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Foret MK, Orciani C, Welikovitch LA, Huang C, Cuello AC, Do Carmo S. Early oxidative stress and DNA damage in Aβ-burdened hippocampal neurons in an Alzheimer's-like transgenic rat model. Commun Biol 2024; 7:861. [PMID: 39004677 PMCID: PMC11247100 DOI: 10.1038/s42003-024-06552-4] [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: 12/06/2023] [Accepted: 07/04/2024] [Indexed: 07/16/2024] Open
Abstract
Oxidative stress is a key contributor to AD pathology. However, the earliest role of pre-plaque neuronal oxidative stress, remains elusive. Using laser microdissected hippocampal neurons extracted from McGill-R-Thy1-APP transgenic rats we found that intraneuronal amyloid beta (iAβ)-burdened neurons had increased expression of genes related to oxidative stress and DNA damage responses including Ercc2, Fancc, Sod2, Gsr, and Idh1. DNA damage was further evidenced by increased neuronal levels of XPD (Ercc2) and γH2AX foci, indicative of DNA double stranded breaks (DSBs), and by increased expression of Ercc6, Rad51, and Fen1, and decreased Sirt6 in hippocampal homogenates. We also found increased expression of synaptic plasticity genes (Grin2b (NR2B), CamkIIα, Bdnf, c-fos, and Homer1A) and increased protein levels of TOP2β. Our findings indicate that early accumulation of iAβ, prior to Aβ plaques, is accompanied by incipient oxidative stress and DSBs that may arise directly from oxidative stress or from maladaptive synaptic plasticity.
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Affiliation(s)
- Morgan K Foret
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Chiara Orciani
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | | | - Chunwei Huang
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada.
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada.
- Department of Pharmacology, Oxford University, Oxford, UK.
| | - Sonia Do Carmo
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada.
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2
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Maclay T, Whalen J, Johnson M, Freudenreich CH. The DNA Replication Checkpoint Targets the Kinetochore for Relocation of Collapsed Forks to the Nuclear Periphery. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.17.599319. [PMID: 38948692 PMCID: PMC11212917 DOI: 10.1101/2024.06.17.599319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Hairpin forming expanded CAG/CTG repeats pose significant challenges to DNA replication which can lead to replication fork collapse. Long CAG/CTG repeat tracts relocate to the nuclear pore complex to maintain their integrity. Forks impeded by DNA structures are known to activate the DNA damage checkpoint, thus we asked whether checkpoint proteins play a role in relocation of collapsed forks to the nuclear periphery in S. cerevisiae . We show that relocation of a (CAG/CTG) 130 tract is dependent on activation of the Mrc1/Rad53 replication checkpoint. Further, checkpoint-mediated phosphorylation of the kinetochore protein Cep3 is required for relocation, implicating detachment of the centromere from the spindle pole body. Activation of this pathway leads to DNA damage-induced microtubule recruitment to the repeat. These data suggest a role for the DNA replication checkpoint in facilitating movement of collapsed replication forks to the nuclear periphery by centromere release and microtubule-directed motion. Highlights The DNA replication checkpoint initiates relocation of a structure-forming CAG repeat tract to the nuclear pore complex (NPC)The importance of Mrc1 (hClaspin) implicates fork uncoupling as the initial checkpoint signalPhosphorylation of the Cep3 kinetochore protein by Dun1 kinase allows for centromere release, which is critical for collapsed fork repositioningDamage-inducible nuclear microtubules (DIMs) colocalize with the repeat locus and are required for relocation to the NPCEstablishes a new role for the DNA replication and DNA damage checkpoint response to trigger repositioning of collapsed forks within the nucleus.
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3
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Siler J, Guo N, Liu Z, Qin Y, Bi X. γH2A/γH2AX Mediates DNA Damage-Specific Control of Checkpoint Signaling in Saccharomyces cerevisiae. Int J Mol Sci 2024; 25:2462. [PMID: 38473708 DOI: 10.3390/ijms25052462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 02/13/2024] [Accepted: 02/16/2024] [Indexed: 03/14/2024] Open
Abstract
DNA lesions trigger DNA damage checkpoint (DDC) signaling which arrests cell cycle progression and promotes DNA damage repair. In Saccharomyces cerevisiae, phosphorylation of histone H2A (γH2A, equivalent to γH2AX in mammals) is an early chromatin mark induced by DNA damage that is recognized by a group of DDC and DNA repair factors. We find that γH2A negatively regulates the G2/M checkpoint in response to the genotoxin camptothecin, which is a DNA topoisomerase I poison. γH2A also suppresses DDC signaling induced by the DNA alkylating agent methyl methanesulfonate. These results differ from prior findings, which demonstrate positive or no roles of γH2A in DDC in response to other DNA damaging agents such as phleomycin and ionizing radiation, which suggest that γH2A has DNA damage-specific effects on DDC signaling. We also find evidence supporting the notion that γH2A regulates DDC signaling by mediating the competitive recruitment of the DDC mediator Rad9 and the DNA repair factor Rtt107 to DNA lesions. We propose that γH2A/γH2AX serves to create a dynamic balance between DDC and DNA repair that is influenced by the nature of DNA damage.
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Affiliation(s)
- Jasmine Siler
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Na Guo
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
- College of Food Science and Engineering, Jilin University, Changchun 130012, China
| | - Zhengfeng Liu
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Yuhua Qin
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Xin Bi
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
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4
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Atkinson J, Bezak E, Le H, Kempson I. DNA Double Strand Break and Response Fluorescent Assays: Choices and Interpretation. Int J Mol Sci 2024; 25:2227. [PMID: 38396904 PMCID: PMC10889524 DOI: 10.3390/ijms25042227] [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: 12/22/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
Accurately characterizing DNA double-stranded breaks (DSBs) and understanding the DNA damage response (DDR) is crucial for assessing cellular genotoxicity, maintaining genomic integrity, and advancing gene editing technologies. Immunofluorescence-based techniques have proven to be invaluable for quantifying and visualizing DSB repair, providing valuable insights into cellular repair processes. However, the selection of appropriate markers for analysis can be challenging due to the intricate nature of DSB repair mechanisms, often leading to ambiguous interpretations. This comprehensively summarizes the significance of immunofluorescence-based techniques, with their capacity for spatiotemporal visualization, in elucidating complex DDR processes. By evaluating the strengths and limitations of different markers, we identify where they are most relevant chronologically from DSB detection to repair, better contextualizing what each assay represents at a molecular level. This is valuable for identifying biases associated with each assay and facilitates accurate data interpretation. This review aims to improve the precision of DSB quantification, deepen the understanding of DDR processes, assay biases, and pathway choices, and provide practical guidance on marker selection. Each assay offers a unique perspective of the underlying processes, underscoring the need to select markers that are best suited to specific research objectives.
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Affiliation(s)
- Jake Atkinson
- Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia;
| | - Eva Bezak
- UniSA Allied Health and Human Performance, University of South Australia, Adelaide, SA 5095, Australia; (E.B.)
- Department of Physics, University of Adelaide, North Terrace, Adelaide, SA 5005, Australia
| | - Hien Le
- UniSA Allied Health and Human Performance, University of South Australia, Adelaide, SA 5095, Australia; (E.B.)
- Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, SA 5000, Australia
| | - Ivan Kempson
- Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia;
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5
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García Fernández F, Huet S, Miné-Hattab J. Multi-Scale Imaging of the Dynamic Organization of Chromatin. Int J Mol Sci 2023; 24:15975. [PMID: 37958958 PMCID: PMC10649806 DOI: 10.3390/ijms242115975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/27/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023] Open
Abstract
Chromatin is now regarded as a heterogeneous and dynamic structure occupying a non-random position within the cell nucleus, where it plays a key role in regulating various functions of the genome. This current view of chromatin has emerged thanks to high spatiotemporal resolution imaging, among other new technologies developed in the last decade. In addition to challenging early assumptions of chromatin being regular and static, high spatiotemporal resolution imaging made it possible to visualize and characterize different chromatin structures such as clutches, domains and compartments. More specifically, super-resolution microscopy facilitates the study of different cellular processes at a nucleosome scale, providing a multi-scale view of chromatin behavior within the nucleus in different environments. In this review, we describe recent imaging techniques to study the dynamic organization of chromatin at high spatiotemporal resolution. We also discuss recent findings, elucidated by these techniques, on the chromatin landscape during different cellular processes, with an emphasis on the DNA damage response.
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Affiliation(s)
- Fabiola García Fernández
- Laboratory of Computational and Quantitative Biology, CNRS, Institut de Biologie Paris-Seine, Sorbonne Université, 75005 Paris, France;
| | - Sébastien Huet
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes)-UMR 6290, BIOSIT-UMS 3480, 35000 Rennes, France;
- Institut Universitaire de France, 75231 Paris, France
| | - Judith Miné-Hattab
- Laboratory of Computational and Quantitative Biology, CNRS, Institut de Biologie Paris-Seine, Sorbonne Université, 75005 Paris, France;
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6
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Yates LA, Zhang X. Phosphoregulation of the checkpoint kinase Mec1 ATR. DNA Repair (Amst) 2023; 129:103543. [PMID: 37480741 DOI: 10.1016/j.dnarep.2023.103543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/14/2023] [Accepted: 07/15/2023] [Indexed: 07/24/2023]
Abstract
Yeast Mec1, and its mammalian ortholog, Ataxia-Telangiectasia and Rad3-related, are giant protein kinases central to replication stress and double strand DNA break repair. Mec1ATR, in complex with Ddc2ATRIP, is a 'sensor' of single stranded DNA, and phosphorylates numerous cell cycle and DNA repair factors to enforce cell cycle arrest and facilitate repair. Over the last several years, new techniques - particularly in structural biology - have provided molecular mechanisms for Mec1ATR function. It is becoming increasingly clear how post-translational modification of Mec1ATR and its interaction partners modulates the DNA damage checkpoint. In this review, we summarise the most recent work unravelling Mec1ATR function in the DNA damage checkpoint and provide a molecular context for its regulation by phosphorylation.
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Affiliation(s)
- Luke A Yates
- Section of Structural, Department of Infectious Disease, Sir Alexander Fleming Building, Imperial College London, SW7 2AZ, UK; DNA processing machines laboratory, Francis Crick Institute, London NW1 1AT, UK.
| | - Xiaodong Zhang
- Section of Structural, Department of Infectious Disease, Sir Alexander Fleming Building, Imperial College London, SW7 2AZ, UK; DNA processing machines laboratory, Francis Crick Institute, London NW1 1AT, UK.
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Schaffer ED, Beerman I, de Cabo R, Brosh RM. Frontiers in aging special issue: DNA repair and interventions in aging perspective on "loss of epigenetic information as a cause of mammalian aging". FRONTIERS IN AGING 2023; 4:1199596. [PMID: 37475956 PMCID: PMC10354253 DOI: 10.3389/fragi.2023.1199596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/23/2023] [Indexed: 07/22/2023]
Abstract
The recently published article in Cell by the Sinclair lab and collaborators entitled "Loss of Epigenetic Information as a Cause of Mammalian Aging" [1] implicates heritable changes in gene expression as the basis for aging, a postulate consistent with the emerging information theory of aging. Sinclair's group and colleagues induced epigenetic changes, i.e., DNA and histone modifications, via double-strand breaks (DSBs) catalyzed by the I-Pol endonuclease at specific genomic loci. The genomic DNA breaks, introduced without inducing insertion or deletion mutations (indels) in a mouse model, were targeted to 19 non-coding regions and one region in ribosomal DNA (rDNA), the latter shown to not have a significant effect on the function or transcription of rDNA [1]. With that experimental model in place, the authors present experimental evidence supporting a model that epigenetic changes drive aging via this inducible DNA break mechanism. After demonstrating the phenotypic alterations of this accelerated aging, they attempt to reverse selective phenotypes by resetting the altered epigenetic landscape. Establishing a causal relationship between epigenetic changes and aging, and how this connection might be manipulated to overturn cellular features of aging, is provocative and merits further study.
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8
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Rinaldi C, Pizzul P, Casari E, Mangiagalli M, Tisi R, Longhese MP. The Ku complex promotes DNA end-bridging and this function is antagonized by Tel1/ATM kinase. Nucleic Acids Res 2023; 51:1783-1802. [PMID: 36762474 PMCID: PMC9976877 DOI: 10.1093/nar/gkad062] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 01/18/2023] [Accepted: 01/20/2023] [Indexed: 02/11/2023] Open
Abstract
DNA double-strand breaks (DSBs) can be repaired by either homologous recombination (HR) or non-homologous end-joining (NHEJ). NHEJ is induced by the binding to DSBs of the Ku70-Ku80 heterodimer, which acts as a hub for the recruitment of downstream NHEJ components. An important issue in DSB repair is the maintenance of the DSB ends in close proximity, a function that in yeast involves the MRX complex and Sae2. Here, we provide evidence that Ku contributes to keep the DNA ends tethered to each other. The ku70-C85Y mutation, which increases Ku affinity for DNA and its persistence very close to the DSB ends, enhances DSB end-tethering and suppresses the end-tethering defect of sae2Δ cells. Impairing histone removal around DSBs either by eliminating Tel1 kinase activity or nucleosome remodelers enhances Ku persistence at DSBs and DSB bridging, suggesting that Tel1 antagonizes the Ku function in supporting end-tethering by promoting nucleosome removal and possibly Ku sliding inwards. As Ku provides a block to DSB resection, this Tel1 function can be important to regulate the mode by which DSBs are repaired.
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Affiliation(s)
- Carlo Rinaldi
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - Paolo Pizzul
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - Erika Casari
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - Marco Mangiagalli
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - Renata Tisi
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - Maria Pia Longhese
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
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9
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Frigerio C, Di Nisio E, Galli M, Colombo CV, Negri R, Clerici M. The Chromatin Landscape around DNA Double-Strand Breaks in Yeast and Its Influence on DNA Repair Pathway Choice. Int J Mol Sci 2023; 24:ijms24043248. [PMID: 36834658 PMCID: PMC9967470 DOI: 10.3390/ijms24043248] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 01/21/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023] Open
Abstract
DNA double-strand breaks (DSBs) are harmful DNA lesions, which elicit catastrophic consequences for genome stability if not properly repaired. DSBs can be repaired by either non-homologous end joining (NHEJ) or homologous recombination (HR). The choice between these two pathways depends on which proteins bind to the DSB ends and how their action is regulated. NHEJ initiates with the binding of the Ku complex to the DNA ends, while HR is initiated by the nucleolytic degradation of the 5'-ended DNA strands, which requires several DNA nucleases/helicases and generates single-stranded DNA overhangs. DSB repair occurs within a precisely organized chromatin environment, where the DNA is wrapped around histone octamers to form the nucleosomes. Nucleosomes impose a barrier to the DNA end processing and repair machinery. Chromatin organization around a DSB is modified to allow proper DSB repair either by the removal of entire nucleosomes, thanks to the action of chromatin remodeling factors, or by post-translational modifications of histones, thus increasing chromatin flexibility and the accessibility of repair enzymes to the DNA. Here, we review histone post-translational modifications occurring around a DSB in the yeast Saccharomyces cerevisiae and their role in DSB repair, with particular attention to DSB repair pathway choice.
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Affiliation(s)
- Chiara Frigerio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Elena Di Nisio
- Department of Biology and Biotechnologies “C. Darwin”, Sapienza University of Rome, 00185 Rome, Italy
| | - Michela Galli
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Chiara Vittoria Colombo
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Rodolfo Negri
- Department of Biology and Biotechnologies “C. Darwin”, Sapienza University of Rome, 00185 Rome, Italy
- Institute of Molecular Biology and Pathology (IBPM), National Research Council (CNR) of Italy, 00185 Rome, Italy
- Correspondence: (R.N.); (M.C.)
| | - Michela Clerici
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
- Correspondence: (R.N.); (M.C.)
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10
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Kar FM, Vogel C, Hochwagen A. Meiotic DNA breaks activate a streamlined phospho-signaling response that largely avoids protein-level changes. Life Sci Alliance 2022; 5:e202201454. [PMID: 36271494 PMCID: PMC9438802 DOI: 10.26508/lsa.202201454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 08/15/2022] [Accepted: 08/19/2022] [Indexed: 11/24/2022] Open
Abstract
Meiotic cells introduce a numerous programmed DNA breaks into their genome to stimulate meiotic recombination and ensure controlled chromosome inheritance and fertility. A checkpoint network involving key kinases and phosphatases coordinates the repair of these DNA breaks, but the precise phosphorylation targets remain poorly understood. It is also unknown whether meiotic DNA breaks change gene expression akin to the canonical DNA-damage response. To address these questions, we analyzed the meiotic DNA break response in Saccharomyces cerevisiae using multiple systems-level approaches. We identified 332 DNA break-dependent phosphorylation sites, vastly expanding the number of known events during meiotic prophase. Less than half of these events occurred in recognition motifs for the known meiotic checkpoint kinases Mec1 (ATR), Tel1 (ATM), and Mek1 (CHK2), suggesting that additional kinases contribute to the meiotic DNA-break response. We detected a clear transcriptional program but detected only very few changes in protein levels. We attribute this dichotomy to a decrease in transcript levels after meiotic entry that dampens the effects of break-induced transcription sufficiently to cause only minimal changes in the meiotic proteome.
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Affiliation(s)
- Funda M Kar
- Department of Biology, New York University, New York City, NY, USA
| | - Christine Vogel
- Department of Biology, New York University, New York City, NY, USA
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11
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García Fernández F, Almayrac E, Carré Simon À, Batrin R, Khalil Y, Boissac M, Fabre E. Global chromatin mobility induced by a DSB is dictated by chromosomal conformation and defines the HR outcome. eLife 2022; 11:78015. [PMID: 36125964 PMCID: PMC9489209 DOI: 10.7554/elife.78015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 09/08/2022] [Indexed: 12/16/2022] Open
Abstract
Repair of DNA double-strand breaks (DSBs) is crucial for genome integrity. A conserved response to DSBs is an increase in chromatin mobility that can be local, at the site of the DSB, or global, at undamaged regions of the genome. Here, we address the function of global chromatin mobility during homologous recombination (HR) of a single, targeted, controlled DSB. We set up a system that tracks HR in vivo over time and show that two types of DSB-induced global chromatin mobility are involved in HR, depending on the position of the DSB. Close to the centromere, a DSB induces global mobility that depends solely on H2A(X) phosphorylation and accelerates repair kinetics, but is not essential. In contrast, the global mobility induced by a DSB away from the centromere becomes essential for HR repair and is triggered by homology search through a mechanism that depends on H2A(X) phosphorylation, checkpoint progression, and Rad51. Our data demonstrate that global mobility is governed by chromosomal conformation and differentially coordinates repair by HR.
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Affiliation(s)
| | - Etienne Almayrac
- Université de Paris, IRSL, INSERM, U944, CNRS, UMR7212, Paris, France
| | - Ànnia Carré Simon
- Université de Paris, IRSL, INSERM, U944, CNRS, UMR7212, Paris, France
| | - Renaud Batrin
- Université de Paris, IRSL, INSERM, U944, CNRS, UMR7212, Paris, France
| | - Yasmine Khalil
- Université de Paris, IRSL, INSERM, U944, CNRS, UMR7212, Paris, France
| | - Michel Boissac
- Université de Paris, IRSL, INSERM, U944, CNRS, UMR7212, Paris, France
| | - Emmanuelle Fabre
- Université de Paris, IRSL, INSERM, U944, CNRS, UMR7212, Paris, France
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12
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Pizzul P, Casari E, Gnugnoli M, Rinaldi C, Corallo F, Longhese MP. The DNA damage checkpoint: A tale from budding yeast. Front Genet 2022; 13:995163. [PMID: 36186482 PMCID: PMC9520983 DOI: 10.3389/fgene.2022.995163] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 08/30/2022] [Indexed: 11/30/2022] Open
Abstract
Studies performed in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe have led the way in defining the DNA damage checkpoint and in identifying most of the proteins involved in this regulatory network, which turned out to have structural and functional equivalents in humans. Subsequent experiments revealed that the checkpoint is an elaborate signal transduction pathway that has the ability to sense and signal the presence of damaged DNA and transduce this information to influence a multifaceted cellular response that is essential for cancer avoidance. This review focuses on the work that was done in Saccharomyces cerevisiae to articulate the checkpoint concept, to identify its players and the mechanisms of activation and deactivation.
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13
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Babu S, Takeuchi Y, Masai I. Banp regulates DNA damage response and chromosome segregation during the cell cycle in zebrafish retina. eLife 2022; 11:74611. [PMID: 35942692 PMCID: PMC9363121 DOI: 10.7554/elife.74611] [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] [Received: 10/11/2021] [Accepted: 07/05/2022] [Indexed: 11/25/2022] Open
Abstract
Btg3-associated nuclear protein (Banp) was originally identified as a nuclear matrix-associated region (MAR)-binding protein and it functions as a tumor suppressor. At the molecular level, Banp regulates transcription of metabolic genes via a CGCG-containing motif called the Banp motif. However, its physiological roles in embryonic development are unknown. Here, we report that Banp is indispensable for the DNA damage response and chromosome segregation during mitosis. Zebrafish banp mutants show mitotic cell accumulation and apoptosis in developing retina. We found that DNA replication stress and tp53-dependent DNA damage responses were activated to induce apoptosis in banp mutants, suggesting that Banp is required for regulation of DNA replication and DNA damage repair. Furthermore, consistent with mitotic cell accumulation, chromosome segregation was not smoothly processed from prometaphase to anaphase in banp morphants, leading to a prolonged M-phase. Our RNA- and ATAC-sequencing identified 31 candidates for direct Banp target genes that carry the Banp motif. Interestingly, a DNA replication fork regulator, wrnip1, and two chromosome segregation regulators, cenpt and ncapg, are included in this list. Thus, Banp directly regulates transcription of wrnip1 for recovery from DNA replication stress, and cenpt and ncapg for chromosome segregation during mitosis. Our findings provide the first in vivo evidence that Banp is required for cell-cycle progression and cell survival by regulating DNA damage responses and chromosome segregation during mitosis. In order for a cell to divide, it must progress through a series of carefully controlled steps known as the cell cycle. First, the cell replicates its DNA and both copies get segregated to opposite ends. The cell then splits into two and each new cell receives a copy of the duplicated genetic material. If any of the stages in the cell cycle become disrupted or mis-regulated this can lead to uncontrolled divisions that may result in cancer. Researchers have often used a structure within the eye known as the retina to study the cell cycle in zebrafish and other animals as cells in the retina rapidly divide in a highly controlled manner. A protein called Banp is known to help stop tumors from growing in humans and mice, but its normal role in the body, particularly the cell cycle, has remained unclear. To investigate, Babu et al. studied the retina of mutant zebrafish that were unable to make the Banp protein. The experiments revealed that two stress responses indicating DNA damage or defects in copying DNA were active in the retinal cells of the mutant zebrafish. This suggested that Banp allows cell to progress through the cell cycle by repairing any DNA damage that may arise during replication. Banp does this by activating the gene for another protein called Wrnip1. Babu et al. also found that Banp helps segregate the two copies of DNA during cell division by promoting the activation of two other proteins called Cenpt and Ncapg. Further experiments identified 31 genes that were directly regulated by Banp. These findings demonstrate that Banp is required for zebrafish cells to be able to accurately copy their DNA and divide in to two new cells. In the future, the work of Babu et al. will provide a useful resource to investigate how tumors grow and spread around the body, and may contribute to the development of new treatments for cancer.
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Affiliation(s)
- Swathy Babu
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Yuki Takeuchi
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Ichiro Masai
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
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14
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Scherzer M, Giordano F, Ferran MS, Ström L. Recruitment of Scc2/4 to double-strand breaks depends on γH2A and DNA end resection. Life Sci Alliance 2022; 5:e202101244. [PMID: 35086935 PMCID: PMC8807874 DOI: 10.26508/lsa.202101244] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 01/13/2022] [Accepted: 01/14/2022] [Indexed: 12/15/2022] Open
Abstract
Homologous recombination enables cells to overcome the threat of DNA double-strand breaks (DSBs), allowing for repair without the loss of genetic information. Central to the homologous recombination repair process is the de novo loading of cohesin around a DSB by its loader complex Scc2/4. Although cohesin's DSB accumulation has been explored in numerous studies, the prerequisites for Scc2/4 recruitment during the repair process are still elusive. To address this question, we combine chromatin immunoprecipitation-qPCR with a site-specific DSB in vivo, in Saccharomyces cerevisiae We find that Scc2 DSB recruitment relies on γH2A and Tel1, but as opposed to cohesin, not on Mec1. We further show that the binding of Scc2, which emanates from the break site, depends on and coincides with DNA end resection. Absence of chromatin remodeling at the DSB affects Scc2 binding and DNA end resection to a comparable degree, further indicating the latter to be a major driver for Scc2 recruitment. Our results shed light on the intricate DSB repair cascade leading to the recruitment of Scc2/4 and subsequent loading of cohesin.
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Affiliation(s)
- Martin Scherzer
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Fosco Giordano
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Maria Solé Ferran
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Lena Ström
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
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15
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Xin Y, Wang J, Wu Y, Li Q, Dong M, Liu C, He Q, Wang R, Wang D, Jiang S, Xiao W, Tian Y, Zhang W. Identification of Nanog as a novel inhibitor of Rad51. Cell Death Dis 2022; 13:193. [PMID: 35220392 PMCID: PMC8882189 DOI: 10.1038/s41419-022-04644-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 01/12/2022] [Accepted: 02/01/2022] [Indexed: 11/09/2022]
Abstract
AbstractTo develop inhibitors targeting DNA damage repair pathways is important to improve the effectiveness of chemo- and radiotherapy for cancer patients. Rad51 mediates homologous recombination (HR) repair of DNA damages. It is widely overexpressed in human cancers and overwhelms chemo- and radiotherapy-generated DNA damages through enhancing HR repair signaling, preventing damage-caused cancer cell death. Therefore, to identify inhibitors of Rad51 is important to achieve effective treatment of cancers. Transcription factor Nanog is a core regulator of embryonic stem (ES) cells for its indispensable role in stemness maintenance. In this study, we identified Nanog as a novel inhibitor of Rad51. It interacts with Rad51 and inhibits Rad51-mediated HR repair of DNA damage through its C/CD2 domain. Moreover, Rad51 inhibition can be achieved by nanoscale material- or cell-penetrating peptide (CPP)-mediated direct delivery of Nanog-C/CD2 peptides into somatic cancer cells. Furthermore, we revealed that Nanog suppresses the binding of Rad51 to single-stranded DNAs to stall the HR repair signaling. This study provides explanation for the high γH2AX level in unperturbed ES cells and early embryos, and suggests Nanog-C/CD2 as a promising drug candidate applied to Rad51-related basic research and therapeutic application studies.
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16
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García Fernández F, Fabre E. The Dynamic Behavior of Chromatin in Response to DNA Double-Strand Breaks. Genes (Basel) 2022; 13:genes13020215. [PMID: 35205260 PMCID: PMC8872016 DOI: 10.3390/genes13020215] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 02/05/2023] Open
Abstract
The primary functions of the eukaryotic nucleus as a site for the storage, retrieval, and replication of information require a highly dynamic chromatin organization, which can be affected by the presence of DNA damage. In response to double-strand breaks (DSBs), the mobility of chromatin at the break site is severely affected and, to a lesser extent, that of other chromosomes. The how and why of such movement has been widely studied over the last two decades, leading to different mechanistic models and proposed potential roles underlying both local and global mobility. Here, we review the state of the knowledge on current issues affecting chromatin mobility upon DSBs, and highlight its role as a crucial step in the DNA damage response (DDR).
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Affiliation(s)
- Fabiola García Fernández
- Institut Curie, CNRS UMR3664, Sorbonne Université, F-75005 Paris, France
- Correspondence: (F.G.F.); (E.F.)
| | - Emmanuelle Fabre
- Génomes Biologie Cellulaire et Thérapeutiques, CNRS UMR7212, INSERM U944, Université de Paris, F-75010 Paris, France
- Correspondence: (F.G.F.); (E.F.)
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17
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Phipps J, Dubrana K. DNA Repair in Space and Time: Safeguarding the Genome with the Cohesin Complex. Genes (Basel) 2022; 13:198. [PMID: 35205243 PMCID: PMC8872453 DOI: 10.3390/genes13020198] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/20/2022] [Accepted: 01/20/2022] [Indexed: 12/04/2022] Open
Abstract
DNA double-strand breaks (DSBs) are a deleterious form of DNA damage, which must be robustly addressed to ensure genome stability. Defective repair can result in chromosome loss, point mutations, loss of heterozygosity or chromosomal rearrangements, which could lead to oncogenesis or cell death. We explore the requirements for the successful repair of DNA DSBs by non-homologous end joining and homology-directed repair (HDR) mechanisms in relation to genome folding and dynamics. On the occurrence of a DSB, local and global chromatin composition and dynamics, as well as 3D genome organization and break localization within the nuclear space, influence how repair proceeds. The cohesin complex is increasingly implicated as a key regulator of the genome, influencing chromatin composition and dynamics, and crucially genome organization through folding chromosomes by an active loop extrusion mechanism, and maintaining sister chromatid cohesion. Here, we consider how this complex is now emerging as a key player in the DNA damage response, influencing repair pathway choice and efficiency.
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Affiliation(s)
| | - Karine Dubrana
- UMR Stabilité Génétique Cellules Souches et Radiations, INSERM, iRCM/IBFJ CEA, Université de Paris and Université Paris-Saclay, F-92265 Fontenay-aux-Roses, France;
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18
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Allen D, Weiss LE, Saguy A, Rosenberg M, Iancu O, Matalon O, Lee C, Beider K, Nagler A, Shechtman Y, Hendel A. High-throughput Imaging of CRISPR- and Recombinant Adeno-associated Virus-induced DNA Damage Response in Human Hematopoietic Stem and Progenitor Cells. CRISPR J 2022; 5:80-94. [PMID: 35049367 PMCID: PMC8892977 DOI: 10.1089/crispr.2021.0128] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
CRISPR-Cas technology has revolutionized gene editing, but concerns remain due to its propensity for off-target interactions. This, combined with genotoxicity related to both CRISPR-Cas9-induced double-strand breaks and transgene delivery, poses a significant liability for clinical genome-editing applications. Current best practice is to optimize genome-editing parameters in preclinical studies. However, quantitative tools that measure off-target interactions and genotoxicity are costly and time-consuming, limiting the practicality of screening large numbers of potential genome-editing reagents and conditions. Here, we show that flow-based imaging facilitates DNA damage characterization of hundreds of human hematopoietic stem and progenitor cells per minute after treatment with CRISPR-Cas9 and recombinant adeno-associated virus serotype 6. With our web-based platform that leverages deep learning for image analysis, we find that greater DNA damage response is observed for guide RNAs with higher genome-editing activity, differentiating even single on-target guide RNAs with different levels of off-target interactions. This work simplifies the characterization and screening process of genome-editing parameters toward enabling safer and more effective gene-therapy applications.
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Affiliation(s)
- Daniel Allen
- Institute of Nanotechnology and Advanced Materials, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Lucien E Weiss
- Department of Biomedical Engineering, Technion, Haifa, Israel.,Department of Engineering Physics, Polytechnique Montreal, Canada
| | - Alon Saguy
- Department of Biomedical Engineering, Technion, Haifa, Israel
| | - Michael Rosenberg
- Institute of Nanotechnology and Advanced Materials, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Ortal Iancu
- Institute of Nanotechnology and Advanced Materials, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Omri Matalon
- Arazi School of Computer Science, Interdisciplinary Center, Herzliya, Israel
| | - Ciaran Lee
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Katia Beider
- Division of Hematology and Bone Marrow Transplantation, Chaim Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel
| | - Arnon Nagler
- Division of Hematology and Bone Marrow Transplantation, Chaim Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yoav Shechtman
- Department of Biomedical Engineering, Technion, Haifa, Israel
| | - Ayal Hendel
- Institute of Nanotechnology and Advanced Materials, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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19
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Mondal A, Bhattacharya A, Singh V, Pandita S, Bacolla A, Pandita RK, Tainer JA, Ramos KS, Pandita TK, Das C. Stress Responses as Master Keys to Epigenomic Changes in Transcriptome and Metabolome for Cancer Etiology and Therapeutics. Mol Cell Biol 2022; 42:e0048321. [PMID: 34748401 PMCID: PMC8773053 DOI: 10.1128/mcb.00483-21] [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] [Indexed: 11/20/2022] Open
Abstract
From initiation through progression, cancer cells are subjected to a magnitude of endogenous and exogenous stresses, which aid in their neoplastic transformation. Exposure to these classes of stress induces imbalance in cellular homeostasis and, in response, cancer cells employ informative adaptive mechanisms to rebalance biochemical processes that facilitate survival and maintain their existence. Different kinds of stress stimuli trigger epigenetic alterations in cancer cells, which leads to changes in their transcriptome and metabolome, ultimately resulting in suppression of growth inhibition or induction of apoptosis. Whether cancer cells show a protective response to stress or succumb to cell death depends on the type of stress and duration of exposure. A thorough understanding of epigenetic and molecular architecture of cancer cell stress response pathways can unveil a plethora of information required to develop novel anticancer therapeutics. The present view highlights current knowledge about alterations in epigenome and transcriptome of cancer cells as a consequence of exposure to different physicochemical stressful stimuli such as reactive oxygen species (ROS), hypoxia, radiation, hyperthermia, genotoxic agents, and nutrient deprivation. Currently, an anticancer treatment scenario involving the imposition of stress to target cancer cells is gaining traction to augment or even replace conventional therapeutic regimens. Therefore, a comprehensive understanding of stress response pathways is crucial for devising and implementing novel therapeutic strategies.
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Affiliation(s)
- Atanu Mondal
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
- Homi Bhaba National Institute, Mumbai, India
| | - Apoorva Bhattacharya
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
| | - Vipin Singh
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
- Homi Bhaba National Institute, Mumbai, India
| | - Shruti Pandita
- Division of Hematology and Medical Oncology, St. Louis University, St. Louis, Missouri, USA
| | - Albino Bacolla
- Department of Molecular and Cellular Oncology, University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA
| | - Raj K. Pandita
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - John A. Tainer
- Department of Molecular and Cellular Oncology, University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA
| | - Kenneth S. Ramos
- Center for Genomics and Precision Medicine, Texas A&M College of Medicine, Houston, Texas, USA
| | - Tej K. Pandita
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
- Center for Genomics and Precision Medicine, Texas A&M College of Medicine, Houston, Texas, USA
| | - Chandrima Das
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
- Homi Bhaba National Institute, Mumbai, India
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20
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3D Genome Organization: Causes and Consequences for DNA Damage and Repair. Genes (Basel) 2021; 13:genes13010007. [PMID: 35052348 PMCID: PMC8775012 DOI: 10.3390/genes13010007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/16/2021] [Accepted: 12/18/2021] [Indexed: 01/02/2023] Open
Abstract
The inability to repair damaged DNA severely compromises the integrity of any organism. In eukaryotes, the DNA damage response (DDR) operates within chromatin, a tightly organized DNA–histone complex in a non-random manner within the nucleus. Chromatin thus orchestrates various cellular processes, including repair. Here, we examine the chromatin landscape before, during, and after the DNA damage, focusing on double strand breaks (DSBs). We study how chromatin is modified during the repair process, not only around the damaged region (in cis), but also genome-wide (in trans). Recent evidence has highlighted a complex landscape in which different chromatin parameters (stiffness, compaction, loops) are transiently modified, defining “codes” for each specific stage of the DDR. We illustrate a novel aspect of DDR where chromatin modifications contribute to the movement of DSB-damaged chromatin, as well as undamaged chromatin, ensuring the mobilization of DSBs, their clustering, and their repair processes.
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21
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DNA Damage-Induced Phosphorylation of Histone H2A at Serine 15 Is Linked to DNA End Resection. Mol Cell Biol 2021; 41:e0005621. [PMID: 34570618 DOI: 10.1128/mcb.00056-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The repair of DNA double-strand breaks (DSBs) occurs in chromatin, and several histone posttranslational modifications have been implicated in the process. Modifications of the histone H2A N-terminal tail have also been linked to DNA damage response, through acetylation or ubiquitination of lysine residues that regulate repair pathway choice. Here, we characterize a new DNA damage-induced phosphorylation on chromatin, at serine 15 of H2A in yeast. We show that this SQ motif functions independently of the classical S129 C-terminal site (γ-H2A) and that mutant-mimicking constitutive phosphorylation increases cell sensitivity to DNA damage. H2AS129ph is induced by Tel1ATM and Mec1ATR, and the loss of Lcd1ATRIP or Mec1 signaling decreases γ-H2A spreading distal to the DSB. In contrast, H2AS15ph is completely dependent on Lcd1ATRIP, indicating that this modification only happens when end resection is engaged. This is supported by an increase in replication protein A (RPA) and a decrease in DNA signal near the DSB in H2A-S15E phosphomimic mutants, indicating higher resection. In mammals, this serine is replaced by a lysine (H2AK15) which undergoes an acetyl-monoubiquityl switch to regulate binding of 53BP1 and resection. This regulation seems functionally conserved with budding yeast H2AS15 and 53BP1-homolog Rad9, using different posttranslational modifications between organisms but achieving the same function.
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22
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Casari E, Gobbini E, Gnugnoli M, Mangiagalli M, Clerici M, Longhese MP. Dpb4 promotes resection of DNA double-strand breaks and checkpoint activation by acting in two different protein complexes. Nat Commun 2021; 12:4750. [PMID: 34362907 PMCID: PMC8346560 DOI: 10.1038/s41467-021-25090-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 07/20/2021] [Indexed: 12/24/2022] Open
Abstract
Budding yeast Dpb4 (POLE3/CHRAC17 in mammals) is a highly conserved histone fold protein that is shared by two protein complexes: the chromatin remodeler ISW2/hCHRAC and the DNA polymerase ε (Pol ε) holoenzyme. In Saccharomyces cerevisiae, Dpb4 forms histone-like dimers with Dls1 in the ISW2 complex and with Dpb3 in the Pol ε complex. Here, we show that Dpb4 plays two functions in sensing and processing DNA double-strand breaks (DSBs). Dpb4 promotes histone removal and DSB resection by interacting with Dls1 to facilitate the association of the Isw2 ATPase to DSBs. Furthermore, it promotes checkpoint activation by interacting with Dpb3 to facilitate the association of the checkpoint protein Rad9 to DSBs. Persistence of both Isw2 and Rad9 at DSBs is enhanced by the A62S mutation that is located in the Dpb4 histone fold domain and increases Dpb4 association at DSBs. Thus, Dpb4 exerts two distinct functions at DSBs depending on its interactors. The histone folding protein Dpb4 forms histone-like dimers within the ISW2 complex and the Pol ε complex in S. cerevisiae. Here the authors reveal insights into two distinct functions that Dpb4 exerts at DSBs depending on its interactors.
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Affiliation(s)
- Erika Casari
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Elisa Gobbini
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Marco Gnugnoli
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Marco Mangiagalli
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Michela Clerici
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Maria Pia Longhese
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy.
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23
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Complex Mechanisms of Antimony Genotoxicity in Budding Yeast Involves Replication and Topoisomerase I-Associated DNA Lesions, Telomere Dysfunction and Inhibition of DNA Repair. Int J Mol Sci 2021; 22:ijms22094510. [PMID: 33925940 PMCID: PMC8123508 DOI: 10.3390/ijms22094510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 11/26/2022] Open
Abstract
Antimony is a toxic metalloid with poorly understood mechanisms of toxicity and uncertain carcinogenic properties. By using a combination of genetic, biochemical and DNA damage assays, we investigated the genotoxic potential of trivalent antimony in the model organism Saccharomyces cerevisiae. We found that low doses of Sb(III) generate various forms of DNA damage including replication and topoisomerase I-dependent DNA lesions as well as oxidative stress and replication-independent DNA breaks accompanied by activation of DNA damage checkpoints and formation of recombination repair centers. At higher concentrations of Sb(III), moderately increased oxidative DNA damage is also observed. Consistently, base excision, DNA damage tolerance and homologous recombination repair pathways contribute to Sb(III) tolerance. In addition, we provided evidence suggesting that Sb(III) causes telomere dysfunction. Finally, we showed that Sb(III) negatively effects repair of double-strand DNA breaks and distorts actin and microtubule cytoskeleton. In sum, our results indicate that Sb(III) exhibits a significant genotoxic activity in budding yeast.
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24
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Kar FM, Hochwagen A. Phospho-Regulation of Meiotic Prophase. Front Cell Dev Biol 2021; 9:667073. [PMID: 33928091 PMCID: PMC8076904 DOI: 10.3389/fcell.2021.667073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 03/22/2021] [Indexed: 12/12/2022] Open
Abstract
Germ cells undergoing meiosis rely on an intricate network of surveillance mechanisms that govern the production of euploid gametes for successful sexual reproduction. These surveillance mechanisms are particularly crucial during meiotic prophase, when cells execute a highly orchestrated program of chromosome morphogenesis and recombination, which must be integrated with the meiotic cell division machinery to ensure the safe execution of meiosis. Dynamic protein phosphorylation, controlled by kinases and phosphatases, has emerged as one of the main signaling routes for providing readout and regulation of chromosomal and cellular behavior throughout meiotic prophase. In this review, we discuss common principles and provide detailed examples of how these phosphorylation events are employed to ensure faithful passage of chromosomes from one generation to the next.
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Affiliation(s)
- Funda M Kar
- Department of Biology, New York University, New York, NY, United States
| | - Andreas Hochwagen
- Department of Biology, New York University, New York, NY, United States
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25
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Tripuraneni V, Memisoglu G, MacAlpine HK, Tran TQ, Zhu W, Hartemink AJ, Haber JE, MacAlpine DM. Local nucleosome dynamics and eviction following a double-strand break are reversible by NHEJ-mediated repair in the absence of DNA replication. Genome Res 2021; 31:775-788. [PMID: 33811083 PMCID: PMC8092003 DOI: 10.1101/gr.271155.120] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 03/26/2021] [Indexed: 12/27/2022]
Abstract
We interrogated at nucleotide resolution the spatiotemporal order of chromatin changes that occur immediately following a site-specific double-strand break (DSB) upstream of the PHO5 locus and its subsequent repair by nonhomologous end joining (NHEJ). We observed the immediate eviction of a nucleosome flanking the break and the repositioning of adjacent nucleosomes away from the break. These early chromatin events were independent of the end-processing Mre11-Rad50-Xrs2 (MRX) complex and preceded the MRX-dependent broad eviction of histones and DNA end-resectioning that extends up to ∼8 kb away from the break. We also examined the temporal dynamics of NHEJ-mediated repair in a G1-arrested population. Concomitant with DSB repair by NHEJ, we observed the redeposition and precise repositioning of nucleosomes at their originally occupied positions. This re-establishment of the prelesion chromatin landscape suggests that a DNA replication-independent mechanism exists to preserve epigenome organization following DSB repair.
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Affiliation(s)
- Vinay Tripuraneni
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Gonen Memisoglu
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637, USA
| | - Heather K MacAlpine
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Trung Q Tran
- Department of Computer Science, Duke University, Durham, North Carolina 27708, USA
| | - Wei Zhu
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | | | - James E Haber
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, USA
| | - David M MacAlpine
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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26
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García Fernández F, Lemos B, Khalil Y, Batrin R, Haber JE, Fabre E. Modified chromosome structure caused by phosphomimetic H2A modulates the DNA damage response by increasing chromatin mobility in yeast. J Cell Sci 2021; 134:jcs.258500. [PMID: 33622771 DOI: 10.1242/jcs.258500] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 02/06/2021] [Indexed: 12/23/2022] Open
Abstract
In budding yeast and mammals, double-strand breaks (DSBs) trigger global chromatin mobility together with rapid phosphorylation of histone H2A over an extensive region of the chromatin. To assess the role of H2A phosphorylation in this response to DNA damage, we have constructed strains where H2A has been mutated to the phosphomimetic H2A-S129E. We show that mimicking H2A phosphorylation leads to an increase in global chromatin mobility in the absence of DNA damage. The intrinsic chromatin mobility of H2A-S129E is not due to downstream checkpoint activation, histone degradation or kinetochore anchoring. Rather, the increased intrachromosomal distances observed in the H2A-S129E mutant are consistent with chromatin structural changes. Strikingly, in this context the Rad9-dependent checkpoint becomes dispensable. Moreover, increased chromatin dynamics in the H2A-S129E mutant correlates with improved DSB repair by non-homologous end joining and a sharp decrease in interchromosomal translocation rate. We propose that changes in chromosomal conformation due to H2A phosphorylation are sufficient to modulate the DNA damage response and maintain genome integrity.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Fabiola García Fernández
- Institut de recherche Saint-Louis (IRSL), Université de Paris, INSERM U944, CNRS UMR7212, Genome and Cell Biology of Diseases Unit, F-75010 Paris, France
| | - Brenda Lemos
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454-9110, USA
| | - Yasmine Khalil
- Institut de recherche Saint-Louis (IRSL), Université de Paris, INSERM U944, CNRS UMR7212, Genome and Cell Biology of Diseases Unit, F-75010 Paris, France
| | - Renaud Batrin
- Institut de recherche Saint-Louis (IRSL), Université de Paris, INSERM U944, CNRS UMR7212, Genome and Cell Biology of Diseases Unit, F-75010 Paris, France
| | - James E Haber
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454-9110, USA
| | - Emmanuelle Fabre
- Institut de recherche Saint-Louis (IRSL), Université de Paris, INSERM U944, CNRS UMR7212, Genome and Cell Biology of Diseases Unit, F-75010 Paris, France
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27
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Usui T, Shinohara A. Rad9, a 53BP1 Ortholog of Budding Yeast, Is Insensitive to Spo11-Induced Double-Strand Breaks During Meiosis. Front Cell Dev Biol 2021; 9:635383. [PMID: 33842461 PMCID: PMC8027355 DOI: 10.3389/fcell.2021.635383] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/25/2021] [Indexed: 12/04/2022] Open
Abstract
Exogenous double-strand breaks (DSBs) induce a DNA damage response during mitosis as well as meiosis. The DNA damage response is mediated by a cascade involving Mec1/Tel1 (ATR/ATM) and Rad53 (Chk2) kinases. Meiotic cells are programmed to form DSBs for the initiation of meiotic recombination. In budding yeast, Spo11-mediated meiotic DSBs activate Mec1/Tel1, but not Rad53; however, the mechanism underlying the insensitivity of Rad53 to meiotic DSBs remains largely unknown. In this study, we found that meiotic cells activate Rad53 in response to exogenous DSBs and that this activation is dependent on an epigenetic marker, Dot1-dependent histone H3K79 methylation, which becomes a scaffold of an Rad53 mediator, Rad9, an ortholog of 53BP1. In contrast, Rad9 is insensitive to meiotic programmed DSBs. This insensitiveness of Rad9 derives from its inability to bind to the DSBs. Indeed, artificial tethering of Rad9 to the meiotic DSBs activated Rad53. The artificial activation of Rad53 kinase in meiosis decreases the repair of meiotic DSBs. These results suggest that the suppression of Rad53 activation is a key event in initiating a meiotic program that repairs programmed DSBs.
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Affiliation(s)
- Takehiko Usui
- Institute for Protein Research, Osaka University, Suita, Japan
| | - Akira Shinohara
- Institute for Protein Research, Osaka University, Suita, Japan
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28
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Peritore M, Reusswig KU, Bantele SCS, Straub T, Pfander B. Strand-specific ChIP-seq at DNA breaks distinguishes ssDNA versus dsDNA binding and refutes single-stranded nucleosomes. Mol Cell 2021; 81:1841-1853.e4. [PMID: 33651987 DOI: 10.1016/j.molcel.2021.02.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 12/30/2020] [Accepted: 01/29/2021] [Indexed: 02/07/2023]
Abstract
In a first step of DNA double-strand break (DSB) repair by homologous recombination, DNA ends are resected such that single-stranded DNA (ssDNA) overhangs are generated. ssDNA is specifically bound by RPA and other factors, which constitutes a ssDNA-domain on damaged chromatin. The molecular organization of this ssDNA and the adjacent dsDNA domain is crucial during DSB signaling and repair. However, data regarding the presence of nucleosomes, the most basic chromatin components, in the ssDNA domain have been contradictory. Here, we use site-specific induction of DSBs and chromatin immunoprecipitation followed by strand-specific sequencing to analyze in vivo binding of key DSB repair and signaling proteins to either the ssDNA or dsDNA domain. In the case of nucleosomes, we show that recently proposed ssDNA nucleosomes are not a major, persistent species, but that nucleosome eviction and DNA end resection are intrinsically coupled. These results support a model of separated dsDNA-nucleosome and ssDNA-RPA domains during DSB repair.
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Affiliation(s)
- Martina Peritore
- Research Group DNA Replication and Genome Integrity, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Karl-Uwe Reusswig
- Research Group DNA Replication and Genome Integrity, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Susanne C S Bantele
- Research Group DNA Replication and Genome Integrity, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Tobias Straub
- Biomedizinisches Centrum, Core Facility Bioinformatics, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany
| | - Boris Pfander
- Research Group DNA Replication and Genome Integrity, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.
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29
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Fedorov DV, Evstyukhina TA, Peshekhonov VT, Korolev VG. Pph3 Phosphatase Participates in the Regulation of the Error-Free Branch of Postreplication DNA Repair in Yeast Saccharomyces cerevisiae. RUSS J GENET+ 2021. [DOI: 10.1134/s1022795421010063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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30
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Forey R, Barthe A, Tittel-Elmer M, Wery M, Barrault MB, Ducrot C, Seeber A, Krietenstein N, Szachnowski U, Skrzypczak M, Ginalski K, Rowicka M, Cobb JA, Rando OJ, Soutourina J, Werner M, Dubrana K, Gasser SM, Morillon A, Pasero P, Lengronne A, Poli J. A Role for the Mre11-Rad50-Xrs2 Complex in Gene Expression and Chromosome Organization. Mol Cell 2020; 81:183-197.e6. [PMID: 33278361 DOI: 10.1016/j.molcel.2020.11.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 11/03/2020] [Accepted: 11/05/2020] [Indexed: 01/09/2023]
Abstract
Mre11-Rad50-Xrs2 (MRX) is a highly conserved complex with key roles in various aspects of DNA repair. Here, we report a new function for MRX in limiting transcription in budding yeast. We show that MRX interacts physically and colocalizes on chromatin with the transcriptional co-regulator Mediator. MRX restricts transcription of coding and noncoding DNA by a mechanism that does not require the nuclease activity of Mre11. MRX is required to tether transcriptionally active loci to the nuclear pore complex (NPC), and it also promotes large-scale gene-NPC interactions. Moreover, MRX-mediated chromatin anchoring to the NPC contributes to chromosome folding and helps to control gene expression. Together, these findings indicate that MRX has a role in transcription and chromosome organization that is distinct from its known function in DNA repair.
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Affiliation(s)
- Romain Forey
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labéllisée Ligue contre le Cancer, 34396 Montpellier, France
| | - Antoine Barthe
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labéllisée Ligue contre le Cancer, 34396 Montpellier, France
| | - Mireille Tittel-Elmer
- Departments of Biochemistry and Molecular Biology and Oncology, Robson DNA Science Centre, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Maxime Wery
- Institut Curie, PSL Research University, CNRS UMR 3244, ncRNA, Epigenetic and Genome Fluidity, Université Pierre et Marie Curie, 26 rue d'Ulm, 75248 Paris, France
| | - Marie-Bénédicte Barrault
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Cécile Ducrot
- Institute of Molecular and Cellular Radiobiology, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA)/Direction de la Recherche Fondamentale (DRF), 92260 Fontenay-aux-Roses Cedex, France
| | - Andrew Seeber
- Center for Advanced Imaging, Harvard University, Cambridge, MA 02138, USA; University of Basel and Friedrich Miescher Institute for Biomedical Research, Faculty of Natural Sciences, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Nils Krietenstein
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ugo Szachnowski
- Institut Curie, PSL Research University, CNRS UMR 3244, ncRNA, Epigenetic and Genome Fluidity, Université Pierre et Marie Curie, 26 rue d'Ulm, 75248 Paris, France
| | - Magdalena Skrzypczak
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Krzysztof Ginalski
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Maga Rowicka
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Jennifer A Cobb
- Departments of Biochemistry and Molecular Biology and Oncology, Robson DNA Science Centre, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Oliver J Rando
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Julie Soutourina
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Michel Werner
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France
| | - Karine Dubrana
- Institute of Molecular and Cellular Radiobiology, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA)/Direction de la Recherche Fondamentale (DRF), 92260 Fontenay-aux-Roses Cedex, France
| | - Susan M Gasser
- University of Basel and Friedrich Miescher Institute for Biomedical Research, Faculty of Natural Sciences, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Antonin Morillon
- Institut Curie, PSL Research University, CNRS UMR 3244, ncRNA, Epigenetic and Genome Fluidity, Université Pierre et Marie Curie, 26 rue d'Ulm, 75248 Paris, France
| | - Philippe Pasero
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labéllisée Ligue contre le Cancer, 34396 Montpellier, France
| | - Armelle Lengronne
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labéllisée Ligue contre le Cancer, 34396 Montpellier, France.
| | - Jérôme Poli
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labéllisée Ligue contre le Cancer, 34396 Montpellier, France; University of Basel and Friedrich Miescher Institute for Biomedical Research, Faculty of Natural Sciences, Klingelbergstrasse 50, 4056 Basel, Switzerland.
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31
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Palmer N, Talib SZA, Singh P, Goh CMF, Liu K, Schimenti JC, Kaldis P. A novel function for CDK2 activity at meiotic crossover sites. PLoS Biol 2020; 18:e3000903. [PMID: 33075054 PMCID: PMC7595640 DOI: 10.1371/journal.pbio.3000903] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 10/29/2020] [Accepted: 09/14/2020] [Indexed: 12/23/2022] Open
Abstract
Genetic diversity in offspring is induced by meiotic recombination, which is initiated between homologs at >200 sites originating from meiotic double-strand breaks (DSBs). Of this initial pool, only 1-2 DSBs per homolog pair will be designated to form meiotic crossovers (COs), where reciprocal genetic exchange occurs between parental chromosomes. Cyclin-dependent kinase 2 (CDK2) is known to localize to so-called "late recombination nodules" (LRNs) marking incipient CO sites. However, the role of CDK2 kinase activity in the process of CO formation remains uncertain. Here, we describe the phenotype of 2 Cdk2 point mutants with elevated or decreased activity, respectively. Elevated CDK2 activity was associated with increased numbers of LRN-associated proteins, including CDK2 itself and the MutL homolog 1 (MLH1) component of the MutLγ complex, but did not lead to increased numbers of COs. In contrast, reduced CDK2 activity leads to the complete absence of CO formation during meiotic prophase I. Our data suggest an important role for CDK2 in regulating MLH1 focus numbers and that the activity of this kinase is a key regulatory factor in the formation of meiotic COs.
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Affiliation(s)
- Nathan Palmer
- Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology, and Research), Singapore, Republic of Singapore
- Department of Biochemistry, National University of Singapore (NUS), Singapore, Republic of Singapore
| | - S. Zakiah A. Talib
- Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology, and Research), Singapore, Republic of Singapore
| | - Priti Singh
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Christine M. F. Goh
- Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology, and Research), Singapore, Republic of Singapore
| | - Kui Liu
- Department of Obstetrics and Gynecology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Shenzhen Key Laboratory of Fertility Regulation, Center of Assisted Reproduction and Embryology, The University of Hong Kong—Shenzhen Hospital, Shenzhen, China
| | - John C. Schimenti
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Philipp Kaldis
- Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology, and Research), Singapore, Republic of Singapore
- Department of Biochemistry, National University of Singapore (NUS), Singapore, Republic of Singapore
- Department of Clinical Sciences, Clinical Research Centre, Lund University, Malmö, Sweden
- * E-mail:
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32
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Gobbini E, Casari E, Colombo CV, Bonetti D, Longhese MP. The 9-1-1 Complex Controls Mre11 Nuclease and Checkpoint Activation during Short-Range Resection of DNA Double-Strand Breaks. Cell Rep 2020; 33:108287. [DOI: 10.1016/j.celrep.2020.108287] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 09/08/2020] [Accepted: 09/28/2020] [Indexed: 12/17/2022] Open
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33
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Memisoglu G, Lanz MC, Eapen VV, Jordan JM, Lee K, Smolka MB, Haber JE. Mec1 ATR Autophosphorylation and Ddc2 ATRIP Phosphorylation Regulates DNA Damage Checkpoint Signaling. Cell Rep 2020; 28:1090-1102.e3. [PMID: 31340146 DOI: 10.1016/j.celrep.2019.06.068] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 02/21/2019] [Accepted: 06/18/2019] [Indexed: 11/26/2022] Open
Abstract
In budding yeast, a single DNA double-strand break (DSB) triggers the activation of Mec1ATR-dependent DNA damage checkpoint. After about 12 h, cells turn off the checkpoint signaling and adapt despite the persistence of the DSB. We report that the adaptation involves the autophosphorylation of Mec1 at site S1964. A non-phosphorylatable mec1-S1964A mutant causes cells to arrest permanently in response to a single DSB without affecting the initial kinase activity of Mec1. Autophosphorylation of S1964 is dependent on Ddc1Rad9 and Dpb11TopBP1, and it correlates with the timing of adaptation. We also report that Mec1's binding partner, Ddc2ATRIP, is an inherently stable protein that is degraded specifically upon DNA damage. Ddc2 is regulated extensively through phosphorylation, which, in turn, regulates the localization of the Mec1-Ddc2 complex to DNA lesions. Taken together, these results suggest that checkpoint response is regulated through the autophosphorylation of Mec1 kinase and through the changes in Ddc2 abundance and phosphorylation.
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Affiliation(s)
- Gonen Memisoglu
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454, USA
| | - Michael C Lanz
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Vinay V Eapen
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Jacqueline M Jordan
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454, USA
| | - Kihoon Lee
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454, USA; Seegene, Inc., Ogeum-ro, Songpa-gu, Seoul 05548, Korea
| | - Marcus B Smolka
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - James E Haber
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454, USA.
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34
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Pecinka A, Chevalier C, Colas I, Kalantidis K, Varotto S, Krugman T, Michailidis C, Vallés MP, Muñoz A, Pradillo M. Chromatin dynamics during interphase and cell division: similarities and differences between model and crop plants. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:5205-5222. [PMID: 31626285 DOI: 10.1093/jxb/erz457] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 09/30/2019] [Indexed: 06/10/2023]
Abstract
Genetic information in the cell nucleus controls organismal development and responses to the environment, and finally ensures its own transmission to the next generations. To achieve so many different tasks, the genetic information is associated with structural and regulatory proteins, which orchestrate nuclear functions in time and space. Furthermore, plant life strategies require chromatin plasticity to allow a rapid adaptation to abiotic and biotic stresses. Here, we summarize current knowledge on the organization of plant chromatin and dynamics of chromosomes during interphase and mitotic and meiotic cell divisions for model and crop plants differing as to genome size, ploidy, and amount of genomic resources available. The existing data indicate that chromatin changes accompany most (if not all) cellular processes and that there are both shared and unique themes in the chromatin structure and global chromosome dynamics among species. Ongoing efforts to understand the molecular mechanisms involved in chromatin organization and remodeling have, together with the latest genome editing tools, potential to unlock crop genomes for innovative breeding strategies and improvements of various traits.
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Affiliation(s)
- Ales Pecinka
- Institute of Experimental Botany, Czech Acad Sci, Centre of the Region Haná for Agricultural and Biotechnological Research, Olomouc, Czech Republic
| | | | - Isabelle Colas
- James Hutton Institute, Cell and Molecular Science, Pr Waugh's Lab, Invergowrie, Dundee, UK
| | - Kriton Kalantidis
- Department of Biology, University of Crete, and Institute of Molecular Biology Biotechnology, FoRTH, Heraklion, Greece
| | - Serena Varotto
- Department of Agronomy Animal Food Natural Resources and Environment (DAFNAE) University of Padova, Agripolis viale dell'Università, Legnaro (PD), Italy
| | - Tamar Krugman
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - Christos Michailidis
- Institute of Experimental Botany, Czech Acad Sci, Praha 6 - Lysolaje, Czech Republic
| | - María-Pilar Vallés
- Department of Genetics and Plant Breeding, Estación Experimental Aula Dei (EEAD), Spanish National Research Council (CSIC), Zaragoza, Spain
| | - Aitor Muñoz
- Department of Plant Molecular Genetics, National Center of Biotechnology/Superior Council of Scientific Research, Autónoma University of Madrid, Madrid, Spain
| | - Mónica Pradillo
- Department of Genetics, Physiology and Microbiology, Faculty of Biology, Complutense University of Madrid, Madrid, Spain
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35
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Yeast ATM and ATR kinases use different mechanisms to spread histone H2A phosphorylation around a DNA double-strand break. Proc Natl Acad Sci U S A 2020; 117:21354-21363. [PMID: 32817543 PMCID: PMC7474660 DOI: 10.1073/pnas.2002126117] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
One of the hallmarks of DNA damage is the rapid spreading of phosphorylated histone H2A (γ-H2AX) around a DNA double-strand break (DSB). In the budding yeast Saccharomyces cerevisiae, nearly all H2A isoforms can be phosphorylated, either by Mec1ATR or Tel1ATM checkpoint kinases. We induced a site-specific DSB with HO endonuclease at the MAT locus on chromosome III and monitored the formation of γ-H2AX by chromatin immunoprecipitation (ChIP)-qPCR in order to uncover the mechanisms by which Mec1ATR and Tel1ATM propagate histone modifications across chromatin. With either kinase, γ-H2AX spreads as far as ∼50 kb on both sides of the lesion within 1 h; but the kinetics and distribution of modification around the DSB are significantly different. The total accumulation of phosphorylation is reduced by about half when either of the two H2A genes is mutated to the nonphosphorylatable S129A allele. Mec1 activity is limited by the abundance of its ATRIP partner, Ddc2. Moreover, Mec1 is more efficient than Tel1 at phosphorylating chromatin in trans-at distant undamaged sites that are brought into physical proximity to the DSB. We compared experimental data to mathematical models of spreading mechanisms to determine whether the kinases search for target nucleosomes by primarily moving in three dimensions through the nucleoplasm or in one dimension along the chromatin. Bayesian model selection indicates that Mec1 primarily uses a three-dimensional diffusive mechanism, whereas Tel1 undergoes directed motion along the chromatin.
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36
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Aleksandrov R, Hristova R, Stoynov S, Gospodinov A. The Chromatin Response to Double-Strand DNA Breaks and Their Repair. Cells 2020; 9:cells9081853. [PMID: 32784607 PMCID: PMC7464352 DOI: 10.3390/cells9081853] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 02/07/2023] Open
Abstract
Cellular DNA is constantly being damaged by numerous internal and external mutagenic factors. Probably the most severe type of insults DNA could suffer are the double-strand DNA breaks (DSBs). They sever both DNA strands and compromise genomic stability, causing deleterious chromosomal aberrations that are implicated in numerous maladies, including cancer. Not surprisingly, cells have evolved several DSB repair pathways encompassing hundreds of different DNA repair proteins to cope with this challenge. In eukaryotic cells, DSB repair is fulfilled in the immensely complex environment of the chromatin. The chromatin is not just a passive background that accommodates the multitude of DNA repair proteins, but it is a highly dynamic and active participant in the repair process. Chromatin alterations, such as changing patterns of histone modifications shaped by numerous histone-modifying enzymes and chromatin remodeling, are pivotal for proficient DSB repair. Dynamic chromatin changes ensure accessibility to the damaged region, recruit DNA repair proteins, and regulate their association and activity, contributing to DSB repair pathway choice and coordination. Given the paramount importance of DSB repair in tumorigenesis and cancer progression, DSB repair has turned into an attractive target for the development of novel anticancer therapies, some of which have already entered the clinic.
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37
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Makarevich O, Sabirzhanov B, Aubrecht TG, Glaser EP, Polster BM, Henry RJ, Faden AI, Stoica BA. Mithramycin selectively attenuates DNA-damage-induced neuronal cell death. Cell Death Dis 2020; 11:587. [PMID: 32719328 PMCID: PMC7385624 DOI: 10.1038/s41419-020-02774-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 07/06/2020] [Accepted: 07/10/2020] [Indexed: 12/15/2022]
Abstract
DNA damage triggers cell death mechanisms contributing to neuronal loss and cognitive decline in neurological disorders, including traumatic brain injury (TBI), and as a side effect of chemotherapy. Mithramycin, which competitively targets chromatin-binding sites of specificity protein 1 (Sp1), was used to examine previously unexplored neuronal cell death regulatory mechanisms via rat primary neurons in vitro and after TBI in mice (males). In primary neurons exposed to DNA-damage-inducing chemotherapy drugs in vitro we showed that DNA breaks sequentially initiate DNA-damage responses, including phosphorylation of ATM, H2AX and tumor protein 53 (p53), transcriptional activation of pro-apoptotic BH3-only proteins, and mitochondrial outer membrane permeabilization (MOMP), activating caspase-dependent and caspase-independent intrinsic apoptosis. Mithramycin was highly neuroprotective in DNA-damage-dependent neuronal cell death, inhibiting chemotherapeutic-induced cell death cascades downstream of ATM and p53 phosphorylation/activation but upstream of p53-induced expression of pro-apoptotic molecules. Mithramycin reduced neuronal upregulation of BH3-only proteins and mitochondrial dysfunction, attenuated caspase-3/7 activation and caspase substrates' cleavage, and limited c-Jun activation. Chromatin immunoprecipitation indicated that mithramycin attenuates Sp1 binding to pro-apoptotic gene promoters without altering p53 binding suggesting it acts by removing cofactors required for p53 transactivation. In contrast, the DNA-damage-independent neuronal death models displayed caspase initiation in the absence of p53/BH3 activation and were not protected even when mithramycin reduced caspase activation. Interestingly, experimental TBI triggers a multiplicity of neuronal death mechanisms. Although markers of DNA-damage/p53-dependent intrinsic apoptosis are detected acutely in the injured cortex and are attenuated by mithramycin, these processes may play a reduced role in early neuronal death after TBI, as caspase-dependent mechanisms are repressed in mature neurons while other, mithramycin-resistant mechanisms are active. Our data suggest that Sp1 is required for p53-mediated transactivation of neuronal pro-apoptotic molecules and that mithramycin may attenuate neuronal cell death in conditions predominantly involving DNA-damage-induced p53-dependent intrinsic apoptosis.
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Affiliation(s)
- Oleg Makarevich
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Boris Sabirzhanov
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Taryn G Aubrecht
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Ethan P Glaser
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Brian M Polster
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Rebecca J Henry
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Alan I Faden
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Bogdan A Stoica
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
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38
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Reginato G, Cejka P. The MRE11 complex: A versatile toolkit for the repair of broken DNA. DNA Repair (Amst) 2020; 91-92:102869. [PMID: 32480356 DOI: 10.1016/j.dnarep.2020.102869] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 12/13/2022]
Abstract
When DNA breaks, the ends need to be stabilized and processed to facilitate subsequent repair, which can occur by either direct but error-prone end-joining with another broken DNA molecule or a more accurate homology-directed repair by the recombination machinery. At the same time, the presence of broken DNA triggers a signaling cascade that regulates the repair events and cellular progression through the cell cycle. The MRE11 nuclease, together with RAD50 and NBS1 forms a complex termed MRN that participates in all these processes. Although MRE11 was first identified more than 20 years ago, deep insights into its mechanism of action and regulation are much more recent. Here we review how MRE11 functions within MRN, and how the complex is further regulated by CtIP and its phosphorylation in a cell cycle dependent manner. We describe how RAD50, NBS1 and CtIP convert MRE11, exhibiting per se a 3'→5' exonuclease activity, into an ensemble that instead degrades primarily the 5'-terminated strand by endonucleolytic cleavage at DNA break sites to generate 3' overhangs, as required for the initiation of homologous recombination. The unique mechanism of DNA end resection by MRN-CtIP makes it a very flexible toolkit to process DNA breaks with a variety of secondary structures and protein blocks. Such a block can also be the Ku heterodimer, and emerging evidence suggests that MRN-CtIP may often need to remove Ku from DNA ends before initiating homologous recombination. Misregulation of DNA break repair results in mutations and chromosome rearrangements that can drive cancer development. Therefore, a detailed understanding of the underlying processes is highly relevant for human health.
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Affiliation(s)
- Giordano Reginato
- Institute for Research in Biomedicine, Università della Svizzera Italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
| | - Petr Cejka
- Institute for Research in Biomedicine, Università della Svizzera Italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland.
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39
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Abstract
Cells confront DNA damage in every cell cycle. Among the most deleterious types of DNA damage are DNA double-strand breaks (DSBs), which can cause cell lethality if unrepaired or cancers if improperly repaired. In response to DNA DSBs, cells activate a complex DNA damage checkpoint (DDC) response that arrests the cell cycle, reprograms gene expression, and mobilizes DNA repair factors to prevent the inheritance of unrepaired and broken chromosomes. Here we examine the DDC, induced by DNA DSBs, in the budding yeast model system and in mammals.
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Affiliation(s)
- David P Waterman
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, USA;
| | - James E Haber
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, USA;
| | - Marcus B Smolka
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853, USA;
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40
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Liu Y, Zou RS, He S, Nihongaki Y, Li X, Razavi S, Wu B, Ha T. Very fast CRISPR on demand. Science 2020; 368:1265-1269. [PMID: 32527834 PMCID: PMC7608738 DOI: 10.1126/science.aay8204] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 12/29/2019] [Accepted: 04/14/2020] [Indexed: 01/01/2023]
Abstract
CRISPR-Cas systems provide versatile tools for programmable genome editing. Here, we developed a caged RNA strategy that allows Cas9 to bind DNA but not cleave until light-induced activation. This approach, referred to as very fast CRISPR (vfCRISPR), creates double-strand breaks (DSBs) at the submicrometer and second scales. Synchronized cleavage improved kinetic analysis of DNA repair, revealing that cells respond to Cas9-induced DSBs within minutes and can retain MRE11 after DNA ligation. Phosphorylation of H2AX after DNA damage propagated more than 100 kilobases per minute, reaching up to 30 megabases. Using single-cell fluorescence imaging, we characterized multiple cycles of 53BP1 repair foci formation and dissolution, with the first cycle taking longer than subsequent cycles and its duration modulated by inhibition of repair. Imaging-guided subcellular Cas9 activation further facilitated genomic manipulation with single-allele resolution. vfCRISPR enables DNA-repair studies at high resolution in space, time, and genomic coordinates.
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Affiliation(s)
- Yang Liu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, USA.
| | - Roger S Zou
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
| | - Shuaixin He
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - Yuta Nihongaki
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Xiaoguang Li
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Shiva Razavi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
| | - Bin Wu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, USA.
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
- The Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, USA.
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA
- Howard Hughes Medical Institute, Baltimore, MD, USA
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The Anticancer Drug 3-Bromopyruvate Induces DNA Damage Potentially Through Reactive Oxygen Species in Yeast and in Human Cancer Cells. Cells 2020; 9:cells9051161. [PMID: 32397119 PMCID: PMC7290944 DOI: 10.3390/cells9051161] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 05/05/2020] [Accepted: 05/06/2020] [Indexed: 12/13/2022] Open
Abstract
3-bromopyruvate (3-BP) is a small molecule with anticancer and antimicrobial activities. 3-BP is taken up selectively by cancer cells’ mono-carboxylate transporters (MCTs), which are highly overexpressed by many cancers. When 3-BP enters cancer cells it inactivates several glycolytic and mitochondrial enzymes, leading to ATP depletion and the generation of reactive oxygen species. While mechanisms of 3-BP uptake and its influence on cell metabolism are well understood, the impact of 3-BP at certain concentrations on DNA integrity has never been investigated in detail. Here we have collected several lines of evidence suggesting that 3-BP induces DNA damage probably as a result of ROS generation, in both yeast and human cancer cells, when its concentration is sufficiently low and most cells are still viable. We also demonstrate that in yeast 3-BP treatment leads to generation of DNA double-strand breaks only in S-phase of the cell cycle, possibly as a result of oxidative DNA damage. This leads to DNA damage, checkpoint activation and focal accumulation of the DNA response proteins. Interestingly, in human cancer cells exposure to 3-BP also induces DNA breaks that trigger H2A.X phosphorylation. Our current data shed new light on the mechanisms by which a sufficiently low concentration of 3-BP can induce cytotoxicity at the DNA level, a finding that might be important for the future design of anticancer therapies.
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Colombo CV, Gnugnoli M, Gobbini E, Longhese MP. How do cells sense DNA lesions? Biochem Soc Trans 2020; 48:677-691. [PMID: 32219379 DOI: 10.1042/bst20191118] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/06/2020] [Accepted: 03/12/2020] [Indexed: 12/17/2023]
Abstract
DNA is exposed to both endogenous and exogenous DNA damaging agents that chemically modify it. To counteract the deleterious effects exerted by DNA lesions, eukaryotic cells have evolved a network of cellular pathways, termed DNA damage response (DDR). The DDR comprises both mechanisms devoted to repair DNA lesions and signal transduction pathways that sense DNA damage and transduce this information to specific cellular targets. These targets, in turn, impact a wide range of cellular processes including DNA replication, DNA repair and cell cycle transitions. The importance of the DDR is highlighted by the fact that DDR inactivation is commonly found in cancer and causes many different human diseases. The protein kinases ATM and ATR, as well as their budding yeast orthologs Tel1 and Mec1, act as master regulators of the DDR. The initiating events in the DDR entail both DNA lesion recognition and assembly of protein complexes at the damaged DNA sites. Here, we review what is known about the early steps of the DDR.
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Affiliation(s)
- Chiara Vittoria Colombo
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy
| | - Marco Gnugnoli
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy
| | - Elisa Gobbini
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy
| | - Maria Pia Longhese
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy
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43
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Harpprecht L, Baldi S, Schauer T, Schmidt A, Bange T, Robles MS, Kremmer E, Imhof A, Becker PB. A Drosophila cell-free system that senses DNA breaks and triggers phosphorylation signalling. Nucleic Acids Res 2019; 47:7444-7459. [PMID: 31147711 PMCID: PMC6698661 DOI: 10.1093/nar/gkz473] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/13/2019] [Accepted: 05/16/2019] [Indexed: 11/23/2022] Open
Abstract
Preblastoderm Drosophila embryo development is characterized by fast cycles of nuclear divisions. Extracts from these embryos can be used to reconstitute complex chromatin with high efficiency. We now discovered that this chromatin assembly system contains activities that recognize unprotected DNA ends and signal DNA damage through phosphorylation. DNA ends are initially bound by Ku and MRN complexes. Within minutes, the phosphorylation of H2A.V (homologous to γH2A.X) initiates from DNA breaks and spreads over tens of thousands DNA base pairs. The γH2A.V phosphorylation remains tightly associated with the damaged DNA and does not spread to undamaged DNA in the same reaction. This first observation of long-range γH2A.X spreading along damaged chromatin in an in vitro system provides a unique opportunity for mechanistic dissection. Upon further incubation, DNA ends are rendered single-stranded and bound by the RPA complex. Phosphoproteome analyses reveal damage-dependent phosphorylation of numerous DNA-end-associated proteins including Ku70, RPA2, CHRAC16, the exonuclease Rrp1 and the telomer capping complex. Phosphorylation of spindle assembly checkpoint components and of microtubule-associated proteins required for centrosome integrity suggests this cell-free system recapitulates processes involved in the regulated elimination of fatally damaged syncytial nuclei.
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Affiliation(s)
- Lisa Harpprecht
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Sandro Baldi
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
- Center for Integrated Protein Science Munich, LMU Munich, 81377 Munich, Germany
| | - Tamas Schauer
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
- Bioinformatics Unit, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Andreas Schmidt
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
- Protein Analysis Unit, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Tanja Bange
- Institute of Medical Psychology, LMU Munich, 80336 Munich, Germany
| | - Maria S Robles
- Institute of Medical Psychology, LMU Munich, 80336 Munich, Germany
| | - Elisabeth Kremmer
- Institute of Molecular Immunology, German Research Center for Environmental Health, 81377 Munich, Germany
| | - Axel Imhof
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
- Center for Integrated Protein Science Munich, LMU Munich, 81377 Munich, Germany
- Protein Analysis Unit, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Peter B Becker
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
- Center for Integrated Protein Science Munich, LMU Munich, 81377 Munich, Germany
- To whom correspondence should be addressed. Tel: +49 89 2180 75427; Fax: +49 89 2180 75425;
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House NC, Polleys EJ, Quasem I, De la Rosa Mejia M, Joyce CE, Takacsi-Nagy O, Krebs JE, Fuchs SM, Freudenreich CH. Distinct roles for S. cerevisiae H2A copies in recombination and repeat stability, with a role for H2A.1 threonine 126. eLife 2019; 8:53362. [PMID: 31804179 PMCID: PMC6927750 DOI: 10.7554/elife.53362] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 11/26/2019] [Indexed: 01/14/2023] Open
Abstract
CAG/CTG trinuncleotide repeats are fragile sequences that when expanded form DNA secondary structures and cause human disease. We evaluated CAG/CTG repeat stability and repair outcomes in histone H2 mutants in S. cerevisiae. Although the two copies of H2A are nearly identical in amino acid sequence, CAG repeat stability depends on H2A copy 1 (H2A.1) but not copy 2 (H2A.2). H2A.1 promotes high-fidelity homologous recombination, sister chromatid recombination (SCR), and break-induced replication whereas H2A.2 does not share these functions. Both decreased SCR and the increase in CAG expansions were due to the unique Thr126 residue in H2A.1 and hta1Δ or hta1-T126A mutants were epistatic to deletion of the Polδ subunit Pol32, suggesting a role for H2A.1 in D-loop extension. We conclude that H2A.1 plays a greater repair-specific role compared to H2A.2 and may be a first step towards evolution of a repair-specific function for H2AX compared to H2A in mammalian cells.
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Affiliation(s)
- Nealia Cm House
- Department of Biology, Tufts University, Medford, United States
| | - Erica J Polleys
- Department of Biology, Tufts University, Medford, United States
| | | | | | - Cailin E Joyce
- Department of Biology, Tufts University, Medford, United States
| | | | - Jocelyn E Krebs
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, United States
| | - Stephen M Fuchs
- Department of Biology, Tufts University, Medford, United States
| | - Catherine H Freudenreich
- Department of Biology, Tufts University, Medford, United States.,Program in Genetics, Graduate School of Biomedical Sciences, Tufts University, Boston, United States
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45
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Hu Q, Lu H, Wang H, Li S, Truong L, Li J, Liu S, Xiang R, Wu X. Break-induced replication plays a prominent role in long-range repeat-mediated deletion. EMBO J 2019; 38:e101751. [PMID: 31571254 DOI: 10.15252/embj.2019101751] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 09/07/2019] [Accepted: 09/11/2019] [Indexed: 12/17/2022] Open
Abstract
Repetitive DNA sequences are often associated with chromosomal rearrangements in cancers. Conventionally, single-strand annealing (SSA) is thought to mediate homology-directed repair of double-strand breaks (DSBs) between two repeats, causing repeat-mediated deletion (RMD). In this report, we demonstrate that break-induced replication (BIR) is used predominantly over SSA in mammalian cells for mediating RMD, especially when repeats are far apart. We show that SSA becomes inefficient in mammalian cells when the distance between the DSBs and the repeats is increased to the 1-2 kb range, while BIR-mediated RMD (BIR/RMD) can act over a long distance (e.g., ~ 100-200 kb) when the DSB is close to one repeat. Importantly, oncogene expression potentiates BIR/RMD but not SSA, and BIR/RMD is used more frequently at single-ended DSBs formed at collapsed replication forks than at double-ended DSBs. In contrast to short-range SSA, H2AX is required for long-range BIR/RMD, and sequence divergence strongly suppresses BIR/RMD in a manner partially dependent on MSH2. Our finding that BIR/RMD has a more important role than SSA in mammalian cells has a significant impact on the understanding of repeat-mediated rearrangements associated with oncogenesis.
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Affiliation(s)
- Qing Hu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Hongyan Lu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.,School of Medicine, Nankai University, Tianjin, China
| | - Hongjun Wang
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Shibo Li
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Lan Truong
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Jun Li
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.,School of Medicine, Nankai University, Tianjin, China
| | - Shuo Liu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.,School of Medicine, Nankai University, Tianjin, China
| | - Rong Xiang
- School of Medicine, Nankai University, Tianjin, China
| | - Xiaohua Wu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
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46
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Abstract
Maintaining the integrity of the genome in the face of DNA damage is crucial to ensure the survival of the cell and normal development. DNA lesions and repair occur in the context of the chromatin fiber, whose 3D organization and movements in the restricted volume of the nucleus are under intense scrutiny. Here, we highlight work from our and other labs that addresses how the dynamic organization of the chromatin fiber affects the repair of damaged DNA and how, conversely, DNA damage and repair affect the structure and dynamics of chromatin in the budding yeast nucleus.
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Affiliation(s)
- Emmanuelle Fabre
- a Equipe Biologie et Dynamique des Chromosomes , Institut Universitaire d'Hématologie, Hôpital St. Louis , Paris , France.,b CNRS, UMR 7212 INSERM U944, IUH, Université Paris Diderot Sorbonne Paris Cité , Paris , France
| | - Christophe Zimmer
- c Institut Pasteur, Unité Imagerie et Modélisation , 25 rue du Docteur Roux, 75015 , Paris , France.,d UMR 3691, CNRS; C3BI, USR 3756, IP CNRS , Paris , France
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47
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Pich D, Mrozek-Gorska P, Bouvet M, Sugimoto A, Akidil E, Grundhoff A, Hamperl S, Ling PD, Hammerschmidt W. First Days in the Life of Naive Human B Lymphocytes Infected with Epstein-Barr Virus. mBio 2019; 10:e01723-19. [PMID: 31530670 PMCID: PMC6751056 DOI: 10.1128/mbio.01723-19] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 08/16/2019] [Indexed: 12/14/2022] Open
Abstract
Epstein-Barr virus (EBV) infects and activates resting human B lymphocytes, reprograms them, induces their proliferation, and establishes a latent infection in them. In established EBV-infected cell lines, many viral latent genes are expressed. Their roles in supporting the continuous proliferation of EBV-infected B cells in vitro are known, but their functions in the early, prelatent phase of infection have not been investigated systematically. In studies during the first 8 days of infection using derivatives of EBV with mutations in single genes of EBVs, we found only Epstein-Barr nuclear antigen 2 (EBNA2) to be essential for activating naive human B lymphocytes, inducing their growth in cell volume, driving them into rapid cell divisions, and preventing cell death in a subset of infected cells. EBNA-LP, latent membrane protein 2A (LMP2A), and the viral microRNAs have supportive, auxiliary functions, but mutants of LMP1, EBNA3A, EBNA3C, and the noncoding Epstein-Barr virus with small RNA (EBERs) had no discernible phenotype compared with wild-type EBV. B cells infected with a double mutant of EBNA3A and 3C had an unexpected proliferative advantage and did not regulate the DNA damage response (DDR) of the infected host cell in the prelatent phase. Even EBNA1, which has very critical long-term functions in maintaining and replicating the viral genomic DNA in established cell lines, was dispensable for the early activation of infected cells. Our findings document that the virus dose is a decisive parameter and indicate that EBNA2 governs the infected cells initially and implements a strictly controlled temporal program independent of other viral latent genes. It thus appears that EBNA2 is sufficient to control all requirements for clonal cellular expansion and to reprogram human B lymphocytes from energetically quiescent to activated cells.IMPORTANCE The preferred target of Epstein-Barr virus (EBV) is human resting B lymphocytes. We found that their infection induces a well-coordinated, time-driven program that starts with a substantial increase in cell volume, followed by cellular DNA synthesis after 3 days and subsequent rapid rounds of cell divisions on the next day accompanied by some DNA replication stress (DRS). Two to 3 days later, the cells decelerate and turn into stably proliferating lymphoblast cell lines. With the aid of 16 different recombinant EBV strains, we investigated the individual contributions of EBV's multiple latent genes during early B-cell infection and found that many do not exert a detectable phenotype or contribute little to EBV's prelatent phase. The exception is EBNA2 that is essential in governing all aspects of B-cell reprogramming. EBV relies on EBNA2 to turn the infected B lymphocytes into proliferating lymphoblasts preparing the infected host cell for the ensuing stable, latent phase of viral infection. In the early steps of B-cell reprogramming, viral latent genes other than EBNA2 are dispensable, but some, EBNA-LP, for example, support the viral program and presumably stabilize the infected cells once viral latency is established.
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Affiliation(s)
- Dagmar Pich
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health and German Center for Infection Research (DZIF), Munich, Germany
| | - Paulina Mrozek-Gorska
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health and German Center for Infection Research (DZIF), Munich, Germany
| | - Mickaël Bouvet
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health and German Center for Infection Research (DZIF), Munich, Germany
| | - Atsuko Sugimoto
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health and German Center for Infection Research (DZIF), Munich, Germany
| | - Ezgi Akidil
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health and German Center for Infection Research (DZIF), Munich, Germany
| | - Adam Grundhoff
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Stephan Hamperl
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
| | - Paul D Ling
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Wolfgang Hammerschmidt
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health and German Center for Infection Research (DZIF), Munich, Germany
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48
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Biswas H, Goto G, Wang W, Sung P, Sugimoto K. Ddc2ATRIP promotes Mec1ATR activation at RPA-ssDNA tracts. PLoS Genet 2019; 15:e1008294. [PMID: 31369547 PMCID: PMC6692047 DOI: 10.1371/journal.pgen.1008294] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 08/13/2019] [Accepted: 07/07/2019] [Indexed: 11/19/2022] Open
Abstract
The DNA damage checkpoint response is controlled by the phosphatidylinositol 3-kinase-related kinases (PIKK), including ataxia telangiectasia-mutated (ATM) and ATM and Rad3-related (ATR). ATR forms a complex with its partner ATRIP. In budding yeast, ATR and ATRIP correspond to Mec1 and Ddc2, respectively. ATRIP/Ddc2 interacts with replication protein A-bound single-stranded DNA (RPA-ssDNA) and recruits ATR/Mec1 to sites of DNA damage. Mec1 is stimulated by the canonical activators including Ddc1, Dpb11 and Dna2. We have characterized the ddc2-S4 mutation and shown that Ddc2 not only recruits Mec1 to sites of DNA damage but also stimulates Mec1 kinase activity. However, the underlying mechanism of Ddc2-dependent Mec1 activation remains to be elucidated. Here we show that Ddc2 promotes Mec1 activation independently of Ddc1/Dpb11/Dna2 function in vivo and through ssDNA recognition in vitro. The ddc2-S4 mutation diminishes damage-induced phosphorylation of the checkpoint mediators, Rad9 and Mrc1. Rad9 controls checkpoint throughout the cell-cycle whereas Mrc1 is specifically required for the S-phase checkpoint. Notably, S-phase checkpoint signaling is more defective in ddc2-S4 mutants than in cells where the Mec1 activators (Ddc1/Dpb11 and Dna2) are dysfunctional. To understand a role of Ddc2 in Mec1 activation, we reconstituted an in vitro assay using purified Mec1-Ddc2 complex, RPA and ssDNA. Whereas ssDNA stimulates kinase activity of the Mec1-Ddc2 complex, RPA does not. However, RPA can promote ssDNA-dependent Mec1 activation. Neither ssDNA nor RPA-ssDNA efficiently stimulates the Mec1-Ddc2 complex containing Ddc2-S4 mutant. Together, our data support a model in which Ddc2 promotes Mec1 activation at RPA-ssDNA tracts.
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Affiliation(s)
- Himadri Biswas
- Department of Microbiology, Biochemistry and Molecular Genetics, International Center for Public Health, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
| | - Greicy Goto
- Department of Microbiology, Biochemistry and Molecular Genetics, International Center for Public Health, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
| | - Weibin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Patrick Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Katsunori Sugimoto
- Department of Microbiology, Biochemistry and Molecular Genetics, International Center for Public Health, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
- * E-mail:
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49
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Varga D, Majoros H, Ujfaludi Z, Erdélyi M, Pankotai T. Quantification of DNA damage induced repair focus formation via super-resolution dSTORM localization microscopy. NANOSCALE 2019; 11:14226-14236. [PMID: 31317161 DOI: 10.1039/c9nr03696b] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In eukaryotic cells, each process, in which DNA is involved, should take place in the context of a chromatin structure. DNA double-strand breaks (DSBs) are one of the most deleterious lesions often leading to chromosomal rearrangement. In response to environmental stresses, cells have developed repair mechanisms to eliminate the DSBs. Upon DSB induction, several factors play roles in chromatin relaxation by catalysing the appropriate histone posttranslational modification (PTM) steps, therefore promoting the access of the repair factors to the DSBs. Among these PTMs, the phosphorylation of the histone variant H2AX at its Ser139 residue (also known as γH2AX) could be observed at the break sites. The structure of a DNA double-strand break induced repair focus has to be organized during the repair as it contributes to the accessibility of specific repair proteins to the damaged site. Our aim was to develop a quantitative approach to analyse the morphology of single repair foci by super-resolution dSTORM microscopy to gain insight into chromatin organization in DNA repair. We have established a specific dSTORM measurement process by developing a new analytical algorithm for gaining quantitative information about chromatin morphology and repair foci topology at an individual γH2AX enriched repair focus. Using this method we quantified single repair foci to show the distribution of γH2AX. The image of individual γH2AX referred to as the Single target Molecule response scatter Plot (SMPlot) was obtained by using high lateral resolution dSTORM images. Determination of the average localization numbers in an SMPlot was one of the key steps of quantitative dSTORM. A repair focus is made up of nanofoci. Such a substructure of repair foci can only be resolved and detected with super-resolution microscopy. Determination of the number of γH2AXs in the nanofoci was another key step of quantitative dSTORM. Additionally, based on our new analysis method, we were able to show the number of nucleosomes in each nanofocus that could allow us to define the possible chromatin structure and the nucleosome density around the break sites. This method is one of the first demonstrations of a single-cell based quantitative measurement of a discrete repair focus, which could provide new opportunities to categorize the spatial organization of nanofoci by parametric determination of topological similarity.
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Affiliation(s)
- Dániel Varga
- University of Szeged, Department of Optics and Quantum Electronics, Hungary.
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50
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Chromatin Profiling of the Repetitive and Nonrepetitive Genomes of the Human Fungal Pathogen Candida albicans. mBio 2019; 10:mBio.01376-19. [PMID: 31337722 PMCID: PMC6650553 DOI: 10.1128/mbio.01376-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The fungus Candida albicans is an opportunistic pathogen that normally lives on the human body without causing any harm. However, C. albicans is also a dangerous pathogen responsible for millions of infections annually. C. albicans is such a successful pathogen because it can adapt to and thrive in different environments. Chemical modifications of chromatin, the structure that packages DNA into cells, can allow environmental adaptation by regulating gene expression and genome organization. Surprisingly, the contribution of chromatin modification to C. albicans biology is still largely unknown. For the first time, we analyzed C. albicans chromatin modifications on a genome-wide basis. We demonstrate that specific chromatin states are associated with distinct regions of the C. albicans genome and identify the roles of the chromatin modifiers Sir2 and Set1 in shaping C. albicans chromatin and gene expression. Eukaryotic genomes are packaged into chromatin structures that play pivotal roles in regulating all DNA-associated processes. Histone posttranslational modifications modulate chromatin structure and function, leading to rapid regulation of gene expression and genome stability, key steps in environmental adaptation. Candida albicans, a prevalent fungal pathogen in humans, can rapidly adapt and thrive in diverse host niches. The contribution of chromatin to C. albicans biology is largely unexplored. Here, we generated the first comprehensive chromatin profile of histone modifications (histone H3 trimethylated on lysine 4 [H3K4me3], histone H3 acetylated on lysine 9 [H3K9Ac], acetylated lysine 16 on histone H4 [H4K16Ac], and γH2A) across the C. albicans genome and investigated its relationship to gene expression by harnessing genome-wide sequencing approaches. We demonstrated that gene-rich nonrepetitive regions are packaged into canonical euchromatin in association with histone modifications that mirror their transcriptional activity. In contrast, repetitive regions are assembled into distinct chromatin states; subtelomeric regions and the ribosomal DNA (rDNA) locus are assembled into heterochromatin, while major repeat sequences and transposons are packaged in chromatin that bears features of euchromatin and heterochromatin. Genome-wide mapping of γH2A, a marker of genome instability, identified potential recombination-prone genomic loci. Finally, we present the first quantitative chromatin profiling in C. albicans to delineate the role of the chromatin modifiers Sir2 and Set1 in controlling chromatin structure and gene expression. This report presents the first genome-wide chromatin profiling of histone modifications associated with the C. albicans genome. These epigenomic maps provide an invaluable resource to understand the contribution of chromatin to C. albicans biology and identify aspects of C. albicans chromatin organization that differ from that of other yeasts.
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