1
|
Fletcher A, Zhao R, Enciso G. Non-cooperative mechanism for bounded and ultrasensitive chromatin remodeling. J Theor Biol 2022; 534:110946. [PMID: 34717936 DOI: 10.1016/j.jtbi.2021.110946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 10/19/2021] [Accepted: 10/22/2021] [Indexed: 11/18/2022]
Abstract
Chromatin remodeling is an essential form of gene regulation that is involved in a variety of biological processes. We develop a theoretical model that takes advantage of percolation effects at the level of nucleosome interactions, which allows for ultrasensitive chromatin expansion. This model is non-cooperative and readily provides spatial bounds to the expansion region, preventing uncontrolled remodeling events. We explore different chromatin architectures and the ultrasensitivity of the chromatin density as a function of transcription factor concentration. We also compare our model with experimental data involving an inhibitor of nucleosome acetylation. These results suggest a novel mechanism for spatially-bounded chromatin remodeling and they provide means for quantitative comparisons between proposed models of chromatin architecture.
Collapse
Affiliation(s)
- Alvaro Fletcher
- Mathematical, Computational, and Systems Biology program, University of California, Irvine, Irvine, CA, USA
| | - Ruonan Zhao
- Department of Mathematics, University of California, Irvine, Irvine, CA, USA
| | - German Enciso
- Department of Mathematics, University of California, Irvine, Irvine, CA, USA.
| |
Collapse
|
2
|
Kalashnikova DA, Maksimov DA, Romanov SE, Laktionov PP, Koryakov DE. SetDB1 and Su(var)3-9 play non-overlapping roles in somatic cell chromosomes of Drosophila melanogaster. J Cell Sci 2021; 134:jcs.253096. [PMID: 33288549 DOI: 10.1242/jcs.253096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/30/2020] [Indexed: 11/20/2022] Open
Abstract
We explored functional roles of two H3K9-specific histone methyltransferases of Drosophila melanogaster, SetDB1 (also known as Eggless) and Su(var)3-9. Using the DamID approach, we generated the binding profile for SetDB1 in Drosophila salivary gland chromosomes, and matched it to the profile of Su(var)3-9. Unlike Su(var)3-9, SetDB1 turned out to be an euchromatic protein that is absent from repeated DNA compartments, and is largely restricted to transcription start sites (TSSs) and 5' untranslated regions (5'UTRs) of ubiquitously expressed genes. Significant SetDB1 association is also observed at binding sites for the insulator protein CP190. SetDB1 and H3K9 di- and tri-methylated (me2 and me3)-enriched sites tend to display poor overlap. At the same time, SetDB1 has a clear connection with the distribution of H3K27me3 mark. SetDB1 binds outside the domains possessing this modification, and about half of the borders of H3K27me3 domains are decorated by SetDB1 together with actively transcribed genes. On the basis of poor correlation between the distribution of SetDB1 and H3K9 methylation marks, we speculate that, in somatic cells, SetDB1 may contribute to the methylation of a broader set of chromosomal proteins than just H3K9. In addition, SetDB1 can be expected to play a role in the establishment of chromatin functional domains.
Collapse
Affiliation(s)
| | - Daniil A Maksimov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia
| | - Stanislav E Romanov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia.,Laboratory of Epigenetics, Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Petr P Laktionov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia.,Laboratory of Epigenetics, Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Dmitry E Koryakov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia
| |
Collapse
|
3
|
Penagos-Puig A, Furlan-Magaril M. Heterochromatin as an Important Driver of Genome Organization. Front Cell Dev Biol 2020; 8:579137. [PMID: 33072761 PMCID: PMC7530337 DOI: 10.3389/fcell.2020.579137] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/31/2020] [Indexed: 12/14/2022] Open
Abstract
Heterochromatin is a constituent of eukaryotic genomes with functions spanning from gene expression silencing to constraining DNA replication and repair. Inside the nucleus, heterochromatin segregates spatially from euchromatin and is localized preferentially toward the nuclear periphery and surrounding the nucleolus. Despite being an abundant nuclear compartment, little is known about how heterochromatin regulates and participates in the mechanisms driving genome organization. Here, we review pioneer and recent evidence that explores the functional role of heterochromatin in the formation of distinct chromatin compartments and how failure of the molecular mechanisms forming heterochromatin leads to disarray of genome conformation and disease.
Collapse
Affiliation(s)
- Andrés Penagos-Puig
- Department of Molecular Genetics, Institute of Cellular Physiology, National Autonomous University of Mexico, Mexico City, Mexico
| | - Mayra Furlan-Magaril
- Department of Molecular Genetics, Institute of Cellular Physiology, National Autonomous University of Mexico, Mexico City, Mexico
| |
Collapse
|
4
|
Teo YV, Capri M, Morsiani C, Pizza G, Faria AMC, Franceschi C, Neretti N. Cell-free DNA as a biomarker of aging. Aging Cell 2019; 18:e12890. [PMID: 30575273 PMCID: PMC6351822 DOI: 10.1111/acel.12890] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 10/12/2018] [Accepted: 11/10/2018] [Indexed: 12/18/2022] Open
Abstract
Cell-free DNA (cfDNA) is present in the circulating plasma and other body fluids and is known to originate mainly from apoptotic cells. Here, we provide the first in vivo evidence of global and local chromatin changes in human aging by analyzing cfDNA from the blood of individuals of different age groups. Our results show that nucleosome signals inferred from cfDNA are consistent with the redistribution of heterochromatin observed in cellular senescence and aging in other model systems. In addition, we detected a relative cfDNA loss at several genomic locations, such as transcription start and termination sites, 5'UTR of L1HS retrotransposons and dimeric AluY elements with age. Our results also revealed age and deteriorating health status correlate with increased enrichment of signals from cells in different tissues. In conclusion, our results show that the sequencing of circulating cfDNA from human blood plasma can be used as a noninvasive methodology to study age-associated changes to the epigenome in vivo.
Collapse
Affiliation(s)
- Yee Voan Teo
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island
| | - Miriam Capri
- CIG Interdepartmental Centre "Galvani", University of Bologna, Bologna, Italy
- DIMES-Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Cristina Morsiani
- DIMES-Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Grazia Pizza
- DIMES-Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology & Metabolism, Department of Medicine, Imperial College London, London, UK
| | - Ana Maria Caetano Faria
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Nicola Neretti
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island
| |
Collapse
|
5
|
Li M, Ma Z, Roy S, Patel SK, Lane DC, Duffy CR, Cai HN. Selective interactions between diverse STEs organize the ANT-C Hox cluster. Sci Rep 2018; 8:15158. [PMID: 30310129 PMCID: PMC6181975 DOI: 10.1038/s41598-018-33588-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 10/01/2018] [Indexed: 11/09/2022] Open
Abstract
The three-dimensional organization of the eukaryotic genome is important for its structure and function. Recent studies indicate that hierarchies of chromatin loops underlie important aspects of both genomic organization and gene regulation. Looping between insulator or boundary elements interferes with enhancer-promoter communications and limits the spread active or repressive organized chromatin. We have used the SF1 insulator in the Drosophila Antennapedia homeotic gene complex (ANT-C) as a model to study the mechanism and regulation of chromatin looping events. We reported previously that SF1 tethers a transient chromatin loop in the early embryo that insulates the Hox gene Sex comb reduce from the neighbor non-Hox gene fushi tarazu for their independent regulation. To further probe the functional range and connectivity of SF1, we used high-resolution chromosomal conformation capture (3C) to search for SF1 looping partners across ANT-C. We report here the identification of three distal SF1 Tether Elements (STEs) located in the labial, Deformed and Antennapedia Hox gene regions, extending the range of SF1 looping network to the entire complex. These novel STEs are bound by four different combinations of insulator proteins and exhibit distinct behaviors in enhancer block, enhancer-bypass and boundary functions. Significantly, the six STEs we identified so far map to all but one of the major boundaries between repressive and active histone domains, underlining the functional relevance of these long-range chromatin loops in organizing the Hox complex. Importantly, SF1 selectively captured with only 5 STEs out of ~20 sites that display similar insulator binding profiles, indicating that presence of insulator proteins alone is not sufficient to determine looping events. These findings suggest that selective interaction among diverse STE insulators organize the Drosophila Hox genes in the 3D nuclear space.
Collapse
Affiliation(s)
- Mo Li
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Zhibo Ma
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Sharmila Roy
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Sapna K Patel
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Derrick C Lane
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Carly R Duffy
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Haini N Cai
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA.
| |
Collapse
|
6
|
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
|
7
|
Laczik M, Hendrickx J, Veillard AC, Tammoh M, Marzi S, Poncelet D. Iterative Fragmentation Improves the Detection of ChIP-seq Peaks for Inactive Histone Marks. Bioinform Biol Insights 2016; 10:209-224. [PMID: 27812282 PMCID: PMC5081244 DOI: 10.4137/bbi.s40628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 08/23/2016] [Accepted: 08/28/2016] [Indexed: 01/18/2023] Open
Abstract
As chromatin immunoprecipitation (ChIP) sequencing is becoming the dominant technique for studying chromatin modifications, new protocols surface to improve the method. Bioinformatics is also essential to analyze and understand the results, and precise analysis helps us to identify the effects of protocol optimizations. We applied iterative sonication – sending the fragmented DNA after ChIP through additional round(s) of shearing – to a number of samples, testing the effects on different histone marks, aiming to uncover potential benefits of inactive histone marks specifically. We developed an analysis pipeline that utilizes our unique, enrichment-type specific approach to peak calling. With the help of this pipeline, we managed to accurately describe the advantages and disadvantages of the iterative refragmentation technique, and we successfully identified possible fields for its applications, where it enhances the results greatly. In addition to the resonication protocol description, we provide guidelines for peak calling optimization and a freely implementable pipeline for data analysis.
Collapse
Affiliation(s)
- Miklós Laczik
- Doctorate Student, Doctoral College of Agronomy and Bioengineering, Gembloux Agro-Biotech, University of Liège, Liège, Belgium.; Researcher, R&D Epigenetics Department of Diagenode SA, Liège, Belgium
| | - Jan Hendrickx
- Researcher, R&D Epigenetics Department of Diagenode SA, Liège, Belgium
| | | | - Mustafa Tammoh
- Researcher, R&D Epigenetics Department of Diagenode SA, Liège, Belgium
| | - Sarah Marzi
- Doctorate Student, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | | |
Collapse
|
8
|
Diermeier S, Kolovos P, Heizinger L, Schwartz U, Georgomanolis T, Zirkel A, Wedemann G, Grosveld F, Knoch TA, Merkl R, Cook PR, Längst G, Papantonis A. TNFα signalling primes chromatin for NF-κB binding and induces rapid and widespread nucleosome repositioning. Genome Biol 2014; 15:536. [PMID: 25608606 PMCID: PMC4268828 DOI: 10.1186/s13059-014-0536-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 11/07/2014] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The rearrangement of nucleosomes along the DNA fiber profoundly affects gene expression, but little is known about how signalling reshapes the chromatin landscape, in three-dimensional space and over time, to allow establishment of new transcriptional programs. RESULTS Using micrococcal nuclease treatment and high-throughput sequencing, we map genome-wide changes in nucleosome positioning in primary human endothelial cells stimulated with tumour necrosis factor alpha (TNFα) - a proinflammatory cytokine that signals through nuclear factor kappa-B (NF-κB). Within 10 min, nucleosomes reposition at regions both proximal and distal to NF-κB binding sites, before the transcription factor quantitatively binds thereon. Similarly, in long TNFα-responsive genes, repositioning precedes transcription by pioneering elongating polymerases and appears to nucleate from intragenic enhancer clusters resembling super-enhancers. By 30 min, widespread repositioning throughout megabase pair-long chromosomal segments, with consequential effects on three-dimensional structure (detected using chromosome conformation capture), is seen. CONCLUSIONS Whilst nucleosome repositioning is viewed as a local phenomenon, our results point to effects occurring over multiple scales. Here, we present data in support of a TNFα-induced priming mechanism, mostly independent of NF-κB binding and/or elongating RNA polymerases, leading to a plastic network of interactions that affects DNA accessibility over large domains.
Collapse
Affiliation(s)
- Sarah Diermeier
- />Department of Biochemistry III, University of Regensburg, Universität Strasse 31, 93053 Regensburg, Germany
- />Present address: Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, 11724 NY USA
| | - Petros Kolovos
- />Cell Biology and Genetics, Erasmus Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
- />Biophysical Genomics, Erasmus Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Leonhard Heizinger
- />Institute of Biophysics and Physical Biochemistry, University of Regensburg, 93040 Regensburg, Germany
| | - Uwe Schwartz
- />Department of Biochemistry III, University of Regensburg, Universität Strasse 31, 93053 Regensburg, Germany
| | - Theodore Georgomanolis
- />Centre for Molecular Medicine, University of Cologne, Robert-Koch-Strasse 21, 50931 Cologne, Germany
| | - Anne Zirkel
- />Centre for Molecular Medicine, University of Cologne, Robert-Koch-Strasse 21, 50931 Cologne, Germany
| | - Gero Wedemann
- />Institute for Applied Computer Science, University of Applied Sciences Stralsund, Zur Schwedenschanze 15, 18435 Stralsund, Germany
| | - Frank Grosveld
- />Cell Biology and Genetics, Erasmus Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Tobias A Knoch
- />Biophysical Genomics, Erasmus Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
- />BioQuant & German Cancer Research Center, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany
| | - Rainer Merkl
- />Institute of Biophysics and Physical Biochemistry, University of Regensburg, 93040 Regensburg, Germany
| | - Peter R Cook
- />Sir William Dunn School of Pathology, University of Oxford, South Parks Road, OX1 3RE Oxford, United Kingdom
| | - Gernot Längst
- />Department of Biochemistry III, University of Regensburg, Universität Strasse 31, 93053 Regensburg, Germany
| | - Argyris Papantonis
- />Centre for Molecular Medicine, University of Cologne, Robert-Koch-Strasse 21, 50931 Cologne, Germany
- />Sir William Dunn School of Pathology, University of Oxford, South Parks Road, OX1 3RE Oxford, United Kingdom
| |
Collapse
|
9
|
Medusa: a novel gene drive system for confined suppression of insect populations. PLoS One 2014; 9:e102694. [PMID: 25054803 PMCID: PMC4108329 DOI: 10.1371/journal.pone.0102694] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Accepted: 06/23/2014] [Indexed: 01/03/2023] Open
Abstract
Gene drive systems provide novel opportunities for insect population suppression by driving genes that confer a fitness cost into pest or disease vector populations; however regulatory issues arise when genes are capable of spreading across international borders. Gene drive systems displaying threshold properties provide a solution since they can be confined to local populations and eliminated through dilution with wild-types. We propose a novel, threshold-dependent gene drive system, Medusa, capable of inducing a local and reversible population crash. Medusa consists of four components - two on the X chromosome, and two on the Y chromosome. A maternally-expressed, X-linked toxin and a zygotically-expressed, Y-linked antidote results in suppression of the female population and selection for the presence of the transgene-bearing Y because only male offspring of Medusa-bearing females are protected from the effects of the toxin. At the same time, the combination of a zygotically-expressed, Y-linked toxin and a zygotically-expressed, X-linked antidote selects for the transgene-bearing X in the presence of the transgene-bearing Y. Together these chromosomes create a balanced lethal system that spreads while selecting against females when present above a certain threshold frequency. Simple population dynamic models show that an all-male release of Medusa males, carried out over six generations, is expected to induce a population crash within 12 generations for modest release sizes on the order of the wild population size. Re-invasion of non-transgenic insects into a suppressed population can result in a population rebound; however this can be prevented through regular releases of modest numbers of Medusa males. Finally, we outline how Medusa could be engineered with currently available molecular tools.
Collapse
|
10
|
Heger P, Wiehe T. New tools in the box: An evolutionary synopsis of chromatin insulators. Trends Genet 2014; 30:161-71. [DOI: 10.1016/j.tig.2014.03.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/24/2014] [Accepted: 03/25/2014] [Indexed: 01/19/2023]
|
11
|
Orsi GA, Kasinathan S, Hughes KT, Saminadin-Peter S, Henikoff S, Ahmad K. High-resolution mapping defines the cooperative architecture of Polycomb response elements. Genome Res 2014; 24:809-20. [PMID: 24668908 PMCID: PMC4009610 DOI: 10.1101/gr.163642.113] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Polycomb-mediated chromatin repression modulates gene expression during development in metazoans. Binding of multiple sequence-specific factors at discrete Polycomb response elements (PREs) is thought to recruit repressive complexes that spread across an extended chromatin domain. To dissect the structure of PREs, we applied high-resolution mapping of nonhistone chromatin proteins in native chromatin of Drosophila cells. Analysis of occupied sites reveal interactions between transcription factors that stabilize Polycomb anchoring to DNA, and implicate the general transcription factor ADF1 as a novel PRE component. By comparing two Drosophila cell lines with differential chromatin states, we provide evidence that repression is accomplished by enhanced Polycomb recruitment both to PREs and to target promoters of repressed genes. These results suggest that the stability of multifactor complexes at promoters and regulatory elements is a crucial aspect of developmentally regulated gene expression.
Collapse
Affiliation(s)
- Guillermo A Orsi
- Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | | | | | | | | |
Collapse
|