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El Osmani N, Prévostel C, Picque Lasorsa L, El Harakeh M, Radwan Z, Mawlawi H, El Sabban M, Shirinian M, Dassouki Z. Vitamin C enhances co-localization of novel TET1 nuclear bodies with both Cajal and PML bodies in colorectal cancer cells. Epigenetics 2024; 19:2337142. [PMID: 38583183 PMCID: PMC11000620 DOI: 10.1080/15592294.2024.2337142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 03/26/2024] [Indexed: 04/09/2024] Open
Abstract
Deregulation of ten-eleven Translocation protein 1 (TET1) is commonly reported to induce imbalances in gene expression and subsequently to colorectal cancer development (CRC). On the other hand, vitamin C (VitC) improves the prognosis of colorectal cancer by reprogramming the cancer epigenome and limiting chemotherapeutic drug resistance events. In this study, we aimed to characterize TET1-specific subcellular compartments and evaluate the effect of VitC on TET1 compartmentalization in colonic tumour cells. We demonstrated that TET1 is concentrated in coarse nuclear bodies (NB) and 5-hydroxymethylcytosine (5hmC) in foci in colorectal cancer cells (HCT116, Caco-2, and HT-29). To our knowledge, this is the first report of a novel intracellular localization profile of TET1 and its demethylation marker, 5hmC, in CRC cells. Interestingly, we found that TET1-NBs frequently interacted with Cajal bodies, but not with promyelocytic leukaemia (PML) bodies. In addition, we report that VitC treatment of HCT116 cells induces 5hmC foci biogenesis and triggers 5hmC marks to form active complexes with nuclear body components, including both Cajal and PML proteins. Our data highlight novel NB-concentrating TET1 in CRC cells and demonstrate that VitC modulates TET1-NBs' interactions with other nuclear structures. These findings reveal novel TET1-dependent cellular functions and potentially provide new insights for CRC management.
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Affiliation(s)
- Nour El Osmani
- IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, France
- Université de Montpellier, Montpellier, France
- Laboratory of Applied Biotechnology (LBA3B), AZM Center for Research in Biotechnology and its Applications, Doctoral School for Sciences and Technology, Tripoli, Lebanon
| | - Corinne Prévostel
- IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, France
- Université de Montpellier, Montpellier, France
- INSERM, Montpellier, France
- ICM, Institut régional du Cancer de Montpellier, Montpellier, France
| | - Laurence Picque Lasorsa
- IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, France
- Université de Montpellier, Montpellier, France
- INSERM, Montpellier, France
- ICM, Institut régional du Cancer de Montpellier, Montpellier, France
| | - Mohammad El Harakeh
- Department of Anatomy, Cell Biology, and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Zeina Radwan
- Department of Anatomy, Cell Biology, and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Hiba Mawlawi
- Laboratory of Applied Biotechnology (LBA3B), AZM Center for Research in Biotechnology and its Applications, Doctoral School for Sciences and Technology, Tripoli, Lebanon
- Faculty of Public Health, Lebanese University, Tripoli, Lebanon
| | - Marwan El Sabban
- Department of Anatomy, Cell Biology, and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Margret Shirinian
- Department of Experiment Pathology, Immunology, and Microbiology, American University of Beirut, Faculty of Medicine, Beirut, Lebanon
| | - Zeina Dassouki
- Laboratory of Applied Biotechnology (LBA3B), AZM Center for Research in Biotechnology and its Applications, Doctoral School for Sciences and Technology, Tripoli, Lebanon
- Department of Medical Laboratory Sciences, University of Balamand, Faculty of Health Sciences, Tripoli, Lebanon
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2
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King MR, Ruff KM, Lin AZ, Pant A, Farag M, Lalmansingh JM, Wu T, Fossat MJ, Ouyang W, Lew MD, Lundberg E, Vahey MD, Pappu RV. Macromolecular condensation organizes nucleolar sub-phases to set up a pH gradient. Cell 2024; 187:1889-1906.e24. [PMID: 38503281 DOI: 10.1016/j.cell.2024.02.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 01/02/2024] [Accepted: 02/22/2024] [Indexed: 03/21/2024]
Abstract
Nucleoli are multicomponent condensates defined by coexisting sub-phases. We identified distinct intrinsically disordered regions (IDRs), including acidic (D/E) tracts and K-blocks interspersed by E-rich regions, as defining features of nucleolar proteins. We show that the localization preferences of nucleolar proteins are determined by their IDRs and the types of RNA or DNA binding domains they encompass. In vitro reconstitutions and studies in cells showed how condensation, which combines binding and complex coacervation of nucleolar components, contributes to nucleolar organization. D/E tracts of nucleolar proteins contribute to lowering the pH of co-condensates formed with nucleolar RNAs in vitro. In cells, this sets up a pH gradient between nucleoli and the nucleoplasm. By contrast, juxta-nucleolar bodies, which have different macromolecular compositions, featuring protein IDRs with very different charge profiles, have pH values that are equivalent to or higher than the nucleoplasm. Our findings show that distinct compositional specificities generate distinct physicochemical properties for condensates.
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Affiliation(s)
- Matthew R King
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Kiersten M Ruff
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Andrew Z Lin
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Avnika Pant
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Mina Farag
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jared M Lalmansingh
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Tingting Wu
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Department of Electrical and Systems Engineering, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Martin J Fossat
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Wei Ouyang
- Department of Bioengineering, Schools of Engineering and Medicine, Stanford University, Stanford, CA, USA; Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA; Science for Life Laboratory, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH-Royal Institute of Technology, Stockholm, Sweden
| | - Matthew D Lew
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Department of Electrical and Systems Engineering, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Emma Lundberg
- Department of Bioengineering, Schools of Engineering and Medicine, Stanford University, Stanford, CA, USA; Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA; Science for Life Laboratory, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH-Royal Institute of Technology, Stockholm, Sweden
| | - Michael D Vahey
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Rohit V Pappu
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA.
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Jing X, Wang P, Liu J, Xiang M, Song X, Wang C, Li P, Li H, Wu Z, Zhang C. A viral protein competitively bound to rice CIPK23 inhibits potassium absorption and facilitates virus systemic infection in rice. Plant Biotechnol J 2024. [PMID: 38578842 DOI: 10.1111/pbi.14350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 02/02/2024] [Accepted: 03/20/2024] [Indexed: 04/07/2024]
Abstract
Potassium (K+) plays a crucial role as a macronutrient in the growth and development of plants. Studies have definitely determined the vital roles of K+ in response to pathogen invasion. Our previous investigations revealed that rice plants infected with rice grassy stunt virus (RGSV) displayed a reduction in K+ content, but the mechanism by which RGSV infection subverts K+ uptake remains unknown. In this study, we found that overexpression of RGSV P1, a specific viral protein encoded by viral RNA1, results in enhanced sensitivity to low K+ stress and exhibits a significantly lower rate of K+ influx compared to wild-type rice plants. Further investigation revealed that RGSV P1 interacts with OsCIPK23, an upstream regulator of Shaker K+ channel OsAKT1. Moreover, we found that the P1 protein recruits the OsCIPK23 to the Cajal bodies (CBs). In vivo assays demonstrated that the P1 protein competitively binds to OsCIPK23 with both OsCBL1 and OsAKT1. In the nucleus, the P1 protein enhances the binding of OsCIPK23 to OsCoilin, a homologue of the signature protein of CBs in Arabidopsis, and facilitates their trafficking through these CB structures. Genetic analysis indicates that mutant in oscipk23 suppresses RGSV systemic infection. Conversely, osakt1 mutants exhibited increased sensitivity to RGSV infection. These findings suggest that RGSV P1 hinders the absorption of K+ in rice plants by recruiting the OsCIPK23 to the CB structures. This process potentially promotes virus systemic infection but comes at the expense of inhibiting OsAKT1 activity.
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Affiliation(s)
- Xinxin Jing
- The Engineering Research Center for Plant Health Protection Technology in Henan Province, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
- Fujian Province Key Laboratory of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Pengyue Wang
- The Engineering Research Center for Plant Health Protection Technology in Henan Province, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
- Fujian Province Key Laboratory of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jianjian Liu
- The Engineering Research Center for Plant Health Protection Technology in Henan Province, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
- Hubei Engineering Research Center for Pest Forewarning and Management, College of Agronomy, Yangtze University, Jingzhou, China
| | - Meirong Xiang
- The Engineering Research Center for Plant Health Protection Technology in Henan Province, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Xia Song
- Fujian Province Key Laboratory of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Chaonan Wang
- The Engineering Research Center for Plant Health Protection Technology in Henan Province, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Pengbai Li
- The Engineering Research Center for Plant Health Protection Technology in Henan Province, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Honglian Li
- The Engineering Research Center for Plant Health Protection Technology in Henan Province, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Zujian Wu
- Fujian Province Key Laboratory of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Chao Zhang
- The Engineering Research Center for Plant Health Protection Technology in Henan Province, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
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Fakim H, Vande Velde C. The implications of physiological biomolecular condensates in amyotrophic lateral sclerosis. Semin Cell Dev Biol 2024; 156:176-189. [PMID: 37268555 DOI: 10.1016/j.semcdb.2023.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/13/2023] [Accepted: 05/16/2023] [Indexed: 06/04/2023]
Abstract
In recent years, there has been an emphasis on the role of phase-separated biomolecular condensates, especially stress granules, in neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). This is largely due to several ALS-associated mutations occurring in genes involved in stress granule assembly and observations that pathological inclusions detected in ALS patient neurons contain stress granule proteins, including the ALS-linked proteins TDP-43 and FUS. However, protein components of stress granules are also found in numerous other phase-separated biomolecular condensates under physiological conditions which are inadequately discussed in the context of ALS. In this review, we look beyond stress granules and describe the roles of TDP-43 and FUS in physiological condensates occurring in the nucleus and neurites, such as the nucleolus, Cajal bodies, paraspeckles and neuronal RNA transport granules. We also discuss the consequences of ALS-linked mutations in TDP-43 and FUS on their ability to phase separate into these stress-independent biomolecular condensates and perform their respective functions. Importantly, biomolecular condensates sequester multiple overlapping protein and RNA components, and their dysregulation could contribute to the observed pleiotropic effects of both sporadic and familial ALS on RNA metabolism.
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Affiliation(s)
- Hana Fakim
- Department of Neurosciences, Université de Montréal, and CHUM Research Center, Montréal, QC, Canada
| | - Christine Vande Velde
- Department of Neurosciences, Université de Montréal, and CHUM Research Center, Montréal, QC, Canada.
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Milosevic E, Novkovic M, Cenni V, Bavelloni A, Kojic S, Jasnic J. Molecular characterization of ANKRD1 in rhabdomyosarcoma cell lines: expression, localization, and proteasomal degradation. Histochem Cell Biol 2024:10.1007/s00418-024-02272-2. [PMID: 38396247 DOI: 10.1007/s00418-024-02272-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/11/2024] [Indexed: 02/25/2024]
Abstract
Rhabdomyosarcoma (RMS) is the most common soft tissue malignancy in children and adolescents. Respecting the age of the patients and the tumor aggressiveness, investigation of the molecular mechanisms of RMS tumorigenesis is directed toward the identification of novel therapeutic targets. To contribute to a better understanding of the molecular pathology of RMS, we investigated ankyrin repeat domain 1 (ANKRD1), designated as a potential marker for differential diagnostics. In this study, we used three RMS cell lines (SJRH30, RD, and HS-729) to assess its expression profile, intracellular localization, and turnover. They express wild-type ANKRD1, as judged by the sequencing of the open reading frame. Each cell line expressed a different amount of ANKRD1 protein, although the transcript level was similar. According to western blot analysis, ANKRD1 protein was expressed at detectable levels in the SJRH30 and RD cells (SJRH30 > RD), but not in the HS-729, even after immunoprecipitation. Immunocytochemistry revealed nuclear and cytoplasmic localization of ANKRD1 in all examined cell lines. Moreover, the punctate pattern of ANKRD1 staining in the nuclei of RD and HS-729 cells overlapped with coilin, indicating its association with Cajal bodies. We have shown that RMS cells are not able to overexpress ANKRD1 protein, which can be attributed to its proteasomal degradation. The unsuccessful attempt to overexpress ANKRD1 in RMS cells indicates the possibility that its overexpression may have detrimental effects for RMS cells and opens a window for further research into its role in RMS pathogenesis and for potential therapeutic targeting.
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Grants
- 451-03-9/2021-14/200042, 451-03-68/2022-14/200042, 451-03-47/2023-01/200042 Ministry of Science, Technological Development and Innovation of the Republic of Serbia
- 451-03-9/2021-14/200042, 451-03-68/2022-14/200042, 451-03-47/2023-01/200042 Ministry of Science, Technological Development and Innovation of the Republic of Serbia
- 451-03-9/2021-14/200042, 451-03-68/2022-14/200042, 451-03-47/2023-01/200042 Ministry of Science, Technological Development and Innovation of the Republic of Serbia
- 451-03-9/2021-14/200042, 451-03-68/2022-14/200042, 451-03-47/2023-01/200042 Ministry of Science, Technological Development and Innovation of the Republic of Serbia
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Affiliation(s)
- Emilija Milosevic
- Laboratory for Molecular Biology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, 11042, Belgrade, Serbia
| | - Mirjana Novkovic
- Laboratory for Molecular Biology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, 11042, Belgrade, Serbia
| | - Vittoria Cenni
- CNR Institute of Molecular Genetics "Luigi-Luca Cavalli-Sforza" Unit of Bologna, Via di Barbiano 1/10, 40136, Bologna, Italy
- IRCCS, Istituto Ortopedico Rizzoli, 40136, Bologna, Italy
| | - Alberto Bavelloni
- Laboratory of Experimental Oncology, IRCCS, Istituto Ortopedico Rizzoli, 40136, Bologna, Italy
| | - Snezana Kojic
- Laboratory for Molecular Biology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, 11042, Belgrade, Serbia.
| | - Jovana Jasnic
- Laboratory for Molecular Biology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, 11042, Belgrade, Serbia.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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7
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Klump BM, Schmidt JC. Advances in understanding telomerase assembly. Biochem Soc Trans 2023; 51:2093-2101. [PMID: 38108475 PMCID: PMC10754283 DOI: 10.1042/bst20230269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/30/2023] [Accepted: 12/04/2023] [Indexed: 12/19/2023]
Abstract
Telomerase is a complex ribonucleoprotein scaffolded by the telomerase RNA (TR). Telomere lengthening by telomerase is essential to maintain the proliferative potential of stem cells and germ cells, and telomerase is inappropriately activated in the majority of cancers. Assembly of TR with its 12 protein co-factors and the maturation of the 5'- and 3'-ends of TR have been the focus of intense research efforts over the past two decades. High-resolution Cryo-EM structures of human telomerase, high-throughput sequencing of the 3' end of TR, and live cell imaging of various telomerase components have significantly advanced our understanding of the molecular mechanisms that govern telomerase biogenesis, yet many important questions remain unaddressed. In this review, we will summarize these recent advances and highlight the remaining key questions with the ultimate goal of targeting telomerase assembly to suppress telomere maintenance in cancer cells or to promote telomerase activity in patients affected by telomere shortening disorders.
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Affiliation(s)
- Basma M. Klump
- Institute for Quantitative Health Sciences and Engineering, Michigan State University, East Lansing, MI, U.S.A
- College of Osteopathic Medicine, Michigan State University, East Lansing, MI, U.S.A
- Cell and Molecular Biology Graduate Program, College of Natural Sciences, Michigan State University, East Lansing, MI, U.S.A
| | - Jens C. Schmidt
- Institute for Quantitative Health Sciences and Engineering, Michigan State University, East Lansing, MI, U.S.A
- Department of Obstetrics, Gynecology, and Reproductive Biology, Michigan State University, East Lansing, MI, U.S.A
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Staněk D. Coilin and Cajal bodies. Nucleus 2023; 14:2256036. [PMID: 37682044 PMCID: PMC10494742 DOI: 10.1080/19491034.2023.2256036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/09/2023] Open
Abstract
The nucleus of higher eukaryotes contains a number of structures that concentrate specific biomolecules and play distinct roles in nuclear metabolism. In recent years, the molecular mechanisms controlling their formation have been intensively studied. In this brief review, I focus on coilin and Cajal bodies. Coilin is a key scaffolding protein of Cajal bodies that is evolutionarily conserved in metazoans. Cajal bodies are thought to be one of the archetypal nuclear structures involved in the metabolism of several short non-coding nuclear RNAs. Yet surprisingly little is known about the structure and function of coilin, and a comprehensive model to explain the origin of Cajal bodies is also lacking. Here, I summarize recent results on Cajal bodies and coilin and discuss them in the context of the last three decades of research in this field.
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Affiliation(s)
- David Staněk
- Laboratory of RNA Biology, Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
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Lettin L, Erbay B, Blair GE. Viruses and Cajal Bodies: A Critical Cellular Target in Virus Infection? Viruses 2023; 15:2311. [PMID: 38140552 PMCID: PMC10747631 DOI: 10.3390/v15122311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/24/2023] Open
Abstract
Nuclear bodies (NBs) are dynamic structures present in eukaryotic cell nuclei. They are not bounded by membranes and are often considered biomolecular condensates, defined structurally and functionally by the localisation of core components. Nuclear architecture can be reorganised during normal cellular processes such as the cell cycle as well as in response to cellular stress. Many plant and animal viruses target their proteins to NBs, in some cases triggering their structural disruption and redistribution. Although not all such interactions have been well characterised, subversion of NBs and their functions may form a key part of the life cycle of eukaryotic viruses that require the nucleus for their replication. This review will focus on Cajal bodies (CBs) and the viruses that target them. Since CBs are dynamic structures, other NBs (principally nucleoli and promyelocytic leukaemia, PML and bodies), whose components interact with CBs, will also be considered. As well as providing important insights into key virus-host cell interactions, studies on Cajal and associated NBs may identify novel cellular targets for development of antiviral compounds.
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Affiliation(s)
- Lucy Lettin
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK (B.E.)
| | - Bilgi Erbay
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK (B.E.)
- Moleküler Biyoloji ve Genetik Bölümü, Fen Fakültesi, Van Yuzuncu Yil University, Van 65140, Türkiye
| | - G. Eric Blair
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK (B.E.)
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10
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Kanno T, Chiou P, Wu MT, Lin WD, Matzke A, Matzke M. A GFP splicing reporter in a coilin mutant background reveals links between alternative splicing, siRNAs, and coilin function in Arabidopsis thaliana. G3 (Bethesda) 2023; 13:jkad175. [PMID: 37539868 PMCID: PMC10542627 DOI: 10.1093/g3journal/jkad175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 02/25/2023] [Accepted: 06/30/2023] [Indexed: 08/05/2023]
Abstract
Coilin is a scaffold protein essential for the structure of Cajal bodies, which are nucleolar-associated, nonmembranous organelles that coordinate the assembly of nuclear ribonucleoproteins (RNPs) including spliceosomal snRNPs. To study coilin function in plants, we conducted a genetic suppressor screen using a coilin (coi1) mutant in Arabidopsis thaliana and performed an immunoprecipitation-mass spectrometry analysis on coilin protein. The coi1 mutations modify alternative splicing of a GFP reporter gene, resulting in a hyper-GFP phenotype in young coi1 seedlings relative to the intermediate wild-type level. As shown here, this hyper-GFP phenotype is extinguished in older coi1 seedlings by posttranscriptional gene silencing triggered by siRNAs derived from aberrant splice variants of GFP pre-mRNA. In the coi1 suppressor screen, we identified suppressor mutations in WRAP53, a putative coilin-interacting protein; SMU2, a predicted splicing factor; and ZCH1, an incompletely characterized zinc finger protein. These suppressor mutations return the hyper-GFP fluorescence of young coi1 seedlings to the intermediate wild-type level. Additionally, coi1 zch1 mutants display more extensive GFP silencing and elevated levels of GFP siRNAs, suggesting the involvement of wild-type ZCH1 in siRNA biogenesis or stability. The immunoprecipitation-mass spectrometry analysis reinforced the roles of coilin in pre-mRNA splicing, nucleolar chromatin structure, and rRNA processing. The participation of coilin in these processes, at least some of which incorporate small RNAs, supports the hypothesis that coilin provides a chaperone for small RNA trafficking. Our study demonstrates the usefulness of the GFP splicing reporter for investigating alternative splicing, ribosome biogenesis, and siRNA-mediated silencing in the context of coilin function.
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Affiliation(s)
- Tatsuo Kanno
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115201, Taiwan
| | - Phebe Chiou
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115201, Taiwan
| | - Ming-Tsung Wu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115201, Taiwan
- Genenet Technology (UK) Limited, 128 City Road, London EC1V 2NX, UK
| | - Wen-Dar Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115201, Taiwan
| | - Antonius Matzke
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115201, Taiwan
| | - Marjori Matzke
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115201, Taiwan
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11
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Spechenkova N, Samarskaya VO, Kalinina NO, Zavriev SK, MacFarlane S, Love AJ, Taliansky M. Plant Poly(ADP-Ribose) Polymerase 1 Is a Potential Mediator of Cross-Talk between the Cajal Body Protein Coilin and Salicylic Acid-Mediated Antiviral Defence. Viruses 2023; 15:1282. [PMID: 37376582 DOI: 10.3390/v15061282] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 05/28/2023] [Accepted: 05/28/2023] [Indexed: 06/29/2023] Open
Abstract
The nucleolus and Cajal bodies (CBs) are sub-nuclear domains with well-known roles in RNA metabolism and RNA-protein assembly. However, they also participate in other important aspects of cell functioning. This study uncovers a previously unrecognised mechanism by which these bodies and their components regulate host defences against pathogen attack. We show that the CB protein coilin interacts with poly(ADP-ribose) polymerase 1 (PARP1), redistributes it to the nucleolus and modifies its function, and that these events are accompanied by substantial increases in endogenous concentrations of salicylic acid (SA), activation of SA-responsive gene expression and callose deposition leading to the restriction of tobacco rattle virus (TRV) systemic infection. Consistent with this, we also find that treatment with SA subverts the negative effect of the pharmacological PARP inhibitor 3-aminobenzamide (3AB) on plant recovery from TRV infection. Our results suggest that PARP1 could act as a key molecular actuator in the regulatory network which integrates coilin activities as a stress sensor for virus infection and SA-mediated antivirus defence.
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Affiliation(s)
- Nadezhda Spechenkova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia
| | - Viktoriya O Samarskaya
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia
| | - Natalya O Kalinina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Sergey K Zavriev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia
| | - S MacFarlane
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Andrew J Love
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Michael Taliansky
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
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12
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Majewska K, Wróblewska-Ankiewicz P, Rudzka M, Hyjek-Składanowska M, Gołębiewski M, Smoliński DJ, Kołowerzo-Lubnau A. Different Patterns of mRNA Nuclear Retention during Meiotic Prophase in Larch Microsporocytes. Int J Mol Sci 2021; 22:8501. [PMID: 34445207 PMCID: PMC8395157 DOI: 10.3390/ijms22168501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/18/2021] [Accepted: 08/04/2021] [Indexed: 12/12/2022] Open
Abstract
Recent studies show a crucial role of post-transcriptional processes in the regulation of gene expression. Our research has shown that mRNA retention in the nucleus plays a significant role in such regulation. We studied larch microsporocytes during meiotic prophase, characterized by pulsatile transcriptional activity. After each pulse, the transcriptional activity is silenced, but the transcripts synthesized at this time are not exported immediately to the cytoplasm but are retained in the cell nucleus and especially in Cajal bodies, where non-fully-spliced transcripts with retained introns are accumulated. Analysis of the transcriptome of these cells and detailed analysis of the nuclear retention and transport dynamics of several mRNAs revealed two main patterns of nuclear accumulation and transport. The majority of studied transcripts followed the first one, consisting of a more extended retention period and slow release to the cytoplasm. We have shown this in detail for the pre-mRNA and mRNA encoding RNA pol II subunit 10. In this pre-mRNA, a second (retained) intron is posttranscriptionally spliced at a precisely defined time. Fully mature mRNA is then released into the cytoplasm, where the RNA pol II complexes are produced. These proteins are necessary for transcription in the next pulse to occur.mRNAs encoding translation factors and SERRATE followed the second pattern, in which the retention period was shorter and transcripts were rapidly transferred to the cytoplasm. The presence of such a mechanism in various cell types from a diverse range of organisms suggests that it is an evolutionarily conserved mechanism of gene regulation.
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Affiliation(s)
- Karolina Majewska
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland; (K.M.); (P.W.-A.); (M.R.); (M.H.-S.)
- Centre For Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland;
| | - Patrycja Wróblewska-Ankiewicz
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland; (K.M.); (P.W.-A.); (M.R.); (M.H.-S.)
- Centre For Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland;
| | - Magda Rudzka
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland; (K.M.); (P.W.-A.); (M.R.); (M.H.-S.)
- Centre For Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland;
| | - Malwina Hyjek-Składanowska
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland; (K.M.); (P.W.-A.); (M.R.); (M.H.-S.)
- Centre For Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland;
| | - Marcin Gołębiewski
- Centre For Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland;
- Department of Plant Physiology and Biotechnology, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland
| | - Dariusz Jan Smoliński
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland; (K.M.); (P.W.-A.); (M.R.); (M.H.-S.)
- Centre For Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland;
| | - Agnieszka Kołowerzo-Lubnau
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland; (K.M.); (P.W.-A.); (M.R.); (M.H.-S.)
- Centre For Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland;
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13
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Bizarro J, Deryusheva S, Wacheul L, Gupta V, Ernst FGM, Lafontaine DLJ, Gall JG, Meier UT. Nopp140-chaperoned 2'-O-methylation of small nuclear RNAs in Cajal bodies ensures splicing fidelity. Genes Dev 2021; 35:1123-1141. [PMID: 34301768 PMCID: PMC8336889 DOI: 10.1101/gad.348660.121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 06/29/2021] [Indexed: 12/27/2022]
Abstract
In this study, Bizarro et al. sought to understand the function and subcellular site of snRNA modification, and found that Cajal body (CB) localization of the protein Nopp140 is essential for concentration of small Cajal body-specific ribonucleoproteins (scaRNPs) in nuclear condensate and that phosphorylation by casein kinase 2 (CK2) at ∼80 serines targets Nopp140 to CBs. Nopp140 knockdown-mediated release of scaRNPs from CBs severely compromises 2′-O-methylation of spliceosomal snRNAs, identifying CBs as the site of scaRNP catalysis. Spliceosomal small nuclear RNAs (snRNAs) are modified by small Cajal body (CB)-specific ribonucleoproteins (scaRNPs) to ensure snRNP biogenesis and pre-mRNA splicing. However, the function and subcellular site of snRNA modification are largely unknown. We show that CB localization of the protein Nopp140 is essential for concentration of scaRNPs in that nuclear condensate; and that phosphorylation by casein kinase 2 (CK2) at ∼80 serines targets Nopp140 to CBs. Transiting through CBs, snRNAs are apparently modified by scaRNPs. Indeed, Nopp140 knockdown-mediated release of scaRNPs from CBs severely compromises 2′-O-methylation of spliceosomal snRNAs, identifying CBs as the site of scaRNP catalysis. Additionally, alternative splicing patterns change indicating that these modifications in U1, U2, U5, and U12 snRNAs safeguard splicing fidelity. Given the importance of CK2 in this pathway, compromised splicing could underlie the mode of action of small molecule CK2 inhibitors currently considered for therapy in cholangiocarcinoma, hematological malignancies, and COVID-19.
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Affiliation(s)
| | | | - Ludivine Wacheul
- RNA Molecular Biology, Fonds National de la Recherche Scientifique (FRS/FNRS), Université Libre de Bruxelles (ULB), B-6041 Gosselies, Belgium
| | - Varun Gupta
- Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Felix G M Ernst
- RNA Molecular Biology, Fonds National de la Recherche Scientifique (FRS/FNRS), Université Libre de Bruxelles (ULB), B-6041 Gosselies, Belgium
| | - Denis L J Lafontaine
- RNA Molecular Biology, Fonds National de la Recherche Scientifique (FRS/FNRS), Université Libre de Bruxelles (ULB), B-6041 Gosselies, Belgium
| | - Joseph G Gall
- Carnegie Institution for Science, Baltimore, Maryland 21218, USA
| | - U Thomas Meier
- Albert Einstein College of Medicine, Bronx, New York 10461, USA
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14
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Xu R, Yang Y, Zheng X. Unique structural features of the adenylate kinase hCINAP/AK6 and its multifaceted functions in carcinogenesis and tumor progression. FEBS Lett 2021; 595:2071-2084. [PMID: 34245011 DOI: 10.1002/1873-3468.14158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/01/2021] [Accepted: 07/01/2021] [Indexed: 12/30/2022]
Abstract
Human coilin-interacting nuclear ATPase protein (hCINAP), also known as adenylate kinase 6 (AK6), is an atypical adenylate kinase with critical roles in many biological processes, including gene transcription, ribosome synthesis, cell metabolism, cell proliferation and apoptosis, DNA damage responses, and genome stability. Furthermore, hCINAP/AK6 dysfunction is associated with cancer and various inflammatory diseases. In this review, we summarize the structural features and biological roles of hCINAP in several important signaling pathways, as well as its connection with tumor onset and progression.
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Affiliation(s)
- Ruidan Xu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Beijing, China
| | - Yongfeng Yang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Beijing, China
| | - Xiaofeng Zheng
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Beijing, China
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15
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Rossi S, Rompietti V, Antonucci Y, Giovannini D, Scopa C, Scaricamazza S, Scardigli R, Cestra G, Serafino A, Carrì MT, D'Ambrosi N, Cozzolino M. UsnRNP trafficking is regulated by stress granules and compromised by mutant ALS proteins. Neurobiol Dis 2020; 138:104792. [PMID: 32027933 DOI: 10.1016/j.nbd.2020.104792] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/24/2020] [Accepted: 02/03/2020] [Indexed: 12/13/2022] Open
Abstract
Activation of the integrated stress response (ISR), alterations in nucleo-cytoplasmic (N/C) transport and changes in alternative splicing regulation are all common traits of the pathogenesis of Amyotrophic Lateral Sclerosis (ALS). However, whether these processes act independently from each other, or are part of a coordinated mechanism of gene expression regulation that is affected in pathogenic conditions, is still rather undefined. To answer these questions, in this work we set out to characterise the functional connections existing between ISR activation and nucleo-cytosol trafficking and nuclear localization of spliceosomal U-rich small nuclear ribonucleoproteins (UsnRNPs), the core constituents of the spliceosome, and to study how ALS-linked mutant proteins affect this interplay. Activation of the ISR induces a profound reorganization of nuclear Gems and Cajal bodies, the membrane-less particles that assist UsnRNP maturation and storage. This effect requires the cytoplasmic assembly of SGs and is associated to the disturbance of the nuclear import of UsnRNPs by the snurportin-1/importin-β1 system. Notably, these effects are reversed by both inhibiting the ISR or upregulating importin-β1. This indicates that SGs are major determinants of Cajal bodies assembly and that the modulation of N/C trafficking of UsnRNPs might control alternative splicing in response to stress. Importantly, the dismantling of nuclear Gems and Cajal bodies by ALS-linked mutant FUS or C9orf72-derived dipeptide repeat proteins is halted by overexpression of importin-β1, but not by inhibition of the ISR. This suggests that changes in the nuclear localization of the UsnRNP complexes induced by mutant ALS proteins are uncoupled from ISR activation, and that defects in the N/C trafficking of UsnRNPs might play a role in ALS pathogenesis.
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Affiliation(s)
- Simona Rossi
- Istituto di Farmacologia Traslazionale (IFT), CNR, 00133 Rome, Italy; Dipartimento di Biologia, Università di Roma "Tor Vergata", Rome, Italy.
| | | | - Ylenia Antonucci
- Istituto di Farmacologia Traslazionale (IFT), CNR, 00133 Rome, Italy
| | | | - Chiara Scopa
- European Brain Research Institute (EBRI), Rome, Italy
| | | | - Raffaella Scardigli
- Istituto di Farmacologia Traslazionale (IFT), CNR, 00133 Rome, Italy; European Brain Research Institute (EBRI), Rome, Italy
| | - Gianluca Cestra
- Istituto di Biologia e Patologia Molecolari (IBPM), CNR, Rome, Italy; Dipartimento di Biologia e Biotecnologia "Charles Darwin", Università di Roma "Sapienza", Rome, Italy
| | | | | | - Nadia D'Ambrosi
- Dipartimento di Biologia, Università di Roma "Tor Vergata", Rome, Italy
| | - Mauro Cozzolino
- Istituto di Farmacologia Traslazionale (IFT), CNR, 00133 Rome, Italy.
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16
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Abstract
RNA granules are dynamic cellular foci that are widely spread in eukaryotic cells and play essential roles in cell growth and development, and immune and stress responses. Different types of granules can be distinguished, each with a specific function and playing a role in, for example, RNA transcription, modification, processing, decay, translation, and arrest. By means of communication and exchange of (shared) components, they form a large regulatory network in cells. Viruses have been reported to interact with one or more of these either cytoplasmic or nuclear granules, and act either proviral, to enable and support viral infection and facilitate viral movement, or antiviral, protecting or clearing hosts from viral infection. This review describes an overview and recent progress on cytoplasmic and nuclear RNA granules and their interplay with virus infection, first in animal systems and as a prelude to the status and current developments on plant viruses, which have been less well studied on this thus far.
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Affiliation(s)
- Min Xu
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
- Laboratory of Virology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
| | - Magdalena J Mazur
- Laboratory of Virology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
| | - Xiaorong Tao
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Richard Kormelink
- Laboratory of Virology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
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17
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Söding J, Zwicker D, Sohrabi-Jahromi S, Boehning M, Kirschbaum J. Mechanisms for Active Regulation of Biomolecular Condensates. Trends Cell Biol 2019; 30:4-14. [PMID: 31753533 DOI: 10.1016/j.tcb.2019.10.006] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/17/2019] [Accepted: 10/18/2019] [Indexed: 12/31/2022]
Abstract
Liquid-liquid phase separation is a key organizational principle in eukaryotic cells, on par with intracellular membranes. It allows cells to concentrate specific proteins into condensates, increasing reaction rates and achieving switch-like regulation. We propose two active mechanisms that can explain how cells regulate condensate formation and size. In both, the cell regulates the activity of an enzyme, often a kinase, that adds post-translational modifications to condensate proteins. In enrichment inhibition, the enzyme enriches in the condensate and weakens interactions, as seen in stress granules (SGs), Cajal bodies, and P granules. In localization-induction, condensates form around immobilized enzymes that strengthen interactions, as observed in DNA repair, transmembrane signaling, and microtubule assembly. These models can guide studies into the many emerging roles of biomolecular condensates.
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Affiliation(s)
- Johannes Söding
- Quantitative Biology and Bioinformatics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
| | - David Zwicker
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany
| | - Salma Sohrabi-Jahromi
- Quantitative Biology and Bioinformatics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Marc Boehning
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Jan Kirschbaum
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany
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18
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Shaw J, Yu C, Makhotenko AV, Makarova SS, Love AJ, Kalinina NO, MacFarlane S, Chen J, Taliansky ME. Interaction of a plant virus protein with the signature Cajal body protein coilin facilitates salicylic acid-mediated plant defence responses. New Phytol 2019; 224:439-453. [PMID: 31215645 DOI: 10.1111/nph.15994] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 06/06/2019] [Indexed: 05/22/2023]
Abstract
In addition to well-known roles in RNA metabolism, the nucleolus and Cajal bodies (CBs), both located within the nucleus, are involved in plant responses to biotic and abiotic stress. Previously we showed that plants in which expression of the CB protein coilin is downregulated are more susceptible to certain viruses including tobacco rattle virus (TRV), suggesting a role of coilin in antiviral defence. Experiments with coilin-deficient plants and the deletion mutant of the TRV 16K protein showed that both 16K and coilin are required for restriction of systemic TRV infection. The potential mechanisms of coilin-mediated antiviral defence were elucidated via experiments involving co-immunoprecipitation, use of NahG transgenic plants deficient in salicylic acid (SA) accumulation, measurement of endogenous SA concentrations and assessment of SA-responsive gene expression. Here we show that TRV 16K interacts with and relocalizes coilin to the nucleolus. In wild-type plants these events are accompanied by activation of SA-responsive gene expression and restriction of TRV systemic infection. By contrast, viral systemic spread was enhanced in NahG plants, implicating SA in these processes. Our findings suggest that coilin is involved in plant defence, responding to TRV infection by recognition of the TRV-encoded 16K protein and activating SA-dependent defence pathways.
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Affiliation(s)
- Jane Shaw
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Chulang Yu
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
- State Key Laboratory for Quality and Safety of Agro-products, Institute of Plant Virology, Ningbo University, Ningbo, 117997, China
| | - Antonida V Makhotenko
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the RAS, Moscow, 117997, Russia
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia
| | - Svetlana S Makarova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the RAS, Moscow, 117997, Russia
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia
| | - Andrew J Love
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Natalia O Kalinina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the RAS, Moscow, 117997, Russia
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia
| | - Stuart MacFarlane
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Jianping Chen
- State Key Laboratory for Quality and Safety of Agro-products, Institute of Plant Virology, Ningbo University, Ningbo, 117997, China
| | - Michael E Taliansky
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the RAS, Moscow, 117997, Russia
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19
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Jonik-Nowak B, Menneteau T, Fesquet D, Baldin V, Bonne-Andrea C, Méchali F, Fabre B, Boisguerin P, de Rossi S, Henriquet C, Pugnière M, Ducoux-Petit M, Burlet-Schiltz O, Lamond AI, Fort P, Boulon S, Bousquet MP, Coux O. PIP30/FAM192A is a novel regulator of the nuclear proteasome activator PA28γ. Proc Natl Acad Sci U S A 2018; 115:E6477-E6486. [PMID: 29934401 PMCID: PMC6048556 DOI: 10.1073/pnas.1722299115] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PA28γ is a nuclear activator of the 20S proteasome involved in the regulation of several essential cellular processes, such as cell proliferation, apoptosis, nuclear dynamics, and cellular stress response. Unlike the 19S regulator of the proteasome, which specifically recognizes ubiquitylated proteins, PA28γ promotes the degradation of several substrates by the proteasome in an ATP- and ubiquitin-independent manner. However, its exact mechanisms of action are unclear and likely involve additional partners that remain to be identified. Here we report the identification of a cofactor of PA28γ, PIP30/FAM192A. PIP30 binds directly and specifically via its C-terminal end and in an interaction stabilized by casein kinase 2 phosphorylation to both free and 20S proteasome-associated PA28γ. Its recruitment to proteasome-containing complexes depends on PA28γ and its expression increases the association of PA28γ with the 20S proteasome in cells. Further dissection of its possible roles shows that PIP30 alters PA28γ-dependent activation of peptide degradation by the 20S proteasome in vitro and negatively controls in cells the presence of PA28γ in Cajal bodies by inhibition of its association with the key Cajal body component coilin. Taken together, our data show that PIP30 deeply affects PA28γ interactions with cellular proteins, including the 20S proteasome, demonstrating that it is an important regulator of PA28γ in cells and thus a new player in the control of the multiple functions of the proteasome within the nucleus.
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Affiliation(s)
- Beata Jonik-Nowak
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34090 Montpellier, France
| | - Thomas Menneteau
- Institut de Pharmacologie et Biologie Structurale (IPBS), CNRS, Université de Toulouse-Université Paul Sabatier, 31062 Toulouse, France
| | - Didier Fesquet
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34090 Montpellier, France
| | - Véronique Baldin
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34090 Montpellier, France
| | - Catherine Bonne-Andrea
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34090 Montpellier, France
| | - Francisca Méchali
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34090 Montpellier, France
| | - Bertrand Fabre
- Institut de Pharmacologie et Biologie Structurale (IPBS), CNRS, Université de Toulouse-Université Paul Sabatier, 31062 Toulouse, France
| | - Prisca Boisguerin
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34090 Montpellier, France
| | - Sylvain de Rossi
- Montpellier Ressources Imagerie (MRI) Facility, Biocampus UMS3426, CNRS, 34090 Montpellier, France
| | - Corinne Henriquet
- Institut de Recherche en Cancérologie de Montpellier (IRCM) - INSERM U1194, Institut Régional du Cancer de Montpellier, Université de Montpellier, F-34298 Montpellier, France
| | - Martine Pugnière
- Institut de Recherche en Cancérologie de Montpellier (IRCM) - INSERM U1194, Institut Régional du Cancer de Montpellier, Université de Montpellier, F-34298 Montpellier, France
| | - Manuelle Ducoux-Petit
- Institut de Pharmacologie et Biologie Structurale (IPBS), CNRS, Université de Toulouse-Université Paul Sabatier, 31062 Toulouse, France
| | - Odile Burlet-Schiltz
- Institut de Pharmacologie et Biologie Structurale (IPBS), CNRS, Université de Toulouse-Université Paul Sabatier, 31062 Toulouse, France
| | - Angus I Lamond
- Centre for Gene Regulation and Expression, School of Life Sciences, DD1 5HL Dundee, United Kingdom
| | - Philippe Fort
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34090 Montpellier, France
| | - Séverine Boulon
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34090 Montpellier, France;
| | - Marie-Pierre Bousquet
- Institut de Pharmacologie et Biologie Structurale (IPBS), CNRS, Université de Toulouse-Université Paul Sabatier, 31062 Toulouse, France;
| | - Olivier Coux
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34090 Montpellier, France;
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20
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Vindry C, Marnef A, Broomhead H, Twyffels L, Ozgur S, Stoecklin G, Llorian M, Smith CW, Mata J, Weil D, Standart N. Dual RNA Processing Roles of Pat1b via Cytoplasmic Lsm1-7 and Nuclear Lsm2-8 Complexes. Cell Rep 2018; 20:1187-1200. [PMID: 28768202 PMCID: PMC5554784 DOI: 10.1016/j.celrep.2017.06.091] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/12/2017] [Accepted: 06/28/2017] [Indexed: 12/16/2022] Open
Abstract
Pat1 RNA-binding proteins, enriched in processing bodies (P bodies), are key players in cytoplasmic 5' to 3' mRNA decay, activating decapping of mRNA in complex with the Lsm1-7 heptamer. Using co-immunoprecipitation and immunofluorescence approaches coupled with RNAi, we provide evidence for a nuclear complex of Pat1b with the Lsm2-8 heptamer, which binds to the spliceosomal U6 small nuclear RNA (snRNA). Furthermore, we establish the set of interactions connecting Pat1b/Lsm2-8/U6 snRNA/SART3 and additional U4/U6.U5 tri-small nuclear ribonucleoprotein particle (tri-snRNP) components in Cajal bodies, the site of snRNP biogenesis. RNA sequencing following Pat1b depletion revealed the preferential upregulation of mRNAs normally found in P bodies and enriched in 3' UTR AU-rich elements. Changes in >180 alternative splicing events were also observed, characterized by skipping of regulated exons with weak donor sites. Our data demonstrate the dual role of a decapping enhancer in pre-mRNA processing as well as in mRNA decay via distinct nuclear and cytoplasmic Lsm complexes.
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Affiliation(s)
- Caroline Vindry
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Aline Marnef
- LBCMCP, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse UT3, 31062 Toulouse, France
| | - Helen Broomhead
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Laure Twyffels
- Center for Microscopy and Molecular Imaging (CMMI), Université libre de Bruxelles (ULB), 6041 Gosselies, Belgium
| | - Sevim Ozgur
- Max Planck Institute of Biochemistry, Am Klopferspitz, 82152 Martinsried, Germany
| | - Georg Stoecklin
- Division of Biochemistry, Center for Biomedicine and Medical Technology Mannheim, Medical Faculty Mannheim, Heidelberg University, 69047 Heidelberg, Germany; Center for Molecular Biology of Heidelberg University (ZMBH), 69047 Heidelberg, Germany; German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 68167 Mannheim, Germany
| | - Miriam Llorian
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Christopher W Smith
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Juan Mata
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Dominique Weil
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie du développement Paris Seine - Institut de Biologie Paris Seine (LBD - IBPS), 75005 Paris, France
| | - Nancy Standart
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK.
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21
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Meier ID, Walker MP, Matera AG. Gemin4 is an essential gene in mice, and its overexpression in human cells causes relocalization of the SMN complex to the nucleoplasm. Biol Open 2018; 7:bio.032409. [PMID: 29371219 PMCID: PMC5861365 DOI: 10.1242/bio.032409] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Gemin4 is a member of the Survival Motor Neuron (SMN) protein complex, which is responsible for the assembly and maturation of Sm-class small nuclear ribonucleoproteins (snRNPs). In metazoa, Sm snRNPs are assembled in the cytoplasm and subsequently imported into the nucleus. We previously showed that the SMN complex is required for snRNP import in vitro, although it remains unclear which specific components direct this process. Here, we report that Gemin4 overexpression drives SMN and the other Gemin proteins from the cytoplasm into the nucleus. Moreover, it disrupts the subnuclear localization of the Cajal body marker protein, coilin, in a dose-dependent manner. We identified three putative nuclear localization signal (NLS) motifs within Gemin4, one of which is necessary and sufficient to direct nuclear import. Overexpression of Gemin4 constructs lacking this NLS sequestered Gemin3 and, to a lesser extent Gemin2, in the cytoplasm but had little effect on the nuclear accumulation of SMN. We also investigated the effects of Gemin4 depletion in the laboratory mouse, Mus musculus. Gemin4 null mice die early in embryonic development, demonstrating that Gemin4 is an essential mammalian protein. When crossed onto a severe SMA mutant background, heterozygous loss of Gemin4 failed to modify the early postnatal mortality phenotype of SMA type I (Smn−/−;SMN2+/+) mice. We conclude that Gemin4 plays an essential role in mammalian snRNP biogenesis, and may facilitate import of the SMN complex (or subunits thereof) into the nucleus. Summary:Gemin4 loss-of-function is recessive lethal in mice, whereas in cell culture its overexpression results in a dominant, gain-of-function relocalization of SMN and other Gemin proteins to the nucleus.
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Affiliation(s)
- Ingo D Meier
- Integrative Program for Biological and Genome Sciences, Departments of Biology and Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599-3280, USA
| | - Michael P Walker
- Integrative Program for Biological and Genome Sciences, Departments of Biology and Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599-3280, USA.,Department of Genetics, Case Western Reserve University, Cleveland, OH 44106-4955, USA
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22
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Lafarga V, Tapia O, Sharma S, Bengoechea R, Stoecklin G, Lafarga M, Berciano MT. CBP-mediated SMN acetylation modulates Cajal body biogenesis and the cytoplasmic targeting of SMN. Cell Mol Life Sci 2018; 75:527-46. [PMID: 28879433 DOI: 10.1007/s00018-017-2638-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 08/09/2017] [Accepted: 08/29/2017] [Indexed: 01/12/2023]
Abstract
The survival of motor neuron (SMN) protein plays an essential role in the biogenesis of spliceosomal snRNPs and the molecular assembly of Cajal bodies (CBs). Deletion of or mutations in the SMN1 gene cause spinal muscular atrophy (SMA) with degeneration and loss of motor neurons. Reduced SMN levels in SMA lead to deficient snRNP biogenesis with consequent splicing pathology. Here, we demonstrate that SMN is a novel and specific target of the acetyltransferase CBP (CREB-binding protein). Furthermore, we identify lysine (K) 119 as the main acetylation site in SMN. Importantly, SMN acetylation enhances its cytoplasmic localization, causes depletion of CBs, and reduces the accumulation of snRNPs in nuclear speckles. In contrast, the acetylation-deficient SMNK119R mutant promotes formation of CBs and a novel category of promyelocytic leukemia (PML) bodies enriched in this protein. Acetylation increases the half-life of SMN protein, reduces its cytoplasmic diffusion rate and modifies its interactome. Hence, SMN acetylation leads to its dysfunction, which explains the ineffectiveness of HDAC (histone deacetylases) inhibitors in SMA therapy despite their potential to increase SMN levels.
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23
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Tapia O, Narcís JO, Riancho J, Tarabal O, Piedrafita L, Calderó J, Berciano MT, Lafarga M. Cellular bases of the RNA metabolism dysfunction in motor neurons of a murine model of spinal muscular atrophy: Role of Cajal bodies and the nucleolus. Neurobiol Dis 2017; 108:83-99. [PMID: 28823932 DOI: 10.1016/j.nbd.2017.08.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 08/01/2017] [Accepted: 08/16/2017] [Indexed: 02/06/2023] Open
Abstract
Spinal muscular atrophy (SMA) is caused by a homozygous deletion or mutation in the survival motor neuron 1 (SMN1) gene that leads to reduced levels of SMN protein resulting in degeneration of motor neurons (MNs). The best known functions of SMN is the biogenesis of spliceosomal snRNPs. Linked to this function, Cajal bodies (CBs) are involved in the assembly of spliceosomal (snRNPs) and nucleolar (snoRNPs) ribonucleoproteins required for pre-mRNA and pre-rRNA processing. Recent studies support that the interaction between CBs and nucleoli, which are especially prominent in neurons, is essential for the nucleolar rRNA homeostasis. We use the SMN∆7 murine model of type I SMA to investigate the cellular basis of the dysfunction of RNA metabolism in MNs. SMN deficiency in postnatal MNs produces a depletion of functional CBs and relocalization of coilin, which is a scaffold protein of CBs, in snRNP-free perinucleolar caps or within the nucleolus. Disruption of CBs is the earliest nuclear sign of MN degeneration. We demonstrate that depletion of CBs, with loss of CB-nucleolus interactions, induces a progressive nucleolar dysfunction in ribosome biogenesis. It includes reorganization and loss of nucleolar transcription units, segregation of dense fibrillar and granular components, retention of SUMO-conjugated proteins in intranucleolar bodies and a reactive, compensatory, up-regulation of mature 18S rRNA and genes encoding key nucleolar proteins, such as upstream binding factor, fibrillarin, nucleolin and nucleophosmin. We propose that CB depletion and nucleolar alterations are essential components of the dysfunction of RNA metabolism in SMA.
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Affiliation(s)
- Olga Tapia
- Department of Anatomy and Cell Biology and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", University of Cantabria-IDIVAL, Santander, Spain
| | - Josep Oriol Narcís
- Department of Anatomy and Cell Biology and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", University of Cantabria-IDIVAL, Santander, Spain
| | - Javier Riancho
- Service of Neurology, University Hospital Marqués de Valdecilla-IDIVAL-CIBERNED, Santander, Spain
| | - Olga Tarabal
- Department of Experimental Medicine, School of Medicine, University of Lleida and "Institut de Recerca Biomèdica de Lleida" (IRBLLEIDA), Lleida, Spain
| | - Lídia Piedrafita
- Department of Experimental Medicine, School of Medicine, University of Lleida and "Institut de Recerca Biomèdica de Lleida" (IRBLLEIDA), Lleida, Spain
| | - Jordi Calderó
- Department of Experimental Medicine, School of Medicine, University of Lleida and "Institut de Recerca Biomèdica de Lleida" (IRBLLEIDA), Lleida, Spain
| | - Maria T Berciano
- Department of Anatomy and Cell Biology and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", University of Cantabria-IDIVAL, Santander, Spain
| | - Miguel Lafarga
- Department of Anatomy and Cell Biology and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", University of Cantabria-IDIVAL, Santander, Spain.
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24
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Abstract
The assembly of specialized sub-nuclear microenvironments known as nuclear bodies (NBs) is important for promoting efficient nuclear function. In particular, the Cajal body (CB), a prominent NB that facilitates spliceosomal snRNP biogenesis, assembles in response to genomic cues. Here, we detail the factors that regulate CB assembly and structural maintenance. These include the importance of transcription at nucleating gene loci, the grouping of these genes on human chromosomes 1, 6 and 17, as well as cell cycle and biochemical regulation of CB protein function. We also speculate on the correlation between CB formation and RNA splicing levels in neurons and cancer. The timing and location of these specific molecular events is critical to CB assembly and its contribution to genome function. However, further work is required to explore the emerging biophysical characteristics of CB assembly and the impact upon subsequent genome reorganization.
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Affiliation(s)
- Iain A. Sawyer
- Department of Cell Biology, Rosalind Franklin University of Medicine & Science, Chicago Medical School, North Chicago, IL, USA
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Gordon L. Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Miroslav Dundr
- Department of Cell Biology, Rosalind Franklin University of Medicine & Science, Chicago Medical School, North Chicago, IL, USA
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25
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Ohtani M. Plant snRNP Biogenesis: A Perspective from the Nucleolus and Cajal Bodies. Front Plant Sci 2017; 8:2184. [PMID: 29354141 PMCID: PMC5758608 DOI: 10.3389/fpls.2017.02184] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 12/12/2017] [Indexed: 05/20/2023]
Abstract
Small nuclear ribonucleoproteins (snRNPs) are protein-RNA complexes composed of specific snRNP-associated proteins along with small nuclear RNAs (snRNAs), which are non-coding RNA molecules abundant in the nucleus. snRNPs mainly function as core components of the spliceosome, the molecular machinery for pre-mRNA splicing. Thus, snRNP biogenesis is a critical issue for plants, essential for the determination of a cell's activity through the regulation of gene expression. The complex process of snRNP biogenesis is initiated by transcription of the snRNA in the nucleus, continues in the cytoplasm, and terminates back in the nucleus. Critical steps of snRNP biogenesis, such as chemical modification of the snRNA and snRNP maturation, occur in the nucleolus and its related sub-nuclear structures, Cajal bodies. In this review, I discuss roles for the nucleolus and Cajal bodies in snRNP biogenesis, and a possible linkage between the regulation of snRNP biogenesis and plant development and environmental responses.
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Affiliation(s)
- Misato Ohtani
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- *Correspondence: Misato Ohtani,
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26
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Abstract
Nuclear bodies contribute to non-random organization of the human genome and nuclear function. Using a major prototypical nuclear body, the Cajal body, as an example, we suggest that these structures assemble at specific gene loci located across the genome as a result of high transcriptional activity. Subsequently, target genes are physically clustered in close proximity in Cajal body-containing cells. However, Cajal bodies are observed in only a limited number of human cell types, including neuronal and cancer cells. Ultimately, Cajal body depletion perturbs splicing kinetics by reducing target small nuclear RNA (snRNA) transcription and limiting the levels of spliceosomal snRNPs, including their modification and turnover following each round of RNA splicing. As such, Cajal bodies are capable of shaping the chromatin interaction landscape and the transcriptome by influencing spliceosome kinetics. Future studies should concentrate on characterizing the direct influence of Cajal bodies upon snRNA gene transcriptional dynamics. Also see the video abstract here.
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Affiliation(s)
- Iain A Sawyer
- Department of Cell Biology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA.,Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - David Sturgill
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Myong-Hee Sung
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Miroslav Dundr
- Department of Cell Biology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
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27
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Abstract
Cajal bodies (CBs) are distinct sub-nuclear structures that are present in eukaryotic living cells and are often associated with the nucleolus. CBs play important roles in RNA metabolism and formation of RNPs involved in transcription, splicing, ribosome biogenesis, and telomere maintenance. Besides these primary roles, CBs appear to be involved in additional functions that may not be directly related to RNA metabolism and RNP biogenesis. In this review, we assess possible roles of plant CBs in RNA regulatory pathways such as nonsense-mediated mRNA decay and RNA silencing. We also summarize recent progress and discuss new non-canonical functions of plant CBs in responses to stress and disease. It is hypothesized that CBs can regulate these responses via their interaction with poly(ADP ribose)polymerase (PARP), which is known to play an important role in various physiological processes including responses to biotic and abiotic stresses. It is suggested that CBs and their components modify PARP activities and functions.
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Affiliation(s)
- Andrew J Love
- a Cell and Molecular Sciences , James Hutton Institute , Invergowrie, Dundee , UK
| | - Chulang Yu
- b State Key Laboratory Breeding Base for Sustainable Pest and Disease Control, Key Laboratory of Biotechnology in Plant Protection of MOA and Zhejiang Province , Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences , Hangzhou , China
| | - Natalia V Petukhova
- a Cell and Molecular Sciences , James Hutton Institute , Invergowrie, Dundee , UK
| | - Natalia O Kalinina
- c A.N. Belozersky Institute of Physico-Chemical Biology , Lomonosov Moscow State University , Leninskie Gory, Moscow , Russia
| | - Jianping Chen
- b State Key Laboratory Breeding Base for Sustainable Pest and Disease Control, Key Laboratory of Biotechnology in Plant Protection of MOA and Zhejiang Province , Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences , Hangzhou , China
| | - Michael E Taliansky
- a Cell and Molecular Sciences , James Hutton Institute , Invergowrie, Dundee , UK.,b State Key Laboratory Breeding Base for Sustainable Pest and Disease Control, Key Laboratory of Biotechnology in Plant Protection of MOA and Zhejiang Province , Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences , Hangzhou , China
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28
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Vogan JM, Zhang X, Youmans DT, Regalado SG, Johnson JZ, Hockemeyer D, Collins K. Minimized human telomerase maintains telomeres and resolves endogenous roles of H/ACA proteins, TCAB1, and Cajal bodies. eLife 2016; 5. [PMID: 27525486 PMCID: PMC5005035 DOI: 10.7554/elife.18221] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 08/14/2016] [Indexed: 01/22/2023] Open
Abstract
We dissected the importance of human telomerase biogenesis and trafficking pathways for telomere maintenance. Biological stability of human telomerase RNA (hTR) relies on H/ACA proteins, but other eukaryotes use other RNP assembly pathways. To investigate additional rationale for human telomerase assembly as H/ACA RNP, we developed a minimized cellular hTR. Remarkably, with only binding sites for telomerase reverse transcriptase (TERT), minimized hTR assembled biologically active enzyme. TERT overexpression was required for cellular interaction with minimized hTR, indicating that H/ACA RNP assembly enhances endogenous hTR-TERT interaction. Telomere maintenance by minimized telomerase was unaffected by the elimination of the telomerase holoenzyme Cajal body chaperone TCAB1 or the Cajal body scaffold protein Coilin. Surprisingly, wild-type hTR also maintained and elongated telomeres in TCAB1 or Coilin knockout cells, with distinct changes in telomerase action. Overall, we elucidate trafficking requirements for telomerase biogenesis and function and expand mechanisms by which altered telomere maintenance engenders human disease. DOI:http://dx.doi.org/10.7554/eLife.18221.001 Most cells in the human body can only divide a certain number of times before they die. This is because regions called telomeres at the ends of the cell’s DNA get shorter every time the cell divides, to the point that they disappear and halt cell growth. Particular types of cells – including some stem cells and cancer cells – can avoid death and continue to divide indefinitely because they produce an enzyme called telomerase that extends the telomere regions. The process by which the telomerase enzyme binds to and lengthens the DNA has several stages and involves many different proteins. One of the stages involves moving telomerase from the sites where it is assembled within the cell to a place where it can find telomeres in need of elongation (different areas within the cell compartment called the nucleus). Structures inside the nucleus called Cajal bodies were thought to help the enzyme bind to the telomeres. It is not clear why the process of extending telomeres is so complex. Vogan et al. engineered altered versions of telomerase that use simpler pathways to bind to and act on telomeres and inserted them into ‘pluripotent’ stem cells and cancer cells from humans. The experiments show that a pathway that helps to move the enzyme from its normal storage place in the nucleus is less important for extending telomeres in cancer cells than in pluripotent stem cells. Unexpectedly, Cajal bodies are not critical for bringing telomerase into contact with the telomeres in either cell type. The findings show that many of the proteins involved in extending telomeres in cells are not strictly essential. The simplified pathway developed by Vogan et al. opens up new opportunities to study the details of how telomerase extends telomeres. DOI:http://dx.doi.org/10.7554/eLife.18221.002
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Affiliation(s)
- Jacob M Vogan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Xiaozhu Zhang
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Daniel T Youmans
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Samuel G Regalado
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Joshua Z Johnson
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Dirk Hockemeyer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Kathleen Collins
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
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29
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Abstract
A concern in the field of genomics is the proper interpretation of large, high-throughput sequencing datasets. The use of DNA FISH followed by high-content microscopy is a valuable tool for validation and contextualization of frequently occurring gene pairing events at the single-cell level identified by deep sequencing. However, these techniques possess certain limitations. Firstly, they do not permit the study of colocalization of many gene loci simultaneously. Secondly, the direct assessment of the relative position of many clustered gene loci within their respective chromosome territories is impossible. Thus, methods are required to advance the study of higher-order nuclear and cellular organization. Here, we describe a multiplexed DNA FISH technique combined with indirect immunofluorescence to study the relative position of 6 distinct genomic or cellular structures. This can be achieved in a single hybridization step using spectral imaging during image acquisition and linear unmixing. Here, we detail the use of this method to quantify gene pairing between highly expressed spliceosomal genes and compare these data to randomly positioned in silico simulated gene clusters. This is a potentially universally applicable approach for the validation of 3C-based technologies, deep imaging of spatial organization within the nucleus and global cellular organization.
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Affiliation(s)
- Iain A Sawyer
- a Department of Cell Biology , Rosalind Franklin University of Medicine & Science, Chicago Medical School , North Chicago , IL , USA.,b Laboratory of Receptor Biology and Gene Expression , National Cancer Institute, National Institutes of Health , Bethesda , MD , USA
| | - Sergei P Shevtsov
- a Department of Cell Biology , Rosalind Franklin University of Medicine & Science, Chicago Medical School , North Chicago , IL , USA
| | - Miroslav Dundr
- a Department of Cell Biology , Rosalind Franklin University of Medicine & Science, Chicago Medical School , North Chicago , IL , USA
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30
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Niedojadło J, Dełeńko K, Niedojadło K. Regulation of poly(A) RNA retention in the nucleus as a survival strategy of plants during hypoxia. RNA Biol 2016; 13:531-43. [PMID: 27002417 DOI: 10.1080/15476286.2016.1166331] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Last finding indicates that post-transcriptional processes are significant in low-oxygen conditions, but their nature is poorly understood. Here, we localized poly(A) RNA and mRNA coding proteins involved and not involved with resistance to hypoxia in Lupinus luteus and Arabidopsis thaliana during submergence and after recovery of aerobic conditions. We showed a strong nuclear accumulation of poly(A) RNA and 6 of 7 studied mRNAs with a concurrent strong reduction in RNA polymerase II transcription during hypoxia. In this study, the nucleus did not accumulate mRNA of the ADH1 (alcohol dehydrogenase 1) gene, which is a core hypoxia gene. The RNA accumulation in the nucleus is among the mechanisms of post-transcriptional gene regulation that prevents translation. However re-aeration was accompanied by a strong increase in the amount of the mRNAs in the cytoplasm and a simultaneous decrease in nuclear mRNAs. This finding indicates that the nucleus is a storage site for those of mRNAs which are not involved in the response to hypoxia for use by the plants after the hypoxic stress. In this study, the highest intensity of RNA accumulation occurred in Cajal bodies (CBs); the intensity of accumulation was inversely correlated with transcription. Under hypoxia, ncb-1 mutants of Arabidopsis thaliana with a complete absence of CBs died sooner than wild type (WT), accompanied by a strong reduction in the level of poly(A) RNA in the nucleus. These results suggest that the CBs not only participate in the storage of the nuclear RNA, but they also could take part in its stabilization under low-oxygen conditions.
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Affiliation(s)
- Janusz Niedojadło
- a Department of Cell Biology, Faculty of Biology and Environment Protection , Nicolaus Copernicus University , Torun , Poland
| | - Konrad Dełeńko
- a Department of Cell Biology, Faculty of Biology and Environment Protection , Nicolaus Copernicus University , Torun , Poland
| | - Katarzyna Niedojadło
- a Department of Cell Biology, Faculty of Biology and Environment Protection , Nicolaus Copernicus University , Torun , Poland
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31
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Hyjek M, Wojciechowska N, Rudzka M, Kołowerzo-Lubnau A, Smoliński DJ. Spatial regulation of cytoplasmic snRNP assembly at the cellular level. J Exp Bot 2015; 66:7019-30. [PMID: 26320237 PMCID: PMC4765780 DOI: 10.1093/jxb/erv399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Small nuclear ribonucleoproteins (snRNPs) play a crucial role in pre-mRNA splicing in all eukaryotic cells. In contrast to the relatively broad knowledge on snRNP assembly within the nucleus, the spatial organization of the cytoplasmic stages of their maturation remains poorly understood. Nevertheless, sparse research indicates that, similar to the nuclear steps, the crucial processes of cytoplasmic snRNP assembly may also be strictly spatially regulated. In European larch microsporocytes, it was determined that the cytoplasmic assembly of snRNPs within a cell might occur in two distinct spatial manners, which depend on the rate of de novo snRNP formation in relation to the steady state of these particles within the nucleus. During periods of moderate expression of splicing elements, the cytoplasmic assembly of snRNPs occurred diffusely throughout the cytoplasm. Increased expression of both Sm proteins and U snRNA triggered the accumulation of these particles within distinct, non-membranous RNP-rich granules, which are referred to as snRNP-rich cytoplasmic bodies.
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Affiliation(s)
- Malwina Hyjek
- Department of Cell Biology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Lwowska 1, Toruń, 87-100, Poland Centre For Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wileńska 4, 87-100 Toruń Poland
| | - Natalia Wojciechowska
- Department of Cell Biology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Lwowska 1, Toruń, 87-100, Poland Department of General Botany, Institute of Experimental Biology, Faculty of Biology, A. Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Magda Rudzka
- Department of Cell Biology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Lwowska 1, Toruń, 87-100, Poland Centre For Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wileńska 4, 87-100 Toruń Poland
| | - Agnieszka Kołowerzo-Lubnau
- Department of Cell Biology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Lwowska 1, Toruń, 87-100, Poland Centre For Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wileńska 4, 87-100 Toruń Poland
| | - Dariusz Jan Smoliński
- Department of Cell Biology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Lwowska 1, Toruń, 87-100, Poland Centre For Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wileńska 4, 87-100 Toruń Poland
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Simões M, Rino J, Pinheiro I, Martins C, Ferreira F. Alterations of Nuclear Architecture and Epigenetic Signatures during African Swine Fever Virus Infection. Viruses 2015; 7:4978-96. [PMID: 26389938 PMCID: PMC4584302 DOI: 10.3390/v7092858] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 12/11/2022] Open
Abstract
Viral interactions with host nucleus have been thoroughly studied, clarifying molecular mechanisms and providing new antiviral targets. Considering that African swine fever virus (ASFV) intranuclear phase of infection is poorly understood, viral interplay with subnuclear domains and chromatin architecture were addressed. Nuclear speckles, Cajal bodies, and promyelocytic leukaemia nuclear bodies (PML-NBs) were evaluated by immunofluorescence microscopy and Western blot. Further, efficient PML protein knockdown by shRNA lentiviral transduction was used to determine PML-NBs relevance during infection. Nuclear distribution of different histone H3 methylation marks at lysine’s 9, 27 and 36, heterochromatin protein 1 isoforms (HP1α, HPβ and HPγ) and several histone deacetylases (HDACs) were also evaluated to assess chromatin status of the host. Our results reveal morphological disruption of all studied subnuclear domains and severe reduction of viral progeny in PML-knockdown cells. ASFV promotes H3K9me3 and HP1β foci formation from early infection, followed by HP1α and HDAC2 nuclear enrichment, suggesting heterochromatinization of host genome. Finally, closeness between DNA damage response factors, disrupted PML-NBs, and virus-induced heterochromatic regions were identified. In sum, our results demonstrate that ASFV orchestrates spatio-temporal nuclear rearrangements, changing subnuclear domains, relocating Ataxia Telangiectasia Mutated Rad-3 related (ATR)-related factors and promoting heterochromatinization, probably controlling transcription, repressing host gene expression, and favouring viral replication.
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Affiliation(s)
- Margarida Simões
- CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida Universidade Técnica, 1300-477 Lisboa, Portugal.
| | - José Rino
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal.
| | - Inês Pinheiro
- Department of Epigenetics, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany.
| | - Carlos Martins
- CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida Universidade Técnica, 1300-477 Lisboa, Portugal.
| | - Fernando Ferreira
- CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida Universidade Técnica, 1300-477 Lisboa, Portugal.
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Vogan JM, Collins K. Dynamics of Human Telomerase Holoenzyme Assembly and Subunit Exchange across the Cell Cycle. J Biol Chem 2015; 290:21320-35. [PMID: 26170453 DOI: 10.1074/jbc.m115.659359] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Indexed: 01/04/2023] Open
Abstract
Human telomerase acts on telomeres during the genome synthesis phase of the cell cycle, accompanied by its concentration in Cajal bodies and transient colocalization with telomeres. Whether the regulation of human telomerase holoenzyme assembly contributes to the cell cycle restriction of telomerase function is unknown. We investigated the steady-state levels, assembly, and exchange dynamics of human telomerase subunits with quantitative in vivo cross-linking and other methods. We determined the physical association of telomerase subunits in cells blocked or progressing through the cell cycle as synchronized by multiple protocols. The total level of human telomerase RNA (hTR) was invariant across the cell cycle. In vivo snapshots of telomerase holoenzyme composition established that hTR remains bound to human telomerase reverse transcriptase (hTERT) throughout all phases of the cell cycle, and subunit competition assays suggested that hTERT-hTR interaction is not readily exchangeable. In contrast, the telomerase holoenzyme Cajal body-associated protein, TCAB1, was released from hTR in mitotic cells coincident with TCAB1 delocalization from Cajal bodies. This telomerase holoenzyme disassembly was reversible with cell cycle progression without any change in total TCAB1 protein level. Consistent with differential cell cycle regulation of hTERT-hTR and TCAB1-hTR protein-RNA interactions, overexpression of hTERT or TCAB1 had limited if any influence on hTR assembly of the other subunit. Overall, these findings revealed a cell cycle regulation that disables human telomerase association with telomeres while preserving the co-folded hTERT-hTR ribonucleoprotein catalytic core. Studies here, integrated with previous work, led to a unifying model for telomerase subunit assembly and trafficking in human cells.
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Affiliation(s)
- Jacob M Vogan
- From the Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720
| | - Kathleen Collins
- From the Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720
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Rogers S, Gloss BS, Lee CS, Sergio CM, Dinger ME, Musgrove EA, Burgess A, Caldon CE. Cyclin E2 is the predominant E-cyclin associated with NPAT in breast cancer cells. Cell Div 2015; 10:1. [PMID: 25741376 PMCID: PMC4349318 DOI: 10.1186/s13008-015-0007-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 02/02/2015] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The cyclin E oncogene activates CDK2 to drive cells from G1 to S phase of the cell cycle to commence DNA replication. It coordinates essential cellular functions with the cell cycle including histone biogenesis, splicing, centrosome duplication and origin firing for DNA replication. The two E-cyclins, E1 and E2, are assumed to act interchangeably in these functions. However recent reports have identified unique functions for cyclins E1 and E2 in different tissues, and particularly in breast cancer. FINDINGS Cyclins E1 and E2 localise to distinct foci in breast cancer cells as well as co-localising within the cell. Both E-cyclins are found in complex with CDK2, at centrosomes and with the splicing machinery in nuclear speckles. However cyclin E2 uniquely co-localises with NPAT, the main activator of cell-cycle regulated histone transcription. Increased cyclin E2, but not cyclin E1, expression is associated with high expression of replication-dependent histones in breast cancers. CONCLUSIONS The preferential localisation of cyclin E1 or cyclin E2 to distinct foci indicates that each E-cyclin has unique roles. Cyclin E2 uniquely interacts with NPAT in breast cancer cells, and is associated with higher levels of histones in breast cancer. This could explain the unique correlations of high cyclin E2 expression with poor outcome and genomic instability in breast cancer.
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Affiliation(s)
- Samuel Rogers
- />The Kinghorn Cancer Centre and Cancer Research Program, Garvan Institute of Medical Research, Sydney, NSW Australia
| | - Brian S Gloss
- />The Kinghorn Cancer Centre and Cancer Research Program, Garvan Institute of Medical Research, Sydney, NSW Australia
- />St Vincent’s Clinical School, Faculty of Medicine UNSW, Sydney, Australia
| | - Christine S Lee
- />The Kinghorn Cancer Centre and Cancer Research Program, Garvan Institute of Medical Research, Sydney, NSW Australia
| | - Claudio Marcelo Sergio
- />The Kinghorn Cancer Centre and Cancer Research Program, Garvan Institute of Medical Research, Sydney, NSW Australia
| | - Marcel E Dinger
- />The Kinghorn Cancer Centre and Cancer Research Program, Garvan Institute of Medical Research, Sydney, NSW Australia
- />St Vincent’s Clinical School, Faculty of Medicine UNSW, Sydney, Australia
| | - Elizabeth A Musgrove
- />Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Glasgow, G61 1QH UK
| | - Andrew Burgess
- />The Kinghorn Cancer Centre and Cancer Research Program, Garvan Institute of Medical Research, Sydney, NSW Australia
- />St Vincent’s Clinical School, Faculty of Medicine UNSW, Sydney, Australia
| | - Catherine Elizabeth Caldon
- />The Kinghorn Cancer Centre and Cancer Research Program, Garvan Institute of Medical Research, Sydney, NSW Australia
- />St Vincent’s Clinical School, Faculty of Medicine UNSW, Sydney, Australia
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Abstract
The nuclear SMN complex localizes to specific structures called nuclear gems. The loss of gems is a cellular marker for several neurodegenerative diseases. Here, we identify that the U1-snRNP-specific protein U1-70K localizes to nuclear gems, and we show that U1-70K is necessary for gem integrity. Furthermore, we show that the interaction between U1-70K and the SMN complex is RNA independent, and we map the SMN complex binding site to the unstructured N-terminal tail of U1-70K. Consistent with these results, the expression of the U1-70K N-terminal tail rescues gem formation. These findings show that U1-70K is an SMN-complex-associating protein, and they suggest a new function for U1-70K in the formation of nuclear gems.
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Affiliation(s)
- Eva Stejskalová
- Department of RNA Biology, Institute of Molecular Genetics AS CR, 142 20 Prague, Czech Republic Faculty of Science, Charles University in Prague, 128 43 Prague, Czech Republic
| | - David Staněk
- Department of RNA Biology, Institute of Molecular Genetics AS CR, 142 20 Prague, Czech Republic
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Bártová E, Foltánková V, Legartová S, Sehnalová P, Sorokin DV, Suchánková J, Kozubek S. Coilin is rapidly recruited to UVA-induced DNA lesions and γ-radiation affects localized movement of Cajal bodies. Nucleus 2014; 5:460-8. [PMID: 24859326 DOI: 10.4161/nucl.29229] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cajal bodies are important nuclear structures containing proteins that preferentially regulate RNA-related metabolism. We investigated the cell-type specific nuclear distribution of Cajal bodies and the level of coilin, a protein of Cajal bodies, in non-irradiated and irradiated human tumor cell lines and embryonic stem (ES) cells. Cajal bodies were localized in different nuclear compartments, including DAPI-poor regions, in the proximity of chromocenters, and adjacent to nucleoli. The number of Cajal bodies per nucleus was cell cycle-dependent, with higher numbers occurring during G2 phase. Human ES cells contained a high coilin level in the nucleoplasm, but coilin-positive Cajal bodies were also identified in nuclei of mouse and human ES cells. Coilin, but not SMN, recognized UVA-induced DNA lesions, which was cell cycle-independent. Treatment with γ-radiation reduced the localized movement of Cajal bodies in many cell types and GFP-coilin fluorescence recovery after photobleaching was very fast in nucleoplasm in comparison with GFP-coilin recovery in DNA lesions. By contrast, nucleolus-localized coilin displayed very slow fluorescence recovery after photobleaching, which indicates very slow rates of protein diffusion, especially in nucleoli of mouse ES cells.
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Affiliation(s)
- Eva Bártová
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Veronika Foltánková
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Soňa Legartová
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Petra Sehnalová
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Dmitry V Sorokin
- Faculty of Informatics; Masaryk University; Brno, Czech Republic
| | - Jana Suchánková
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Stanislav Kozubek
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
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Shaw J, Love AJ, Makarova SS, Kalinina NO, Harrison BD, Taliansky ME. Coilin, the signature protein of Cajal bodies, differentially modulates the interactions of plants with viruses in widely different taxa. Nucleus 2014; 5:85-94. [PMID: 24637832 PMCID: PMC4028359 DOI: 10.4161/nucl.28315] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 02/18/2014] [Accepted: 02/21/2014] [Indexed: 12/28/2022] Open
Abstract
Cajal bodies (CBs) are distinct nuclear bodies physically and functionally associated with the nucleolus. In addition to their traditional function in coordinating maturation of certain nuclear RNAs, CBs participate in cell cycle regulation, development, and regulation of stress responses. A key "signature" component of CBs is coilin, the scaffolding protein essential for CB formation and function. Using an RNA silencing (loss-of-function) approach, we describe here new phenomena whereby coilin also affects, directly or indirectly, a variety of interactions between host plants and viruses that have RNA or DNA genomes. Moreover, the effects of coilin on these interactions are manifested differently: coilin contributes to plant defense against tobacco rattle virus (tobravirus), tomato black ring virus (nepovirus), barley stripe mosaic virus (hordeivirus), and tomato golden mosaic virus (begomovirus). In contrast, with potato virus Y (potyvirus) and turnip vein clearing virus (tobamovirus), coilin serves to increase virus pathogenicity. These findings show that interactions with coilin (or CBs) may involve diverse mechanisms with different viruses and that these mechanisms act at different phases of virus infection. Thus, coilin (CBs) has novel, unexpected natural functions that may be recruited or subverted by plant viruses for their own needs or, in contrast, are involved in plant defense mechanisms that suppress host susceptibility to the viruses.
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Affiliation(s)
- Jane Shaw
- Cell and Molecular Sciences; The James Hutton Institute; Dundee, UK
| | - Andrew J Love
- Cell and Molecular Sciences; The James Hutton Institute; Dundee, UK
| | - Svetlana S Makarova
- AN Belozersky Institute of Physico-Chemical Biology; Moscow State University; Moscow, Russia
| | - Natalia O Kalinina
- AN Belozersky Institute of Physico-Chemical Biology; Moscow State University; Moscow, Russia
| | - Bryan D Harrison
- Cell and Molecular Sciences; The James Hutton Institute; Dundee, UK
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Bogolyubov DS, Batalova FM, Kiselyov AM, Stepanova IS. Nuclear structures in Tribolium castaneum oocytes. Cell Biol Int 2013; 37:1061-79. [PMID: 23686847 DOI: 10.1002/cbin.10135] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 04/21/2013] [Indexed: 12/12/2022]
Abstract
The first ultrastructural and immunomorphological characteristics of the karyosphere (karyosome) and extrachromosomal nuclear bodies in the red flour beetle, Tribolium castaneum, are presented. The karyosphere forms early in the diplotene stage of meiotic prophase by the gathering of all oocyte chromosomes in a limited nuclear volume. Using the BrUTP assay, T. castaneum oocyte chromosomes united in the karyosphere maintain their transcriptional activity until the end of oocyte growth. Hyperphosphorylated RNA polymerase II and basal transcription factors (TFIID and TFIIH) were detected in the perichromatin region of the karyosphere. The T. castaneum karyosphere has an extrachromosomal capsule that separates chromosomes from the rest of the nucleoplasm. Certain structural proteins (F-actin, lamin B) were found in the capsule. Unexpectedly, the karyosphere capsule in T. castaneum oocytes was found to be enriched in TMG-capped snRNAs, which suggests that the capsule is not only a structural support for the karyosphere, but may be involved in biogenesis of snRNPs. We also identified the counterparts of 'universal' extrachromosomal nuclear domains, Cajal bodies (CBs) and interchromatin granule clusters (IGCs). Nuclear bodies containing IGC marker protein SC35 display some features unusual for typical IGCs. SC35 domains in T. castaneum oocytes are predominantly fibrillar complex bodies that do not contain trimethyl guanosine (TMG)-capped small nuclear (sn) RNAs. Microinjections of 2'-O-methyl (U)22 probes into the oocytes allowed revealing poly(A)+ RNAs in these nuclear domains. Several proteins related to mRNA export (heterogeneous ribonucleoprotein core protein A1, export adapters Y14 and Aly and export receptor NXF1) were also detected there. We believe that unusual SC35 nuclear domains of T. castaneum oocytes are possibly involved in mRNP but not snRNP biogenesis.
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Affiliation(s)
- Dmitry S Bogolyubov
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russia.
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