1
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Nickerson JA, Momen-Heravi F. Long non-coding RNAs: roles in cellular stress responses and epigenetic mechanisms regulating chromatin. Nucleus 2024; 15:2350180. [PMID: 38773934 PMCID: PMC11123517 DOI: 10.1080/19491034.2024.2350180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/22/2024] [Indexed: 05/24/2024] Open
Abstract
Most of the genome is transcribed into RNA but only 2% of the sequence codes for proteins. Non-coding RNA transcripts include a very large number of long noncoding RNAs (lncRNAs). A growing number of identified lncRNAs operate in cellular stress responses, for example in response to hypoxia, genotoxic stress, and oxidative stress. Additionally, lncRNA plays important roles in epigenetic mechanisms operating at chromatin and in maintaining chromatin architecture. Here, we address three lncRNA topics that have had significant recent advances. The first is an emerging role for many lncRNAs in cellular stress responses. The second is the development of high throughput screening assays to develop causal relationships between lncRNAs across the genome with cellular functions. Finally, we turn to recent advances in understanding the role of lncRNAs in regulating chromatin architecture and epigenetics, advances that build on some of the earliest work linking RNA to chromatin architecture.
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Affiliation(s)
- Jeffrey A Nickerson
- Division of Genes & Development, Department of Pediatrics, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Fatemeh Momen-Heravi
- College of Dental Medicine, Columbia University Medical Center, New York, NY, USA
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, USA
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2
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Calandrelli R, Wen X, Charles Richard JL, Luo Z, Nguyen TC, Chen CJ, Qi Z, Xue S, Chen W, Yan Z, Wu W, Zaleta-Rivera K, Hu R, Yu M, Wang Y, Li W, Ma J, Ren B, Zhong S. Genome-wide analysis of the interplay between chromatin-associated RNA and 3D genome organization in human cells. Nat Commun 2023; 14:6519. [PMID: 37845234 PMCID: PMC10579264 DOI: 10.1038/s41467-023-42274-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 10/05/2023] [Indexed: 10/18/2023] Open
Abstract
The interphase genome is dynamically organized in the nucleus and decorated with chromatin-associated RNA (caRNA). It remains unclear whether the genome architecture modulates the spatial distribution of caRNA and vice versa. Here, we generate a resource of genome-wide RNA-DNA and DNA-DNA contact maps in human cells. These maps reveal the chromosomal domains demarcated by locally transcribed RNA, hereafter termed RNA-defined chromosomal domains. Further, the spreading of caRNA is constrained by the boundaries of topologically associating domains (TADs), demonstrating the role of the 3D genome structure in modulating the spatial distribution of RNA. Conversely, stopping transcription or acute depletion of RNA induces thousands of chromatin loops genome-wide. Activation or suppression of the transcription of specific genes suppresses or creates chromatin loops straddling these genes. Deletion of a specific caRNA-producing genomic sequence promotes chromatin loops that straddle the interchromosomal target sequences of this caRNA. These data suggest a feedback loop where the 3D genome modulates the spatial distribution of RNA, which in turn affects the dynamic 3D genome organization.
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Affiliation(s)
- Riccardo Calandrelli
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Xingzhao Wen
- Bioinformatics and Systems Biology Program, University of California San Diego, La Jolla, CA, USA
| | | | - Zhifei Luo
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Tri C Nguyen
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Chien-Ju Chen
- Bioinformatics and Systems Biology Program, University of California San Diego, La Jolla, CA, USA
| | - Zhijie Qi
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Shuanghong Xue
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Weizhong Chen
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Zhangming Yan
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Weixin Wu
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Kathia Zaleta-Rivera
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Rong Hu
- Department of Cellular and Molecular Medicine, Center for Epigenomics, University of California San Diego, La Jolla, CA, USA
- Ludwig Institute for Cancer Research, La Jolla, CA, USA
| | - Miao Yu
- Ludwig Institute for Cancer Research, La Jolla, CA, USA
| | - Yuchuan Wang
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Wenbo Li
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
| | - Jian Ma
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Bing Ren
- Department of Cellular and Molecular Medicine, Center for Epigenomics, University of California San Diego, La Jolla, CA, USA
- Ludwig Institute for Cancer Research, La Jolla, CA, USA
| | - Sheng Zhong
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA.
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3
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Valledor M, Byron M, Dumas B, Carone DM, Hall LL, Lawrence JB. Early chromosome condensation by XIST builds A-repeat RNA density that facilitates gene silencing. Cell Rep 2023; 42:112686. [PMID: 37384527 PMCID: PMC10461597 DOI: 10.1016/j.celrep.2023.112686] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 10/31/2022] [Accepted: 06/08/2023] [Indexed: 07/01/2023] Open
Abstract
XIST RNA triggers chromosome-wide gene silencing and condenses an active chromosome into a Barr body. Here, we use inducible human XIST to examine early steps in the process, showing that XIST modifies cytoarchitecture before widespread gene silencing. In just 2-4 h, barely visible transcripts populate the large "sparse zone" surrounding the smaller "dense zone"; importantly, density zones exhibit different chromatin impacts. Sparse transcripts immediately trigger immunofluorescence for H2AK119ub and CIZ1, a matrix protein. H3K27me3 appears hours later in the dense zone, which enlarges with chromosome condensation. Genes examined are silenced after compaction of the RNA/DNA territory. Insights into this come from the findings that the A-repeat alone can silence genes and rapidly, but only where dense RNA supports sustained histone deacetylation. We propose that sparse XIST RNA quickly impacts architectural elements to condense the largely non-coding chromosome, coalescing RNA density that facilitates an unstable, A-repeat-dependent step required for gene silencing.
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Affiliation(s)
- Melvys Valledor
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Meg Byron
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Brett Dumas
- Department of Medicine, Boston University Medical Center, Boston, MA 02118, USA
| | - Dawn M Carone
- Department of Biology, Swarthmore College, Swarthmore, PA 19081, USA
| | - Lisa L Hall
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA.
| | - Jeanne B Lawrence
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA; Department of Pediatrics, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA.
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4
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Soujanya M, Bihani A, Hajirnis N, Pathak RU, Mishra RK. Nuclear architecture and the structural basis of mitotic memory. CHROMOSOME RESEARCH : AN INTERNATIONAL JOURNAL ON THE MOLECULAR, SUPRAMOLECULAR AND EVOLUTIONARY ASPECTS OF CHROMOSOME BIOLOGY 2023; 31:8. [PMID: 36725757 DOI: 10.1007/s10577-023-09714-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/13/2022] [Accepted: 12/19/2022] [Indexed: 02/03/2023]
Abstract
The nucleus is a complex organelle that hosts the genome and is essential for vital processes like DNA replication, DNA repair, transcription, and splicing. The genome is non-randomly organized in the three-dimensional space of the nucleus. This functional sub-compartmentalization was thought to be organized on the framework of nuclear matrix (NuMat), a non-chromatin scaffold that functions as a substratum for various molecular processes of the nucleus. More recently, nuclear bodies or membrane-less subcompartments of the nucleus are thought to arise due to phase separation of chromatin, RNA, and proteins. The nuclear architecture is an amalgamation of the relative organization of chromatin, epigenetic landscape, the nuclear bodies, and the nucleoskeleton in the three-dimensional space of the nucleus. During mitosis, the nucleus undergoes drastic changes in morphology to the degree that it ceases to exist as such; various nuclear components, including the envelope that defines the nucleus, disintegrate, and the chromatin acquires mitosis-specific epigenetic marks and condenses to form chromosome. Upon mitotic exit, chromosomes are decondensed, re-establish hierarchical genome organization, and regain epigenetic and transcriptional status similar to that of the mother cell. How this mitotic memory is inherited during cell division remains a puzzle. NuMat components that are a part of the mitotic chromosome in the form of mitotic chromosome scaffold (MiCS) could potentially be the seeds that guide the relative re-establishment of the epigenome, chromosome territories, and the nuclear bodies. Here, we synthesize the advances towards understanding cellular memory of nuclear architecture across mitosis and propose a hypothesis that a subset of NuMat proteome essential for nucleation of various nuclear bodies are retained in MiCS to serve as seeds of mitotic memory, thus ensuring the daughter cells re-establish the complex status of nuclear architecture similar to that of the mother cells, thereby maintaining the pre-mitotic transcriptional status.
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Affiliation(s)
- Mamilla Soujanya
- CSIR - Centre for Cellular & Molecular Biology, Hyderabad, India
- AcSIR - Academy of Scientific and Innovative Research, Ghaziabad, India
| | - Ashish Bihani
- CSIR - Centre for Cellular & Molecular Biology, Hyderabad, India
| | - Nikhil Hajirnis
- CSIR - Centre for Cellular & Molecular Biology, Hyderabad, India
- Department of Anatomy and Neurobiology, University of Maryland, Baltimore, USA
| | - Rashmi U Pathak
- CSIR - Centre for Cellular & Molecular Biology, Hyderabad, India
| | - Rakesh K Mishra
- CSIR - Centre for Cellular & Molecular Biology, Hyderabad, India.
- AcSIR - Academy of Scientific and Innovative Research, Ghaziabad, India.
- TIGS - Tata Institute for Genetics and Society, Bangalore, India.
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5
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Ponting CP, Haerty W. Genome-Wide Analysis of Human Long Noncoding RNAs: A Provocative Review. Annu Rev Genomics Hum Genet 2022; 23:153-172. [PMID: 35395170 DOI: 10.1146/annurev-genom-112921-123710] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Do long noncoding RNAs (lncRNAs) contribute little or substantively to human biology? To address how lncRNA loci and their transcripts, structures, interactions, and functions contribute to human traits and disease, we adopt a genome-wide perspective. We intend to provoke alternative interpretation of questionable evidence and thorough inquiry into unsubstantiated claims. We discuss pitfalls of lncRNA experimental and computational methods as well as opposing interpretations of their results. The majority of evidence, we argue, indicates that most lncRNA transcript models reflect transcriptional noise or provide minor regulatory roles, leaving relatively few human lncRNAs that contribute centrally to human development, physiology, or behavior. These important few tend to be spliced and better conserved but lack a simple syntax relating sequence to structure and mechanism, and so resist simple categorization. This genome-wide view should help investigators prioritize individual lncRNAs based on their likely contribution to human biology.
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Affiliation(s)
- Chris P Ponting
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom;
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6
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Podgornaya OI. Nuclear organization by satellite DNA, SAF-A/hnRNPU and matrix attachment regions. Semin Cell Dev Biol 2022; 128:61-68. [PMID: 35484025 DOI: 10.1016/j.semcdb.2022.04.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/18/2022] [Accepted: 04/18/2022] [Indexed: 12/15/2022]
Abstract
The need of large-scale chromatin organization in the nucleus has become more and more appreciated. The higher order nuclear organization ultimately regulate a plethora of biological processes including transcription, DNA replication, and DNA repair. In this context, it is of critical importance to understand the mechanisms that allow higher order nuclear organization. Scaffold Attachment Factor A (SAF-A/hnRNPU), which was originally identified as the component of nuclear matrix, has emerged as an important regulator of higher order nuclear organization. It is shown that SAF-A/hnRNPU binds to tandem repeats (TRs) and scaffold/matrix attachment regions (S/MAR) in a sequence-non-specific, but structure-specific manner (e.g. DNA curvature). Recent studies showed that SAF-A interacts with chromatin-associated RNAs (caRNAs) to regulate interphase chromatin structures in a transcription-dependent manner. It is proposed that SAF-A/hnRNPU and caRNAs form a dynamic, transcriptionally responsive chromatin mesh that organizes chromatin in a large scale. The common structural features of S/MAR and pericentromeric (periCEN) TR promotes SAF-A-mediated association with each other. Collectively a model is presented wherein SAF-A/hnRNPU and periCEN TR are the key players in large-scale nuclear organization that supports general transcription.
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Affiliation(s)
- O I Podgornaya
- Institute of Cytology RAS, St. Petersburg State University, Russia.
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7
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Nickerson JA. The ribonucleoprotein network of the nucleus: a historical perspective. Curr Opin Genet Dev 2022; 75:101940. [PMID: 35777349 DOI: 10.1016/j.gde.2022.101940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 05/16/2022] [Accepted: 05/24/2022] [Indexed: 11/28/2022]
Abstract
There is a long experimental history supporting the principle that RNA is essential for normal nuclear and chromatin architecture. Most of the genome is transcribed into RNA but only 2% of the sequence codes for proteins. In the nucleus, most non-coding RNA, packaged in proteins, is bound into structures including chromatin and a non-chromatin scaffolding, the nuclear matrix, which was first observed by electron microscopy. Removing nuclear RNA or inhibiting its transcription causes the condensation of chromatin, showing the importance of RNA in spatially and functionally organizing the genome. Today, powerful techniques for the molecular characterization of RNA and for mapping its spatial organization in the nucleus have provided molecular detail to these principles.
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Affiliation(s)
- Jeffrey A Nickerson
- Division of Genes & Development, Department of Pediatrics, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.
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8
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Abstract
It has long been proposed that nuclear RNAs might play an important role in organizing the structure of the nucleus. Initial experiments performed more than 30 years ago found that global disruption of RNA led to visible rearrangements of nuclear organization. Yet, this idea remained controversial for many years, in large part because it was unclear what specific RNAs might be involved, and which specific nuclear structures might be dependent on RNA. Over the past few years, the contributions of RNA to organizing nuclear structures have become clearer with the discovery that many nuclear bodies are enriched for specific noncoding RNAs (ncRNAs); in specific cases, ncRNAs have been shown to be essential for establishment and maintenance of these nuclear structures. More recently, many different ncRNAs have been shown to play critical roles in initiating the three-dimensional (3D) spatial organization of DNA, RNA, and protein molecules in the nucleus. These examples, combined with global imaging and genomic experiments, have begun to paint a picture of a broader role for RNA in nuclear organization and to uncover a unifying mechanism that may explain why RNA is a uniquely suited molecule for this role. In this review, we provide an overview of the history of RNA and nuclear structure and discuss key examples of RNA-mediated bodies, the global roles of ncRNAs in shaping nuclear structure, and emerging insights into mechanisms of RNA-mediated nuclear organization.
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Affiliation(s)
- Sofia A Quinodoz
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Mitchell Guttman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA
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9
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Kejnovsky E, Jedlicka P. Nucleic acids movement and its relation to genome dynamics of repetitive DNA: Is cellular and intercellular movement of DNA and RNA molecules related to the evolutionary dynamic genome components?: Is cellular and intercellular movement of DNA and RNA molecules related to the evolutionary dynamic genome components? Bioessays 2022; 44:e2100242. [PMID: 35112737 DOI: 10.1002/bies.202100242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/13/2022] [Accepted: 01/17/2022] [Indexed: 11/07/2022]
Abstract
There is growing evidence of evolutionary genome plasticity. The evolution of repetitive DNA elements, the major components of most eukaryotic genomes, involves the amplification of various classes of mobile genetic elements, the expansion of satellite DNA, the transfer of fragments or entire organellar genomes and may have connections with viruses. In addition to various repetitive DNA elements, a plethora of large and small RNAs migrate within and between cells during individual development as well as during evolution and contribute to changes of genome structure and function. Such migration of DNA and RNA molecules often results in horizontal gene transfer, thus shaping the whole genomic network of interconnected species. Here, we propose that a high evolutionary dynamism of repetitive genome components is often related to the migration/movement of DNA or RNA molecules. We speculate that the cytoplasm is probably an ideal compartment for such evolutionary experiments.
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Affiliation(s)
- Eduard Kejnovsky
- Department of Plant Developmental Genetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Pavel Jedlicka
- Department of Plant Developmental Genetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
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10
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Loureiro JR, Castro AF, Figueiredo AS, Silveira I. Molecular Mechanisms in Pentanucleotide Repeat Diseases. Cells 2022; 11:cells11020205. [PMID: 35053321 PMCID: PMC8773600 DOI: 10.3390/cells11020205] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 02/01/2023] Open
Abstract
The number of neurodegenerative diseases resulting from repeat expansion has increased extraordinarily in recent years. In several of these pathologies, the repeat can be transcribed in RNA from both DNA strands producing, at least, one toxic RNA repeat that causes neurodegeneration by a complex mechanism. Recently, seven diseases have been found caused by a novel intronic pentanucleotide repeat in distinct genes encoding proteins highly expressed in the cerebellum. These disorders are clinically heterogeneous being characterized by impaired motor function, resulting from ataxia or epilepsy. The role that apparently normal proteins from these mutant genes play in these pathologies is not known. However, recent advances in previously known spinocerebellar ataxias originated by abnormal non-coding pentanucleotide repeats point to a gain of a toxic function by the pathogenic repeat-containing RNA that abnormally forms nuclear foci with RNA-binding proteins. In cells, RNA foci have been shown to be formed by phase separation. Moreover, the field of repeat expansions has lately achieved an extraordinary progress with the discovery that RNA repeats, polyglutamine, and polyalanine proteins are crucial for the formation of nuclear membraneless organelles by phase separation, which is perturbed when they are expanded. This review will cover the amazing advances on repeat diseases.
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Affiliation(s)
- Joana R. Loureiro
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana F. Castro
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Ana S. Figueiredo
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Isabel Silveira
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Correspondence: ; Tel.: +351-2240-8800
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11
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Zhang X, Wang T. Plant 3D Chromatin Organization: Important Insights from Chromosome Conformation Capture Analyses of the Last 10 Years. PLANT & CELL PHYSIOLOGY 2021; 62:1648-1661. [PMID: 34486654 PMCID: PMC8664644 DOI: 10.1093/pcp/pcab134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/25/2021] [Accepted: 09/01/2021] [Indexed: 05/05/2023]
Abstract
Over the past few decades, eukaryotic linear genomes and epigenomes have been widely and extensively studied for understanding gene expression regulation. More recently, the three-dimensional (3D) chromatin organization was found to be important for determining genome functionality, finely tuning physiological processes for appropriate cellular responses. With the development of visualization techniques and chromatin conformation capture (3C)-based techniques, increasing evidence indicates that chromosomal architecture characteristics and chromatin domains with different epigenetic modifications in the nucleus are correlated with transcriptional activities. Subsequent studies have further explored the intricate interplay between 3D genome organization and the function of interacting regions. In this review, we summarize spatial distribution patterns of chromatin, including chromatin positioning, configurations and domains, with a particular focus on the effect of a unique form of interaction between varieties of factors that shape the 3D genome conformation in plants. We further discuss the methods, advantages and limitations of various 3C-based techniques, highlighting the applications of these technologies in plants to identify chromatin domains, and address their dynamic changes and functional implications in evolution, and adaptation to development and changing environmental conditions. Moreover, the future implications and emerging research directions of 3D genome organization are discussed.
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Affiliation(s)
- Xinxin Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences and School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, P. R. China
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, P. R. China
| | - Tianzuo Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, P. R. China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100093, P. R. China
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12
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Marenda M, Lazarova E, Gilbert N. The role of SAF-A/hnRNP U in regulating chromatin structure. Curr Opin Genet Dev 2021; 72:38-44. [PMID: 34823151 DOI: 10.1016/j.gde.2021.10.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 10/15/2021] [Accepted: 10/27/2021] [Indexed: 01/01/2023]
Abstract
Scaffold attachment factor A (SAF-A) or hnRNP U is a nuclear RNA-binding protein with a well-documented role in processing newly transcribed RNA. Recent studies also indicate that SAF-A can oligomerise in an ATP-dependent manner and interact with RNA to form a dynamic nuclear mesh. This mesh is thought to regulate nuclear and chromatin architecture, yet a mechanistic understanding is lacking. Here, we review developments in the field to understand how the SAF-A/RNA mesh affects chromatin organisation in interphase and mitosis. As SAF-A has an intrinsically disordered domain we discuss how the chromatin mesh is related to nuclear phase-separated condensates, which in other situations have been shown to regulate transcription and cell functions. Finally, we infer possible links between diseases emerging from SAF-A mutations and its role in chromatin organisation and regulation.
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Affiliation(s)
- Mattia Marenda
- Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Elena Lazarova
- Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Nick Gilbert
- Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK.
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13
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Trigiante G, Blanes Ruiz N, Cerase A. Emerging Roles of Repetitive and Repeat-Containing RNA in Nuclear and Chromatin Organization and Gene Expression. Front Cell Dev Biol 2021; 9:735527. [PMID: 34722514 PMCID: PMC8552494 DOI: 10.3389/fcell.2021.735527] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 09/09/2021] [Indexed: 12/14/2022] Open
Abstract
Genomic repeats have been intensely studied as regulatory elements controlling gene transcription, splicing and genome architecture. Our understanding of the role of the repetitive RNA such as the RNA coming from genomic repeats, or repetitive sequences embedded in mRNA/lncRNAs, in nuclear and cellular functions is instead still limited. In this review we discuss evidence supporting the multifaceted roles of repetitive RNA and RNA binding proteins in nuclear organization, gene regulation, and in the formation of dynamic membrane-less aggregates. We hope that our review will further stimulate research in the consolidating field of repetitive RNA biology.
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Affiliation(s)
| | | | - Andrea Cerase
- Centre for Genomics and Child Health, Barts and The London School of Medicine and Dentistry, Blizard Institute, Queen Mary University of London, London, United Kingdom
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14
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Marenda M, Lazarova E, van de Linde S, Gilbert N, Michieletto D. Parameter-free molecular super-structures quantification in single-molecule localization microscopy. J Cell Biol 2021; 220:211893. [PMID: 33734291 PMCID: PMC7980255 DOI: 10.1083/jcb.202010003] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/06/2021] [Accepted: 02/23/2021] [Indexed: 12/18/2022] Open
Abstract
Understanding biological function requires the identification and characterization of complex patterns of molecules. Single-molecule localization microscopy (SMLM) can quantitatively measure molecular components and interactions at resolutions far beyond the diffraction limit, but this information is only useful if these patterns can be quantified and interpreted. We provide a new approach for the analysis of SMLM data that develops the concept of structures and super-structures formed by interconnected elements, such as smaller protein clusters. Using a formal framework and a parameter-free algorithm, (super-)structures formed from smaller components are found to be abundant in classes of nuclear proteins, such as heterogeneous nuclear ribonucleoprotein particles (hnRNPs), but are absent from ceramides located in the plasma membrane. We suggest that mesoscopic structures formed by interconnected protein clusters are common within the nucleus and have an important role in the organization and function of the genome. Our algorithm, SuperStructure, can be used to analyze and explore complex SMLM data and extract functionally relevant information.
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Affiliation(s)
- Mattia Marenda
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK.,Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Elena Lazarova
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Sebastian van de Linde
- Scottish Universities Physics Alliance, Department of Physics, University of Strathclyde, Glasgow, UK
| | - Nick Gilbert
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Davide Michieletto
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK.,Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
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15
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Bylino OV, Ibragimov AN, Pravednikova AE, Shidlovskii YV. Investigation of the Basic Steps in the Chromosome Conformation Capture Procedure. Front Genet 2021; 12:733937. [PMID: 34616432 PMCID: PMC8488379 DOI: 10.3389/fgene.2021.733937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/16/2021] [Indexed: 12/05/2022] Open
Abstract
A constellation of chromosome conformation capture methods (С-methods) are an important tool for biochemical analysis of the spatial interactions between DNA regions that are separated in the primary sequence. All these methods are based on the long sequence of basic steps of treating cells, nuclei, chromatin, and finally DNA, thus representing a significant technical challenge. Here, we present an in-depth study of the basic steps in the chromatin conformation capture procedure (3С), which was performed using Drosophila Schneider 2 cells as a model. We investigated the steps of cell lysis, nuclei washing, nucleoplasm extraction, chromatin treatment with SDS/Triton X-100, restriction enzyme digestion, chromatin ligation, reversion of cross-links, DNA extraction, treatment of a 3C library with RNases, and purification of the 3C library. Several options were studied, and optimal conditions were found. Our work contributes to the understanding of the 3C basic steps and provides a useful guide to the 3C procedure.
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Affiliation(s)
- Oleg V. Bylino
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Airat N. Ibragimov
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Anna E. Pravednikova
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Yulii V. Shidlovskii
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- Department of Biology and General Genetics, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
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16
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RNA m 6A modification orchestrates a LINE-1-host interaction that facilitates retrotransposition and contributes to long gene vulnerability. Cell Res 2021; 31:861-885. [PMID: 34108665 PMCID: PMC8324889 DOI: 10.1038/s41422-021-00515-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 04/27/2021] [Indexed: 02/06/2023] Open
Abstract
The molecular basis underlying the interaction between retrotransposable elements (RTEs) and the human genome remains poorly understood. Here, we profiled N6-methyladenosine (m6A) deposition on nascent RNAs in human cells by developing a new method MINT-Seq, which revealed that many classes of RTE RNAs, particularly intronic LINE-1s (L1s), are strongly methylated. These m6A-marked intronic L1s (MILs) are evolutionarily young, sense-oriented to hosting genes, and are bound by a dozen RNA binding proteins (RBPs) that are putative novel readers of m6A-modified RNAs, including a nuclear matrix protein SAFB. Notably, m6A positively controls the expression of both autonomous L1s and co-transcribed L1 relics, promoting L1 retrotransposition. We showed that MILs preferentially reside in long genes with critical roles in DNA damage repair and sometimes in L1 suppression per se, where they act as transcriptional "roadblocks" to impede the hosting gene expression, revealing a novel host-weakening strategy by the L1s. In counteraction, the host uses the SAFB reader complex to bind m6A-L1s to reduce their levels, and to safeguard hosting gene transcription. Remarkably, our analysis identified thousands of MILs in multiple human fetal tissues, enlisting them as a novel category of cell-type-specific regulatory elements that often compromise transcription of long genes and confer their vulnerability in neurodevelopmental disorders. We propose that this m6A-orchestrated L1-host interaction plays widespread roles in gene regulation, genome integrity, human development and diseases.
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17
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Creamer KM, Kolpa HJ, Lawrence JB. Nascent RNA scaffolds contribute to chromosome territory architecture and counter chromatin compaction. Mol Cell 2021; 81:3509-3525.e5. [PMID: 34320406 DOI: 10.1016/j.molcel.2021.07.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 07/06/2021] [Accepted: 07/06/2021] [Indexed: 12/17/2022]
Abstract
Nuclear chromosomes transcribe far more RNA than required to encode protein. Here we investigate whether non-coding RNA broadly contributes to cytological-scale chromosome territory architecture. We develop a procedure that depletes soluble proteins, chromatin, and most nuclear RNA from the nucleus but does not delocalize XIST, a known architectural RNA, from an insoluble chromosome "scaffold." RNA-seq analysis reveals that most RNA in the nuclear scaffold is repeat-rich, non-coding, and derived predominantly from introns of nascent transcripts. Insoluble, repeat-rich (C0T-1) RNA co-distributes with known scaffold proteins including scaffold attachment factor A (SAF-A), and distribution of these components inversely correlates with chromatin compaction in normal and experimentally manipulated nuclei. We further show that RNA is required for SAF-A to interact with chromatin and for enrichment of structurally embedded "scaffold attachment regions" prevalent in euchromatin. Collectively, the results indicate that long nascent transcripts contribute a dynamic structural role that promotes the open architecture of active chromosome territories.
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Affiliation(s)
- Kevin Michael Creamer
- Department of Neurology and Pediatrics, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | - Heather Jill Kolpa
- Department of Neurology and Pediatrics, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | - Jeanne Bentley Lawrence
- Department of Neurology and Pediatrics, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.
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18
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Marenda M, Lazarova E, van de Linde S, Gilbert N, Michieletto D. Parameter-free molecular super-structures quantification in single-molecule localization microscopy. J Cell Biol 2021. [PMID: 33734291 DOI: 10.1101/2020.08.19.254540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
Abstract
Understanding biological function requires the identification and characterization of complex patterns of molecules. Single-molecule localization microscopy (SMLM) can quantitatively measure molecular components and interactions at resolutions far beyond the diffraction limit, but this information is only useful if these patterns can be quantified and interpreted. We provide a new approach for the analysis of SMLM data that develops the concept of structures and super-structures formed by interconnected elements, such as smaller protein clusters. Using a formal framework and a parameter-free algorithm, (super-)structures formed from smaller components are found to be abundant in classes of nuclear proteins, such as heterogeneous nuclear ribonucleoprotein particles (hnRNPs), but are absent from ceramides located in the plasma membrane. We suggest that mesoscopic structures formed by interconnected protein clusters are common within the nucleus and have an important role in the organization and function of the genome. Our algorithm, SuperStructure, can be used to analyze and explore complex SMLM data and extract functionally relevant information.
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Affiliation(s)
- Mattia Marenda
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Elena Lazarova
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Sebastian van de Linde
- Scottish Universities Physics Alliance, Department of Physics, University of Strathclyde, Glasgow, UK
| | - Nick Gilbert
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Davide Michieletto
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
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19
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Smith KP, Hall LL, Lawrence JB. Nuclear hubs built on RNAs and clustered organization of the genome. Curr Opin Cell Biol 2020; 64:67-76. [PMID: 32259767 DOI: 10.1016/j.ceb.2020.02.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/13/2020] [Accepted: 02/22/2020] [Indexed: 12/18/2022]
Abstract
RNAs play diverse roles in formation and function of subnuclear compartments, most of which are associated with active genes. NEAT1 and NEAT2/MALAT1 exemplify long non-coding RNAs (lncRNAs) known to function in nuclear bodies; however, we suggest that RNA biogenesis itself may underpin much nuclear compartmentalization. Recent studies show that active genes cluster with nuclear speckles on a genome-wide scale, significantly advancing earlier cytological evidence that speckles (aka SC-35 domains) are hubs of concentrated pre-mRNA metabolism. We propose the 'karyotype to hub' hypothesis to explain this organization: clustering of genes in the human karyotype may have evolved to facilitate the formation of efficient nuclear hubs, driven in part by the propensity of ribonucleoproteins (RNPs) to form large-scale condensates. The special capacity of highly repetitive RNAs to impact architecture is highlighted by recent findings that human satellite II RNA sequesters factors into abnormal nuclear bodies in disease, potentially co-opting a normal developmental mechanism.
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Affiliation(s)
- Kelly P Smith
- Department of Neurology, University of Massachusetts Medical School, 55 Lake Ave. North, Worcester, MA, 01655, USA
| | - Lisa L Hall
- Department of Neurology, University of Massachusetts Medical School, 55 Lake Ave. North, Worcester, MA, 01655, USA
| | - Jeanne B Lawrence
- Department of Neurology, University of Massachusetts Medical School, 55 Lake Ave. North, Worcester, MA, 01655, USA.
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20
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O'Neill RJ. Seq'ing identity and function in a repeat-derived noncoding RNA world. Chromosome Res 2020; 28:111-127. [PMID: 32146545 PMCID: PMC7393779 DOI: 10.1007/s10577-020-09628-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/07/2020] [Accepted: 02/14/2020] [Indexed: 01/06/2023]
Abstract
Innovations in high-throughout sequencing approaches are being marshaled to both reveal the composition of the abundant and heterogeneous noncoding RNAs that populate cell nuclei and lend insight to the mechanisms by which noncoding RNAs influence chromosome biology and gene expression. This review focuses on some of the recent technological developments that have enabled the isolation of nascent transcripts and chromatin-associated and DNA-interacting RNAs. Coupled with emerging genome assembly and analytical approaches, the field is poised to achieve a comprehensive catalog of nuclear noncoding RNAs, including those derived from repetitive regions within eukaryotic genomes. Herein, particular attention is paid to the challenges and advances in the sequence analyses of repeat and transposable element-derived noncoding RNAs and in ascribing specific function(s) to such RNAs.
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Affiliation(s)
- Rachel J O'Neill
- Institute for Systems Genomics, University of Connecticut, Storrs, CT, 06269, USA.
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, 06269, USA.
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT, 06030, USA.
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21
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Matsuno Y, Yamashita T, Wagatsuma M, Yamakage H. Convergence in LINE-1 nucleotide variations can benefit redundantly forming triplexes with lncRNA in mammalian X-chromosome inactivation. Mob DNA 2019; 10:33. [PMID: 31384315 PMCID: PMC6664574 DOI: 10.1186/s13100-019-0173-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 07/08/2019] [Indexed: 01/01/2023] Open
Abstract
Background Associations between X-inactive transcript (Xist)–long noncoding RNA (lncRNA) and chromatin are critical intermolecular interactions in the X-chromosome inactivation (XCI) process. Despite high-resolution analyses of the Xist RNA-binding sites, specific interaction sequences are yet to be identified. Based on elusive features of the association between Xist RNA and chromatin and the possible existence of multiple low-affinity binding sites in Xist RNA, we defined short motifs (≥5 nucleotides), termed as redundant UC/TC (r-UC/TC) or AG (r-AG) motifs, which may help in the mediation of triplex formation between the lncRNAs and duplex DNA. Results The study showed that r-UC motifs are densely dispersed throughout mouse and human Xist/XIST RNAs, whereas r-AG motifs are even more densely dispersed along opossum RNA-on-the-silent X (Rsx) RNA, and also along both full-length and truncated long interspersed nuclear elements (LINE-1s, L1s) of the three species. Predicted secondary structures of the lncRNAs showed that the length range of these sequence motifs available for forming triplexes was even shorter, mainly 5- to 9-nucleotides long. Quartz crystal microbalance (QCM) measurements and Monte Carlo (MC) simulations indicated that minimum-length motifs can reinforce the binding state by increasing the copy number of the motifs in the same RNA or DNA molecule. Further, r-AG motifs in L1s had a similar length-distribution pattern, regardless of the similarities in the length or sequence of L1s across the three species; this also applies to high-frequency mutations in r-AG motifs, which suggests convergence in L1 sequence variations. Conclusions Multiple short motifs in both RNA and duplex DNA molecules could be brought together to form triplexes with either Hoogsteen or reverse Hoogsteen hydrogen bonding, by which their associations are cooperatively enhanced. This novel triplex interaction could be involved in associations between lncRNA and chromatin in XCI, particularly at the sites of L1s. Potential binding of Xist/XIST/Rsx RNAs specifically at L1s is most likely preserved through the r-AG motifs conserved in mammalian L1s through convergence in L1 nucleotide variations and by maintaining a particular r-UC/r-AG motif ratio in each of these lncRNAs, irrespective of their poorly conserved sequences. Electronic supplementary material The online version of this article (10.1186/s13100-019-0173-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yoko Matsuno
- 1Division of Clinical Preventive Medicine, Niigata University, Niigata, Japan
| | - Takefumi Yamashita
- 2Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
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22
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Michieletto D, Gilbert N. Role of nuclear RNA in regulating chromatin structure and transcription. Curr Opin Cell Biol 2019; 58:120-125. [PMID: 31009871 PMCID: PMC6694202 DOI: 10.1016/j.ceb.2019.03.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/10/2019] [Accepted: 03/13/2019] [Indexed: 12/31/2022]
Abstract
The importance of three-dimensional chromatin organisation in genome regulation has never been clearer. But in spite of the enormous technological advances to probe chromatin organisation in vivo, there is still a lack of mechanistic understanding of how such an arrangement is achieved. Here we review emerging evidence pointing to an intriguing role of nuclear RNA in shaping large-scale chromatin structure and regulating genome function. We suggest this role may be achieved through the formation of a dynamic nuclear mesh that can exploit ATP-driven processes and phase separation of RNA-binding proteins to tune its assembly and material properties.
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Affiliation(s)
- Davide Michieletto
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK; School of Physics and Astronomy, University of Edinburgh, EH9 3FD, UK
| | - Nick Gilbert
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK.
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23
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Nozawa RS, Gilbert N. RNA: Nuclear Glue for Folding the Genome. Trends Cell Biol 2019; 29:201-211. [DOI: 10.1016/j.tcb.2018.12.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 12/10/2018] [Accepted: 12/14/2018] [Indexed: 12/20/2022]
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24
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Doğan ES, Liu C. Three-dimensional chromatin packing and positioning of plant genomes. NATURE PLANTS 2018; 4:521-529. [PMID: 30061747 DOI: 10.1038/s41477-018-0199-5] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 06/04/2018] [Accepted: 06/11/2018] [Indexed: 05/18/2023]
Abstract
Information and function of a genome are not only decorated with epigenetic marks in the linear DNA sequence but also in their non-random spatial organization in the nucleus. Recent research has revealed that three-dimensional (3D) chromatin organization is highly correlated with the functionality of the genome, contributing to many cellular processes. Driven by the improvements in chromatin conformation capture methods and visualization techniques, the past decade has been an exciting period for the study of plants' 3D genome structures, and our knowledge in this area has been substantially advanced. This Review describes our current understanding of plant chromatin organization and positioning beyond the nucleosomal level, and discusses future directions.
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Affiliation(s)
- Ezgi Süheyla Doğan
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Chang Liu
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany.
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25
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Ilic A, Lu S, Bhatia V, Begum F, Klonisch T, Agarwal P, Xu W, Davie JR. Ubiquitin C-terminal hydrolase isozyme L1 is associated with shelterin complex at interstitial telomeric sites. Epigenetics Chromatin 2017; 10:54. [PMID: 29126443 PMCID: PMC5681776 DOI: 10.1186/s13072-017-0160-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 10/31/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ubiquitin C-terminal hydrolase isozyme L1 (UCHL1) is primarily expressed in neuronal cells and neuroendocrine cells and has been associated with various diseases, including many cancers. It is a multifunctional protein involved in deubiquitination, ubiquitination and ubiquitin homeostasis, but its specific roles are disputed and still generally undetermined. RESULTS Herein, we demonstrate that UCHL1 is associated with genomic DNA in certain prostate cancer cell lines, including DU 145 cells derived from a brain metastatic site, and in HEK293T embryonic kidney cells with a neuronal lineage. Chromatin immunoprecipitation and sequencing revealed that UCHL1 localizes to TTAGGG repeats at telomeres and interstitial telomeric sequences, as do TRF1 and TRF2, components of the shelterin complex. A weak or transient interaction between UCHL1 and the shelterin complex was confirmed by immunoprecipitation and proximity ligation assays. UCHL1 and RAP1, also known as TERF2IP and a component of the shelterin complex, were bound to the nuclear scaffold. CONCLUSIONS We demonstrated a novel feature of UCHL1 in binding telomeres and interstitial telomeric sites.
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Affiliation(s)
- Aleksandar Ilic
- Children's Hospital Research Institute of Manitoba, University of Manitoba, 715 McDermot Avenue, Room 600A, Winnipeg, MB, R3E 3P4, Canada
| | - Sumin Lu
- Children's Hospital Research Institute of Manitoba, University of Manitoba, 715 McDermot Avenue, Room 600A, Winnipeg, MB, R3E 3P4, Canada
| | - Vikram Bhatia
- Children's Hospital Research Institute of Manitoba, University of Manitoba, 715 McDermot Avenue, Room 600A, Winnipeg, MB, R3E 3P4, Canada
| | - Farhana Begum
- Department of Human Anatomy and Cell Science, University of Manitoba, 130-745 Bannatyne Ave, Winnipeg, MB, R3E 0J9, Canada
| | - Thomas Klonisch
- Department of Human Anatomy and Cell Science, University of Manitoba, 130-745 Bannatyne Ave, Winnipeg, MB, R3E 0J9, Canada
| | - Prasoon Agarwal
- Children's Hospital Research Institute of Manitoba, University of Manitoba, 715 McDermot Avenue, Room 600A, Winnipeg, MB, R3E 3P4, Canada
| | - Wayne Xu
- Children's Hospital Research Institute of Manitoba, University of Manitoba, 715 McDermot Avenue, Room 600A, Winnipeg, MB, R3E 3P4, Canada
| | - James R Davie
- Children's Hospital Research Institute of Manitoba, University of Manitoba, 715 McDermot Avenue, Room 600A, Winnipeg, MB, R3E 3P4, Canada.
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26
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Creamer KM, Lawrence JB. XIST RNA: a window into the broader role of RNA in nuclear chromosome architecture. Philos Trans R Soc Lond B Biol Sci 2017; 372:20160360. [PMID: 28947659 PMCID: PMC5627162 DOI: 10.1098/rstb.2016.0360] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2017] [Indexed: 12/31/2022] Open
Abstract
XIST RNA triggers the transformation of an active X chromosome into a condensed, inactive Barr body and therefore provides a unique window into transitions of higher-order chromosome architecture. Despite recent progress, how XIST RNA localizes and interacts with the X chromosome remains poorly understood. Genetic engineering of XIST into a trisomic autosome demonstrates remarkable capacity of XIST RNA to localize and comprehensively silence that autosome. Thus, XIST does not require X chromosome-specific sequences but operates on mechanisms available genome-wide. Prior results suggested XIST localization is controlled by attachment to the insoluble nuclear scaffold. Our recent work affirms that scaffold attachment factor A (SAF-A) is involved in anchoring XIST, but argues against the view that SAF-A provides a unimolecular bridge between RNA and the chromosome. Rather, we suggest that a complex meshwork of architectural proteins interact with XIST RNA. Parallel work studying the territory of actively transcribed chromosomes suggests that repeat-rich RNA 'coats' euchromatin and may impact chromosome architecture in a manner opposite of XIST A model is discussed whereby RNA may not just recruit histone modifications, but more directly impact higher-order chromatin condensation via interaction with architectural proteins of the nucleus.This article is part of the themed issue 'X-chromosome inactivation: a tribute to Mary Lyon'.
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Affiliation(s)
- K M Creamer
- Department of Neurology and Pediatrics, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - J B Lawrence
- Department of Neurology and Pediatrics, University of Massachusetts Medical School, Worcester, MA 01655, USA
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27
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Nozawa RS, Boteva L, Soares DC, Naughton C, Dun AR, Buckle A, Ramsahoye B, Bruton PC, Saleeb RS, Arnedo M, Hill B, Duncan RR, Maciver SK, Gilbert N. SAF-A Regulates Interphase Chromosome Structure through Oligomerization with Chromatin-Associated RNAs. Cell 2017. [PMID: 28622508 PMCID: PMC5473940 DOI: 10.1016/j.cell.2017.05.029] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Higher eukaryotic chromosomes are organized into topologically constrained functional domains; however, the molecular mechanisms required to sustain these complex interphase chromatin structures are unknown. A stable matrix underpinning nuclear organization was hypothesized, but the idea was abandoned as more dynamic models of chromatin behavior became prevalent. Here, we report that scaffold attachment factor A (SAF-A), originally identified as a structural nuclear protein, interacts with chromatin-associated RNAs (caRNAs) via its RGG domain to regulate human interphase chromatin structures in a transcription-dependent manner. Mechanistically, this is dependent on SAF-A's AAA+ ATPase domain, which mediates cycles of protein oligomerization with caRNAs, in response to ATP binding and hydrolysis. SAF-A oligomerization decompacts large-scale chromatin structure while SAF-A loss or monomerization promotes aberrant chromosome folding and accumulation of genome damage. Our results show that SAF-A and caRNAs form a dynamic, transcriptionally responsive chromatin mesh that organizes large-scale chromosome structures and protects the genome from instability.
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Affiliation(s)
- Ryu-Suke Nozawa
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Lora Boteva
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Dinesh C Soares
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Catherine Naughton
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Alison R Dun
- Edinburgh Super-Resolution Imaging Consortium, Institute of Biological Chemistry, Biophysics, and Bioengineering, Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Adam Buckle
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Bernard Ramsahoye
- Centre for Genomics and Experimental Medicine, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Peter C Bruton
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Rebecca S Saleeb
- Edinburgh Super-Resolution Imaging Consortium, Institute of Biological Chemistry, Biophysics, and Bioengineering, Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Maria Arnedo
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Bill Hill
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Rory R Duncan
- Edinburgh Super-Resolution Imaging Consortium, Institute of Biological Chemistry, Biophysics, and Bioengineering, Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Sutherland K Maciver
- Centre for Integrative Physiology, Edinburgh Medical School, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - Nick Gilbert
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK.
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28
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Naderlinger E, Holzmann K. Epigenetic Regulation of Telomere Maintenance for Therapeutic Interventions in Gliomas. Genes (Basel) 2017; 8:E145. [PMID: 28513547 PMCID: PMC5448019 DOI: 10.3390/genes8050145] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/08/2017] [Accepted: 05/12/2017] [Indexed: 02/07/2023] Open
Abstract
High-grade astrocytoma of WHO grade 4 termed glioblastoma multiforme (GBM) is a common human brain tumor with poor patient outcome. Astrocytoma demonstrates two known telomere maintenance mechanisms (TMMs) based on telomerase activity (TA) and on alternative lengthening of telomeres (ALT). ALT is associated with lower tumor grades and better outcome. In contrast to ALT, regulation of TA in tumors by direct mutation and epigenetic activation of the hTERT promoter is well established. Here, we summarize the genetic background of TMMs in non-malignant cells and in cancer, in addition to clinical and pathological features of gliomas. Furthermore, we present new evidence for epigenetic mechanisms (EMs) involved in regulation of ALT and TA with special emphasis on human diffuse gliomas as potential therapeutic drug targets. We discuss the role of TMM associated telomeric chromatin factors such as DNA and histone modifying enzymes and non-coding RNAs including microRNAs and long telomeric TERRA transcripts.
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Affiliation(s)
- Elisabeth Naderlinger
- Institute of Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna 1090, Austria.
| | - Klaus Holzmann
- Institute of Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna 1090, Austria.
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