1
|
Singh G, Skibbens RV. Fdo1, Fkh1, Fkh2, and the Swi6-Mbp1 MBF complex regulate Mcd1 levels to impact eco1 rad61 cell growth in Saccharomyces cerevisiae. Genetics 2024; 228:iyae128. [PMID: 39110836 PMCID: PMC11457938 DOI: 10.1093/genetics/iyae128] [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: 06/10/2024] [Accepted: 07/19/2024] [Indexed: 10/09/2024] Open
Abstract
Cohesins promote proper chromosome segregation, gene transcription, genomic architecture, DNA condensation, and DNA damage repair. Mutations in either cohesin subunits or regulatory genes can give rise to severe developmental abnormalities (such as Robert Syndrome and Cornelia de Lange Syndrome) and also are highly correlated with cancer. Despite this, little is known about cohesin regulation. Eco1 (ESCO2/EFO2 in humans) and Rad61 (WAPL in humans) represent two such regulators but perform opposing roles. Eco1 acetylation of cohesin during S phase, for instance, stabilizes cohesin-DNA binding to promote sister chromatid cohesion. On the other hand, Rad61 promotes the dissociation of cohesin from DNA. While Eco1 is essential, ECO1 and RAD61 co-deletion results in yeast cell viability, but only within a limited temperature range. Here, we report that eco1rad61 cell lethality is due to reduced levels of the cohesin subunit Mcd1. Results from a suppressor screen further reveals that FDO1 deletion rescues the temperature-sensitive (ts) growth defects exhibited by eco1rad61 double mutant cells by increasing Mcd1 levels. Regulation of MCD1 expression, however, appears more complex. Elevated expression of MBP1, which encodes a subunit of the MBF transcription complex, also rescues eco1rad61 cell growth defects. Elevated expression of SWI6, however, which encodes the Mbp1-binding partner of MBF, exacerbates eco1rad61 cell growth and also abrogates the Mpb1-dependent rescue. Finally, we identify two additional transcription factors, Fkh1 and Fkh2, that impact MCD1 expression. In combination, these findings provide new insights into the nuanced and multi-faceted transcriptional pathways that impact MCD1 expression.
Collapse
Affiliation(s)
- Gurvir Singh
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
| | - Robert V Skibbens
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
| |
Collapse
|
2
|
Chang LH, Noordermeer D. Permeable TAD boundaries and their impact on genome-associated functions. Bioessays 2024; 46:e2400137. [PMID: 39093600 DOI: 10.1002/bies.202400137] [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: 06/05/2024] [Revised: 07/12/2024] [Accepted: 07/17/2024] [Indexed: 08/04/2024]
Abstract
TAD boundaries are genomic elements that separate biological processes in neighboring domains by blocking DNA loops that are formed through Cohesin-mediated loop extrusion. Most TAD boundaries consist of arrays of binding sites for the CTCF protein, whose interaction with the Cohesin complex blocks loop extrusion. TAD boundaries are not fully impermeable though and allow a limited amount of inter-TAD loop formation. Based on the reanalysis of Nano-C data, a multicontact Chromosome Conformation Capture assay, we propose a model whereby clustered CTCF binding sites promote the successive stalling of Cohesin and subsequent dissociation from the chromatin. A fraction of Cohesin nonetheless achieves boundary read-through. Due to a constant rate of Cohesin dissociation elsewhere in the genome, the maximum length of inter-TAD loops is restricted though. We speculate that the DNA-encoded organization of stalling sites regulates TAD boundary permeability and discuss implications for enhancer-promoter loop formation and other genomic processes.
Collapse
Affiliation(s)
- Li-Hsin Chang
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Blood and Transplant Research Unit in Precision Cellular Therapeutics, National Institute of Health Research, Oxford, UK
| | - Daan Noordermeer
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette, France
| |
Collapse
|
3
|
Ortabozkoyun H, Huang PY, Gonzalez-Buendia E, Cho H, Kim SY, Tsirigos A, Mazzoni EO, Reinberg D. Members of an array of zinc-finger proteins specify distinct Hox chromatin boundaries. Mol Cell 2024; 84:3406-3422.e6. [PMID: 39173638 DOI: 10.1016/j.molcel.2024.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 05/06/2024] [Accepted: 08/05/2024] [Indexed: 08/24/2024]
Abstract
Partitioning of repressive from actively transcribed chromatin in mammalian cells fosters cell-type-specific gene expression patterns. While this partitioning is reconstructed during differentiation, the chromatin occupancy of the key insulator, CCCTC-binding factor (CTCF), is unchanged at the developmentally important Hox clusters. Thus, dynamic changes in chromatin boundaries must entail other activities. Given its requirement for chromatin loop formation, we examined cohesin-based chromatin occupancy without known insulators, CTCF and Myc-associated zinc-finger protein (MAZ), and identified a family of zinc-finger proteins (ZNFs), some of which exhibit tissue-specific expression. Two such ZNFs foster chromatin boundaries at the Hox clusters that are distinct from each other and from MAZ. PATZ1 was critical to the thoracolumbar boundary in differentiating motor neurons and mouse skeleton, while ZNF263 contributed to cervicothoracic boundaries. We propose that these insulating activities act with cohesin, alone or combinatorially, with or without CTCF, to implement precise positional identity and cell fate during development.
Collapse
Affiliation(s)
- Havva Ortabozkoyun
- Howard Hughes Medical Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA.
| | - Pin-Yao Huang
- Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA
| | - Edgar Gonzalez-Buendia
- Howard Hughes Medical Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA
| | - Hyein Cho
- Department of Pathology, NYU Langone Health, New York, NY 10016, USA; Applied Bioinformatics Laboratories, NYU Langone Health, New York, NY 10016, USA; Department of Medicine, Division of Precision Medicine, NYU Langone Health, New York, NY 10016, USA
| | - Sang Y Kim
- Department of Pathology, NYU Langone Health, New York, NY 10016, USA
| | - Aristotelis Tsirigos
- Department of Pathology, NYU Langone Health, New York, NY 10016, USA; Applied Bioinformatics Laboratories, NYU Langone Health, New York, NY 10016, USA; Institute for Computational Medicine, NYU Langone Health, New York, NY 10016, USA
| | - Esteban O Mazzoni
- Department of Cell Biology, NYU Langone Health, New York, NY 10016, USA
| | - Danny Reinberg
- Howard Hughes Medical Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA.
| |
Collapse
|
4
|
Schooley A, Venev SV, Aksenova V, Navarrete E, Dasso M, Dekker J. Interphase chromosome conformation is specified by distinct folding programs inherited via mitotic chromosomes or through the cytoplasm. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.16.613305. [PMID: 39345587 PMCID: PMC11429855 DOI: 10.1101/2024.09.16.613305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
Identity-specific interphase chromosome conformation must be re-established each time a cell divides. To understand how interphase folding is inherited, we developed an experimental approach that physically segregates mediators of G1 folding that are intrinsic to mitotic chromosomes from cytoplasmic factors. Proteins essential for nuclear transport, RanGAP1 and Nup93, were degraded in pro-metaphase arrested DLD-1 cells to prevent the establishment of nucleo-cytoplasmic transport during mitotic exit and isolate the decondensing mitotic chromatin of G1 daughter cells from the cytoplasm. Using this approach, we discover a transient folding intermediate entirely driven by chromosome-intrinsic factors. In addition to conventional compartmental segregation, this chromosome-intrinsic folding program leads to prominent genome-scale microcompartmentalization of mitotically bookmarked and cell type-specific cis-regulatory elements. This microcompartment conformation is formed during telophase and subsequently modulated by a second folding program driven by factors inherited through the cytoplasm in G1. This nuclear import-dependent folding program includes cohesin and factors involved in transcription and RNA processing. The combined and inter-dependent action of chromosome-intrinsic and cytoplasmic inherited folding programs determines the interphase chromatin conformation as cells exit mitosis.
Collapse
Affiliation(s)
- Allana Schooley
- Department of Systems Biology, University of Massachusetts Chan Medical School; Worcester, USA
| | - Sergey V. Venev
- Department of Systems Biology, University of Massachusetts Chan Medical School; Worcester, USA
| | - Vasilisa Aksenova
- Division of Molecular and Cellular Biology, National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4480, USA
| | - Emily Navarrete
- Institute for Medical Engineering and Science and Department of Physics, Massachusetts Institute of Technology; Cambridge, USA
| | - Mary Dasso
- Division of Molecular and Cellular Biology, National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4480, USA
| | - Job Dekker
- Department of Systems Biology, University of Massachusetts Chan Medical School; Worcester, USA
- Howard Hughes Medical Institute; Chevy Chase, USA
| |
Collapse
|
5
|
Ortabozkoyun H, Huang PY, Gonzalez-Buendia E, Cho H, Kim SY, Tsirigos A, Mazzoni EO, Reinberg D. Members of an array of zinc finger proteins specify distinct Hox chromatin boundaries. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.25.538167. [PMID: 37162865 PMCID: PMC10168243 DOI: 10.1101/2023.04.25.538167] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Partitioning of repressive from actively transcribed chromatin in mammalian cells fosters cell-type specific gene expression patterns. While this partitioning is reconstructed during differentiation, the chromatin occupancy of the key insulator, CTCF, is unchanged at the developmentally important Hox clusters. Thus, dynamic changes in chromatin boundaries must entail other activities. Given its requirement for chromatin loop formation, we examined cohesin-based chromatin occupancy without known insulators, CTCF and MAZ, and identified a family of zinc finger proteins (ZNFs), some of which exhibit tissue-specific expression. Two such ZNFs foster chromatin boundaries at the Hox clusters that are distinct from each other and from MAZ. PATZ1 was critical to the thoracolumbar boundary in differentiating motor neurons and mouse skeleton, while ZNF263 contributed to cervicothoracic boundaries. We propose that these insulating activities act with cohesin, alone or combinatorially, with or without CTCF, to implement precise positional identity and cell fate during development.
Collapse
|
6
|
Salari H, Fourel G, Jost D. Transcription regulates the spatio-temporal dynamics of genes through micro-compartmentalization. Nat Commun 2024; 15:5393. [PMID: 38918438 PMCID: PMC11199603 DOI: 10.1038/s41467-024-49727-7] [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: 07/24/2023] [Accepted: 06/17/2024] [Indexed: 06/27/2024] Open
Abstract
Although our understanding of the involvement of heterochromatin architectural factors in shaping nuclear organization is improving, there is still ongoing debate regarding the role of active genes in this process. In this study, we utilize publicly-available Micro-C data from mouse embryonic stem cells to investigate the relationship between gene transcription and 3D gene folding. Our analysis uncovers a nonmonotonic - globally positive - correlation between intragenic contact density and Pol II occupancy, independent of cohesin-based loop extrusion. Through the development of a biophysical model integrating the role of transcription dynamics within a polymer model of chromosome organization, we demonstrate that Pol II-mediated attractive interactions with limited valency between transcribed regions yield quantitative predictions consistent with chromosome-conformation-capture and live-imaging experiments. Our work provides compelling evidence that transcriptional activity shapes the 4D genome through Pol II-mediated micro-compartmentalization.
Collapse
Affiliation(s)
- Hossein Salari
- Laboratoire de Biologie et Modélisation de la Cellule, École Normale Supérieure de Lyon, CNRS, UMR5239, Inserm U1293, Université Claude Bernard Lyon 1, 46 Allée d'Italie, 69007, Lyon, France.
- École Normale Supérieure de Lyon, CNRS, Laboratoire de Physique, 46 Allée d'Italie, 69007, Lyon, France.
| | - Geneviève Fourel
- Laboratoire de Biologie et Modélisation de la Cellule, École Normale Supérieure de Lyon, CNRS, UMR5239, Inserm U1293, Université Claude Bernard Lyon 1, 46 Allée d'Italie, 69007, Lyon, France
| | - Daniel Jost
- Laboratoire de Biologie et Modélisation de la Cellule, École Normale Supérieure de Lyon, CNRS, UMR5239, Inserm U1293, Université Claude Bernard Lyon 1, 46 Allée d'Italie, 69007, Lyon, France.
| |
Collapse
|
7
|
Magnitov M, de Wit E. Attraction and disruption: how loop extrusion and compartmentalisation shape the nuclear genome. Curr Opin Genet Dev 2024; 86:102194. [PMID: 38636335 PMCID: PMC11190842 DOI: 10.1016/j.gde.2024.102194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 03/21/2024] [Accepted: 03/31/2024] [Indexed: 04/20/2024]
Abstract
Chromatin loops, which bring two distal loci of the same chromosome into close physical proximity, are the ubiquitous units of the three-dimensional genome. Recent advances in understanding the spatial organisation of chromatin suggest that several distinct mechanisms control chromatin interactions, such as loop extrusion by cohesin complexes, compartmentalisation by phase separation, direct protein-protein interactions and others. Here, we review different types of chromatin loops and highlight the factors and processes involved in their regulation. We discuss how loop extrusion and compartmentalisation shape chromatin interactions and how these two processes can either positively or negatively influence each other.
Collapse
Affiliation(s)
- Mikhail Magnitov
- Division of Gene Regulation, the Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands. https://twitter.com/@MMagnitov
| | - Elzo de Wit
- Division of Gene Regulation, the Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands.
| |
Collapse
|
8
|
Samejima K, Gibcus JH, Abraham S, Cisneros-Soberanis F, Samejima I, Beckett AJ, Pučeková N, Abad MA, Medina-Pritchard B, Paulson JR, Xie L, Jeyaprakash AA, Prior IA, Mirny LA, Dekker J, Goloborodko A, Earnshaw WC. Rules of engagement for condensins and cohesins guide mitotic chromosome formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.18.590027. [PMID: 38659940 PMCID: PMC11042376 DOI: 10.1101/2024.04.18.590027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
During mitosis, interphase chromatin is rapidly converted into rod-shaped mitotic chromosomes. Using Hi-C, imaging, proteomics and polymer modeling, we determine how the activity and interplay between loop-extruding SMC motors accomplishes this dramatic transition. Our work reveals rules of engagement for SMC complexes that are critical for allowing cells to refold interphase chromatin into mitotic chromosomes. We find that condensin disassembles interphase chromatin loop organization by evicting or displacing extrusive cohesin. In contrast, condensin bypasses cohesive cohesins, thereby maintaining sister chromatid cohesion while separating the sisters. Studies of mitotic chromosomes formed by cohesin, condensin II and condensin I alone or in combination allow us to develop new models of mitotic chromosome conformation. In these models, loops are consecutive and not overlapping, implying that condensins do not freely pass one another but stall upon encountering each other. The dynamics of Hi-C interactions and chromosome morphology reveal that during prophase loops are extruded in vivo at ~1-3 kb/sec by condensins as they form a disordered discontinuous helical scaffold within individual chromatids.
Collapse
Affiliation(s)
- Kumiko Samejima
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| | - Johan H. Gibcus
- Department of Systems Biology, University of Massachusetts Chan Medical School; Worcester, USA
| | - Sameer Abraham
- Institute for Medical Engineering and Science and Department of Physics, Massachusetts Institute of Technology; Cambridge, USA
| | | | - Itaru Samejima
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| | - Alison J. Beckett
- Department of Molecular and Clinical Cancer Medicine, University of Liverpool; Liverpool, UK
| | - Nina Pučeková
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| | - Maria Alba Abad
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| | - Bethan Medina-Pritchard
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| | - James R. Paulson
- Department of Chemistry, University of Wisconsin-Oshkosh; Oshkosh, USA
| | - Linfeng Xie
- Department of Chemistry, University of Wisconsin-Oshkosh; Oshkosh, USA
| | - A. Arockia Jeyaprakash
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
- Gene Center Munich, Ludwig-Maximilians-Universität München; Munich, Germany
| | - Ian A. Prior
- Department of Molecular and Clinical Cancer Medicine, University of Liverpool; Liverpool, UK
| | - Leonid A. Mirny
- Institute for Medical Engineering and Science and Department of Physics, Massachusetts Institute of Technology; Cambridge, USA
| | - Job Dekker
- Department of Systems Biology, University of Massachusetts Chan Medical School; Worcester, USA
- Howard Hughes Medical Institute; Chevy Chase, USA
| | | | - William C. Earnshaw
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| |
Collapse
|
9
|
Golov AK, Gavrilov AA. Cohesin-Dependent Loop Extrusion: Molecular Mechanics and Role in Cell Physiology. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:601-625. [PMID: 38831499 DOI: 10.1134/s0006297924040023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 12/29/2023] [Accepted: 02/15/2024] [Indexed: 06/05/2024]
Abstract
The most prominent representatives of multisubunit SMC complexes, cohesin and condensin, are best known as structural components of mitotic chromosomes. It turned out that these complexes, as well as their bacterial homologues, are molecular motors, the ATP-dependent movement of these complexes along DNA threads leads to the formation of DNA loops. In recent years, we have witnessed an avalanche-like accumulation of data on the process of SMC dependent DNA looping, also known as loop extrusion. This review briefly summarizes the current understanding of the place and role of cohesin-dependent extrusion in cell physiology and presents a number of models describing the potential molecular mechanism of extrusion in a most compelling way. We conclude the review with a discussion of how the capacity of cohesin to extrude DNA loops may be mechanistically linked to its involvement in sister chromatid cohesion.
Collapse
Affiliation(s)
- Arkadiy K Golov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
- Technion - Israel Institute of Technology, Haifa, 3525433, Israel
| | - Alexey A Gavrilov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
| |
Collapse
|
10
|
Rittenhouse NL, Dowen JM. Cohesin regulation and roles in chromosome structure and function. Curr Opin Genet Dev 2024; 85:102159. [PMID: 38382406 PMCID: PMC10947815 DOI: 10.1016/j.gde.2024.102159] [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: 09/12/2023] [Revised: 01/22/2024] [Accepted: 01/27/2024] [Indexed: 02/23/2024]
Abstract
Chromosome structure regulates DNA-templated processes such as transcription of genes. Dynamic changes to chromosome structure occur during development and in disease contexts. The cohesin complex is a molecular motor that regulates chromosome structure by generating DNA loops that bring two distal genomic sites into close spatial proximity. There are many open questions regarding the formation and dissolution of DNA loops, as well as the role(s) of DNA loops in regulating transcription of the interphase genome. This review focuses on recent discoveries that provide molecular insights into the role of cohesin and chromosome structure in gene transcription during development and disease.
Collapse
Affiliation(s)
- Natalie L Rittenhouse
- Curriculum in Genetics & Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jill M Dowen
- Department of Biophysics & Biochemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| |
Collapse
|
11
|
Miglierina E, Ordanoska D, Le Noir S, Laffleur B. RNA processing mechanisms contribute to genome organization and stability in B cells. Oncogene 2024; 43:615-623. [PMID: 38287115 PMCID: PMC10890934 DOI: 10.1038/s41388-024-02952-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 01/31/2024]
Abstract
RNA processing includes post-transcriptional mechanisms controlling RNA quality and quantity to ensure cellular homeostasis. Noncoding (nc) RNAs that are regulated by these dynamic processes may themselves fulfill effector and/or regulatory functions, and recent studies demonstrated the critical role of RNAs in organizing both chromatin and genome architectures. Furthermore, RNAs can threaten genome integrity when accumulating as DNA:RNA hybrids, but could also facilitate DNA repair depending on the molecular context. Therefore, by qualitatively and quantitatively fine-tuning RNAs, RNA processing contributes directly or indirectly to chromatin states, genome organization, and genome stability. B lymphocytes represent a unique model to study these interconnected mechanisms as they express ncRNAs transcribed from key specific sequences before undergoing physiological genetic remodeling processes, including V(D)J recombination, somatic hypermutation, and class switch recombination. RNA processing actors ensure the regulation and degradation of these ncRNAs for efficient DNA repair and immunoglobulin gene remodeling while failure leads to B cell development alterations, aberrant DNA repair, and pathological translocations. This review highlights how RNA processing mechanisms contribute to genome architecture and stability, with emphasis on their critical roles during B cell development, enabling physiological DNA remodeling while preventing lymphomagenesis.
Collapse
Affiliation(s)
- Emma Miglierina
- University of Rennes, Inserm, EFS Bretagne, CHU Rennes, UMR, 1236, Rennes, France
| | - Delfina Ordanoska
- University of Rennes, Inserm, EFS Bretagne, CHU Rennes, UMR, 1236, Rennes, France
| | - Sandrine Le Noir
- UMR CNRS 7276, Inserm 1262, Université de Limoges: Contrôle de la Réponse Immune B et des Lymphoproliférations, Team 2, B-NATION: B cell Nuclear Architecture, Immunoglobulin genes and Oncogenes, Limoges, France
| | - Brice Laffleur
- University of Rennes, Inserm, EFS Bretagne, CHU Rennes, UMR, 1236, Rennes, France.
| |
Collapse
|
12
|
Terrón-Bautista J, Martínez-Sánchez MDM, López-Hernández L, Vadusevan AA, García-Domínguez M, Williams RS, Aguilera A, Millán-Zambrano G, Cortés-Ledesma F. Topological regulation of the estrogen transcriptional response by ZATT-mediated inhibition of TOP2B activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.576640. [PMID: 38328138 PMCID: PMC10849543 DOI: 10.1101/2024.01.22.576640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Human type-II topoisomerases, TOP2A and TOP2B, remove transcription associated DNA supercoiling, thereby affecting gene-expression programs, and have recently been associated with 3D genome architecture. Here, we study the regulatory roles of TOP2 paralogs in response to estrogen, which triggers an acute transcriptional induction that involves rewiring of genome organization. We find that, whereas TOP2A facilitates transcription, as expected for a topoisomerase, TOP2B limits the estrogen response. Consistent with this, TOP2B activity is locally downregulated upon estrogen treatment to favor the establishment and stabilization of regulatory chromatin contacts, likely through an accumulation of DNA supercoiling. We show that estrogen-mediated inhibition of TOP2B requires estrogen receptor α (ERα), a non-catalytic function of TOP2A, and the action of the atypical SUMO-ligase ZATT. This mechanism of topological transcriptional-control, which may be shared by additional gene-expression circuits, highlights the relevance of DNA topoisomerases as central actors of genome dynamics.
Collapse
Affiliation(s)
- José Terrón-Bautista
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
- Topology and DNA Breaks Group, Spanish National Cancer Centre (CNIO), Madrid 28029, Spain
| | | | - Laura López-Hernández
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
- Departamento de Genética, Universidad de Sevilla, Spain
| | - Ananda Ayyappan Vadusevan
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, US Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Mario García-Domínguez
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
| | - R. Scott Williams
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, US Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
- Departamento de Genética, Universidad de Sevilla, Spain
| | - Gonzalo Millán-Zambrano
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
- Departamento de Genética, Universidad de Sevilla, Spain
| | - Felipe Cortés-Ledesma
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
- Topology and DNA Breaks Group, Spanish National Cancer Centre (CNIO), Madrid 28029, Spain
- Lead contact
| |
Collapse
|
13
|
Calvo-Roitberg E, Carroll CL, Venev SV, Kim G, Mick ST, Dekker J, Fiszbein A, Pai AA. mRNA initiation and termination are spatially coordinated. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.05.574404. [PMID: 38260419 PMCID: PMC10802295 DOI: 10.1101/2024.01.05.574404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The expression of a precise mRNA transcriptome is crucial for establishing cell identity and function, with dozens of alternative isoforms produced for a single gene sequence. The regulation of mRNA isoform usage occurs by the coordination of co-transcriptional mRNA processing mechanisms across a gene. Decisions involved in mRNA initiation and termination underlie the largest extent of mRNA isoform diversity, but little is known about any relationships between decisions at both ends of mRNA molecules. Here, we systematically profile the joint usage of mRNA transcription start sites (TSSs) and polyadenylation sites (PASs) across tissues and species. Using both short and long read RNA-seq data, we observe that mRNAs preferentially using upstream TSSs also tend to use upstream PASs, and congruently, the usage of downstream sites is similarly paired. This observation suggests that mRNA 5' end choice may directly influence mRNA 3' ends. Our results suggest a novel "Positional Initiation-Termination Axis" (PITA), in which the usage of alternative terminal sites are coupled based on the order in which they appear in the genome. PITA isoforms are more likely to encode alternative protein domains and use conserved sites. PITA is strongly associated with the length of genomic features, such that PITA is enriched in longer genes with more area devoted to regions that regulate alternative 5' or 3' ends. Strikingly, we found that PITA genes are more likely than non-PITA genes to have multiple, overlapping chromatin structural domains related to pairing of ordinally coupled start and end sites. In turn, PITA coupling is also associated with fast RNA Polymerase II (RNAPII) trafficking across these long gene regions. Our findings indicate that a combination of spatial and kinetic mechanisms couple transcription initiation and mRNA 3' end decisions based on ordinal position to define the expression mRNA isoforms.
Collapse
Affiliation(s)
| | | | - Sergey V. Venev
- Department of Systems Biology, University Massachusetts Chan Medical School, Worcester, MA
| | - GyeungYun Kim
- Department of Biology, Boston University, Boston, MA
| | | | - Job Dekker
- Department of Systems Biology, University Massachusetts Chan Medical School, Worcester, MA
- Howard Hughes Medical Institute, Chevy Chase, MD
| | - Ana Fiszbein
- Department of Biology, Boston University, Boston, MA
- Center for Computing & Data Sciences, Boston University, Boston, MA
| | - Athma A. Pai
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA
| |
Collapse
|
14
|
Allou L, Mundlos S. Disruption of regulatory domains and novel transcripts as disease-causing mechanisms. Bioessays 2023; 45:e2300010. [PMID: 37381881 DOI: 10.1002/bies.202300010] [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: 01/16/2023] [Revised: 05/24/2023] [Accepted: 06/06/2023] [Indexed: 06/30/2023]
Abstract
Deletions, duplications, insertions, inversions, and translocations, collectively called structural variations (SVs), affect more base pairs of the genome than any other sequence variant. The recent technological advancements in genome sequencing have enabled the discovery of tens of thousands of SVs per human genome. These SVs primarily affect non-coding DNA sequences, but the difficulties in interpreting their impact limit our understanding of human disease etiology. The functional annotation of non-coding DNA sequences and methodologies to characterize their three-dimensional (3D) organization in the nucleus have greatly expanded our understanding of the basic mechanisms underlying gene regulation, thereby improving the interpretation of SVs for their pathogenic impact. Here, we discuss the various mechanisms by which SVs can result in altered gene regulation and how these mechanisms can result in rare genetic disorders. Beyond changing gene expression, SVs can produce novel gene-intergenic fusion transcripts at the SV breakpoints.
Collapse
Affiliation(s)
- Lila Allou
- RG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Institute for Medical and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Stefan Mundlos
- RG Development & Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Institute for Medical and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Therapies, Charité-Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
15
|
Sexton T, Platania A, Erb C, Barbieri M, Molcrette B, Grandgirard E, de Kort M, Meabum K, Taylor T, Shchuka V, Kocanova S, Oliveira G, Mitchell J, Soutoglou E, Lenstra T, Molina N, Papantonis A, Bystricky K. Competition between transcription and loop extrusion modulates promoter and enhancer dynamics. RESEARCH SQUARE 2023:rs.3.rs-3164817. [PMID: 37645793 PMCID: PMC10462181 DOI: 10.21203/rs.3.rs-3164817/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
The spatiotemporal configuration of genes with distal regulatory elements, and the impact of chromatin mobility on transcription, remain unclear. Loop extrusion is an attractive model for bringing genetic elements together, but how this functionally interacts with transcription is also largely unknown. We combine live tracking of genomic loci and nascent transcripts with molecular dynamics simulations to assess the spatiotemporal arrangement of the Sox2 gene and its enhancer, in response to a battery of perturbations. We find a close link between chromatin mobility and transcriptional status: active elements display more constrained mobility, consistent with confinement within specialized nuclear sites, and alterations in enhancer mobility distinguish poised from transcribing alleles. Strikingly, we find that whereas loop extrusion and transcription factor-mediated clustering contribute to promoter-enhancer proximity, they have antagonistic effects on chromatin dynamics. This provides an experimental framework for the underappreciated role of chromatin dynamics in genome regulation.
Collapse
Affiliation(s)
- Tom Sexton
- IGBMC (Institute of Genetics and Molecular and Cellular Biology)
| | | | - Cathie Erb
- IGBMC (Institute of Genetics and Molecular and Cellular Biology)
| | | | | | | | | | | | | | | | | | | | | | | | | | - Nacho Molina
- IGBMC (Institute of Genetics and Molecular and Cellular Biology)
| | | | | |
Collapse
|
16
|
Corsi F, Rusch E, Goloborodko A. Loop extrusion rules: the next generation. Curr Opin Genet Dev 2023; 81:102061. [PMID: 37354885 DOI: 10.1016/j.gde.2023.102061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 05/12/2023] [Accepted: 05/18/2023] [Indexed: 06/26/2023]
Abstract
The interphase genome of vertebrates contains roughly 100 000 dynamic loops formed by cohesins. These loops are thought to play important roles in many functions, but their exact contribution in each case remains hotly disputed. The key challenge in studying these loops is the lack of a single experimental technique that could reliably and comprehensively visualize their locations and dynamics. Yet, we can infer them using theoretical models that integrate complementary experimental observations. Modeling proved instrumental in showing that cohesins form loops via extrusion. The loop extrusion model made numerous successful qualitative and quantitative predictions and inspired many experiments. However, it also demonstrated limited accuracy in predicting contact maps. Recent research suggests that the original model did not fully account for the intricate details of the mechanism of loop extrusion and its complex regulation. Here, we review the progress in visualizing extrusion and characterizing the cohesin cofactors. These discoveries can be summarized as 'rules' of cohesin movement along chromosomes and incorporated into the next generation of models. Such improved models will enable more accurate inferences of positions and dynamics of cohesin loops and generate better predictions for designing experiments.
Collapse
Affiliation(s)
- Flavia Corsi
- Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, 1030 Vienna, Austria. https://twitter.com/@flavia_corsi
| | - Emma Rusch
- Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, 1030 Vienna, Austria. https://twitter.com/@emma__rush
| | - Anton Goloborodko
- Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, 1030 Vienna, Austria.
| |
Collapse
|
17
|
Yin Z, Cui S, Xue S, Xie Y, Wang Y, Zhao C, Zhang Z, Wu T, Hou G, Wang W, Xie SQ, Wu Y, Guo Y. Identification of Two Subsets of Subcompartment A1 Associated with High Transcriptional Activity and Frequent Loop Extrusion. BIOLOGY 2023; 12:1058. [PMID: 37626945 PMCID: PMC10451812 DOI: 10.3390/biology12081058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 07/24/2023] [Accepted: 07/24/2023] [Indexed: 08/27/2023]
Abstract
Three-dimensional genome organization has been increasingly recognized as an important determinant of the precise regulation of gene expression in mammalian cells, yet the relationship between gene transcriptional activity and spatial subcompartment positioning is still not fully comprehended. Here, we first utilized genome-wide Hi-C data to infer eight types of subcompartment (labeled A1, A2, A3, A4, B1, B2, B3, and B4) in mouse embryonic stem cells and four primary differentiated cell types, including thymocytes, macrophages, neural progenitor cells, and cortical neurons. Transitions of subcompartments may confer gene expression changes in different cell types. Intriguingly, we identified two subsets of subcompartments defined by higher gene density and characterized by strongly looped contact domains, named common A1 and variable A1, respectively. We revealed that common A1, which includes highly expressed genes and abundant housekeeping genes, shows a ~2-fold higher gene density than the variable A1, where cell type-specific genes are significantly enriched. Thus, our study supports a model in which both types of genomic loci with constitutive and regulatory high transcriptional activity can drive the subcompartment A1 formation. Special chromatin subcompartment arrangement and intradomain interactions may, in turn, contribute to maintaining proper levels of gene expression, especially for regulatory non-housekeeping genes.
Collapse
Affiliation(s)
- Zihang Yin
- Sheng Yushou Center of Cell Biology and Immunology, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Z.Y.); (S.C.); (Y.X.); (Y.W.); (C.Z.); (Z.Z.); (T.W.)
- WLA Laboratories, Shanghai 201203, China
| | - Shuang Cui
- Sheng Yushou Center of Cell Biology and Immunology, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Z.Y.); (S.C.); (Y.X.); (Y.W.); (C.Z.); (Z.Z.); (T.W.)
- WLA Laboratories, Shanghai 201203, China
| | - Song Xue
- Department of Bioinformatics and Biostatistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China;
| | - Yufan Xie
- Sheng Yushou Center of Cell Biology and Immunology, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Z.Y.); (S.C.); (Y.X.); (Y.W.); (C.Z.); (Z.Z.); (T.W.)
- WLA Laboratories, Shanghai 201203, China
| | - Yefan Wang
- Sheng Yushou Center of Cell Biology and Immunology, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Z.Y.); (S.C.); (Y.X.); (Y.W.); (C.Z.); (Z.Z.); (T.W.)
- WLA Laboratories, Shanghai 201203, China
| | - Chengling Zhao
- Sheng Yushou Center of Cell Biology and Immunology, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Z.Y.); (S.C.); (Y.X.); (Y.W.); (C.Z.); (Z.Z.); (T.W.)
- WLA Laboratories, Shanghai 201203, China
| | - Zhiyu Zhang
- Sheng Yushou Center of Cell Biology and Immunology, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Z.Y.); (S.C.); (Y.X.); (Y.W.); (C.Z.); (Z.Z.); (T.W.)
- WLA Laboratories, Shanghai 201203, China
| | - Tao Wu
- Sheng Yushou Center of Cell Biology and Immunology, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Z.Y.); (S.C.); (Y.X.); (Y.W.); (C.Z.); (Z.Z.); (T.W.)
- WLA Laboratories, Shanghai 201203, China
| | - Guojun Hou
- Shanghai Institute of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai 200001, China;
| | - Wuming Wang
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China;
| | - Sheila Q. Xie
- MRC London Institute of Medical Sciences, London W12 0NN, UK;
- Institute of Clinical Sciences, Imperial College London, London W12 0NN, UK
| | - Yue Wu
- Department of Bioinformatics and Biostatistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China;
| | - Ya Guo
- Sheng Yushou Center of Cell Biology and Immunology, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Z.Y.); (S.C.); (Y.X.); (Y.W.); (C.Z.); (Z.Z.); (T.W.)
- WLA Laboratories, Shanghai 201203, China
| |
Collapse
|
18
|
Chiliński M, Lipiński J, Agarwal A, Ruan Y, Plewczynski D. Enhanced performance of gene expression predictive models with protein-mediated spatial chromatin interactions. Sci Rep 2023; 13:11693. [PMID: 37474564 PMCID: PMC10359366 DOI: 10.1038/s41598-023-38865-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 07/16/2023] [Indexed: 07/22/2023] Open
Abstract
There have been multiple attempts to predict the expression of the genes based on the sequence, epigenetics, and various other factors. To improve those predictions, we have decided to investigate adding protein-specific 3D interactions that play a significant role in the condensation of the chromatin structure in the cell nucleus. To achieve this, we have used the architecture of one of the state-of-the-art algorithms, ExPecto, and investigated the changes in the model metrics upon adding the spatially relevant data. We have used ChIA-PET interactions that are mediated by cohesin (24 cell lines), CTCF (4 cell lines), and RNAPOL2 (4 cell lines). As the output of the study, we have developed the Spatial Gene Expression (SpEx) algorithm that shows statistically significant improvements in most cell lines. We have compared ourselves to the baseline ExPecto model, which obtained a 0.82 Spearman's rank correlation coefficient (SCC) score, and 0.85, which is reported by newer Enformer were able to obtain the average correlation score of 0.83. However, in some cases (e.g. RNAPOL2 on GM12878), our improvement reached 0.04, and in some cases (e.g. RNAPOL2 on H1), we reached an SCC of 0.86.
Collapse
Affiliation(s)
- Mateusz Chiliński
- Laboratory of Bioinformatics and Computational Genomics, Faculty of Mathematics and Information Science, Warsaw University of Technology, 00-662, Warsaw, Poland
- Laboratory of Functional and Structural Genomics, Centre of New Technologies, University of Warsaw, 02-097, Warsaw, Poland
| | | | - Abhishek Agarwal
- Laboratory of Functional and Structural Genomics, Centre of New Technologies, University of Warsaw, 02-097, Warsaw, Poland
| | - Yijun Ruan
- The Jackson Laboratory for Genomic Medicine, 10 Discovery Drive, Farmington, CT, 06030, USA
- Life Sciences Institute, Zhejiang University, Zhejiang, Hangzhou, China
| | - Dariusz Plewczynski
- Laboratory of Bioinformatics and Computational Genomics, Faculty of Mathematics and Information Science, Warsaw University of Technology, 00-662, Warsaw, Poland.
- Laboratory of Functional and Structural Genomics, Centre of New Technologies, University of Warsaw, 02-097, Warsaw, Poland.
| |
Collapse
|
19
|
Ramasamy S, Aljahani A, Karpinska MA, Cao TBN, Velychko T, Cruz JN, Lidschreiber M, Oudelaar AM. The Mediator complex regulates enhancer-promoter interactions. Nat Struct Mol Biol 2023:10.1038/s41594-023-01027-2. [PMID: 37430065 DOI: 10.1038/s41594-023-01027-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 05/30/2023] [Indexed: 07/12/2023]
Abstract
Enhancer-mediated gene activation generally requires physical proximity between enhancers and their target gene promoters. However, the molecular mechanisms by which interactions between enhancers and promoters are formed are not well understood. Here, we investigate the function of the Mediator complex in the regulation of enhancer-promoter interactions, by combining rapid protein depletion and high-resolution MNase-based chromosome conformation capture approaches. We show that depletion of Mediator leads to reduced enhancer-promoter interaction frequencies, which are associated with a strong decrease in gene expression. In addition, we find increased interactions between CTCF-binding sites upon Mediator depletion. These changes in chromatin architecture are associated with a redistribution of the Cohesin complex on chromatin and a reduction in Cohesin occupancy at enhancers. Together, our results indicate that the Mediator and Cohesin complexes contribute to enhancer-promoter interactions and provide insights into the molecular mechanisms by which communication between enhancers and promoters is regulated.
Collapse
Affiliation(s)
- Shyam Ramasamy
- Genome Organization and Regulation, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Abrar Aljahani
- Genome Organization and Regulation, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Magdalena A Karpinska
- Genome Organization and Regulation, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - T B Ngoc Cao
- Genome Organization and Regulation, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Taras Velychko
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - J Neos Cruz
- Genome Organization and Regulation, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Michael Lidschreiber
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - A Marieke Oudelaar
- Genome Organization and Regulation, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
| |
Collapse
|
20
|
Zhang H, Blobel GA. Genome folding dynamics during the M-to-G1-phase transition. Curr Opin Genet Dev 2023; 80:102036. [PMID: 37099832 PMCID: PMC10280458 DOI: 10.1016/j.gde.2023.102036] [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: 01/05/2023] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 04/28/2023]
Abstract
All measurable features of higher-order chromosomal architecture undergo drastic reorganization as cells enter and exit mitosis. During mitosis, gene transcription is temporarily halted, the nuclear envelope is dismantled, and chromosomes undergo condensation. At this time, chromatin compartments, topologically associating domains (TADs), and loops that connect enhancers with promoters as well as CTCF/cohesin loops are dissolved. Upon G1 entry, genome organization is rebuilt in the daughter nuclei to resemble that of the mother nucleus. We survey recent studies that traced these features in relation to gene expression during the mitosis-to-G1-phase transition at high temporal resolution. Dissection of fluctuating architectural features informed the hierarchical relationships of chromosomal organization, the mechanisms by which they are formed, and their mutual (in-) dependence. These studies highlight the importance of considering the cell cycle dynamics for studies of chromosomal organization.
Collapse
Affiliation(s)
- Haoyue Zhang
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, Guangdong, China.
| | - Gerd A Blobel
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
21
|
Torres DE, Reckard AT, Klocko AD, Seidl MF. Nuclear genome organization in fungi: from gene folding to Rabl chromosomes. FEMS Microbiol Rev 2023; 47:fuad021. [PMID: 37197899 PMCID: PMC10246852 DOI: 10.1093/femsre/fuad021] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/28/2023] [Accepted: 05/08/2023] [Indexed: 05/19/2023] Open
Abstract
Comparative genomics has recently provided unprecedented insights into the biology and evolution of the fungal lineage. In the postgenomics era, a major research interest focuses now on detailing the functions of fungal genomes, i.e. how genomic information manifests into complex phenotypes. Emerging evidence across diverse eukaryotes has revealed that the organization of DNA within the nucleus is critically important. Here, we discuss the current knowledge on the fungal genome organization, from the association of chromosomes within the nucleus to topological structures at individual genes and the genetic factors required for this hierarchical organization. Chromosome conformation capture followed by high-throughput sequencing (Hi-C) has elucidated how fungal genomes are globally organized in Rabl configuration, in which centromere or telomere bundles are associated with opposite faces of the nuclear envelope. Further, fungal genomes are regionally organized into topologically associated domain-like (TAD-like) chromatin structures. We discuss how chromatin organization impacts the proper function of DNA-templated processes across the fungal genome. Nevertheless, this view is limited to a few fungal taxa given the paucity of fungal Hi-C experiments. We advocate for exploring genome organization across diverse fungal lineages to ensure the future understanding of the impact of nuclear organization on fungal genome function.
Collapse
Affiliation(s)
- David E Torres
- Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Laboratory of Phytopathology, Wageningen University and Research,Droevendaalsesteeg 4, 6708 PB Wageningen, The Netherlands
| | - Andrew T Reckard
- Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, 234 Centennial Hall, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918 USA
| | - Andrew D Klocko
- Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, 234 Centennial Hall, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918 USA
| | - Michael F Seidl
- Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| |
Collapse
|
22
|
Chen LF, Long HK, Park M, Swigut T, Boettiger AN, Wysocka J. Structural elements promote architectural stripe formation and facilitate ultra-long-range gene regulation at a human disease locus. Mol Cell 2023; 83:1446-1461.e6. [PMID: 36996812 DOI: 10.1016/j.molcel.2023.03.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/15/2023] [Accepted: 03/07/2023] [Indexed: 03/31/2023]
Abstract
Enhancer clusters overlapping disease-associated mutations in Pierre Robin sequence (PRS) patients regulate SOX9 expression at genomic distances over 1.25 Mb. We applied optical reconstruction of chromatin architecture (ORCA) imaging to trace 3D locus topology during PRS-enhancer activation. We observed pronounced changes in locus topology between cell types. Subsequent analysis of single-chromatin fiber traces revealed that these ensemble-average differences arise through changes in the frequency of commonly sampled topologies. We further identified two CTCF-bound elements, internal to the SOX9 topologically associating domain, which promote stripe formation, are positioned near the domain's 3D geometric center, and bridge enhancer-promoter contacts in a series of chromatin loops. Ablation of these elements results in diminished SOX9 expression and altered domain-wide contacts. Polymer models with uniform loading across the domain and frequent cohesin collisions recapitulate this multi-loop, centrally clustered geometry. Together, we provide mechanistic insights into architectural stripe formation and gene regulation over ultra-long genomic ranges.
Collapse
Affiliation(s)
- Liang-Fu Chen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Hannah Katherine Long
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Minhee Park
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Tomek Swigut
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Alistair Nicol Boettiger
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Joanna Wysocka
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute of Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
| |
Collapse
|
23
|
Zhang S, Übelmesser N, Barbieri M, Papantonis A. Enhancer-promoter contact formation requires RNAPII and antagonizes loop extrusion. Nat Genet 2023; 55:832-840. [PMID: 37012454 DOI: 10.1038/s41588-023-01364-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 03/06/2023] [Indexed: 04/05/2023]
Abstract
Homotypic chromatin interactions and loop extrusion are thought to be the two main drivers of mammalian chromosome folding. Here we tested the role of RNA polymerase II (RNAPII) across different scales of interphase chromatin organization in a cellular system allowing for its rapid, auxin-mediated degradation. We combined Micro-C and computational modeling to characterize subsets of loops differentially gained or lost upon RNAPII depletion. Gained loops, extrusion of which was antagonized by RNAPII, almost invariably formed by engaging new or rewired CTCF anchors. Lost loops selectively affected contacts between enhancers and promoters anchored by RNAPII, explaining the repression of most genes. Surprisingly, promoter-promoter interactions remained essentially unaffected by polymerase depletion, and cohesin occupancy was sustained. Together, our findings reconcile the role of RNAPII in transcription with its direct involvement in setting-up regulatory three-dimensional chromatin contacts genome wide, while also revealing an impact on cohesin loop extrusion.
Collapse
Affiliation(s)
- Shu Zhang
- Institute of Pathology, University Medical Center Göttingen, Göttingen, Germany
| | - Nadine Übelmesser
- Institute of Pathology, University Medical Center Göttingen, Göttingen, Germany
| | - Mariano Barbieri
- Institute of Pathology, University Medical Center Göttingen, Göttingen, Germany
| | - Argyris Papantonis
- Institute of Pathology, University Medical Center Göttingen, Göttingen, Germany.
| |
Collapse
|
24
|
Platania A, Erb C, Barbieri M, Molcrette B, Grandgirard E, de Kort MAC, Meaburn K, Taylor T, Shchuka VM, Kocanova S, Oliveira GM, Mitchell JA, Soutoglou E, Lenstra TL, Molina N, Papantonis A, Bystricky K, Sexton T. Competition between transcription and loop extrusion modulates promoter and enhancer dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.25.538222. [PMID: 37162887 PMCID: PMC10168261 DOI: 10.1101/2023.04.25.538222] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The spatiotemporal configuration of genes with distal regulatory elements, and the impact of chromatin mobility on transcription, remain unclear. Loop extrusion is an attractive model for bringing genetic elements together, but how this functionally interacts with transcription is also largely unknown. We combine live tracking of genomic loci and nascent transcripts with molecular dynamics simulations to assess the 4D arrangement of the Sox2 gene and its enhancer, in response to a battery of perturbations. We find that alterations in chromatin mobility, not promoter-enhancer distance, is more informative about transcriptional status. Active elements display more constrained mobility, consistent with confinement within specialized nuclear sites, and alterations in enhancer mobility distinguish poised from transcribing alleles. Strikingly, we find that whereas loop extrusion and transcription factor-mediated clustering contribute to promoter-enhancer proximity, they have antagonistic effects on chromatin dynamics. This provides an experimental framework for the underappreciated role of chromatin dynamics in genome regulation.
Collapse
Affiliation(s)
- Angeliki Platania
- Department of Functional Genomics and Cancer, 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
| | - Cathie Erb
- Department of Functional Genomics and Cancer, 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
| | - Mariano Barbieri
- Translational Epigenetics Group, Institute of Pathology, University Medical Centre Göttingen, Göttingen, Germany
| | - Bastien Molcrette
- Department of Functional Genomics and Cancer, 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
| | - Erwan Grandgirard
- Department of Functional Genomics and Cancer, 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
| | - Marit AC de Kort
- Division of Gene Regulation, the Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, the Netherlands
| | - Karen Meaburn
- Genome Damage and Stability Centre, Sussex University, School of Life Sciences, University of Sussex, Brighton, UK
| | - Tiegh Taylor
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M55 3G5, Canada
| | - Virlana M Shchuka
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M55 3G5, Canada
| | - Silvia Kocanova
- Molecular Cellular and Developmental Biology unit (MCD), Centre de Biologie Integrative (CBI) University of Toulouse Paul Sabatier, CNRS, 31062 Toulouse, France
| | - Guilherme Monteiro Oliveira
- Department of Functional Genomics and Cancer, 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
| | - Jennifer A Mitchell
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M55 3G5, Canada
| | - Evi Soutoglou
- Genome Damage and Stability Centre, Sussex University, School of Life Sciences, University of Sussex, Brighton, UK
| | - Tineke L Lenstra
- Division of Gene Regulation, the Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, the Netherlands
| | - Nacho Molina
- Department of Functional Genomics and Cancer, 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
| | - Argyris Papantonis
- Translational Epigenetics Group, Institute of Pathology, University Medical Centre Göttingen, Göttingen, Germany
| | - Kerstin Bystricky
- Molecular Cellular and Developmental Biology unit (MCD), Centre de Biologie Integrative (CBI) University of Toulouse Paul Sabatier, CNRS, 31062 Toulouse, France
- Institut Universitaire de France (IUF)
| | - Tom Sexton
- Department of Functional Genomics and Cancer, 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
| |
Collapse
|
25
|
Chiliński M, Lipiński J, Agarwal A, Ruan Y, Plewczynski D. Enhanced performance of gene expression predictive models with protein-mediated spatial chromatin interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.06.535849. [PMID: 37066361 PMCID: PMC10104055 DOI: 10.1101/2023.04.06.535849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
There have been multiple attempts to predict the expression of the genes based on the sequence, epigenetics, and various other factors. To improve those predictions, we have decided to investigate adding protein-specific 3D interactions that play a major role in the compensation of the chromatin structure in the cell nucleus. To achieve this, we have used the architecture of one of the state-of-the-art algorithms, ExPecto (J. Zhou et al., 2018), and investigated the changes in the model metrics upon adding the spatially relevant data. We have used ChIA-PET interactions that are mediated by cohesin (24 cell lines), CTCF (4 cell lines), and RNAPOL2 (4 cell lines). As the output of the study, we have developed the Spatial Gene Expression (SpEx) algorithm that shows statistically significant improvements in most cell lines.
Collapse
|
26
|
Karpinska MA, Oudelaar AM. The role of loop extrusion in enhancer-mediated gene activation. Curr Opin Genet Dev 2023; 79:102022. [PMID: 36842325 DOI: 10.1016/j.gde.2023.102022] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 01/13/2023] [Accepted: 01/25/2023] [Indexed: 02/28/2023]
Abstract
Gene expression patterns in complex multicellular organisms are regulated by enhancers, which communicate with their target gene promoters in three-dimensional (3D) chromatin structures. Despite advances in our understanding of the mechanisms that organize mammalian genomes into compartments and topologically associating domains (TADs), it is not well understood how specific interactions between enhancers and promoters are controlled in this 3D context. In this review, we give an overview of recent evidence that shows that a process of loop extrusion plays an important role in the regulation of enhancer-promoter communication and discuss recent insights into the molecular mechanism by which loop extrusion contributes to enhancer-mediated gene activation.
Collapse
Affiliation(s)
- Magdalena A Karpinska
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany. https://twitter.com/@MagdalenaKarp
| | | |
Collapse
|
27
|
Banigan EJ, Tang W, van den Berg AA, Stocsits RR, Wutz G, Brandão HB, Busslinger GA, Peters JM, Mirny LA. Transcription shapes 3D chromatin organization by interacting with loop extrusion. Proc Natl Acad Sci U S A 2023; 120:e2210480120. [PMID: 36897969 PMCID: PMC10089175 DOI: 10.1073/pnas.2210480120] [Citation(s) in RCA: 52] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 12/03/2022] [Indexed: 03/12/2023] Open
Abstract
Cohesin folds mammalian interphase chromosomes by extruding the chromatin fiber into numerous loops. "Loop extrusion" can be impeded by chromatin-bound factors, such as CTCF, which generates characteristic and functional chromatin organization patterns. It has been proposed that transcription relocalizes or interferes with cohesin and that active promoters are cohesin loading sites. However, the effects of transcription on cohesin have not been reconciled with observations of active extrusion by cohesin. To determine how transcription modulates extrusion, we studied mouse cells in which we could alter cohesin abundance, dynamics, and localization by genetic "knockouts" of the cohesin regulators CTCF and Wapl. Through Hi-C experiments, we discovered intricate, cohesin-dependent contact patterns near active genes. Chromatin organization around active genes exhibited hallmarks of interactions between transcribing RNA polymerases (RNAPs) and extruding cohesins. These observations could be reproduced by polymer simulations in which RNAPs were moving barriers to extrusion that obstructed, slowed, and pushed cohesins. The simulations predicted that preferential loading of cohesin at promoters is inconsistent with our experimental data. Additional ChIP-seq experiments showed that the putative cohesin loader Nipbl is not predominantly enriched at promoters. Therefore, we propose that cohesin is not preferentially loaded at promoters and that the barrier function of RNAP accounts for cohesin accumulation at active promoters. Altogether, we find that RNAP is an extrusion barrier that is not stationary, but rather, translocates and relocalizes cohesin. Loop extrusion and transcription might interact to dynamically generate and maintain gene interactions with regulatory elements and shape functional genomic organization.
Collapse
Affiliation(s)
- Edward J. Banigan
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Wen Tang
- Research Institute of Molecular Pathology, Vienna BioCenter1030Vienna, Austria
| | - Aafke A. van den Berg
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Roman R. Stocsits
- Research Institute of Molecular Pathology, Vienna BioCenter1030Vienna, Austria
| | - Gordana Wutz
- Research Institute of Molecular Pathology, Vienna BioCenter1030Vienna, Austria
| | - Hugo B. Brandão
- Graduate Program in Biophysics, Harvard University, Cambridge, MA02138
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA02139
- The Broad Institute of MIT and Harvard, Cambridge, MA02142
| | - Georg A. Busslinger
- Research Institute of Molecular Pathology, Vienna BioCenter1030Vienna, Austria
- Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna1090, Austria
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna1090, Austria
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology, Vienna BioCenter1030Vienna, Austria
| | - Leonid A. Mirny
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA02139
| |
Collapse
|
28
|
Roles of G4-DNA and G4-RNA in Class Switch Recombination and Additional Regulations in B-Lymphocytes. Molecules 2023; 28:molecules28031159. [PMID: 36770824 PMCID: PMC9921937 DOI: 10.3390/molecules28031159] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023] Open
Abstract
Mature B cells notably diversify immunoglobulin (Ig) production through class switch recombination (CSR), allowing the junction of distant "switch" (S) regions. CSR is initiated by activation-induced deaminase (AID), which targets cytosines adequately exposed within single-stranded DNA of transcribed targeted S regions, with a specific affinity for WRCY motifs. In mammals, G-rich sequences are additionally present in S regions, forming canonical G-quadruplexes (G4s) DNA structures, which favor CSR. Small molecules interacting with G4-DNA (G4 ligands), proved able to regulate CSR in B lymphocytes, either positively (such as for nucleoside diphosphate kinase isoforms) or negatively (such as for RHPS4). G4-DNA is also implicated in the control of transcription, and due to their impact on both CSR and transcriptional regulation, G4-rich sequences likely play a role in the natural history of B cell malignancies. Since G4-DNA stands at multiple locations in the genome, notably within oncogene promoters, it remains to be clarified how it can more specifically promote legitimate CSR in physiology, rather than pathogenic translocation. The specific regulatory role of G4 structures in transcribed DNA and/or in corresponding transcripts and recombination hereby appears as a major issue for understanding immune responses and lymphomagenesis.
Collapse
|
29
|
Kaushal A, Dorier J, Wang B, Mohana G, Taschner M, Cousin P, Waridel P, Iseli C, Semenova A, Restrepo S, Guex N, Aiden EL, Gambetta MC. Essential role of Cp190 in physical and regulatory boundary formation. SCIENCE ADVANCES 2022; 8:eabl8834. [PMID: 35559678 PMCID: PMC9106302 DOI: 10.1126/sciadv.abl8834] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 04/01/2022] [Indexed: 05/31/2023]
Abstract
Boundaries in animal genomes delimit contact domains with enhanced internal contact frequencies and have debated functions in limiting regulatory cross-talk between domains and guiding enhancers to target promoters. Most mammalian boundaries form by stalling of chromosomal loop-extruding cohesin by CTCF, but most Drosophila boundaries form CTCF independently. However, how CTCF-independent boundaries form and function remains largely unexplored. Here, we assess genome folding and developmental gene expression in fly embryos lacking the ubiquitous boundary-associated factor Cp190. We find that sequence-specific DNA binding proteins such as CTCF and Su(Hw) directly interact with and recruit Cp190 to form most promoter-distal boundaries. Cp190 is essential for early development and prevents regulatory cross-talk between specific gene loci that pattern the embryo. Cp190 was, in contrast, dispensable for long-range enhancer-promoter communication at tested loci. Cp190 is thus currently the major player in fly boundary formation and function, revealing that diverse mechanisms evolved to partition genomes into independent regulatory domains.
Collapse
Affiliation(s)
- Anjali Kaushal
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Julien Dorier
- Bioinformatics Competence Center, University of Lausanne, 1015 Lausanne, Switzerland
| | - Bihan Wang
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Giriram Mohana
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Michael Taschner
- Department of Fundamental Microbiology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Pascal Cousin
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Patrice Waridel
- Protein Analysis Facility, University of Lausanne, 1015 Lausanne, Switzerland
| | - Christian Iseli
- Bioinformatics Competence Center, University of Lausanne, 1015 Lausanne, Switzerland
| | - Anastasiia Semenova
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Simon Restrepo
- arcoris bio AG, Lüssirainstrasse 52, 6300 Zug, Switzerland
| | - Nicolas Guex
- Bioinformatics Competence Center, University of Lausanne, 1015 Lausanne, Switzerland
| | - Erez Lieberman Aiden
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- National Institute of Genetics, 1111 Yaya, Mishima, Shizuoka 411-8540, Japan
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech, Pudong 20120, China
| | | |
Collapse
|