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Spegg V, Altmeyer M. Genome maintenance meets mechanobiology. Chromosoma 2024; 133:15-36. [PMID: 37581649 PMCID: PMC10904543 DOI: 10.1007/s00412-023-00807-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 06/20/2023] [Accepted: 07/26/2023] [Indexed: 08/16/2023]
Abstract
Genome stability is key for healthy cells in healthy organisms, and deregulated maintenance of genome integrity is a hallmark of aging and of age-associated diseases including cancer and neurodegeneration. To maintain a stable genome, genome surveillance and repair pathways are closely intertwined with cell cycle regulation and with DNA transactions that occur during transcription and DNA replication. Coordination of these processes across different time and length scales involves dynamic changes of chromatin topology, clustering of fragile genomic regions and repair factors into nuclear repair centers, mobilization of the nuclear cytoskeleton, and activation of cell cycle checkpoints. Here, we provide a general overview of cell cycle regulation and of the processes involved in genome duplication in human cells, followed by an introduction to replication stress and to the cellular responses elicited by perturbed DNA synthesis. We discuss fragile genomic regions that experience high levels of replication stress, with a particular focus on telomere fragility caused by replication stress at the ends of linear chromosomes. Using alternative lengthening of telomeres (ALT) in cancer cells and ALT-associated PML bodies (APBs) as examples of replication stress-associated clustered DNA damage, we discuss compartmentalization of DNA repair reactions and the role of protein properties implicated in phase separation. Finally, we highlight emerging connections between DNA repair and mechanobiology and discuss how biomolecular condensates, components of the nuclear cytoskeleton, and interfaces between membrane-bound organelles and membraneless macromolecular condensates may cooperate to coordinate genome maintenance in space and time.
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Affiliation(s)
- Vincent Spegg
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland
| | - Matthias Altmeyer
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland.
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2
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Ngai TW, Elfar GA, Yeo P, Phua N, Hor JH, Chen S, Ho YS, Cheok CF. Nitro-Deficient Niclosamide Confers Reduced Genotoxicity and Retains Mitochondrial Uncoupling Activity for Cancer Therapy. Int J Mol Sci 2021; 22:10420. [PMID: 34638761 PMCID: PMC8508655 DOI: 10.3390/ijms221910420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/16/2021] [Accepted: 09/18/2021] [Indexed: 11/16/2022] Open
Abstract
Niclosamide is an oral anthelmintic drug, approved for use against tapeworm infections. Recent studies suggest however that niclosamide may have broader clinical applications in cancers, spurring increased interest in the functions and mechanisms of niclosamide. Previously, we reported that niclosamide targets a metabolic vulnerability in p53-deficient tumours, providing a basis for patient stratification and personalised treatment strategies. In the present study, we functionally characterised the contribution of the aniline 4'-NO2 group on niclosamide to its cellular activities. We demonstrated that niclosamide induces genome-wide DNA damage that is mechanistically uncoupled from its antitumour effects mediated through mitochondrial uncoupling. Elimination of the nitro group in ND-Nic analogue significantly reduced γH2AX signals and DNA breaks while preserving its antitumour mechanism mediated through a calcium signalling pathway and arachidonic acid metabolism. Lipidomics profiling further revealed that ND-Nic-treated cells retained a metabolite profile characteristic of niclosamide-treated cells. Notably, quantitative scoring of drug sensitivity suggests that elimination of its nitro group enhanced the target selectivity of niclosamide against p53 deficiency. Importantly, the results also raise concern that niclosamide may impose a pleiotropic genotoxic effect, which limits its clinical efficacy and warrants further investigation into alternative drug analogues that may ameliorate any potential unwanted side effects.
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Affiliation(s)
- Tsz Wai Ngai
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Singapore; (T.W.N.); (G.A.E.); (P.Y.); (N.P.); (J.H.H.)
| | - Gamal Ahmed Elfar
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Singapore; (T.W.N.); (G.A.E.); (P.Y.); (N.P.); (J.H.H.)
- Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119074, Singapore
| | - Pearlyn Yeo
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Singapore; (T.W.N.); (G.A.E.); (P.Y.); (N.P.); (J.H.H.)
- Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119074, Singapore
| | - Nicholas Phua
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Singapore; (T.W.N.); (G.A.E.); (P.Y.); (N.P.); (J.H.H.)
| | - Jin Hui Hor
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Singapore; (T.W.N.); (G.A.E.); (P.Y.); (N.P.); (J.H.H.)
| | - Shuwen Chen
- Analytical Science and Technology (Metabolomics), Bioprocessing Technology Institute, 20 Biopolis Way, Centros #06-01, Singapore 138668, Singapore; (S.C.); (Y.S.H.)
| | - Ying Swan Ho
- Analytical Science and Technology (Metabolomics), Bioprocessing Technology Institute, 20 Biopolis Way, Centros #06-01, Singapore 138668, Singapore; (S.C.); (Y.S.H.)
| | - Chit Fang Cheok
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Singapore; (T.W.N.); (G.A.E.); (P.Y.); (N.P.); (J.H.H.)
- Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119074, Singapore
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3
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ATR Signaling Uncouples the Role of RAD51 Paralogs in Homologous Recombination and Replication Stress Response. Cell Rep 2019; 29:551-559.e4. [DOI: 10.1016/j.celrep.2019.09.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 07/31/2019] [Accepted: 09/04/2019] [Indexed: 01/09/2023] Open
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4
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Kilic S, Lezaja A, Gatti M, Bianco E, Michelena J, Imhof R, Altmeyer M. Phase separation of 53BP1 determines liquid-like behavior of DNA repair compartments. EMBO J 2019; 38:e101379. [PMID: 31267591 PMCID: PMC6694294 DOI: 10.15252/embj.2018101379] [Citation(s) in RCA: 253] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 05/08/2019] [Accepted: 05/28/2019] [Indexed: 12/13/2022] Open
Abstract
The DNA damage response (DDR) generates transient repair compartments to concentrate repair proteins and activate signaling factors. The physicochemical properties of these spatially confined compartments and their function remain poorly understood. Here, we establish, based on live cell microscopy and CRISPR/Cas9‐mediated endogenous protein tagging, that 53BP1‐marked repair compartments are dynamic, show droplet‐like behavior, and undergo frequent fusion and fission events. 53BP1 assembly, but not the upstream accumulation of γH2AX and MDC1, is highly sensitive to changes in osmotic pressure, temperature, salt concentration and to disruption of hydrophobic interactions. Phase separation of 53BP1 is substantiated by optoDroplet experiments, which further allowed dissection of the 53BP1 sequence elements that cooperate for light‐induced clustering. Moreover, we found the tumor suppressor protein p53 to be enriched within 53BP1 optoDroplets, and conditions that disrupt 53BP1 phase separation impair 53BP1‐dependent induction of p53 and diminish p53 target gene expression. We thus suggest that 53BP1 phase separation integrates localized DNA damage recognition and repair factor assembly with global p53‐dependent gene activation and cell fate decisions.
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Affiliation(s)
- Sinan Kilic
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland
| | - Aleksandra Lezaja
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland.,Cancer Biology PhD Program, Life Science Zurich Graduate School, Zurich, Switzerland
| | - Marco Gatti
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland
| | - Eliana Bianco
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland.,Cancer Biology PhD Program, Life Science Zurich Graduate School, Zurich, Switzerland
| | - Jone Michelena
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland
| | - Ralph Imhof
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland
| | - Matthias Altmeyer
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland
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5
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Kilic S, Boichenko I, Lechner CC, Fierz B. A bi-terminal protein ligation strategy to probe chromatin structure during DNA damage. Chem Sci 2018; 9:3704-3709. [PMID: 29780501 PMCID: PMC5935033 DOI: 10.1039/c8sc00681d] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 03/15/2018] [Indexed: 12/18/2022] Open
Abstract
The cellular response to DNA damage results in a signaling cascade that primes chromatin for repair. Combinatorial post-translational modifications (PTMs) play an important role in this process by altering the physical properties of chromatin and recruiting downstream factors. One key signal integrator is the histone variant H2A.X, which is phosphorylated at a C-terminal serine (S139ph), and ubiquitylated within its N-terminal tail at lysines 13 and 15 (K13/15ub). How these PTMs directly impact chromatin structure and thereby facilitate DNA repair is not well understood. Detailed studies require synthetic access to such N- and C-terminally modified proteins. This is complicated by the requirement for protecting groups allowing multi-fragment assembly. Here, we report a semi-synthetic route to generate simultaneously N- and C-terminally modified proteins using genetically encoded orthogonal masking groups. Applied to H2A.X, expression of a central protein fragment, containing a protected N-terminal cysteine and a C-terminal thioester masked as a split intein, enables sequential C- and N-terminal protein modification and results in the convergent production of H2A.X carrying K15ub and S139ph. Using single-molecule FRET between defined nucleosomes in synthetic chromatin fibers, we then show that K15 ubiquitylation (but not S139ph) impairs nucleosome stacking in tetranucleosome units, opening chromatin during DNA repair.
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Affiliation(s)
- Sinan Kilic
- Laboratory of Biophysical Chemistry of Macromolecules , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne (EPFL) , 1015 Lausanne , Switzerland .
| | - Iuliia Boichenko
- Laboratory of Biophysical Chemistry of Macromolecules , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne (EPFL) , 1015 Lausanne , Switzerland .
| | - Carolin C Lechner
- Laboratory of Biophysical Chemistry of Macromolecules , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne (EPFL) , 1015 Lausanne , Switzerland .
| | - Beat Fierz
- Laboratory of Biophysical Chemistry of Macromolecules , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne (EPFL) , 1015 Lausanne , Switzerland .
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6
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Replication-Coupled Dilution of H4K20me2 Guides 53BP1 to Pre-replicative Chromatin. Cell Rep 2018; 19:1819-1831. [PMID: 28564601 PMCID: PMC5857200 DOI: 10.1016/j.celrep.2017.05.016] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 04/06/2017] [Accepted: 05/03/2017] [Indexed: 12/21/2022] Open
Abstract
The bivalent histone modification reader 53BP1 accumulates around DNA double-strand breaks (DSBs), where it dictates repair pathway choice decisions by limiting DNA end resection. How this function is regulated locally and across the cell cycle to channel repair reactions toward non-homologous end joining (NHEJ) in G1 and promote homology-directed repair (HDR) in S/G2 is insufficiently understood. Here, we show that the ability of 53BP1 to accumulate around DSBs declines as cells progress through S phase and reveal that the inverse relationship between 53BP1 recruitment and replicated chromatin is linked to the replication-coupled dilution of 53BP1’s target mark H4K20me2. Consistently, premature maturation of post-replicative chromatin restores H4K20me2 and rescues 53BP1 accumulation on replicated chromatin. The H4K20me2-mediated chromatin association of 53BP1 thus represents an inbuilt mechanism to distinguish DSBs in pre- versus post-replicative chromatin, allowing for localized repair pathway choice decisions based on the availability of replication-generated template strands for HDR.
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7
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Abstract
Replication stress is a major source of DNA damage and an important driver of cancer development. Replication intermediates that occur upon mild forms of replication stress frequently escape cell cycle checkpoints and can be transmitted through mitosis into the next cell cycle. The consequences of such inherited DNA lesions for cell fate and survival are poorly understood. By using time-lapse microscopy and quantitative image-based cytometry to simultaneously monitor inherited DNA lesions marked by the genome caretaker protein 53BP1 and cell cycle progression, we show that inheritance of 53BP1-marked lesions from the previous S-phase is associated with a prolonged G1 duration in the next cell cycle. These results suggest that cell-to-cell variation in S-phase commitment is determined, at least partially, by the amount of replication-born inherited DNA damage in individual cells. We further show that loss of the tumor suppressor protein p53 overrides replication stress-induced G1 prolongation and allows S-phase entry with excessive amounts of inherited DNA lesions. Thus, replication stress and p53 loss may synergize during cancer development by promoting cell cycle re-entry with unrepaired mutagenic DNA lesions originating from the previous cell cycle.
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Affiliation(s)
- Aleksandra Lezaja
- a Department of Molecular Mechanisms of Disease , University of Zurich , Zurich , CH , Switzerland
| | - Matthias Altmeyer
- a Department of Molecular Mechanisms of Disease , University of Zurich , Zurich , CH , Switzerland
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8
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Chatterjee N, Walker GC. Mechanisms of DNA damage, repair, and mutagenesis. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:235-263. [PMID: 28485537 PMCID: PMC5474181 DOI: 10.1002/em.22087] [Citation(s) in RCA: 959] [Impact Index Per Article: 137.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 03/16/2017] [Indexed: 05/08/2023]
Abstract
Living organisms are continuously exposed to a myriad of DNA damaging agents that can impact health and modulate disease-states. However, robust DNA repair and damage-bypass mechanisms faithfully protect the DNA by either removing or tolerating the damage to ensure an overall survival. Deviations in this fine-tuning are known to destabilize cellular metabolic homeostasis, as exemplified in diverse cancers where disruption or deregulation of DNA repair pathways results in genome instability. Because routinely used biological, physical and chemical agents impact human health, testing their genotoxicity and regulating their use have become important. In this introductory review, we will delineate mechanisms of DNA damage and the counteracting repair/tolerance pathways to provide insights into the molecular basis of genotoxicity in cells that lays the foundation for subsequent articles in this issue. Environ. Mol. Mutagen. 58:235-263, 2017. © 2017 Wiley Periodicals, Inc.
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9
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Pellegrino S, Altmeyer M. Interplay between Ubiquitin, SUMO, and Poly(ADP-Ribose) in the Cellular Response to Genotoxic Stress. Front Genet 2016; 7:63. [PMID: 27148359 PMCID: PMC4835507 DOI: 10.3389/fgene.2016.00063] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 04/04/2016] [Indexed: 01/13/2023] Open
Abstract
Cells employ a complex network of molecular pathways to cope with endogenous and exogenous genotoxic stress. This multilayered response ensures that genomic lesions are efficiently detected and faithfully repaired in order to safeguard genome integrity. The molecular choreography at sites of DNA damage relies heavily on post-translational modifications (PTMs). Protein modifications with ubiquitin and the small ubiquitin-like modifier SUMO have recently emerged as important regulatory means to coordinate DNA damage signaling and repair. Both ubiquitylation and SUMOylation can lead to extensive chain-like protein modifications, a feature that is shared with yet another DNA damage-induced PTM, the modification of proteins with poly(ADP-ribose) (PAR). Chains of ubiquitin, SUMO, and PAR all contribute to the multi-protein assemblies found at sites of DNA damage and regulate their spatio-temporal dynamics. Here, we review recent advancements in our understanding of how ubiquitin, SUMO, and PAR coordinate the DNA damage response and highlight emerging examples of an intricate interplay between these chain-like modifications during the cellular response to genotoxic stress.
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Affiliation(s)
| | - Matthias Altmeyer
- Department of Molecular Mechanisms of Disease, University of ZurichZürich, Switzerland
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10
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Somyajit K, Saxena S, Babu S, Mishra A, Nagaraju G. Mammalian RAD51 paralogs protect nascent DNA at stalled forks and mediate replication restart. Nucleic Acids Res 2015; 43:9835-55. [PMID: 26354865 PMCID: PMC4787763 DOI: 10.1093/nar/gkv880] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 08/23/2015] [Indexed: 12/22/2022] Open
Abstract
Mammalian RAD51 paralogs are implicated in the repair of collapsed replication forks by homologous recombination. However, their physiological roles in replication fork maintenance prior to fork collapse remain obscure. Here, we report on the role of RAD51 paralogs in short-term replicative stress devoid of DSBs. We show that RAD51 paralogs localize to nascent DNA and common fragile sites upon replication fork stalling. Strikingly, RAD51 paralogs deficient cells exhibit elevated levels of 53BP1 nuclear bodies and increased DSB formation, the latter being attributed to extensive degradation of nascent DNA at stalled forks. RAD51C and XRCC3 promote the restart of stalled replication in an ATP hydrolysis dependent manner by disengaging RAD51 and other RAD51 paralogs from the halted forks. Notably, we find that Fanconi anemia (FA)-like disorder and breast and ovarian cancer patient derived mutations of RAD51C fails to protect replication fork, exhibit under-replicated genomic regions and elevated micro-nucleation. Taken together, RAD51 paralogs prevent degradation of stalled forks and promote the restart of halted replication to avoid replication fork collapse, thereby maintaining genomic integrity and suppressing tumorigenesis.
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Affiliation(s)
- Kumar Somyajit
- Department of Biochemistry, Indian Institute of Science, Bangalore-560012, India
| | - Sneha Saxena
- Department of Biochemistry, Indian Institute of Science, Bangalore-560012, India
| | - Sharath Babu
- Department of Biochemistry, Indian Institute of Science, Bangalore-560012, India
| | - Anup Mishra
- Department of Biochemistry, Indian Institute of Science, Bangalore-560012, India
| | - Ganesh Nagaraju
- Department of Biochemistry, Indian Institute of Science, Bangalore-560012, India
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11
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Altmeyer M, Neelsen KJ, Teloni F, Pozdnyakova I, Pellegrino S, Grøfte M, Rask MBD, Streicher W, Jungmichel S, Nielsen ML, Lukas J. Liquid demixing of intrinsically disordered proteins is seeded by poly(ADP-ribose). Nat Commun 2015; 6:8088. [PMID: 26286827 PMCID: PMC4560800 DOI: 10.1038/ncomms9088] [Citation(s) in RCA: 390] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 07/16/2015] [Indexed: 01/01/2023] Open
Abstract
Intrinsically disordered proteins can phase separate from the soluble intracellular space, and tend to aggregate under pathological conditions. The physiological functions and molecular triggers of liquid demixing by phase separation are not well understood. Here we show in vitro and in vivo that the nucleic acid-mimicking biopolymer poly(ADP-ribose) (PAR) nucleates intracellular liquid demixing. PAR levels are markedly induced at sites of DNA damage, and we provide evidence that PAR-seeded liquid demixing results in rapid, yet transient and fully reversible assembly of various intrinsically disordered proteins at DNA break sites. Demixing, which relies on electrostatic interactions between positively charged RGG repeats and negatively charged PAR, is amplified by aggregation-prone prion-like domains, and orchestrates the earliest cellular responses to DNA breakage. We propose that PAR-seeded liquid demixing is a general mechanism to dynamically reorganize the soluble nuclear space with implications for pathological protein aggregation caused by derailed phase separation.
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Affiliation(s)
- Matthias Altmeyer
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, Copenhagen DK-2200, Denmark.,Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Winterthurerstrasse 190, Zurich CH-8057, Switzerland
| | - Kai J Neelsen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, Copenhagen DK-2200, Denmark
| | - Federico Teloni
- Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Winterthurerstrasse 190, Zurich CH-8057, Switzerland
| | - Irina Pozdnyakova
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, Copenhagen DK-2200, Denmark
| | - Stefania Pellegrino
- Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Winterthurerstrasse 190, Zurich CH-8057, Switzerland
| | - Merete Grøfte
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, Copenhagen DK-2200, Denmark
| | - Maj-Britt Druedahl Rask
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, Copenhagen DK-2200, Denmark
| | - Werner Streicher
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, Copenhagen DK-2200, Denmark
| | - Stephanie Jungmichel
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, Copenhagen DK-2200, Denmark
| | - Michael Lund Nielsen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, Copenhagen DK-2200, Denmark
| | - Jiri Lukas
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, Copenhagen DK-2200, Denmark
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12
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Khurana S, Kruhlak MJ, Kim J, Tran AD, Liu J, Nyswaner K, Shi L, Jailwala P, Sung MH, Hakim O, Oberdoerffer P. A macrohistone variant links dynamic chromatin compaction to BRCA1-dependent genome maintenance. Cell Rep 2014; 8:1049-62. [PMID: 25131201 PMCID: PMC4154351 DOI: 10.1016/j.celrep.2014.07.024] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 04/28/2014] [Accepted: 07/16/2014] [Indexed: 02/07/2023] Open
Abstract
Appropriate DNA double-strand break (DSB) repair factor choice is essential for ensuring accurate repair outcome and genomic integrity. The factors that regulate this process remain poorly understood. Here, we identify two repressive chromatin components, the macrohistone variant macroH2A1 and the H3K9 methyltransferase and tumor suppressor PRDM2, which together direct the choice between the antagonistic DSB repair mediators BRCA1 and 53BP1. The macroH2A1/PRDM2 module mediates an unexpected shift from accessible to condensed chromatin that requires the ataxia telangiectasia mutated (ATM)-dependent accumulation of both proteins at DSBs in order to promote DSB-flanking H3K9 dimethylation. Remarkably, loss of macroH2A1 or PRDM2, as well as experimentally induced chromatin decondensation, impairs the retention of BRCA1, but not 53BP1, at DSBs. As a result, mac-roH2A1 and/or PRDM2 depletion causes epistatic defects in DSB end resection, homology-directed repair, and the resistance to poly(ADP-ribose) polymerase (PARP) inhibition—all hallmarks of BRCA1-deficient tumors. Together, these findings identify dynamic, DSB-associated chromatin reorganization as a critical modulator of BRCA1-dependent genome maintenance.
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Affiliation(s)
- Simran Khurana
- Laboratory of Receptor Biology and Gene Expression, NCI/NIH, Bethesda, MD 20892, USA
| | | | - Jeongkyu Kim
- Laboratory of Receptor Biology and Gene Expression, NCI/NIH, Bethesda, MD 20892, USA
| | - Andy D Tran
- Laboratory of Receptor Biology and Gene Expression, NCI/NIH, Bethesda, MD 20892, USA
| | - Jinping Liu
- Laboratory of Receptor Biology and Gene Expression, NCI/NIH, Bethesda, MD 20892, USA
| | | | - Lei Shi
- Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin 300070, China
| | - Parthav Jailwala
- Advanced Biomedical Computing Center, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702, USA
| | - Myong-Hee Sung
- Laboratory of Receptor Biology and Gene Expression, NCI/NIH, Bethesda, MD 20892, USA
| | - Ofir Hakim
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Philipp Oberdoerffer
- Laboratory of Receptor Biology and Gene Expression, NCI/NIH, Bethesda, MD 20892, USA.
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13
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Panier S, Durocher D. Push back to respond better: regulatory inhibition of the DNA double-strand break response. Nat Rev Mol Cell Biol 2013; 14:661-72. [PMID: 24002223 DOI: 10.1038/nrm3659] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Single DNA lesions such as DNA double-strand breaks (DSBs) can cause cell death or trigger genome rearrangements that have oncogenic potential, and so the pathways that mend and signal DNA damage must be highly sensitive but, at the same time, selective and reversible. When initiated, boundaries must be set to restrict the DSB response to the site of the lesion. The integration of positive and, crucially, negative control points involving post-translational modifications such as phosphorylation, ubiquitylation and acetylation is key for building fast, effective responses to DNA damage and for mitigating the impact of DNA lesions on genome integrity.
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Affiliation(s)
- Stephanie Panier
- 1] The Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada. [2] Present address: DNA Damage Response Laboratory, London Research Institute, Cancer Research UK, Clare Hall, South Mimms, London EN6 3LD, UK
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