1
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Son JB, Kim S, Yang S, Ahn Y, Lee NK. Analysis of Fluorescent Proteins for Observing Single Gene Locus in a Live and Fixed Escherichia coli Cell. J Phys Chem B 2024. [PMID: 38968413 DOI: 10.1021/acs.jpcb.4c01816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2024]
Abstract
Fluorescent proteins (FPs) are essential tools for advanced microscopy techniques such as super-resolution imaging, single-particle tracking, and quantitative single-molecule counting. Various FPs fused to DNA-binding proteins have been used to observe the subcellular location and movement of specific gene loci in living and fixed bacterial cells. However, quantitative assessments of the properties of FPs for gene locus measurements are still lacking. Here, we assessed various FPs to observe specific gene loci in live and fixed Escherichia coli cells using a fluorescent repressor-operator binding system (FROS), tet operator-Tet repressor proteins (TetR). Tsr-fused FPs were used to assess the intensity and photostability of various FPs (five red FPs: mCherry2, FusionRed, mRFP, mCrimson3, and dKatushka; and seven yellow FPs: SYFP2, Venus, mCitrine, YPet, mClover3, mTopaz, and EYFP) at the single-molecule level in living cells. These FPs were then used for gene locus measurements using FROS. Our results indicate that TetR-mCrimson3 (red) and TetR-EYFP (yellow) had better properties for visualizing gene loci than the other TetR-FPs. Furthermore, fixation procedures affected the clustering of diffusing TetR-FPs and altered the locations of the TetR-FP foci. Fixation with formaldehyde consistently disrupted proper DNA locus observations using TetR-FPs. Notably, the foci measured using TetR-mCrimson3 remained close to their original positions in live cells after glyoxal fixation. This in vivo study provides a cell-imaging guide for the use of FPs for gene-locus observation in E. coli and a scheme for evaluating the use of FPs for other cell-imaging purposes.
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Affiliation(s)
- Jung Bae Son
- Department of Chemistry, Seoul National University, 08826 Seoul, South Korea
| | - Seunghyeon Kim
- Department of Chemistry, Seoul National University, 08826 Seoul, South Korea
| | - Sora Yang
- Department of Chemistry, Seoul National University, 08826 Seoul, South Korea
| | - Youmin Ahn
- Department of Chemistry, Seoul National University, 08826 Seoul, South Korea
| | - Nam Ki Lee
- Department of Chemistry, Seoul National University, 08826 Seoul, South Korea
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2
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Presman DM, Benítez B, Lafuente AL, Vázquez Lareu A. Chromatin structure and dynamics: one nucleosome at a time. Histochem Cell Biol 2024; 162:79-90. [PMID: 38607419 DOI: 10.1007/s00418-024-02281-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2024] [Indexed: 04/13/2024]
Abstract
Eukaryotic genomes store information on many levels, including their linear DNA sequence, the posttranslational modifications of its constituents (epigenetic modifications), and its three-dimensional folding. Understanding how this information is stored and read requires multidisciplinary collaborations from many branches of science beyond biology, including physics, chemistry, and computer science. Concurrent recent developments in all these areas have enabled researchers to image the genome with unprecedented spatial and temporal resolution. In this review, we focus on what single-molecule imaging and tracking of individual proteins in live cells have taught us about chromatin structure and dynamics. Starting with the basics of single-molecule tracking (SMT), we describe some advantages over in situ imaging techniques and its current limitations. Next, we focus on single-nucleosome studies and what they have added to our current understanding of the relationship between chromatin dynamics and transcription. In celebration of Robert Feulgen's ground-breaking discovery that allowed us to start seeing the genome, we discuss current models of chromatin structure and future challenges ahead.
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Affiliation(s)
- Diego M Presman
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina.
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina.
| | - Belén Benítez
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina
- Instituto de Química Biológica (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina
| | - Agustina L Lafuente
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina
| | - Alejo Vázquez Lareu
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina
- Instituto de Química Biológica (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina
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3
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Hu S, Liu Y, Zhang Q, Bai J, Xu C. A continuum of zinc finger transcription factor retention on native chromatin underlies dynamic genome organization. Mol Syst Biol 2024; 20:799-824. [PMID: 38745107 PMCID: PMC11220090 DOI: 10.1038/s44320-024-00038-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 04/10/2024] [Accepted: 04/15/2024] [Indexed: 05/16/2024] Open
Abstract
Transcription factor (TF) residence on chromatin translates into quantitative transcriptional or structural outcomes on genome. Commonly used formaldehyde crosslinking fixes TF-DNA interactions cumulatively and compromises the measured occupancy level. Here we mapped the occupancy level of global or individual zinc finger TFs like CTCF and MAZ, in the form of highly resolved footprints, on native chromatin. By incorporating reinforcing perturbation conditions, we established S-score, a quantitative metric to proxy the continuum of CTCF or MAZ retention across different motifs on native chromatin. The native chromatin-retained CTCF sites harbor sequence features within CTCF motifs better explained by S-score than the metrics obtained from other crosslinking or native assays. CTCF retention on native chromatin correlates with local SUMOylation level, and anti-correlates with transcriptional activity. The S-score successfully delineates the otherwise-masked differential stability of chromatin structures mediated by CTCF, or by MAZ independent of CTCF. Overall, our study established a paradigm continuum of TF retention across binding sites on native chromatin, explaining the dynamic genome organization.
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Affiliation(s)
- Siling Hu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- China National Center for Bioinformation, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yangying Liu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- China National Center for Bioinformation, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qifan Zhang
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- China National Center for Bioinformation, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Juan Bai
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- China National Center for Bioinformation, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chenhuan Xu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China.
- China National Center for Bioinformation, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
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4
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Benedict B, Kristensen SM, Duxin JP. What are the DNA lesions underlying formaldehyde toxicity? DNA Repair (Amst) 2024; 138:103667. [PMID: 38554505 DOI: 10.1016/j.dnarep.2024.103667] [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: 12/15/2023] [Revised: 02/22/2024] [Accepted: 03/01/2024] [Indexed: 04/01/2024]
Abstract
Formaldehyde is a highly reactive organic compound. Humans can be exposed to exogenous sources of formaldehyde, but formaldehyde is also produced endogenously as a byproduct of cellular metabolism. Because formaldehyde can react with DNA, it is considered a major endogenous source of DNA damage. However, the nature of the lesions underlying formaldehyde toxicity in cells remains vastly unknown. Here, we review the current knowledge of the different types of nucleic acid lesions that are induced by formaldehyde and describe the repair pathways known to counteract formaldehyde toxicity. Taking this knowledge together, we discuss and speculate on the predominant lesions generated by formaldehyde, which underly its natural toxicity.
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Affiliation(s)
- Bente Benedict
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Stella Munkholm Kristensen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Julien P Duxin
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark.
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5
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Pantier R, Brown M, Han S, Paton K, Meek S, Montavon T, Shukeir N, McHugh T, Kelly DA, Hochepied T, Libert C, Jenuwein T, Burdon T, Bird A. MeCP2 binds to methylated DNA independently of phase separation and heterochromatin organisation. Nat Commun 2024; 15:3880. [PMID: 38719804 PMCID: PMC11079052 DOI: 10.1038/s41467-024-47395-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 03/29/2024] [Indexed: 05/12/2024] Open
Abstract
Correlative evidence has suggested that the methyl-CpG-binding protein MeCP2 contributes to the formation of heterochromatin condensates via liquid-liquid phase separation. This interpretation has been reinforced by the observation that heterochromatin, DNA methylation and MeCP2 co-localise within prominent foci in mouse cells. The findings presented here revise this view. MeCP2 localisation is independent of heterochromatin as MeCP2 foci persist even when heterochromatin organisation is disrupted. Additionally, MeCP2 foci fail to show hallmarks of phase separation in live cells. Importantly, we find that mouse cellular models are highly atypical as MeCP2 distribution is diffuse in most mammalian species, including humans. Notably, MeCP2 foci are absent in Mus spretus which is a mouse subspecies lacking methylated satellite DNA repeats. We conclude that MeCP2 has no intrinsic tendency to form condensates and its localisation is independent of heterochromatin. Instead, the distribution of MeCP2 in the nucleus is primarily determined by global DNA methylation patterns.
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Affiliation(s)
- Raphaël Pantier
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Megan Brown
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Sicheng Han
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Katie Paton
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Stephen Meek
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Thomas Montavon
- Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108, Freiburg, Germany
| | - Nicholas Shukeir
- Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108, Freiburg, Germany
| | - Toni McHugh
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - David A Kelly
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Tino Hochepied
- Center for Inflammation Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Claude Libert
- Center for Inflammation Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Thomas Jenuwein
- Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108, Freiburg, Germany
| | - Tom Burdon
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Adrian Bird
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK.
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6
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Gómez Acuña LI, Flyamer I, Boyle S, Friman ET, Bickmore WA. Transcription decouples estrogen-dependent changes in enhancer-promoter contact frequencies and spatial proximity. PLoS Genet 2024; 20:e1011277. [PMID: 38781242 DOI: 10.1371/journal.pgen.1011277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 06/05/2024] [Accepted: 04/29/2024] [Indexed: 05/25/2024] Open
Abstract
How enhancers regulate their target genes in the context of 3D chromatin organization is extensively studied and models which do not require direct enhancer-promoter contact have recently emerged. Here, we use the activation of estrogen receptor-dependent enhancers in a breast cancer cell line to study enhancer-promoter communication at two loci. This allows high temporal resolution tracking of molecular events from hormone stimulation to efficient gene activation. We examine how both enhancer-promoter spatial proximity assayed by DNA fluorescence in situ hybridization, and contact frequencies resulting from chromatin in situ fragmentation and proximity ligation, change dynamically during enhancer-driven gene activation. These orthogonal methods produce seemingly paradoxical results: upon enhancer activation enhancer-promoter contact frequencies increase while spatial proximity decreases. We explore this apparent discrepancy using different estrogen receptor ligands and transcription inhibitors. Our data demonstrate that enhancer-promoter contact frequencies are transcription independent whereas altered enhancer-promoter proximity depends on transcription. Our results emphasize that the relationship between contact frequencies and physical distance in the nucleus, especially over short genomic distances, is not always a simple one.
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Affiliation(s)
- Luciana I Gómez Acuña
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road, Edinburgh, United Kingdom
| | - Ilya Flyamer
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road, Edinburgh, United Kingdom
| | - Shelagh Boyle
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road, Edinburgh, United Kingdom
| | - Elias T Friman
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road, Edinburgh, United Kingdom
| | - Wendy A Bickmore
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road, Edinburgh, United Kingdom
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7
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Li Q, Hariri S, Calidas A, Kaur A, Huey E, Engebrecht J. The chromatin-associated 53BP1 ortholog, HSR-9, regulates recombinational repair and X chromosome segregation in the Caenorhabditis elegans germ line. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.12.589267. [PMID: 38659880 PMCID: PMC11042201 DOI: 10.1101/2024.04.12.589267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
53BP1 plays a crucial role in regulating DNA damage repair pathway choice and checkpoint signaling in somatic cells; however, its role in meiosis has remained enigmatic. In this study, we demonstrate that the Caenorhabditis elegans ortholog of 53BP1, HSR-9, associates with chromatin in both proliferating and meiotic germ cells. Notably, HSR-9 is enriched on the X chromosome pair in pachytene oogenic germ cells. HSR-9 is also present at kinetochores during both mitotic and meiotic divisions but does not appear to be essential for monitoring microtubule-kinetochore attachments or tension. Using cytological markers of different steps in recombinational repair, we found that HSR-9 influences the processing of a subset of meiotic double strand breaks into COSA-1-marked crossovers. Additionally, HSR-9 plays a role in meiotic X chromosome segregation under conditions where X chromosomes fail to pair, synapse, and recombine. Together, these results highlight that chromatin-associated HSR-9 has both conserved and unique functions in the regulation of meiotic chromosome behavior.
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Affiliation(s)
- Qianyan Li
- Department of Molecular and Cellular Biology, University of California Davis, Davis, California 95616
- Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California Davis, Davis, California 95616
| | - Sara Hariri
- Department of Molecular and Cellular Biology, University of California Davis, Davis, California 95616
- Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California Davis, Davis, California 95616
| | - Aashna Calidas
- Department of Molecular and Cellular Biology, University of California Davis, Davis, California 95616
| | - Arshdeep Kaur
- Department of Molecular and Cellular Biology, University of California Davis, Davis, California 95616
| | - Erica Huey
- Department of Molecular and Cellular Biology, University of California Davis, Davis, California 95616
| | - JoAnne Engebrecht
- Department of Molecular and Cellular Biology, University of California Davis, Davis, California 95616
- Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California Davis, Davis, California 95616
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8
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Taglini F, Kafetzopoulos I, Rolls W, Musialik KI, Lee HY, Zhang Y, Marenda M, Kerr L, Finan H, Rubio-Ramon C, Gautier P, Wapenaar H, Kumar D, Davidson-Smith H, Wills J, Murphy LC, Wheeler A, Wilson MD, Sproul D. DNMT3B PWWP mutations cause hypermethylation of heterochromatin. EMBO Rep 2024; 25:1130-1155. [PMID: 38291337 PMCID: PMC7615734 DOI: 10.1038/s44319-024-00061-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 12/21/2023] [Accepted: 12/21/2023] [Indexed: 02/01/2024] Open
Abstract
The correct establishment of DNA methylation patterns is vital for mammalian development and is achieved by the de novo DNA methyltransferases DNMT3A and DNMT3B. DNMT3B localises to H3K36me3 at actively transcribing gene bodies via its PWWP domain. It also functions at heterochromatin through an unknown recruitment mechanism. Here, we find that knockout of DNMT3B causes loss of methylation predominantly at H3K9me3-marked heterochromatin and that DNMT3B PWWP domain mutations or deletion result in striking increases of methylation in H3K9me3-marked heterochromatin. Removal of the N-terminal region of DNMT3B affects its ability to methylate H3K9me3-marked regions. This region of DNMT3B directly interacts with HP1α and facilitates the bridging of DNMT3B with H3K9me3-marked nucleosomes in vitro. Our results suggest that DNMT3B is recruited to H3K9me3-marked heterochromatin in a PWWP-independent manner that is facilitated by the protein's N-terminal region through an interaction with a key heterochromatin protein. More generally, we suggest that DNMT3B plays a role in DNA methylation homeostasis at heterochromatin, a process which is disrupted in cancer, aging and Immunodeficiency, Centromeric Instability and Facial Anomalies (ICF) syndrome.
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Affiliation(s)
- Francesca Taglini
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Ioannis Kafetzopoulos
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- Altos Labs, Cambridge Institute, Cambridge, UK
| | - Willow Rolls
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Kamila Irena Musialik
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- MRC London Institute of Medical Sciences and Institute of Clinical Sciences, Imperial College London, London, UK
| | - Heng Yang Lee
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- Endocrine Oncology Research Group, Department of Surgery, The Royal College of Surgeons RCSI, University of Medicine and Health Sciences, Dublin, Ireland
| | - Yujie Zhang
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Mattia Marenda
- IEO, European Institute of Oncology IRCCS, Department of Experimental Oncology, Milan, Italy
| | - Lyndsay Kerr
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, UK
| | - Hannah Finan
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- Swiss Federal Institute of Technology, ETH Zürich, Institute of Molecular Health Sciences, Zürich, Switzerland
| | - Cristina Rubio-Ramon
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Philippe Gautier
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Hannah Wapenaar
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Dhananjay Kumar
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Hazel Davidson-Smith
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Jimi Wills
- CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Laura C Murphy
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Ann Wheeler
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Marcus D Wilson
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK.
| | - Duncan Sproul
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK.
- CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK.
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9
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Ishii S, Kakizuka T, Park SJ, Tagawa A, Sanbo C, Tanabe H, Ohkawa Y, Nakanishi M, Nakai K, Miyanari Y. Genome-wide ATAC-see screening identifies TFDP1 as a modulator of global chromatin accessibility. Nat Genet 2024; 56:473-482. [PMID: 38361031 DOI: 10.1038/s41588-024-01658-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 01/08/2024] [Indexed: 02/17/2024]
Abstract
Chromatin accessibility is a hallmark of active regulatory regions and is functionally linked to transcriptional networks and cell identity. However, the molecular mechanisms and networks that govern chromatin accessibility have not been thoroughly studied. Here we conducted a genome-wide CRISPR screening combined with an optimized ATAC-see protocol to identify genes that modulate global chromatin accessibility. In addition to known chromatin regulators like CREBBP and EP400, we discovered a number of previously unrecognized proteins that modulate chromatin accessibility, including TFDP1, HNRNPU, EIF3D and THAP11 belonging to diverse biological pathways. ATAC-seq analysis upon their knockouts revealed their distinct and specific effects on chromatin accessibility. Remarkably, we found that TFDP1, a transcription factor, modulates global chromatin accessibility through transcriptional regulation of canonical histones. In addition, our findings highlight the manipulation of chromatin accessibility as an approach to enhance various cell engineering applications, including genome editing and induced pluripotent stem cell reprogramming.
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Affiliation(s)
- Satoko Ishii
- The Graduate University for Advanced Studies, SOKENDAI, Okazaki, Japan
- National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
- Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Japan
| | - Taishi Kakizuka
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Sung-Joon Park
- Human Genome Center, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Ayako Tagawa
- WPI Nano Life Science Institute, Kanazawa University, Kanazawa, Japan
| | - Chiaki Sanbo
- National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
- Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Japan
| | - Hideyuki Tanabe
- Research Center for Integrative Evolutionary Science, SOKENDAI, Hayama, Japan
| | - Yasuyuki Ohkawa
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | | | - Kenta Nakai
- Human Genome Center, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Yusuke Miyanari
- WPI Nano Life Science Institute, Kanazawa University, Kanazawa, Japan.
- Cancer Research Institute, Kanazawa University, Kanazawa, Japan.
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10
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Wang MF, Ritter MM, Kullman SW, Muddiman DC. Comparative analysis of sucrose-embedding for whole-body zebrafish MSI by IR-MALDESI. Anal Bioanal Chem 2023; 415:6389-6398. [PMID: 37640826 PMCID: PMC11132179 DOI: 10.1007/s00216-023-04914-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 08/13/2023] [Accepted: 08/15/2023] [Indexed: 08/31/2023]
Abstract
Infrared matrix-assisted laser desorption electrospray ionization mass spectrometry imaging (IR-MALDESI) conventionally utilizes fresh-frozen biological tissues with an ice matrix to improve the detection of analytes. Sucrose-embedding with paraformaldehyde fixation has demonstrated feasibility as an alternative matrix for analysis by IR-MALDESI by preserving tissue features and enhancing ionization of lipids. However, investigating multi-organ systems provides broader context for a biological study and can elucidate more information about a disease state as opposed to a single organ. Danio rerio, or zebrafish, are model organisms for various disease states and can be imaged as a multi-organ sample to analyze morphological and metabolomic preservation as a result of sample preparation. Herein, whole-body zebrafish were imaged to compare sucrose-embedding with paraformaldehyde fixation against conventional fresh-frozen sample preparation. Serial sections were analyzed with and without an ice matrix to evaluate if sucrose functions as an alternative energy-absorbing matrix for IR-MALDESI applications across whole-body tissues. The resulting four conditions were compared in terms of total putative lipid annotations and category diversity, coverage across the entire m/z range, and ion abundance. Ultimately, sucrose-embedded zebrafish had an increase in putative lipid annotations for the combination of putative annotations with and without the application of an ice matrix relative to fresh-frozen tissues which require the application of an ice matrix. Upon the use of an ice matrix, a greater number of high mass putative lipid annotations (e.g., glycerophospholipids, glycerolipids, and sphingolipids) were identified. Conversely, without an ice matrix, sucrose-embedded sections elucidated more putative annotations in lower molecular weight lipids, including fatty acyls and sterol lipids. Similar to the mouse brain model, sucrose-embedding increased putative lipid annotation and abundance for whole-body zebrafish.
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Affiliation(s)
- Mary F Wang
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
| | - Morgan M Ritter
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
- Toxicology Program, North Carolina State University, Raleigh, NC, USA
| | - Seth W Kullman
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
- Toxicology Program, North Carolina State University, Raleigh, NC, USA
| | - David C Muddiman
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA.
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11
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Li R, Huang D, Zhao Y, Yuan Y, Sun X, Dai Z, Huo D, Liu X, Helin K, Li MJ, Wu X. PR-DUB safeguards Polycomb repression through H2AK119ub1 restriction. Cell Prolif 2023; 56:e13457. [PMID: 36959757 PMCID: PMC10542648 DOI: 10.1111/cpr.13457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/01/2023] [Accepted: 03/11/2023] [Indexed: 03/25/2023] Open
Abstract
Polycomb group (PcG) proteins are critical chromatin regulators for cell fate control. The mono-ubiquitylation on histone H2AK119 (H2AK119ub1) is one of the well-recognized mechanisms for Polycomb repressive complex 1 (PRC1)-mediated transcription repression. Unexpectedly, the specific H2AK119 deubiquitylation complex composed by additional sex comb-like proteins and BAP1 has also been genetically characterized as Polycomb repressive deubiquitnase (PR-DUB) for unclear reasons. However, it remains a mystery whether and how PR-DUB deficiency affects chromatin states and cell fates through impaired PcG silencing. Here through a careful epigenomic analysis, we demonstrate that a bulk of H2AK119ub1 is diffusely distributed away from promoter regions and their enrichment is positively correlated with PRC1 occupancy. Upon deletion of Asxl2 in mouse embryonic stem cells (ESCs), a pervasive gain of H2AK119ub1 is coincident with increased PRC1 sampling at chromatin. Accordingly, PRC1 is significantly lost from a subset of highly occupied promoters, leading to impaired silencing of associated genes before and after lineage differentiation of Asxl2-null ESCs. Therefore, our study highlights the importance of genome-wide H2AK119ub1 restriction by PR-DUB in safeguarding robust PRC1 deposition and its roles in developmental regulation.
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Affiliation(s)
- Rui Li
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Dandan Huang
- Wuxi School of MedicineJiangnan UniversityWuxi214000China
| | - Yingying Zhao
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Ye Yuan
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Xiaoyu Sun
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Zhongye Dai
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Dawei Huo
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Xiaozhi Liu
- Pediatric Center, Tianjin Key Laboratory of Epigenetics for Organ Development of Premature InfantsThe Fifth Central Hospital of TianjinTianjin300450China
| | - Kristian Helin
- Biotech Research and Innovation CentreUniversity of CopenhagenCopenhagenDenmark
- The Institute of Cancer Research (ICR)LondonUK
| | - Mulin Jun Li
- Department of Bioinformatics, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
- Department of Epidemiology and Biostatistics, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and HospitalTianjin Medical UniversityTianjin300070China
| | - Xudong Wu
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
- Department of OrthopedicsTianjin Medical University General HospitalTianjin300052China
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12
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West AE. Imaging the binding of MECP2 to DNA. Genes Dev 2023; 37:863-864. [PMID: 37914350 PMCID: PMC10691463 DOI: 10.1101/gad.351285.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Mutations in the methyl-DNA binding domain of MECP2 cause Rett syndrome; however, distinct mutations are associated with different severity of the disease. Live-cell imaging and single-molecule tracking are sensitive methods to quantify the DNA binding affinity and diffusion dynamics of nuclear proteins. In this issue of Genes & Development, Zhou and colleagues (pp. 883-900) used these imaging methods to quantitatively describe the partial loss of DNA binding resulting from a novel pathological MECP2 mutation with intermediate disease severity. These data demonstrate how single-molecule tracking can advance understanding of the molecular mechanisms connecting MECP2 mutations with Rett syndrome pathophysiology.
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Affiliation(s)
- Anne E West
- Department of Neurobiology, Duke University School of Medicine, Durham, North Carolina 27710, USA
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13
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Williamson I, Boyle S, Grimes GR, Friman ET, Bickmore WA. Dispersal of PRC1 condensates disrupts polycomb chromatin domains and loops. Life Sci Alliance 2023; 6:e202302101. [PMID: 37487640 PMCID: PMC10366532 DOI: 10.26508/lsa.202302101] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/10/2023] [Accepted: 07/12/2023] [Indexed: 07/26/2023] Open
Abstract
Polycomb repressive complex 1 (PRC1) strongly influences 3D genome organization, mediating local chromatin compaction and clustering of target loci. Several PRC1 subunits have the capacity to form biomolecular condensates through liquid-liquid phase separation in vitro and when tagged and over-expressed in cells. Here, we use 1,6-hexanediol, which can disrupt liquid-like condensates, to examine the role of endogenous PRC1 biomolecular condensates on local and chromosome-wide clustering of PRC1-bound loci. Using imaging and chromatin immunoprecipitation, we show that PRC1-mediated chromatin compaction and clustering of targeted genomic loci-at different length scales-can be reversibly disrupted by the addition and subsequent removal of 1,6-hexanediol to mouse embryonic stem cells. Decompaction and dispersal of polycomb domains and clusters cannot be solely attributable to reduced PRC1 occupancy detected by chromatin immunoprecipitation following 1,6-hexanediol treatment as the addition of 2,5-hexanediol has similar effects on binding despite this alcohol not perturbing PRC1-mediated 3D clustering, at least at the sub-megabase and megabase scales. These results suggest that weak hydrophobic interactions between PRC1 molecules may have a role in polycomb-mediated genome organization.
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Affiliation(s)
- Iain Williamson
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Shelagh Boyle
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Graeme R Grimes
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Elias T Friman
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Wendy A Bickmore
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
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14
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Duval M, Yague-Sanz C, Turowski TW, Petfalski E, Tollervey D, Bachand F. The conserved RNA-binding protein Seb1 promotes cotranscriptional ribosomal RNA processing by controlling RNA polymerase I progression. Nat Commun 2023; 14:3013. [PMID: 37230993 DOI: 10.1038/s41467-023-38826-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 05/16/2023] [Indexed: 05/27/2023] Open
Abstract
Transcription by RNA polymerase I (RNAPI) represents most of the transcriptional activity in eukaryotic cells and is associated with the production of mature ribosomal RNA (rRNA). As several rRNA maturation steps are coupled to RNAPI transcription, the rate of RNAPI elongation directly influences processing of nascent pre-rRNA, and changes in RNAPI transcription rate can result in alternative rRNA processing pathways in response to growth conditions and stress. However, factors and mechanisms that control RNAPI progression by influencing transcription elongation rate remain poorly understood. We show here that the conserved fission yeast RNA-binding protein Seb1 associates with the RNAPI transcription machinery and promotes RNAPI pausing states along the rDNA. The overall faster progression of RNAPI at the rDNA in Seb1-deficient cells impaired cotranscriptional pre-rRNA processing and the production of mature rRNAs. Given that Seb1 also influences pre-mRNA processing by modulating RNAPII progression, our findings unveil Seb1 as a pause-promoting factor for RNA polymerases I and II to control cotranscriptional RNA processing.
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Affiliation(s)
- Maxime Duval
- RNA group, Department of Biochemistry & Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Carlo Yague-Sanz
- RNA group, Department of Biochemistry & Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
- URPHYM-GEMO, The University of Namur, 5000, Namur, Belgium
| | - Tomasz W Turowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | | | - David Tollervey
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - François Bachand
- RNA group, Department of Biochemistry & Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada.
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15
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Yoshida SR, Maity BK, Chong S. Visualizing Protein Localizations in Fixed Cells: Caveats and the Underlying Mechanisms. J Phys Chem B 2023; 127:4165-4173. [PMID: 37161904 DOI: 10.1021/acs.jpcb.3c01658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Fluorescence microscopy techniques have been widely adopted in biology for their ability to visualize the structure and dynamics of a wide range of cellular and subcellular processes. The specificity and sensitivity that these techniques afford have made them primary tools in the characterization of protein localizations within cells. Many of the fluorescence microscopy techniques require cells to be fixed via chemical or alternative methods before being imaged. However, some fixation methods have been found to induce the redistribution of particular proteins in the cell, resulting in artifacts in the characterization of protein localizations and functions under physiological conditions. Here, we review the ability of commonly used cell fixation methods to faithfully preserve the localizations of proteins that bind to chromatin, undergo liquid-liquid phase separation (LLPS), and are involved in the formation of various membrane-bound organelles. We also review the mechanisms underlying various fixation artifacts and discuss potential alternative fixation methods to minimize the artifacts while investigating different proteins and cellular structures. Overall, fixed-cell fluorescence microscopy is a very powerful tool in biomedical research; however, each experiment demands the careful selection of an appropriate fixation method to avoid potential artifacts and may benefit from live-cell imaging validation.
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Affiliation(s)
- Shawn R Yoshida
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Barun K Maity
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Shasha Chong
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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16
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Wang MF, Sohn AL, Samal J, Erning K, Segura T, Muddiman DC. Lipidomic Analysis of Mouse Brain to Evaluate the Efficacy and Preservation of Different Tissue Preparatory Techniques by IR-MALDESI-MSI. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:869-877. [PMID: 36988291 DOI: 10.1021/jasms.2c00353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Numerous preparatory methods have been developed to preserve the cellular and structural integrity of various biological tissues for different -omics studies. Herein, two preparatory methods for mass spectrometry imaging (MSI) were evaluated, fresh-frozen and sucrose-embedded, paraformaldehyde (PFA) fixed, in terms of ion abundance, putative lipid identifications, and preservation of analyte spatial distributions. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI)-MSI was utilized to compare the preparatory methods of interest with and without the use of the conventional ice matrix. There were 2.5-fold and 1.6-fold more lipid species putatively identified in positive- and negative-ion modes, respectively, for sucrose-embedded, PFA-fixed tissues without an ice matrix relative to the current IR-MALDESI-MSI gold-standard, fresh-frozen tissue preparation with an exogenous ice matrix. Furthermore, sucrose-embedded tissues demonstrated improved spatial distribution of ions resulting from the cryo-protective property of sucrose and paraformaldehyde fixation. Evidence from these investigations supports sucrose-embedding without ice matrix as an alternative preparatory technique for IR-MALDESI-MSI.
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Affiliation(s)
- Mary F Wang
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Alexandria L Sohn
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Juhi Samal
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Kevin Erning
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Tatiana Segura
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, United States
| | - David C Muddiman
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
- Molecular Education, Technology and Research Innovation Center, North Carolina State University, Raleigh, North Carolina 27695, United States
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17
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Arabiotorre A, Formanowicz M, Bankaitis VA, Grabon A. Phosphatidylinositol-4-phosphate signaling regulates dense granule biogenesis and exocytosis in Toxoplasma gondii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.09.523261. [PMID: 36712082 PMCID: PMC9882004 DOI: 10.1101/2023.01.09.523261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Phosphoinositide metabolism defines the foundation of a major signaling pathway that is conserved throughout the eukaryotic kingdom. The 4-OH phosphorylated phosphoinositides such as phosphatidylinositol-4-phosphate (PtdIns4P) and phosphatidylinositol-4,5-bisphosphate are particularly important molecules as these execute intrinsically essential activities required for the viability of all eukaryotic cells studied thus far. Using intracellular tachyzoites of the apicomplexan parasite Toxoplasma gondii as model for assessing primordial roles for PtdIns4P signaling, we demonstrate the presence of PtdIns4P pools in Golgi/trans-Golgi (TGN) system and in post-TGN compartments of the parasite. Moreover, we show that deficits in PtdIns4P signaling result in structural perturbation of compartments that house dense granule cargo with accompanying deficits in dense granule exocytosis. Taken together, the data report a direct role for PtdIns4P in dense granule biogenesis and exocytosis. The data further indicate that the biogenic pathway for secretion-competent dense granule formation in T. gondii is more complex than simple budding of fully matured dense granules from the TGN.
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Affiliation(s)
- Angela Arabiotorre
- Department of Cell Biology & Genetics, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas 77843-1114, USA
| | - Megan Formanowicz
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843-2128
| | - Vytas A. Bankaitis
- Department of Cell Biology & Genetics, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas 77843-1114, USA
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843-2128
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-2128
| | - Aby Grabon
- Department of Cell Biology & Genetics, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas 77843-1114, USA
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18
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Rapid Downregulation of H3K4me3 Binding to Immunoregulatory Genes in Altered Gravity in Primary Human M1 Macrophages. Int J Mol Sci 2022; 24:ijms24010603. [PMID: 36614046 PMCID: PMC9820304 DOI: 10.3390/ijms24010603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 12/31/2022] Open
Abstract
The sensitivity of human immune system cells to gravity changes has been investigated in numerous studies. Human macrophages mediate innate and thus rapid immune defense on the one hand and activate T- and B-cell-based adaptive immune response on the other hand. In this process they finally act as immunoeffector cells, and are essential for tissue regeneration and remodeling. Recently, we demonstrated in the human Jurkat T cell line that genes are differentially regulated in cluster structures under altered gravity. In order to study an in vivo near system of immunologically relevant human cells under physically real microgravity, we performed parabolic flight experiments with primary human M1 macrophages under highly standardized conditions and performed chromatin immunoprecipitation DNA sequencing (ChIP-Seq) for whole-genome epigenetic detection of the DNA-binding loci of the main transcription complex RNA polymerase II and the transcription-associated epigenetic chromatin modification H3K4me3. We identified an overall downregulation of H3K4me3 binding loci in altered gravity, which were unequally distributed inter- and intrachromosomally throughout the genome. Three-quarters of all affected loci were located on the p arm of the chromosomes chr5, chr6, chr9, and chr19. The genomic distribution of the downregulated H3K4me3 loci corresponds to a substantial extent to immunoregulatory genes. In microgravity, analysis of RNA polymerase II binding showed increased binding to multiple loci at coding sequences but decreased binding to central noncoding regions. Detection of altered DNA binding of RNA polymerase II provided direct evidence that gravity changes can lead to altered transcription. Based on this study, we hypothesize that the rapid transcriptional response to changing gravitational forces is specifically encoded in the epigenetic organization of chromatin.
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19
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Hoffmann FT, Kim M, Beh LY, Wang J, Vo PLH, Gelsinger DR, George JT, Acree C, Mohabir JT, Fernández IS, Sternberg SH. Selective TnsC recruitment enhances the fidelity of RNA-guided transposition. Nature 2022; 609:384-393. [PMID: 36002573 PMCID: PMC10583602 DOI: 10.1038/s41586-022-05059-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 06/29/2022] [Indexed: 01/25/2023]
Abstract
Bacterial transposons are pervasive mobile genetic elements that use distinct DNA-binding proteins for horizontal transmission. For example, Escherichia coli Tn7 homes to a specific attachment site using TnsD1, whereas CRISPR-associated transposons use type I or type V Cas effectors to insert downstream of target sites specified by guide RNAs2,3. Despite this targeting diversity, transposition invariably requires TnsB, a DDE-family transposase that catalyses DNA excision and insertion, and TnsC, a AAA+ ATPase that is thought to communicate between transposase and targeting proteins4. How TnsC mediates this communication and thereby regulates transposition fidelity has remained unclear. Here we use chromatin immunoprecipitation with sequencing to monitor in vivo formation of the type I-F RNA-guided transpososome, enabling us to resolve distinct protein recruitment events before integration. DNA targeting by the TniQ-Cascade complex is surprisingly promiscuous-hundreds of genomic off-target sites are sampled, but only a subset of those sites is licensed for TnsC and TnsB recruitment, revealing a crucial proofreading checkpoint. To advance the mechanistic understanding of interactions responsible for transpososome assembly, we determined structures of TnsC using cryogenic electron microscopy and found that ATP binding drives the formation of heptameric rings that thread DNA through the central pore, thereby positioning the substrate for downstream integration. Collectively, our results highlight the molecular specificity imparted by consecutive factor binding to genomic target sites during RNA-guided transposition, and provide a structural roadmap to guide future engineering efforts.
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Affiliation(s)
- Florian T Hoffmann
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Minjoo Kim
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Department of Biomedical Engineering, New York University Tandon School of Engineering, New York, NY, USA
| | - Leslie Y Beh
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Illumina Singapore Pte, Ltd., Singapore, Singapore
| | - Jing Wang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Phuc Leo H Vo
- Department of Molecular Pharmacology and Therapeutics, Columbia University, New York, NY, USA
- Vertex Pharmaceuticals, Boston, MA, USA
| | - Diego R Gelsinger
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Jerrin Thomas George
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Christopher Acree
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Jason T Mohabir
- Department of Computer Science, Columbia University, New York, NY, USA
- Genomic Center for Infectious Diseases, Broad Institute, Cambridge, MA, USA
| | - Israel S Fernández
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
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20
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Soares MAF, Oliveira RA, Castro DS. Function and regulation of transcription factors during mitosis-to-G1 transition. Open Biol 2022; 12:220062. [PMID: 35642493 PMCID: PMC9157305 DOI: 10.1098/rsob.220062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
During cell division, drastic cellular changes characteristic of mitosis result in the inactivation of the transcriptional machinery, and global downregulation of transcription. Sequence-specific transcription factors (TFs) have thus been considered mere bystanders, devoid of any regulatory function during mitosis. This view changed significantly in recent years, upon the conclusion that many TFs associate with condensed chromosomes during cell division, even occupying a fraction of their genomic target sites in mitotic chromatin. This finding was at the origin of the concept of mitotic bookmarking by TFs, proposed as a mechanism to propagate gene regulatory information across cell divisions, by facilitating the reactivation of specific bookmarked genes. While the underlying mechanisms and biological significance of this model remain elusive, recent developments in this fast-moving field have cast new light into TF activity during mitosis, beyond a bookmarking role. Here, we start by reviewing the most recent findings on the complex nature of TF-chromatin interactions during mitosis, and on mechanisms that may regulate them. Next, and in light of recent reports describing how transcription is reinitiated in temporally distinct waves during mitosis-to-G1 transition, we explore how TFs may contribute to defining this hierarchical gene expression process. Finally, we discuss how TF activity during mitotic exit may impact the acquisition of cell identity upon cell division, and propose a model that integrates dynamic changes in TF-chromatin interactions during this cell-cycle period, with the execution of cell-fate decisions.
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Affiliation(s)
- Mário A. F. Soares
- i3S Instituto de Investigação e Inovação em Saúde, IBMC Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | | | - Diogo S. Castro
- i3S Instituto de Investigação e Inovação em Saúde, IBMC Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
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21
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Wei YB, Luo D, Xiong X, Huang YL, Xie M, Lu W, Li D. Biomimetic mimicry of formaldehyde-induced DNA-protein crosslinks in the confined space of a metal-organic framework. Chem Sci 2022; 13:4813-4820. [PMID: 35655868 PMCID: PMC9067591 DOI: 10.1039/d2sc00188h] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/18/2022] [Indexed: 02/05/2023] Open
Abstract
DNA-protein crosslinks (DPCs) are highly toxic DNA lesions induced by crosslinking agents such as formaldehyde (HCHO). Building artificial models to simulate the crosslinking process would advance our understanding of the underlying mechanisms and therefore develop coping strategies accordingly. Herein we report the design and synthesis of a Zn-based metal-organic framework with mixed ligands of 2,6-diaminopurine and amine-functionalized dicarboxylate, representing DNA and protein residues, respectively. Combined characterization techniques allow us to demonstrate the unusual efficiency of HCHO-crosslinking within the confined space of the titled MOF. Particularly, in situ single-crystal X-ray diffraction studies reveal a sequential methylene-knitting process upon HCHO addition, along with strong fluorescence that was not interfered with by other metabolites, glycine, and Tris. This work has successfully constructed a purine-based metal-organic framework with unoccupied Watson-Crick sites, serving as a crystalline model for HCHO-induced DPCs by mimicking the confinement effect of protein/DNA interactions.
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Affiliation(s)
- Yu-Bai Wei
- College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University Guangzhou 510632 P. R. China
| | - Dong Luo
- College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University Guangzhou 510632 P. R. China
| | - Xiao Xiong
- College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University Guangzhou 510632 P. R. China
| | - Yong-Liang Huang
- Department of Chemistry, Shantou University Medical College Shantou Guangdong 515041 P. R. China
| | - Mo Xie
- College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University Guangzhou 510632 P. R. China
| | - Weigang Lu
- College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University Guangzhou 510632 P. R. China
| | - Dan Li
- College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University Guangzhou 510632 P. R. China
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22
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Venkata Suseela Y, Sengupta P, Roychowdhury T, Panda S, Talukdar S, Chattopadhyay S, Chatterjee S, Govindaraju T. Targeting Oncogene Promoters and Ribosomal RNA Biogenesis by G-Quadruplex Binding Ligands Translate to Anticancer Activity. ACS BIO & MED CHEM AU 2022; 2:125-139. [PMID: 37101746 PMCID: PMC10114666 DOI: 10.1021/acsbiomedchemau.1c00039] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
G-Quadruplex (GQ) nucleic acids are promising therapeutic targets in anticancer research due to their structural robustness, polymorphism, and gene-regulatory functions. Here, we presented the structure-activity relationship of carbazole-based monocyanine ligands using region-specific functionalization with benzothiazole (TCA and TCZ), lepidine (LCA and LCZ), and quinaldine (QCA and QCZ) acceptor moieties and evaluated their binding profiles with different oncogenic GQs. Their differential turn-on fluorescence emission upon GQ binding confirmed the GQ-to-duplex selectivity of all carbazole ligands, while the isothermal titration calorimetry results showed selective interactions of TCZ and TCA to c-MYC and BCL-2 GQs, respectively. The aldehyde group in TCA favors stacking interactions with the tetrad of BCL-2 GQ, whereas TCZ provides selective groove interactions with c-MYC GQ. Dual-luciferase assay and chromatin immunoprecipitation (ChIP) showed that these molecules interfere with the recruitment of specific transcription factors at c-MYC and BCL-2 promoters and stabilize the promoter GQ structures to inhibit their constitutive transcription in cancer cells. Their intrinsic turn-on fluorescence response with longer lifetimes upon GQ binding allowed real-time visualization of GQ structures at subcellular compartments. Confocal microscopy revealed the uptake of these ligands in the nucleoli, resulting in nucleolar stress. ChIP studies further confirmed the inhibition of Nucleolin occupancy at multiple GQ-enriched regions of ribosomal DNA (rDNA) promoters, which arrested rRNA biogenesis. Therefore, carbazole ligands act as the "double-edged swords" to arrest c-MYC and BCL-2 overexpression as well as rRNA biogenesis, triggering synergistic inhibition of multiple oncogenic pathways and apoptosis in cancer cells.
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Affiliation(s)
- Yelisetty Venkata Suseela
- Bioorganic
Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, P.O., Bengaluru, Karnataka 560064, India
| | - Pallabi Sengupta
- Department
of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kankurgachi, Kolkata 700054, India
| | - Tanaya Roychowdhury
- Cancer
Biology and Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700032, India
| | - Suman Panda
- Department
of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kankurgachi, Kolkata 700054, India
| | - Sangita Talukdar
- Bioorganic
Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, P.O., Bengaluru, Karnataka 560064, India
| | - Samit Chattopadhyay
- Cancer
Biology and Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700032, India
| | - Subhrangsu Chatterjee
- Department
of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kankurgachi, Kolkata 700054, India
| | - Thimmaiah Govindaraju
- Bioorganic
Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, P.O., Bengaluru, Karnataka 560064, India
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23
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Zhang H, Romero H, Schmidt A, Gagova K, Qin W, Bertulat B, Lehmkuhl A, Milden M, Eck M, Meckel T, Leonhardt H, Cardoso MC. MeCP2-induced heterochromatin organization is driven by oligomerization-based liquid–liquid phase separation and restricted by DNA methylation. Nucleus 2022; 13:1-34. [PMID: 35156529 PMCID: PMC8855868 DOI: 10.1080/19491034.2021.2024691] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Hui Zhang
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Hector Romero
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Annika Schmidt
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Katalina Gagova
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Weihua Qin
- Faculty of Biology, Ludwig Maximilians University Munich, Munich, Germany
| | - Bianca Bertulat
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Anne Lehmkuhl
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Manuela Milden
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Malte Eck
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Tobias Meckel
- Department of Chemistry, Technical University of Darmstadt, Darmstadt, Germany
| | - Heinrich Leonhardt
- Faculty of Biology, Ludwig Maximilians University Munich, Munich, Germany
| | - M. Cristina Cardoso
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
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24
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Irgen-Gioro S, Yoshida S, Walling V, Chong S. Fixation can change the appearance of phase separation in living cells. eLife 2022; 11:79903. [PMID: 36444977 PMCID: PMC9817179 DOI: 10.7554/elife.79903] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 11/28/2022] [Indexed: 11/30/2022] Open
Abstract
Fixing cells with paraformaldehyde (PFA) is an essential step in numerous biological techniques as it is thought to preserve a snapshot of biomolecular transactions in living cells. Fixed-cell imaging techniques such as immunofluorescence have been widely used to detect liquid-liquid phase separation (LLPS) in vivo. Here, we compared images, before and after fixation, of cells expressing intrinsically disordered proteins that are able to undergo LLPS. Surprisingly, we found that PFA fixation can both enhance and diminish putative LLPS behaviors. For specific proteins, fixation can even cause their droplet-like puncta to artificially appear in cells that do not have any detectable puncta in the live condition. Fixing cells in the presence of glycine, a molecule that modulates fixation rates, can reverse the fixation effect from enhancing to diminishing LLPS appearance. We further established a kinetic model of fixation in the context of dynamic protein-protein interactions. Simulations based on the model suggest that protein localization in fixed cells depends on an intricate balance of protein-protein interaction dynamics, the overall rate of fixation, and notably, the difference between fixation rates of different proteins. Consistent with simulations, live-cell single-molecule imaging experiments showed that a fast overall rate of fixation relative to protein-protein interaction dynamics can minimize fixation artifacts. Our work reveals that PFA fixation changes the appearance of LLPS from living cells, presents a caveat in studying LLPS using fixation-based methods, and suggests a mechanism underlying the fixation artifact.
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Affiliation(s)
- Shawn Irgen-Gioro
- Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaUnited States
| | - Shawn Yoshida
- Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaUnited States,Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Victoria Walling
- Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaUnited States
| | - Shasha Chong
- Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaUnited States
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25
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Dos Santos Passos C, Choi YS, Snow CD, Yao T, Cohen RE. Design of genetically encoded sensors to detect nucleosome ubiquitination in live cells. J Cell Biol 2021; 220:211785. [PMID: 33570569 PMCID: PMC7883740 DOI: 10.1083/jcb.201911130] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/22/2020] [Accepted: 01/04/2021] [Indexed: 02/07/2023] Open
Abstract
Histone posttranslational modifications (PTMs) are dynamic, context-dependent signals that modulate chromatin structure and function. Ubiquitin (Ub) conjugation to different lysines of histones H2A and H2B is used to regulate diverse processes such as gene silencing, transcriptional elongation, and DNA repair. Despite considerable progress made to elucidate the players and mechanisms involved in histone ubiquitination, there remains a lack of tools to monitor these PTMs, especially in live cells. To address this, we combined an avidity-based strategy with in silico approaches to design sensors for specifically ubiquitinated nucleosomes. By linking Ub-binding domains to nucleosome-binding peptides, we engineered proteins that target H2AK13/15Ub and H2BK120Ub with Kd values from 10−8 to 10−6 M; when fused to fluorescent proteins, they work as PTM sensors in cells. The H2AK13/15Ub-specific sensor, employed to monitor signaling from endogenous DNA damage through the cell cycle, identified and differentiated roles for 53BP1 and BARD1 as mediators of this histone PTM.
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Affiliation(s)
| | - Yun-Seok Choi
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO
| | - Christopher D Snow
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO.,Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO
| | - Tingting Yao
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO
| | - Robert E Cohen
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO
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26
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Brown K, Andrianakos H, Ingersoll S, Ren X. Single-molecule imaging of epigenetic complexes in living cells: insights from studies on Polycomb group proteins. Nucleic Acids Res 2021; 49:6621-6637. [PMID: 34009336 PMCID: PMC8266577 DOI: 10.1093/nar/gkab304] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 04/09/2021] [Accepted: 04/13/2021] [Indexed: 12/30/2022] Open
Abstract
Chromatin-associated factors must locate, bind to, and assemble on specific chromatin regions to execute chromatin-templated functions. These dynamic processes are essential for understanding how chromatin achieves regulation, but direct quantification in living mammalian cells remains challenging. Over the last few years, live-cell single-molecule tracking (SMT) has emerged as a new way to observe trajectories of individual chromatin-associated factors in living mammalian cells, providing new perspectives on chromatin-templated activities. Here, we discuss the relative merits of live-cell SMT techniques currently in use. We provide new insights into how Polycomb group (PcG) proteins, master regulators of development and cell differentiation, decipher genetic and epigenetic information to achieve binding stability and highlight that Polycomb condensates facilitate target-search efficiency. We provide perspectives on liquid-liquid phase separation in organizing Polycomb targets. We suggest that epigenetic complexes integrate genetic and epigenetic information for target binding and localization and achieve target-search efficiency through nuclear organization.
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Affiliation(s)
- Kyle Brown
- Department of Chemistry, University of Colorado Denver, Denver, CO 80217-3364, USA
| | | | - Steven Ingersoll
- Department of Chemistry, University of Colorado Denver, Denver, CO 80217-3364, USA
| | - Xiaojun Ren
- Department of Chemistry, University of Colorado Denver, Denver, CO 80217-3364, USA
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27
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Tilly BC, Chalkley GE, van der Knaap JA, Moshkin YM, Kan TW, Dekkers DH, Demmers JA, Verrijzer CP. In vivo analysis reveals that ATP-hydrolysis couples remodeling to SWI/SNF release from chromatin. eLife 2021; 10:69424. [PMID: 34313222 PMCID: PMC8352592 DOI: 10.7554/elife.69424] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/26/2021] [Indexed: 12/23/2022] Open
Abstract
ATP-dependent chromatin remodelers control the accessibility of genomic DNA through nucleosome mobilization. However, the dynamics of genome exploration by remodelers, and the role of ATP hydrolysis in this process remain unclear. We used live-cell imaging of Drosophila polytene nuclei to monitor Brahma (BRM) remodeler interactions with its chromosomal targets. In parallel, we measured local chromatin condensation and its effect on BRM association. Surprisingly, only a small portion of BRM is bound to chromatin at any given time. BRM binds decondensed chromatin but is excluded from condensed chromatin, limiting its genomic search space. BRM-chromatin interactions are highly dynamic, whereas histone-exchange is limited and much slower. Intriguingly, loss of ATP hydrolysis enhanced chromatin retention and clustering of BRM, which was associated with reduced histone turnover. Thus, ATP hydrolysis couples nucleosome remodeling to remodeler release, driving a continuous transient probing of the genome.
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Affiliation(s)
- Ben C Tilly
- Department of Biochemistry, Rotterdam, Netherlands
| | | | | | | | | | - Dick Hw Dekkers
- Department of Biochemistry, Rotterdam, Netherlands.,Proteomics Center, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Jeroen Aa Demmers
- Department of Biochemistry, Rotterdam, Netherlands.,Proteomics Center, Erasmus University Medical Center, Rotterdam, Netherlands
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28
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Huseyin MK, Klose RJ. Live-cell single particle tracking of PRC1 reveals a highly dynamic system with low target site occupancy. Nat Commun 2021; 12:887. [PMID: 33563969 PMCID: PMC7873255 DOI: 10.1038/s41467-021-21130-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 01/13/2021] [Indexed: 01/04/2023] Open
Abstract
Polycomb repressive complex 1 (PRC1) is an essential chromatin-based repressor of gene transcription. How PRC1 engages with chromatin to identify its target genes and achieve gene repression remains poorly defined, representing a major hurdle to our understanding of Polycomb system function. Here, we use genome engineering and single particle tracking to dissect how PRC1 binds to chromatin in live mouse embryonic stem cells. We observe that PRC1 is highly dynamic, with only a small fraction stably interacting with chromatin. By integrating subunit-specific dynamics, chromatin binding, and abundance measurements, we discover that PRC1 exhibits low occupancy at target sites. Furthermore, we employ perturbation approaches to uncover how specific components of PRC1 define its kinetics and chromatin binding. Together, these discoveries provide a quantitative understanding of chromatin binding by PRC1 in live cells, suggesting that chromatin modification, as opposed to PRC1 complex occupancy, is central to gene repression.
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Affiliation(s)
- Miles K Huseyin
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Robert J Klose
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
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29
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Tillotson R, Cholewa-Waclaw J, Chhatbar K, Connelly JC, Kirschner SA, Webb S, Koerner MV, Selfridge J, Kelly DA, De Sousa D, Brown K, Lyst MJ, Kriaucionis S, Bird A. Neuronal non-CG methylation is an essential target for MeCP2 function. Mol Cell 2021; 81:1260-1275.e12. [PMID: 33561390 PMCID: PMC7980222 DOI: 10.1016/j.molcel.2021.01.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/17/2020] [Accepted: 01/07/2021] [Indexed: 02/07/2023]
Abstract
DNA methylation is implicated in neuronal biology via the protein MeCP2, the mutation of which causes Rett syndrome. MeCP2 recruits the NCOR1/2 co-repressor complexes to methylated cytosine in the CG dinucleotide, but also to sites of non-CG methylation, which are abundant in neurons. To test the biological significance of the dual-binding specificity of MeCP2, we replaced its DNA binding domain with an orthologous domain from MBD2, which can only bind mCG motifs. Knockin mice expressing the domain-swap protein displayed severe Rett-syndrome-like phenotypes, indicating that normal brain function requires the interaction of MeCP2 with sites of non-CG methylation, specifically mCAC. The results support the notion that the delayed onset of Rett syndrome is due to the simultaneous post-natal accumulation of mCAC and its reader MeCP2. Intriguingly, genes dysregulated in both Mecp2 null and domain-swap mice are implicated in other neurological disorders, potentially highlighting targets of relevance to the Rett syndrome phenotype.
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Affiliation(s)
- Rebekah Tillotson
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Justyna Cholewa-Waclaw
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Kashyap Chhatbar
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - John C Connelly
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Sophie A Kirschner
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Shaun Webb
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Martha V Koerner
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Jim Selfridge
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - David A Kelly
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Dina De Sousa
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Kyla Brown
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Matthew J Lyst
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Skirmantas Kriaucionis
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK.
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30
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de Jonge WJ, Brok M, Kemmeren P, Holstege FCP. An Optimized Chromatin Immunoprecipitation Protocol for Quantification of Protein-DNA Interactions. STAR Protoc 2020; 1:100020. [PMID: 32685929 PMCID: PMC7357673 DOI: 10.1016/j.xpro.2020.100020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Transcription factors are important regulators of cell fate and function. Knowledge about where transcription factors are bound in the genome is crucial for understanding their function. A common method to study protein-DNA interactions is chromatin immunoprecipitation (ChIP). Here, we present a revised ChIP protocol to determine protein-DNA interactions for the yeast Saccharomyces cerevisiae. We optimized several aspects of the procedure, including cross-linking and quenching, cell lysis, and immunoprecipitation steps. This protocol facilitates sensitive and reproducible quantitation of protein-DNA interactions. For complete details on the use and execution of this protocol, please refer to (de Jonge et al., 2019). Chromatin immunoprecipitation protocol to quantify protein-DNA interactions Optimized for sensitivity and robustness Optimized for quantitative comparisons between experiments, e.g., in time series Highlights common ChIP pitfalls, variable steps, and how to increase reproducibility
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Affiliation(s)
- Wim J de Jonge
- Princess Máxima Center for Pediatric Oncology, Heidelberglaan 25, 3584 CS Utrecht, the Netherlands
| | - Mariël Brok
- Princess Máxima Center for Pediatric Oncology, Heidelberglaan 25, 3584 CS Utrecht, the Netherlands
| | - Patrick Kemmeren
- Princess Máxima Center for Pediatric Oncology, Heidelberglaan 25, 3584 CS Utrecht, the Netherlands
| | - Frank C P Holstege
- Princess Máxima Center for Pediatric Oncology, Heidelberglaan 25, 3584 CS Utrecht, the Netherlands
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31
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Yildirim O, Izgu EC, Damle M, Chalei V, Ji F, Sadreyev RI, Szostak JW, Kingston RE. S-phase Enriched Non-coding RNAs Regulate Gene Expression and Cell Cycle Progression. Cell Rep 2020; 31:107629. [PMID: 32402276 PMCID: PMC7954657 DOI: 10.1016/j.celrep.2020.107629] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 02/20/2020] [Accepted: 04/20/2020] [Indexed: 12/13/2022] Open
Abstract
Many proteins that are needed for progression through S-phase are produced from transcripts that peak in the S-phase, linking temporal expression of those proteins to the time that they are required in cell cycle. Here, we explore the potential roles of long non-coding RNAs in cell cycle progression. We use a sensitive click-chemistry approach to isolate nascent RNAs in a human cell line, and we identify more than 900 long non-coding RNAs (lncRNAs) whose synthesis peaks during the S-phase. More than 200 of these are long intergenic non-coding RNAs (lincRNAs) with S-phase-specific expression. We characterize three of these lincRNAs by knockdown and find that all three lincRNAs are required for appropriate S-phase progression. We infer that non-coding RNAs are key regulatory effectors during the cell cycle, acting on distinct regulatory networks, and herein, we provide a large catalog of candidate cell-cycle regulatory RNAs.
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Affiliation(s)
- Ozlem Yildirim
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Enver C Izgu
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Manashree Damle
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Vladislava Chalei
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Fei Ji
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Ruslan I Sadreyev
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Jack W Szostak
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Robert E Kingston
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
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32
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Tillotson R, Bird A. The Molecular Basis of MeCP2 Function in the Brain. J Mol Biol 2020; 432:1602-1623. [PMID: 31629770 DOI: 10.1016/j.jmb.2019.10.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/04/2019] [Accepted: 10/05/2019] [Indexed: 12/14/2022]
Abstract
MeCP2 is a reader of the DNA methylome that occupies a large proportion of the genome due to its high abundance and the frequency of its target sites. It has been the subject of extensive study because of its link with 'MECP2-related disorders', of which Rett syndrome is the most prevalent. This review integrates evidence from patient mutation data with results of experimental studies using mouse models, cell lines and in vitro systems to critically evaluate our understanding of MeCP2 protein function. Recent evidence challenges the idea that MeCP2 is a multifunctional hub that integrates diverse processes to underpin neuronal function, suggesting instead that its primary role is to recruit the NCoR1/2 co-repressor complex to methylated sites in the genome, leading to dampening of gene expression.
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Affiliation(s)
- Rebekah Tillotson
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada; Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK.
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33
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Purification and enrichment of specific chromatin loci. Nat Methods 2020; 17:380-389. [PMID: 32152500 DOI: 10.1038/s41592-020-0765-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 01/29/2020] [Indexed: 12/20/2022]
Abstract
Understanding how chromatin is regulated is essential to fully grasp genome biology, and establishing the locus-specific protein composition is a major step toward this goal. Here we explain why the isolation and analysis of a specific chromatin segment are technically challenging, independently of the method. We then describe the published strategies and discuss their advantages and limitations. We conclude by discussing why significant technology developments are required to unambiguously describe the composition of small single loci.
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34
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Affinity for DNA Contributes to NLS Independent Nuclear Localization of MeCP2. Cell Rep 2020; 24:2213-2220. [PMID: 30157418 PMCID: PMC6130050 DOI: 10.1016/j.celrep.2018.07.099] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 06/22/2018] [Accepted: 07/26/2018] [Indexed: 12/14/2022] Open
Abstract
MeCP2 is a nuclear protein that is mutated in the severe neurological disorder Rett syndrome (RTT). The ability to target β-galactosidase to the nucleus was previously used to identify a conserved nuclear localization signal (NLS) in MeCP2 that interacts with the nuclear import factors KPNA3 and KPNA4. Here, we report that nuclear localization of MeCP2 does not depend on its NLS. Instead, our data reveal that an intact methyl-CpG binding domain (MBD) is sufficient for nuclear localization, suggesting that MeCP2 can be retained in the nucleus by its affinity for DNA. Consistent with these findings, we demonstrate that disease progression in a mouse model of RTT is unaffected by an inactivating mutation in the NLS of MeCP2. Taken together, our work reveals an unexpected redundancy between functional domains of MeCP2 in targeting this protein to the nucleus, potentially explaining why NLS-inactivating mutations are rarely associated with disease. Nuclear localization of MeCP2 does not require its NLS DNA binding by MeCP2 contributes to its NLS-independent nuclear localization MeCP2 NLS mutation does not affect pathology in a mouse model of Rett syndrome
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35
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Policastro RA, Zentner GE. Enzymatic methods for genome-wide profiling of protein binding sites. Brief Funct Genomics 2019; 17:138-145. [PMID: 29028882 DOI: 10.1093/bfgp/elx030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Genome-wide mapping of protein-DNA interactions is a staple approach in many areas of modern molecular biology. Genome-wide profiles of protein-binding sites are most commonly generated by chromatin immunoprecipitation and high-throughput sequencing (ChIP-seq). Although ChIP-seq has played a central role in studying genome-wide protein binding, recent work has highlighted systematic biases in the technique that warrant technical and interpretive caution and underscore the need for orthogonal techniques to both confirm the results of ChIP-seq studies and uncover new insights not accessible to ChIP. Several such techniques, based on genetic or immunological targeting of enzymatic activity to specific genomic loci, have been developed. Here, we review the development, applications and future prospects of these methods as complements to ChIP-based approaches and as powerful techniques in their own right.
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Ouimet CM, Dawod M, Grinias J, Assimon VA, Lodge J, Mapp AK, Gestwicki JE, Kennedy RT. Protein cross-linking capillary electrophoresis at increased throughput for a range of protein-protein interactions. Analyst 2019; 143:1805-1812. [PMID: 29565056 DOI: 10.1039/c7an02098h] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tools for measuring affinities and stoichiometries of protein-protein complexes are valuable for elucidating the role of protein-protein interactions (PPIs) in governing cell functions and screening for PPI modulators. Such measurements can be challenging because PPIs can span a wide range of affinities and include stoichiometries from dimers to high order oligomers. Also, most techniques require large amounts of protein which can hamper research for difficult to obtain proteins. Protein cross-linking capillary electrophoresis (PXCE) has the potential to directly measure PPIs and even resolve multiple PPIs while consuming attomole quantities. Previously PXCE has only been used for high affinity, 1 : 1 complexes; here we expand the utility of PXCE to access a wide range of PPIs including weak and multimeric oligomers. Use of glutaraldehyde as the cross-linking agent was key to advancing the method because of its rapid reaction kinetics. A 10 s reaction time was found to be sufficient for cross-linking and quantification of seven different PPIs with Kd values ranging from low μM to low nM including heat shock protein 70 (Hsp70) interacting with heat shock organizing protein (3.8 ± 0.7 μM) and bcl2 associated anthanogene (26 ± 6 nM). Non-specific cross-linking of protein aggregates was found to be minimal at protein concentrations <20 μM as assessed by size exclusion chromatography. PXCE was sensitive enough to measure changes in PPI affinity induced by the protein nucleotide state or point mutations in the protein-binding site. Further, several interactions could be resolved in a single run, including Hsp70 monomer, homodimer and Hsp70 complexed the with c-terminus of Hsp70 interacting protein (CHIP). Finally, the throughput of PXCE was increased to 1 min per sample suggesting potential for utility in screening.
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Affiliation(s)
- Claire M Ouimet
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Mohamed Dawod
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - James Grinias
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA. and Department of Chemistry, Rowan University, Glassboro, NJ 08028, USA
| | - Victoria A Assimon
- Department of Pharmaceutical Chemistry, University of California at San Francisco, California 94158, USA
| | - Jean Lodge
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Anna K Mapp
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA. and Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry, University of California at San Francisco, California 94158, USA
| | - Robert T Kennedy
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA. and Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
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Singh AA, Schuurman K, Nevedomskaya E, Stelloo S, Linder S, Droog M, Kim Y, Sanders J, van der Poel H, Bergman AM, Wessels LF, Zwart W. Optimized ChIP-seq method facilitates transcription factor profiling in human tumors. Life Sci Alliance 2018; 2:e201800115. [PMID: 30620009 PMCID: PMC6311467 DOI: 10.26508/lsa.201800115] [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: 06/25/2018] [Revised: 12/18/2018] [Accepted: 12/18/2018] [Indexed: 01/27/2023] Open
Abstract
This study presents an optimized ChIP-seq protocol to enhance transcription factor profiling in human tumours, enabling the analysis of highly challenging samples, including core needle biopsies. Chromatin immunoprecipitation (ChIP)-seq analyses of transcription factors in clinical specimens are challenging due to the technical limitations and low quantities of starting material, often resulting in low enrichments and poor signal-to-noise ratio. Here, we present an optimized protocol for transcription factor ChIP-seq analyses in human tissue, yielding an ∼100% success rate for all transcription factors analyzed. As proof of concept and to illustrate general applicability of the approach, human tissue from the breast, prostate, and endometrial cancers were analyzed. In addition to standard formaldehyde fixation, disuccinimidyl glutarate was included in the procedure, greatly increasing data quality. To illustrate the sensitivity of the optimized protocol, we provide high-quality ChIP-seq data for three independent factors (AR, FOXA1, and H3K27ac) from a single core needle prostate cancer biopsy specimen. In summary, double-cross-linking strongly improved transcription factor ChIP-seq quality on human tumor samples, further facilitating and enhancing translational research on limited amounts of tissue.
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Affiliation(s)
- Abhishek A Singh
- Divisions of Oncogenomics, Oncode Institute, Netherlands Cancer Institute, Amsterdam, the Netherlands.,Molecular Carcinogenesis, Oncode Institute, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Karianne Schuurman
- Divisions of Oncogenomics, Oncode Institute, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Ekaterina Nevedomskaya
- Divisions of Oncogenomics, Oncode Institute, Netherlands Cancer Institute, Amsterdam, the Netherlands.,Molecular Carcinogenesis, Oncode Institute, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Suzan Stelloo
- Divisions of Oncogenomics, Oncode Institute, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Simon Linder
- Divisions of Oncogenomics, Oncode Institute, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Marjolein Droog
- Divisions of Oncogenomics, Oncode Institute, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Yongsoo Kim
- Divisions of Oncogenomics, Oncode Institute, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Joyce Sanders
- Department of Pathology, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Henk van der Poel
- Department of Urology, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Andries M Bergman
- Division of Oncogenomics, Netherlands Cancer Institute, Amsterdam, the Netherlands.,Division of Medical Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Lodewyk Fa Wessels
- Molecular Carcinogenesis, Oncode Institute, Netherlands Cancer Institute, Amsterdam, the Netherlands.,Faculty of Electrical Engineering, Mathematics, and Computer Science, Delft University of Technology, Delft, the Netherlands
| | - Wilbert Zwart
- Divisions of Oncogenomics, Oncode Institute, Netherlands Cancer Institute, Amsterdam, the Netherlands.,Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
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Schneider A, Niemeyer CM. DNA Surface Technology: From Gene Sensors to Integrated Systems for Life and Materials Sciences. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201811713] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Ann‐Kathrin Schneider
- Institute for Biological Interfaces (IBG 1) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 76344 Eggenstein-Leopoldshafen Germany
| | - Christof M. Niemeyer
- Institute for Biological Interfaces (IBG 1) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 76344 Eggenstein-Leopoldshafen Germany
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39
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Schneider A, Niemeyer CM. DNA Surface Technology: From Gene Sensors to Integrated Systems for Life and Materials Sciences. Angew Chem Int Ed Engl 2018; 57:16959-16967. [DOI: 10.1002/anie.201811713] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/15/2018] [Indexed: 01/21/2023]
Affiliation(s)
- Ann‐Kathrin Schneider
- Institute for Biological Interfaces (IBG 1) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 76344 Eggenstein-Leopoldshafen Germany
| | - Christof M. Niemeyer
- Institute for Biological Interfaces (IBG 1) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 76344 Eggenstein-Leopoldshafen Germany
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40
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Brown DA, Di Cerbo V, Feldmann A, Ahn J, Ito S, Blackledge NP, Nakayama M, McClellan M, Dimitrova E, Turberfield AH, Long HK, King HW, Kriaucionis S, Schermelleh L, Kutateladze TG, Koseki H, Klose RJ. The SET1 Complex Selects Actively Transcribed Target Genes via Multivalent Interaction with CpG Island Chromatin. Cell Rep 2018; 20:2313-2327. [PMID: 28877467 PMCID: PMC5603731 DOI: 10.1016/j.celrep.2017.08.030] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 07/19/2017] [Accepted: 08/06/2017] [Indexed: 12/24/2022] Open
Abstract
Chromatin modifications and the promoter-associated epigenome are important for the regulation of gene expression. However, the mechanisms by which chromatin-modifying complexes are targeted to the appropriate gene promoters in vertebrates and how they influence gene expression have remained poorly defined. Here, using a combination of live-cell imaging and functional genomics, we discover that the vertebrate SET1 complex is targeted to actively transcribed gene promoters through CFP1, which engages in a form of multivalent chromatin reading that involves recognition of non-methylated DNA and histone H3 lysine 4 trimethylation (H3K4me3). CFP1 defines SET1 complex occupancy on chromatin, and its multivalent interactions are required for the SET1 complex to place H3K4me3. In the absence of CFP1, gene expression is perturbed, suggesting that normal targeting and function of the SET1 complex are central to creating an appropriately functioning vertebrate promoter-associated epigenome. The CFP1/SET1 complex engages in dynamic and stable chromatin-binding events CFP1 uses multivalent chromatin interactions to select active CpG island promoters SET1A occupancy at CpG island promoters is predominately defined by CFP1 CFP1 targets SET1 to shape promoter-associated H3K4me3 and gene expression
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Affiliation(s)
- David A Brown
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Vincenzo Di Cerbo
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Angelika Feldmann
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Jaewoo Ahn
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Shinsuke Ito
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (IMS), 1-7-2 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Neil P Blackledge
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Manabu Nakayama
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (IMS), 1-7-2 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Michael McClellan
- Ludwig Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | - Emilia Dimitrova
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | | | - Hannah K Long
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Hamish W King
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Skirmantas Kriaucionis
- Ludwig Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Tatiana G Kutateladze
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Haruhiko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (IMS), 1-7-2 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Robert J Klose
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.
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Streubel G, Watson A, Jammula SG, Scelfo A, Fitzpatrick DJ, Oliviero G, McCole R, Conway E, Glancy E, Negri GL, Dillon E, Wynne K, Pasini D, Krogan NJ, Bracken AP, Cagney G. The H3K36me2 Methyltransferase Nsd1 Demarcates PRC2-Mediated H3K27me2 and H3K27me3 Domains in Embryonic Stem Cells. Mol Cell 2018; 70:371-379.e5. [PMID: 29606589 DOI: 10.1016/j.molcel.2018.02.027] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 12/22/2017] [Accepted: 02/23/2018] [Indexed: 12/12/2022]
Abstract
The Polycomb repressor complex 2 (PRC2) is composed of the core subunits Ezh1/2, Suz12, and Eed, and it mediates all di- and tri-methylation of histone H3 at lysine 27 in higher eukaryotes. However, little is known about how the catalytic activity of PRC2 is regulated to demarcate H3K27me2 and H3K27me3 domains across the genome. To address this, we mapped the endogenous interactomes of Ezh2 and Suz12 in embryonic stem cells (ESCs), and we combined this with a functional screen for H3K27 methylation marks. We found that Nsd1-mediated H3K36me2 co-locates with H3K27me2, and its loss leads to genome-wide expansion of H3K27me3. These increases in H3K27me3 occurred at PRC2/PRC1 target genes and as de novo accumulation within what were previously broad H3K27me2 domains. Our data support a model in which Nsd1 is a key modulator of PRC2 function required for regulating the demarcation of genome-wide H3K27me2 and H3K27me3 domains in ESCs.
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Affiliation(s)
- Gundula Streubel
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland; School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Ariane Watson
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Sri Ganesh Jammula
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Andrea Scelfo
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | | | - Giorgio Oliviero
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Rachel McCole
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Eric Conway
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Eleanor Glancy
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Gian Luca Negri
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Eugene Dillon
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Kieran Wynne
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Diego Pasini
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy; Department of Health Sciences, University of Milan, Via A. di Rudinì, 8, 20142 Milan, Italy
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94148, USA; Gladstone Institutes, San Francisco, CA 94158, USA
| | - Adrian P Bracken
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland.
| | - Gerard Cagney
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland.
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Almeida M, Pintacuda G, Masui O, Koseki Y, Gdula M, Cerase A, Brown D, Mould A, Innocent C, Nakayama M, Schermelleh L, Nesterova TB, Koseki H, Brockdorff N. PCGF3/5-PRC1 initiates Polycomb recruitment in X chromosome inactivation. Science 2018; 356:1081-1084. [PMID: 28596365 DOI: 10.1126/science.aal2512] [Citation(s) in RCA: 169] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 05/12/2017] [Indexed: 12/21/2022]
Abstract
Recruitment of the Polycomb repressive complexes PRC1 and PRC2 by Xist RNA is an important paradigm for chromatin regulation by long noncoding RNAs. Here, we show that the noncanonical Polycomb group RING finger 3/5 (PCGF3/5)-PRC1 complex initiates recruitment of both PRC1 and PRC2 in response to Xist RNA expression. PCGF3/5-PRC1-mediated ubiquitylation of histone H2A signals recruitment of other noncanonical PRC1 complexes and of PRC2, the latter leading to deposition of histone H3 lysine 27 methylation chromosome-wide. Pcgf3/5 gene knockout results in female-specific embryo lethality and abrogates Xist-mediated gene repression, highlighting a key role for Polycomb in Xist-dependent chromosome silencing. Our findings overturn existing models for Polycomb recruitment by Xist RNA and establish precedence for H2AK119u1 in initiating Polycomb domain formation in a physiological context.
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Affiliation(s)
- Mafalda Almeida
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Greta Pintacuda
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Osamu Masui
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Yoko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Michal Gdula
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Andrea Cerase
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - David Brown
- Chromatin Biology and Transcription, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Arne Mould
- Mammalian Development, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | | | - Manabu Nakayama
- Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba, 292-0818, Japan
| | - Lothar Schermelleh
- Micron Advanced BioImaging Unit, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Tatyana B Nesterova
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Haruhiko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Neil Brockdorff
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
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Martin CM, Cagliero C, Sun Z, Chen D, Jin DJ. Imaging of Transcription and Replication in the Bacterial Chromosome with Multicolor Three-Dimensional Superresolution Structured Illumination Microscopy. Methods Mol Biol 2018; 1837:117-129. [PMID: 30109608 DOI: 10.1007/978-1-4939-8675-0_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Superresolution imaging technology has contributed to our understanding of the subnucleoid organization in E. coli cells. Multicolor superresolution images revealing "bacterial nucleolus-like structure or organization," "nucleolus-like compartmentalization of the transcription factories," and "spatial segregation of the transcription and replication machineries" have enhanced our understanding of the dynamic landscape of the bacterial chromatin. This chapter provides a brief introduction into multicolor three-dimensional superresolution structured illumination microscopy (3D-SIM) used to study the spatial organization of the transcription machinery and its spatial relationship with replisomes from a microbiological research perspective. In addition to a detailed protocol, practical considerations are discussed in relation to (1) sampling and treatment of cells containing fluorescent fusion proteins, (2) imaging the transcription and replication machineries at single-cell levels, (3) performing imaging experiments to capture the spatial organization of the transcription machinery and the nucleoid, and (4) image acquisition and analysis.
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Affiliation(s)
- Carmen Mata Martin
- Transcription Control Section, RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD, USA
| | - Cedric Cagliero
- Transcription Control Section, RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD, USA.,Jecho Laboratories Inc., Frederick, MD, USA
| | - Zhe Sun
- Transcription Control Section, RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD, USA
| | - De Chen
- Ras Initiative, Frederick National Laboratory for Cancer Research (FNLCR), Leidos Biomedical Research, Inc., Frederick, MD, USA
| | - Ding Jun Jin
- Transcription Control Section, RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD, USA.
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44
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Steube A, Schenk T, Tretyakov A, Saluz HP. High-intensity UV laser ChIP-seq for the study of protein-DNA interactions in living cells. Nat Commun 2017; 8:1303. [PMID: 29101361 PMCID: PMC5670203 DOI: 10.1038/s41467-017-01251-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 08/31/2017] [Indexed: 01/10/2023] Open
Abstract
Genome-wide mapping of transcription factor binding is generally performed by chemical protein–DNA crosslinking, followed by chromatin immunoprecipitation and deep sequencing (ChIP-seq). Here we present the ChIP-seq technique based on photochemical crosslinking of protein–DNA interactions by high-intensity ultraviolet (UV) laser irradiation in living mammalian cells (UV-ChIP-seq). UV laser irradiation induces an efficient and instant formation of covalent “zero-length” crosslinks exclusively between nucleic acids and proteins that are in immediate contact, thus resulting in a “snapshot” of direct protein–DNA interactions in their natural environment. Here we show that UV-ChIP-seq, applied for genome-wide profiling of the sequence-specific transcriptional repressor B-cell lymphoma 6 (BCL6) in human diffuse large B-cell lymphoma (DLBCL) cells, produces sensitive and precise protein–DNA binding profiles, highly enriched with canonical BCL6 DNA sequence motifs. Using this technique, we also found numerous previously undetectable direct BCL6 binding sites, particularly in condensed, inaccessible areas of chromatin. Chromatin immunoprecipitation followed by DNA sequencing (ChIP-seq) can map transcription factor binding to a given genome. Here, Steube and colleagues devise a ChIP-seq technique based on photochemical crosslinking by high-intensity ultraviolet laser irradiation, and describe its utility.
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Affiliation(s)
- Arndt Steube
- Department of Cell and Molecular Biology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, 07745, Germany. .,Department of Internal Medicine IV, Jena University Hospital, Friedrich Schiller University, Jena, 07747, Germany. .,Friedrich Schiller University, Jena, 07737, Germany.
| | - Tino Schenk
- Friedrich Schiller University, Jena, 07737, Germany. .,Department of Hematology and Medical Oncology, Clinic of Internal Medicine II, Jena University Hospital, Jena, 07747, Germany. .,Institute of Molecular Cell Biology, Center for Molecular Biomedicine Jena (CMB), Jena University Hospital, Jena, 07745, Germany.
| | - Alexander Tretyakov
- Department of Cell and Molecular Biology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, 07745, Germany
| | - Hans Peter Saluz
- Department of Cell and Molecular Biology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, 07745, Germany. .,Friedrich Schiller University, Jena, 07737, Germany.
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45
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Festuccia N, Gonzalez I, Owens N, Navarro P. Mitotic bookmarking in development and stem cells. Development 2017; 144:3633-3645. [DOI: 10.1242/dev.146522] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The changes imposed on the nucleus, chromatin and its regulators during mitosis lead to the dismantlement of most gene regulatory processes. However, an increasing number of transcriptional regulators are being identified as capable of binding their genomic targets during mitosis. These so-called ‘mitotic bookmarking factors’ encompass transcription factors and chromatin modifiers that are believed to convey gene regulatory information from mother to daughter cells. In this Primer, we review mitotic bookmarking processes in development and stem cells and discuss the interest and potential importance of this concept with regard to epigenetic regulation and cell fate transitions involving cellular proliferation.
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Affiliation(s)
- Nicola Festuccia
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| | - Inma Gonzalez
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| | - Nick Owens
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| | - Pablo Navarro
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
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46
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Time-resolved analysis of DNA-protein interactions in living cells by UV laser pulses. Sci Rep 2017; 7:11725. [PMID: 28916762 PMCID: PMC5601431 DOI: 10.1038/s41598-017-12010-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 08/30/2017] [Indexed: 11/08/2022] Open
Abstract
Interactions between DNA and proteins are mainly studied through chemical procedures involving bi-functional reagents, mostly formaldehyde. Chromatin immunoprecipitation is used to identify the binding between transcription factors (TFs) and chromatin, and to evaluate the occurrence and impact of histone/DNA modifications. The current bottleneck in probing DNA-protein interactions using these approaches is caused by the fact that chemical crosslinkers do not discriminate direct and indirect bindings or short-lived chromatin occupancy. Here, we describe a novel application of UV laser-induced (L-) crosslinking and demonstrate that a combination of chemical and L-crosslinking is able to distinguish between direct and indirect DNA-protein interactions in a small number of living cells. The spatial and temporal dynamics of TF bindings to chromatin and their role in gene expression regulation may thus be assessed. The combination of chemical and L-crosslinking offers an exciting and unprecedented tool for biomedical applications.
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Loffreda A, Jacchetti E, Antunes S, Rainone P, Daniele T, Morisaki T, Bianchi ME, Tacchetti C, Mazza D. Live-cell p53 single-molecule binding is modulated by C-terminal acetylation and correlates with transcriptional activity. Nat Commun 2017; 8:313. [PMID: 28827596 PMCID: PMC5567047 DOI: 10.1038/s41467-017-00398-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 06/23/2017] [Indexed: 02/07/2023] Open
Abstract
Live-cell microscopy has highlighted that transcription factors bind transiently to chromatin but it is not clear if the duration of these binding interactions can be modulated in response to an activation stimulus, and if such modulation can be controlled by post-translational modifications of the transcription factor. We address this question for the tumor suppressor p53 by combining live-cell single-molecule microscopy and single cell in situ measurements of transcription and we show that p53-binding kinetics are modulated following genotoxic stress. The modulation of p53 residence times on chromatin requires C-terminal acetylation—a classical mark for transcriptionally active p53—and correlates with the induction of transcription of target genes such as CDKN1a. We propose a model in which the modification state of the transcription factor determines the coupling between transcription factor abundance and transcriptional activity by tuning the transcription factor residence time on target sites. Both transcription binding kinetics and post-translational modifications of transcription factors are thought to play a role in the modulation of transcription. Here the authors use single-molecule tracking to directly demonstrate that p53 acetylation modulates promoter residence time and transcriptional activity.
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Affiliation(s)
- Alessia Loffreda
- Istituto Scientifico Ospedale San Raffaele, Centro di Imaging Sperimentale, Milano, 20132, Italy.,Fondazione CEN, European Center for Nanomedicine, Milano, 20133, Italy
| | - Emanuela Jacchetti
- Istituto Scientifico Ospedale San Raffaele, Centro di Imaging Sperimentale, Milano, 20132, Italy.,Dipartimento di Chimica, Materiali e Ingegneria Chimica "G.Natta". Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133, Italy
| | - Sofia Antunes
- Istituto Scientifico Ospedale San Raffaele, Centro di Imaging Sperimentale, Milano, 20132, Italy
| | - Paolo Rainone
- Istituto Scientifico Ospedale San Raffaele, Centro di Imaging Sperimentale, Milano, 20132, Italy.,Institute of Molecular Bioimaging and Physiology, National Researches Council, Segrate, 20090, (MI), Italy
| | - Tiziana Daniele
- Istituto Scientifico Ospedale San Raffaele, Centro di Imaging Sperimentale, Milano, 20132, Italy
| | - Tatsuya Morisaki
- Fluorescence Imaging Group, National Cancer Institute, NIH, Bethesda, Maryland, 20892, USA.,Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Marco E Bianchi
- Istituto Scientifico Ospedale San Raffaele, Chromatin Dynamics Unit, Milano, 20132, Italy.,Università Vita-Salute San Raffaele, Milano, 20132, Italy
| | - Carlo Tacchetti
- Istituto Scientifico Ospedale San Raffaele, Centro di Imaging Sperimentale, Milano, 20132, Italy. .,Università Vita-Salute San Raffaele, Milano, 20132, Italy.
| | - Davide Mazza
- Istituto Scientifico Ospedale San Raffaele, Centro di Imaging Sperimentale, Milano, 20132, Italy. .,Fondazione CEN, European Center for Nanomedicine, Milano, 20133, Italy.
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Denker A, de Laat W. The second decade of 3C technologies: detailed insights into nuclear organization. Genes Dev 2017; 30:1357-82. [PMID: 27340173 PMCID: PMC4926860 DOI: 10.1101/gad.281964.116] [Citation(s) in RCA: 225] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The relevance of three-dimensional (3D) genome organization for transcriptional regulation and thereby for cellular fate at large is now widely accepted. Our understanding of the fascinating architecture underlying this function is based on microscopy studies as well as the chromosome conformation capture (3C) methods, which entered the stage at the beginning of the millennium. The first decade of 3C methods rendered unprecedented insights into genome topology. Here, we provide an update of developments and discoveries made over the more recent years. As we discuss, established and newly developed experimental and computational methods enabled identification of novel, functionally important chromosome structures. Regulatory and architectural chromatin loops throughout the genome are being cataloged and compared between cell types, revealing tissue invariant and developmentally dynamic loops. Architectural proteins shaping the genome were disclosed, and their mode of action is being uncovered. We explain how more detailed insights into the 3D genome increase our understanding of transcriptional regulation in development and misregulation in disease. Finally, to help researchers in choosing the approach best tailored for their specific research question, we explain the differences and commonalities between the various 3C-derived methods.
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Affiliation(s)
- Annette Denker
- Hubrecht Institute-Koninklijke Nederlandse Akademie van Wetenschappen (KNAW) and University Medical Center Utrecht, 3584CT Utrecht, the Netherlands
| | - Wouter de Laat
- Hubrecht Institute-Koninklijke Nederlandse Akademie van Wetenschappen (KNAW) and University Medical Center Utrecht, 3584CT Utrecht, the Netherlands
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Kubik S, Bruzzone MJ, Shore D. Establishing nucleosome architecture and stability at promoters: Roles of pioneer transcription factors and the RSC chromatin remodeler. Bioessays 2017; 39. [PMID: 28345796 DOI: 10.1002/bies.201600237] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Improvements in deep sequencing, together with methods to rapidly deplete essential transcription factors (TFs) and chromatin remodelers, have recently led to a more detailed picture of promoter nucleosome architecture in yeast and its relationship to transcriptional regulation. These studies revealed that ∼40% of all budding yeast protein-coding genes possess a unique promoter structure, where we propose that an unusually unstable nucleosome forms immediately upstream of the transcription start site (TSS). This "fragile" nucleosome (FN) promoter architecture relies on the combined action of the essential RSC (Remodels Structure of Chromatin) nucleosome remodeler and pioneer transcription factors (PTFs). FNs are associated with genes whose expression is high, coupled to cell growth, and characterized by low cell-to-cell variability (noise), suggesting that they may promote these features. Recent studies in metazoans suggest that the presence of dynamic nucleosomes upstream of the TSS at highly expressed genes may be conserved throughout evolution.
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Affiliation(s)
- Slawomir Kubik
- Department of Molecular Biology and Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland
| | - Maria Jessica Bruzzone
- Department of Molecular Biology and Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland
| | - David Shore
- Department of Molecular Biology and Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland
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50
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Translation complex profile sequencing to study the in vivo dynamics of mRNA–ribosome interactions during translation initiation, elongation and termination. Nat Protoc 2017; 12:697-731. [DOI: 10.1038/nprot.2016.189] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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