101
|
Gene Regulation Knows Its Boundaries. Trends Genet 2019; 35:883-885. [DOI: 10.1016/j.tig.2019.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 09/18/2019] [Indexed: 12/29/2022]
|
102
|
Oudelaar AM, Harrold CL, Hanssen LLP, Telenius JM, Higgs DR, Hughes JR. A revised model for promoter competition based on multi-way chromatin interactions at the α-globin locus. Nat Commun 2019; 10:5412. [PMID: 31776347 PMCID: PMC6881440 DOI: 10.1038/s41467-019-13404-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 11/05/2019] [Indexed: 11/25/2022] Open
Abstract
Specific communication between gene promoters and enhancers is critical for accurate regulation of gene expression. However, it remains unclear how specific interactions between multiple regulatory elements contained within a single chromatin domain are coordinated. Recent technological advances which can detect multi-way chromatin interactions at single alleles can provide insights into how multiple regulatory elements cooperate or compete for transcriptional activation. Here, we use such an approach to investigate how interactions of the α-globin enhancers are distributed between multiple promoters in a mouse model in which the α-globin domain is extended to include several additional genes. Our data show that gene promoters do not form mutually exclusive interactions with enhancers, but all interact simultaneously in a single complex. These findings suggest that promoters do not structurally compete for interactions with enhancers, but form a regulatory hub structure, which is consistent with recent models of transcriptional activation occurring in non-membrane bound nuclear compartments.
Collapse
Affiliation(s)
- A Marieke Oudelaar
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Caroline L Harrold
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Lars L P Hanssen
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jelena M Telenius
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Douglas R Higgs
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jim R Hughes
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
- MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
| |
Collapse
|
103
|
de Wit E. TADs as the Caller Calls Them. J Mol Biol 2019; 432:638-642. [PMID: 31654669 DOI: 10.1016/j.jmb.2019.09.026] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/06/2019] [Accepted: 09/25/2019] [Indexed: 11/19/2022]
Abstract
Developments in proximity ligation methods and sequencing technologies have provided high-resolution views of the organization of the genome inside the nucleus. A prominent feature of Hi-C maps is regions of increased self-interaction called topologically associating domains (TADs). Despite the strong evolutionary conservation and clear link with gene expression, the exact role of TADs and even their definition remains debatable. Here, I review the discovery of TADs, how they are commonly identified, and the mechanisms that lead to their formation. Furthermore, I discuss recent results that have created a more nuanced view of the role of TADs in the regulation of genes. In light of this, I propose that when we define TADs, we also consider the mechanisms that shape them.
Collapse
Affiliation(s)
- Elzo de Wit
- Division of Gene Regulation, Oncode Institute and Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam, 1066CX, the Netherlands.
| |
Collapse
|
104
|
Ghavi-Helm Y. Functional Consequences of Chromosomal Rearrangements on Gene Expression: Not So Deleterious After All? J Mol Biol 2019; 432:665-675. [PMID: 31626801 DOI: 10.1016/j.jmb.2019.09.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 09/04/2019] [Accepted: 09/12/2019] [Indexed: 12/14/2022]
Abstract
Chromosomes are folded and organized into topologically associating domains (TADs) which provide a framework for the interaction of enhancers with the promoter of their target gene(s). Structural rearrangements observed during evolution or in disease contexts suggest that changes in genome organization strongly affect gene expression and can have drastic phenotypic effects. In this review, I will discuss how recent genomic engineering experiments reveal a more contrasted picture, suggesting that TADs are important but not always essential for gene expression regulation.
Collapse
Affiliation(s)
- Yad Ghavi-Helm
- Institut de Génomique Fonctionnelle de Lyon, Univ Lyon, CNRS UMR 5242, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, 46 Allée D'Italie, F-69364 Lyon, France.
| |
Collapse
|
105
|
The Role of Insulation in Patterning Gene Expression. Genes (Basel) 2019; 10:genes10100767. [PMID: 31569427 PMCID: PMC6827083 DOI: 10.3390/genes10100767] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 12/16/2022] Open
Abstract
Development is orchestrated by regulatory elements that turn genes ON or OFF in precise spatial and temporal patterns. Many safety mechanisms prevent inappropriate action of a regulatory element on the wrong gene promoter. In flies and mammals, dedicated DNA elements (insulators) recruit protein factors (insulator binding proteins, or IBPs) to shield promoters from regulatory elements. In mammals, a single IBP called CCCTC-binding factor (CTCF) is known, whereas genetic and biochemical analyses in Drosophila have identified a larger repertoire of IBPs. How insulators function at the molecular level is not fully understood, but it is currently thought that they fold chromosomes into conformations that affect regulatory element-promoter communication. Here, we review the discovery of insulators and describe their properties. We discuss recent genetic studies in flies and mice to address the question: Is gene insulation important for animal development? Comparing and contrasting observations in these two species reveal that they have different requirements for insulation, but that insulation is a conserved and critical gene regulation strategy.
Collapse
|
106
|
Tycko J, Wainberg M, Marinov GK, Ursu O, Hess GT, Ego BK, Aradhana, Li A, Truong A, Trevino AE, Spees K, Yao D, Kaplow IM, Greenside PG, Morgens DW, Phanstiel DH, Snyder MP, Bintu L, Greenleaf WJ, Kundaje A, Bassik MC. Mitigation of off-target toxicity in CRISPR-Cas9 screens for essential non-coding elements. Nat Commun 2019; 10:4063. [PMID: 31492858 PMCID: PMC6731277 DOI: 10.1038/s41467-019-11955-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 08/07/2019] [Indexed: 12/26/2022] Open
Abstract
Pooled CRISPR-Cas9 screens are a powerful method for functionally characterizing regulatory elements in the non-coding genome, but off-target effects in these experiments have not been systematically evaluated. Here, we investigate Cas9, dCas9, and CRISPRi/a off-target activity in screens for essential regulatory elements. The sgRNAs with the largest effects in genome-scale screens for essential CTCF loop anchors in K562 cells were not single guide RNAs (sgRNAs) that disrupted gene expression near the on-target CTCF anchor. Rather, these sgRNAs had high off-target activity that, while only weakly correlated with absolute off-target site number, could be predicted by the recently developed GuideScan specificity score. Screens conducted in parallel with CRISPRi/a, which do not induce double-stranded DNA breaks, revealed that a distinct set of off-targets also cause strong confounding fitness effects with these epigenome-editing tools. Promisingly, filtering of CRISPRi libraries using GuideScan specificity scores removed these confounded sgRNAs and enabled identification of essential regulatory elements.
Collapse
Affiliation(s)
- Josh Tycko
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Michael Wainberg
- Department of Computer Science, Stanford University, Stanford, CA, 94305, USA
| | - Georgi K Marinov
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Oana Ursu
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Gaelen T Hess
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Braeden K Ego
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Aradhana
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Amy Li
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Alisa Truong
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Alexandro E Trevino
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA, 94305, USA
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Kaitlyn Spees
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - David Yao
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Irene M Kaplow
- Department of Computer Science, Stanford University, Stanford, CA, 94305, USA
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Peyton G Greenside
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
- Program in Biomedical Informatics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - David W Morgens
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Douglas H Phanstiel
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC, 27599, USA
- Thurston Arthritis Research Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Michael P Snyder
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Lacramioara Bintu
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - William J Greenleaf
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA.
- Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA.
| | - Anshul Kundaje
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA.
- Department of Computer Science, Stanford University, Stanford, CA, 94305, USA.
| | - Michael C Bassik
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA.
- Chemistry, Engineering, and Medicine for Human Health (ChEM-H), Stanford University, Stanford, CA, 94305, USA.
| |
Collapse
|
107
|
Geeven G, Teunissen H, de Laat W, de Wit E. peakC: a flexible, non-parametric peak calling package for 4C and Capture-C data. Nucleic Acids Res 2019; 46:e91. [PMID: 29800273 PMCID: PMC6125690 DOI: 10.1093/nar/gky443] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/13/2018] [Indexed: 11/14/2022] Open
Abstract
It is becoming increasingly clear that chromosome organization plays an important role in gene regulation. High-resolution methods such as 4C, Capture-C and promoter capture Hi-C (PCHiC) enable the study of chromatin loops such as those formed between promoters and enhancers or CTCF/cohesin binding sites. An important aspect of 4C/Capture-C/PCHiC analyses is the reliable identification of chromatin loops, preferably not based on visual inspection of a DNA contact profile, but on reproducible statistical analysis that robustly scores interaction peaks in the non-uniform contact background. Here, we present peakC, an R package for the analysis of 4C/Capture-C/PCHiC data. We generated 4C data for 13 viewpoints in two tissues in at least triplicate to test our methods. We developed a non-parametric peak caller based on rank-products. Sampling analysis shows that not read depth but template quality is the most important determinant of success in 4C experiments. By performing peak calling on single experiments we show that the peak calling results are similar to the replicate experiments, but that false positive rates are significantly reduced by performing replicates. Our software is user-friendly and enables robust peak calling for one-vs-all chromosome capture experiments. peakC is available at: https://github.com/deWitLab/peakC.
Collapse
Affiliation(s)
- Geert Geeven
- Oncode Institute, Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - Hans Teunissen
- Oncode Institute and Division of Gene Regulation, the Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| | - Wouter de Laat
- Oncode Institute, Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - Elzo de Wit
- Oncode Institute and Division of Gene Regulation, the Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| |
Collapse
|
108
|
Lee HK, Willi M, Shin HY, Liu C, Hennighausen L. Progressing super-enhancer landscape during mammary differentiation controls tissue-specific gene regulation. Nucleic Acids Res 2019; 46:10796-10809. [PMID: 30285185 PMCID: PMC6237736 DOI: 10.1093/nar/gky891] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 09/20/2018] [Indexed: 12/15/2022] Open
Abstract
The mammary luminal lineage relies on the common cytokine-sensing transcription factor STAT5 to establish super-enhancers during pregnancy and initiate a genetic program that activates milk production. As pups grow, the greatly increasing demand for milk requires progressive differentiation of mammary cells with advancing lactation. Here we investigate how persistent hormonal exposure during lactation shapes an evolving enhancer landscape and impacts the biology of mammary cells. Employing ChIP-seq, we uncover a changing transcription factor occupancy at mammary enhancers, suggesting that their activities evolve with advancing differentiation. Using mouse genetics, we demonstrate that the functions of individual enhancers within the Wap super-enhancer evolve as lactation progresses. Most profoundly, a seed enhancer, which is mandatory for the activation of the Wap super-enhancer during pregnancy, is not required during lactation, suggesting compensatory flexibility. Combinatorial deletions of structurally equivalent constituent enhancers demonstrated differentiation-specific compensatory activities during lactation. We also demonstrate that the Wap super-enhancer, which is built on STAT5 and other common transcription factors, retains its exquisite mammary specificity when placed into globally permissive chromatin, suggesting a limited role of chromatin in controlling cell specificity. Our studies unveil a previously unrecognized progressive enhancer landscape where structurally equivalent components serve unique and differentiation-specific functions.
Collapse
Affiliation(s)
- Hye Kyung Lee
- Laboratory of Genetics and Physiology, National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health, Bethesda, MD 20892, USA
| | - Michaela Willi
- Laboratory of Genetics and Physiology, National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health, Bethesda, MD 20892, USA
| | - Ha Youn Shin
- Department of Biomedical Science and Engineering, Konkuk University, Seoul 05029, Republic of Korea
| | - Chengyu Liu
- Transgenic Core, National Heart, Lung, and Blood Institute, US National Institutes of Health, Bethesda, MD 20892, USA
| | - Lothar Hennighausen
- Laboratory of Genetics and Physiology, National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
109
|
Mutational Patterns in Metastatic Cutaneous Squamous Cell Carcinoma. J Invest Dermatol 2019; 139:1449-1458.e1. [DOI: 10.1016/j.jid.2019.01.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 01/02/2019] [Accepted: 01/02/2019] [Indexed: 01/01/2023]
|
110
|
Lazniewski M, Dawson WK, Rusek AM, Plewczynski D. One protein to rule them all: The role of CCCTC-binding factor in shaping human genome in health and disease. Semin Cell Dev Biol 2019; 90:114-127. [PMID: 30096365 PMCID: PMC6642822 DOI: 10.1016/j.semcdb.2018.08.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 08/06/2018] [Indexed: 12/12/2022]
Abstract
The eukaryotic genome, constituting several billion base pairs, must be contracted to fit within the volume of a nucleus where the diameter is on the scale of μm. The 3D structure and packing of such a long sequence cannot be left to pure chance, as DNA must be efficiently used for its primary roles as a matrix for transcription and replication. In recent years, methods like chromatin conformation capture (including 3C, 4C, Hi-C, ChIA-PET and Multi-ChIA) and optical microscopy have advanced substantially and have shed new light on how eukaryotic genomes are hierarchically organized; first into 10-nm fiber, next into DNA loops, topologically associated domains and finally into interphase or mitotic chromosomes. This knowledge has allowed us to revise our understanding regarding the mechanisms governing the process of DNA organization. Mounting experimental evidence suggests that the key element in the formation of loops is the binding of the CCCTC-binding factor (CTCF) to DNA; a protein that can be referred to as the chief organizer of the genome. However, CTCF does not work alone but in cooperation with other proteins, such as cohesin or Yin Yang 1 (YY1). In this short review, we briefly describe our current understanding of the structure of eukaryotic genomes, how they are established and how the formation of DNA loops can influence gene expression. We discuss the recent discoveries describing the 3D structure of the CTCF-DNA complex and the role of CTCF in establishing genome structure. Finally, we briefly explain how various genetic disorders might arise as a consequence of mutations in the CTCF target sequence or alteration of genomic imprinting.
Collapse
Affiliation(s)
- Michal Lazniewski
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland; Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1, 02-097 Warsaw, Poland
| | - Wayne K Dawson
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland; Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 103-8657, Japan
| | - Anna Maria Rusek
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland; Clinical Molecular Biology Department, Medical University of Bialystok, Bialystok, Poland
| | - Dariusz Plewczynski
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland; Centre for Innovative Research, Medical University of Bialystok, Bialystok, Poland; Faculty of Mathematics and Information Science, Warsaw University of Technology, Warsaw, Poland.
| |
Collapse
|
111
|
Krumm A, Duan Z. Understanding the 3D genome: Emerging impacts on human disease. Semin Cell Dev Biol 2019; 90:62-77. [PMID: 29990539 PMCID: PMC6329682 DOI: 10.1016/j.semcdb.2018.07.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/03/2018] [Indexed: 12/13/2022]
Abstract
Recent burst of new technologies that allow for quantitatively delineating chromatin structure has greatly expanded our understanding of how the genome is organized in the three-dimensional (3D) space of the nucleus. It is now clear that the hierarchical organization of the eukaryotic genome critically impacts nuclear activities such as transcription, replication, as well as cellular and developmental events such as cell cycle, cell fate decision and embryonic development. In this review, we discuss new insights into how the structural features of the 3D genome hierarchy are established and maintained, how this hierarchy undergoes dynamic rearrangement during normal development and how its perturbation will lead to human disease, highlighting the accumulating evidence that links the diverse 3D genome architecture components to a multitude of human diseases and the emerging mechanisms by which 3D genome derangement causes disease phenotypes.
Collapse
Affiliation(s)
- Anton Krumm
- Department of Microbiology, University of Washington, USA.
| | - Zhijun Duan
- Institute for Stem Cell and Regenerative Medicine, University of Washington, USA; Division of Hematology, Department of Medicine, University of Washington, USA.
| |
Collapse
|
112
|
van Steensel B, Furlong EEM. The role of transcription in shaping the spatial organization of the genome. Nat Rev Mol Cell Biol 2019; 20:327-337. [PMID: 30886333 PMCID: PMC7116054 DOI: 10.1038/s41580-019-0114-6] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The spatial organization of the genome into compartments and topologically associated domains can have an important role in the regulation of gene expression. But could gene expression conversely regulate genome organization? Here, we review recent studies that assessed the requirement of transcription and/or the transcription machinery for the establishment or maintenance of genome topology. The results reveal different requirements at different genomic scales. Transcription is generally not required for higher-level genome compartmentalization, has only moderate effects on domain organization and is not sufficient to create new domain boundaries. However, on a finer scale, transcripts or transcription does seem to have a role in the formation of subcompartments and subdomains and in stabilizing enhancer-promoter interactions. Recent evidence suggests a dynamic, reciprocal interplay between fine-scale genome organization and transcription, in which each is able to modulate or reinforce the activity of the other.
Collapse
Affiliation(s)
- Bas van Steensel
- Division of Gene Regulation and Oncode Institute, Netherlands Cancer Institute, Amsterdam, Netherlands.
- Department of Cell Biology, Erasmus University Medical Centre, Rotterdam, Netherlands.
| | - Eileen E M Furlong
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany.
| |
Collapse
|
113
|
Schoenfelder S, Fraser P. Long-range enhancer–promoter contacts in gene expression control. Nat Rev Genet 2019; 20:437-455. [DOI: 10.1038/s41576-019-0128-0] [Citation(s) in RCA: 486] [Impact Index Per Article: 97.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
114
|
Braccioli L, de Wit E. CTCF: a Swiss-army knife for genome organization and transcription regulation. Essays Biochem 2019; 63:157-165. [PMID: 30940740 DOI: 10.1042/ebc20180069] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/08/2019] [Accepted: 03/11/2019] [Indexed: 12/11/2022]
Abstract
Orchestrating vertebrate genomes require a complex interplay between the linear composition of the genome and its 3D organization inside the nucleus. This requires the function of specialized proteins, able to tune various aspects of genome organization and gene regulation. The CCCTC-binding factor (CTCF) is a DNA binding factor capable of regulating not only the 3D genome organization, but also key aspects of gene expression, including transcription activation and repression, RNA splicing, and enhancer/promoter insulation. A growing body of evidence proposes that CTCF, together with cohesin contributes to DNA loop formation and 3D genome organization. CTCF binding sites are mutation hotspots in cancer, while mutations in CTCF itself lead to intellectual disabilities, emphasizing its importance in disease etiology. In this review we cover various aspects of CTCF function, revealing the polyvalence of this factor as a highly diversified tool for vertebrate genome organization and transcription regulation.
Collapse
Affiliation(s)
- Luca Braccioli
- Oncode Institute and Division of Gene Regulation, the Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, the Netherlands
| | - Elzo de Wit
- Oncode Institute and Division of Gene Regulation, the Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, the Netherlands
| |
Collapse
|
115
|
Abstract
Vast repertoires of unique antigen receptors are created in developing lymphocytes. The antigen receptor loci contain many variable (V), diversity (D), and joining (J) gene segments that are arrayed across very large genomic expanses and are joined to form variable-region exons. This process creates the potential for an organism to respond to large numbers of different pathogens. Here, we consider the underlying molecular mechanisms that favor some V genes for recombination prior to selection of the final antigen receptor repertoire. We discuss chromatin structures that form in antigen receptor loci to permit spatial proximity among the V, D, and J gene segments and how these relate to the generation of antigen receptor diversity.
Collapse
Affiliation(s)
- Amy L Kenter
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL, 60612-7344, USA
| | - Ann J Feeney
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| |
Collapse
|
116
|
See YX, Wang BZ, Fullwood MJ. Chromatin Interactions and Regulatory Elements in Cancer: From Bench to Bedside. Trends Genet 2019; 35:145-158. [DOI: 10.1016/j.tig.2018.11.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/14/2018] [Accepted: 11/27/2018] [Indexed: 12/16/2022]
|
117
|
Sun F, Chronis C, Kronenberg M, Chen XF, Su T, Lay FD, Plath K, Kurdistani SK, Carey MF. Promoter-Enhancer Communication Occurs Primarily within Insulated Neighborhoods. Mol Cell 2019; 73:250-263.e5. [PMID: 30527662 PMCID: PMC6338517 DOI: 10.1016/j.molcel.2018.10.039] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 07/09/2018] [Accepted: 10/25/2018] [Indexed: 12/09/2022]
Abstract
Metazoan chromosomes are sequentially partitioned into topologically associating domains (TADs) and then into smaller sub-domains. One class of sub-domains, insulated neighborhoods, are proposed to spatially sequester and insulate the enclosed genes through self-association and chromatin looping. However, it has not been determined functionally whether promoter-enhancer interactions and gene regulation are broadly restricted to within these loops. Here, we employed published datasets from murine embryonic stem cells (mESCs) to identify insulated neighborhoods that confine promoter-enhancer interactions and demarcate gene regulatory regions. To directly address the functionality of these regions, we depleted estrogen-related receptor β (Esrrb), which binds the Mediator co-activator complex, to impair enhancers of genes within 222 insulated neighborhoods without causing mESC differentiation. Esrrb depletion reduces Mediator binding, promoter-enhancer looping, and expression of both nascent RNA and mRNA within the insulated neighborhoods without significantly affecting the flanking genes. Our data indicate that insulated neighborhoods represent functional regulons in mammalian genomes.
Collapse
MESH Headings
- Animals
- Binding Sites
- CCCTC-Binding Factor/genetics
- CCCTC-Binding Factor/metabolism
- Cell Cycle Proteins/genetics
- Cell Cycle Proteins/metabolism
- Cell Line
- Chromosomal Proteins, Non-Histone/genetics
- Chromosomal Proteins, Non-Histone/metabolism
- Chromosomes, Mammalian
- Databases, Genetic
- Down-Regulation
- Enhancer Elements, Genetic
- Insulator Elements
- Mice
- Mouse Embryonic Stem Cells/physiology
- Promoter Regions, Genetic
- Protein Binding
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Transcription, Genetic
- Cohesins
Collapse
Affiliation(s)
- Fei Sun
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
| | - Constantinos Chronis
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
| | - Michael Kronenberg
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
| | - Xiao-Fen Chen
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
| | - Trent Su
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
| | - Fides D Lay
- Department of Molecular, Cellular and Developmental Biology, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Kathrin Plath
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
| | - Siavash K Kurdistani
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
| | - Michael F Carey
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1737, USA.
| |
Collapse
|
118
|
Integrative view on how erythropoietin signaling controls transcription patterns in erythroid cells. Curr Opin Hematol 2019; 25:189-195. [PMID: 29389768 DOI: 10.1097/moh.0000000000000415] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PURPOSE OF REVIEW Erythropoietin (EPO) is necessary and sufficient to trigger dynamic transcriptional patterns that drive the differentiation of erythroid precursor cells into mature, enucleated red cells. Because the molecular cloning and Food and Drug Administration approval for the therapeutic use of EPO over 30 years ago, a detailed understanding of how EPO works has advanced substantially. Yet, the precise epigenetic and transcriptional mechanisms by which EPO signaling controls erythroid expression patterns remains poorly understood. This review focuses on the current state of erythroid biology in regards to EPO signaling from human genetics and functional genomics perspectives. RECENT FINDINGS The goal of this review is to provide an integrative view of the gene regulatory underpinnings for erythroid expression patterns that are dynamically shaped during erythroid differentiation. Here, we highlight vignettes connecting recent insights into a genome-wide association study linking an EPO mutation to anemia, a study linking EPO-signaling to signal transducer and activator of transcription 5 (STAT5) chromatin occupancy and enhancers, and studies that examine the molecular mechanisms driving topological chromatin organization in erythroid cells. SUMMARY The genetic, epigenetic, and gene regulatory mechanisms underlying how hormone signal transduction influences erythroid gene expression remains only partly understood. A detailed understanding of these molecular pathways and how they intersect with one another will provide the basis for novel strategies to treat anemia and potentially other hematological diseases. As new regulators and signal transducers of EPO-signaling continue to emerge, new clinically relevant targets may be identified that improve the specificity and effectiveness of EPO therapy.
Collapse
|
119
|
Raviram R, Rocha PP, Luo VM, Swanzey E, Miraldi ER, Chuong EB, Feschotte C, Bonneau R, Skok JA. Analysis of 3D genomic interactions identifies candidate host genes that transposable elements potentially regulate. Genome Biol 2018; 19:216. [PMID: 30541598 PMCID: PMC6292174 DOI: 10.1186/s13059-018-1598-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 11/28/2018] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The organization of chromatin in the nucleus plays an essential role in gene regulation. About half of the mammalian genome comprises transposable elements. Given their repetitive nature, reads associated with these elements are generally discarded or randomly distributed among elements of the same type in genome-wide analyses. Thus, it is challenging to identify the activities and properties of individual transposons. As a result, we only have a partial understanding of how transposons contribute to chromatin folding and how they impact gene regulation. RESULTS Using PCR and Capture-based chromosome conformation capture (3C) approaches, collectively called 4Tran, we take advantage of the repetitive nature of transposons to capture interactions from multiple copies of endogenous retrovirus (ERVs) in the human and mouse genomes. With 4Tran-PCR, reads are selectively mapped to unique regions in the genome. This enables the identification of transposable element interaction profiles for individual ERV families and integration events specific to particular genomes. With this approach, we demonstrate that transposons engage in long-range intra-chromosomal interactions guided by the separation of chromosomes into A and B compartments as well as topologically associated domains (TADs). In contrast to 4Tran-PCR, Capture-4Tran can uniquely identify both ends of an interaction that involve retroviral repeat sequences, providing a powerful tool for uncovering the individual transposable element insertions that interact with and potentially regulate target genes. CONCLUSIONS 4Tran provides new insight into the manner in which transposons contribute to chromosome architecture and identifies target genes that transposable elements can potentially control.
Collapse
Affiliation(s)
- Ramya Raviram
- Department of Pathology, New York University School of Medicine, New York, NY 10016 USA
- Department of Biology, New York University, New York, NY 10003 USA
- Ludwig Institute for Cancer Research, La Jolla, CA USA
| | - Pedro P. Rocha
- Department of Pathology, New York University School of Medicine, New York, NY 10016 USA
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892 USA
| | - Vincent M. Luo
- Department of Pathology, New York University School of Medicine, New York, NY 10016 USA
- Department of Biology, New York University, New York, NY 10003 USA
| | - Emily Swanzey
- Department of Developmental Genetics, New York University School of Medicine, New York, NY 10016 USA
| | - Emily R. Miraldi
- Department of Biology, New York University, New York, NY 10003 USA
- Department of Computer Science, Courant Institute of Mathematical Sciences, New York, NY 10003 USA
- Simons Center for Data Analysis, New York, NY 10010 USA
- Divisions of Immunobiology and Biomedical Informatics, Cincinnati Children’s Hospital, Cincinnati, OH 45229 USA
| | - Edward B. Chuong
- BioFrontiers Institute, Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Cédric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850 USA
| | - Richard Bonneau
- Department of Biology, New York University, New York, NY 10003 USA
- Department of Computer Science, Courant Institute of Mathematical Sciences, New York, NY 10003 USA
- Simons Center for Data Analysis, New York, NY 10010 USA
| | - Jane A. Skok
- Department of Pathology, New York University School of Medicine, New York, NY 10016 USA
| |
Collapse
|
120
|
Vermunt MW, Zhang D, Blobel GA. The interdependence of gene-regulatory elements and the 3D genome. J Cell Biol 2018; 218:12-26. [PMID: 30442643 PMCID: PMC6314554 DOI: 10.1083/jcb.201809040] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/29/2018] [Accepted: 10/29/2018] [Indexed: 01/12/2023] Open
Abstract
Vermunt et al. discuss the relationship between gene-regulatory elements and nuclear architectural features in transcription. Imaging studies, high-resolution chromatin conformation maps, and genome-wide occupancy data of architectural proteins have revealed that genome topology is tightly intertwined with gene expression. Cross-talk between gene-regulatory elements is often organized within insulated neighborhoods, and regulatory cues that induce transcriptional changes can reshape chromatin folding patterns and gene positioning within the nucleus. The cause–consequence relationship of genome architecture and gene expression is intricate, and its molecular mechanisms are under intense investigation. Here, we review the interdependency of transcription and genome organization with emphasis on enhancer–promoter contacts in gene regulation.
Collapse
Affiliation(s)
- Marit W Vermunt
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA
| | - Di Zhang
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Gerd A Blobel
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA .,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
121
|
Guo X, Dean A. CRISPR/Cas9 offers a new tool for studying the role of chromatin architecture in disease pathogenesis. Genome Biol 2018; 19:185. [PMID: 30400943 PMCID: PMC6219166 DOI: 10.1186/s13059-018-1569-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
A recent study used CRISPR/Cas9 to reveal long-range looping between disease-related genes and their regulatory elements that is mediated by the CCCTC-binding factor (CTCF) in prostate cancer.
Collapse
Affiliation(s)
- Xiang Guo
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Ann Dean
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
| |
Collapse
|
122
|
Oudelaar AM, Davies JOJ, Hanssen LLP, Telenius JM, Schwessinger R, Liu Y, Brown JM, Downes DJ, Chiariello AM, Bianco S, Nicodemi M, Buckle VJ, Dekker J, Higgs DR, Hughes JR. Single-allele chromatin interactions identify regulatory hubs in dynamic compartmentalized domains. Nat Genet 2018; 50:1744-1751. [PMID: 30374068 PMCID: PMC6265079 DOI: 10.1038/s41588-018-0253-2] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 09/07/2018] [Indexed: 11/09/2022]
Abstract
The promoters of mammalian genes are commonly regulated by multiple distal enhancers, which physically interact within discrete chromatin domains. How such domains form and how the regulatory elements within them interact in single cells is not understood. To address this we developed Tri-C, a new Chromosome Conformation Capture (3C) approach to identify concurrent chromatin interactions at individual alleles. Analysis by Tri-C reveals heterogeneous patterns of single-allele interactions between CTCF boundary elements, indicating that the formation of chromatin domains likely results from a dynamic process. Within these domains, we observe specific higher-order structures involving simultaneous interactions between multiple enhancers and promoters. Such regulatory hubs provide a structural basis for understanding how multiple cis-regulatory elements act together to establish robust regulation of gene expression.
Collapse
Affiliation(s)
- A Marieke Oudelaar
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - James O J Davies
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Lars L P Hanssen
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jelena M Telenius
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Ron Schwessinger
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Yu Liu
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Jill M Brown
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Damien J Downes
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Andrea M Chiariello
- Dipartimento di Fisica, Università di Napoli Federico II, and INFN Napoli, Complesso di Monte Sant'Angelo, Naples, Italy
| | - Simona Bianco
- Dipartimento di Fisica, Università di Napoli Federico II, and INFN Napoli, Complesso di Monte Sant'Angelo, Naples, Italy
| | - Mario Nicodemi
- Dipartimento di Fisica, Università di Napoli Federico II, and INFN Napoli, Complesso di Monte Sant'Angelo, Naples, Italy
| | - Veronica J Buckle
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Job Dekker
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Douglas R Higgs
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jim R Hughes
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK. .,MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
| |
Collapse
|
123
|
Winter DJ, Ganley ARD, Young CA, Liachko I, Schardl CL, Dupont PY, Berry D, Ram A, Scott B, Cox MP. Repeat elements organise 3D genome structure and mediate transcription in the filamentous fungus Epichloë festucae. PLoS Genet 2018; 14:e1007467. [PMID: 30356280 PMCID: PMC6218096 DOI: 10.1371/journal.pgen.1007467] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 11/05/2018] [Accepted: 08/27/2018] [Indexed: 11/18/2022] Open
Abstract
Structural features of genomes, including the three-dimensional arrangement of DNA in the nucleus, are increasingly seen as key contributors to the regulation of gene expression. However, studies on how genome structure and nuclear organisation influence transcription have so far been limited to a handful of model species. This narrow focus limits our ability to draw general conclusions about the ways in which three-dimensional structures are encoded, and to integrate information from three-dimensional data to address a broader gamut of biological questions. Here, we generate a complete and gapless genome sequence for the filamentous fungus, Epichloë festucae. We use Hi-C data to examine the three-dimensional organisation of the genome, and RNA-seq data to investigate how Epichloë genome structure contributes to the suite of transcriptional changes needed to maintain symbiotic relationships with the grass host. Our results reveal a genome in which very repeat-rich blocks of DNA with discrete boundaries are interspersed by gene-rich sequences that are almost repeat-free. In contrast to other species reported to date, the three-dimensional structure of the genome is anchored by these repeat blocks, which act to isolate transcription in neighbouring gene-rich regions. Genes that are differentially expressed in planta are enriched near the boundaries of these repeat-rich blocks, suggesting that their three-dimensional orientation partly encodes and regulates the symbiotic relationship formed by this organism.
Collapse
Affiliation(s)
- David J. Winter
- Statistics and Bioinformatics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
- The Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
| | - Austen R. D. Ganley
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Carolyn A. Young
- Noble Research Institute, LLC, Ardmore, Oklahoma, United States of America
| | - Ivan Liachko
- Phase Genomics Inc, Seattle, Washington, United States of America
| | - Christopher L. Schardl
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Pierre-Yves Dupont
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Daniel Berry
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Arvina Ram
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Barry Scott
- The Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Murray P. Cox
- Statistics and Bioinformatics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
- The Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
- * E-mail:
| |
Collapse
|
124
|
Raineri S, Mellor J. IDH1: Linking Metabolism and Epigenetics. Front Genet 2018; 9:493. [PMID: 30405699 PMCID: PMC6206167 DOI: 10.3389/fgene.2018.00493] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/03/2018] [Indexed: 12/03/2022] Open
Abstract
Mutations in genes encoding enzymes of the tricarboxylic acid cycle often contribute to cancer development and progression by disrupting cell metabolism and altering the epigenetic landscape. This is exemplified by the isoforms of isocitrate dehydrogenase (IDH1/2), which metabolize isocitrate to α-Ketoglutarate (α-KG). Gain of function mutations in IDH1 or IDH2 result in reduced levels of α-KG as a result of increased formation of D-2-Hydroxyglutarate (2-HG). α-KG is an essential co-factor for certain histone and DNA demethylases, while 2-HG is a competitive inhibitor. These IDH1/2 mutations are thought to result in hypermethylated histones and DNA which in turn alters gene expression and drives cancer progression. While this model seems to be generally accepted in the field, the exact molecular mechanisms still remain elusive. How much of this model has been rigorously demonstrated and what is just being assumed? Are the effects genome-wide or focused on specific loci? This Perspective aims at elucidating the key questions that remain to be addressed, the experimental techniques that could be used to gain further insight into the molecular mechanisms involved and the additional consequences of these mutations beyond DNA and protein methylation.
Collapse
Affiliation(s)
- Silvia Raineri
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom.,Chronos Therapeutics, Oxford, United Kingdom
| | - Jane Mellor
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom.,Chronos Therapeutics, Oxford, United Kingdom
| |
Collapse
|
125
|
Kai Y, Andricovich J, Zeng Z, Zhu J, Tzatsos A, Peng W. Predicting CTCF-mediated chromatin interactions by integrating genomic and epigenomic features. Nat Commun 2018; 9:4221. [PMID: 30310060 PMCID: PMC6181989 DOI: 10.1038/s41467-018-06664-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 09/17/2018] [Indexed: 01/27/2023] Open
Abstract
The CCCTC-binding zinc-finger protein (CTCF)-mediated network of long-range chromatin interactions is important for genome organization and function. Although this network has been considered largely invariant, we find that it exhibits extensive cell-type-specific interactions that contribute to cell identity. Here, we present Lollipop, a machine-learning framework, which predicts CTCF-mediated long-range interactions using genomic and epigenomic features. Using ChIA-PET data as benchmark, we demonstrate that Lollipop accurately predicts CTCF-mediated chromatin interactions both within and across cell types, and outperforms other methods based only on CTCF motif orientation. Predictions are confirmed computationally and experimentally by Chromatin Conformation Capture (3C). Moreover, our approach identifies other determinants of CTCF-mediated chromatin wiring, such as gene expression within the loops. Our study contributes to a better understanding about the underlying principles of CTCF-mediated chromatin interactions and their impact on gene expression. CTCF mediates long-range chromatin interactions which are important for genome organization and function. Here, the authors demonstrate that CTCF-mediated interactome exhibits extensive plasticity and present Lollipop, a machine-learning framework which predicts CTCF-mediated long-range interactions using genomic and epigenomic features.
Collapse
Affiliation(s)
- Yan Kai
- Department of Physics, George Washington University (GWU), Washington, DC, 20052, USA.,Department of Anatomy and Cell Biology, Cancer Epigenetics Laboratory, GWU, Washington, DC, 20052, USA.,GWU Cancer Center, GWU School of Medicine and Health Sciences, Washington, DC, 20052, USA
| | - Jaclyn Andricovich
- Department of Anatomy and Cell Biology, Cancer Epigenetics Laboratory, GWU, Washington, DC, 20052, USA.,GWU Cancer Center, GWU School of Medicine and Health Sciences, Washington, DC, 20052, USA
| | - Zhouhao Zeng
- Department of Physics, George Washington University (GWU), Washington, DC, 20052, USA
| | - Jun Zhu
- Systems Biology Center, National Heart Lung and Blood Institute, National Institute of Health, Bethesda, MD, 20892, USA
| | - Alexandros Tzatsos
- Department of Anatomy and Cell Biology, Cancer Epigenetics Laboratory, GWU, Washington, DC, 20052, USA. .,GWU Cancer Center, GWU School of Medicine and Health Sciences, Washington, DC, 20052, USA.
| | - Weiqun Peng
- Department of Physics, George Washington University (GWU), Washington, DC, 20052, USA.
| |
Collapse
|
126
|
Brown JM, Roberts NA, Graham B, Waithe D, Lagerholm C, Telenius JM, De Ornellas S, Oudelaar AM, Scott C, Szczerbal I, Babbs C, Kassouf MT, Hughes JR, Higgs DR, Buckle VJ. A tissue-specific self-interacting chromatin domain forms independently of enhancer-promoter interactions. Nat Commun 2018; 9:3849. [PMID: 30242161 PMCID: PMC6155075 DOI: 10.1038/s41467-018-06248-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 08/24/2018] [Indexed: 11/08/2022] Open
Abstract
Self-interacting chromatin domains encompass genes and their cis-regulatory elements; however, the three-dimensional form a domain takes, whether this relies on enhancer-promoter interactions, and the processes necessary to mediate the formation and maintenance of such domains, remain unclear. To examine these questions, here we use a combination of high-resolution chromosome conformation capture, a non-denaturing form of fluorescence in situ hybridisation and super-resolution imaging to study a 70 kb domain encompassing the mouse α-globin regulatory locus. We show that this region forms an erythroid-specific, decompacted, self-interacting domain, delimited by frequently apposed CTCF/cohesin binding sites early in terminal erythroid differentiation, and does not require transcriptional elongation for maintenance of the domain structure. Formation of this domain does not rely on interactions between the α-globin genes and their major enhancers, suggesting a transcription-independent mechanism for establishment of the domain. However, absence of the major enhancers does alter internal domain interactions. Formation of a loop domain therefore appears to be a mechanistic process that occurs irrespective of the specific interactions within.
Collapse
Affiliation(s)
- Jill M Brown
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Nigel A Roberts
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Bryony Graham
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Dominic Waithe
- Wolfson Imaging Centre Oxford, MRC Weatherall Institute of Molecular Medicine, Oxford, OX3 9DS, UK
| | - Christoffer Lagerholm
- Wolfson Imaging Centre Oxford, MRC Weatherall Institute of Molecular Medicine, Oxford, OX3 9DS, UK
| | - Jelena M Telenius
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Sara De Ornellas
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - A Marieke Oudelaar
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Caroline Scott
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Izabela Szczerbal
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
- Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Wolynska 33, 60-637 Poznan, Poland
| | - Christian Babbs
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Mira T Kassouf
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Jim R Hughes
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Douglas R Higgs
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Veronica J Buckle
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK.
| |
Collapse
|
127
|
Tsujimura T, Takase O, Yoshikawa M, Sano E, Hayashi M, Takato T, Toyoda A, Okano H, Hishikawa K. Control of directionality of chromatin folding for the inter- and intra-domain contacts at the Tfap2c-Bmp7 locus. Epigenetics Chromatin 2018; 11:51. [PMID: 30213272 PMCID: PMC6137755 DOI: 10.1186/s13072-018-0221-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 08/27/2018] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Contact domains of chromatin serve as a fundamental unit to regulate action of enhancers for target genes. Looping between a pair of CCCTC-binding factor (CTCF)-binding sites in convergent orientations underlies the formation of contact domains, while those in divergent orientations establish domain boundaries. However, every CTCF site is not necessarily engaged in loop or boundary structures, leaving functions of CTCF in varied genomic contexts still elusive. The locus containing Tfap2c and Bmp7 encompasses two contact domains separated by a region between the two genes, termed transition zone (TZ), characterized by two arrays of CTCF sites in divergent configuration. In this study, we created deletion and inversion alleles of these and other regions across the locus and investigated how they impinge on the conformation. RESULTS Deletion of the whole two CTCF arrays with the CRISPR/Cas9 system resulted in impairment of blocking of chromatin contacts by the TZ, as assessed by the circular chromatin conformation capture assay (4C-seq). Deletion and inversion of either of the two arrays similarly, but less pronouncedly, led to reduction in the blocking activity. Thus, the divergent configuration provides the TZ with the strong boundary activity. Uniquely, we show the TZ harbors a 50-kb region within one of the two arrays that contacts broadly with the both flanking intervals, regardless of the presence or orientation of the other CTCF array. Further, we show the boundary CTCF array has little impact on intra-domain folding; instead, locally associating CTCF sites greatly affect it. CONCLUSIONS Our results show that the TZ not only separates the two domains, but also bears a wide interval that shows isotropic behavior of chromatin folding, indicating a potentially complex nature of actual boundaries in the genome. We also show that CTCF-binding sites inside a domain greatly contribute to the intra-domain folding of chromatin. Thus, the study reveals diverse and context-dependent roles of CTCF in organizing chromatin conformation at different levels.
Collapse
Affiliation(s)
- Taro Tsujimura
- Department of iPS Cell Research and Epigenetic Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
| | - Osamu Takase
- Department of iPS Cell Research and Epigenetic Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
| | - Masahiro Yoshikawa
- Department of iPS Cell Research and Epigenetic Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
| | - Etsuko Sano
- Department of iPS Cell Research and Epigenetic Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
| | - Matsuhiko Hayashi
- Apheresis and Dialysis Center, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
| | - Tsuyoshi Takato
- Department of Tissue Engineering, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 Japan
- Department of Oral-Maxillofacial Surgery and Orthodontics, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 Japan
| | - Atsushi Toyoda
- Center for Information Biology, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540 Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
| | - Keiichi Hishikawa
- Department of iPS Cell Research and Epigenetic Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan
| |
Collapse
|
128
|
Gambetta MC, Furlong EEM. The Insulator Protein CTCF Is Required for Correct Hox Gene Expression, but Not for Embryonic Development in Drosophila. Genetics 2018; 210:129-136. [PMID: 30021792 PMCID: PMC6116963 DOI: 10.1534/genetics.118.301350] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 07/12/2018] [Indexed: 02/07/2023] Open
Abstract
Insulator binding proteins (IBPs) play an important role in regulating gene expression by binding to specific DNA sites to facilitate appropriate gene regulation. There are several IBPs in Drosophila, each defined by their ability to insulate target gene promoters in transgenic assays from the activating or silencing effects of neighboring regulatory elements. Of these, only CCCTC-binding factor (CTCF) has an obvious ortholog in mammals. CTCF is essential for mammalian cell viability and is an important regulator of genome architecture. In flies, CTCF is both maternally deposited and zygotically expressed. Flies lacking zygotic CTCF die as young adults with homeotic defects, suggesting that specific Hox genes are misexpressed in inappropriate body segments. The lack of any major embryonic defects was assumed to be due to the maternal supply of CTCF protein, as maternally contributed factors are often sufficient to progress through much of embryogenesis. Here, we definitively determined the requirement of CTCF for developmental progression in Drosophila We generated animals that completely lack both maternal and zygotic CTCF and found that, contrary to expectation, these mutants progress through embryogenesis and larval life. They develop to pharate adults, which fail to eclose from their pupal case. These mutants show exacerbated homeotic defects compared to zygotic mutants, misexpressing the Hox gene Abdominal-B outside of its normal expression domain early in development. Our results indicate that loss of Drosophila CTCF is not accompanied by widespread effects on gene expression, which may be due to redundant functions with other IBPs. Rather, CTCF is required for correct Hox gene expression patterns and for the viability of adult Drosophila.
Collapse
Affiliation(s)
| | - Eileen E M Furlong
- European Molecular Biology Laboratory, Genome Biology Unit, 69117 Heidelberg, Germany
| |
Collapse
|
129
|
Peng Y, Zhang Y. Enhancer and super-enhancer: Positive regulators in gene transcription. Animal Model Exp Med 2018; 1:169-179. [PMID: 30891562 PMCID: PMC6388056 DOI: 10.1002/ame2.12032] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 07/19/2018] [Accepted: 07/31/2018] [Indexed: 12/23/2022] Open
Abstract
Enhancer is a positive regulator for spatiotemporal development in eukaryotes. As a cluster, super-enhancer is closely related to cell identity- and fate-determined processes. Both of them function tightly depending on their targeted transcription factors, cofactors, and genes through distal genomic interactions. They have been recognized as critical components and played positive roles in transcriptional regulatory network or factory. Recent advances of next-generation sequencing have dramatically expanded our ability and knowledge to interrogate the molecular mechanism of enhancer and super-enhancer for transcription. Here, we review the history, importance, advances and challenges on enhancer and super-enhancer field. This will benefit our understanding of their function mechanism for transcription underlying precise gene expression.
Collapse
Affiliation(s)
- Yanling Peng
- Animal Functional Genomics GroupAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenChina
| | - Yubo Zhang
- Animal Functional Genomics GroupAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenChina
| |
Collapse
|
130
|
Pavlaki I, Docquier F, Chernukhin I, Kita G, Gretton S, Clarkson CT, Teif VB, Klenova E. Poly(ADP-ribosyl)ation associated changes in CTCF-chromatin binding and gene expression in breast cells. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:718-730. [PMID: 29981477 PMCID: PMC6074063 DOI: 10.1016/j.bbagrm.2018.06.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 06/23/2018] [Accepted: 06/23/2018] [Indexed: 12/11/2022]
Abstract
CTCF is an evolutionarily conserved and ubiquitously expressed architectural protein regulating a plethora of cellular functions via different molecular mechanisms. CTCF can undergo a number of post-translational modifications which change its properties and functions. One such modifications linked to cancer is poly(ADP-ribosyl)ation (PARylation). The highly PARylated CTCF form has an apparent molecular mass of 180 kDa (referred to as CTCF180), which can be distinguished from hypo- and non-PARylated CTCF with the apparent molecular mass of 130 kDa (referred to as CTCF130). The existing data accumulated so far have been mainly related to CTCF130. However, the properties of CTCF180 are not well understood despite its abundance in a number of primary tissues. In this study we performed ChIP-seq and RNA-seq analyses in human breast cells 226LDM, which display predominantly CTCF130 when proliferating, but CTCF180 upon cell cycle arrest. We observed that in the arrested cells the majority of sites lost CTCF, whereas fewer sites gained CTCF or remain bound (i.e. common sites). The classical CTCF binding motif was found in the lost and common, but not in the gained sites. The changes in CTCF occupancies in the lost and common sites were associated with increased chromatin densities and altered expression from the neighboring genes. Based on these results we propose a model integrating the CTCF130/180 transition with CTCF-DNA binding and gene expression changes. This study also issues an important cautionary note concerning the design and interpretation of any experiments using cells and tissues where CTCF180 may be present.
Collapse
Affiliation(s)
- Ioanna Pavlaki
- University of Essex, School of Biological Sciences, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK
| | - France Docquier
- University of Essex, School of Biological Sciences, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK
| | - Igor Chernukhin
- University of Essex, School of Biological Sciences, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK
| | - Georgia Kita
- University of Essex, School of Biological Sciences, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK
| | - Svetlana Gretton
- University of Essex, School of Biological Sciences, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK
| | - Christopher T Clarkson
- University of Essex, School of Biological Sciences, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK
| | - Vladimir B Teif
- University of Essex, School of Biological Sciences, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK.
| | - Elena Klenova
- University of Essex, School of Biological Sciences, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK.
| |
Collapse
|
131
|
Cuartero S, Merkenschlager M. Three-dimensional genome organization in normal and malignant haematopoiesis. Curr Opin Hematol 2018; 25:323-328. [PMID: 29702522 DOI: 10.1097/moh.0000000000000436] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW The three-dimensional organization of the genome inside the nucleus impacts on key aspects of genome function, including transcription, DNA replication and repair. The chromosome maintenance complex cohesin and the DNA binding protein CTCF cooperate to drive the formation of self-interacting topological domains. This facilitates transcriptional regulation via enhancer-promoter interactions, controls the distribution and release of torsional strain, and affects the frequency with which particular translocations arise, based on the spatial proximity of translocation partners. Here we discuss recent insights into the mechanisms of three-dimensional genome organization, their relationship to haematopoietic differentiation and malignant transformation. RECENT FINDINGS Cohesin mutations are frequently found in myeloid malignancies. Significantly, cohesin mutations can drive increased self-renewal of haematopoietic stem and progenitor cells, which may facilitate the accumulation of genetic lesions and leukaemic transformation. It is therefore important to elucidate the mechanisms that link cohesin to pathways that regulate the balance between self-renewal and differentiation. Chromosomal translocations are key to lymphoid malignancies, and recent findings link three-dimensional genome organization to the frequency and the genomic position of DNA double strand breaks. SUMMARY Three-dimensional genome organization can help explain genome function in normal and malignant haematopoiesis.
Collapse
Affiliation(s)
- Sergi Cuartero
- Lymphocyte Development Group, Epigenetics Section, MRC London Institute of Medical Sciences, Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
| | | |
Collapse
|
132
|
Distinct macrophage populations direct inflammatory versus physiological changes in adipose tissue. Proc Natl Acad Sci U S A 2018; 115:E5096-E5105. [PMID: 29760084 DOI: 10.1073/pnas.1802611115] [Citation(s) in RCA: 255] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Obesity is characterized by an accumulation of macrophages in adipose, some of which form distinct crown-like structures (CLS) around fat cells. While multiple discrete adipose tissue macrophage (ATM) subsets are thought to exist, their respective effects on adipose tissue, and the transcriptional mechanisms that underlie the functional differences between ATM subsets, are not well understood. We report that obese fat tissue of mice and humans contain multiple distinct populations of ATMs with unique tissue distributions, transcriptomes, chromatin landscapes, and functions. Mouse Ly6c ATMs reside outside of CLS and are adipogenic, while CD9 ATMs reside within CLS, are lipid-laden, and are proinflammatory. Adoptive transfer of Ly6c ATMs into lean mice activates gene programs typical of normal adipocyte physiology. By contrast, adoptive transfer of CD9 ATMs drives gene expression that is characteristic of obesity. Importantly, human adipose tissue contains similar ATM populations, including lipid-laden CD9 ATMs that increase with body mass. These results provide a higher resolution of the cellular and functional heterogeneity within ATMs and provide a framework within which to develop new immune-directed therapies for the treatment of obesity and related sequela.
Collapse
|
133
|
Matthews BJ, Waxman DJ. Computational prediction of CTCF/cohesin-based intra-TAD loops that insulate chromatin contacts and gene expression in mouse liver. eLife 2018; 7:e34077. [PMID: 29757144 PMCID: PMC5986275 DOI: 10.7554/elife.34077] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 04/30/2018] [Indexed: 12/18/2022] Open
Abstract
CTCF and cohesin are key drivers of 3D-nuclear organization, anchoring the megabase-scale Topologically Associating Domains (TADs) that segment the genome. Here, we present and validate a computational method to predict cohesin-and-CTCF binding sites that form intra-TAD DNA loops. The intra-TAD loop anchors identified are structurally indistinguishable from TAD anchors regarding binding partners, sequence conservation, and resistance to cohesin knockdown; further, the intra-TAD loops retain key functional features of TADs, including chromatin contact insulation, blockage of repressive histone mark spread, and ubiquity across tissues. We propose that intra-TAD loops form by the same loop extrusion mechanism as the larger TAD loops, and that their shorter length enables finer regulatory control in restricting enhancer-promoter interactions, which enables selective, high-level expression of gene targets of super-enhancers and genes located within repressive nuclear compartments. These findings elucidate the role of intra-TAD cohesin-and-CTCF binding in nuclear organization associated with widespread insulation of distal enhancer activity.
Collapse
Affiliation(s)
- Bryan J Matthews
- Department of Biology and Bioinformatics ProgramBoston UniversityBostonUnited States
| | - David J Waxman
- Department of Biology and Bioinformatics ProgramBoston UniversityBostonUnited States
| |
Collapse
|
134
|
Sun L, Yu R, Dang W. Chromatin Architectural Changes during Cellular Senescence and Aging. Genes (Basel) 2018; 9:genes9040211. [PMID: 29659513 PMCID: PMC5924553 DOI: 10.3390/genes9040211] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/02/2018] [Accepted: 04/12/2018] [Indexed: 12/21/2022] Open
Abstract
Chromatin 3D structure is highly dynamic and associated with many biological processes, such as cell cycle progression, cellular differentiation, cell fate reprogramming, cancer development, cellular senescence, and aging. Recently, by using chromosome conformation capture technologies, tremendous findings have been reported about the dynamics of genome architecture, their associated proteins, and the underlying mechanisms involved in regulating chromatin spatial organization and gene expression. Cellular senescence and aging, which involve multiple cellular and molecular functional declines, also undergo significant chromatin structural changes, including alternations of heterochromatin and disruption of higher-order chromatin structure. In this review, we summarize recent findings related to genome architecture, factors regulating chromatin spatial organization, and how they change during cellular senescence and aging.
Collapse
Affiliation(s)
- Luyang Sun
- Huffington Center on Aging, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Ruofan Yu
- Huffington Center on Aging, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Weiwei Dang
- Huffington Center on Aging, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
| |
Collapse
|
135
|
Razin SV, Gavrilov AA. Structural–Functional Domains of the Eukaryotic Genome. BIOCHEMISTRY (MOSCOW) 2018; 83:302-312. [DOI: 10.1134/s0006297918040028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/27/2017] [Indexed: 08/30/2023]
|
136
|
CRISPR-based strategies for studying regulatory elements and chromatin structure in mammalian gene control. Mamm Genome 2018; 29:205-228. [PMID: 29196861 PMCID: PMC9881389 DOI: 10.1007/s00335-017-9727-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 11/27/2017] [Indexed: 01/31/2023]
Abstract
The development of high-throughput methods has enabled the genome-wide identification of putative regulatory elements in a wide variety of mammalian cells at an unprecedented resolution. Extensive genomic studies have revealed the important role of regulatory elements and genetic variation therein in disease formation and risk. In most cases, there is only correlative evidence for the roles of these elements and non-coding changes within these elements in pathogenesis. With the advent of genome- and epigenome-editing tools based on the CRISPR technology, it is now possible to test the functional relevance of the regulatory elements and alterations on a genomic scale. Here, we review the various CRISPR-based strategies that have been developed to functionally validate the candidate regulatory elements in mammals as well as the non-coding genetic variants found to be associated with human disease. We also discuss how these synthetic biology tools have helped to elucidate the role of three-dimensional nuclear architecture and higher-order chromatin organization in shaping functional genome and controlling gene expression.
Collapse
|
137
|
Arzate-Mejía RG, Recillas-Targa F, Corces VG. Developing in 3D: the role of CTCF in cell differentiation. Development 2018; 145:dev137729. [PMID: 29567640 PMCID: PMC5897592 DOI: 10.1242/dev.137729] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
CTCF is a highly conserved zinc-finger DNA-binding protein that mediates interactions between distant sequences in the genome. As a consequence, CTCF regulates enhancer-promoter interactions and contributes to the three-dimensional organization of the genome. Recent studies indicate that CTCF is developmentally regulated, suggesting that it plays a role in cell type-specific genome organization. Here, we review these studies and discuss how CTCF functions during the development of various cell and tissue types, ranging from embryonic stem cells and gametes, to neural, muscle and cardiac cells. We propose that the lineage-specific control of CTCF levels, and its partnership with lineage-specific transcription factors, allows for the control of cell type-specific gene expression via chromatin looping.
Collapse
Affiliation(s)
- Rodrigo G Arzate-Mejía
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 Ciudad de México, México
| | - Félix Recillas-Targa
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 Ciudad de México, México
| | - Victor G Corces
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| |
Collapse
|
138
|
Winick-Ng W, Rylett RJ. Into the Fourth Dimension: Dysregulation of Genome Architecture in Aging and Alzheimer's Disease. Front Mol Neurosci 2018. [PMID: 29541020 PMCID: PMC5835833 DOI: 10.3389/fnmol.2018.00060] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by synapse dysfunction and cognitive impairment. Understanding the development and progression of AD is challenging, as the disease is highly complex and multifactorial. Both environmental and genetic factors play a role in AD pathogenesis, highlighted by observations of complex DNA modifications at the single gene level, and by new evidence that also implicates changes in genome architecture in AD patients. The four-dimensional structure of chromatin in space and time is essential for context-dependent regulation of gene expression in post-mitotic neurons. Dysregulation of epigenetic processes have been observed in the aging brain and in patients with AD, though there is not yet agreement on the impact of these changes on transcription. New evidence shows that proteins involved in genome organization have altered expression and localization in the AD brain, suggesting that the genomic landscape may play a critical role in the development of AD. This review discusses the role of the chromatin organizers and epigenetic modifiers in post-mitotic cells, the aging brain, and in the development and progression of AD. How these new insights can be used to help determine disease risk and inform treatment strategies will also be discussed.
Collapse
Affiliation(s)
- Warren Winick-Ng
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.,Molecular Medicine Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada
| | - R Jane Rylett
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.,Molecular Medicine Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada
| |
Collapse
|
139
|
Catarino RR, Stark A. Assessing sufficiency and necessity of enhancer activities for gene expression and the mechanisms of transcription activation. Genes Dev 2018; 32:202-223. [PMID: 29491135 PMCID: PMC5859963 DOI: 10.1101/gad.310367.117] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Enhancers are important genomic regulatory elements directing cell type-specific transcription. They assume a key role during development and disease, and their identification and functional characterization have long been the focus of scientific interest. The advent of next-generation sequencing and clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9-based genome editing has revolutionized the means by which we study enhancer biology. In this review, we cover recent developments in the prediction of enhancers based on chromatin characteristics and their identification by functional reporter assays and endogenous DNA perturbations. We discuss that the two latter approaches provide different and complementary insights, especially in assessing enhancer sufficiency and necessity for transcription activation. Furthermore, we discuss recent insights into mechanistic aspects of enhancer function, including findings about cofactor requirements and the role of post-translational histone modifications such as monomethylation of histone H3 Lys4 (H3K4me1). Finally, we survey how these approaches advance our understanding of transcription regulation with respect to promoter specificity and transcriptional bursting and provide an outlook covering open questions and promising developments.
Collapse
Affiliation(s)
- Rui R Catarino
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Alexander Stark
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| |
Collapse
|
140
|
Oudelaar AM, Davies JOJ, Downes DJ, Higgs DR, Hughes JR. Robust detection of chromosomal interactions from small numbers of cells using low-input Capture-C. Nucleic Acids Res 2018; 45:e184. [PMID: 29186505 PMCID: PMC5728395 DOI: 10.1093/nar/gkx1194] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/21/2017] [Indexed: 02/06/2023] Open
Abstract
Chromosome conformation capture (3C) techniques are crucial to understanding tissue-specific regulation of gene expression, but current methods generally require large numbers of cells. This hampers the investigation of chromatin architecture in rare cell populations. We present a new low-input Capture-C approach that can generate high-quality 3C interaction profiles from 10 000-20 000 cells, depending on the resolution used for analysis. We also present a PCR-free, sequencing-free 3C technique based on NanoString technology called C-String. By comparing C-String and Capture-C interaction profiles we show that the latter are not skewed by PCR amplification. Furthermore, we demonstrate that chromatin interactions detected by Capture-C do not depend on the degree of cross-linking by performing experiments with varying formaldehyde concentrations.
Collapse
Affiliation(s)
- A Marieke Oudelaar
- Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - James O J Davies
- Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Damien J Downes
- Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Douglas R Higgs
- Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Jim R Hughes
- Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| |
Collapse
|
141
|
Hsu SC, Blobel GA. The Role of Bromodomain and Extraterminal Motif (BET) Proteins in Chromatin Structure. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2017; 82:37-43. [PMID: 29196562 DOI: 10.1101/sqb.2017.82.033829] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Bromodomain and extraterminal motif (BET) proteins have been widely investigated for their roles in gene regulation and their potential as therapeutic targets in cancer. Pharmacologic BET inhibitors target the conserved bromodomain-acetyllysine interaction and do not distinguish between BRD2, BRD3, and BRD4. Thus, comparatively little is known regarding the distinct roles played by individual family members, as well as the underlying mechanisms that drive the transcriptional effects of BET inhibitors. Here we review studies regarding the contributions of BET proteins to genome structure and function, including recent work identifying a role for BRD2 as a component of functional and physical chromatin domain boundaries. We also discuss directions of future studies aimed at providing insights into broader architectural functions of BET proteins and their roles in chromatin domain boundary formation.
Collapse
Affiliation(s)
- Sarah C Hsu
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Gerd A Blobel
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
| |
Collapse
|
142
|
Fontanals-Cirera B, Hasson D, Vardabasso C, Di Micco R, Agrawal P, Chowdhury A, Gantz M, de Pablos-Aragoneses A, Morgenstern A, Wu P, Filipescu D, Valle-Garcia D, Darvishian F, Roe JS, Davies MA, Vakoc CR, Hernando E, Bernstein E. Harnessing BET Inhibitor Sensitivity Reveals AMIGO2 as a Melanoma Survival Gene. Mol Cell 2017; 68:731-744.e9. [PMID: 29149598 PMCID: PMC5993436 DOI: 10.1016/j.molcel.2017.11.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 08/18/2017] [Accepted: 11/01/2017] [Indexed: 01/13/2023]
Abstract
Bromodomain and extraterminal domain inhibitors (BETi) represent promising therapeutic agents for metastatic melanoma, yet their mechanism of action remains unclear. Here we interrogated the transcriptional effects of BETi and identified AMIGO2, a transmembrane molecule, as a BET target gene essential for melanoma cell survival. AMIGO2 is upregulated in melanoma cells and tissues compared to human melanocytes and nevi, and AMIGO2 silencing in melanoma cells induces G1/S arrest followed by apoptosis. We identified the pseudokinase PTK7 as an AMIGO2 interactor whose function is regulated by AMIGO2. Epigenomic profiling and genome editing revealed that AMIGO2 is regulated by a melanoma-specific BRD2/4-bound promoter and super-enhancer configuration. Upon BETi treatment, BETs are evicted from these regulatory elements, resulting in AMIGO2 silencing and changes in PTK7 proteolytic processing. Collectively, this study uncovers mechanisms underlying the therapeutic effects of BETi in melanoma and reveals the AMIGO2-PTK7 axis as a targetable pathway for metastatic melanoma.
Collapse
Affiliation(s)
- Barbara Fontanals-Cirera
- Department of Pathology and Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical Center, New York, NY, USA
| | - Dan Hasson
- Departments of Oncological Sciences and Dermatology, 1470 Madison Avenue, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Chiara Vardabasso
- Departments of Oncological Sciences and Dermatology, 1470 Madison Avenue, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Raffaella Di Micco
- Department of Pathology and Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical Center, New York, NY, USA
| | - Praveen Agrawal
- Department of Pathology and Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical Center, New York, NY, USA
| | - Asif Chowdhury
- Departments of Oncological Sciences and Dermatology, 1470 Madison Avenue, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Madeleine Gantz
- Departments of Oncological Sciences and Dermatology, 1470 Madison Avenue, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ana de Pablos-Aragoneses
- Department of Pathology and Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical Center, New York, NY, USA
| | - Ari Morgenstern
- Department of Pathology and Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical Center, New York, NY, USA
| | - Pamela Wu
- Institute of Systems Genetics, New York University Langone Medical Center, New York, NY, USA
| | - Dan Filipescu
- Departments of Oncological Sciences and Dermatology, 1470 Madison Avenue, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - David Valle-Garcia
- Departments of Oncological Sciences and Dermatology, 1470 Madison Avenue, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Farbod Darvishian
- Department of Pathology and Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical Center, New York, NY, USA
| | - Jae-Seok Roe
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, USA
| | - Michael A Davies
- Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Eva Hernando
- Department of Pathology and Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical Center, New York, NY, USA.
| | - Emily Bernstein
- Departments of Oncological Sciences and Dermatology, 1470 Madison Avenue, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| |
Collapse
|
143
|
Abstract
CCCTC-binding factor (CTCF) sites are enriched at the boundaries of topologically associated domains (TADs), but their function within TADs is unclear. Removal of sub-TAD CTCF sites adjacent to the α-globin enhancers is now shown to result in inappropriate activation of neighbouring genes. Intra-TAD enhancer insulation might be broadly important for tissue specificity of enhancers.
Collapse
Affiliation(s)
- Ivan Krivega
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Ann Dean
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| |
Collapse
|
144
|
Oudelaar AM, Hanssen LL, Hardison RC, Kassouf MT, Hughes JR, Higgs DR. Between form and function: the complexity of genome folding. Hum Mol Genet 2017; 26:R208-R215. [PMID: 28977451 PMCID: PMC5886466 DOI: 10.1093/hmg/ddx306] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 07/18/2017] [Accepted: 07/19/2017] [Indexed: 01/24/2023] Open
Abstract
It has been known for over a century that chromatin is not randomly distributed within the nucleus. However, the question of how DNA is folded and the influence of such folding on nuclear processes remain topics of intensive current research. A longstanding, unanswered question is whether nuclear organization is simply a reflection of nuclear processes such as transcription and replication, or whether chromatin is folded by independent mechanisms and this per se encodes function? Evidence is emerging that both may be true. Here, using the α-globin gene cluster as an illustrative model, we provide an overview of the most recent insights into the layers of genome organization across different scales and how this relates to gene activity.
Collapse
Affiliation(s)
- A. Marieke Oudelaar
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS, UK
| | - Lars L.P. Hanssen
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS, UK
| | - Ross C. Hardison
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Mira T. Kassouf
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS, UK
| | - Jim R. Hughes
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS, UK
| | - Douglas R. Higgs
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS, UK
| |
Collapse
|