1
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Fritz AJ, Ghule PN, Toor R, Dillac L, Perelman J, Boyd J, Lian JB, Gordon JA, Frietze S, Van Wijnen A, Stein JL, Stein GS. Spatiotemporal Epigenetic Control of the Histone Gene Chromatin Landscape during the Cell Cycle. Crit Rev Eukaryot Gene Expr 2023; 33:85-97. [PMID: 37017672 PMCID: PMC10826887 DOI: 10.1615/critreveukaryotgeneexpr.2022046190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Higher-order genomic organization supports the activation of histone genes in response to cell cycle regulatory cues that epigenetically mediates stringent control of transcription at the G1/S-phase transition. Histone locus bodies (HLBs) are dynamic, non-membranous, phase-separated nuclear domains where the regulatory machinery for histone gene expression is organized and assembled to support spatiotemporal epigenetic control of histone genes. HLBs provide molecular hubs that support synthesis and processing of DNA replication-dependent histone mRNAs. These regulatory microenvironments support long-range genomic interactions among non-contiguous histone genes within a single topologically associating domain (TAD). HLBs respond to activation of the cyclin E/CDK2/NPAT/HINFP pathway at the G1/S transition. HINFP and its coactivator NPAT form a complex within HLBs that controls histone mRNA transcription to support histone protein synthesis and packaging of newly replicated DNA. Loss of HINFP compromises H4 gene expression and chromatin formation, which may result in DNA damage and impede cell cycle progression. HLBs provide a paradigm for higher-order genomic organization of a subnuclear domain that executes an obligatory cell cycle-controlled function in response to cyclin E/CDK2 signaling. Understanding the coordinately and spatiotemporally organized regulatory programs in focally defined nuclear domains provides insight into molecular infrastructure for responsiveness to cell signaling pathways that mediate biological control of growth, differentiation phenotype, and are compromised in cancer.
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Affiliation(s)
- Andrew J. Fritz
- Department of Biochemistry, University of Vermont, Burlington, Vermont, USA
- University of Vermont Cancer Center, Burlington, Vermont, USA
| | - Prachi N. Ghule
- Department of Biochemistry, University of Vermont, Burlington, Vermont, USA
- University of Vermont Cancer Center, Burlington, Vermont, USA
| | - Rabail Toor
- Department of Biochemistry, University of Vermont, Burlington, Vermont, USA
- University of Vermont Cancer Center, Burlington, Vermont, USA
| | - Louis Dillac
- Department of Biochemistry, University of Vermont, Burlington, Vermont, USA
- University of Vermont Cancer Center, Burlington, Vermont, USA
| | - Jonah Perelman
- Department of Biochemistry, University of Vermont, Burlington, Vermont, USA
| | - Joseph Boyd
- College of Nursing and Health Sciences, University of Vermont, Burlington, Vermont, USA
| | - Jane B. Lian
- Department of Biochemistry, University of Vermont, Burlington, Vermont, USA
- University of Vermont Cancer Center, Burlington, Vermont, USA
| | - Johnathan A.R. Gordon
- Department of Biochemistry, University of Vermont, Burlington, Vermont, USA
- University of Vermont Cancer Center, Burlington, Vermont, USA
| | - Seth Frietze
- University of Vermont Cancer Center, Burlington, Vermont, USA
- College of Nursing and Health Sciences, University of Vermont, Burlington, Vermont, USA
| | - Andre Van Wijnen
- Department of Biochemistry, University of Vermont, Burlington, Vermont, USA
| | - Janet L. Stein
- Department of Biochemistry, University of Vermont, Burlington, Vermont, USA
- University of Vermont Cancer Center, Burlington, Vermont, USA
| | - Gary S. Stein
- Department of Biochemistry, University of Vermont, Burlington, Vermont, USA
- University of Vermont Cancer Center, Burlington, Vermont, USA
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2
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Direct imaging of intracellular RNA, DNA, and liquid-liquid phase separated membraneless organelles with Raman microspectroscopy. Commun Biol 2022; 5:1383. [PMID: 36528668 PMCID: PMC9759543 DOI: 10.1038/s42003-022-04342-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
Methodologies for direct intracellular imaging of RNA and DNA are necessary for the advancement of bioimaging. Here we show direct label-free imaging of RNA and DNA in single cells by isolating their accurate Raman spectra. Raman images of DNA from interphase cells show intact nucleus, while those from mitotic cells reveal condensed chromosome. The condensed chromosome images are accurate enough to assign the stage of mitotic cell division (e.g., metaphase). Raman spectral features indicate B-DNA double helical conformational form in all the cell lines investigated here. The Raman images of RNAs, on the other hand, reveal liquid-liquid phase separated (LLPS) membraneless organelles in interphase cells, which disappears during mitosis. Further, the Raman spectrum of proteins from the intracellular LLPS organelles indicates slight enrichment of amyloid-like secondary structural features. Vibrational imaging of intracellular DNA and RNA simultaneously would open myriad of opportunities for examining functional biochemical aspects of cells and organelles.
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3
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Fritz AJ, El Dika M, Toor RH, Rodriguez PD, Foley SJ, Ullah R, Nie D, Banerjee B, Lohese D, Glass KC, Frietze S, Ghule PN, Heath JL, Imbalzano AN, van Wijnen A, Gordon J, Lian JB, Stein JL, Stein GS, Stein GS. Epigenetic-Mediated Regulation of Gene Expression for Biological Control and Cancer: Cell and Tissue Structure, Function, and Phenotype. Results Probl Cell Differ 2022; 70:339-373. [PMID: 36348114 PMCID: PMC9753575 DOI: 10.1007/978-3-031-06573-6_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Epigenetic gene regulatory mechanisms play a central role in the biological control of cell and tissue structure, function, and phenotype. Identification of epigenetic dysregulation in cancer provides mechanistic into tumor initiation and progression and may prove valuable for a variety of clinical applications. We present an overview of epigenetically driven mechanisms that are obligatory for physiological regulation and parameters of epigenetic control that are modified in tumor cells. The interrelationship between nuclear structure and function is not mutually exclusive but synergistic. We explore concepts influencing the maintenance of chromatin structures, including phase separation, recognition signals, factors that mediate enhancer-promoter looping, and insulation and how these are altered during the cell cycle and in cancer. Understanding how these processes are altered in cancer provides a potential for advancing capabilities for the diagnosis and identification of novel therapeutic targets.
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Affiliation(s)
- Andrew J. Fritz
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Mohammed El Dika
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Rabail H. Toor
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | | | - Stephen J. Foley
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Rahim Ullah
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Daijing Nie
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Bodhisattwa Banerjee
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Dorcas Lohese
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Karen C. Glass
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Pharmacology, Burlington, VT 05405
| | - Seth Frietze
- University of Vermont, College of Nursing and Health Sciences, Burlington, VT 05405
| | - Prachi N. Ghule
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Jessica L. Heath
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405,University of Vermont, Larner College of Medicine, Department of Pediatrics, Burlington, VT 05405
| | - Anthony N. Imbalzano
- UMass Chan Medical School, Department of Biochemistry and Molecular Biotechnology, Worcester, MA 01605
| | - Andre van Wijnen
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Jonathan Gordon
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Jane B. Lian
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Janet L. Stein
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Gary S. Stein
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
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4
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Phasing the intranuclear organization of steroid hormone receptors. Biochem J 2021; 478:443-461. [DOI: 10.1042/bcj20200883] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/28/2020] [Accepted: 01/07/2021] [Indexed: 12/15/2022]
Abstract
Steroid receptors (SRs) encompass a family of transcription factors that regulate the expression of thousands of genes upon binding to steroid hormones and include the glucocorticoid, androgen, progesterone, estrogen and mineralocorticoid receptors. SRs control key physiological and pathological processes, thus becoming relevant drug targets. As with many other nuclear proteins, hormone-activated SRs concentrate in multiple discrete foci within the cell nucleus. Even though these foci were first observed ∼25 years ago, their exact structure and function remained elusive. In the last years, new imaging methodologies and theoretical frameworks improved our understanding of the intranuclear organization. These studies led to a new paradigm stating that many membraneless nuclear compartments, including transcription-related foci, form through a liquid–liquid phase separation process. These exciting ideas impacted the SR field by raising the hypothesis of SR foci as liquid condensates involved in transcriptional regulation. In this work, we review the current knowledge about SR foci formation under the light of the condensate model, analyzing how these structures may impact SR function. These new ideas, combined with state-of-the-art techniques, may shed light on the biophysical mechanisms governing the formation of SR foci and the biological function of these structures in normal physiology and disease.
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5
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Rensen E, Mueller F, Scoca V, Parmar JJ, Souque P, Zimmer C, Di Nunzio F. Clustering and reverse transcription of HIV-1 genomes in nuclear niches of macrophages. EMBO J 2021; 40:e105247. [PMID: 33270250 PMCID: PMC7780146 DOI: 10.15252/embj.2020105247] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 10/04/2020] [Accepted: 10/16/2020] [Indexed: 01/07/2023] Open
Abstract
In order to replicate, human immunodeficiency virus (HIV-1) reverse-transcribes its RNA genome into DNA, which subsequently integrates into host cell chromosomes. These two key events of the viral life cycle are commonly viewed as separate not only in time, but also in cellular space, since reverse transcription (RT) is thought to be completed in the cytoplasm before nuclear import and integration. However, the spatiotemporal organization of the early viral replication cycle in macrophages, the natural non-dividing target cells that constitute reservoirs of HIV-1 and an obstacle to curing AIDS, remains unclear. Here, we demonstrate that infected macrophages display large nuclear foci of viral DNA (vDNA) and viral RNA, in which multiple viral genomes cluster together. These clusters form in the absence of chromosomal integration, sequester the paraspeckle protein CPSF6, and localize to nuclear speckles. Surprisingly, these viral RNA clusters consist mostly of genomic, incoming RNA, both in cells where reverse transcription is pharmacologically suppressed and in untreated cells. We demonstrate that following temporary inhibition, reverse transcription can resume in the nucleus and lead to vDNA accumulation in these clusters. We further show that nuclear reverse transcription can result in transcription-competent viral DNA. These findings change our understanding of the early HIV-1 replication cycle and may have implications for addressing HIV-1 persistence.
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Affiliation(s)
- Elena Rensen
- Imaging and Modeling UnitInstitut PasteurUMR 3691 CNRSC3BI USR 3756 IP CNRSParisFrance
- Molecular Virology and VaccinologyInstitut PasteurParisFrance
| | - Florian Mueller
- Imaging and Modeling UnitInstitut PasteurUMR 3691 CNRSC3BI USR 3756 IP CNRSParisFrance
| | - Viviana Scoca
- Molecular Virology and VaccinologyInstitut PasteurParisFrance
| | - Jyotsana J Parmar
- Imaging and Modeling UnitInstitut PasteurUMR 3691 CNRSC3BI USR 3756 IP CNRSParisFrance
| | - Philippe Souque
- Molecular Virology and VaccinologyInstitut PasteurParisFrance
| | - Christophe Zimmer
- Imaging and Modeling UnitInstitut PasteurUMR 3691 CNRSC3BI USR 3756 IP CNRSParisFrance
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6
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Chen ZH, Chen TQ, Zeng ZC, Wang D, Han C, Sun YM, Huang W, Sun LY, Fang K, Chen YQ, Luo XQ, Wang WT. Nuclear export of chimeric mRNAs depends on an lncRNA-triggered autoregulatory loop in blood malignancies. Cell Death Dis 2020; 11:566. [PMID: 32703936 PMCID: PMC7378249 DOI: 10.1038/s41419-020-02795-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 07/05/2020] [Accepted: 07/09/2020] [Indexed: 12/16/2022]
Abstract
Aberrant chromosomal translocations leading to tumorigenesis have been ascribed to the heterogeneously oncogenic functions. However, how fusion transcripts exporting remains to be declared. Here, we showed that the nuclear speckle-specific long noncoding RNA MALAT1 controls chimeric mRNA export processes and regulates myeloid progenitor cell differentiation in malignant hematopoiesis. We demonstrated that MALAT1 regulates chimeric mRNAs export in an m6A-dependent manner and thus controls hematopoietic cell differentiation. Specifically, reducing MALAT1 or m6A methyltransferases and the 'reader' YTHDC1 result in the universal retention of distinct oncogenic gene mRNAs in nucleus. Mechanically, MALAT1 hijacks both the chimeric mRNAs and fusion proteins in nuclear speckles during chromosomal translocations and mediates the colocalization of oncogenic fusion proteins with METTL14. MALAT1 and fusion protein complexes serve as a functional loading bridge for the interaction of chimeric mRNA and METTL14. This study demonstrated a universal mechanism of chimeric mRNA transport that involves lncRNA-fusion protein-m6A autoregulatory loop for controlling myeloid cell differentiation. Targeting the lncRNA-triggered autoregulatory loop to disrupt chimeric mRNA transport might represent a new common paradigm for treating blood malignancies.
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Affiliation(s)
- Zhen-Hua Chen
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Tian-Qi Chen
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Zhan-Cheng Zeng
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Dan Wang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, 510060, Guangzhou, Guangdong, China
| | - Cai Han
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Yu-Meng Sun
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Wei Huang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Lin-Yu Sun
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Ke Fang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Yue-Qin Chen
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Xue-Qun Luo
- The First Affiliated Hospital, Sun Yat-sen University, 510080, Guangzhou, China
| | - Wen-Tao Wang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China.
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7
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Parmar JJ, Woringer M, Zimmer C. How the Genome Folds: The Biophysics of Four-Dimensional Chromatin Organization. Annu Rev Biophys 2019; 48:231-253. [DOI: 10.1146/annurev-biophys-052118-115638] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The genetic information that instructs transcription and other cellular functions is carried by the chromosomes, polymers of DNA in complex with histones and other proteins. These polymers are folded inside nuclei five orders of magnitude smaller than their linear length, and many facets of this folding correlate with or are causally related to transcription and other cellular functions. Recent advances in sequencing and imaging-based techniques have enabled new views into several layers of chromatin organization. These experimental findings are accompanied by computational modeling efforts based on polymer physics that can provide mechanistic insights and quantitative predictions. Here, we review current knowledge of the main levels of chromatin organization, from the scale of nucleosomes to the entire nucleus, our current understanding of their underlying biophysical and molecular mechanisms, and some of their functional implications.
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Affiliation(s)
- Jyotsana J. Parmar
- Unité Imagerie et Modélisation, CNRS UMR 3691, and C3BI (Center of Bioinformatics, Biostatistics and Integrative Biology), CNRS USR 3756, Institut Pasteur, 75015 Paris, France;, ,
| | - Maxime Woringer
- Unité Imagerie et Modélisation, CNRS UMR 3691, and C3BI (Center of Bioinformatics, Biostatistics and Integrative Biology), CNRS USR 3756, Institut Pasteur, 75015 Paris, France;, ,
- Sorbonne Universités, CNRS, 75005 Paris, France
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, and CIRM Center of Excellence in Stem Cell Genomics, University of California, Berkeley, California 94720, USA
| | - Christophe Zimmer
- Unité Imagerie et Modélisation, CNRS UMR 3691, and C3BI (Center of Bioinformatics, Biostatistics and Integrative Biology), CNRS USR 3756, Institut Pasteur, 75015 Paris, France;, ,
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8
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Verdile V, De Paola E, Paronetto MP. Aberrant Phase Transitions: Side Effects and Novel Therapeutic Strategies in Human Disease. Front Genet 2019; 10:173. [PMID: 30967892 PMCID: PMC6440380 DOI: 10.3389/fgene.2019.00173] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 02/18/2019] [Indexed: 12/12/2022] Open
Abstract
Phase separation is a physiological process occurring spontaneously when single-phase molecular complexes separate in two phases, a concentrated phase and a more diluted one. Eukaryotic cells employ phase transition strategies to promote the formation of intracellular territories not delimited by membranes with increased local RNA concentration, such as nucleolus, paraspeckles, P granules, Cajal bodies, P-bodies, and stress granules. These organelles contain both proteins and coding and non-coding RNAs and play important roles in different steps of the regulation of gene expression and in cellular signaling. Recently, it has been shown that most human RNA-binding proteins (RBPs) contain at least one low-complexity domain, called prion-like domain (PrLD), because proteins harboring them display aggregation properties like prion proteins. PrLDs support RBP function and contribute to liquid–liquid phase transitions that drive ribonucleoprotein granule assembly, but also render RBPs prone to misfolding by promoting the formation of pathological aggregates that lead to toxicity in specific cell types. Protein–protein and protein-RNA interactions within the separated phase can enhance the transition of RBPs into solid aberrant aggregates, thus causing diseases. In this review, we highlight the role of phase transition in human disease such as amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and in cancer. Moreover, we discuss novel therapeutic strategies focused to control phase transitions by preventing the conversion into aberrant aggregates. In this regard, the stimulation of chaperone machinery to disassemble membrane-less organelles, the induction of pathways that could inhibit aberrant phase separation, and the development of antisense oligonucleotides (ASOs) to knockdown RNAs could be evaluated as novel therapeutic strategies for the treatment of those human diseases characterized by aberrant phase transition aggregates.
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Affiliation(s)
- Veronica Verdile
- University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, Fondazione Santa Lucia, Rome, Italy
| | - Elisa De Paola
- University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, Fondazione Santa Lucia, Rome, Italy
| | - Maria Paola Paronetto
- University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, Fondazione Santa Lucia, Rome, Italy
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9
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Fritz AJ, Gillis NE, Gerrard DL, Rodriguez PD, Hong D, Rose JT, Ghule PN, Bolf EL, Gordon JA, Tye CE, Boyd JR, Tracy KM, Nickerson JA, van Wijnen AJ, Imbalzano AN, Heath JL, Frietze SE, Zaidi SK, Carr FE, Lian JB, Stein JL, Stein GS. Higher order genomic organization and epigenetic control maintain cellular identity and prevent breast cancer. Genes Chromosomes Cancer 2019; 58:484-499. [PMID: 30873710 DOI: 10.1002/gcc.22731] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/07/2019] [Accepted: 01/07/2019] [Indexed: 12/24/2022] Open
Abstract
Cells establish and sustain structural and functional integrity of the genome to support cellular identity and prevent malignant transformation. In this review, we present a strategic overview of epigenetic regulatory mechanisms including histone modifications and higher order chromatin organization (HCO) that are perturbed in breast cancer onset and progression. Implications for dysfunctions that occur in hormone regulation, cell cycle control, and mitotic bookmarking in breast cancer are considered, with an emphasis on epithelial-to-mesenchymal transition and cancer stem cell activities. The architectural organization of regulatory machinery is addressed within the contexts of translating cancer-compromised genomic organization to advances in breast cancer risk assessment, diagnosis, prognosis, and identification of novel therapeutic targets with high specificity and minimal off target effects.
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Affiliation(s)
- A J Fritz
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont
| | - N E Gillis
- University of Vermont Cancer Center, Burlington, Vermont.,Department of Pharmacology, Larner college of Medicine, University of Vermont, Burlington, Vermont
| | - D L Gerrard
- Cellular Molecular Biomedical Sciences Program, University of Vermont, Burlington, Vermont.,Department of Biomedical and Health Sciences, University of Vermont, Burlington, Vermont
| | - P D Rodriguez
- Cellular Molecular Biomedical Sciences Program, University of Vermont, Burlington, Vermont.,Department of Biomedical and Health Sciences, University of Vermont, Burlington, Vermont
| | - D Hong
- Department of Medical Oncology, Dana Farber Cancer Institute, Boston, Massachusetts
| | - J T Rose
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont
| | - P N Ghule
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont
| | - E L Bolf
- University of Vermont Cancer Center, Burlington, Vermont.,Department of Pharmacology, Larner college of Medicine, University of Vermont, Burlington, Vermont
| | - J A Gordon
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont
| | - C E Tye
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont
| | - J R Boyd
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont
| | - K M Tracy
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont
| | - J A Nickerson
- Division of Genes and Development of the Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts
| | - A J van Wijnen
- Orthopedic Surgery and Biochemistry and Molecular Biology, Mayo Clinic Minnesota, Rochester, Minnesota
| | - A N Imbalzano
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - J L Heath
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont.,Department of Pediatrics, Larner College of Medicine, University of Vermont, Burlington, Vermont
| | - S E Frietze
- Cellular Molecular Biomedical Sciences Program, University of Vermont, Burlington, Vermont.,Department of Biomedical and Health Sciences, University of Vermont, Burlington, Vermont
| | - S K Zaidi
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont
| | - F E Carr
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont.,Department of Pharmacology, Larner college of Medicine, University of Vermont, Burlington, Vermont
| | - J B Lian
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont
| | - J L Stein
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont
| | - G S Stein
- Department of Biochemistry, Larner College of Medicine, University of Vermont, Burlington, Vermont.,University of Vermont Cancer Center, Burlington, Vermont
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10
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Sawyer IA, Hager GL, Dundr M. Specific genomic cues regulate Cajal body assembly. RNA Biol 2017; 14:791-803. [PMID: 27715441 PMCID: PMC5519236 DOI: 10.1080/15476286.2016.1243648] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/06/2016] [Accepted: 09/27/2016] [Indexed: 02/07/2023] Open
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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11
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Neural Differentiation in HDAC1-Depleted Cells Is Accompanied by Coilin Downregulation and the Accumulation of Cajal Bodies in Nucleoli. Stem Cells Int 2017; 2017:1021240. [PMID: 28337219 PMCID: PMC5350323 DOI: 10.1155/2017/1021240] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 01/12/2017] [Accepted: 01/26/2017] [Indexed: 12/23/2022] Open
Abstract
Cajal bodies (CBs) are important compartments containing accumulated proteins that preferentially regulate RNA-related nuclear events, including splicing. Here, we studied the nuclear distribution pattern of CBs in neurogenesis. In adult brains, coilin was present at a high density, but CB formation was absent in the nuclei of the choroid plexus of the lateral ventricles. Cells of the adult hippocampus were characterized by a crescent-like morphology of coilin protein. We additionally observed a 70 kDa splice variant of coilin in adult mouse brains, which was different to embryonic brains and mouse pluripotent embryonic stem cells (mESCs), characterized by the 80 kDa standard variant of coilin. Here, we also showed that depletion of coilin is induced during neural differentiation and HDAC1 deficiency in mESCs caused coilin accumulation inside the fibrillarin-positive region of the nucleoli. A similar distribution pattern was observed in adult brain hippocampi, characterized by lower levels of both coilin and HDAC1. In summary, we observed that neural differentiation and HDAC1 deficiency lead to coilin depletion and coilin accumulation in body-like structures inside the nucleoli.
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Development of a pipeline for automated, high-throughput analysis of paraspeckle proteins reveals specific roles for importin α proteins. Sci Rep 2017; 7:43323. [PMID: 28240251 DOI: 10.1038/srep43323] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 01/20/2017] [Indexed: 12/23/2022] Open
Abstract
We developed a large-scale, unbiased analysis method to measure how functional variations in importin (IMP) α2, IMPα4 and IMPα6 each influence PSPC1 and SFPQ nuclear accumulation and their localization to paraspeckles. This addresses the hypothesis that individual IMP protein activities determine cargo nuclear access to influence cell fate outcomes. We previously demonstrated that modulating IMPα2 levels alters paraspeckle protein 1 (PSPC1) nuclear accumulation and affects its localization into a subnuclear domain that affects RNA metabolism and cell survival, the paraspeckle. An automated, high throughput, image analysis pipeline with customisable outputs was created using Imaris software coupled with Python and R scripts; this allowed non-subjective identification of nuclear foci, nuclei and cells. HeLa cells transfected to express exogenous full-length and transport-deficient IMPs were examined using SFPQ and PSPC1 as paraspeckle markers. Thousands of cells and >100,000 nuclear foci were analysed in samples with modulated IMPα functionality. This analysis scale enabled discrimination of significant differences between samples where paraspeckles inherently display broad biological variability. The relative abundance of paraspeckle cargo protein(s) and individual IMPs each influenced nuclear foci numbers and size. This method provides a generalizable high throughput analysis platform for investigating how regulated nuclear protein transport controls cellular activities.
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Sawyer IA, Sturgill D, Sung MH, Hager GL, Dundr M. Cajal body function in genome organization and transcriptome diversity. Bioessays 2016; 38:1197-1208. [PMID: 27767214 DOI: 10.1002/bies.201600144] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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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Trinkle-Mulcahy L, Sleeman JE. The Cajal body and the nucleolus: "In a relationship" or "It's complicated"? RNA Biol 2016; 14:739-751. [PMID: 27661468 DOI: 10.1080/15476286.2016.1236169] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
From their initial identification as 'nucleolar accessory bodies' more than a century ago, the relationship between Cajal bodies and nucleoli has been a subject of interest and controversy. In this review, we seek to place recent developments in the understanding of the physical and functional relationships between the 2 structures in the context of historical observations. Biophysical models of nuclear body formation, the molecular nature of CB/nucleolus interactions and the increasing list of joint roles for CBs and nucleoli, predominantly in assembling ribonucleoprotein (RNP) complexes, are discussed.
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Affiliation(s)
- Laura Trinkle-Mulcahy
- a Department of Cellular and Molecular Medicine , Ottawa Institute of Systems Biology, University of Ottawa , Ottawa , ON , Canada
| | - Judith E Sleeman
- b BSRC Complex, School of Biology, University of St Andrews , UK
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15
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Terzo EA, Lyons SM, Poulton JS, Temple BRS, Marzluff WF, Duronio RJ. Distinct self-interaction domains promote Multi Sex Combs accumulation in and formation of the Drosophila histone locus body. Mol Biol Cell 2015; 26:1559-74. [PMID: 25694448 PMCID: PMC4395134 DOI: 10.1091/mbc.e14-10-1445] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 02/12/2015] [Indexed: 11/11/2022] Open
Abstract
The Drosophila Multi Sex Combs (Mxc) protein is necessary for the recruitment of histone mRNA biosynthetic factors to the histone locus body (HLB). Mxc contains multiple domains required for HLB assembly and histone mRNA biosynthesis. Two N-terminal domains of Mxc are essential for promoting HLB assembly via a self-interaction. Nuclear bodies (NBs) are structures that concentrate proteins, RNAs, and ribonucleoproteins that perform functions essential to gene expression. How NBs assemble is not well understood. We studied the Drosophila histone locus body (HLB), a NB that concentrates factors required for histone mRNA biosynthesis at the replication-dependent histone gene locus. We coupled biochemical analysis with confocal imaging of both fixed and live tissues to demonstrate that the Drosophila Multi Sex Combs (Mxc) protein contains multiple domains necessary for HLB assembly. An important feature of this assembly process is the self-interaction of Mxc via two conserved N-terminal domains: a LisH domain and a novel self-interaction facilitator (SIF) domain immediately downstream of the LisH domain. Molecular modeling suggests that the LisH and SIF domains directly interact, and mutation of either the LisH or the SIF domain severely impairs Mxc function in vivo, resulting in reduced histone mRNA accumulation. A region of Mxc between amino acids 721 and 1481 is also necessary for HLB assembly independent of the LisH and SIF domains. Finally, the C-terminal 195 amino acids of Mxc are required for recruiting FLASH, an essential histone mRNA-processing factor, to the HLB. We conclude that multiple domains of the Mxc protein promote HLB assembly in order to concentrate factors required for histone mRNA biosynthesis.
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Affiliation(s)
- Esteban A Terzo
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599
| | - Shawn M Lyons
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599
| | - John S Poulton
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599
| | - Brenda R S Temple
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599
| | - William F Marzluff
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599 Department of Biology, University of North Carolina, Chapel Hill, NC 27599 Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599 Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599 Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599
| | - Robert J Duronio
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599 Department of Biology, University of North Carolina, Chapel Hill, NC 27599 Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599 Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599 Department of Genetics, University of North Carolina, Chapel Hill, NC 27599
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16
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Bártová E, Foltánková V, Legartová S, Sehnalová P, Sorokin DV, Suchánková J, Kozubek S. Coilin is rapidly recruited to UVA-induced DNA lesions and γ-radiation affects localized movement of Cajal bodies. Nucleus 2014; 5:460-8. [PMID: 24859326 DOI: 10.4161/nucl.29229] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cajal bodies are important nuclear structures containing proteins that preferentially regulate RNA-related metabolism. We investigated the cell-type specific nuclear distribution of Cajal bodies and the level of coilin, a protein of Cajal bodies, in non-irradiated and irradiated human tumor cell lines and embryonic stem (ES) cells. Cajal bodies were localized in different nuclear compartments, including DAPI-poor regions, in the proximity of chromocenters, and adjacent to nucleoli. The number of Cajal bodies per nucleus was cell cycle-dependent, with higher numbers occurring during G2 phase. Human ES cells contained a high coilin level in the nucleoplasm, but coilin-positive Cajal bodies were also identified in nuclei of mouse and human ES cells. Coilin, but not SMN, recognized UVA-induced DNA lesions, which was cell cycle-independent. Treatment with γ-radiation reduced the localized movement of Cajal bodies in many cell types and GFP-coilin fluorescence recovery after photobleaching was very fast in nucleoplasm in comparison with GFP-coilin recovery in DNA lesions. By contrast, nucleolus-localized coilin displayed very slow fluorescence recovery after photobleaching, which indicates very slow rates of protein diffusion, especially in nucleoli of mouse ES cells.
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Affiliation(s)
- Eva Bártová
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Veronika Foltánková
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Soňa Legartová
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Petra Sehnalová
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Dmitry V Sorokin
- Faculty of Informatics; Masaryk University; Brno, Czech Republic
| | - Jana Suchánková
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
| | - Stanislav Kozubek
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Brno, Czech Republic
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Pereira-Castro I, Costa AMS, Oliveira MJ, Barbosa I, Rocha AS, Azevedo L, da Costa LT. Characterization of human NLZ1/ZNF703 identifies conserved domains essential for proper subcellular localization and transcriptional repression. J Cell Biochem 2013; 114:120-33. [PMID: 22886885 DOI: 10.1002/jcb.24309] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 07/26/2012] [Indexed: 11/06/2022]
Abstract
NET family members have recently emerged as important players in the development of multiple structures, from the trachea of fly larvae to the vertebrate eye and human breast cancers. However, their mechanisms of action are still poorly understood, and we lack a detailed characterization of their functional domains, as well as gene expression patterns-particularly in adult mammals. Here, we present a characterization of human NLZ1/ZNF703 (NocA-like zinc finger 1/Zinc finger 703), one of the two human NET family member genes. We show that the gene is ubiquitously expressed in adult human and mouse tissues, that three mRNA species with the same coding sequence are generated by alternative polyadenylation, and that the encoded protein contains six evolutionarily conserved domains, three of which are specific to NET proteins. Finally, we present functional evidence that these domains are necessary for proper subcellular distribution of and transcription repression by the NLZ1 protein, but not for its interaction with Groucho family co-repressors.
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Affiliation(s)
- Isabel Pereira-Castro
- IPATIMUP-Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal
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18
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YUAN C, LI XR, GU DD, GU Y, GAO YJ, CUI SJ. The Effect of Arabidopsis LFR Protein Domain on Its Co-transactivation and Subcellular Localization in Nucleus*. PROG BIOCHEM BIOPHYS 2012. [DOI: 10.3724/sp.j.1206.2012.00048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Bogolyubov DS, Kiselyov AM, Shabelnikov SV, Parfenov VN. Polyadenylated RNA and mRNA export factors in extrachromosomal nuclear domains of vitellogenic oocytes in the yellow mealworm Tenebrio molitor. ACTA ACUST UNITED AC 2012. [DOI: 10.1134/s1990519x12050045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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de Thé H, Le Bras M, Lallemand-Breitenbach V. The cell biology of disease: Acute promyelocytic leukemia, arsenic, and PML bodies. J Cell Biol 2012; 198:11-21. [PMID: 22778276 PMCID: PMC3392943 DOI: 10.1083/jcb.201112044] [Citation(s) in RCA: 164] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 06/15/2012] [Indexed: 12/12/2022] Open
Abstract
Acute promyelocytic leukemia (APL) is driven by a chromosomal translocation whose product, the PML/retinoic acid (RA) receptor α (RARA) fusion protein, affects both nuclear receptor signaling and PML body assembly. Dissection of APL pathogenesis has led to the rediscovery of PML bodies and revealed their role in cell senescence, disease pathogenesis, and responsiveness to treatment. APL is remarkable because of the fortuitous identification of two clinically effective therapies, RA and arsenic, both of which degrade PML/RARA oncoprotein and, together, cure APL. Analysis of arsenic-induced PML or PML/RARA degradation has implicated oxidative stress in the biogenesis of nuclear bodies and SUMO in their degradation.
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Affiliation(s)
- Hugues de Thé
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche 944, Equipe labellisée par la Ligue Nationale contre le Cancer, 2 University Paris-Diderot, Sorbonne Paris Cité, Paris, France.
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Chaoui A, Watanabe Y, Touraine R, Baral V, Goossens M, Pingault V, Bondurand N. Identification and functional analysis of SOX10 missense mutations in different subtypes of Waardenburg syndrome. Hum Mutat 2011; 32:1436-49. [PMID: 21898658 DOI: 10.1002/humu.21583] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 07/28/2011] [Indexed: 11/09/2022]
Abstract
Waardenburg syndrome (WS) is a rare disorder characterized by pigmentation defects and sensorineural deafness, classified into four clinical subtypes, WS1-S4. Whereas the absence of additional features characterizes WS2, association with Hirschsprung disease defines WS4. WS is genetically heterogeneous, with six genes already identified, including SOX10. About 50 heterozygous SOX10 mutations have been described in patients presenting with WS2 or WS4, with or without myelination defects of the peripheral and central nervous system (PCWH, Peripheral demyelinating neuropathy-Central dysmyelinating leukodystrophy-Waardenburg syndrome-Hirschsprung disease, or PCW, PCWH without HD). The majority are truncating mutations that most often remove the main functional domains of the protein. Only three missense mutations have been thus far reported. In the present study, novel SOX10 missense mutations were found in 11 patients and were examined for effects on SOX10 characteristics and functions. The mutations were associated with various phenotypes, ranging from WS2 to PCWH. All tested mutations were found to be deleterious. Some mutants presented with partial cytoplasmic redistribution, some lost their DNA-binding and/or transactivation capabilities on various tissue-specific target genes. Intriguingly, several mutants were redistributed in nuclear foci. Whether this phenomenon is a cause or a consequence of mutation-associated pathogenicity remains to be determined, but this observation could help to identify new SOX10 modes of action.
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Affiliation(s)
- Asma Chaoui
- INSERM U955, Hôpital Henri Mondor, Créteil, France
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22
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Novotný I, Blažíková M, Staneˇk D, Herman P, Malinsky J. In vivo kinetics of U4/U6·U5 tri-snRNP formation in Cajal bodies. Mol Biol Cell 2011; 22:513-23. [PMID: 21177826 PMCID: PMC3038649 DOI: 10.1091/mbc.e10-07-0560] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 12/08/2010] [Accepted: 12/15/2010] [Indexed: 01/09/2023] Open
Abstract
The U4/U6·U5 tri-small nuclear ribonucleoprotein particle (tri-snRNP) is an essential pre-mRNA splicing factor, which is assembled in a stepwise manner before each round of splicing. It was previously shown that the tri-snRNP is formed in Cajal bodies (CBs), but little is known about the dynamics of this process. Here we created a mathematical model of tri-snRNP assembly in CBs and used it to fit kinetics of individual snRNPs monitored by fluorescence recovery after photobleaching. A global fitting of all kinetic data determined key reaction constants of tri-snRNP assembly. Our model predicts that the rates of di-snRNP and tri-snRNP assemblies are similar and that ∼230 tri-snRNPs are assembled in one CB per minute. Our analysis further indicates that tri-snRNP assembly is approximately 10-fold faster in CBs than in the surrounding nucleoplasm, which is fully consistent with the importance of CBs for snRNP formation in rapidly developing biological systems. Finally, the model predicted binding between SART3 and a CB component. We tested this prediction by Förster resonance energy transfer and revealed an interaction between SART3 and coilin in CBs.
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MESH Headings
- Antigens, Neoplasm/genetics
- Antigens, Neoplasm/metabolism
- Cell Line, Tumor
- Cell Nucleus/genetics
- Cell Nucleus/metabolism
- Coiled Bodies/genetics
- Coiled Bodies/metabolism
- HeLa Cells
- Humans
- Kinetics
- Models, Molecular
- Nuclear Proteins/metabolism
- Protein Binding/genetics
- RNA Helicases/genetics
- RNA Helicases/metabolism
- RNA Precursors/genetics
- RNA Precursors/metabolism
- RNA Splicing/genetics
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Ribonucleoprotein, U4-U6 Small Nuclear/genetics
- Ribonucleoprotein, U4-U6 Small Nuclear/metabolism
- Ribonucleoprotein, U5 Small Nuclear/genetics
- Ribonucleoprotein, U5 Small Nuclear/metabolism
- Ribonucleoproteins, Small Nuclear/genetics
- Ribonucleoproteins, Small Nuclear/metabolism
- Spliceosomes/genetics
- Spliceosomes/metabolism
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Affiliation(s)
- Ivan Novotný
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague 4, Czech Republic
| | - Michaela Blažíková
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 142 20 Prague 4, Czech Republic
- Faculty of Mathematics and Physics, Charles University, 121 16 Prague 2, Czech Republic
| | - David Staneˇk
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague 4, Czech Republic
| | - Petr Herman
- Faculty of Mathematics and Physics, Charles University, 121 16 Prague 2, Czech Republic
| | - Jan Malinsky
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 142 20 Prague 4, Czech Republic
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Mathias MIC, Arnosti A, Brienza PD, Furquim KCS, Oliveira PRD, Denardi SE, Bechara GH. The dynamics of RNA participation in the vitellogenesis of Rhipicephalus sanguineus ticks Latreille 1806 (Acari:Ixodidae). I. Nucleoli or Cajal bodies? Micron 2010; 41:870-6. [DOI: 10.1016/j.micron.2010.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 04/08/2010] [Accepted: 04/13/2010] [Indexed: 11/26/2022]
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Hebert MD. Phosphorylation and the Cajal body: modification in search of function. Arch Biochem Biophys 2010; 496:69-76. [PMID: 20193656 PMCID: PMC2850958 DOI: 10.1016/j.abb.2010.02.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Accepted: 02/24/2010] [Indexed: 12/25/2022]
Abstract
The Cajal body (CB) is a subnuclear domain that contains proteins and factors involved in a diverse range of activities including ribonucleoprotein maturation, histone gene transcription and telomerase assembly. Among these activities, the CBs' role in small nuclear ribonucleoprotein (snRNP) biogenesis is best characterized. Although CBs are found in plants, flies and mammals, not all cell types contain CBs. Rather, CBs are most prominent in transcriptionally active cells, such as cancer and neuronal cells. Many CB components, including the CB marker protein coilin, are phosphorylated in humans. The functional consequence of phosphorylation on CB assembly, activity and disassembly is largely unknown. Also unknown are the signaling pathways, kinases and phosphatases that act upon proteins which localize in the CB. The goal of this review is to demonstrate the need for a concerted effort towards elucidating the functional consequence of phosphorylation on CB formation and activity.
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Affiliation(s)
- Michael D Hebert
- Department of Biochemistry, The University of Mississippi Medical Center, Jackson, MS 39216-4505, USA
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25
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Mohamad N, Bodén M. The proteins of intra-nuclear bodies: a data-driven analysis of sequence, interaction and expression. BMC SYSTEMS BIOLOGY 2010; 4:44. [PMID: 20388198 PMCID: PMC2859750 DOI: 10.1186/1752-0509-4-44] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Accepted: 04/13/2010] [Indexed: 12/21/2022]
Abstract
Background Cajal bodies, nucleoli, PML nuclear bodies, and nuclear speckles are morpohologically distinct intra-nuclear structures that dynamically respond to cellular cues. Such nuclear bodies are hypothesized to play important regulatory roles, e.g. by sequestering and releasing transcription factors in a timely manner. While the nucleolus and nuclear speckles have received more attention experimentally, the PML nuclear body and the Cajal body are still incompletely characterized in terms of their roles and protein complement. Results By collating recent experimentally verified data, we find that almost 1000 proteins in the mouse nuclear proteome are known to associate with one or more of the nuclear bodies. Their gene ontology terms highlight their regulatory roles: splicing is confirmed to be a core activity of speckles and PML nuclear bodies house a range of proteins involved in DNA repair. We train support-vector machines to show that nuclear proteins contain discriminative sequence features that can be used to identify their intra-nuclear body associations. Prediction accuracy is highest for nucleoli and nuclear speckles. The trained models are also used to estimate the full protein complement of each nuclear body. Protein interactions are found primarily to link proteins in the nuclear speckles with proteins from other compartments. Cell cycle expression data provide support for increased activity in nucleoli, nuclear speckles and PML nuclear bodies especially during S and G2 phases. Conclusions The large-scale analysis of the mouse nuclear proteome sheds light on the functional organization of physically embodied intra-nuclear compartments. We observe partial support for the hypothesis that the physical organization of the nucleus mirrors functional modularity. However, we are unable to unambiguously identify proteins' intra-nuclear destination, suggesting that critical drivers behind of intra-nuclear translocation are yet to be identified.
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Affiliation(s)
- Nurul Mohamad
- Institute for Molecular Bioscience, The University of Queensland QLD 4072, Australia
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26
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Toyota CG, Davis MD, Cosman AM, Hebert MD. Coilin phosphorylation mediates interaction with SMN and SmB'. Chromosoma 2010; 119:205-15. [PMID: 19997741 PMCID: PMC2839002 DOI: 10.1007/s00412-009-0249-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 11/11/2009] [Accepted: 11/11/2009] [Indexed: 11/29/2022]
Abstract
Cajal bodies (CBs) are subnuclear domains that participate in spliceosomal small nuclear ribonucleoprotein (snRNP) biogenesis and play a part in the assembly of the spliceosomal complex. The CB marker protein, coilin, interacts with survival of motor neuron (SMN) and Sm proteins. Several coilin phosphoresidues have been identified by mass spectrometric analysis. Phosphorylation of coilin affects its self-interaction and localization in the nucleus. We hypothesize that coilin phosphorylation also impacts its binding to SMN and Sm proteins. In vitro binding studies with a C-terminal fragment of coilin and corresponding phosphomimics show that SMN binds preferentially to dephosphorylated analogs and that SmB' binds preferentially to phosphomimetic constructs. Bacterially expressed full-length coilin binds more SMN and SmB' than does the C-terminal fragment. Co-immunoprecipitation and phosphatase experiments show that SMN also binds dephosphorylated coilin in vivo. These data show that phosphorylation of coilin influences interaction with its target proteins and, thus, may be significant in managing the flow of snRNPs through the CB.
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Affiliation(s)
- Cory G. Toyota
- Department of Biochemistry, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Misty D. Davis
- Department of Biochemistry, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Angela M. Cosman
- Department of Biochemistry, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Michael D. Hebert
- Department of Biochemistry, University of Mississippi Medical Center, Jackson, MS 39216, USA
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Haudek KC, Spronk KJ, Voss PG, Patterson RJ, Wang JL, Arnoys EJ. Dynamics of galectin-3 in the nucleus and cytoplasm. BIOCHIMICA ET BIOPHYSICA ACTA 2010; 1800:181-9. [PMID: 19616076 PMCID: PMC2815258 DOI: 10.1016/j.bbagen.2009.07.005] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Accepted: 07/06/2009] [Indexed: 11/29/2022]
Abstract
This review summarizes selected studies on galectin-3 (Gal3) as an example of the dynamic behavior of a carbohydrate-binding protein in the cytoplasm and nucleus of cells. Within the 15-member galectin family of proteins, Gal3 (M(r) approximately 30,000) is the sole representative of the chimera subclass in which a proline- and glycine-rich NH(2)-terminal domain is fused onto a COOH-terminal carbohydrate recognition domain responsible for binding galactose-containing glycoconjugates. The protein shuttles between the cytoplasm and nucleus on the basis of targeting signals that are recognized by importin(s) for nuclear localization and exportin-1 (CRM1) for nuclear export. Depending on the cell type, specific experimental conditions in vitro, or tissue location, Gal3 has been reported to be exclusively cytoplasmic, predominantly nuclear, or distributed between the two compartments. The nuclear versus cytoplasmic distribution of the protein must reflect, then, some balance between nuclear import and export, as well as mechanisms of cytoplasmic anchorage or binding to a nuclear component. Indeed, a number of ligands have been reported for Gal3 in the cytoplasm and in the nucleus. Most of the ligands appear to bind Gal3, however, through protein-protein interactions rather than through protein-carbohydrate recognition. In the cytoplasm, for example, Gal3 interacts with the apoptosis repressor Bcl-2 and this interaction may be involved in Gal3's anti-apoptotic activity. In the nucleus, Gal3 is a required pre-mRNA splicing factor; the protein is incorporated into spliceosomes via its association with the U1 small nuclear ribonucleoprotein (snRNP) complex. Although the majority of these interactions occur via the carbohydrate recognition domain of Gal3 and saccharide ligands such as lactose can perturb some of these interactions, the significance of the protein's carbohydrate-binding activity, per se, remains a challenge for future investigations.
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Affiliation(s)
- Kevin C. Haudek
- Department of Biochemistry and Molecular Biology Michigan State University, East Lansing, MI 48824
| | - Kimberly J. Spronk
- Department of Chemistry and Biochemistry Calvin College, Grand Rapids, MI 49546
| | - Patricia G. Voss
- Department of Biochemistry and Molecular Biology Michigan State University, East Lansing, MI 48824
| | - Ronald J. Patterson
- Department of Microbiology and Molecular Genetics Michigan State University, East Lansing, MI 48824
| | - John L. Wang
- Department of Biochemistry and Molecular Biology Michigan State University, East Lansing, MI 48824
| | - Eric J. Arnoys
- Department of Chemistry and Biochemistry Calvin College, Grand Rapids, MI 49546
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Cisterna B, Biggiogera M. Ribosome biogenesis: from structure to dynamics. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 284:67-111. [PMID: 20875629 DOI: 10.1016/s1937-6448(10)84002-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this chapter we describe the status of the research concerning the nucleolus, the major nuclear body. The nucleolus has been recognized as a dynamic organelle with many more functions than one could imagine. In fact, in addition to its fundamental role in the biogenesis of preribosomes, the nucleolus takes part in many other cellular processes and functions, such as the cell-cycle control and the p53 pathway: the direct or indirect involvement of the nucleolus in these various processes makes it sensitive to their alteration. Moreover, it is worth noting that the different nucleolar factors participating to independent mechanisms show different dynamics of association/disassociation with the nucleolar body.
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Affiliation(s)
- Barbara Cisterna
- Laboratory of Cell Biology and Neurobiology, Department of Animal Biology, University of Pavia, Pavia, Italy
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Nuclear bodies: random aggregates of sticky proteins or crucibles of macromolecular assembly? Dev Cell 2009; 17:639-47. [PMID: 19922869 DOI: 10.1016/j.devcel.2009.10.017] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The principles of self-assembly and self-organization are major tenets of molecular and cellular biology. Governed by these principles, the eukaryotic nucleus is composed of numerous subdomains and compartments, collectively described as nuclear bodies. Emerging evidence reveals that associations within and between various nuclear bodies and genomic loci are dynamic and can change in response to cellular signals. This review will discuss recent progress in our understanding of how nuclear body components come together, what happens when they form, and what benefit these subcellular structures may provide to the tissues or organisms in which they are found.
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Walker MP, Tian L, Matera AG. Reduced viability, fertility and fecundity in mice lacking the cajal body marker protein, coilin. PLoS One 2009; 4:e6171. [PMID: 19587784 PMCID: PMC2702818 DOI: 10.1371/journal.pone.0006171] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Accepted: 06/02/2009] [Indexed: 12/02/2022] Open
Abstract
Background Coilin is the signature protein of the Cajal body, a conserved nuclear organelle involved in multiple aspects of small ribonucleoprotein (RNP) biogenesis. Coilin is required for Cajal body homeostasis in both plants and animals. Mice lacking coilin are viable when the mutation is crossed to an outbred strain but only partially viable when crossed to inbred lines. Methodology/Principal Findings In order to clarify this issue, we backcrossed the coilin deletion onto the C57BL6/J background for ten generations and then investigated the consequences of coilin removal on overall viability and reproductive success. We conclude that semi-lethal phenotype observed in mixed-background crosses is due to loss of the Coilin gene (or a very tightly-linked locus). Interestingly, coilin knockout embryos die relatively late in gestation, between E13.5 and birth. We show that the maternal contribution of coilin is not important for organismal viability. Importantly, coilin knockout mice display significant fertility and fecundity defects. Mutant males that escape the embryonic lethality display reduced testis size, however, both males and females contribute to the observed reduction in reproductive fitness. Conclusions/Significance The evolutionary conservation of coilin from plants to animals suggests that the protein plays an important role, perhaps coordinating the activities of various RNA-processing machineries. Our observations are consistent with the idea that coilin functions to ensure robust organismal development, especially during periods of rapid growth.
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Affiliation(s)
- Michael P. Walker
- Department of Genetics, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
- Departments of Biology and Genetics, Program in Molecular Biology & Biotechnology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Liping Tian
- Department of Genetics, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - A. Gregory Matera
- Department of Genetics, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
- Departments of Biology and Genetics, Program in Molecular Biology & Biotechnology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
- * E-mail:
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HSPB7 is a SC35 speckle resident small heat shock protein. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1343-53. [PMID: 19464326 DOI: 10.1016/j.bbamcr.2009.05.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Revised: 05/13/2009] [Accepted: 05/15/2009] [Indexed: 01/15/2023]
Abstract
BACKGROUND The HSPB family is one of the more diverse families within the group of HSP families. Some members have chaperone-like activities and/or play a role in cytoskeletal stabilization. Some members also show a dynamic, stress-induced translocation to SC35 splicing speckles. If and how these features are interrelated and if they are shared by all members are yet unknown. METHODS Tissue expression data and interaction and co-regulated gene expression data of the human HSPB members was analyzed using bioinformatics. Using a gene expression library, sub-cellular distribution of the diverse members was analyzed by confocal microscopy. Chaperone activity was measured using a cellular luciferase refolding assay. RESULTS Online databases did not accurately predict the sub-cellular distribution of all the HSPB members. A novel and non-predicted finding was that HSPB7 constitutively localized to SC35 splicing speckles, driven by its N-terminus. Unlike HSPB1 and HSPB5, that chaperoned heat unfolded substrates and kept them folding competent, HSPB7 did not support refolding. CONCLUSION Our data suggest a non-chaperone-like role of HSPB7 at SC35 speckles. GENERAL SIGNIFICANCE The functional divergence between HSPB members seems larger than previously expected and also includes non-canonical members lacking classical chaperone-like functions.
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Hearst SM, Gilder AS, Negi SS, Davis MD, George EM, Whittom AA, Toyota CG, Husedzinovic A, Gruss OJ, Hebert MD. Cajal-body formation correlates with differential coilin phosphorylation in primary and transformed cell lines. J Cell Sci 2009; 122:1872-81. [PMID: 19435804 DOI: 10.1242/jcs.044040] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Cajal bodies (CBs) are nuclear structures that are thought to have diverse functions, including small nuclear ribonucleoprotein (snRNP) biogenesis. The phosphorylation status of coilin, the CB marker protein, might impact CB formation. We hypothesize that primary cells, which lack CBs, contain different phosphoisoforms of coilin compared with that found in transformed cells, which have CBs. Localization, self-association and fluorescence recovery after photobleaching (FRAP) studies on coilin phosphomutants all suggest this modification impacts the function of coilin and may thus contribute towards CB formation. Two-dimensional gel electrophoresis demonstrates that coilin is hyperphosphorylated in primary cells compared with transformed cells. mRNA levels of the nuclear phosphatase PPM1G are significantly reduced in primary cells and expression of PPM1G in primary cells induces CBs. Additionally, PPM1G can dephosphorylate coilin in vitro. Surprisingly, however, expression of green fluorescent protein alone is sufficient to form CBs in primary cells. Taken together, our data support a model whereby coilin is the target of an uncharacterized signal transduction cascade that responds to the increased transcription and snRNP demands found in transformed cells.
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Affiliation(s)
- Scoty M Hearst
- Department of Biochemistry, The University of Mississippi Medical Center, Jackson, MS 39216, USA
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Lafarga M, Casafont I, Bengoechea R, Tapia O, Berciano MT. Cajal's contribution to the knowledge of the neuronal cell nucleus. Chromosoma 2009; 118:437-43. [PMID: 19404660 DOI: 10.1007/s00412-009-0212-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 04/02/2009] [Accepted: 04/02/2009] [Indexed: 11/26/2022]
Abstract
In 1906, the Spanish neurobiologist Santiago Ramón y Cajal was awarded the Nobel Prize in Physiology or Medicine in recognition of his work on the structure of neurons and their connections. Cajal is commonly regarded as the father of modern neuroscience. What is less well known is that Cajal also had a great interest in intracellular neuronal structures and developed the reduced silver nitrate method for the study of neurofibrils (neurofilaments) and nuclear subcompartments. It was in 1903 that Cajal discovered the "accessory body" ("Cajal body") and seven years later, published an article on the organization of the cell nucleus in mammalian neurons that represents a masterpiece of nuclear structure at the light microscopy level. In addition to the accessory body, it includes the analysis of several nuclear components currently recognized as fibrillar centers of the nucleolus, nuclear speckles of splicing factors, transcription foci, nuclear matrix, and the double nuclear membrane. The aim of this article is to revisit Cajal's contributions to the knowledge of the neuronal nucleus in light of our current understanding of nuclear structure and function.
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Affiliation(s)
- Miguel Lafarga
- Department of Anatomy and Cell Biology and Centro de Investigación Biomédica en Red sobre Enferemedades Neurodegenerativas, University of Cantabria, Avd. Cardenal Herrera Oria s/n, 39011, Santander, Spain.
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Bogolyubov D, Stepanova I, Parfenov V. Universal nuclear domains of somatic and germ cells: some lessons from oocyte interchromatin granule cluster and Cajal body structure and molecular composition. Bioessays 2009; 31:400-9. [DOI: 10.1002/bies.200800100] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Abstract
AbstractThe effects of ultra wideband pulse radiation on human cells were investigated. The density of the flow of energy on the surface of irradiated object varied from 10−6 to 10−2 W/cm2 with exposure of 10 s. It was shown that heterochromatin granule quantity in cell nuclei increased under the influence of radiation from 10−4 to 10−2 W/cm2. In some intervals the effect increased with irradiation dose. At irradiation intensity 10−3 W/cm2 the process of heterochromatin granule formation was fully reversible after 2 h of recovery; at intensity 10−2 W/cm2 the reversion of irradiation effects was not full. The data obtained indicated the strong biological activity of ultra wideband ultra short pulse radiation.
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Sivaramakrishnan G, Sun Y, Tan SK, Lin VCL. Dynamic localization of tripartite motif-containing 22 in nuclear and nucleolar bodies. Exp Cell Res 2009; 315:1521-32. [PMID: 19331816 DOI: 10.1016/j.yexcr.2009.01.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 01/21/2009] [Accepted: 01/29/2009] [Indexed: 01/08/2023]
Abstract
Tripartite motif-containing 22 (TRIM22) exhibits antiviral and growth inhibitory properties, but there has been no study on the localization and dynamics of the endogenous TRIM22 protein. We report here that TRIM22 is dramatically induced by progesterone in MDA-MB-231-derived ABC28 cells and T47D cells. This induction was associated with an increase in TRIM22 nuclear bodies (NB), and an even more prominent increase in nucleolar TRIM22 bodies. Distinct endogenous TRIM22 NB were also demonstrated in several other cell lines including MCF7 and HeLa cells. These TRIM22 NB resemble Cajal bodies, co-localized with these structures and co-immunoprecipitated with p80-coilin. However, IFNgamma-induced TRIM22 in HeLa and MCF7 cells did not form NB, implying the forms and distribution of TRIM22 are regulated by specific cellular signals. This notion is also supported by the observation that TRIM22 NB undergoes dynamic cell-cycle dependent changes in distribution such that TRIM22 NB started to form in early G0/G1 but became dispersed in the S-phase. In light of its potential antiviral and antitumor properties, the findings here provide an interesting gateway to study the relationship between the different forms and functions of TRIM22.
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Affiliation(s)
- Gayathri Sivaramakrishnan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
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Abstract
BACKGROUND INFORMATION The nucleolus is a dynamic structure. It has been demonstrated that nucleolar proteins rapidly associate with and dissociate from nucleolar components in continuous exchanges with the nucleoplasm using GFP (green fluorescent protein)-tagged proteins. However, how the exchanges within one nucleolus and between nucleoli within the nuclear volume occurred is still poorly understood. RESULTS The movement of PAGFP (photoactivatable GFP)-tagged proteins that become visible after photoactivation can be followed. In the present study, we establish the protocol allowing quantification of the traffic of PAGFP-tagged nucleolar proteins in nuclei containing two nucleoli. The traffic in the activated area, at the periphery of the activated area and to the neighbouring nucleolus is measured. Protein B23 is rapidly replaced in the activated area, and at the periphery of the activated area the steady state suggests intranucleolar recycling of B23; this recycling is LMB (leptomycin B)-sensitive. The pool of activated B23 is equally distributed in the volume of the two nucleoli within 2 min. The three-dimensional distribution of the proteins Nop52 and fibrillarin is less rapid than that of B23 but is also LMB-sensitive. In contrast, traffic of fibrillarin from the nucleoli to the CB (Cajal body) was not modified by LMB. CONCLUSIONS We propose that the steady state of nucleolar proteins in nucleoli depends on the affinity of the proteins for their partners and on intranucleolar recycling. This steady state can be impaired by LMB but not the uptake in the neighbouring nucleolus or the CB.
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Isitor GN, Asgarali Z, Pouching K. Nucleic acid distribution pattern in avian erythrocytes and mammalian lymphocytes: comparative studies by fluorescence microscopy and digital imaging analytical techniques. Res Vet Sci 2008; 85:418-32. [PMID: 18448142 DOI: 10.1016/j.rvsc.2008.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Revised: 02/06/2008] [Accepted: 03/10/2008] [Indexed: 10/22/2022]
Abstract
Nucleated erythrocytes of healthy domestic chicken and ducks, and lymphocytes of healthy Sprague Dawley rats were evaluated for nucleic acid distribution pattern, employing light and fluorescence microscopy procedures, as well as digital imaging analytical methods. The results demonstrate a unique organization of nuclear DNA of mature chicken and duck erythrocytes, as well as immature duck erythrocytes, as delineated spherical nuclear bodies that mostly corresponded with euchromatin zones of the cells in routine Wright-stain blood smears. The nuclear DNA of the rat lymphocytes, on the other hand, was observed as a more diffuse green fluorescing nuclear areas, with punctate variably-sized diffuse areas of RNA red fluorescence. RNA red color fluorescence was also evident in the narrow cytoplasm of the lymphocytes, especially in large lymphocytes, in comparison with the cytoplasm of the mature avian erythrocytes that completely lacked any nucleic acid fluorescence. Nuclear RNA fluorescence was lacking in the mature chicken erythrocytes, compared with those of the mature and immature duck erythrocytes as well as lymphocytes of both avian and rats blood. The significance of these findings lies in the establishment of normal benchmarks for the nuclear and cytoplasmic nucleic acid pattern in eukaryotic cells. These normal benchmarks become valuable in rapid diagnostic situations associated with pathologies, such as the presence of viral nuclear and cytoplasmic inclusion bodies that can alter the nucleic acid pattern of the host cells, and in conditions of cellular abnormal protein aggregations. Variability of cellular nucleic acid pattern can also aid in prognostic assessments of neoplastic conditions.
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Affiliation(s)
- G N Isitor
- Department of Preclinical Sciences, The University of The West Indies, St. Augustine Campus, Trinidad, W.I., Trinidad and Tobago.
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Abstract
The nucleolus is a multifunctional compartment of the eukaryotic nucleus. Besides its well-recognised role in transcription and processing of ribosomal RNA and the assembly of ribosomal subunits, the nucleolus has functions in the processing and assembly of a variety of RNPs and is involved in cell cycle control and senescence and as a sensor of stress. Historically, nucleoli have been tenuously linked to the biogenesis and, in particular, export of mRNAs in yeast and mammalian cells. Recently, data from plants have extended the functions in which the plant nucleolus is involved to include transcriptional gene silencing as well as mRNA surveillance and nonsense-mediated decay, and mRNA export. The nucleolus in plants may therefore have important roles in the biogenesis and quality control of mRNAs.
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Affiliation(s)
- Anireddy S. N. Reddy
- Department of Biology and Program in Molecular Plant Biology, Colorado State University, Fort Collins, CO 80523 USA
| | - Maxim Golovkin
- Department of Microbiology, Thomas Jefferson University, Philadelphia, PA 19107 USA
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Bogolyubov D, Parfenov V. Chapter 2 Structure of the Insect Oocyte Nucleus with Special Reference to Interchromatin Granule Clusters and Cajal Bodies. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2008; 269:59-110. [DOI: 10.1016/s1937-6448(08)01002-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Coulon A, Beslon G, Gandrillon O. Large multiprotein structures modeling and simulation: the need for mesoscopic models. Methods Mol Biol 2008; 484:537-558. [PMID: 18592200 DOI: 10.1007/978-1-59745-398-1_32] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Recent observational techniques based upon confocal microscopy make it possible to observe cells at a scale that has never been probed before: the mesoscopic scale. In the eukaryotic cell nucleus, many objects demonstrating phenomena occurring at this scale, such as nuclear bodies, are current subjects of investigations. But from a modeling perspective, this scale has not been widely explored, and hence there is a lack of suitable models for such studies. By reviewing higher and lower scale modeling techniques, we analyze their relevance in the context of mesoscale phenomena. We emphasize important characteristics that should be included in a mesoscopic model: an explicit continuous three-dimensional space with discrete simplified molecules that still have the characteristics of steric volume exclusion and realistic distant interaction forces. Then we present 3DSPI, a model dedicated to studies of nuclear bodies based on a simple formalism inspired from molecular dynamics and coarse-grained models: particles interacting through a potential energy function and driven by an overdamped Langevin equation. Finally, we present the features expected to be included in the model, pointing out the difficulties that might arise.
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Kono K, Harano Y, Hoshino H, Kobayashi M, Bazett-Jones DP, Muto A, Igarashi K, Tashiro S. The mobility of Bach2 nuclear foci is regulated by SUMO-1 modification. Exp Cell Res 2007; 314:903-13. [PMID: 18201693 DOI: 10.1016/j.yexcr.2007.12.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Revised: 11/30/2007] [Accepted: 12/12/2007] [Indexed: 11/15/2022]
Abstract
The small ubiquitin-like modifier-1 (SUMO-1) modulates the functions of nuclear proteins by changing their structure and/or subnuclear localization. Several nuclear proteins form dynamic higher order nuclear structures, termed non-chromatin nuclear domains, which are involved in the regulation of nuclear function. However, the role that SUMO modification of the component proteins plays in the regulation of the activity and function of nuclear domains is unclear. Here we demonstrate that nuclear domains formed by Bach2, a transcription repressor, show restricted movement and undergo fusion events upon oxidative stress. Mutation of the SUMO-acceptor lysines in Bach2 alters the behavior of these nuclear foci and results in a decreased frequency of fusion events. We propose that SUMO modification is an important regulatory system for the mobility of the nuclear domains formed by Bach2.
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Affiliation(s)
- Kazuteru Kono
- Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Kasumi 1-2-3, Minamiku, Hiroshima 734-8553, Japan
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Sun J, Xu H, Negi S, Subramony SH, Hebert MD. Differential effects of polyglutamine proteins on nuclear organization and artificial reporter splicing. J Neurosci Res 2007; 85:2306-17. [PMID: 17526020 DOI: 10.1002/jnr.21369] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Nuclear inclusions formed by proteins with expanded polyglutamine tracts are found in several neurodegenerative diseases. The effect of nuclear inclusions formed by these disease proteins on the functional organization of the nucleus is only partially understood. In particular, it is not known whether polyglutamine disease proteins disrupt the function of Cajal bodies, which are subnuclear domains that play a role in the biogenesis of small nuclear ribonucleoproteins (snRNPs). snRNPs are an integral part of the pre-mRNA splicing machinery, so it is possible that mutant proteins that alter Cajal body activity indirectly affect pre-mRNA splicing. Here, we evaluate three different polyglutamine disease proteins--ataxin-1, ataxin-3, and huntingtin--for their ability to disrupt Cajal body localization and reduce the splicing of an artificial reporter in HeLa cells. Consistent with previous observations, ataxin-1 inclusions do not drastically alter the localization of Cajal bodies. In contrast, ataxin-3 inclusions associate with this structure. Inclusions formed by a fragment of the huntingtin protein do not associate with Cajal bodies or PML bodies, another subnuclear domain. Among the three disease proteins, only ataxin-3 significantly decreases the splicing of an artificial reporter. These results support the hypothesis that different mutant proteins vary in their ability to disrupt nuclear organization and function.
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Affiliation(s)
- June Sun
- Department of Neurology, The University of Mississippi Medical Center, Jackson, Mississippi 39216-4505, USA
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Shiohama A, Sasaki T, Noda S, Minoshima S, Shimizu N. Nucleolar localization of DGCR8 and identification of eleven DGCR8-associated proteins. Exp Cell Res 2007; 313:4196-207. [PMID: 17765891 DOI: 10.1016/j.yexcr.2007.07.020] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2007] [Revised: 07/05/2007] [Accepted: 07/05/2007] [Indexed: 12/22/2022]
Abstract
We identified 11 proteins that are associated with DGCR8 by immunoprecipitation assay and mass spectrometry. These proteins included Nucleolin, ILF3 and others, most of which appeared to be involved in the RNA processing or RNA transportation. We detected at least four kinds of protein complex, such as DROSHA/DGCR8, DGCR8/Nucleolin, DGCR8/ILF3 and ILF3/XPO5, by co-immunoprecipitation. The complex formation of DGCR8 with Nucleolin was dependent on RNA. Subcellular localization analysis by the immunofluorescent microscopy and immunoelectron microscopy indicated that DGCR8 locates at the nucleolus and small foci adjacent to splicing speckles in the nucleoplasm. Furthermore, the localization of DGCR8 at the nucleolus was changed by the inhibition of RNA transcription. Thus, our studies provided additional new evidence for the involvement of various protein complexes in the molecular mechanisms of apparently complex innate RNA interference machinery.
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Affiliation(s)
- Aiko Shiohama
- Department of Molecular Biology, Keio University School of Medicine, Tokyo, Japan; GSP Center, The Leading Institute of Keio University, Ibaraki, Japan
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Abstract
OBJECTIVES Intranuclear rodlets (INRs) are rod-shaped intranuclear inclusions that we have described in neurons of the human brain. We recently identified these structures in pancreatic islet cells. The objectives of this study are to describe the light microscopic features and cellular pattern of distribution of INRs in human pancreatic islet cells. METHODS Double immunofluorescence staining was performed on 5 human pancreatic tissue samples for the detection of class III beta tubulin (C3T) to detect INRs and for promyelocytic leukemia (PML) protein to examine the relationship between PML and INRs. RESULTS Intranuclear rodlets were detected in 22.99% of pancreatic B cells compared with only 3.11%, 1.80%, and 1.60% of A, D, and PP cells, respectively. Twenty-four percent of C3T-immunoreactive INRs showed partial or complete immunoreactivity for PML. Promyelocytic leukemia staining within the nuclei of B cells was confined to INRs and was not present in the typical PML bodies present in other cell types. Spatially, PML and C3T staining of islet cell INRs appeared to be mutually exclusive within individual INRs. CONCLUSIONS Intranuclear rodlets are present within the nuclei of pancreatic islet cells, where they reside predominantly but not exclusively in B cells. Immunoreactivity of B-cell INRs for PML suggests that the functional significance of INRs may be related to that of PML and/or PML bodies. Conversely, the exclusive localization of PML staining to INRs in B cells indicates that PML's function in B cells is selectively associated with INRs. The mutually exclusive pattern of PML and C3T staining suggests dynamic interactions between these 2 proteins in B-cell INRs. In light of evidence for the involvement of INRs and of PML bodies in disease, it will be of interest to investigate these structures in animal models of diabetes and in human diabetes.
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Affiliation(s)
- Wendy Prichett
- Centre for Cancer Therapeutics, The Ottawa Health Research Institute, Ottawa, Ontario, Canada
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Bogolyubov DS, Batalova FM, Ogorzałek A. Localization of interchromatin granule cluster and Cajal body components in oocyte nuclear bodies of the hemipterans. Tissue Cell 2007; 39:353-64. [PMID: 17889915 DOI: 10.1016/j.tice.2007.07.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Revised: 07/05/2007] [Accepted: 07/12/2007] [Indexed: 11/25/2022]
Abstract
An oocyte nucleus contains different extrachromosomal nuclear domains collectively called nuclear bodies (NBs). In the present work we revealed, using immunogold labeling electron microscopy, some marker components of interchromatin granule clusters (IGCs) and Cajal bodies (CBs) in morphologically heterogeneous oocyte NBs studied in three hemipteran species: Notostira elongata, Capsodes gothicus (Miridae) and Velia caprai (Veliidae). Both IGC and CB counterparts were revealed in oocyte nuclei of the studied species but morphological and biochemical criteria were found to be not sufficient to determine carefully the define type of oocyte NBs. We found that the molecular markers of the CBs (coilin and non-phosphorylated RNA polymerase II) and IGCs (SC35 protein) may be localized in the same NB. Anti-SC35 antibody may decorate not only a granular material representing "true" interchromatin granules but also masks some fibrillar parts of complex NBs. Our first observations on the hemipteran oocyte NBs confirm the high complexity and heterogeneity of insect oocyte IGCs and CBs in comparison with those in mammalian somatic cells and amphibian oocytes.
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Affiliation(s)
- D S Bogolyubov
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Avenue 4, 194064 St. Petersburg, Russia.
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Bogolyubov DS, Bogolyubova IO. SC35 Splicing factor and coilin are colocalized within the “endobodies” in oocytes of the spider Araneus diadematus. ACTA ACUST UNITED AC 2007. [DOI: 10.1134/s1990519x07040074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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48
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Narita T, Yung TMC, Yamamoto J, Tsuboi Y, Tanabe H, Tanaka K, Yamaguchi Y, Handa H. NELF interacts with CBC and participates in 3' end processing of replication-dependent histone mRNAs. Mol Cell 2007; 26:349-65. [PMID: 17499042 DOI: 10.1016/j.molcel.2007.04.011] [Citation(s) in RCA: 176] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 03/12/2007] [Accepted: 04/10/2007] [Indexed: 11/22/2022]
Abstract
Negative elongation factor (NELF) is a four subunit transcription elongation factor that has been implicated in numerous diseases ranging from neurological disorders to cancer. Here we show that NELF interacts with the nuclear cap binding complex (CBC), a multifunctional factor that plays important roles in several mRNA processing steps, and the two factors together participate in the 3' end processing of replication-dependent histone mRNAs, most likely through association with the histone stem-loop binding protein (SLBP). Strikingly, absence of NELF and CBC causes aberrant production of polyadenylated histone mRNAs. Moreover, NELF is physically associated with histone gene loci and forms distinct intranuclear foci that we call NELF bodies, which often overlap with Cajal bodies and cleavage bodies. Our results point to a surprising role of NELF in the 3' end processing of histone mRNAs and also suggest that NELF is a new factor that coordinates different mRNA processing steps during transcription.
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Affiliation(s)
- Takashi Narita
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama, Kanagawa 226-8501, Japan
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Tanaka T, Grusby MJ, Kaisho T. PDLIM2-mediated termination of transcription factor NF-kappaB activation by intranuclear sequestration and degradation of the p65 subunit. Nat Immunol 2007; 8:584-91. [PMID: 17468759 DOI: 10.1038/ni1464] [Citation(s) in RCA: 239] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Accepted: 04/05/2007] [Indexed: 11/08/2022]
Abstract
Activation of transcription factor NF-kappaB in the innate immune system is tightly regulated to prevent excessive inflammatory responses. How NF-kappaB activation is terminated, however, is not fully understood. Here we report that PDLIM2 negatively regulated NF-kappaB activity, acting as a nuclear ubiquitin E3 ligase targeting the p65 subunit of NF-kappaB. PDLIM2 bound to p65 and promoted p65 polyubiquitination. In addition, PDLIM2 targeted p65 to discrete intranuclear compartments where polyubiquitinated p65 was degraded by the proteasome. PDLIM2 deficiency resulted in larger amounts of nuclear p65, defective p65 ubiquitination and augmented production of proinflammatory cytokines in response to innate stimuli. Our findings delineate a pathway by which PDLIM2 terminates NF-kappaB activation through intranuclear sequestration and subsequent degradation.
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Affiliation(s)
- Takashi Tanaka
- Laboratory for Host Defense, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045, Japan
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Ihalainen TO, Niskanen EA, Jylhävä J, Turpeinen T, Rinne J, Timonen J, Vihinen-Ranta M. Dynamics and interactions of parvoviral NS1 protein in the nucleus. Cell Microbiol 2007; 9:1946-59. [PMID: 17419720 DOI: 10.1111/j.1462-5822.2007.00926.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Nuclear positioning and dynamic interactions of viral proteins with nuclear substructures play essential roles during infection with DNA viruses. Visualization of the intranuclear interactions and motility of the parvovirus replication protein (NS1) in living cells gives insight into specific parvovirus protein-cellular structure interactions. Confocal analysis of highly synchronized infected Norden Laboratory Feline Kidney cells showed accumulation of nuclear NS1 in discrete interchromosomal foci. NS1 fused with enhanced yellow fluorescence protein (NS1-EYFP) provided a marker in live cells for dynamics of NS1 traced by photobleaching techniques. Fluorescence Recovery after Photobleaching suggested that the NS1 protein is not freely diffusing but undergoes transient interactions with nuclear compartments. Fluorescence Loss in Photobleaching demonstrated for the first time the shuttling of a parvoviral protein between the nucleus and the cytoplasm as assayed with NS1-EYFP. Finally, time-lapse imaging of infected cells revealed that the intranuclear distribution of NS1-EYFP evolves dramatically starting from the formation of NS1 foci and proceeding to a homogenous distribution extending throughout the nucleus.
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Affiliation(s)
- Teemu O Ihalainen
- Department of Biological and Environmental Science, NanoScience Center, University of Jyväskylä, Survontie 9, FI-40014 Jyväskylä, Finland
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