1
|
Bermudez A, Latham ZD, Ma AJ, Bi D, Hu JK, Lin NYC. Regulation of Chromatin Modifications through Coordination of Nucleus Size and Epithelial Cell Morphology Heterogeneity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.18.590164. [PMID: 38712099 PMCID: PMC11071433 DOI: 10.1101/2024.04.18.590164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Cell morphology heterogeneity within epithelial collectives is a pervasive phenomenon intertwined with tissue mechanical properties. Despite its widespread occurrence, the underlying mechanisms driving cell morphology heterogeneity and its consequential biological ramifications remain elusive. Here, we investigate the dynamic evolution of epithelial cell morphology and nucleus morphology during crowding, unveiling a consistent correlation between the two. Our investigation reveals a persistent log-normal probability distribution characterizing both cell and nucleus areas across diverse crowding stages and epithelial model systems. We showed that this morphological diversity arises from asymmetric partitioning during cell division and is perpetuated through actomyosin-mediated regulation of cell-nucleus size coordination. Moreover, we provide insights into the impact of nucleus morphology on chromatin dynamics, demonstrating that constraining nucleus area leads to downregulation of the euchromatic mark H3K9ac and upregulation of the heterochromatic mark H3K27me3 through modulation of histone demethylase UTX expression. These findings under-score the significance of cell morphology heterogeneity as a driver of chromatin state diversity, shaping functional variability within epithelial tissues.
Collapse
|
2
|
Marie P, Bazire M, Ladet J, Ameur LB, Chahar S, Fontrodona N, Sexton T, Auboeuf D, Bourgeois CF, Mortreux F. Gene-to-gene coordinated regulation of transcription and alternative splicing by 3D chromatin remodeling upon NF-κB activation. Nucleic Acids Res 2024; 52:1527-1543. [PMID: 38272542 PMCID: PMC10899780 DOI: 10.1093/nar/gkae015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 12/13/2023] [Accepted: 01/05/2024] [Indexed: 01/27/2024] Open
Abstract
The NF-κB protein p65/RelA plays a pivotal role in coordinating gene expression in response to diverse stimuli, including viral infections. At the chromatin level, p65/RelA regulates gene transcription and alternative splicing through promoter enrichment and genomic exon occupancy, respectively. The intricate ways in which p65/RelA simultaneously governs these functions across various genes remain to be fully elucidated. In this study, we employed the HTLV-1 Tax oncoprotein, a potent activator of NF-κB, to investigate its influence on the three-dimensional organization of the genome, a key factor in gene regulation. We discovered that Tax restructures the 3D genomic landscape, bringing together genes based on their regulation and splicing patterns. Notably, we found that the Tax-induced gene-gene contact between the two master genes NFKBIA and RELA is associated with their respective changes in gene expression and alternative splicing. Through dCas9-mediated approaches, we demonstrated that NFKBIA-RELA interaction is required for alternative splicing regulation and is caused by an intragenic enrichment of p65/RelA on RELA. Our findings shed light on new regulatory mechanisms upon HTLV-1 Tax and underscore the integral role of p65/RelA in coordinated regulation of NF-κB-responsive genes at both transcriptional and splicing levels in the context of the 3D genome.
Collapse
Affiliation(s)
- Paul Marie
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Matéo Bazire
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Julien Ladet
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Lamya Ben Ameur
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Sanjay Chahar
- Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| | - Nicolas Fontrodona
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Tom Sexton
- Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| | - Didier Auboeuf
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Cyril F Bourgeois
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Franck Mortreux
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| |
Collapse
|
3
|
Laghmach R, Di Pierro M, Potoyan DA. Four-Dimensional Mesoscale Liquid Model of Nucleus Resolves Chromatin's Radial Organization. PRX LIFE 2024; 2:013006. [PMID: 38601142 PMCID: PMC11005002 DOI: 10.1103/prxlife.2.013006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Recent advances chromatin capture, imaging techniques, and polymer modeling have dramatically enhanced quantitative understanding of chromosomal folding. However, the dynamism inherent in genome architectures due to physical and biochemical forces and their impact on nuclear architecture and cellular functions remains elusive. While imaging of chromatin in four dimensions is becoming more common, there is a conspicuous lack of physics-based computational tools appropriate for revealing the forces that shape nuclear architecture and dynamics. To this end, we have developed a multiphase liquid model of the nucleus, which can resolve chromosomal territories, compartments, and nuclear lamina using a physics-based and data-informed free-energy function. The model enables rapid hypothesis-driven prototyping of nuclear dynamics in four dimensions, thereby facilitating comparison with whole nucleus imaging experiments. As an application, we model the Drosophila nucleus and map phase diagram of various possible nuclear morphologies. We shed light on the interplay of adhesive and cohesive interactions which give rise to distinct radial organization seen in conventional, inverted, and senescent nuclear architectures. The results also show the highly dynamic nature of the radial organization, the disruption of which leads to significant variability in domain coarsening dynamics and consequently variability of chromatin architecture. The model also highlights the impact of oblate nuclear geometry and heterochromatin-subtype interactions on the global chromatin architecture and local asymmetry of chromatin compartments.
Collapse
Affiliation(s)
- Rabia Laghmach
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA
| | - Michele Di Pierro
- Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA
| | - Davit A. Potoyan
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA and Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| |
Collapse
|
4
|
Rossini R, Oshaghi M, Nekrasov M, Bellanger A, Domaschenz R, Dijkwel Y, Abdelhalim M, Collas P, Tremethick D, Paulsen J. Multi-level 3D genome organization deteriorates during breast cancer progression. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.26.568711. [PMID: 38076897 PMCID: PMC10705249 DOI: 10.1101/2023.11.26.568711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Breast cancer entails intricate alterations in genome organization and expression. However, how three-dimensional (3D) chromatin structure changes in the progression from a normal to a breast cancer malignant state remains unknown. To address this, we conducted an analysis combining Hi-C data with lamina-associated domains (LADs), epigenomic marks, and gene expression in an in vitro model of breast cancer progression. Our results reveal that while the fundamental properties of topologically associating domains (TADs) remain largely stable, significant changes occur in the organization of compartments and subcompartments. These changes are closely correlated with alterations in the expression of oncogenic genes. We also observe a restructuring of TAD-TAD interactions, coinciding with a loss of spatial compartmentalization and radial positioning of the 3D genome. Notably, we identify a previously unrecognized interchromosomal insertion event, wherein a locus on chromosome 8 housing the MYC oncogene is inserted into a highly active subcompartment on chromosome 10. This insertion leads to the formation of de novo enhancer contacts and activation of the oncogene, illustrating how structural variants can interact with the 3D genome to drive oncogenic states. In summary, our findings provide evidence for the degradation of genome organization at multiple scales during breast cancer progression revealing novel relationships between genome 3D structure and oncogenic processes.
Collapse
Affiliation(s)
- Roberto Rossini
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
| | - Mohammadsaleh Oshaghi
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
| | - Maxim Nekrasov
- Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Aurélie Bellanger
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0317 Oslo, Norway
| | - Renae Domaschenz
- Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Yasmin Dijkwel
- Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Mohamed Abdelhalim
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0317 Oslo, Norway
| | - Philippe Collas
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0317 Oslo, Norway
- Department of Immunology and Transfusion Medicine, Oslo University Hospital, 0424 Oslo, Norway
| | - David Tremethick
- Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Jonas Paulsen
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
- Centre for Bioinformatics, Department of Informatics, University of Oslo, 0316 Oslo, Norway
| |
Collapse
|
5
|
Zhou B, Xiong Y, Nevo Y, Kahan T, Yakovian O, Alon S, Bhattacharya S, Rosenshine I, Sinai L, Ben-Yehuda S. Dormant bacterial spores encrypt a long-lasting transcriptional program to be executed during revival. Mol Cell 2023; 83:4158-4173.e7. [PMID: 37949068 DOI: 10.1016/j.molcel.2023.10.010] [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: 01/19/2023] [Revised: 08/16/2023] [Accepted: 10/12/2023] [Indexed: 11/12/2023]
Abstract
Sporulating bacteria can retreat into long-lasting dormant spores that preserve the capacity to germinate when propitious. However, how the revival transcriptional program is memorized for years remains elusive. We revealed that in dormant spores, core RNA polymerase (RNAP) resides in a central chromosomal domain, where it remains bound to a subset of intergenic promoter regions. These regions regulate genes encoding for most essential cellular functions, such as rRNAs and tRNAs. Upon awakening, RNAP recruits key transcriptional components, including sigma factor, and progresses to express the adjacent downstream genes. Mutants devoid of spore DNA-compacting proteins exhibit scattered RNAP localization and subsequently disordered firing of gene expression during germination. Accordingly, we propose that the spore chromosome is structured to preserve the transcriptional program by halting RNAP, prepared to execute transcription at the auspicious time. Such a mechanism may sustain long-term transcriptional programs in diverse organisms displaying a quiescent life form.
Collapse
Affiliation(s)
- Bing Zhou
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel
| | - Yifei Xiong
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel
| | - Yuval Nevo
- Info-CORE, Bioinformatics Unit of the I-CORE Computation Center at the Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Tamar Kahan
- Bioinformatics Unit, Faculty of Medicine, The Hebrew University of Jerusalem, 9112001 Jerusalem, Israel
| | - Oren Yakovian
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel; The Racah Institute of Physics, Faculty of Science, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel
| | - Sima Alon
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel
| | - Saurabh Bhattacharya
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel
| | - Ilan Rosenshine
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel
| | - Lior Sinai
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel.
| | - Sigal Ben-Yehuda
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel.
| |
Collapse
|
6
|
Della Chiara G, Jiménez C, Virdi M, Crosetto N, Bienko M. Enhancers dysfunction in the 3D genome of cancer cells. Front Cell Dev Biol 2023; 11:1303862. [PMID: 38020908 PMCID: PMC10657884 DOI: 10.3389/fcell.2023.1303862] [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: 09/28/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Eukaryotic genomes are spatially organized inside the cell nucleus, forming a threedimensional (3D) architecture that allows for spatial separation of nuclear processes and for controlled expression of genes required for cell identity specification and tissue homeostasis. Hence, it is of no surprise that mis-regulation of genome architecture through rearrangements of the linear genome sequence or epigenetic perturbations are often linked to aberrant gene expression programs in tumor cells. Increasing research efforts have shed light into the causes and consequences of alterations of 3D genome organization. In this review, we summarize the current knowledge on how 3D genome architecture is dysregulated in cancer, with a focus on enhancer highjacking events and their contribution to tumorigenesis. Studying the functional effects of genome architecture perturbations on gene expression in cancer offers a unique opportunity for a deeper understanding of tumor biology and sets the basis for the discovery of novel therapeutic targets.
Collapse
Affiliation(s)
| | | | | | - Nicola Crosetto
- Human Technopole, Milan, Italy
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
- Science for Life Laboratory, Solna, Sweden
| | - Magda Bienko
- Human Technopole, Milan, Italy
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
- Science for Life Laboratory, Solna, Sweden
| |
Collapse
|
7
|
Nobari P, Doye V, Boumendil C. Metazoan nuclear pore complexes in gene regulation and genome stability. DNA Repair (Amst) 2023; 130:103565. [PMID: 37696111 DOI: 10.1016/j.dnarep.2023.103565] [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: 05/11/2023] [Revised: 08/28/2023] [Accepted: 08/28/2023] [Indexed: 09/13/2023]
Abstract
The nuclear pore complexes (NPCs), one of the hallmarks of eukaryotic nuclei, allow selective transport of macromolecules between the cytoplasm and the nucleus. Besides this canonical function, an increasing number of additional roles have been attributed to the NPCs and their constituents, the nucleoporins. Here we review recent insights into the mechanisms by which NPCs and nucleoporins affect transcription and DNA repair in metazoans. In the first part, we discuss how gene expression can be affected by the localization of genome-nucleoporin interactions at pores or "off-pores", by the role of nucleoporins in chromatin organization at different scales, or by the physical properties of nucleoporins. In the second part, we review the contribution of NPCs to genome stability, including transport-dependent and -independent functions and the role of positioning at NPCs in the repair of heterochromatic breaks and the regulation of replication stress.
Collapse
Affiliation(s)
- Parisa Nobari
- IGH, Université de Montpellier, CNRS, Montpellier, France
| | - Valérie Doye
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | | |
Collapse
|
8
|
Tiukacheva EA, Ulianov SV, Karpukhina A, Razin SV, Vassetzky Y. 3D genome alterations and editing in pathology. Mol Ther 2023; 31:924-933. [PMID: 36755493 PMCID: PMC10124079 DOI: 10.1016/j.ymthe.2023.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 12/07/2022] [Accepted: 02/03/2023] [Indexed: 02/10/2023] Open
Abstract
The human genome is folded into a multi-level 3D structure that controls many nuclear functions including gene expression. Recently, alterations in 3D genome organization were associated with several genetic diseases and cancer. As a consequence, experimental approaches are now being developed to modify the global 3D genome organization and that of specific loci. Here, we discuss emerging experimental approaches of 3D genome editing that may prove useful in biomedicine.
Collapse
Affiliation(s)
- Eugenia A Tiukacheva
- CNRS UMR9018, Institut Gustave Roussy, 94805 Villejuif, France; Institute of Gene Biology, Moscow 119334, Russia; Moscow Institute of Physics and Technology, Moscow 141700, Russia; Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia; Koltzov Institute of Developmental Biology, Moscow 119334, Russia
| | - Sergey V Ulianov
- Institute of Gene Biology, Moscow 119334, Russia; Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Anna Karpukhina
- CNRS UMR9018, Institut Gustave Roussy, 94805 Villejuif, France; Koltzov Institute of Developmental Biology, Moscow 119334, Russia
| | - Sergey V Razin
- Institute of Gene Biology, Moscow 119334, Russia; Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Yegor Vassetzky
- CNRS UMR9018, Institut Gustave Roussy, 94805 Villejuif, France; Koltzov Institute of Developmental Biology, Moscow 119334, Russia.
| |
Collapse
|
9
|
Bouwman BA, Crosetto N, Bienko M. A GC-centered view of 3D genome organization. Curr Opin Genet Dev 2023; 78:102020. [PMID: 36610373 DOI: 10.1016/j.gde.2022.102020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/30/2022] [Accepted: 12/03/2022] [Indexed: 01/07/2023]
Abstract
In the past two decades, our understanding of how the genome of mammalian cells is spatially organized in the three-dimensional (3D) space of the nucleus and how key nuclear processes are orchestrated in this space has drastically expanded. While genome organization has been extensively studied at the nanoscale, the higher-order arrangement of individual portions of the genome with respect to their intranuclear as well as reciprocal placement is less thoroughly characterized. Emerging evidence points to the existence of a complex radial arrangement of chromatin in the nucleus. However, what shapes this radial organization and whether it has any functional implications remain elusive. In this mini review, we first summarize our current knowledge on this rather overlooked aspect of mammalian genome organization. We then present a theoretical framework for explaining how the genome might be radially organized, focusing on the role of the guanine and cytosine density along the linear genome. Last, we discuss outstanding questions, hoping to inspire future experiments and spark interest in this topic within the 3D genome community.
Collapse
Affiliation(s)
- Britta Am Bouwman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm SE-17165, Sweden; Science for Life Laboratory, Tomtebodavägen 23A, Solna SE-17165, Sweden
| | - Nicola Crosetto
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm SE-17165, Sweden; Science for Life Laboratory, Tomtebodavägen 23A, Solna SE-17165, Sweden; Human Technopole, Viale Rita Levi-Montalcini 1, 20157 Milan, Italy
| | - Magda Bienko
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm SE-17165, Sweden; Science for Life Laboratory, Tomtebodavägen 23A, Solna SE-17165, Sweden; Human Technopole, Viale Rita Levi-Montalcini 1, 20157 Milan, Italy.
| |
Collapse
|
10
|
Finn EH, Misteli T. Nuclear position modulates long-range chromatin interactions. PLoS Genet 2022; 18:e1010451. [PMID: 36206323 PMCID: PMC9581366 DOI: 10.1371/journal.pgen.1010451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/19/2022] [Accepted: 09/28/2022] [Indexed: 11/18/2022] Open
Abstract
The human genome is non-randomly organized within the cell nucleus. Spatial mapping of genome folding by biochemical methods and imaging has revealed extensive variation in locus interaction frequencies between cells in a population and between homologs within an individual cell. Commonly used mapping approaches typically examine either the relative position of genomic sites to each other or the position of individual loci relative to nuclear landmarks. Whether the frequency of specific chromatin-chromatin interactions is affected by where in the nuclear space a locus is located is unknown. Here, we have simultaneously mapped at the single cell level the interaction frequencies and radial position of more than a hundred locus pairs using high-throughput imaging to ask whether the location within the nucleus affects interaction frequency. We find strong enrichment of many interactions at specific radial positions. Position-dependency of interactions was cell-type specific, correlated with local chromatin type, and cell-type-specific enriched associations were marked by increased variability, sometimes without a significant decrease in mean spatial distance. These observations demonstrate that the folding of the chromatin fiber, which brings genomically distant loci into proximity, and the position of that chromatin fiber relative to nuclear landmarks, are closely linked.
Collapse
Affiliation(s)
- Elizabeth H. Finn
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
- * E-mail: (EHF); (TM)
| | - Tom Misteli
- National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (EHF); (TM)
| |
Collapse
|
11
|
Location in the nucleus foretells chromosome anomalies. Nature 2022; 607:454-455. [PMID: 35831567 DOI: 10.1038/d41586-022-01865-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
12
|
Faber GP, Nadav-Eliyahu S, Shav-Tal Y. Nuclear speckles - a driving force in gene expression. J Cell Sci 2022; 135:275909. [PMID: 35788677 DOI: 10.1242/jcs.259594] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Nuclear speckles are dynamic membraneless bodies located in the cell nucleus. They harbor RNAs and proteins, many of which are splicing factors, that together display complex biophysical properties dictating nuclear speckle formation and maintenance. Although these nuclear bodies were discovered decades ago, only recently has in-depth genomic analysis begun to unravel their essential functions in modulation of gene activity. Major advancements in genomic mapping techniques combined with microscopy approaches have enabled insights into the roles nuclear speckles may play in enhancing gene expression, and how gene positioning to specific nuclear landmarks can regulate gene expression and RNA processing. Some studies have drawn a link between nuclear speckles and disease. Certain maladies either involve nuclear speckles directly or dictate the localization and reorganization of many nuclear speckle factors. This is most striking during viral infection, as viruses alter the entire nuclear architecture and highjack host machinery. As discussed in this Review, nuclear speckles represent a fascinating target of study not only to reveal the links between gene positioning, genome subcompartments and gene activity, but also as a potential target for therapeutics.
Collapse
Affiliation(s)
- Gabriel P Faber
- The Mina and Everard Goodman Faculty of Life Sciences , Bar-Ilan University, Ramat Gan 5290002, Israel.,Institute of Nanotechnology , Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Shani Nadav-Eliyahu
- The Mina and Everard Goodman Faculty of Life Sciences , Bar-Ilan University, Ramat Gan 5290002, Israel.,Institute of Nanotechnology , Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Yaron Shav-Tal
- The Mina and Everard Goodman Faculty of Life Sciences , Bar-Ilan University, Ramat Gan 5290002, Israel.,Institute of Nanotechnology , Bar-Ilan University, Ramat Gan 5290002, Israel
| |
Collapse
|
13
|
The era of 3D and spatial genomics. Trends Genet 2022; 38:1062-1075. [PMID: 35680466 DOI: 10.1016/j.tig.2022.05.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 12/28/2022]
Abstract
Over a decade ago the advent of high-throughput chromosome conformation capture (Hi-C) sparked a new era of 3D genomics. Since then the number of methods for mapping the 3D genome has flourished, enabling an ever-increasing understanding of how DNA is packaged in the nucleus and how the spatiotemporal organization of the genome orchestrates its vital functions. More recently, the next generation of spatial genomics technologies has begun to reveal how genome sequence and 3D genome organization vary between cells in their tissue context. We summarize how the toolkit for charting genome topology has evolved over the past decade and discuss how new technological developments are advancing the field of 3D and spatial genomics.
Collapse
|
14
|
Melamed A, Fitzgerald TW, Wang Y, Ma J, Birney E, Bangham CRM. Selective clonal persistence of human retroviruses in vivo: Radial chromatin organization, integration site, and host transcription. SCIENCE ADVANCES 2022; 8:eabm6210. [PMID: 35486737 PMCID: PMC9054021 DOI: 10.1126/sciadv.abm6210] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 03/16/2022] [Indexed: 06/14/2023]
Abstract
The human retroviruses HTLV-1 (human T cell leukemia virus type 1) and HIV-1 persist in vivo as a reservoir of latently infected T cell clones. It is poorly understood what determines which clones survive in the reservoir. We compared >160,000 HTLV-1 integration sites (>40,000 HIV-1 sites) from T cells isolated ex vivo from naturally infected individuals with >230,000 HTLV-1 integration sites (>65,000 HIV-1 sites) from in vitro infection to identify genomic features that determine selective clonal survival. Three statistically independent factors together explained >40% of the observed variance in HTLV-1 clonal survival in vivo: the radial intranuclear position of the provirus, its genomic distance from the centromere, and the intensity of local host genome transcription. The radial intranuclear position of the provirus and its distance from the centromere also explained ~7% of clonal persistence of HIV-1 in vivo. Selection for the intranuclear and intrachromosomal location of the provirus and host transcription intensity favors clonal persistence of human retroviruses in vivo.
Collapse
Affiliation(s)
- Anat Melamed
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, UK
| | | | - Yuchuan Wang
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Jian Ma
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Ewan Birney
- European Bioinformatics Institute (EMBL-EBI), Cambridge, UK
| | - Charles R. M. Bangham
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, UK
| |
Collapse
|
15
|
Rozario AM, Morey A, Elliott C, Russ B, Whelan DR, Turner SJ, Bell TDM. 3D Single Molecule Super-Resolution Microscopy of Whole Nuclear Lamina. Front Chem 2022; 10:863610. [PMID: 35572104 PMCID: PMC9096160 DOI: 10.3389/fchem.2022.863610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/28/2022] [Indexed: 12/02/2022] Open
Abstract
Single molecule (SM) super-resolution microscopies bypass the diffraction limit of conventional optical techniques and provide excellent spatial resolutions in the tens of nanometers without overly complex microscope hardware. SM imaging using optical astigmatism is an efficient strategy for visualizing subcellular features in 3D with a z-range of up to ∼1 µm per acquisition. This approach however, places high demands on fluorophore brightness and photoswitching resilience meaning that imaging entire cell volumes in 3D using SM super-resolution remains challenging. Here we employ SM astigmatism together with multiplane acquisition to visualize the whole nuclear lamina of COS-7 and T cells in 3D. Nuclear lamina provides structural support to the nuclear envelope and participates in vital nuclear functions including internuclear transport, chromatin organization and gene regulation. Its position at the periphery of the nucleus provides a visible reference of the nuclear boundary and can be used to quantify the spatial distribution of intranuclear components such as histone modifications and transcription factors. We found Alexa Fluor 647, a popular photoswitchable fluorophore, remained viable for over an hour of continuous high laser power exposure, and provided sufficient brightness detectable up to 8 µm deep into a cell, allowing us to capture the entire nuclear lamina in 3D. Our approach provides sufficient super-resolution detail of nuclear lamina morphology to enable quantification of overall nuclear dimensions and local membrane features.
Collapse
Affiliation(s)
- Ashley M. Rozario
- School of Chemistry, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
| | - Alison Morey
- Department of Microbiology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
| | - Cade Elliott
- School of Chemistry, Monash University, Clayton, VIC, Australia
| | - Brendan Russ
- Department of Microbiology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
| | - Donna R. Whelan
- La Trobe Institute for Molecular Science, Bendigo, VIC, Australia
| | - Stephen J. Turner
- Department of Microbiology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
- *Correspondence: Stephen J. Turner, ; Toby D. M. Bell,
| | - Toby D. M. Bell
- School of Chemistry, Monash University, Clayton, VIC, Australia
- *Correspondence: Stephen J. Turner, ; Toby D. M. Bell,
| |
Collapse
|
16
|
Tammer L, Hameiri O, Keydar I, Roy VR, Ashkenazy-Titelman A, Custódio N, Sason I, Shayevitch R, Rodríguez-Vaello V, Rino J, Lev Maor G, Leader Y, Khair D, Aiden EL, Elkon R, Irimia M, Sharan R, Shav-Tal Y, Carmo-Fonseca M, Ast G. Gene architecture directs splicing outcome in separate nuclear spatial regions. Mol Cell 2022; 82:1021-1034.e8. [PMID: 35182478 DOI: 10.1016/j.molcel.2022.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 01/31/2022] [Accepted: 01/31/2022] [Indexed: 12/13/2022]
Abstract
How the splicing machinery defines exons or introns as the spliced unit has remained a puzzle for 30 years. Here, we demonstrate that peripheral and central regions of the nucleus harbor genes with two distinct exon-intron GC content architectures that differ in the splicing outcome. Genes with low GC content exons, flanked by long introns with lower GC content, are localized in the periphery, and the exons are defined as the spliced unit. Alternative splicing of these genes results in exon skipping. In contrast, the nuclear center contains genes with a high GC content in the exons and short flanking introns. Most splicing of these genes occurs via intron definition, and aberrant splicing leads to intron retention. We demonstrate that the nuclear periphery and center generate different environments for the regulation of alternative splicing and that two sets of splicing factors form discrete regulatory subnetworks for the two gene architectures. Our study connects 3D genome organization and splicing, thus demonstrating that exon and intron definition modes of splicing occur in different nuclear regions.
Collapse
Affiliation(s)
- Luna Tammer
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Ofir Hameiri
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Ifat Keydar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Vanessa Rachel Roy
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Asaf Ashkenazy-Titelman
- The Mina & Everard Goodman Faculty of Life Sciences and the Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Noélia Custódio
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Itay Sason
- Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ronna Shayevitch
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Victoria Rodríguez-Vaello
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain. Universitat Pompeu Fabra (UPF), Barcelona, Spain, ICREA, Barcelona, Spain
| | - José Rino
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Galit Lev Maor
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Yodfat Leader
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Doha Khair
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Erez Lieberman Aiden
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Manuel Irimia
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain. Universitat Pompeu Fabra (UPF), Barcelona, Spain, ICREA, Barcelona, Spain
| | - Roded Sharan
- Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yaron Shav-Tal
- The Mina & Everard Goodman Faculty of Life Sciences and the Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Maria Carmo-Fonseca
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Gil Ast
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel.
| |
Collapse
|
17
|
RNA gradients: Shapers of 3D genome architecture. Curr Opin Cell Biol 2022; 74:7-12. [PMID: 34998095 DOI: 10.1016/j.ceb.2021.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 01/13/2023]
Abstract
A growing body of evidence points to a role of nuclear RNAs (nucRNAs) in shaping the three-dimensional (3D) architecture of the genome within the nucleus of a eukaryotic cell. nucRNAs are non-homogeneously distributed within the nucleus where they can form global and local gradients that might contribute to instructing the formation and coordinating the function of different types of 3D genome structures. In this article, we highlight the available literature supporting a role of nucRNAs as 3D genome shapers and propose that nucRNA gradients are key mediators of genome structure and function.
Collapse
|
18
|
Knoch TA. How Genomes Emerge, Function, and Evolve: Living Systems Emergence-Genotype-Phenotype-Multilism-Genome/Systems Ecology. Results Probl Cell Differ 2022; 70:103-156. [PMID: 36348106 DOI: 10.1007/978-3-031-06573-6_4] [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] [Indexed: 06/16/2023]
Abstract
What holds together the world in its innermost, what life is, how it emerges, functions, and evolves, has not only been an epic matter of endless romantic sunset poetry and philosophy, but also manifests explicitly in its perhaps most central organization unit-genomes. Their 3D architecture and dynamics, including the interaction networks of regulatory elements, obviously co-evolved as inseparable systems allowing the physical storage, expression, and replication of genetic information. Since we were able to fill finally the much-debated centennial gaps in their 3D architecture and dynamics, now entire new perspectives open beyond epigenetics reaching as far as a general understanding of living systems: besides the previously known DNA double helix and nucleosome structure, the latter compact into a chromatin quasi-fibre folded into stable loops forming stable multi-loop aggregates/rosettes connected by linkers, creating hence the again already known chromosome arms and entire chromosomes forming the cell nucleus. Instantly and for the first time this leads now to a consistent and cross-proven systems statistical mechanics genomics framework elucidating genome intrinsic function and regulation including various components. It balances stability/flexibility ensuring genome integrity, enabling expression/regulation of genetic information, as well as genome replication/spread. Furthermore, genotype and phenotype are multiplisticly entangled being evolutionarily the outcome of both Darwinian natural selection and Lamarckian self-referenced manipulation-all embedded in even broader genome ecology (autopoietic) i(!)n- and environmental scopes. This allows formulating new meta-level functional semantics of genomics, i.e. notions as communication of genes, genomes, and information networks, architectural and dynamic spaces for creativity and innovation, or genomes as central geno-/phenotype entanglements. Beyond and most fundamentally, the paradoxical-seeming local equilibrium substance stability in its entity though far from a universal heat-death-like equilibrium is solved, and system irreversibility, time directionality, and thus the emergence of existence are clarified. Consequently, real deep understandings of genomes, life, and complex systems in general appear in evolutionary perspectives as well as from systems analyses, via system damage/disease (its repair/cure and manipulation) as far as the understanding of extraterrestrial life, the de novo creation and thus artificial life, and even the raison d'etre.
Collapse
Affiliation(s)
- Tobias A Knoch
- Biophysical Genomics, TAKnoch Joined Operations Administrative Office, Mannheim, Germany.
- Human Ecology and Complex Systems, German Society for Human Ecology (DGH), TAKnoch Joined Operations Administrative Office, Mannheim, Germany.
- TAK Renewable Energy UG, TAKnoch Joined Operations Administrative Office, Mannheim, Germany.
| |
Collapse
|
19
|
Hua LL, Casas C, Mikawa T. Mitotic Antipairing of Homologous Chromosomes. Results Probl Cell Differ 2022; 70:191-220. [PMID: 36348108 PMCID: PMC9731508 DOI: 10.1007/978-3-031-06573-6_6] [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
Chromosome organization is highly dynamic and plays an essential role during cell function. It was recently found that pairs of the homologous chromosomes are continuously separated at mitosis and display a haploid (1n) chromosome set, or "antipairing," organization in human cells. Here, we provide an introduction to the current knowledge of homologous antipairing in humans and its implications in human disease.
Collapse
Affiliation(s)
- Lisa L. Hua
- Department of Biology, Sonoma State University, San Francisco
| | - Christian Casas
- Department of Biology, Sonoma State University, San Francisco
| | - Takashi Mikawa
- Department of Anatomy, Cardiovascular Research Institute, University of California, San Francisco,Corresponding author:
| |
Collapse
|
20
|
Cardozo Gizzi AM. A Shift in Paradigms: Spatial Genomics Approaches to Reveal Single-Cell Principles of Genome Organization. Front Genet 2021; 12:780822. [PMID: 34868269 PMCID: PMC8640135 DOI: 10.3389/fgene.2021.780822] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/03/2021] [Indexed: 12/12/2022] Open
Abstract
The genome tridimensional (3D) organization and its role towards the regulation of key cell processes such as transcription is currently a main question in biology. Interphase chromosomes are spatially segregated into "territories," epigenetically-defined large domains of chromatin that interact to form "compartments" with common transcriptional status, and insulator-flanked domains called "topologically associating domains" (TADs). Moreover, chromatin organizes around nuclear structures such as lamina, speckles, or the nucleolus to acquire a higher-order genome organization. Due to recent technological advances, the different hierarchies are being solved. Particularly, advances in microscopy technologies are shedding light on the genome structure at multiple levels. Intriguingly, more and more reports point to high variability and stochasticity at the single-cell level. However, the functional consequences of such variability in genome conformation are still unsolved. Here, I will discuss the implication of the cell-to-cell heterogeneity at the different scales in the context of newly developed imaging approaches, particularly multiplexed Fluorescence in situ hybridization methods that enabled "chromatin tracing." Extensions of these methods are now combining spatial information of dozens to thousands of genomic loci with the localization of nuclear features such as the nucleolus, nuclear speckles, or even histone modifications, creating the fast-moving field of "spatial genomics." As our view of genome organization shifts the focus from ensemble to single-cell, new insights to fundamental questions begin to emerge.
Collapse
Affiliation(s)
- Andres M Cardozo Gizzi
- Centro de Investigación en Medicina Traslacional Severo Amuchastegui (CIMETSA), Instituto Universitario de Ciencias Biomédicas de Córdoba (IUCBC), CONICET, Córdoba, Argentina
| |
Collapse
|
21
|
The Role of Human Satellite III (1q12) Copy Number Variation in the Adaptive Response during Aging, Stress, and Pathology: A Pendulum Model. Genes (Basel) 2021; 12:genes12101524. [PMID: 34680920 PMCID: PMC8535310 DOI: 10.3390/genes12101524] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 09/25/2021] [Accepted: 09/26/2021] [Indexed: 12/18/2022] Open
Abstract
The pericentric satellite III (SatIII or Sat3) and II tandem repeats recently appeared to be transcribed under stress conditions, and the transcripts were shown to play an essential role in the universal stress response. In this paper, we review the role of human-specific SatIII copy number variation (CNV) in normal stress response, aging and pathology, with a focus on 1q12 loci. We postulate a close link between transcription of SatII/III repeats and their CNV. The accrued body of data suggests a hypothetical universal mechanism, which provides for SatIII copy gain during the stress response, alongside with another, more hypothetical reverse mechanism that might reduce the mean SatIII copy number, likely via the selection of cells with excessively large 1q12 loci. Both mechanisms, working alternatively like swings of the pendulum, may ensure the balance of SatIII copy numbers and optimum stress resistance. This model is verified on the most recent data on SatIII CNV in pathology and therapy, aging, senescence and response to genotoxic stress in vitro.
Collapse
|
22
|
Amiad-Pavlov D, Lorber D, Bajpai G, Reuveny A, Roncato F, Alon R, Safran S, Volk T. Live imaging of chromatin distribution reveals novel principles of nuclear architecture and chromatin compartmentalization. SCIENCE ADVANCES 2021; 7:7/23/eabf6251. [PMID: 34078602 PMCID: PMC8172175 DOI: 10.1126/sciadv.abf6251] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 04/15/2021] [Indexed: 05/12/2023]
Abstract
Live imaging of chromatin in an intact organism reveals a novel mode of mesoscale chromatin organization at nuclear periphery.
Collapse
Affiliation(s)
- Daria Amiad-Pavlov
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Dana Lorber
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Gaurav Bajpai
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Adriana Reuveny
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Francesco Roncato
- Department of Immunology Weizmann Institute of Science, Rehovot, Israel
| | - Ronen Alon
- Department of Immunology Weizmann Institute of Science, Rehovot, Israel
| | - Samuel Safran
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Talila Volk
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| |
Collapse
|
23
|
Sajid A, Lalani EN, Chen B, Hashimoto T, Griffin DK, Bhartiya A, Thompson G, Robinson IK, Yusuf M. Ultra-Structural Imaging Provides 3D Organization of 46 Chromosomes of a Human Lymphocyte Prophase Nucleus. Int J Mol Sci 2021; 22:ijms22115987. [PMID: 34206020 PMCID: PMC8198510 DOI: 10.3390/ijms22115987] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 05/21/2021] [Accepted: 05/23/2021] [Indexed: 11/18/2022] Open
Abstract
Three dimensional (3D) ultra-structural imaging is an important tool for unraveling the organizational structure of individual chromosomes at various stages of the cell cycle. Performing hitherto uninvestigated ultra-structural analysis of the human genome at prophase, we used serial block-face scanning electron microscopy (SBFSEM) to understand chromosomal architectural organization within 3D nuclear space. Acquired images allowed us to segment, reconstruct, and extract quantitative 3D structural information about the prophase nucleus and the preserved, intact individual chromosomes within it. Our data demonstrate that each chromosome can be identified with its homolog and classified into respective cytogenetic groups. Thereby, we present the first 3D karyotype built from the compact axial structure seen on the core of all prophase chromosomes. The chromosomes display parallel-aligned sister chromatids with familiar chromosome morphologies with no crossovers. Furthermore, the spatial positions of all 46 chromosomes revealed a pattern showing a gene density-based correlation and a neighborhood map of individual chromosomes based on their relative spatial positioning. A comprehensive picture of 3D chromosomal organization at the nanometer level in a single human lymphocyte cell is presented.
Collapse
Affiliation(s)
- Atiqa Sajid
- Centre for Regenerative Medicine and Stem Cell Research, Aga Khan University, Karachi 74800, Pakistan; (A.S.); (E.-N.L.)
| | - El-Nasir Lalani
- Centre for Regenerative Medicine and Stem Cell Research, Aga Khan University, Karachi 74800, Pakistan; (A.S.); (E.-N.L.)
| | - Bo Chen
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK; (B.C.); (A.B.); (I.K.R.)
- School of Materials Science and Engineering, Tongji University, Shanghai 201804, China
- Key Laboratory of Performance Evolution and Control for Engineering Structures of the Ministry of Education, Tongji University, Shanghai 200092, China
| | - Teruo Hashimoto
- Department of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, UK; (T.H.); (G.T.)
| | | | - Archana Bhartiya
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK; (B.C.); (A.B.); (I.K.R.)
| | - George Thompson
- Department of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, UK; (T.H.); (G.T.)
| | - Ian K. Robinson
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK; (B.C.); (A.B.); (I.K.R.)
- Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Mohammed Yusuf
- Centre for Regenerative Medicine and Stem Cell Research, Aga Khan University, Karachi 74800, Pakistan; (A.S.); (E.-N.L.)
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK; (B.C.); (A.B.); (I.K.R.)
- Correspondence:
| |
Collapse
|
24
|
Aboelnour E, Bonev B. Decoding the organization, dynamics, and function of the 4D genome. Dev Cell 2021; 56:1562-1573. [PMID: 33984271 DOI: 10.1016/j.devcel.2021.04.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/15/2021] [Accepted: 04/21/2021] [Indexed: 11/15/2022]
Abstract
Understanding how complex cell-fate decisions emerge at the molecular level is a key challenge in developmental biology. Despite remarkable progress in decoding the contribution of the linear epigenome, how spatial genome architecture functionally informs changes in gene expression remains unclear. In this review, we discuss recent insights in elucidating the molecular landscape of genome folding, emphasizing the multilayered nature of the 3D genome, its importance for gene regulation, and its spatiotemporal dynamics. Finally, we discuss how these new concepts and emergent technologies will enable us to address some of the outstanding questions in development and disease.
Collapse
Affiliation(s)
- Erin Aboelnour
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Boyan Bonev
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Biomedical Center (BMC), Faculty of Medicine, LMU Munich, Germany.
| |
Collapse
|
25
|
Falk M, Hausmann M. A Paradigm Revolution or Just Better Resolution-Will Newly Emerging Superresolution Techniques Identify Chromatin Architecture as a Key Factor in Radiation-Induced DNA Damage and Repair Regulation? Cancers (Basel) 2020; 13:E18. [PMID: 33374540 PMCID: PMC7793109 DOI: 10.3390/cancers13010018] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 12/18/2020] [Indexed: 02/07/2023] Open
Abstract
DNA double-strand breaks (DSBs) have been recognized as the most serious lesions in irradiated cells. While several biochemical pathways capable of repairing these lesions have been identified, the mechanisms by which cells select a specific pathway for activation at a given DSB site remain poorly understood. Our knowledge of DSB induction and repair has increased dramatically since the discovery of ionizing radiation-induced foci (IRIFs), initiating the possibility of spatiotemporally monitoring the assembly and disassembly of repair complexes in single cells. IRIF exploration revealed that all post-irradiation processes-DSB formation, repair and misrepair-are strongly dependent on the characteristics of DSB damage and the microarchitecture of the whole affected chromatin domain in addition to the cell status. The microscale features of IRIFs, such as their morphology, mobility, spatiotemporal distribution, and persistence kinetics, have been linked to repair mechanisms. However, the influence of various biochemical and structural factors and their specific combinations on IRIF architecture remains unknown, as does the hierarchy of these factors in the decision-making process for a particular repair mechanism at each individual DSB site. New insights into the relationship between the physical properties of the incident radiation, chromatin architecture, IRIF architecture, and DSB repair mechanisms and repair efficiency are expected from recent developments in optical superresolution microscopy (nanoscopy) techniques that have shifted our ability to analyze chromatin and IRIF architectures towards the nanoscale. In the present review, we discuss this relationship, attempt to correlate still rather isolated nanoscale studies with already better-understood aspects of DSB repair at the microscale, and consider whether newly emerging "correlated multiscale structuromics" can revolutionarily enhance our knowledge in this field.
Collapse
Affiliation(s)
- Martin Falk
- Institute of Biophysics, The Czech Academy of Sciences, 612 65 Brno, Czech Republic
| | - Michael Hausmann
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany;
| |
Collapse
|
26
|
Korsholm LM, Gál Z, Nieto B, Quevedo O, Boukoura S, Lund CC, Larsen DH. Recent advances in the nucleolar responses to DNA double-strand breaks. Nucleic Acids Res 2020; 48:9449-9461. [PMID: 32857853 PMCID: PMC7515731 DOI: 10.1093/nar/gkaa713] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/13/2020] [Accepted: 08/26/2020] [Indexed: 12/15/2022] Open
Abstract
DNA damage poses a serious threat to human health and cells therefore continuously monitor and repair DNA lesions across the genome. Ribosomal DNA is a genomic domain that represents a particular challenge due to repetitive sequences, high transcriptional activity and its localization in the nucleolus, where the accessibility of DNA repair factors is limited. Recent discoveries have significantly extended our understanding of how cells respond to DNA double-strand breaks (DSBs) in the nucleolus, and new kinases and multiple down-stream targets have been identified. Restructuring of the nucleolus can occur as a consequence of DSBs and new data point to an active regulation of this process, challenging previous views. Furthermore, new insights into coordination of cell cycle phases and ribosomal DNA repair argue against existing concepts. In addition, the importance of nucleolar-DNA damage response (n-DDR) mechanisms for maintenance of genome stability and the potential of such factors as anti-cancer targets is becoming apparent. This review will provide a detailed discussion of recent findings and their implications for our understanding of the n-DDR. The n-DDR shares features with the DNA damage response (DDR) elsewhere in the genome but is also emerging as an independent response unique to ribosomal DNA and the nucleolus.
Collapse
Affiliation(s)
| | | | - Blanca Nieto
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Oliver Quevedo
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Stavroula Boukoura
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Casper Carstens Lund
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | | |
Collapse
|
27
|
Misteli T. The Self-Organizing Genome: Principles of Genome Architecture and Function. Cell 2020; 183:28-45. [PMID: 32976797 PMCID: PMC7541718 DOI: 10.1016/j.cell.2020.09.014] [Citation(s) in RCA: 287] [Impact Index Per Article: 71.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 08/03/2020] [Accepted: 09/02/2020] [Indexed: 01/17/2023]
Abstract
Genomes have complex three-dimensional architectures. The recent convergence of genetic, biochemical, biophysical, and cell biological methods has uncovered several fundamental principles of genome organization. They highlight that genome function is a major driver of genome architecture and that structural features of chromatin act as modulators, rather than binary determinants, of genome activity. The interplay of these principles in the context of self-organization can account for the emergence of structural chromatin features, the diversity and single-cell heterogeneity of nuclear architecture in cell types and tissues, and explains evolutionarily conserved functional features of genomes, including plasticity and robustness.
Collapse
Affiliation(s)
- Tom Misteli
- National Cancer Institute, NIH, Bethesda, MD 20892, USA.
| |
Collapse
|