aggregates observed in neurodegenerative diseases contain wild-type proteins. In recent years, it has been reported that the proteins responsible for neurodegenerative diseases undergo liquid-liquid phase separation (LLPS). In particular, the ALS/FTD causative proteins such as TAR DNA-binding protein 43 kDa (TDP-43) and fused-in-sarcoma (FUS) undergo LLPS. LLPS increases the local concentration of these proteins, and these proteins eventually change their phase from liquid to solid (liquid-solid phase transition) due to abnormal folding during repetitive separation cycles into two phases and recovery to one phase. In addition to the inclusion body formation, sequestration of essential proteins into the LLPS droplets or changes in the LLPS status can directly impair neural functions and cause diseases. In this review, we will discuss the relationship between the LLPS observed in ALS causative proteins and the pathogenesis of the disease and outline potential therapeutic approaches.
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Affiliation(s)
- Kohsuke Kanekura
- Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan.
| | - Masahiko Kuroda
- Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan
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14
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Trifault B, Mamontova V, Burger K. In vivo Proximity Labeling of Nuclear and Nucleolar Proteins by a Stably Expressed, DNA Damage-Responsive NONO-APEX2 Fusion Protein. Front Mol Biosci 2022; 9:914873. [PMID: 35733943 PMCID: PMC9207311 DOI: 10.3389/fmolb.2022.914873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/19/2022] [Indexed: 11/13/2022] Open
Abstract
Cellular stress can induce DNA lesions that threaten the stability of genes. The DNA damage response (DDR) recognises and repairs broken DNA to maintain genome stability. Intriguingly, components of nuclear paraspeckles like the non-POU domain containing octamer-binding protein (NONO) participate in the repair of DNA double-strand breaks (DSBs). NONO is a multifunctional RNA-binding protein (RBP) that facilitates the retention and editing of messenger (m)RNA as well as pre-mRNA processing. However, the role of NONO in the DDR is poorly understood. Here, we establish a novel human U2OS cell line that expresses NONO fused to the engineered ascorbate peroxidase 2 (U2OS:NONO-APEX2-HA). We show that NONO-APEX2-HA accumulates in the nucleolus in response to DNA damage. Combining viability assays, subcellular localisation studies, coimmunoprecipitation experiments and in vivo proximity labeling, we demonstrate that NONO-APEX2-HA is a stably expressed fusion protein that mimics endogenous NONO in terms of expression, localisation and bona fide interactors. We propose that in vivo proximity labeling in U2OS:NONO-APEX2-HA cells is capable for the assessment of NONO interactomes by downstream assays. U2OS:NONO-APEX2-HA cells will likely be a valuable resource for the investigation of NONO interactome dynamics in response to DNA damage and other stimuli.
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15
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Rastorgueva E, Liamina D, Panchenko I, Iurova E, Beloborodov E, Pogodina E, Dmitrii S, Slesarev S, Saenko Y. The effect of chromosome abnormalities on expression of SnoRNA in radioresistant and radiosensitive cell lines after irradiation. Cancer Biomark 2022; 34:545-553. [PMID: 35275519 DOI: 10.3233/cbm-210092] [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: 11/02/2022]
Abstract
In this paper, we have studied the role of chromosomal abnormalities in the expression of small nucleolar RNAs (snoRNAs) of radioresistant (K562) and radiosensitive (HL-60) leukemia cell line. Cells were exposed to an X-ray dose of 4 Gy. SnoRNA expression was investigated using NGS sequencing. The distribution of expressed snoRNAs on chromosomes has been found to be different for two cell lines. The most significant differences in the expression of snoRNAs were found in the K562 cell line based on the analysis of the dynamics of log2fc values. The type of clustering, the number and type of snoRNAs slightly differed in the chromosomes with trisomy and monosomy and had a pronounced difference in pairs with marker chromosomes in both cell lines. In this study, we have demonstrated that chromosomal abnormalities alter the expression of snoRNA after irradiation. Trisomies and monosomies do not have such a noticeable effect on the expression of snoRNAs as the presence of marker chromosomes.
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Affiliation(s)
- Eugenia Rastorgueva
- Laboratory of Molecular and Cell Biology, S.P. Kapitsa Research Institute of Technology, Ulyanovsk State University, Ulyanovsk, Russian.,Department of General and Clinical Pharmacology and Microbiology, Faculty of Medicine, Ulyanovsk State University, Ulyanovsk, Russian
| | - Daria Liamina
- Laboratory of Molecular and Cell Biology, S.P. Kapitsa Research Institute of Technology, Ulyanovsk State University, Ulyanovsk, Russian
| | - Ivan Panchenko
- Second Surgical Department, Ulyanovsk Oncology Center, Ulyanovsk, Russian
| | - Elena Iurova
- Laboratory of Molecular and Cell Biology, S.P. Kapitsa Research Institute of Technology, Ulyanovsk State University, Ulyanovsk, Russian
| | - Evgenii Beloborodov
- Laboratory of Molecular and Cell Biology, S.P. Kapitsa Research Institute of Technology, Ulyanovsk State University, Ulyanovsk, Russian
| | - Evgeniya Pogodina
- Laboratory of Molecular and Cell Biology, S.P. Kapitsa Research Institute of Technology, Ulyanovsk State University, Ulyanovsk, Russian
| | - Sugak Dmitrii
- Laboratory of Molecular and Cell Biology, S.P. Kapitsa Research Institute of Technology, Ulyanovsk State University, Ulyanovsk, Russian
| | - Sergei Slesarev
- Department of Biology, Ecology and Natural Resources Management, Faculty of Ecology, Ulyanovsk State University, Ulyanovsk, Russia
| | - Yury Saenko
- Laboratory of Molecular and Cell Biology, S.P. Kapitsa Research Institute of Technology, Ulyanovsk State University, Ulyanovsk, Russian
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16
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Read GH, Bailleul J, Vlashi E, Kesarwala AH. Metabolic response to radiation therapy in cancer. Mol Carcinog 2022; 61:200-224. [PMID: 34961986 PMCID: PMC10187995 DOI: 10.1002/mc.23379] [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: 08/11/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 11/11/2022]
Abstract
Tumor metabolism has emerged as a hallmark of cancer and is involved in carcinogenesis and tumor growth. Reprogramming of tumor metabolism is necessary for cancer cells to sustain high proliferation rates and enhanced demands for nutrients. Recent studies suggest that metabolic plasticity in cancer cells can decrease the efficacy of anticancer therapies by enhancing antioxidant defenses and DNA repair mechanisms. Studying radiation-induced metabolic changes will lead to a better understanding of radiation response mechanisms as well as the identification of new therapeutic targets, but there are few robust studies characterizing the metabolic changes induced by radiation therapy in cancer. In this review, we will highlight studies that provide information on the metabolic changes induced by radiation and oxidative stress in cancer cells and the associated underlying mechanisms.
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Affiliation(s)
- Graham H. Read
- Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Justine Bailleul
- Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Erina Vlashi
- Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, California
| | - Aparna H. Kesarwala
- Department of Radiation Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia
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17
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Batnasan E, Koivukoski S, Kärkkäinen M, Latonen L. Nuclear Organization in Response to Stress: A Special Focus on Nucleoli. Results Probl Cell Differ 2022; 70:469-494. [PMID: 36348119 DOI: 10.1007/978-3-031-06573-6_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In this chapter, we discuss the nuclear organization and how it responds to different types of stress. A key component in these responses is molecular traffic between the different sub-nucleolar compartments, such as nucleoplasm, chromatin, nucleoli, and various speckle and body compartments. This allows specific repair and response activities in locations where they normally are not active and serve to halt sensitive functions until the stress insult passes and inflicted damage has been repaired. We focus on mammalian cells and their nuclear organization, especially describing the central role of the nucleolus in nuclear stress responses. We describe events after multiple stress types, including DNA damage, various drugs, and toxic compounds, and discuss the involvement of macromolecular traffic between dynamic, phase-separated nuclear organelles and foci. We delineate the key proteins and non-coding RNA in the formation of stress-responsive, non-membranous nuclear organelles, many of which are relevant to the formation of and utilization in cancer treatment.
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Affiliation(s)
- Enkhzaya Batnasan
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Sonja Koivukoski
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Minttu Kärkkäinen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Leena Latonen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland.
- Foundation for the Finnish Cancer Institute, Helsinki, Finland.
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18
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Ginsawaeng O, Heise C, Sangwan R, Karcher D, Hernández-Sánchez IE, Sampathkumar A, Zuther E. Subcellular Localization of Seed-Expressed LEA_4 Proteins Reveals Liquid-Liquid Phase Separation for LEA9 and for LEA48 Homo- and LEA42-LEA48 Heterodimers. Biomolecules 2021; 11:biom11121770. [PMID: 34944414 PMCID: PMC8698616 DOI: 10.3390/biom11121770] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/05/2021] [Accepted: 11/20/2021] [Indexed: 12/27/2022] Open
Abstract
LEA proteins are involved in plant stress tolerance. In Arabidopsis, the LEA_4 Pfam group is the biggest group with the majority of its members being expressed in dry seeds. To assess subcellular localization in vivo, we investigated 11 seed-expressed LEA_4 proteins in embryos dissected from dry seeds expressing LEA_4 fusion proteins under its native promoters with the Venus fluorescent protein (proLEA_4::LEA_4:Venus). LEA_4 proteins were shown to be localized in the endoplasmic reticulum, nucleus, mitochondria, and plastids. LEA9, in addition to the nucleus, was also found in cytoplasmic condensates in dry seeds dependent on cellular hydration level. Most investigated LEA_4 proteins were detected in 4-d-old seedlings. In addition, we assessed bioinformatic tools for predicting subcellular localization and promoter motifs of 11 seed-expressed LEA_4 proteins. Ratiometric bimolecular fluorescence complementation assays showed that LEA7, LEA29, and LEA48 form homodimers while heterodimers were formed between LEA7-LEA29 and LEA42-LEA48 in tobacco leaves. Interestingly, LEA48 homodimers and LEA42-LEA48 heterodimers formed droplets structures with liquid-like behavior. These structures, along with LEA9 cytoplasmic condensates, may have been formed through liquid-liquid phase separation. These findings suggest possible important roles of LLPS for LEA protein functions.
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19
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Tchurikov NA, Kravatsky YV. The Role of rDNA Clusters in Global Epigenetic Gene Regulation. Front Genet 2021; 12:730633. [PMID: 34531902 PMCID: PMC8438155 DOI: 10.3389/fgene.2021.730633] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/02/2021] [Indexed: 12/26/2022] Open
Abstract
The regulation of gene expression has been studied for decades, but the underlying mechanisms are still not fully understood. As well as local and distant regulation, there are specific mechanisms of regulation during development and physiological modulation of gene activity in differentiated cells. Current research strongly supports a role for the 3D chromosomal structure in the regulation of gene expression. However, it is not known whether the genome structure reflects the formation of active or repressed chromosomal domains or if these structures play a primary role in the regulation of gene expression. During early development, heterochromatinization of ribosomal DNA (rDNA) is coupled with silencing or activation of the expression of different sets of genes. Although the mechanisms behind this type of regulation are not known, rDNA clusters shape frequent inter-chromosomal contacts with a large group of genes controlling development. This review aims to shed light on the involvement of clusters of ribosomal genes in the global regulation of gene expression. We also discuss the possible role of RNA-mediated and phase-separation mechanisms in the global regulation of gene expression by nucleoli.
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Affiliation(s)
- Nickolai A Tchurikov
- Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Moscow, Russia
| | - Yuri V Kravatsky
- Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Moscow, Russia
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20
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Thoms HC, Stark LA. The NF-κB Nucleolar Stress Response Pathway. Biomedicines 2021; 9:biomedicines9091082. [PMID: 34572268 PMCID: PMC8471347 DOI: 10.3390/biomedicines9091082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/09/2021] [Accepted: 08/20/2021] [Indexed: 12/20/2022] Open
Abstract
The nuclear organelle, the nucleolus, plays a critical role in stress response and the regulation of cellular homeostasis. P53 as a downstream effector of nucleolar stress is well defined. However, new data suggests that NF-κB also acts downstream of nucleolar stress to regulate cell growth and death. In this review, we will provide insight into the NF-κB nucleolar stress response pathway. We will discuss apoptosis mediated by nucleolar sequestration of RelA and new data demonstrating a role for p62 (sequestosome (SQSTM1)) in this process. We will also discuss activation of NF-κB signalling by degradation of the RNA polymerase I (PolI) complex component, transcription initiation factor-IA (TIF-IA (RRN3)), and contexts where TIF-IA-NF-κB signalling may be important. Finally, we will discuss how this pathway is targeted by aspirin to mediate apoptosis of colon cancer cells.
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21
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Yoneda M, Nakagawa T, Hattori N, Ito T. The nucleolus from a liquid droplet perspective. J Biochem 2021; 170:153-162. [PMID: 34358306 DOI: 10.1093/jb/mvab090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/27/2021] [Indexed: 11/14/2022] Open
Abstract
The nucleolus is a membrane-less organelle sequestered from the nucleus by liquid droplet formation through a liquid-liquid phase separation (LLPS). It plays important roles in cell homeostasis through its internal thermodynamic changes. Reversible nucleolar transitions between coalescence and dispersion are dependent on the concentrations, conformations, and interactions of its molecular liquid droplet-forming components, including DNA, RNA, and protein. The liquid droplet-like properties of the nucleolus enable its diverse dynamic roles. The liquid droplet formation mechanism, by which the nucleolus is sequestered from the nucleoplasm despite the absence of a membrane, explains a number of complex nucleolar functions.
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Affiliation(s)
- Mitsuhiro Yoneda
- Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki, 852-8523, JAPAN.,Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8523, JAPAN
| | - Takeya Nakagawa
- Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki, 852-8523, JAPAN.,Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8523, JAPAN
| | - Naoko Hattori
- Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki, 852-8523, JAPAN.,Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8523, JAPAN
| | - Takashi Ito
- Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki, 852-8523, JAPAN.,Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8523, JAPAN
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22
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Xuan J, Gitareja K, Brajanovski N, Sanij E. Harnessing the Nucleolar DNA Damage Response in Cancer Therapy. Genes (Basel) 2021; 12:genes12081156. [PMID: 34440328 PMCID: PMC8393943 DOI: 10.3390/genes12081156] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/20/2021] [Accepted: 07/26/2021] [Indexed: 12/19/2022] Open
Abstract
The nucleoli are subdomains of the nucleus that form around actively transcribed ribosomal RNA (rRNA) genes. They serve as the site of rRNA synthesis and processing, and ribosome assembly. There are 400-600 copies of rRNA genes (rDNA) in human cells and their highly repetitive and transcribed nature poses a challenge for DNA repair and replication machineries. It is only in the last 7 years that the DNA damage response and processes of DNA repair at the rDNA repeats have been recognized to be unique and distinct from the classic response to DNA damage in the nucleoplasm. In the last decade, the nucleolus has also emerged as a central hub for coordinating responses to stress via sequestering tumor suppressors, DNA repair and cell cycle factors until they are required for their functional role in the nucleoplasm. In this review, we focus on features of the rDNA repeats that make them highly vulnerable to DNA damage and the mechanisms by which rDNA damage is repaired. We highlight the molecular consequences of rDNA damage including activation of the nucleolar DNA damage response, which is emerging as a unique response that can be exploited in anti-cancer therapy. In this review, we focus on CX-5461, a novel inhibitor of Pol I transcription that induces the nucleolar DNA damage response and is showing increasing promise in clinical investigations.
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Affiliation(s)
- Jiachen Xuan
- Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.X.); (K.G.); (N.B.)
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Kezia Gitareja
- Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.X.); (K.G.); (N.B.)
| | - Natalie Brajanovski
- Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.X.); (K.G.); (N.B.)
| | - Elaine Sanij
- Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.X.); (K.G.); (N.B.)
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Clinical Pathology, University of Melbourne, Melbourne, VIC 3010, Australia
- St Vincent’s Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Department of Medicine -St Vincent’s Hospital, University of Melbourne, Melbourne, VIC 3010, Australia
- Correspondence: ; Tel.: +61-3-8559-5279
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23
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Abbasi S, Parmar G, Kelly RD, Balasuriya N, Schild-Poulter C. The Ku complex: recent advances and emerging roles outside of non-homologous end-joining. Cell Mol Life Sci 2021; 78:4589-4613. [PMID: 33855626 PMCID: PMC11071882 DOI: 10.1007/s00018-021-03801-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/29/2021] [Accepted: 02/24/2021] [Indexed: 12/15/2022]
Abstract
Since its discovery in 1981, the Ku complex has been extensively studied under multiple cellular contexts, with most work focusing on Ku in terms of its essential role in non-homologous end-joining (NHEJ). In this process, Ku is well-known as the DNA-binding subunit for DNA-PK, which is central to the NHEJ repair process. However, in addition to the extensive study of Ku's role in DNA repair, Ku has also been implicated in various other cellular processes including transcription, the DNA damage response, DNA replication, telomere maintenance, and has since been studied in multiple contexts, growing into a multidisciplinary point of research across various fields. Some advances have been driven by clarification of Ku's structure, including the original Ku crystal structure and the more recent Ku-DNA-PKcs crystallography, cryogenic electron microscopy (cryoEM) studies, and the identification of various post-translational modifications. Here, we focus on the advances made in understanding the Ku heterodimer outside of non-homologous end-joining, and across a variety of model organisms. We explore unique structural and functional aspects, detail Ku expression, conservation, and essentiality in different species, discuss the evidence for its involvement in a diverse range of cellular functions, highlight Ku protein interactions and recent work concerning Ku-binding motifs, and finally, we summarize the clinical Ku-related research to date.
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Affiliation(s)
- Sanna Abbasi
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Gursimran Parmar
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Rachel D Kelly
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Nileeka Balasuriya
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Caroline Schild-Poulter
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada.
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24
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Ogawa LM, Buhagiar AF, Abriola L, Leland BA, Surovtseva YV, Baserga SJ. Increased numbers of nucleoli in a genome-wide RNAi screen reveal proteins that link the cell cycle to RNA polymerase I transcription. Mol Biol Cell 2021; 32:956-973. [PMID: 33689394 PMCID: PMC8108525 DOI: 10.1091/mbc.e20-10-0670] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Nucleoli are dynamic nuclear condensates in eukaryotic cells that originate through ribosome biogenesis at loci that harbor the ribosomal DNA. These loci are known as nucleolar organizer regions (NORs), and there are 10 in a human diploid genome. While there are 10 NORs, however, the number of nucleoli observed in cells is variable. Furthermore, changes in number are associated with disease, with increased numbers and size common in aggressive cancers. In the near-diploid human breast epithelial cell line, MCF10A, the most frequently observed number of nucleoli is two to three per cell. Here, to identify novel regulators of ribosome biogenesis we used high-throughput quantitative imaging of MCF10A cells to identify proteins that, when depleted, increase the percentage of nuclei with ≥5 nucleoli. Unexpectedly, this unique screening approach led to identification of proteins associated with the cell cycle. Functional analysis on a subset of hits further revealed not only proteins required for progression through the S and G2/M phase, but also proteins required explicitly for the regulation of RNA polymerase I transcription and protein synthesis. Thus, results from this screen for increased nucleolar number highlight the significance of the nucleolus in human cell cycle regulation, linking RNA polymerase I transcription to cell cycle progression.
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Affiliation(s)
- Lisa M Ogawa
- Department of Molecular Biophysics & Biochemistry, Yale University School of Medicine, New Haven, CT 06520
| | - Amber F Buhagiar
- Department of Molecular Biophysics & Biochemistry, Yale University School of Medicine, New Haven, CT 06520
| | - Laura Abriola
- Yale Center for Molecular Discovery, Yale University, West Haven, CT 06516
| | - Bryan A Leland
- Yale Center for Molecular Discovery, Yale University, West Haven, CT 06516
| | - Yulia V Surovtseva
- Yale Center for Molecular Discovery, Yale University, West Haven, CT 06516
| | - Susan J Baserga
- Department of Molecular Biophysics & Biochemistry, Yale University School of Medicine, New Haven, CT 06520.,Department of Genetics, Yale University School of Medicine, New Haven, CT 06520.,Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520
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25
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Weeks SE, Kammerud SC, Metge BJ, AlSheikh HA, Schneider DA, Chen D, Wei S, Mobley JA, Ojesina AI, Shevde LA, Samant RS. Inhibiting β-catenin disables nucleolar functions in triple-negative breast cancer. Cell Death Dis 2021; 12:242. [PMID: 33664239 PMCID: PMC7933177 DOI: 10.1038/s41419-021-03531-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 02/04/2021] [Accepted: 02/15/2021] [Indexed: 01/31/2023]
Abstract
Triple-negative breast cancer (TNBC) patients with upregulated Wnt/β-catenin signaling often have poor clinical prognoses. During pathological examinations of breast cancer sections stained for β-catenin, we made the serendipitous observation that relative to non-TNBC, specimens from TNBC patients have a greater abundance of nucleoli. There was a remarkable direct relationship between nuclear β-catenin and greater numbers of nucleoli in TNBC tissues. These surprising observations spurred our investigations to decipher the differential functional relevance of the nucleolus in TNBC versus non-TNBC cells. Comparative nucleolar proteomics revealed that the majority of the nucleolar proteins in TNBC cells were potential targets of β-catenin signaling. Next, we undertook an analysis of the nucleolar proteome in TNBC cells in response to β-catenin inhibition. This effort revealed that a vital component of pre-rRNA processing, LAS1 like ribosome biogenesis factor (LAS1L) was significantly decreased in the nucleoli of β-catenin inhibited TNBC cells. Here we demonstrate that LAS1L protein expression is significantly elevated in TNBC patients, and it functionally is important for mammary tumor growth in xenograft models and enables invasive attributes. Our observations highlight a novel function for β-catenin in orchestrating nucleolar activity in TNBCs.
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Affiliation(s)
- Shannon E Weeks
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sarah C Kammerud
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brandon J Metge
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Heba A AlSheikh
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David A Schneider
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Dongquan Chen
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Shi Wei
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - James A Mobley
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Akinyemi I Ojesina
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lalita A Shevde
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rajeev S Samant
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA.
- Birmingham VA Medical Center, Birmingham, AL, USA.
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26
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González-Prieto R, Eifler-Olivi K, Claessens LA, Willemstein E, Xiao Z, Talavera Ormeno CMP, Ovaa H, Ulrich HD, Vertegaal ACO. Global non-covalent SUMO interaction networks reveal SUMO-dependent stabilization of the non-homologous end joining complex. Cell Rep 2021; 34:108691. [PMID: 33503430 DOI: 10.1016/j.celrep.2021.108691] [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: 07/23/2020] [Revised: 12/11/2020] [Accepted: 01/05/2021] [Indexed: 12/17/2022] Open
Abstract
In contrast to our extensive knowledge on covalent small ubiquitin-like modifier (SUMO) target proteins, we are limited in our understanding of non-covalent SUMO-binding proteins. We identify interactors of different SUMO isoforms-monomeric SUMO1, monomeric SUMO2, or linear trimeric SUMO2 chains-using a mass spectrometry-based proteomics approach. We identify 379 proteins that bind to different SUMO isoforms, mainly in a preferential manner. Interestingly, XRCC4 is the only DNA repair protein in our screen with a preference for SUMO2 trimers over mono-SUMO2, as well as the only protein in our screen that belongs to the non-homologous end joining (NHEJ) DNA double-strand break repair pathway. A SUMO interaction motif (SIM) in XRCC4 regulates its recruitment to sites of DNA damage and phosphorylation of S320 by DNA-PKcs. Our data highlight the importance of non-covalent and covalent sumoylation for DNA double-strand break repair via the NHEJ pathway and provide a resource of SUMO isoform interactors.
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Affiliation(s)
- Román González-Prieto
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands.
| | - Karolin Eifler-Olivi
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands; Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Laura A Claessens
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Edwin Willemstein
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Zhenyu Xiao
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Cami M P Talavera Ormeno
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands; Oncode Institute, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Huib Ovaa
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands; Oncode Institute, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Helle D Ulrich
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Alfred C O Vertegaal
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands.
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27
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Korsholm LM, Gál Z, Nieto B, Quevedo O, Boukoura S, Lund CC, Larsen DH. Recent advances in the nucleolar responses to DNA double-strand breaks. Nucleic Acids Res 2020; 48:9449-9461. [PMID: 32857853 PMCID: PMC7515731 DOI: 10.1093/nar/gkaa713] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/13/2020] [Accepted: 08/26/2020] [Indexed: 12/15/2022] Open
Abstract
DNA damage poses a serious threat to human health and cells therefore continuously monitor and repair DNA lesions across the genome. Ribosomal DNA is a genomic domain that represents a particular challenge due to repetitive sequences, high transcriptional activity and its localization in the nucleolus, where the accessibility of DNA repair factors is limited. Recent discoveries have significantly extended our understanding of how cells respond to DNA double-strand breaks (DSBs) in the nucleolus, and new kinases and multiple down-stream targets have been identified. Restructuring of the nucleolus can occur as a consequence of DSBs and new data point to an active regulation of this process, challenging previous views. Furthermore, new insights into coordination of cell cycle phases and ribosomal DNA repair argue against existing concepts. In addition, the importance of nucleolar-DNA damage response (n-DDR) mechanisms for maintenance of genome stability and the potential of such factors as anti-cancer targets is becoming apparent. This review will provide a detailed discussion of recent findings and their implications for our understanding of the n-DDR. The n-DDR shares features with the DNA damage response (DDR) elsewhere in the genome but is also emerging as an independent response unique to ribosomal DNA and the nucleolus.
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Affiliation(s)
| | | | - Blanca Nieto
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Oliver Quevedo
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Stavroula Boukoura
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Casper Carstens Lund
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
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28
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Zhang W, Cheng W, Parlato R, Guo X, Cui X, Dai C, Xu L, Zhu J, Zhu M, Luo K, Zhang W, Dong B, Wang J, Jiang F. Nucleolar stress induces a senescence-like phenotype in smooth muscle cells and promotes development of vascular degeneration. Aging (Albany NY) 2020; 12:22174-22198. [PMID: 33146634 PMCID: PMC7695416 DOI: 10.18632/aging.104094] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/31/2020] [Indexed: 12/24/2022]
Abstract
Senescence of smooth muscle cells (SMCs) has a crucial role in the pathogenesis of abdominal aortic aneurysm (AAA), a disease of vascular degeneration. Perturbation of cellular ribosomal DNA (rDNA) transcription triggers nucleolar stress response. Previously we demonstrated that induction of nucleolar stress in SMCs elicited cell cycle arrest via the ataxia-telangiectasia mutated (ATM)/ATM- and Rad3-related (ATR)-p53 axis. However, the specific roles of nucleolar stress in vascular degeneration remain unexplored. In the present study, we demonstrated for the first time that in both human and animal AAA tissues, there were non-coordinated changes in the expression of RNA polymerase I machinery components, including a downregulation of transcription initiation factor-IA (TIF-IA). Genetic deletion of TIF-IA in SMCs in mice (smTIF-IA-/-) caused spontaneous aneurysm-like lesions in the aorta. In vitro, induction of nucleolar stress triggered a non-canonical DNA damage response, leading to p53 phosphorylation and a senescence-like phenotype in SMCs. In human AAA tissues, there was increased nucleolar stress in medial cells, accompanied by localized DNA damage response within the nucleolar compartment. Our data suggest that perturbed rDNA transcription and induction of nucleolar stress contribute to the pathogenesis of AAA. Moreover, smTIF-IA-/- mice may be a novel animal model for studying spontaneous AAA-like vascular degenerations.
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Affiliation(s)
- Wenjing Zhang
- Department of Physiology and Pathophysiology, School of Basic Medicine, Cheeloo College of Medicine, Shandong University, Jinan, Shandong Province, China.,Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qilu Hospital of Shandong University, Jinan, China
| | - Wen Cheng
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, and The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital of Shandong University, Jinan, China
| | - Rosanna Parlato
- Institute of Applied Physiology, University of Ulm, Ulm, Germany.,Institute of Anatomy and Cell Biology, University of Heidelberg, Heidelberg, Germany
| | - Xiaosun Guo
- Department of Physiology and Pathophysiology, School of Basic Medicine, Cheeloo College of Medicine, Shandong University, Jinan, Shandong Province, China
| | - Xiaopei Cui
- Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qilu Hospital of Shandong University, Jinan, China
| | - Chaochao Dai
- Department of Physiology and Pathophysiology, School of Basic Medicine, Cheeloo College of Medicine, Shandong University, Jinan, Shandong Province, China.,Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qilu Hospital of Shandong University, Jinan, China
| | - Lei Xu
- Department of Vascular Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Jiankang Zhu
- Department of General Surgery, The First Affiliated Hospital of Shandong First Medical University, Jinan, China
| | - Min Zhu
- Department of Transplant Surgery, Qilu Hospital of Shandong University, Jinan, China
| | - Kun Luo
- Department of Vascular Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Wencheng Zhang
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, and The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital of Shandong University, Jinan, China
| | - Bo Dong
- Department of Cardiology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
| | - Jianli Wang
- Department of Physiology and Pathophysiology, School of Basic Medicine, Cheeloo College of Medicine, Shandong University, Jinan, Shandong Province, China.,Current address: Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, Jinan, China
| | - Fan Jiang
- Department of Physiology and Pathophysiology, School of Basic Medicine, Cheeloo College of Medicine, Shandong University, Jinan, Shandong Province, China.,Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qilu Hospital of Shandong University, Jinan, China
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29
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Abstract
The nucleolus is the most prominent nuclear body and serves a fundamentally important biological role as a site of ribonucleoprotein particle assembly, primarily dedicated to ribosome biogenesis. Despite being one of the first intracellular structures visualized historically, the biophysical rules governing its assembly and function are only starting to become clear. Recent studies have provided increasing support for the concept that the nucleolus represents a multilayered biomolecular condensate, whose formation by liquid-liquid phase separation (LLPS) facilitates the initial steps of ribosome biogenesis and other functions. Here, we review these biophysical insights in the context of the molecular and cell biology of the nucleolus. We discuss how nucleolar function is linked to its organization as a multiphase condensate and how dysregulation of this organization could provide insights into still poorly understood aspects of nucleolus-associated diseases, including cancer, ribosomopathies and neurodegeneration as well as ageing. We suggest that the LLPS model provides the starting point for a unifying quantitative framework for the assembly, structural maintenance and function of the nucleolus, with implications for gene regulation and ribonucleoprotein particle assembly throughout the nucleus. The LLPS concept is also likely useful in designing new therapeutic strategies to target nucleolar dysfunction.
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30
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Vydzhak O, Luke B, Schindler N. Non-coding RNAs at the Eukaryotic rDNA Locus: RNA-DNA Hybrids and Beyond. J Mol Biol 2020; 432:4287-4304. [PMID: 32446803 DOI: 10.1016/j.jmb.2020.05.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 05/14/2020] [Accepted: 05/15/2020] [Indexed: 12/12/2022]
Abstract
The human ribosomal DNA (rDNA) locus encodes a variety of long non-coding RNAs (lncRNAs). Among them, the canonical ribosomal RNAs that are the catalytic components of the ribosomes, as well as regulatory lncRNAs including promoter-associated RNAs (pRNA), stress-induced promoter and pre-rRNA antisense RNAs (PAPAS), and different intergenic spacer derived lncRNA species (IGSRNA). In addition, externally encoded lncRNAs are imported into the nucleolus, which orchestrate the complex regulation of the nucleolar state in normal and stress conditions via a plethora of molecular mechanisms. This review focuses on the triplex and R-loop formation aspects of lncRNAs at the rDNA locus in yeast and human cells. We discuss the protein players that regulate R-loops at rDNA and how their misregulation contributes to DNA damage and disease. Furthermore, we speculate how DNA lesions such as rNMPs or 8-oxo-dG might affect RNA-DNA hybrid formation. The transcription of lncRNA from rDNA has been observed in yeast, plants, flies, worms, mouse and human cells. This evolutionary conservation highlights the importance of lncRNAs in rDNA function and maintenance.
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Affiliation(s)
- Olga Vydzhak
- Institute of Molecular Biology (IMB), Johannes Gutenberg-University Mainz, Ackermannweg 4, 55128 Mainz, Germany
| | - Brian Luke
- Institute of Molecular Biology (IMB), Johannes Gutenberg-University Mainz, Ackermannweg 4, 55128 Mainz, Germany; Institute of Developmental Biology and Neurobiology (IDN), Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Natalie Schindler
- Institute of Developmental Biology and Neurobiology (IDN), Johannes Gutenberg-University Mainz, 55128 Mainz, Germany.
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31
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Kohata K, Miyoshi D. RNA phase separation-mediated direction of molecular trafficking under conditions of molecular crowding. Biophys Rev 2020; 12:669-676. [PMID: 32415614 DOI: 10.1007/s12551-020-00696-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/28/2020] [Indexed: 12/14/2022] Open
Abstract
Living cells are highly crowded with large and small biomolecules. The total concentration of biomolecules can reach 400 mg/ml, and 40% of the cell volume is occupied by biomolecules. Droplet formation in cells via liquid-liquid phase separation may play a role in controlling biochemical reactions in this complex molecular environment. Liquid-liquid phase separation generally involves nucleic acids and proteins as anionic and cationic components, respectively. Significant characteristics of droplets, which make them different from protein aggregation or fibril formation, are reversibility of formation and responsiveness to the molecular environment. In this review, we quantitatively describe the molecular environment inside cells and droplets that participate in controlling central dogma reactions. Finally, we discuss the importance of droplets under conditions of molecular crowding within living cells.
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Affiliation(s)
- Kazuki Kohata
- Faculty of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Daisuke Miyoshi
- Faculty of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan.
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32
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Siebenwirth C, Greubel C, Drexler GA, Reindl J, Walsh DWM, Schwarz B, Sammer M, Baur I, Pospiech H, Schmid TE, Dollinger G, Friedl AA. Local inhibition of rRNA transcription without nucleolar segregation after targeted ion irradiation of the nucleolus. J Cell Sci 2019; 132:jcs.232181. [PMID: 31492757 PMCID: PMC6803363 DOI: 10.1242/jcs.232181] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 08/29/2019] [Indexed: 12/18/2022] Open
Abstract
Nucleoli have attracted interest for their role as cellular stress sensors and as potential targets for cancer treatment. The effect of DNA double-strand breaks (DSBs) in nucleoli on rRNA transcription and nucleolar organisation appears to depend on the agent used to introduce DSBs, DSB frequency and the presence (or not) of DSBs outside the nucleoli. To address the controversy, we targeted nucleoli with carbon ions at the ion microbeam SNAKE. Localized ion irradiation with 1-100 carbon ions per point (about 0.3-30 Gy per nucleus) did not lead to overall reduced ribonucleotide incorporation in the targeted nucleolus or other nucleoli of the same cell. However, both 5-ethynyluridine incorporation and Parp1 protein levels were locally decreased at the damaged nucleolar chromatin regions marked by γH2AX, suggesting localized inhibition of rRNA transcription. This locally restricted transcriptional inhibition was not accompanied by nucleolar segregation, a structural reorganisation observed after inhibition of rRNA transcription by treatment with actinomycin D or UV irradiation. The presented data indicate that even multiple complex DSBs do not lead to a pan-nucleolar response if they affect only a subnucleolar region.
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Affiliation(s)
- Christian Siebenwirth
- Bundeswehr Institute of Radiobiology, 80937 Munich, Germany .,Institute for Applied Physics and Metrology, Universität der Bundeswehr München, 85577 Neubiberg, Germany.,Department of Radiation Therapy and Radiooncology, Technical University of Munich, 81675 Munich, Germany
| | - Christoph Greubel
- Institute for Applied Physics and Metrology, Universität der Bundeswehr München, 85577 Neubiberg, Germany
| | - Guido A Drexler
- Department of Radiation Oncology, University Hospital, Ludwig Maximilians University of Munich, 81377 Munich, Germany
| | - Judith Reindl
- Institute for Applied Physics and Metrology, Universität der Bundeswehr München, 85577 Neubiberg, Germany
| | - Dietrich W M Walsh
- Institute for Applied Physics and Metrology, Universität der Bundeswehr München, 85577 Neubiberg, Germany
| | - Benjamin Schwarz
- Institute for Applied Physics and Metrology, Universität der Bundeswehr München, 85577 Neubiberg, Germany
| | - Matthias Sammer
- Institute for Applied Physics and Metrology, Universität der Bundeswehr München, 85577 Neubiberg, Germany
| | - Iris Baur
- Department of Radiation Oncology, University Hospital, Ludwig Maximilians University of Munich, 81377 Munich, Germany
| | - Helmut Pospiech
- Leibniz Institute for Age Research - Fritz Lipmann Institute (FLI), 07745 Jena, Germany
| | - Thomas E Schmid
- Department of Radiation Therapy and Radiooncology, Technical University of Munich, 81675 Munich, Germany
| | - Günther Dollinger
- Institute for Applied Physics and Metrology, Universität der Bundeswehr München, 85577 Neubiberg, Germany
| | - Anna A Friedl
- Department of Radiation Oncology, University Hospital, Ludwig Maximilians University of Munich, 81377 Munich, Germany
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33
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Chen J, Stark LA. Insights into the Relationship between Nucleolar Stress and the NF-κB Pathway. Trends Genet 2019; 35:768-780. [PMID: 31434627 DOI: 10.1016/j.tig.2019.07.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/22/2019] [Accepted: 07/24/2019] [Indexed: 02/06/2023]
Abstract
The nuclear organelle the nucleolus and the transcription factor nuclear factor of κ-light-chain-enhancer of activated B cells (NF-κB) are both central to the control of cellular homeostasis, dysregulated in common diseases and implicated in the ageing process. Until recently, it was believed that they acted independently to regulate homeostasis in health and disease. However, there is an emerging body of evidence suggesting that nucleoli and NF-κB signalling converge at multiple levels. Here we will review current understanding of this crosstalk. We will discuss activation of the NF-κB pathway by nucleolar stress and induction of apoptosis by nucleolar sequestration of NF-κB/RelA. We will also discuss the role of TIF-IA, COMMD1, and nucleophosmin, which are key players in this crosstalk, and the therapeutic relevance, particularly with respect to the antitumour effects of aspirin.
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Affiliation(s)
- Jingyu Chen
- University of Edinburgh Cancer Research Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Road, Edinburgh, Scotland EH4 2XU, UK
| | - Lesley A Stark
- University of Edinburgh Cancer Research Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Road, Edinburgh, Scotland EH4 2XU, UK.
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34
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Chen YT, Chen JJ, Wang HT. Targeting RNA Polymerase I with Hernandonine Inhibits Ribosomal RNA Synthesis and Tumor Cell Growth. Mol Cancer Res 2019; 17:2294-2305. [PMID: 31409627 DOI: 10.1158/1541-7786.mcr-19-0402] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/08/2019] [Accepted: 08/08/2019] [Indexed: 11/16/2022]
Abstract
RNA polymerase I (RNA Pol. I) activity is consistently expanded in multiplying cells to continue the expanded interest for ribosome generation and protein synthesis, which are fundamental for cell development and division. Thus, selective inhibitors of RNA Pol. I may offer a general helpful intends to block cancer cell multiplication. Hernandonine, isolated from the root wood of Hernandia nymphaeifolia, causes rearrangement of nucleolar proteins consistent with segregation of the nucleolus, a hallmark of RNA Pol. I transcription stress. Furthermore, the compound destabilizes RPA194, the large catalytic protein of RNA Pol. I, in a proteasome-dependent manner and inhibits nascent rRNA synthesis and expression of the 45S rRNA precursor. Finally, hernandonine induces cellular apoptosis through a p53-dependent or p53-independent process in solid tumor cell lines. These outcomes feature the prevailing effect of RNA Pol. I transcription stress on apoptosis pathway initiation and present a synthetically novel and significant molecule that represses RNA Pol. I, making it a potential objective for malignancy treatment. IMPLICATIONS: Our findings position hernandonine as a potential, particular, and orally administered cancer treatment agent appropriate for use in investigational clinical trials.
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Affiliation(s)
- Yen-Ting Chen
- Department of Pharmacology, National Yang-Ming University, Taipei, Taiwan
| | - Jih-Jung Chen
- Faculty of Pharmacy, School of Pharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan.,Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
| | - Hsiang-Tsui Wang
- Department of Pharmacology, National Yang-Ming University, Taipei, Taiwan.
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35
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Nucleolar DNA Double-Strand Break Responses Underpinning rDNA Genomic Stability. Trends Genet 2019; 35:743-753. [PMID: 31353047 DOI: 10.1016/j.tig.2019.07.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/28/2019] [Accepted: 07/01/2019] [Indexed: 12/12/2022]
Abstract
Nucleoli, the sites of ribosome biogenesis, form around ribosomal gene (rDNA) arrays termed nucleolar organiser regions (NORs). These are the most transcriptionally active regions of the human genome and specialised responses have evolved to ensure their genomic stability. This review focuses on nucleolar responses to DNA double-strand breaks (DSBs) introduced into rDNA arrays using sequence-specific endonucleases, including CRISPR/Cas9. Repair of rDNA DSBs is predominantly carried out by the homology-directed repair (HDR) pathway that is facilitated by inhibition of transcription by RNA polymerase-I (Pol-I) and ensuing dramatic nucleolar reorganisation. Additionally, we review evidence that nucleoli can sense and respond to DSBs elsewhere in the genome.
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36
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PARP1 regulates DNA damage-induced nucleolar-nucleoplasmic shuttling of WRN and XRCC1 in a toxicant and protein-specific manner. Sci Rep 2019; 9:10075. [PMID: 31296950 PMCID: PMC6624289 DOI: 10.1038/s41598-019-46358-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 06/12/2019] [Indexed: 12/13/2022] Open
Abstract
The prime function of nucleoli is ribogenesis, however, several other, non-canonical functions have recently been identified, including a role in genotoxic stress response. Upon DNA damage, numerous proteins shuttle dynamically between the nucleolus and the nucleoplasm, yet the underlying molecular mechanisms are incompletely understood. Here, we demonstrate that PARP1 and PARylation contribute to genotoxic stress-induced nucleolar-nucleoplasmic shuttling of key genome maintenance factors in HeLa cells. Our work revealed that the RECQ helicase, WRN, translocates from nucleoli to the nucleoplasm upon treatment with the oxidizing agent H2O2, the alkylating agent 2-chloroethyl ethyl sulfide (CEES), and the topoisomerase inhibitor camptothecin (CPT). We show that after treatment with H2O2 and CEES, but not CPT, WRN translocation was dependent on PARP1 protein, yet independent of its enzymatic activity. In contrast, nucleolar-nucleoplasmic translocation of the base excision repair protein, XRCC1, was dependent on both PARP1 protein and its enzymatic activity. Furthermore, gossypol, which inhibits PARP1 activity by disruption of PARP1-protein interactions, abolishes nucleolar-nucleoplasmic shuttling of WRN, XRCC1 and PARP1, indicating the involvement of further upstream factors. In conclusion, this study highlights a prominent role of PARP1 in the DNA damage-induced nucleolar-nucleoplasmic shuttling of genome maintenance factors in HeLa cells in a toxicant and protein-specific manner.
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37
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Latonen L. Phase-to-Phase With Nucleoli - Stress Responses, Protein Aggregation and Novel Roles of RNA. Front Cell Neurosci 2019; 13:151. [PMID: 31080406 PMCID: PMC6497782 DOI: 10.3389/fncel.2019.00151] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 04/08/2019] [Indexed: 12/11/2022] Open
Abstract
Protein- and RNA-containing foci and aggregates are a hallmark of many age- and mutation-related neurodegenerative diseases. This article focuses on the role the nucleolus has as a hub in macromolecule regulation in the mammalian nucleus. The nucleolus has a well-established role in ribosome biogenesis and functions in several types of cellular stress responses. In addition to known reactions to DNA damaging and transcription inhibiting stresses, there is an emerging role of the nucleolus especially in responses to proteotoxic stress such as heat shock and inhibition of proteasome function. The nucleolus serves as an active regulatory site for detention of extranucleolar proteins. This takes place in nucleolar cavities and manifests in protein and RNA collections referred to as intranucleolar bodies (INBs), nucleolar aggresomes or amyloid bodies (A-bodies), depending on stress type, severity of accumulation, and material propensities of the macromolecular collections. These indicate a relevance of nucleolar function and regulation in neurodegeneration-related cellular events, but also provide surprising connections with cancer-related pathways. Yet, the molecular mechanisms governing these processes remain largely undefined. In this article, the nucleolus as the site of protein and RNA accumulation and as a possible protective organelle for nuclear proteins during stress is viewed. In addition, recent evidence of liquid-liquid phase separation (LLPS) and liquid-solid phase transition in the formation of nucleoli and its stress responses, respectively, are discussed, along with the increasingly indicated role and open questions for noncoding RNA species in these events.
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Affiliation(s)
- Leena Latonen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
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38
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Stixová L, Komůrková D, Svobodová Kovaříková A, Bártová E. UVA irradiation strengthened an interaction between UBF1/2 proteins and H4K20 di-/tri-methylation. Chromosome Res 2019; 27:41-55. [PMID: 30610403 DOI: 10.1007/s10577-018-9596-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/29/2018] [Accepted: 12/03/2018] [Indexed: 12/29/2022]
Abstract
Repair of ribosomal DNA (rDNA) is a very important nuclear process due to the most active transcription of ribosomal genes. Proper repair of rDNA is required for physiological biogenesis of ribosomes. Here, we analyzed the epigenetics of the DNA damage response in a nucleolar compartment, thus in the ribosomal genes studied in nonirradiated and UVA-irradiated mouse embryonic fibroblasts (MEFs). We found that the promoter of ribosomal genes is not abundant on H4K20me2, but it is densely occupied by H4K20me3. Ribosomal genes, regulated via UBF1/2 proteins, were characterized by an interaction between UBF1/2 and H4K20me2/me3. This interaction was strengthened by UVA irradiation that additionally causes a focal accumulation of H4K20me3 in the nucleolus. No interaction has been found between UBF1/2 and H3K9me3. Interestingly, UVA irradiation decreases the levels of H3K9me3 and H4K20me3 at 28S rDNA. Altogether, the UVA light affects the epigenetic status of ribosomal genes at 28S rDNA and strengthens an interaction between UBF1/2 proteins and H4K20me2/me3.
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Affiliation(s)
- Lenka Stixová
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, CZ-612 65, Brno, Czech Republic
| | - Denisa Komůrková
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, CZ-612 65, Brno, Czech Republic
| | - Alena Svobodová Kovaříková
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, CZ-612 65, Brno, Czech Republic
| | - Eva Bártová
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, CZ-612 65, Brno, Czech Republic.
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39
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Crosstalk between NF-κB and Nucleoli in the Regulation of Cellular Homeostasis. Cells 2018; 7:cells7100157. [PMID: 30301139 PMCID: PMC6210184 DOI: 10.3390/cells7100157] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 09/28/2018] [Accepted: 10/03/2018] [Indexed: 12/30/2022] Open
Abstract
Nucleoli are emerging as key sensors of cellular stress and regulators of the downstream consequences on proliferation, metabolism, senescence, and apoptosis. NF-κB signalling is activated in response to a similar plethora of stresses, which leads to modulation of cell growth and death programs. While nucleolar and NF-κB pathways are distinct, it is increasingly apparent that they converge at multiple levels. Exposure of cells to certain insults causes a specific type of nucleolar stress that is characterised by degradation of the PolI complex component, TIF-IA, and increased nucleolar size. Recent studies have shown that this atypical nucleolar stress lies upstream of cytosolic IκB degradation and NF-κB nuclear translocation. Under these stress conditions, the RelA component of NF-κB accumulates within functionally altered nucleoli to trigger a nucleophosmin dependent, apoptotic pathway. In this review, we will discuss these points of crosstalk and their relevance to anti-tumour mechanism of aspirin and small molecule CDK4 inhibitors. We will also briefly the discuss how crosstalk between nucleoli and NF-κB signalling may be more broadly relevant to the regulation of cellular homeostasis and how it may be exploited for therapeutic purpose.
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40
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Cuevas-Velazquez CL, Dinneny JR. Organization out of disorder: liquid-liquid phase separation in plants. CURRENT OPINION IN PLANT BIOLOGY 2018; 45:68-74. [PMID: 29859470 DOI: 10.1016/j.pbi.2018.05.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 04/17/2018] [Accepted: 05/09/2018] [Indexed: 05/06/2023]
Abstract
Membraneless compartments are formed from the dynamic physical association of proteins and RNAs through liquid-liquid phase separation, and have recently emerged as an exciting new mechanism to explain the dynamic organization of biochemical processes in the cell. In this review, we provide an overview of the current knowledge of the process of phase separation in plants and other eukaryotes. We discuss specific examples of liquid-like membraneless compartments found in green plants, their composition, and the intriguing prevalence of proteins with intrinsically disordered domains. Finally, we speculate on the function of disordered proteins in regulating the formation of membraneless compartments and how their conformational flexibility may be important for molecular memory and for sensing perturbations in the physicochemical environment of the cell, particularly important processes in sessile organisms.
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Affiliation(s)
| | - José R Dinneny
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA; Department of Biology, Stanford University, Stanford, CA 94305, USA.
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41
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Mechanistic insights in transcription-coupled nucleotide excision repair of ribosomal DNA. Proc Natl Acad Sci U S A 2018; 115:E6770-E6779. [PMID: 29967171 DOI: 10.1073/pnas.1716581115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nucleotide excision repair (NER) guarantees genome integrity against UV light-induced DNA damage. After UV irradiation, cells have to cope with a general transcriptional block. To ensure UV lesions repair specifically on transcribed genes, NER is coupled with transcription in an extremely organized pathway known as transcription-coupled repair. In highly metabolic cells, more than 60% of total cellular transcription results from RNA polymerase I activity. Repair of the mammalian transcribed ribosomal DNA has been scarcely studied. UV lesions severely block RNA polymerase I activity and the full transcription-coupled repair machinery corrects damage on actively transcribed ribosomal DNAs. After UV irradiation, RNA polymerase I is more bound to the ribosomal DNA and both are displaced to the nucleolar periphery. Importantly, the reentry of RNA polymerase I and the ribosomal DNA is dependent on the presence of UV lesions on DNA and independent of transcription restart.
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42
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Mitrea DM, Cika JA, Stanley CB, Nourse A, Onuchic PL, Banerjee PR, Phillips AH, Park CG, Deniz AA, Kriwacki RW. Self-interaction of NPM1 modulates multiple mechanisms of liquid-liquid phase separation. Nat Commun 2018; 9:842. [PMID: 29483575 PMCID: PMC5827731 DOI: 10.1038/s41467-018-03255-3] [Citation(s) in RCA: 247] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 01/31/2018] [Indexed: 12/20/2022] Open
Abstract
Nucleophosmin (NPM1) is an abundant, oligomeric protein in the granular component of the nucleolus with roles in ribosome biogenesis. Pentameric NPM1 undergoes liquid-liquid phase separation (LLPS) via heterotypic interactions with nucleolar components, including ribosomal RNA (rRNA) and proteins which display multivalent arginine-rich linear motifs (R-motifs), and is integral to the liquid-like nucleolar matrix. Here we show that NPM1 can also undergo LLPS via homotypic interactions between its polyampholytic intrinsically disordered regions, a mechanism that opposes LLPS via heterotypic interactions. Using a combination of biophysical techniques, including confocal microscopy, SAXS, analytical ultracentrifugation, and single-molecule fluorescence, we describe how conformational changes within NPM1 control valency and switching between the different LLPS mechanisms. We propose that this newly discovered interplay between multiple LLPS mechanisms may influence the direction of vectorial pre-ribosomal particle assembly within, and exit from the nucleolus as part of the ribosome biogenesis process.
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Affiliation(s)
- Diana M Mitrea
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Jaclyn A Cika
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Integrative Biomedical Sciences Program, University of Tennessee Health Sciences Center, Memphis, TN, 38163, USA
- Department of Biochemistry and Molecular Pharmacology, NYU Langone Medical Center, New York, NY, 10016, USA
| | - Christopher B Stanley
- Biology and Biomedical Sciences Group, Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Amanda Nourse
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Molecular Interaction Analysis Shared Resource, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Paulo L Onuchic
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Priya R Banerjee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
- Department of Physics, University of Buffalo, Buffalo, NY, 14260, USA
| | - Aaron H Phillips
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Cheon-Gil Park
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Ashok A Deniz
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Richard W Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center, Memphis, TN, 38163, USA.
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43
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Chen H, Han L, Tsai H, Wang Z, Wu Y, Duo Y, Cao W, Chen L, Tan Z, Xu N, Huang X, Zhuang J, Huang L. PICT-1 is a key nucleolar sensor in DNA damage response signaling that regulates apoptosis through the RPL11-MDM2-p53 pathway. Oncotarget 2018; 7:83241-83257. [PMID: 27829214 PMCID: PMC5347766 DOI: 10.18632/oncotarget.13082] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 10/19/2016] [Indexed: 12/12/2022] Open
Abstract
PICT-1 is an essential ribosome biogenesis factor whose loss induces p53 accumulation and apoptosis. Here, we show that DNA damage changes PICT-1 localization and decreases PICT-1 protein levels via the proteasome pathway. Two important phosphatidylinositol 3-kinase-like kinases (PIKKs), ataxia-telangiectasia mutated (ATM) and the Ku70 subunit of DNA-dependent protein kinase (DNA-PK), co-localize and interact with PICT-1 in the nucleolus. Computational prediction of phosphorylation sites and detection using an anti-phospho-substrate antibody suggest that PICT-1 might be a substrate of PIKKs. PICT-1 S233 and T289 were identified as the key phosphorylation sites in this pathway, as mutating both to alanine abolished UVB-induced increase of PICT-1 phosporylation. Inhibition of PIKKs or ATM (with wortmannin and KU55933, respectively) prevented the agglomeration and degradation of PICT-1, suggesting that ATM is a key regulator of PICT-1. PICT-1(S233A, T289A) demonstrated marked resistance to DNA damage-induced agglomeration and loss of PICT-1. Phosphomimetic PICT-1 (S233D, T289D) showed a different nuclear distribution and was more rapidly degraded after DNA damage than wild-type PICT-1. Furthermore, both phosphorylation and degradation of PICT-1 released RPL11 from the nucleolus to the nucleoplasm, increased binding of RPL11 to MDM2, and promoted p53 accumulation and apoptosis in an ATM-dependent manner after DNA damage. These data indicate that PICT-1 is a major nucleolar sensor of the DNA damage repair response and an important upstream regulator of p53 via the RPL11-MDM2-p53 pathway.
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Affiliation(s)
- Hongbo Chen
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China.,Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Liqiao Han
- Department of Laboratory Science, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China.,The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
| | - Hsiangi Tsai
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhiwei Wang
- Department of Laboratory Medicine, The Fourth Affiliated Hospital of Guangzhou Medical University, Guangzhou 511447, China
| | - Yanping Wu
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yanhong Duo
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
| | - Wei Cao
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lijun Chen
- Technology Center of Guangxi Entry-Exit Inspection and Quarantine Bureau, Nanning 530021, China
| | - Zhirong Tan
- Department of Laboratory Science, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China
| | - Ning Xu
- Department of Laboratory Science, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China
| | - Xianzhang Huang
- Department of Laboratory Science, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China
| | - Junhua Zhuang
- Department of Laboratory Science, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China
| | - Laiqiang Huang
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
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44
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Farg MA, Konopka A, Soo KY, Ito D, Atkin JD. The DNA damage response (DDR) is induced by the C9orf72 repeat expansion in amyotrophic lateral sclerosis. Hum Mol Genet 2018; 26:2882-2896. [PMID: 28481984 DOI: 10.1093/hmg/ddx170] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 05/02/2017] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressing neurodegenerative disease affecting motor neurons. Hexanucleotide (GGGGCC) repeat expansions in a non-coding region of C9orf72 are the major cause of familial ALS and frontotemporal dementia (FTD) worldwide. The C9orf72 repeat expansion undergoes repeat-associated non-ATG (RAN) translation to produce five dipeptide repeat proteins (DRPs), including poly(GR) and poly(PR). Whilst it remains unclear how mutations in C9orf72 lead to neurodegeneration in ALS/FTD, dysfunction to the nucleolus and R loop formation are implicated as pathogenic mechanisms. These events can damage DNA and hence genome integrity. Cells activate the DNA damage response (DDR) with the aim of repairing this damage. However, if the damage cannot be repaired, apoptosis is triggered. In lumbar motor neurons from C9orf72-positive ALS patients, we demonstrate significant up-regulation of markers of the DDR compared to controls: phosphorylated histone 2AX (γ-H2AX), phosphorylated ataxia telangiectasia mutated (p-ATM), cleaved poly (ADP-Ribose) polymerase 1 (PARP-1) and tumour suppressor p53-binding protein (53BP1). Similarly, significant up-regulation of γ-H2AX and p-ATM was detected in neuronal cells expressing poly(GR)100 and poly(PR)100 compared to controls, revealing that DNA damage is triggered by the DRPs. Nucleophosmin (NPM1) is a histone chaperone induced during the DDR, which interacts with APE1 to enhance DNA repair. We also demonstrate that more NPM1 precipitates with APE1 in C9orf72 patients compared to controls. Furthermore, overexpression of NPM1 inhibits apoptosis in cells expressing poly(GR)100 and poly(PR)100. This study therefore demonstrates that DNA damage is activated by the C9orf72 repeat expansion in ALS.
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Affiliation(s)
- Manal A Farg
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Anna Konopka
- Department of Biomedical Sciences, Faculty of Medicine & Health Sciences, 2 Technology Place, Macquarie University, NSW 2109, Australia
| | - Kai Ying Soo
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Daisuke Ito
- Department of Neurology, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Julie D Atkin
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia.,Department of Biomedical Sciences, Faculty of Medicine & Health Sciences, 2 Technology Place, Macquarie University, NSW 2109, Australia
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45
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Analyzing the influence of kinase inhibitors on DNA repair by differential proteomics of chromatin-interacting proteins and nuclear phospho-proteins. Oncotarget 2017; 8:110983-110993. [PMID: 29340031 PMCID: PMC5762299 DOI: 10.18632/oncotarget.22424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 10/25/2017] [Indexed: 11/25/2022] Open
Abstract
The combination of radiotherapy and pharmacological inhibition of cellular signal transduction pathways offers promising strategies for enhanced cancer cell inactivation. However, the molecular effects of kinase inhibitors especially on DNA damage detection and repair after X-irradiation have to be understood to facilitate the development of efficient and personalized treatment regimens. Therefore, we applied differential proteomics for analyzing inhibitor-induced changes in either chromatin-bound or phosphorylated nuclear proteins. The effect of the multi kinase inhibitor sorafenib on DNA repair, chromatin binding and phosphorylation of nuclear proteins was analyzed in UT-SCC 42B head and neck cancer cells using metabolic labeling based differential proteomics (SILAC). Sorafenib significantly inhibited DNA repair but failed to significantly affect chromatin interactions of 90 quantified proteins. In contrast, analyzing nuclear phospho-proteins following sorafenib treatment, we detected quantitative changes in 9 out of 59 proteins, including DNA-repair proteins. In conclusion, the analysis of nuclear phospho-proteins by differential proteomics is an effective tool for determining the molecular effects of kinase inhibitors on X-irradiated cells. Analyzing chromatin binding might be less promising.
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46
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Milek M, Imami K, Mukherjee N, Bortoli FD, Zinnall U, Hazapis O, Trahan C, Oeffinger M, Heyd F, Ohler U, Selbach M, Landthaler M. DDX54 regulates transcriptome dynamics during DNA damage response. Genome Res 2017; 27:1344-1359. [PMID: 28596291 PMCID: PMC5538551 DOI: 10.1101/gr.218438.116] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 06/05/2017] [Indexed: 12/12/2022]
Abstract
The cellular response to genotoxic stress is mediated by a well-characterized network of DNA surveillance pathways. The contribution of post-transcriptional gene regulatory networks to the DNA damage response (DDR) has not been extensively studied. Here, we systematically identified RNA-binding proteins differentially interacting with polyadenylated transcripts upon exposure of human breast carcinoma cells to ionizing radiation (IR). Interestingly, more than 260 proteins, including many nucleolar proteins, showed increased binding to poly(A)+ RNA in IR-exposed cells. The functional analysis of DDX54, a candidate genotoxic stress responsive RNA helicase, revealed that this protein is an immediate-to-early DDR regulator required for the splicing efficacy of its target IR-induced pre-mRNAs. Upon IR exposure, DDX54 acts by increased interaction with a well-defined class of pre-mRNAs that harbor introns with weak acceptor splice sites, as well as by protein-protein contacts within components of U2 snRNP and spliceosomal B complex, resulting in lower intron retention and higher processing rates of its target transcripts. Because DDX54 promotes survival after exposure to IR, its expression and/or mutation rate may impact DDR-related pathologies. Our work indicates the relevance of many uncharacterized RBPs potentially involved in the DDR.
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Affiliation(s)
- Miha Milek
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin Institute for Medical Systems Biology, 13125 Berlin, Germany
| | - Koshi Imami
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin Institute for Medical Systems Biology, 13125 Berlin, Germany
| | - Neelanjan Mukherjee
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin Institute for Medical Systems Biology, 13125 Berlin, Germany
| | - Francesca De Bortoli
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, 14195 Berlin, Germany
| | - Ulrike Zinnall
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin Institute for Medical Systems Biology, 13125 Berlin, Germany
| | - Orsalia Hazapis
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin Institute for Medical Systems Biology, 13125 Berlin, Germany
| | - Christian Trahan
- Institut de Recherches Cliniques de Montréal, H2W 1R7 Montréal, Quebec, Canada
- Département de Biochimie, Faculté de Médecine, Université de Montréal, H3A 1A3 Montréal, Quebec, Canada
| | - Marlene Oeffinger
- Institut de Recherches Cliniques de Montréal, H2W 1R7 Montréal, Quebec, Canada
- Département de Biochimie, Faculté de Médecine, Université de Montréal, H3A 1A3 Montréal, Quebec, Canada
- Faculty of Medicine, Division of Experimental Medicine, McGill University, H3T 1J4 Montréal, Quebec, Canada
| | - Florian Heyd
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, 14195 Berlin, Germany
| | - Uwe Ohler
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin Institute for Medical Systems Biology, 13125 Berlin, Germany
- Institute of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
- Department of Computer Science, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Matthias Selbach
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin Institute for Medical Systems Biology, 13125 Berlin, Germany
- Charite-Universitätsmedizin Berlin, 10115 Berlin, Germany
| | - Markus Landthaler
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin Institute for Medical Systems Biology, 13125 Berlin, Germany
- IRI Life Sciences, Institute of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
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Tsekrekou M, Stratigi K, Chatzinikolaou G. The Nucleolus: In Genome Maintenance and Repair. Int J Mol Sci 2017; 18:ijms18071411. [PMID: 28671574 PMCID: PMC5535903 DOI: 10.3390/ijms18071411] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 06/22/2017] [Accepted: 06/27/2017] [Indexed: 11/16/2022] Open
Abstract
The nucleolus is the subnuclear membrane-less organelle where rRNA is transcribed and processed and ribosomal assembly occurs. During the last 20 years, however, the nucleolus has emerged as a multifunctional organelle, regulating processes that go well beyond its traditional role. Moreover, the unique organization of rDNA in tandem arrays and its unusually high transcription rates make it prone to unscheduled DNA recombination events and frequent RNA:DNA hybrids leading to DNA double strand breaks (DSBs). If not properly repaired, rDNA damage may contribute to premature disease onset and aging. Deregulation of ribosomal synthesis at any level from transcription and processing to ribosomal subunit assembly elicits a stress response and is also associated with disease onset. Here, we discuss how genome integrity is maintained within nucleoli and how such structures are functionally linked to nuclear DNA damage response and repair giving an emphasis on the newly emerging roles of the nucleolus in mammalian physiology and disease.
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Affiliation(s)
- Maria Tsekrekou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Nikolaou Plastira 100, 70013 Heraklion, Crete, Greece.
- Department of Biology, University of Crete, Vassilika Vouton, 71409 Heraklion, Crete, Greece.
| | - Kalliopi Stratigi
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Nikolaou Plastira 100, 70013 Heraklion, Crete, Greece.
- Department of Biology, University of Crete, Vassilika Vouton, 71409 Heraklion, Crete, Greece.
| | - Georgia Chatzinikolaou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Nikolaou Plastira 100, 70013 Heraklion, Crete, Greece.
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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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49
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Bekpen C, Künzel S, Xie C, Eaaswarkhanth M, Lin YL, Gokcumen O, Akdis CA, Tautz D. Segmental duplications and evolutionary acquisition of UV damage response in the SPATA31 gene family of primates and humans. BMC Genomics 2017; 18:222. [PMID: 28264649 PMCID: PMC5338094 DOI: 10.1186/s12864-017-3595-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 02/20/2017] [Indexed: 12/11/2022] Open
Abstract
Background Segmental duplications are an abundant source for novel gene functions and evolutionary adaptations. This mechanism of generating novelty was very active during the evolution of primates particularly in the human lineage. Here, we characterize the evolution and function of the SPATA31 gene family (former designation FAM75A), which was previously shown to be among the gene families with the strongest signal of positive selection in hominoids. The mouse homologue for this gene family is a single copy gene expressed during spermatogenesis. Results We show that in primates, the SPATA31 gene duplicated into SPATA31A and SPATA31C types and broadened the expression into many tissues. Each type became further segmentally duplicated in the line towards humans with the largest number of full-length copies found for SPATA31A in humans. Copy number estimates of SPATA31A based on digital PCR show an average of 7.5 with a range of 5–11 copies per diploid genome among human individuals. The primate SPATA31 genes also acquired new protein domains that suggest an involvement in UV response and DNA repair. We generated antibodies and show that the protein is re-localized from the nucleolus to the whole nucleus upon UV-irradiation suggesting a UV damage response. We used CRISPR/Cas mediated mutagenesis to knockout copies of the gene in human primary fibroblast cells. We find that cell lines with reduced functional copies as well as naturally occurring low copy number HFF cells show enhanced sensitivity towards UV-irradiation. Conclusion The acquisition of new SPATA31 protein functions and its broadening of expression may be related to the evolution of the diurnal life style in primates that required a higher UV tolerance. The increased segmental duplications in hominoids as well as its fast evolution suggest the acquisition of further specific functions particularly in humans. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3595-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cemalettin Bekpen
- Max-Planck Institute for Evolutionary Biology, August-Thienemann Strasse 2, 24306, Plön, Germany.
| | - Sven Künzel
- Max-Planck Institute for Evolutionary Biology, August-Thienemann Strasse 2, 24306, Plön, Germany
| | - Chen Xie
- Max-Planck Institute for Evolutionary Biology, August-Thienemann Strasse 2, 24306, Plön, Germany
| | - Muthukrishnan Eaaswarkhanth
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, 14260-1300, NY, USA.,Present address: Population Genomics and Genetic Epidemiology Unit, Dasman Diabetes Institute, P.O.Box 1180, Dasman, 15462, Kuwait
| | - Yen-Lung Lin
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, 14260-1300, NY, USA
| | - Omer Gokcumen
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, 14260-1300, NY, USA
| | - Cezmi A Akdis
- Swiss Institute of Allergy and Asthma Research (SIAF), Davos, CH-7270, Switzerland
| | - Diethard Tautz
- Max-Planck Institute for Evolutionary Biology, August-Thienemann Strasse 2, 24306, Plön, Germany.
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50
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Ogawa LM, Baserga SJ. Crosstalk between the nucleolus and the DNA damage response. MOLECULAR BIOSYSTEMS 2017; 13:443-455. [PMID: 28112326 PMCID: PMC5340083 DOI: 10.1039/c6mb00740f] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Nucleolar function and the cellular response to DNA damage have long been studied as distinct disciplines. New research and a new appreciation for proteins holding multiple functional roles, however, is beginning to change the way we think about the crosstalk among distinct cellular processes. Here, we focus on the crosstalk between the DNA damage response and the nucleolus, including a comprehensive review of the literature that reveals a role for conventional DNA repair proteins in ribosome biogenesis, and conversely, ribosome biogenesis proteins in DNA repair. Furthermore, with recent advances in nucleolar proteomics and a growing list of proteins that localize to the nucleolus, it is likely that we will continue to identify new DNA repair proteins with a nucleolar-specific role. Given the importance of ribosome biogenesis and DNA repair in essential cellular processes and the role that they play in diverse pathologies, continued elucidation of the overlap between these two disciplines will be essential to the advancement of both fields and to the development of novel therapeutics.
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Affiliation(s)
- L M Ogawa
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - S J Baserga
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA. and Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA and Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
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