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Haykal MM, Rodrigues-Ferreira S, El Botty R, Sourd L, Marangoni E, Varin M, Denis A, Nahmias C. Targeting WEE1 kinase as a therapeutic strategy in ATIP3-deficient breast cancers. Cancer Lett 2025; 620:217665. [PMID: 40127815 DOI: 10.1016/j.canlet.2025.217665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2025] [Revised: 03/04/2025] [Accepted: 03/21/2025] [Indexed: 03/26/2025]
Abstract
ATIP3-deficient breast cancers represent a subset of aggressive tumors with limited therapeutic options and poor prognosis. Here, we screened a panel of cell cycle kinase inhibitors to identify novel targets for these tumors. We show that loss of ATIP3 sensitizes breast cancer cells to WEE1 inhibition, resulting in aberrant mitoses characterized by detachment of centromere proteins from DNA and chromosome pulverization. This phenotype arises from excessive replication stress and DNA damage in S-phase, combined with premature mitotic entry driven by untimely CDK1 activation. Mechanistically, we identify DNA2 helicase/nuclease as a key mediator of chromosome pulverization. Importantly, the heightened sensitivity of ATIP3-deficient cells to WEE1 inhibition provides a strong rationale for clinical exploration of WEE1-targeted therapies. Furthermore, combining WEE1 and PKMYT1 inhibitors enhances therapeutic efficacy, offering a promising strategy for personalized treatment in ATIP3-deficient breast cancers.
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Affiliation(s)
- Maria M Haykal
- Institut Gustave Roussy, Inserm U981, Biomarqueurs prédictifs et Nouvelles Stratégies Thérapeutiques en Oncologie, 94800, Villejuif, France; Université Paris-Saclay, 91400, Orsay, France
| | - Sylvie Rodrigues-Ferreira
- Institut Gustave Roussy, Inserm U981, Biomarqueurs prédictifs et Nouvelles Stratégies Thérapeutiques en Oncologie, 94800, Villejuif, France; Université Paris-Saclay, 91400, Orsay, France; Inovarion, 75005, Paris, France
| | - Rania El Botty
- Translational Research Department, Institut Curie, PSL University, 75005, Paris, France
| | - Laura Sourd
- Translational Research Department, Institut Curie, PSL University, 75005, Paris, France
| | - Elisabetta Marangoni
- Translational Research Department, Institut Curie, PSL University, 75005, Paris, France
| | | | | | - Clara Nahmias
- Institut Gustave Roussy, Inserm U981, Biomarqueurs prédictifs et Nouvelles Stratégies Thérapeutiques en Oncologie, 94800, Villejuif, France; Université Paris-Saclay, 91400, Orsay, France.
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2
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Ingham A, Ramaswami M, Ramangoudr-Bhojappa R, Pladevall-Morera D, De Santis F, Terriente J, Muñoz IM, Rouse J, Chandrasekharappa SC, Lopez-Contreras AJ. Loss of SLX4IP leads to Common Fragile Sites instability and compromises DNA interstrand crosslink repair in vivo. J Biol Chem 2025:110244. [PMID: 40383148 DOI: 10.1016/j.jbc.2025.110244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2024] [Revised: 05/05/2025] [Accepted: 05/13/2025] [Indexed: 05/20/2025] Open
Abstract
Common Fragile Sites (CFSs) are chromosomal loci with inherent characteristics that make them difficult to fully replicate thus rendering them vulnerable to replication stress (RS). Under-replicated CFSs manifests as cytogenetic gaps and breaks on metaphase chromosomes. Moreover, CFSs are hotspots for tumorigenic chromosomal rearrangements. The Fanconi anemia (FA) pathway is at the core of a network of proteins that works to safeguard CFSs during replication and RS. Here, we uncover a novel role of SLX4IP in maintaining CFS stability. We show that SLX4IP localizes to stressed CFSs and that its loss exacerbates genome instability, including CFS expression. Furthermore, direct SLX4IP depletion leads to impaired replication and growth deficiencies. SLX4IP and FANCP/SLX4 are epistatic, suggesting that SLX4IP acts with SLX4 to maintain CFS stability. Finally, zebrafish larvae with homozygous knockout of slx4ip gene showed higher frequency of embryonic anomalies and sensitivity to DNA crosslinking agent, a typical cellular characteristic of FA patients. Our results establish a causal link between SLX4IP deficiency and chromosomal instability, which may explain how SLX4IP dysregulation contributes to cancer development.
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Affiliation(s)
- Andreas Ingham
- Department of Cellular and Molecular Medicine, Center for Chromosome Stability and Center for Healthy Aging, University of Copenhagen, Copenhagen 2200, Denmark
| | - Mukundhan Ramaswami
- Cancer Genomics Unit, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ramanagouda Ramangoudr-Bhojappa
- Cancer Genomics Unit, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - David Pladevall-Morera
- Department of Cellular and Molecular Medicine, Center for Chromosome Stability and Center for Healthy Aging, University of Copenhagen, Copenhagen 2200, Denmark
| | - Flavia De Santis
- ZeClinics SL, Carretera de Can Ruti, Camí de les Escoles, s/n, Edificio IGTP Muntanya, Badalona, 08916 Barcelona, Spain
| | - Javier Terriente
- ZeClinics SL, Carretera de Can Ruti, Camí de les Escoles, s/n, Edificio IGTP Muntanya, Badalona, 08916 Barcelona, Spain
| | - Ivan M Muñoz
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - John Rouse
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Settara C Chandrasekharappa
- Cancer Genomics Unit, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Andres J Lopez-Contreras
- Department of Cellular and Molecular Medicine, Center for Chromosome Stability and Center for Healthy Aging, University of Copenhagen, Copenhagen 2200, Denmark; Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Sevilla, Universidad Pablo de Olavide, Sevilla 41092, Spain.
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3
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Singh MI, Rajendraprasad G, Katopodis V, Cui R, Barisic M, Bhowmick R, Hickson ID. Mechanistic insight into anaphase bridge signaling to the abscission checkpoint. EMBO J 2025:10.1038/s44318-025-00453-w. [PMID: 40355560 DOI: 10.1038/s44318-025-00453-w] [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: 02/05/2024] [Revised: 04/16/2025] [Accepted: 04/24/2025] [Indexed: 05/14/2025] Open
Abstract
During cytokinesis in human cells, a failure to resolve persistent DNA bridges that span the cell-division plane maintains the Aurora B-dependent abscission checkpoint in an active state. However, the molecular mechanism by which unresolved sister-chromatid bridging signals to this checkpoint is poorly defined. Here, we define an essential role for the Bloom's syndrome helicase, BLM, in signaling to the abscission-checkpoint machinery in response to replication stress through the conversion of dsDNA bridges into RPA-coated ssDNA. RPA then promotes ATR-CHK1 signaling to Aurora B, utilizing a kinase cascade shared with the S-phase checkpoint. BLM-deficient cells ultimately abandon cytokinesis in response to replication stress, which promotes binucleation and hence aneuploidy. Considering that aneuploidy is a hallmark of cancer, we propose that this role for BLM in cytokinesis is a plausible reason for cancer predisposition in Bloom's syndrome individuals. Consistent with this, BLM deficiency promotes anchorage-independent growth of non-cancer cells.
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Affiliation(s)
- Manika I Singh
- Center for Chromosome Stability, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
- Centre for Genomic Medicine, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Girish Rajendraprasad
- Danish Cancer Society Research Center, Strandboulevarden 49, 2100, Copenhagen N, Denmark
| | - Vasileios Katopodis
- Danish Cancer Society Research Center, Strandboulevarden 49, 2100, Copenhagen N, Denmark
| | - Rui Cui
- Center for Chromosome Stability, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Marin Barisic
- Danish Cancer Society Research Center, Strandboulevarden 49, 2100, Copenhagen N, Denmark
- Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Rahul Bhowmick
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA.
| | - Ian D Hickson
- Center for Chromosome Stability, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark.
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4
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Kharlamova MA, Kushwah MS, Jachowski TJ, Subramaniam S, Schiff V, Stewart AF, Kukura P, Schäffer E. Monomers and short oligomers of human RAD52 promote single-strand annealing. Proc Natl Acad Sci U S A 2025; 122:e2420771122. [PMID: 40184180 PMCID: PMC12002259 DOI: 10.1073/pnas.2420771122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2024] [Accepted: 02/25/2025] [Indexed: 04/05/2025] Open
Abstract
Genome maintenance and stability rely on the repair of DNA double-strand breaks. Breaks can be repaired via the single-strand-annealing pathway mediated by the protein RAD52. RAD52 oligomerizes to rings that are thought to promote annealing. However, rings have only been observed at micromolar concentrations at which annealing activity is impaired. Thus, it is unclear which oligomeric form is responsible for annealing. We combined single-molecule mass photometry with biochemical assays to determine the in vitro oligomeric states of human RAD52. We found that RAD52 was mostly monomeric at lower nanomolar concentrations. With increasing concentration, RAD52 oligomerized and formed rings with a variable stoichiometry from heptamers to tridecamers consistent with an oligomerization model of noncooperative assembly coupled with preferential cyclization. Under conditions where hardly any rings were present, RAD52 already promoted single-strand annealing in vitro. Our findings indicate that in vitro single-strand annealing can be mediated by monomers and short oligomers of RAD52. The oligomerization model suggests that ring formation is similar to a phase transition whereby rings are a reservoir to replenish the monomer and short oligomer pool. This pool has a nearly constant concentration which may be optimal for annealing and would be independent, for example, of the amount of DNA damage, protein upregulation, or the cell cycle.
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Affiliation(s)
- Maria A. Kharlamova
- Cellular Nanoscience, Center for Plant Molecular Biology, University of Tübingen, Tübingen72076, Germany
| | - Manish S. Kushwah
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, OxfordOX1 3QZ, United Kingdom
| | - Tobias J. Jachowski
- Cellular Nanoscience, Center for Plant Molecular Biology, University of Tübingen, Tübingen72076, Germany
| | - Sivaraman Subramaniam
- Genomics, Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Dresden01307, Germany
| | - Viktor Schiff
- Cellular Nanoscience, Center for Plant Molecular Biology, University of Tübingen, Tübingen72076, Germany
| | - A. Francis Stewart
- Genomics, Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Dresden01307, Germany
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney2052, NSW, Australia
- State Key Laboratory of Microbial Research, Shandong University, Qingdao266237, China
| | - Philipp Kukura
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, OxfordOX1 3QZ, United Kingdom
| | - Erik Schäffer
- Cellular Nanoscience, Center for Plant Molecular Biology, University of Tübingen, Tübingen72076, Germany
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5
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Shiomi Y, Hayashi A, Saito Y, Kanemaki MT, Nishitani H. The Depletion of TRAIP Results in the Retention of PCNA on Chromatin During Mitosis Leads to Inhibiting DNA Replication Initiation. Genes Cells 2025; 30:e70006. [PMID: 39956965 DOI: 10.1111/gtc.70006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 01/17/2025] [Accepted: 01/29/2025] [Indexed: 02/18/2025]
Abstract
Loading PCNA onto chromatin is a pivotal step in DNA replication, cell cycle progression, and genome integrity. Conversely, unloading PCNA from chromatin is equally crucial for maintaining genome stability. Cells deficient in the PCNA unloader ATAD5-RFC exhibit elevated levels of chromatin-bound PCNA during S phase, but still show dissociation of PCNA from chromatin in mitosis. In this study, we found that depletion of TRAIP, an E3 ubiquitin ligase, results in the retention of PCNA on chromatin during mitosis. Although TRAIP-depleted cells with chromatin-bound PCNA during mitosis progressed into the subsequent G1 phase, they displayed reduced levels of Cdt1, a key replication licensing factor, and impaired S phase entry. In addition, TRAIP-depleted cells exhibited delayed S phase progression. These results suggest that TRAIP functions independently of ATAD5-RFC in removing PCNA from chromatin. Furthermore, TRAIP appears to be essential for precise pre-replication complexes (pre-RCs) formation necessary for faithful initiation of DNA replication and S phase progression.
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Affiliation(s)
- Yasushi Shiomi
- Graduate School of Science, University of Hyogo, Kamigori, Japan
| | - Akiyo Hayashi
- Graduate School of Science, University of Hyogo, Kamigori, Japan
| | - Yuichiro Saito
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Shizuoka, Japan
| | - Masato T Kanemaki
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Shizuoka, Japan
- Department of Advanced Studies, The Graduate University for Advanced Studies (SOKENDAI), Shizuoka, Japan
- Department of Biological Science, The University of Tokyo, Tokyo, Japan
| | - Hideo Nishitani
- Graduate School of Science, University of Hyogo, Kamigori, Japan
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6
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Hayward BE, Kim GY, Miller CJ, McCann C, Lowery MG, Wood RD, Usdin K. Repeat expansion in a fragile X model is independent of double strand break repair mediated by Pol θ, RAD52, RAD54 or RAD54B. Sci Rep 2025; 15:5033. [PMID: 39934227 PMCID: PMC11814403 DOI: 10.1038/s41598-025-87541-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2024] [Accepted: 01/20/2025] [Indexed: 02/13/2025] Open
Abstract
Microsatellite instability is responsible for the human repeat expansion diseases (REDs). The mutagenic process differs from classical cancer-associated microsatellite instability (MSI) in that it requires the mismatch repair proteins that normally protect against MSI. LIG4, an enzyme essential for non-homologous end-joining (NHEJ), the major pathway for double-strand break repair (DSBR) in mammalian cells, protects against expansion in mouse models. Thus, NHEJ may compete with the expansion pathway for access to a common intermediate. This raises the possibility that expansion involves an NHEJ-independent form of DSBR. Pol θ, a polymerase involved in the theta-mediated end joining (TMEJ) DSBR pathway, has been proposed to play a role in repeat expansion. Here we examine the effect of the loss of Pol θ on expansion in FXD mouse embryonic stem cells (mESCs), along with the effects of mutations in Rad52, Rad54l and Rad54b, genes important for multiple DSBR pathways. None of these mutations significantly affected repeat expansion. These observations put major constraints on what pathways are likely to drive expansion. Together with our previous demonstration of the protective effect of nucleases like EXO1 and FAN1, and the importance of Pol β, they suggest a plausible model for late steps in the expansion process.
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Affiliation(s)
- Bruce E Hayward
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Geum-Yi Kim
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Carson J Miller
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Cai McCann
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Megan G Lowery
- Department of Epigenetics & Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, PO Box 301429, Unit 1951, Houston, TX, 77230, USA
| | - Richard D Wood
- Department of Epigenetics & Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, PO Box 301429, Unit 1951, Houston, TX, 77230, USA
| | - Karen Usdin
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
- National Institutes of Health, 8 Center Drive MSC 0830, Building 8, Room 2A19, Bethesda, MD, USA.
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7
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Sparr C, Meitinger F. Prolonged mitosis: A key indicator for detecting stressed and damaged cells. Curr Opin Cell Biol 2025; 92:102449. [PMID: 39721293 DOI: 10.1016/j.ceb.2024.102449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2024] [Revised: 11/24/2024] [Accepted: 11/26/2024] [Indexed: 12/28/2024]
Abstract
During mitosis, chromosomes condense, align to form a metaphase plate and segregate to the two daughter cells. Mitosis is one of the most complex recurring transformations in the life of a cell and requires a high degree of reliability to ensure the error-free transmission of genetic information to the next cell generation. An abnormally prolonged mitosis indicates potential defects that compromise genomic integrity. The mitotic stopwatch pathway detects even moderately prolonged mitoses by integrating memories of mitotic durations, ultimately leading to p53-mediated cell cycle arrest or death. This mechanism competes with mitogen signaling to stop the proliferation of damaged and potentially dangerous cells at a pre-oncogenic stage. Mitosis is a highly vulnerable phase, which is affected by multiple types of cellular damages and diverse stresses. We discuss the hypothesis that the duration of mitosis serves as an indicator of cell health.
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Affiliation(s)
- Carmen Sparr
- Okinawa Institute of Science and Technology Graduate University, Okinawa 904-0495, Japan
| | - Franz Meitinger
- Okinawa Institute of Science and Technology Graduate University, Okinawa 904-0495, Japan.
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8
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Lee J, Choi E, Kim H, Kim YJ, Kim SH. NELL2- PAX7 Transcriptional Cascade Suggests Activation Mechanism for RAD52-Dependent Alternative Lengthening of Telomeres During Malignant Transformation of Malignant Peripheral Nerve Sheath Tumors: Elongation of Telomeres and Poor Survival. Biomedicines 2025; 13:281. [PMID: 40002695 PMCID: PMC11853032 DOI: 10.3390/biomedicines13020281] [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: 11/25/2024] [Revised: 01/22/2025] [Accepted: 01/22/2025] [Indexed: 02/27/2025] Open
Abstract
Background: In eukaryotes with a double-stranded linear DNA genome, the loss of terminal DNA during replication is inevitable due to an end-replication problem; here, telomeres serve as a buffer against DNA loss. Thus, the activation of the telomere maintenance mechanism (TMM) is a prerequisite for malignant transformation. Methods: We compared neurofibroma (NF, benign) and malignant peripheral nerve sheath tumors (MPNSTs) occurring in the same patient with type 1 neurofibromatosis, where each NF-MPNST pair shared the same genetic background and differentiation lineage; this minimizes the genetic bias and contrasts only those changes that are related to malignant transformation. A total of 20 NF-MPNST pairs from 20 NF1 patients were analyzed. Whole-transcriptome sequencing (WTS) was conducted to profile the transcriptional relationship, and whole-genome sequencing (WGS) was performed to measure the telomere length. Results: We identified 22 differentially expressed genes (DEGs) during the malignant transformation of MPNSTs. Among them, NELL2 activated PAX7, which sequentially activated RAD52, the recombinase of RAD52-dependent alternative lengthening of telomeres (ALT). RAD52 elongated MPNSTs-telomeres (p = 0.017). Otherwise, neither NELL2 nor PAX7 affected telomere length (p = 0.647 and p = 0.354, respectively). RAD52 increased MPNSTs-telomeres length, independently of NELL2 and PAX7 in multiple analyses (p = 0.021). The group with increased telomere length during the malignant transformation showed inferior overall survival (OS) (HR = 3.809, p = 0.038) to the group without increased telomere length. Accordingly, the group with increased PAX7 showed inferior OS (HR = 4.896, p = 0.046) and metastasis-free survival (MFS) (HR = 9.129, p = 0.007) in comparison to the group without increased PAX7; the group with increased RAD52 showed inferior MFS (HR = 8.669, p = 0.011) in comparison to the group without increased RAD52. Conclusions: We suggest that the NELL2-PAX7 transcriptional cascade activates RAD52-dependent ALT to increase telomere length during the malignant transformation of MPNSTs, resulting in a poor prognosis.
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Affiliation(s)
- Jungwoo Lee
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, The Graduate School, Yonsei University, Seoul 03722, Republic of Korea; (J.L.); (E.C.); (H.K.); (Y.-J.K.)
| | - Eunji Choi
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, The Graduate School, Yonsei University, Seoul 03722, Republic of Korea; (J.L.); (E.C.); (H.K.); (Y.-J.K.)
| | - Hyoju Kim
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, The Graduate School, Yonsei University, Seoul 03722, Republic of Korea; (J.L.); (E.C.); (H.K.); (Y.-J.K.)
| | - Young-Joon Kim
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, The Graduate School, Yonsei University, Seoul 03722, Republic of Korea; (J.L.); (E.C.); (H.K.); (Y.-J.K.)
| | - Seung Hyun Kim
- Department of Orthopaedic Surgery, Yonsei University College of Medicine, 50-1, Yonsei-Ro, Seodaemun-gu, Seoul 03722, Republic of Korea
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9
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Lee C, Oh JS. Novel BRCA1-PLK1-CIP2A axis orchestrates homologous recombination-mediated DNA repair to maintain chromosome integrity during oocyte meiosis. Nucleic Acids Res 2025; 53:gkae1207. [PMID: 39657788 PMCID: PMC11754672 DOI: 10.1093/nar/gkae1207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 11/18/2024] [Accepted: 11/21/2024] [Indexed: 12/12/2024] Open
Abstract
Double-strand breaks (DSBs) are a formidable threat to genome integrity, potentially leading to cancer and various genetic diseases. The prolonged lifespan of mammalian oocytes increases their susceptibility to DNA damage over time. While somatic cells suppress DSB repair during mitosis, oocytes exhibit a remarkable capacity to repair DSBs during meiotic maturation. However, the precise mechanisms underlying DSB repair in oocytes remain poorly understood. Here, we describe the pivotal role of the BRCA1-PLK1-CIP2A axis in safeguarding genomic integrity during meiotic maturation in oocytes. We found that inhibition of homologous recombination (HR) severely impaired chromosome integrity by generating chromosome fragments during meiotic maturation. Notably, HR inhibition impaired the recruitment of CIP2A to damaged chromosomes, and the depletion of CIP2A led to chromosome fragmentation following DSB induction. Moreover, BRCA1 depletion impaired chromosomal recruitment of CIP2A, but not vice versa. Importantly, the impaired chromosomal recruitment of CIP2A could be rescued by PLK1 inhibition. Consequently, our findings not only underscore the importance of the chromosomal recruitment of CIP2A in preventing chromosome fragmentation, but also demonstrate the regulatory role of the BRCA1-PLK1-CIP2A axis in this process during oocyte meiotic maturation.
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Affiliation(s)
- Crystal Lee
- Department of Integrative Biotechnology, Sungkyunkwan University, 2066 Seobu-ro, Suwon 16419, South Korea
| | - Jeong Su Oh
- Department of Integrative Biotechnology, Sungkyunkwan University, 2066 Seobu-ro, Suwon 16419, South Korea
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10
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Niljikar M, Barreto-Galvez A, Patel S, Gagliardi JE, Kumar V, Pradeep A, Juwarwala A, Gerhardt J, Chang Y, Montagna C, Madireddy A. Polymerase Eta Recruits FANCD2 to Common Fragile Sites to Maintain Genome Stability. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.01.06.631600. [PMID: 39829787 PMCID: PMC11741286 DOI: 10.1101/2025.01.06.631600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2025]
Abstract
The replicative polymerase delta is inefficient copying repetitive DNA sequences. Error-prone translesion polymerases have been shown to switch with high-fidelity replicative polymerases to help navigate repetitive DNA. We and others have demonstrated the importance of one such translesion polymerase, polymerase Eta (pol eta), in facilitating replication at genomic regions called common fragile sites (CFS), which are difficult-to-replicate genomic regions that are hypersensitive to replication stress. However, the mechanistic basis for pol eta's role in facilitating DNA replication at CFS and(or) at other genomic regions is currently unclear. Importantly, the functional importance of three non-catalytic domains of pol eta, the Ubiquitin-binding Zinc finger (UBZ), PCNA interacting protein (PIP) domain, and the F1 domain which mediates its switch with replicative DNA polymerases in mediating replication stress, especially at CFS loci is not clear. Here, we report that the PIP and UBZ domains of Pol Eta are both critical for its role in mediating cellular replication stress, especially at CFS. The absence of either domain induced elevated replication stress, replication stalling and DNA damage accumulation genome wide. This effect was even more pronounced at CFS loci leading to the accumulation of under replication DNA in G2/M. Importantly, while the inactivation of the UBZ domain resulted in a robust FANCD2 monoubiquitylation (a prominent marker of FANCD2 activation), FANCD2 recruitment genome wide was significantly impacted, especially at CFSs such as FRA16D. These S-phase phenotypes result in ssDNA gap formation and the persistence of under-replicated genomic regions upon transition to G2/M. While post-replicative gap filing/ repair by Mitotic DNA synthesis is activated in the mutants, it only effectively resolves UFBs in the F1* cells. The PIP*, UBZ* and pol eta -/- cells unfortunately manifest excessive toxic cytosolic DNA that instigates a strong innate immune response. These results collectively show that translesion polymerase Eta functions in a common pathway with FANCD2 to prevent replication perturbation and instability at CFS loci.
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11
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Xu Y, Morrow CA, Laksir Y, Holt OM, Taylor K, Tsiappourdhi C, Collins P, Jia S, Andreadis C, Whitby MC. DNA nicks in both leading and lagging strand templates can trigger break-induced replication. Mol Cell 2025; 85:91-106.e5. [PMID: 39561776 PMCID: PMC12095120 DOI: 10.1016/j.molcel.2024.10.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 09/09/2024] [Accepted: 10/22/2024] [Indexed: 11/21/2024]
Abstract
Encounters between replication forks and unrepaired DNA single-strand breaks (SSBs) can generate both single-ended and double-ended double-strand breaks (seDSBs and deDSBs). seDSBs can be repaired by break-induced replication (BIR), which is a highly mutagenic pathway that is thought to be responsible for many of the mutations and genome rearrangements that drive cancer development. However, the frequency of BIR's deployment and its ability to be triggered by both leading and lagging template strand SSBs were unclear. Using site- and strand-specific SSBs generated by nicking enzymes, including CRISPR-Cas9 nickase (Cas9n), we demonstrate that leading and lagging template strand SSBs in fission yeast are typically converted into deDSBs that are repaired by homologous recombination. However, both types of SSBs can also trigger BIR, and the frequency of these events increases when fork convergence is delayed and the non-homologous end joining protein Ku70 is deleted.
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Affiliation(s)
- Yuanlin Xu
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Carl A Morrow
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Yassine Laksir
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Orla M Holt
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Kezia Taylor
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Costas Tsiappourdhi
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Patrick Collins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Su Jia
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Christos Andreadis
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Matthew C Whitby
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
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12
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Basto C, Moreira-Tavares E, Muhammad AA, Baconnais S, Mazón G, Le Cam E, Dupaigne P. Homologous Recombination and DNA Intermediates Analyzed by Electron Microscopy. Methods Mol Biol 2025; 2881:239-257. [PMID: 39704947 DOI: 10.1007/978-1-0716-4280-1_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2024]
Abstract
Homologous recombination (HR) is a high-fidelity DNA repair pathway that uses a homologous DNA sequence as a template. Recombinase proteins are the central HR players in the three kingdoms of life. RecA/RadA/Rad51 assemble on ssDNA, generated after the processing of double-strand breaks or stalled replication forks into an active and dynamic presynaptic helical nucleofilament. Presynaptic filament formation is regulated by a series of partners of the recombinase, such as scRad52/hBRCA2 mediators or anti-recombinase proteins, to form an active machinery involved in homology search, pair-matching, and invasion within homologous sequences. During homology search, but also during strand invasion, the multiprotein complexes that form the nucleofilament induce the formation of a variety of DNA intermediate states. Here we present specific approaches to study and characterize the different DNA and DNA-protein intermediates formed during homologous recombination. The combination of powerful electron microscopy and sample preparation methods provides a better understanding of these proteins' molecular activity and their interactions.
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Affiliation(s)
- Clara Basto
- Genome Integrity and Cancers, UMR 9019 CNRS, Université-Paris-Saclay, Gustave Roussy, Villejuif, France
| | - Eliana Moreira-Tavares
- Genome Integrity and Cancers, UMR 9019 CNRS, Université-Paris-Saclay, Gustave Roussy, Villejuif, France
| | - Ali-Akbar Muhammad
- Genome Integrity and Cancers, UMR 9019 CNRS, Université-Paris-Saclay, Gustave Roussy, Villejuif, France
| | - Sonia Baconnais
- Genome Integrity and Cancers, UMR 9019 CNRS, Université-Paris-Saclay, Gustave Roussy, Villejuif, France
| | - Gerard Mazón
- Genome Integrity and Cancers, UMR 9019 CNRS, Université-Paris-Saclay, Gustave Roussy, Villejuif, France
| | - Eric Le Cam
- Genome Integrity and Cancers, UMR 9019 CNRS, Université-Paris-Saclay, Gustave Roussy, Villejuif, France.
| | - Pauline Dupaigne
- Genome Integrity and Cancers, UMR 9019 CNRS, Université-Paris-Saclay, Gustave Roussy, Villejuif, France.
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13
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Scully R, Glodzik D, Menghi F, Liu ET, Zhang CZ. Mechanisms of tandem duplication in the cancer genome. DNA Repair (Amst) 2025; 145:103802. [PMID: 39742573 PMCID: PMC11843477 DOI: 10.1016/j.dnarep.2024.103802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2024] [Revised: 12/17/2024] [Accepted: 12/17/2024] [Indexed: 01/03/2025]
Abstract
Tandem duplications (TD) are among the most frequent type of structural variant (SV) in the cancer genome. They are characterized by a single breakpoint junction that defines the boundaries and the size of the duplicated segment. Cancer-associated TDs often increase oncogene copy number or disrupt tumor suppressor gene function, and thus have important roles in tumor evolution. TDs in cancer genomes fall into three classes, defined by the size of duplications, and are associated with distinct genetic drivers. In this review, we survey key features of cancer-related TDs and consider possible underlying mechanisms in relation to stressed DNA replication and the 3D organization of the S phase genome.
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Affiliation(s)
- Ralph Scully
- Department of Medicine, Division of Hematology-Oncology and Cancer Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
| | - Dominik Glodzik
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Francesca Menghi
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Edison T Liu
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Cheng-Zhong Zhang
- Department of Data Science, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Department of Pathology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
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14
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Kusano Y, Kinugasa Y, Tashiro S, Hirota T. Chromosomal rearrangements associated with SMC5/6 deficiency in DNA replication. Genes Cells 2024. [PMID: 39540295 DOI: 10.1111/gtc.13180] [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: 09/27/2024] [Revised: 10/23/2024] [Accepted: 10/23/2024] [Indexed: 11/16/2024]
Abstract
Completion of DNA replication before chromosome segregation is essential for the stable maintenance of the genome. Under replication stress, DNA synthesis may persist beyond S phase, especially in genomic regions that are difficult to proceed with the replication processes. Incomplete replication in mitosis emerges as non-disjoined segment in mitotic chromosomes leading to anaphase bridges. The resulting chromosome rearrangements are not well characterized, however. Here, we report that incomplete replication due to SMC5/6 deficiency impairs sister chromatid disjunction at difficult-to-replicate regions, including common fragile sites. These non-disjoined regions manifest as cytologically defined symmetric gaps, causing anaphase bridges. These bridges break at the gaps, leading to telomere loss, micronucleation, and fragmentation. Subsequently, fusions between telomere-deficient chromosomes generate complex chromosomal rearrangements, including dicentric chromosomes, suggesting the occurrence of breakage-fusion-bridge cycle. Additionally, chromosomes in micronuclei were pulverized, indicative of chromothripsis. Our findings suggest that incomplete replication facilitates complex chromosomal rearrangements, which may contribute to genomic instability in human cancers.
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Affiliation(s)
- Yoshiharu Kusano
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
- Department of JFCR Cancer Biology, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo, Tokyo, Japan
| | - Yasuha Kinugasa
- Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - Satoshi Tashiro
- Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - Toru Hirota
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
- Department of JFCR Cancer Biology, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo, Tokyo, Japan
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15
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Hayward BE, Kim GY, Miller CJ, McCann C, Lowery MG, Wood RD, Usdin K. Repeat expansion in a Fragile X model is independent of double strand break repair mediated by Pol θ, Rad52, Rad54l or Rad54b. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.11.05.621911. [PMID: 39574643 PMCID: PMC11580960 DOI: 10.1101/2024.11.05.621911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2024]
Abstract
Microsatellite instability is responsible for the human Repeat Expansion Disorders. The mutation responsible differs from classical cancer-associated microsatellite instability (MSI) in that it requires the mismatch repair proteins that normally protect against MSI. LIG4, an enzyme essential for non-homologous end-joining (NHEJ), the major pathway for double-strand break repair (DSBR) in mammalian cells, protects against expansion in mouse models. Thus, NHEJ may compete with the expansion pathway for access to a common intermediate. This raises the possibility that expansion involves an NHEJ-independent form of DSBR. Pol θ, a polymerase involved in the theta-mediated end joining (TMEJ) DSBR pathway, has been proposed to play a role in repeat expansion. Here we examine the effect of the loss of Pol θ on expansion in FXD mouse embryonic stem cells (mESCs), along with the effects of mutations in Rad52, Rad54l and Rad54b, genes important for multiple DSBR pathways. None of these mutations significantly affected repeat expansion. These observations put major constraints on what pathways are likely to drive expansion. Together with our previous demonstration of the protective effect of nucleases like EXO1 and FAN1, and the importance of Pol β, they suggest a plausible model for late steps in the expansion process.
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Affiliation(s)
- Bruce E Hayward
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Geum-Yi Kim
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Carson J Miller
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Cai McCann
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
- Takeda Pharmaceuticals U.S.A., Inc., Global Biologics Informatics and Automation, 500 Kendall Street, Cambridge, MA 02142, USA
| | - Megan G Lowery
- The University of Texas MD Anderson Cancer Center, Department of Epigenetics & Molecular Carcinogenesis, PO Box 301429, Unit 1951, Houston, Texas 77230
| | - Richard D Wood
- The University of Texas MD Anderson Cancer Center, Department of Epigenetics & Molecular Carcinogenesis, PO Box 301429, Unit 1951, Houston, Texas 77230
| | - Karen Usdin
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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16
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Wilson TE, Ahmed S, Winningham A, Glover TW. Replication stress induces POLQ-mediated structural variant formation throughout common fragile sites after entry into mitosis. Nat Commun 2024; 15:9582. [PMID: 39505880 PMCID: PMC11541566 DOI: 10.1038/s41467-024-53917-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Accepted: 10/25/2024] [Indexed: 11/08/2024] Open
Abstract
Genomic structural variants (SVs) greatly impact human health, but much is unknown about the mechanisms that generate the largest class of nonrecurrent alterations. Common fragile sites (CFSs) are unstable loci that provide a model for SV formation, especially large deletions, under replication stress. We study SV junction formation as it occurs in human cell lines by applying error-minimized capture sequencing to CFS DNA harvested after low-dose aphidicolin treatment. SV junctions form throughout CFS genes at a 5-fold higher rate after cells pass from G2 into M-phase. Neither SV formation nor CFS expression depend on mitotic DNA synthesis (MiDAS), an error-prone form of replication active at CFSs. Instead, analysis of tens of thousands of de novo SV junctions combined with DNA repair pathway inhibition reveal a primary role for DNA polymerase theta (POLQ)-mediated end-joining (TMEJ). We propose an important role for mitotic TMEJ in nonrecurrent SV formation genome wide.
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Affiliation(s)
- Thomas E Wilson
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
| | - Samreen Ahmed
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Amanda Winningham
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Thomas W Glover
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
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17
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Choi E, Lee J, Kim H, Kim YJ, Kim SH. TGF-β superfamily-induced transcriptional activation pathways establish the RAD52-dependent ALT machinery during malignant transformation of MPNSTs. Sci Rep 2024; 14:26475. [PMID: 39488637 PMCID: PMC11531527 DOI: 10.1038/s41598-024-76732-z] [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: 06/04/2024] [Accepted: 10/16/2024] [Indexed: 11/04/2024] Open
Abstract
To study telomere maintenance mechanism (TMM) activation during malignant transformation, we compared neurofibroma (NF) and malignant peripheral nerve sheath tumor (MPNST) in the same patient with type-1 neurofibromatosis (NF1), a total of 20 NF-MPNST pairs in 20 NF1 patients. These comparisons minimized genetic bias and contrasted only changes associated with malignant transformation, while subtracting changes that developed upon the transformation of normal cells to the benign tumor. TGF-β superfamily genes were found to activate the PAX and SOX transcription factors, leading to TMM activation. BMPER activates PAX6 through BMP2 and PAX7 through BMP4; BMP15 activates SOX14; and INHBC activates PAX9 and SOX14. The activated PAX and SOX genes sequentially establish the core architecture of the RAD52-dependent alternative lengthening of telomeres (ALT). Specifically, PAX7 activates the recombinase (RAD52) and a negative regulator (SLX4IP). PAX6 and SOX14 activate positive regulators (BLM and BRCA2, respectively). PAX9 and SOX14 activate RAD9B and FEN1, which are responsible for the stability of homologous recombination intermediates and increase, together with RAD52, the telomere length. Telomere elongation achieved by the activation of PAX7 and PAX9 is associated with a poor prognosis. We demonstrated that TGF-β superfamily-induced transcriptional activation pathways activated the RAD52-dependent ALT during malignant transformation of MPNSTs.
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Affiliation(s)
- Eunji Choi
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, The Graduate School, Yonsei University, Seoul, 03722, Republic of Korea
| | - Jungwoo Lee
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, The Graduate School, Yonsei University, Seoul, 03722, Republic of Korea
| | - HyoJu Kim
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, The Graduate School, Yonsei University, Seoul, 03722, Republic of Korea
| | - Young-Joon Kim
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, The Graduate School, Yonsei University, Seoul, 03722, Republic of Korea
| | - Seung Hyun Kim
- Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea.
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18
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Osia B, Merkell A, Lopezcolorado FW, Ping X, Stark JM. RAD52 and ERCC6L/PICH have a compensatory relationship for genome stability in mitosis. PLoS Genet 2024; 20:e1011479. [PMID: 39561207 PMCID: PMC11614213 DOI: 10.1371/journal.pgen.1011479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 12/03/2024] [Accepted: 10/31/2024] [Indexed: 11/21/2024] Open
Abstract
Mammalian RAD52 is a DNA repair factor with strand annealing and recombination mediator activities that appear important in both interphase and mitotic cells. Nonetheless, RAD52 is dispensable for cell viability. To query RAD52 synthetic lethal relationships, we performed genome-wide CRISPR knock-out screens and identified hundreds of candidate synthetic lethal interactions. We then performed secondary screening and identified genes for which depletion causes reduced viability and elevated genome instability (increased 53BP1 nuclear foci) in RAD52-deficient cells. One such factor was ERCC6L, which marks DNA bridges during anaphase, and hence is important for genome stability in mitosis. Thus, we investigated the functional interrelationship between RAD52 and ERCC6L. We found that RAD52 deficiency increases ERCC6L-coated anaphase ultrafine bridges, and that ERCC6L depletion causes elevated RAD52 foci in prometaphase and interphase cells. These effects were enhanced with replication stress (i.e. hydroxyurea) and topoisomerase IIα inhibition (ICRF-193), where post-treatment effect timings were consistent with defects in addressing stress in mitosis. Altogether, we suggest that RAD52 and ERCC6L co-compensate to protect genome stability in mitosis.
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Affiliation(s)
- Beth Osia
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, California, United States of America
| | - Arianna Merkell
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, California, United States of America
| | - Felicia Wednesday Lopezcolorado
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, California, United States of America
| | - Xiaoli Ping
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, California, United States of America
| | - Jeremy M. Stark
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, California, United States of America
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19
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Kim S, Park S, Kang N, Ra J, Myung K, Lee KY. Polyubiquitinated PCNA triggers SLX4-mediated break-induced replication in alternative lengthening of telomeres (ALT) cancer cells. Nucleic Acids Res 2024; 52:11785-11805. [PMID: 39291733 PMCID: PMC11514459 DOI: 10.1093/nar/gkae785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 08/23/2024] [Accepted: 08/29/2024] [Indexed: 09/19/2024] Open
Abstract
Replication stresses are the major source of break-induced replication (BIR). Here, we show that in alternative lengthening of telomeres (ALT) cells, replication stress-induced polyubiquitinated proliferating cell nuclear antigen (PCNA) (polyUb-PCNA) triggers BIR at telomeres and the common fragile site (CFS). Consistently, depleting RAD18, a PCNA ubiquitinating enzyme, reduces the occurrence of ALT-associated promyelocytic leukemia (PML) bodies (APBs) and mitotic DNA synthesis at telomeres and CFS, both of which are mediated by BIR. In contrast, inhibiting ubiquitin-specific protease 1 (USP1), an Ub-PCNA deubiquitinating enzyme, results in an increase in the above phenotypes in a RAD18- and UBE2N (the PCNA polyubiquitinating enzyme)-dependent manner. Furthermore, deficiency of ATAD5, which facilitates USP1 activity and unloads PCNAs, augments recombination-associated phenotypes. Mechanistically, telomeric polyUb-PCNA accumulates SLX4, a nuclease scaffold, at telomeres through its ubiquitin-binding domain and increases telomere damage. Consistently, APB increase induced by Ub-PCNA depends on SLX4 and structure-specific endonucleases. Taken together, our results identified the polyUb-PCNA-SLX4 axis as a trigger for directing BIR.
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Affiliation(s)
- Sangin Kim
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Korea
- Department of Biological Sciences, College of Information-Bio Convergence Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| | - Su Hyung Park
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Korea
- Department of Biomedical Engineering, College of Information-Bio Convergence Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| | - Nalae Kang
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Korea
| | - Jae Sun Ra
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Korea
| | - Kyungjae Myung
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Korea
- Department of Biomedical Engineering, College of Information-Bio Convergence Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| | - Kyoo-young Lee
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Korea
- Department of Biochemistry, College of Medicine, Hallym University, Chuncheon 24252, Gangwon-do, Republic of Korea
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20
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Wang B, Kou H, Wang Y, Zhang Q, Jiang D, Wang J, Zhao Z, Zhou Y, Zhang M, Sui L, Zhao M, Liu Y, Liu Y, Shi L, Wang F. LAP2α orchestrates alternative lengthening of telomeres suppression through telomeric heterochromatin regulation with HDAC1: unveiling a potential therapeutic target. Cell Death Dis 2024; 15:761. [PMID: 39426946 PMCID: PMC11490576 DOI: 10.1038/s41419-024-07116-4] [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: 02/01/2024] [Revised: 09/23/2024] [Accepted: 09/26/2024] [Indexed: 10/21/2024]
Abstract
In response to the challenge of telomere attrition during DNA replication, cancer cells predominantly employ telomerase or, in 10-15% of cases, the alternative lengthening of telomeres (ALT). The intricate details of ALT, however, remain elusive. In this study, we unveil that the knockdown of lamina-associated polypeptide 2 alpha (LAP2α) in ALT cells results in telomere dysfunction, triggering a notable increase in ALT-associated hallmarks, including high frequencies of PML bodies (APBs), C-rich extrachromosomal circles (C-circles), and telomere sister chromatid exchange (T-SCE). Furthermore, LAP2α emerges as a crucial player in break-induced telomere replication for telomerase-positive cells following telomeric double-strand breaks. Mechanistically, our investigation suggests that LAP2α may influence the regulation of the heterochromatic state of telomeres, thereby affecting telomeric accessibility. In line with our findings, LAP2α expression is markedly reduced in ALT-positive osteosarcoma. And the use of methotrexate (MTX) can restore the heterochromatin state altered by LAP2α depletion. This is evidenced by a significant inhibition of tumor proliferation in ALT-positive patient-derived xenograft (PDX) mouse models. These results indicate the important role of LAP2α in regulating ALT activity and offer insights into the interplay between lamina-associated proteins and telomeres in maintaining telomere length. Importantly, our findings may help identify a more appropriate target population for the osteosarcoma therapeutic drug, MTX.
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Grants
- 32170762 National Natural Science Foundation of China (National Science Foundation of China)
- This work was supported by the grant from the National Natural Science Foundation of China (No. 32170762, 3217050514, 31771520, 31471293, 91649102, 92149302, 81772243, 81771135, 81970958, 82303619), Tianjin Health Research Project (No. 19YFZCSY00600), Science and Technology Project of Tianjin Municipal Health Committee (No. TJWJ2022XK018, TJWJ2022QN030) and the Natural Science Foundation of Tianjin City (No. 19JCJQJC63500)
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Affiliation(s)
- Bing Wang
- The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Department of Genetics, School of Basic Medical Science, Institute of Prosthodontics School and Hospital of Stomatology, General Hospital, Tianjin Medical University, 300070, Tianjin, P. R. China
- Department of Hematology, Tianjin First Central Hospital, 300192, Tianjin, P. R. China
| | - Haomeng Kou
- The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Department of Genetics, School of Basic Medical Science, Institute of Prosthodontics School and Hospital of Stomatology, General Hospital, Tianjin Medical University, 300070, Tianjin, P. R. China
| | - Yuwen Wang
- The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Department of Genetics, School of Basic Medical Science, Institute of Prosthodontics School and Hospital of Stomatology, General Hospital, Tianjin Medical University, 300070, Tianjin, P. R. China
| | - Qi Zhang
- Department of Clinical Laboratory, First Affiliated Hospital of Xi'an Jiaotong University, 710061, Xi'an, Shaanxi, P. R. China
| | - Duo Jiang
- The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Department of Genetics, School of Basic Medical Science, Institute of Prosthodontics School and Hospital of Stomatology, General Hospital, Tianjin Medical University, 300070, Tianjin, P. R. China
| | - Juan Wang
- The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Department of Genetics, School of Basic Medical Science, Institute of Prosthodontics School and Hospital of Stomatology, General Hospital, Tianjin Medical University, 300070, Tianjin, P. R. China
| | - Ziqin Zhao
- Department of Pathology, Tianjin Hospital, 300221, Tianjin, P. R. China
| | - Yao Zhou
- Department of Bioinformatics, The Province and Ministry Co-Sponsored Collaborative Innovation Center for Medical Epigenetics, School of Basic Medical Sciences, Tianjin Medical University, 300070, Tianjin, P. R. China
| | - Miaomiao Zhang
- Department of Pathology, Jining No.1 People's Hospital, 272000, Jining, Shandong, P. R. China
| | - Lei Sui
- Department of Prosthodontics, School and Hospital of Stomatology, Tianjin Medical University, 300070, Tianjin, P. R. China
| | - Mingfeng Zhao
- Department of Hematology, Tianjin First Central Hospital, 300192, Tianjin, P. R. China
| | - Yancheng Liu
- Department of Bone and Soft Tissue Oncology, Tianjin Hospital, 300221, Tianjin, P. R. China.
| | - Yang Liu
- Department of Radiobiology, Institute of Radiation Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, 300192, Tianjin, P. R. China.
| | - Lei Shi
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, 300070, Tianjin, P. R. China.
| | - Feng Wang
- The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Department of Genetics, School of Basic Medical Science, Institute of Prosthodontics School and Hospital of Stomatology, General Hospital, Tianjin Medical University, 300070, Tianjin, P. R. China.
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21
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Shah SB, Li Y, Li S, Hu Q, Wu T, Shi Y, Nguyen T, Ive I, Shi L, Wang H, Wu X. 53BP1 deficiency leads to hyperrecombination using break-induced replication (BIR). Nat Commun 2024; 15:8648. [PMID: 39368985 PMCID: PMC11455893 DOI: 10.1038/s41467-024-52916-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Accepted: 09/19/2024] [Indexed: 10/07/2024] Open
Abstract
Break-induced replication (BIR) is mutagenic, and thus its use requires tight regulation, yet the underlying mechanisms remain elusive. Here we uncover an important role of 53BP1 in suppressing BIR after end resection at double strand breaks (DSBs), distinct from its end protection activity, providing insight into the mechanisms governing BIR regulation and DSB repair pathway selection. We demonstrate that loss of 53BP1 induces BIR-like hyperrecombination, in a manner dependent on Polα-primase-mediated end fill-in DNA synthesis on single-stranded DNA (ssDNA) overhangs at DSBs, leading to PCNA ubiquitination and PIF1 recruitment to activate BIR. On broken replication forks, where BIR is required for repairing single-ended DSBs (seDSBs), SMARCAD1 displaces 53BP1 to facilitate the localization of ubiquitinated PCNA and PIF1 to DSBs for BIR activation. Hyper BIR associated with 53BP1 deficiency manifests template switching and large deletions, underscoring another aspect of 53BP1 in suppressing genome instability. The synthetic lethal interaction between the 53BP1 and BIR pathways provides opportunities for targeted cancer treatment.
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Affiliation(s)
- Sameer Bikram Shah
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Youhang Li
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
- College of Life Science, Capital Normal University, Beijing, 100037, China
| | - Shibo Li
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
- College of Life Sciences, Tianjin Normal University, Tianjin, 300387, China
| | - Qing Hu
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Tong Wu
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Yanmeng Shi
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Tran Nguyen
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Isaac Ive
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Linda Shi
- The Institute of Engineering in Medicine, University of California, San Diego, California, 92093, USA
| | - Hailong Wang
- College of Life Science, Capital Normal University, Beijing, 100037, China
| | - Xiaohua Wu
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA.
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22
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Blaize JL, Garzon JLN, Howlett NG. FANCD2 genome binding is nonrandom and is enriched at large transcriptionally active neural genes prone to copy number variation. Funct Integr Genomics 2024; 24:180. [PMID: 39365306 PMCID: PMC11452531 DOI: 10.1007/s10142-024-01453-5] [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: 07/03/2024] [Revised: 09/01/2024] [Accepted: 09/10/2024] [Indexed: 10/05/2024]
Abstract
Fanconi anemia (FA) is a rare genetic disease characterized by congenital abnormalities and increased risk for bone marrow failure and cancer. Central nervous system defects, including acute and irreversible loss of neurological function and white matter lesions with calcifications, have become increasingly recognized among FA patients, and are collectively referred to as Fanconi Anemia Neurological Syndrome or FANS. The molecular etiology of FANS is poorly understood. In this study, we have used a functional integrative genomics approach to further define the function of the FANCD2 protein and FA pathway. Combined analysis of new and existing FANCD2 ChIP-seq datasets demonstrates that FANCD2 binds nonrandomly throughout the genome with binding enriched at transcription start sites and in broad regions spanning protein-coding gene bodies. FANCD2 demonstrates a strong preference for large neural genes involved in neuronal differentiation, synapse function, and cell adhesion, with many of these genes implicated in neurodevelopmental and neuropsychiatric disorders. Furthermore, FANCD2 binds to regions of the genome that replicate late, undergo mitotic DNA synthesis (MiDAS) under conditions of replication stress, and are hotspots for copy number variation. Our analysis describes an important targeted role for FANCD2 and the FA pathway in the maintenance of large neural gene stability.
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Affiliation(s)
- Justin L Blaize
- Department of Cell and Molecular Biology, University of Rhode Island, 379 Center for Biotechnology and Life Sciences, 120 Flagg Road, Kingston, RI, USA
| | - Jada Lauren N Garzon
- Department of Cell and Molecular Biology, University of Rhode Island, 379 Center for Biotechnology and Life Sciences, 120 Flagg Road, Kingston, RI, USA
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Niall G Howlett
- Department of Cell and Molecular Biology, University of Rhode Island, 379 Center for Biotechnology and Life Sciences, 120 Flagg Road, Kingston, RI, USA.
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23
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Lee RS, Twarowski JM, Malkova A. Stressed? Break-induced replication comes to the rescue! DNA Repair (Amst) 2024; 142:103759. [PMID: 39241677 DOI: 10.1016/j.dnarep.2024.103759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 08/22/2024] [Accepted: 08/26/2024] [Indexed: 09/09/2024]
Abstract
Break-induced replication (BIR) is a homologous recombination (HR) pathway that repairs one-ended DNA double-strand breaks (DSBs), which can result from replication fork collapse, telomere erosion, and other events. Eukaryotic BIR has been mainly investigated in yeast, where it is initiated by invasion of the broken DNA end into a homologous sequence, followed by extensive replication synthesis proceeding to the chromosome end. Multiple recent studies have described BIR in mammalian cells, the properties of which show many similarities to yeast BIR. While HR is considered as "error-free" mechanism, BIR is highly mutagenic and frequently leads to chromosomal rearrangements-genetic instabilities known to promote human disease. In addition, it is now recognized that BIR is highly stimulated by replication stress (RS), including RS constantly present in cancer cells, implicating BIR as a contributor to cancer genesis and progression. Here, we discuss the past and current findings related to the mechanism of BIR, the association of BIR with replication stress, and the destabilizing effects of BIR on the eukaryotic genome. Finally, we consider the potential for exploiting the BIR machinery to develop anti-cancer therapeutics.
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Affiliation(s)
- Rosemary S Lee
- Department of Biochemistry & Structural Biology, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | | | - Anna Malkova
- Department of Biochemistry & Structural Biology, University of Texas Health San Antonio, San Antonio, TX 78229, USA.
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24
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Honda M, Razzaghi M, Gaur P, Malacaria E, Marozzi G, Biagi LD, Aiello FA, Paintsil EA, Stanfield AJ, Deppe BJ, Gakhar L, Schnicker NJ, Ashley Spies M, Pichierri P, Spies M. A double-ring of human RAD52 remodels replication forks restricting fork reversal. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.14.566657. [PMID: 38014173 PMCID: PMC10680749 DOI: 10.1101/2023.11.14.566657] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Human RAD52 1,2 is a multifunctional DNA repair protein involved in several cellular events that support genome stability including protection of stalled DNA replication forks from excessive degradation 3-7 . In its gatekeeper role, RAD52 binds to and stabilizes stalled replication forks during replication stress protecting them from reversal by SMARCAL1 5 . The structural and molecular mechanism of the RAD52-mediated fork protection remains elusive. Here, using P1 nuclease sensitivity, biochemical and single-molecule analyses we show that RAD52 dynamically remodels replication forks through its strand exchange activity. The presence of the ssDNA binding protein RPA at the fork modulates the kinetics of the strand exchange without impeding the reaction outcome. Mass photometry and single-particle cryo-electron microscopy show that the replication fork promotes a unique nucleoprotein structure containing head-to-head arrangement of two undecameric RAD52 rings with an extended positively charged surface that accommodates all three arms of the replication fork. We propose that the formation and continuity of this surface is important for the strand exchange reaction and for competition with SMARCAL1. One Sentence Summary Using cryo-EM, biochemical and single-molecule approaches we show that the structure of stalled DNA replication fork promotes a unique two-ring organization of human RAD52 protein which remodels the fork via DNA strand exchange.
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25
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Shah SB, Li Y, Li S, Hu Q, Wu T, Shi Y, Nguyen T, Ive I, Shi L, Wang H, Wu X. 53BP1 deficiency leads to hyperrecombination using break-induced replication (BIR). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.11.612483. [PMID: 39314326 PMCID: PMC11419065 DOI: 10.1101/2024.09.11.612483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
Break-induced replication (BIR) is mutagenic, and thus its use requires tight regulation, yet the underlying mechanisms remain elusive. Here we uncover an important role of 53BP1 in suppressing BIR after end resection at double strand breaks (DSBs), distinct from its end protection activity, providing insight into the mechanisms governing BIR regulation and DSB repair pathway selection. We demonstrate that loss of 53BP1 induces BIR-like hyperrecombination, in a manner dependent on Polα-primase-mediated end fill-in DNA synthesis on single-stranded DNA (ssDNA) overhangs at DSBs, leading to PCNA ubiquitination and PIF1 recruitment to activate BIR. On broken replication forks, where BIR is required for repairing single-ended DSBs (seDSBs), SMARCAD1 displaces 53BP1 to facilitate the localization of ubiquitinated PCNA and PIF1 to DSBs for BIR activation. Hyper BIR associated with 53BP1 deficiency manifests template switching and large deletions, underscoring another aspect of 53BP1 in suppressing genome instability. The synthetic lethal interaction between the 53BP1 and BIR pathways provides opportunities for targeted cancer treatment.
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Affiliation(s)
- Sameer Bikram Shah
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Youhang Li
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- College of Life Science, Capital Normal University, Beijing 100037, China
| | - Shibo Li
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- College of Life Sciences, Tianjin Normal University, Tianjin, 300387, China
| | - Qing Hu
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Tong Wu
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Yanmeng Shi
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Tran Nguyen
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Isaac Ive
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Linda Shi
- The Institute of Engineering in Medicine, University of California, San Diego, California 92093, USA
| | - Hailong Wang
- College of Life Science, Capital Normal University, Beijing 100037, China
| | - Xiaohua Wu
- Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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26
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Paul Chowdhuri S, Das BB. TDP1 phosphorylation by CDK1 in mitosis promotes MUS81-dependent repair of trapped Top1-DNA covalent complexes. EMBO J 2024; 43:3710-3732. [PMID: 39014228 PMCID: PMC11377750 DOI: 10.1038/s44318-024-00169-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 06/26/2024] [Accepted: 06/28/2024] [Indexed: 07/18/2024] Open
Abstract
Topoisomerase 1 (Top1) controls DNA topology, relieves DNA supercoiling during replication and transcription, and is critical for mitotic progression to the G1 phase. Tyrosyl-DNA phosphodiesterase 1 (TDP1) mediates the removal of trapped Top1-DNA covalent complexes (Top1cc). Here, we identify CDK1-dependent phosphorylation of TDP1 at residue S61 during mitosis. A TDP1 variant defective for S61 phosphorylation (TDP1-S61A) is trapped on the mitotic chromosomes, triggering DNA damage and mitotic defects. Moreover, we show that Top1cc repair in mitosis occurs via a MUS81-dependent DNA repair mechanism. Replication stress induced by camptothecin or aphidicolin leads to TDP1-S61A enrichment at common fragile sites, which over-stimulates MUS81-dependent chromatid breaks, anaphase bridges, and micronuclei, ultimately culminating in the formation of 53BP1 nuclear bodies during G1 phase. Our findings provide new insights into the cell cycle-dependent regulation of TDP1 dynamics for the repair of trapped Top1-DNA covalent complexes during mitosis that prevents genomic instability following replication stress.
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Affiliation(s)
- Srijita Paul Chowdhuri
- Laboratory of Molecular Biology, School of Biological Sciences, Indian Association for the Cultivation of Science, 2A & B, Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal, 700032, India
| | - Benu Brata Das
- Laboratory of Molecular Biology, School of Biological Sciences, Indian Association for the Cultivation of Science, 2A & B, Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal, 700032, India.
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27
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Hanthi YW, Ramirez-Otero MA, Appleby R, De Antoni A, Joudeh L, Sannino V, Waked S, Ardizzoia A, Barra V, Fachinetti D, Pellegrini L, Costanzo V. RAD51 protects abasic sites to prevent replication fork breakage. Mol Cell 2024; 84:3026-3043.e11. [PMID: 39178838 DOI: 10.1016/j.molcel.2024.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 06/03/2024] [Accepted: 07/08/2024] [Indexed: 08/26/2024]
Abstract
Abasic sites are DNA lesions repaired by base excision repair. Cleavage of unrepaired abasic sites in single-stranded DNA (ssDNA) can lead to chromosomal breakage during DNA replication. How rupture of abasic DNA is prevented remains poorly understood. Here, using cryoelectron microscopy (cryo-EM), Xenopus laevis egg extracts, and human cells, we show that RAD51 nucleofilaments specifically recognize and protect abasic sites, which increase RAD51 association rate to DNA. In the absence of BRCA2 or RAD51, abasic sites accumulate as a result of DNA base methylation, oxidation, and deamination, inducing abasic ssDNA gaps that make replicating DNA fibers sensitive to APE1. RAD51 assembled on abasic DNA prevents abasic site cleavage by the MRE11-RAD50 complex, suppressing replication fork breakage triggered by an excess of abasic sites or POLθ polymerase inhibition. Our study highlights the critical role of BRCA2 and RAD51 in safeguarding against unrepaired abasic sites in DNA templates stemming from base alterations, ensuring genomic stability.
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Affiliation(s)
| | | | - Robert Appleby
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | - Anna De Antoni
- IFOM, The AIRC Institute of Molecular Oncology, Milan, Italy
| | - Luay Joudeh
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | | | - Salli Waked
- IFOM, The AIRC Institute of Molecular Oncology, Milan, Italy
| | | | - Viviana Barra
- Institute Curie, PSL Research University, CNRS, UMR 144, 26 Rue d'Ulm, 75005 Paris, France
| | - Daniele Fachinetti
- Institute Curie, PSL Research University, CNRS, UMR 144, 26 Rue d'Ulm, 75005 Paris, France
| | - Luca Pellegrini
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK.
| | - Vincenzo Costanzo
- IFOM, The AIRC Institute of Molecular Oncology, Milan, Italy; Department of Oncology and Hematology-Oncology, University of Milan, Milan, Italy.
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28
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Zhao Y, Hou K, Liu Y, Na Y, Li C, Luo H, Wang H. Helicase HELQ: Molecular Characters Fit for DSB Repair Function. Int J Mol Sci 2024; 25:8634. [PMID: 39201320 PMCID: PMC11355030 DOI: 10.3390/ijms25168634] [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: 06/23/2024] [Revised: 08/02/2024] [Accepted: 08/06/2024] [Indexed: 09/02/2024] Open
Abstract
The protein sequence and spatial structure of DNA helicase HELQ are highly conserved, spanning from archaea to humans. Aside from its helicase activity, which is based on DNA binding and translocation, it has also been recently reconfirmed that human HELQ possesses DNA-strand-annealing activity, similar to that of the archaeal HELQ homolog StoHjm. These biochemical functions play an important role in regulating various double-strand break (DSB) repair pathways, as well as multiple steps in different DSB repair processes. HELQ primarily facilitates repair in end-resection-dependent DSB repair pathways, such as homologous recombination (HR), single-strand annealing (SSA), microhomology-mediated end joining (MMEJ), as well as the sub-pathways' synthesis-dependent strand annealing (SDSA) and break-induced replication (BIR) within HR. The biochemical functions of HELQ are significant in end resection and its downstream pathways, such as strand invasion, DNA synthesis, and gene conversion. Different biochemical activities are required to support DSB repair at various stages. This review focuses on the functional studies of the biochemical roles of HELQ during different stages of diverse DSB repair pathways.
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Affiliation(s)
| | | | | | | | | | | | - Hailong Wang
- Beijing Key Laboratory of DNA Damage Response, College of Life Sciences, Capital Normal University, Beijing 100048, China
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29
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Kojak N, Kuno J, Fittipaldi KE, Khan A, Wenger D, Glasser M, Donnianni RA, Tang Y, Zhang J, Huling K, Ally R, Mujica AO, Turner T, Magardino G, Huang PY, Kerk SY, Droguett G, Prissette M, Rojas J, Gomez T, Gagliardi A, Hunt C, Rabinowitz JS, Gong G, Poueymirou W, Chiao E, Zambrowicz B, Siao CJ, Kajimura D. Somatic and intergenerational G4C2 hexanucleotide repeat instability in a human C9orf72 knock-in mouse model. Nucleic Acids Res 2024; 52:5732-5755. [PMID: 38597682 PMCID: PMC11162798 DOI: 10.1093/nar/gkae250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 03/19/2024] [Accepted: 03/28/2024] [Indexed: 04/11/2024] Open
Abstract
Expansion of a G4C2 repeat in the C9orf72 gene is associated with familial Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD). To investigate the underlying mechanisms of repeat instability, which occurs both somatically and intergenerationally, we created a novel mouse model of familial ALS/FTD that harbors 96 copies of G4C2 repeats at a humanized C9orf72 locus. In mouse embryonic stem cells, we observed two modes of repeat expansion. First, we noted minor increases in repeat length per expansion event, which was dependent on a mismatch repair pathway protein Msh2. Second, we found major increases in repeat length per event when a DNA double- or single-strand break (DSB/SSB) was artificially introduced proximal to the repeats, and which was dependent on the homology-directed repair (HDR) pathway. In mice, the first mode primarily drove somatic repeat expansion. Major changes in repeat length, including expansion, were observed when SSB was introduced in one-cell embryos, or intergenerationally without DSB/SSB introduction if G4C2 repeats exceeded 400 copies, although spontaneous HDR-mediated expansion has yet to be identified. These findings provide a novel strategy to model repeat expansion in a non-human genome and offer insights into the mechanism behind C9orf72 G4C2 repeat instability.
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Affiliation(s)
- Nada Kojak
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Junko Kuno
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | | | - David Wenger
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | | | - Yajun Tang
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Jade Zhang
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Katie Huling
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Roxanne Ally
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | | | | | - Pei Yi Huang
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Sze Yen Kerk
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | | | - Jose Rojas
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | | | | | | | - Guochun Gong
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | - Eric Chiao
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
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30
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Lee JJ, Kim H, Park H, Lee U, Kim C, Lee M, Shin Y, Jung JJ, Lee HB, Han W, Lee H. Disruption of G-quadruplex dynamicity by BRCA2 abrogation instigates phase separation and break-induced replication at telomeres. Nucleic Acids Res 2024; 52:5756-5773. [PMID: 38587189 PMCID: PMC11162766 DOI: 10.1093/nar/gkae251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 03/08/2024] [Accepted: 04/03/2024] [Indexed: 04/09/2024] Open
Abstract
Dynamic interaction between BRCA2 and telomeric G-quadruplexes (G4) is crucial for maintaining telomere replication homeostasis. Cells lacking BRCA2 display telomeric damage with a subset of these cells bypassing senescence to initiate break-induced replication (BIR) for telomere synthesis. Here we show that the abnormal stabilization of telomeric G4 following BRCA2 depletion leads to telomeric repeat-containing RNA (TERRA)-R-loop accumulation, triggering liquid-liquid phase separation (LLPS) and the assembly of Alternative Lengthening of Telomeres (ALT)-associated promyelocytic leukemia (PML) bodies (APBs). Disruption of R-loops abolishes LLPS and impairs telomere synthesis. Artificial engineering of telomeric LLPS restores telomere synthesis, underscoring the critical role of LLPS in ALT. TERRA-R-loops also recruit Polycomb Repressive Complex 2 (PRC2), leading to tri-methylation of Lys27 on histone H3 (H3K27me3) at telomeres. Half of paraffin-embedded tissue sections from human breast cancers exhibit APBs and telomere length heterogeneity, suggesting that BRCA2 mutations can predispose individuals to ALT-type tumorigenesis. Overall, BRCA2 abrogation disrupts the dynamicity of telomeric G4, producing TERRA-R-loops, finally leading to the assembly of telomeric liquid condensates crucial for ALT. We propose that modulating the dynamicity of telomeric G4 and targeting TERRA-R-loops in telomeric LLPS maintenance may represent effective therapeutic strategies for treating ALT-like cancers with APBs, including those with BRCA2 disruptions.
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Affiliation(s)
- Jennifer J Lee
- Department of Biological Sciences & Institute of Molecular Biology and Genetics (IMBG), Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
| | - Hyungmin Kim
- Department of Biological Sciences & Institute of Molecular Biology and Genetics (IMBG), Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
| | - Haemin Park
- Department of Biological Sciences & Institute of Molecular Biology and Genetics (IMBG), Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
| | - UkJin Lee
- Department of Biological Sciences & Institute of Molecular Biology and Genetics (IMBG), Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
| | - Chaelim Kim
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Korea
| | - Min Lee
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Korea
| | - Yongdae Shin
- Department of Mechanical Engineering, Seoul National University, Seoul 08826, Korea
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Korea
| | - Ji-Jung Jung
- Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Han-Byoel Lee
- Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea
- Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Korea
- Cancer Research Institute, Seoul National University, Seoul 03080, Korea
| | - Wonshik Han
- Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea
- Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Korea
- Cancer Research Institute, Seoul National University, Seoul 03080, Korea
| | - Hyunsook Lee
- Department of Biological Sciences & Institute of Molecular Biology and Genetics (IMBG), Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
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31
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Liang CC, Greenhough LA, Masino L, Maslen S, Bajrami I, Tuppi M, Skehel M, Taylor IA, West SC. Mechanism of single-stranded DNA annealing by RAD52-RPA complex. Nature 2024; 629:697-703. [PMID: 38658755 PMCID: PMC11096129 DOI: 10.1038/s41586-024-07347-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 03/22/2024] [Indexed: 04/26/2024]
Abstract
RAD52 is important for the repair of DNA double-stranded breaks1,2, mitotic DNA synthesis3-5 and alternative telomere length maintenance6,7. Central to these functions, RAD52 promotes the annealing of complementary single-stranded DNA (ssDNA)8,9 and provides an alternative to BRCA2/RAD51-dependent homologous recombination repair10. Inactivation of RAD52 in homologous-recombination-deficient BRCA1- or BRCA2-defective cells is synthetically lethal11,12, and aberrant expression of RAD52 is associated with poor cancer prognosis13,14. As a consequence, RAD52 is an attractive therapeutic target against homologous-recombination-deficient breast, ovarian and prostate cancers15-17. Here we describe the structure of RAD52 and define the mechanism of annealing. As reported previously18-20, RAD52 forms undecameric (11-subunit) ring structures, but these rings do not represent the active form of the enzyme. Instead, cryo-electron microscopy and biochemical analyses revealed that ssDNA annealing is driven by RAD52 open rings in association with replication protein-A (RPA). Atomic models of the RAD52-ssDNA complex show that ssDNA sits in a positively charged channel around the ring. Annealing is driven by the RAD52 N-terminal domains, whereas the C-terminal regions modulate the open-ring conformation and RPA interaction. RPA associates with RAD52 at the site of ring opening with critical interactions occurring between the RPA-interacting domain of RAD52 and the winged helix domain of RPA2. Our studies provide structural snapshots throughout the annealing process and define the molecular mechanism of ssDNA annealing by the RAD52-RPA complex.
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Affiliation(s)
| | | | | | | | | | - Marcel Tuppi
- The Francis Crick Institute, London, UK
- Abcam, Cambridge Biomedical Campus, Cambridge, UK
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32
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Audrey A, Kok YP, Yu S, de Haan L, van de Kooij B, van den Tempel N, Chen M, de Boer HR, van der Vegt B, van Vugt MATM. RAD52-dependent mitotic DNA synthesis is required for genome stability in Cyclin E1-overexpressing cells. Cell Rep 2024; 43:114116. [PMID: 38625790 DOI: 10.1016/j.celrep.2024.114116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/28/2024] [Accepted: 03/29/2024] [Indexed: 04/18/2024] Open
Abstract
Overexpression of Cyclin E1 perturbs DNA replication, resulting in DNA lesions and genomic instability. Consequently, Cyclin E1-overexpressing cancer cells increasingly rely on DNA repair, including RAD52-mediated break-induced replication during interphase. We show that not all DNA lesions induced by Cyclin E1 overexpression are resolved during interphase. While DNA lesions upon Cyclin E1 overexpression are induced in S phase, a significant fraction of these lesions is transmitted into mitosis. Cyclin E1 overexpression triggers mitotic DNA synthesis (MiDAS) in a RAD52-dependent fashion. Chemical or genetic inactivation of MiDAS enhances mitotic aberrations and persistent DNA damage. Mitosis-specific degradation of RAD52 prevents Cyclin E1-induced MiDAS and reduces the viability of Cyclin E1-overexpressing cells, underscoring the relevance of RAD52 during mitosis to maintain genomic integrity. Finally, analysis of breast cancer samples reveals a positive correlation between Cyclin E1 amplification and RAD52 expression. These findings demonstrate the importance of suppressing mitotic defects in Cyclin E1-overexpressing cells through RAD52.
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Affiliation(s)
- Anastasia Audrey
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, the Netherlands
| | - Yannick P Kok
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, the Netherlands
| | - Shibo Yu
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ Groningen, the Netherlands
| | - Lauren de Haan
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, the Netherlands
| | - Bert van de Kooij
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, the Netherlands
| | - Nathalie van den Tempel
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, the Netherlands
| | - Mengting Chen
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, the Netherlands
| | - H Rudolf de Boer
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, the Netherlands
| | - Bert van der Vegt
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ Groningen, the Netherlands
| | - Marcel A T M van Vugt
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, the Netherlands.
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Jones RM, Reynolds-Winczura A, Gambus A. A Decade of Discovery-Eukaryotic Replisome Disassembly at Replication Termination. BIOLOGY 2024; 13:233. [PMID: 38666845 PMCID: PMC11048390 DOI: 10.3390/biology13040233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/23/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024]
Abstract
The eukaryotic replicative helicase (CMG complex) is assembled during DNA replication initiation in a highly regulated manner, which is described in depth by other manuscripts in this Issue. During DNA replication, the replicative helicase moves through the chromatin, unwinding DNA and facilitating nascent DNA synthesis by polymerases. Once the duplication of a replicon is complete, the CMG helicase and the remaining components of the replisome need to be removed from the chromatin. Research carried out over the last ten years has produced a breakthrough in our understanding, revealing that replication termination, and more specifically replisome disassembly, is indeed a highly regulated process. This review brings together our current understanding of these processes and highlights elements of the mechanism that are conserved or have undergone divergence throughout evolution. Finally, we discuss events beyond the classic termination of DNA replication in S-phase and go over the known mechanisms of replicative helicase removal from chromatin in these particular situations.
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Affiliation(s)
- Rebecca M. Jones
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham B15 2TT, UK; (R.M.J.); (A.R.-W.)
- School of Biosciences, Aston University, Birmingham B4 7ET, UK
| | - Alicja Reynolds-Winczura
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham B15 2TT, UK; (R.M.J.); (A.R.-W.)
| | - Agnieszka Gambus
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham B15 2TT, UK; (R.M.J.); (A.R.-W.)
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Showman S, Talbert PB, Xu Y, Adeyemi RO, Henikoff S. Expansion of human centromeric arrays in cells undergoing break-induced replication. Cell Rep 2024; 43:113851. [PMID: 38427559 PMCID: PMC11034957 DOI: 10.1016/j.celrep.2024.113851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 01/10/2024] [Accepted: 02/07/2024] [Indexed: 03/03/2024] Open
Abstract
Human centromeres are located within α-satellite arrays and evolve rapidly, which can lead to individual variation in array length. Proposed mechanisms for such alterations in length are unequal crossover between sister chromatids, gene conversion, and break-induced replication. However, the underlying molecular mechanisms responsible for the massive, complex, and homogeneous organization of centromeric arrays have not been experimentally validated. Here, we use droplet digital PCR assays to demonstrate that centromeric arrays can expand and contract within ∼20 somatic cell divisions of an alternative lengthening of telomere (ALT)-positive cell line. We find that the frequency of array variation among single-cell-derived subclones ranges from a minimum of ∼7% to a maximum of ∼100%. Further clonal evolution revealed that centromere expansion is favored over contraction. We find that the homologous recombination protein RAD52 and the helicase PIF1 are required for extensive array change, suggesting that centromere sequence evolution can occur via break-induced replication.
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Affiliation(s)
- Soyeon Showman
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Paul B Talbert
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Yiling Xu
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Richard O Adeyemi
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Steven Henikoff
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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Muhammad AA, Basto C, Peterlini T, Guirouilh-Barbat J, Thomas M, Veaute X, Busso D, Lopez B, Mazon G, Le Cam E, Masson JY, Dupaigne P. Human RAD52 stimulates the RAD51-mediated homology search. Life Sci Alliance 2024; 7:e202201751. [PMID: 38081641 PMCID: PMC10713436 DOI: 10.26508/lsa.202201751] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/01/2023] [Accepted: 12/01/2023] [Indexed: 12/18/2023] Open
Abstract
Homologous recombination (HR) is a DNA repair mechanism of double-strand breaks and blocked replication forks, involving a process of homology search leading to the formation of synaptic intermediates that are regulated to ensure genome integrity. RAD51 recombinase plays a central role in this mechanism, supported by its RAD52 and BRCA2 partners. If the mediator function of BRCA2 to load RAD51 on RPA-ssDNA is well established, the role of RAD52 in HR is still far from understood. We used transmission electron microscopy combined with biochemistry to characterize the sequential participation of RPA, RAD52, and BRCA2 in the assembly of the RAD51 filament and its activity. Although our results confirm that RAD52 lacks a mediator activity, RAD52 can tightly bind to RPA-coated ssDNA, inhibit the mediator activity of BRCA2, and form shorter RAD51-RAD52 mixed filaments that are more efficient in the formation of synaptic complexes and D-loops, resulting in more frequent multi-invasions as well. We confirm the in situ interaction between RAD51 and RAD52 after double-strand break induction in vivo. This study provides new molecular insights into the formation and regulation of presynaptic and synaptic intermediates by BRCA2 and RAD52 during human HR.
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Affiliation(s)
- Ali Akbar Muhammad
- Genome Integrity and Cancers UMR 9019 CNRS, Université Paris- Saclay, Gustave Roussy, Villejuif Cedex, France
| | - Clara Basto
- Genome Integrity and Cancers UMR 9019 CNRS, Université Paris- Saclay, Gustave Roussy, Villejuif Cedex, France
| | - Thibaut Peterlini
- Genome Stability Laboratory, CHU de Quebec Research Center, HDQ Pavilion, Oncology Axis, Quebec City, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Quebec City, Canada
| | - Josée Guirouilh-Barbat
- INSERM U1016, UMR 8104 CNRS, Institut Cochin, Equipe Labellisée Ligue Contre le Cancer, Université de Paris, Paris, France
| | - Melissa Thomas
- Genome Stability Laboratory, CHU de Quebec Research Center, HDQ Pavilion, Oncology Axis, Quebec City, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Quebec City, Canada
| | - Xavier Veaute
- CIGEx Platform, INSERM, IRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, Université de Paris and Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Didier Busso
- CIGEx Platform, INSERM, IRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, Université de Paris and Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Bernard Lopez
- INSERM U1016, UMR 8104 CNRS, Institut Cochin, Equipe Labellisée Ligue Contre le Cancer, Université de Paris, Paris, France
| | - Gerard Mazon
- Genome Integrity and Cancers UMR 9019 CNRS, Université Paris- Saclay, Gustave Roussy, Villejuif Cedex, France
| | - Eric Le Cam
- Genome Integrity and Cancers UMR 9019 CNRS, Université Paris- Saclay, Gustave Roussy, Villejuif Cedex, France
| | - Jean-Yves Masson
- Genome Stability Laboratory, CHU de Quebec Research Center, HDQ Pavilion, Oncology Axis, Quebec City, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Quebec City, Canada
| | - Pauline Dupaigne
- Genome Integrity and Cancers UMR 9019 CNRS, Université Paris- Saclay, Gustave Roussy, Villejuif Cedex, France
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Corazzi L, Ionasz V, Andrejev S, Wang LC, Vouzas A, Giaisi M, Di Muzio G, Ding B, Marx AJM, Henkenjohann J, Allers MM, Gilbert DM, Wei PC. Linear Interaction Between Replication and Transcription Shapes DNA Break Dynamics at Recurrent DNA Break Clusters. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.22.554340. [PMID: 37662334 PMCID: PMC10473677 DOI: 10.1101/2023.08.22.554340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Recurrent DNA break clusters (RDCs) are replication-transcription collision hotspots; many are unique to neural progenitor cells. Through high-resolution replication sequencing and a capture-ligation assay in mouse neural progenitor cells experiencing replication stress, we unraveled the replication features dictating RDC location and orientation. Most RDCs occur at the replication forks traversing timing transition regions (TTRs), where sparse replication origins connect unidirectional forks. Leftward-moving forks generate telomere-connected DNA double-strand breaks (DSBs), while rightward-moving forks lead to centromere-connected DSBs. Strand-specific mapping for DNA-bound RNA revealed co-transcriptional dual-strand DNA:RNA hybrids present at a higher density in RDC than in other actively transcribed long genes. In addition, mapping RNA polymerase activity revealed that head-to-head interactions between replication and transcription machinery resulted in 60% DSB contribution to the head-on compared to 40% for co-directional. Our findings revealed TTR as a novel fragile class and highlighted how the linear interaction between transcription and replication impacts genome stability.
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37
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Li Y, Zhang Y, Shah SB, Chang CY, Wang H, Wu X. MutSβ protects common fragile sites by facilitating homology-directed repair at DNA double-strand breaks with secondary structures. Nucleic Acids Res 2024; 52:1120-1135. [PMID: 38038265 PMCID: PMC10853791 DOI: 10.1093/nar/gkad1112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/14/2023] [Accepted: 11/07/2023] [Indexed: 12/02/2023] Open
Abstract
Common fragile sites (CFSs) are regions prone to chromosomal rearrangements, thereby contributing to tumorigenesis. Under replication stress (RS), CFSs often harbor under-replicated DNA regions at the onset of mitosis, triggering homology-directed repair known as mitotic DNA synthesis (MiDAS) to complete DNA replication. In this study, we identified an important role of DNA mismatch repair protein MutSβ (MSH2/MSH3) in facilitating MiDAS and maintaining CFS stability. Specifically, we demonstrated that MutSβ is required for the increased mitotic recombination induced by RS or FANCM loss at CFS-derived AT-rich and structure-prone sequences (CFS-ATs). We also found that MSH3 exhibits synthetic lethality with FANCM. Mechanistically, MutSβ is required for homologous recombination (HR) especially when DNA double-strand break (DSB) ends contain secondary structures. We also showed that upon RS, MutSβ is recruited to Flex1, a specific CFS-AT, in a PCNA-dependent but MUS81-independent manner. Furthermore, MutSβ interacts with RAD52 and promotes RAD52 recruitment to Flex1 following MUS81-dependent fork cleavage. RAD52, in turn, recruits XPF/ERCC1 to remove DNA secondary structures at DSB ends, enabling HR/break-induced replication (BIR) at CFS-ATs. We propose that the specific requirement of MutSβ in processing DNA secondary structures at CFS-ATs underlies its crucial role in promoting MiDAS and maintaining CFS integrity.
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Affiliation(s)
- Youhang Li
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Yunkun Zhang
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Sameer Bikram Shah
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Chia-Yu Chang
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Hailong Wang
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Xiaohua Wu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
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38
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Collin V, Biquand É, Tremblay V, Lavoie ÉG, Blondeau A, Gravel A, Galloy M, Lashgari A, Dessapt J, Côté J, Flamand L, Fradet-Turcotte A. The immediate-early protein 1 of human herpesvirus 6B interacts with NBS1 and inhibits ATM signaling. EMBO Rep 2024; 25:725-744. [PMID: 38177923 PMCID: PMC10897193 DOI: 10.1038/s44319-023-00035-z] [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: 03/07/2023] [Revised: 12/03/2023] [Accepted: 12/06/2023] [Indexed: 01/06/2024] Open
Abstract
Viral infection often trigger an ATM serine/threonine kinase (ATM)-dependent DNA damage response in host cells that suppresses viral replication. Viruses evolved different strategies to counteract this antiviral surveillance system. Here, we report that human herpesvirus 6B (HHV-6B) infection causes genomic instability by suppressing ATM signaling in host cells. Expression of immediate-early protein 1 (IE1) phenocopies this phenotype and blocks homology-directed double-strand break repair. Mechanistically, IE1 interacts with NBS1, and inhibits ATM signaling through two distinct domains. HHV-6B seems to efficiently inhibit ATM signaling as further depletion of either NBS1 or ATM do not significantly boost viral replication in infected cells. Interestingly, viral integration of HHV-6B into the host's telomeres is not strictly dependent on NBS1, challenging current models where integration occurs through homology-directed repair. Given that spontaneous IE1 expression has been detected in cells of subjects with inherited chromosomally-integrated form of HHV-6B (iciHHV-6B), a condition associated with several health conditions, our results raise the possibility of a link between genomic instability and the development of iciHHV-6-associated diseases.
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Affiliation(s)
- Vanessa Collin
- Division of Infectious Disease and Immunity, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1V 4G2, Canada
- Department of Microbiology, Infectious Disease and Immunology, Faculty of Medicine, Université Laval, Quebec City, QC, G1V 0A6, Canada
| | - Élise Biquand
- Oncology Division, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1R 2J6, Canada
- Department of Molecular biology, Medical Biochemistry and Pathology, Faculty of Medicine, Université Laval, Québec City, QC, G1V 0A6, Canada
- Université Laval Cancer Research Center, Université Laval, Quebec City, QC, G1R 3S3, Canada
- INSERM, Centre d'Étude des Pathologies Respiratoires (CEPR), UMR 1100, Université de Tours, Tours, France
| | - Vincent Tremblay
- Oncology Division, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1R 2J6, Canada
- Department of Molecular biology, Medical Biochemistry and Pathology, Faculty of Medicine, Université Laval, Québec City, QC, G1V 0A6, Canada
- Université Laval Cancer Research Center, Université Laval, Quebec City, QC, G1R 3S3, Canada
| | - Élise G Lavoie
- Oncology Division, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1R 2J6, Canada
- Université Laval Cancer Research Center, Université Laval, Quebec City, QC, G1R 3S3, Canada
| | - Andréanne Blondeau
- Oncology Division, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1R 2J6, Canada
- Université Laval Cancer Research Center, Université Laval, Quebec City, QC, G1R 3S3, Canada
| | - Annie Gravel
- Division of Infectious Disease and Immunity, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1V 4G2, Canada
- Department of Microbiology, Infectious Disease and Immunology, Faculty of Medicine, Université Laval, Quebec City, QC, G1V 0A6, Canada
| | - Maxime Galloy
- Oncology Division, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1R 2J6, Canada
- Department of Molecular biology, Medical Biochemistry and Pathology, Faculty of Medicine, Université Laval, Québec City, QC, G1V 0A6, Canada
- Université Laval Cancer Research Center, Université Laval, Quebec City, QC, G1R 3S3, Canada
| | - Anahita Lashgari
- Oncology Division, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1R 2J6, Canada
- Department of Molecular biology, Medical Biochemistry and Pathology, Faculty of Medicine, Université Laval, Québec City, QC, G1V 0A6, Canada
- Université Laval Cancer Research Center, Université Laval, Quebec City, QC, G1R 3S3, Canada
| | - Julien Dessapt
- Oncology Division, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1R 2J6, Canada
- Department of Molecular biology, Medical Biochemistry and Pathology, Faculty of Medicine, Université Laval, Québec City, QC, G1V 0A6, Canada
- Université Laval Cancer Research Center, Université Laval, Quebec City, QC, G1R 3S3, Canada
| | - Jacques Côté
- Oncology Division, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1R 2J6, Canada
- Department of Molecular biology, Medical Biochemistry and Pathology, Faculty of Medicine, Université Laval, Québec City, QC, G1V 0A6, Canada
- Université Laval Cancer Research Center, Université Laval, Quebec City, QC, G1R 3S3, Canada
| | - Louis Flamand
- Division of Infectious Disease and Immunity, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1V 4G2, Canada.
- Department of Microbiology, Infectious Disease and Immunology, Faculty of Medicine, Université Laval, Quebec City, QC, G1V 0A6, Canada.
| | - Amélie Fradet-Turcotte
- Oncology Division, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval Research Center, Quebec City, QC, G1R 2J6, Canada.
- Department of Molecular biology, Medical Biochemistry and Pathology, Faculty of Medicine, Université Laval, Québec City, QC, G1V 0A6, Canada.
- Université Laval Cancer Research Center, Université Laval, Quebec City, QC, G1R 3S3, Canada.
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Fenstermaker TK, Petruk S, Mazo A. An emerging paradigm in epigenetic marking: coordination of transcription and replication. Transcription 2024; 15:22-37. [PMID: 38378467 PMCID: PMC11093037 DOI: 10.1080/21541264.2024.2316965] [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: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/22/2024] Open
Abstract
DNA replication and RNA transcription both utilize DNA as a template and therefore need to coordinate their activities. The predominant theory in the field is that in order for the replication fork to proceed, transcription machinery has to be evicted from DNA until replication is complete. If that does not occur, these machineries collide, and these collisions elicit various repair mechanisms which require displacement of one of the enzymes, often RNA polymerase, in order for replication to proceed. This model is also at the heart of the epigenetic bookmarking theory, which implies that displacement of RNA polymerase during replication requires gradual re-building of chromatin structure, which guides recruitment of transcriptional proteins and resumption of transcription. We discuss these theories but also bring to light newer data that suggest that these two processes may not be as detrimental to one another as previously thought. This includes findings suggesting that these processes can occur without fork collapse and that RNA polymerase may only be transiently displaced during DNA replication. We discuss potential mechanisms by which RNA polymerase may be retained at the replication fork and quickly rebind to DNA post-replication. These discoveries are important, not only as new evidence as to how these two processes are able to occur harmoniously but also because they have implications on how transcriptional programs are maintained through DNA replication. To this end, we also discuss the coordination of replication and transcription in light of revising the current epigenetic bookmarking theory of how the active gene status can be transmitted through S phase.
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Affiliation(s)
- Tyler K. Fenstermaker
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Svetlana Petruk
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Alexander Mazo
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
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40
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Hourvitz N, Awad A, Tzfati Y. The many faces of the helicase RTEL1 at telomeres and beyond. Trends Cell Biol 2024; 34:109-121. [PMID: 37532653 DOI: 10.1016/j.tcb.2023.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/01/2023] [Accepted: 07/05/2023] [Indexed: 08/04/2023]
Abstract
Regulator of telomere elongation 1 (RTEL1) is known as a DNA helicase that is important for telomeres and genome integrity. However, the diverse phenotypes of RTEL1 dysfunction, the wide spectrum of symptoms caused by germline RTEL1 mutations, and the association of RTEL1 mutations with cancers suggest that RTEL1 is a complex machine that interacts with DNA, RNA, and proteins, and functions in diverse cellular pathways. We summarize the proposed functions of RTEL1 and discuss their implications for telomere maintenance. Studying RTEL1 is crucial for understanding the complex interplay between telomere maintenance and other nuclear pathways, and how compromising these pathways causes telomere biology diseases, various aging-associated pathologies, and cancer.
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Affiliation(s)
- Noa Hourvitz
- Department of Genetics, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Safra Campus, Jerusalem 91904, Israel
| | - Aya Awad
- Department of Genetics, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Safra Campus, Jerusalem 91904, Israel
| | - Yehuda Tzfati
- Department of Genetics, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Safra Campus, Jerusalem 91904, Israel.
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41
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Bournaka S, Badra-Fajardo N, Arbi M, Taraviras S, Lygerou Z. The cell cycle revisited: DNA replication past S phase preserves genome integrity. Semin Cancer Biol 2024; 99:45-55. [PMID: 38346544 DOI: 10.1016/j.semcancer.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/23/2024] [Accepted: 02/05/2024] [Indexed: 02/20/2024]
Abstract
Accurate and complete DNA duplication is critical for maintaining genome integrity. Multiple mechanisms regulate when and where DNA replication takes place, to ensure that the entire genome is duplicated once and only once per cell cycle. Although the bulk of the genome is copied during the S phase of the cell cycle, increasing evidence suggests that parts of the genome are replicated in G2 or mitosis, in a last attempt to secure that daughter cells inherit an accurate copy of parental DNA. Remaining unreplicated gaps may be passed down to progeny and replicated in the next G1 or S phase. These findings challenge the long-established view that genome duplication occurs strictly during the S phase, bridging DNA replication to DNA repair and providing novel therapeutic strategies for cancer treatment.
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Affiliation(s)
- Spyridoula Bournaka
- Department of General Biology, Medical School, University of Patras, Patras 26504, Greece
| | - Nibal Badra-Fajardo
- Department of General Biology, Medical School, University of Patras, Patras 26504, Greece
| | - Marina Arbi
- Department of General Biology, Medical School, University of Patras, Patras 26504, Greece
| | - Stavros Taraviras
- Department of Physiology, Medical School, University of Patras, Patras 26504, Greece
| | - Zoi Lygerou
- Department of General Biology, Medical School, University of Patras, Patras 26504, Greece.
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42
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Wang J, Chen Y, Li S, Liu W, Zhou XA, Luo Y, Xu Z, Xiong Y, Cheng K, Ruan M, Yu W, Li X, Wang W, Wang J. PP2A inhibition causes synthetic lethality in BRCA2-mutated prostate cancer models via spindle assembly checkpoint reactivation. J Clin Invest 2024; 134:e172137. [PMID: 37934606 PMCID: PMC10760972 DOI: 10.1172/jci172137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 10/31/2023] [Indexed: 11/09/2023] Open
Abstract
Mutations in the BRCA2 tumor suppressor gene have been associated with an increased risk of developing prostate cancer. One of the paradoxes concerning BRCA2 is the fact that its inactivation affects genetic stability and is deleterious for cellular and organismal survival, while BRCA2-mutated cancer cells adapt to this detriment and malignantly proliferate. Therapeutic strategies for tumors arising from BRCA2 mutations may be discovered by understanding these adaptive mechanisms. In this study, we conducted forward genetic synthetic viability screenings in Caenorhabditis elegans brc-2 (Cebrc-2) mutants and found that Ceubxn-2 inactivation rescued the viability of Cebrc-2 mutants. Moreover, loss of NSFL1C, the mammalian ortholog of CeUBXN-2, suppressed the spindle assembly checkpoint (SAC) activation and promoted the survival of BRCA2-deficient cells. Mechanistically, NSFL1C recruited USP9X to inhibit the polyubiquitination of AURKB and reduce the removal of AURKB from the centromeres by VCP, which is essential for SAC activation. SAC inactivation is common in BRCA2-deficient prostate cancer patients, but PP2A inhibitors could reactivate the SAC and achieve BRCA2-deficient prostate tumor synthetic lethality. Our research reveals the survival adaptation mechanism of BRCA2-deficient prostate tumor cells and provides different angles for exploring synthetic lethal inhibitors in addition to targeting DNA damage repair pathways.
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Affiliation(s)
- Jian Wang
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University International Cancer Institute, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Yuke Chen
- Department of Urology, Peking University First Hospital, Beijing, China
| | - Shiwei Li
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University International Cancer Institute, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Wanchang Liu
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University International Cancer Institute, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Xiao Albert Zhou
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University International Cancer Institute, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Yefei Luo
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University International Cancer Institute, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Zhanzhan Xu
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University International Cancer Institute, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Yundong Xiong
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University International Cancer Institute, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Kaiqi Cheng
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University International Cancer Institute, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Mingjian Ruan
- Department of Urology, Peking University First Hospital, Beijing, China
| | - Wei Yu
- Department of Urology, Peking University First Hospital, Beijing, China
| | - Xiaoman Li
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University International Cancer Institute, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Weibin Wang
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University International Cancer Institute, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Jiadong Wang
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University International Cancer Institute, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
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Leung W, Baxley RM, Traband E, Chang YC, Rogers CB, Wang L, Durrett W, Bromley KS, Fiedorowicz L, Thakar T, Tella A, Sobeck A, Hendrickson EA, Moldovan GL, Shima N, Bielinsky AK. FANCD2-dependent mitotic DNA synthesis relies on PCNA K164 ubiquitination. Cell Rep 2023; 42:113523. [PMID: 38060446 PMCID: PMC10842461 DOI: 10.1016/j.celrep.2023.113523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 10/09/2023] [Accepted: 11/15/2023] [Indexed: 12/30/2023] Open
Abstract
Ubiquitination of proliferating cell nuclear antigen (PCNA) at lysine 164 (K164) activates DNA damage tolerance pathways. Currently, we lack a comprehensive understanding of how PCNA K164 ubiquitination promotes genome stability. To evaluate this, we generated stable cell lines expressing PCNAK164R from the endogenous PCNA locus. Our data reveal that the inability to ubiquitinate K164 causes perturbations in global DNA replication. Persistent replication stress generates under-replicated regions and is exacerbated by the DNA polymerase inhibitor aphidicolin. We show that these phenotypes are due, in part, to impaired Fanconi anemia group D2 protein (FANCD2)-dependent mitotic DNA synthesis (MiDAS) in PCNAK164R cells. FANCD2 mono-ubiquitination is significantly reduced in PCNAK164R mutants, leading to reduced chromatin association and foci formation, both prerequisites for FANCD2-dependent MiDAS. Furthermore, K164 ubiquitination coordinates direct PCNA/FANCD2 colocalization in mitotic nuclei. Here, we show that PCNA K164 ubiquitination maintains human genome stability by promoting FANCD2-dependent MiDAS to prevent the accumulation of under-replicated DNA.
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Affiliation(s)
- Wendy Leung
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ryan M Baxley
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Emma Traband
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ya-Chu Chang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Colette B Rogers
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Liangjun Wang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Wesley Durrett
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kendall S Bromley
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
| | - Lidia Fiedorowicz
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
| | - Tanay Thakar
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Anika Tella
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Alexandra Sobeck
- Institute for Human Genetics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Eric A Hendrickson
- Department of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Naoko Shima
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA.
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44
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Xu R, Pan Z, Nakagawa T. Gross Chromosomal Rearrangement at Centromeres. Biomolecules 2023; 14:28. [PMID: 38254628 PMCID: PMC10813616 DOI: 10.3390/biom14010028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 01/24/2024] Open
Abstract
Centromeres play essential roles in the faithful segregation of chromosomes. CENP-A, the centromere-specific histone H3 variant, and heterochromatin characterized by di- or tri-methylation of histone H3 9th lysine (H3K9) are the hallmarks of centromere chromatin. Contrary to the epigenetic marks, DNA sequences underlying the centromere region of chromosomes are not well conserved through evolution. However, centromeres consist of repetitive sequences in many eukaryotes, including animals, plants, and a subset of fungi, including fission yeast. Advances in long-read sequencing techniques have uncovered the complete sequence of human centromeres containing more than thousands of alpha satellite repeats and other types of repetitive sequences. Not only tandem but also inverted repeats are present at a centromere. DNA recombination between centromere repeats can result in gross chromosomal rearrangement (GCR), such as translocation and isochromosome formation. CENP-A chromatin and heterochromatin suppress the centromeric GCR. The key player of homologous recombination, Rad51, safeguards centromere integrity through conservative noncrossover recombination between centromere repeats. In contrast to Rad51-dependent recombination, Rad52-mediated single-strand annealing (SSA) and microhomology-mediated end-joining (MMEJ) lead to centromeric GCR. This review summarizes recent findings on the role of centromere and recombination proteins in maintaining centromere integrity and discusses how GCR occurs at centromeres.
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Affiliation(s)
- Ran Xu
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
- Forefront Research Center, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
| | - Ziyi Pan
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
- Forefront Research Center, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
| | - Takuro Nakagawa
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
- Forefront Research Center, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
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45
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Wu Z, Gong Z, Li C, Huang Z. RTEL1 is upregulated in colorectal cancer and promotes tumor progression. Pathol Res Pract 2023; 252:154958. [PMID: 37988793 DOI: 10.1016/j.prp.2023.154958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 10/23/2023] [Accepted: 11/16/2023] [Indexed: 11/23/2023]
Abstract
As one of the most common cancers worldwide, the incidence of colorectal cancer (CRC) continues to increase. Metastasis is the leading cause of death for this malignant disease. Regulator of telomere elongation helicase 1 (RTEL1) is a key factor that maintains telomere stability and contributes to DNA repair. Recent advances have suggested that RTEL1 exerts other functions through various mechanisms. However, little is known about its role in human cancers, including CRC. In this study, we revealed that the copy number of RTEL1 was significantly higher in CRC tissues, especially in metastatic CRC tissues, than in paired normal tissues, which was associated with increased expression. Increased RTEL1 expression was significantly correlated with CRC progression and poor survival. Functionally, RTEL1 knockdown suppressed the proliferation and metastasis of CRC both in vitro and in vivo. In addition, multiple signalling pathways, including the mitotic cell cycle, DNA repair, and EMT, were potentially regulated by RTEL1. Notably, GPR17 appeared to be a candidate downstream target gene that partially mediated the tumor-promoting effects of RTEL1 in CRC. Altogether, our results indicate that RTEL1 plays a crucial role in CRC progression and appears to be a promising therapeutic target and prognosis for CRC.
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Affiliation(s)
- Zhuochao Wu
- Wuxi Cancer Institute, Affiliated Hospital of Jiangnan University, Wuxi 214062, Jiangsu, China; Laboratory of Cancer Epigenetics, Wuxi School of Medicine, Jiangnan University, Wuxi 214062, Jiangsu, China
| | - Zhicheng Gong
- Wuxi Cancer Institute, Affiliated Hospital of Jiangnan University, Wuxi 214062, Jiangsu, China; Laboratory of Cancer Epigenetics, Wuxi School of Medicine, Jiangnan University, Wuxi 214062, Jiangsu, China
| | - Chaoqun Li
- Wuxi Cancer Institute, Affiliated Hospital of Jiangnan University, Wuxi 214062, Jiangsu, China; Laboratory of Cancer Epigenetics, Wuxi School of Medicine, Jiangnan University, Wuxi 214062, Jiangsu, China
| | - Zhaohui Huang
- Wuxi Cancer Institute, Affiliated Hospital of Jiangnan University, Wuxi 214062, Jiangsu, China; Laboratory of Cancer Epigenetics, Wuxi School of Medicine, Jiangnan University, Wuxi 214062, Jiangsu, China.
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46
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Zhang X, Zhao Q, Wang T, Long Q, Sun Y, Jiao L, Gullerova M. DNA damage response, a double-edged sword for vascular aging. Ageing Res Rev 2023; 92:102137. [PMID: 38007046 DOI: 10.1016/j.arr.2023.102137] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 10/03/2023] [Accepted: 11/20/2023] [Indexed: 11/27/2023]
Abstract
Vascular aging is a major risk factor for age-related cardiovascular diseases, which have high rates of morbidity and mortality. It is characterized by changes in the blood vessels, such as macroscopically increased vascular diameter and intima-medial thickness, chronic inflammation, vascular calcification, arterial stiffening, and atherosclerosis. DNA damage and the subsequent various DNA damage response (DDR) pathways are important causative factors of vascular aging. Deficient DDR, which may result in the accumulation of unrepaired damaged DNA or mutations, can lead to vascular aging. On the other hand, over-activation of some DDR proteins, such as poly (ADP ribose) polymerase (PARP) and ataxia telangiectasia mutated (ATM), also can enhance the process of vascular aging, suggesting that DDR can have both positive and negative effects on vascular aging. Despite the evidence reviewed in this paper, the role of DDR in vascular aging and potential therapeutic targets remain poorly understood and require further investigation.
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Affiliation(s)
- Xiao Zhang
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom; Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China; China International Neuroscience Institute (China-INI), Beijing 100053, China
| | - Qing Zhao
- M.D. Program, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Tao Wang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China; China International Neuroscience Institute (China-INI), Beijing 100053, China
| | - Qilin Long
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Yixin Sun
- First Hospital, Peking University, Beijing, China
| | - Liqun Jiao
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China; China International Neuroscience Institute (China-INI), Beijing 100053, China; Department of Interventional Neuroradiology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
| | - Monika Gullerova
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom.
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47
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Abstract
Transcription and replication both require large macromolecular complexes to act on a DNA template, yet these machineries cannot simultaneously act on the same DNA sequence. Conflicts between the replication and transcription machineries (transcription-replication conflicts, or TRCs) are widespread in both prokaryotes and eukaryotes and have the capacity to both cause DNA damage and compromise complete, faithful replication of the genome. This review will highlight recent studies investigating the genomic locations of TRCs and the mechanisms by which they may be prevented, mitigated, or resolved. We address work from both model organisms and mammalian systems but predominantly focus on multicellular eukaryotes owing to the additional complexities inherent in the coordination of replication and transcription in the context of cell type-specific gene expression and higher-order chromatin organization.
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Affiliation(s)
- Liana Goehring
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, USA;
| | - Tony T Huang
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, USA;
| | - Duncan J Smith
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, USA;
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48
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Showman S, Talbert PB, Xu Y, Adeyemi RO, Henikoff S. Expansion of human centromeric arrays in cells undergoing break-induced replication. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.11.566714. [PMID: 38014305 PMCID: PMC10680626 DOI: 10.1101/2023.11.11.566714] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Human centromeres are located within α-satellite arrays and evolve rapidly, which can lead to individual variation in array lengths. Proposed mechanisms for such alterations in lengths are unequal cross-over between sister chromatids, gene conversion, and break-induced replication. However, the underlying molecular mechanisms responsible for the massive, complex, and homogeneous organization of centromeric arrays have not been experimentally validated. Here, we use droplet digital PCR assays to demonstrate that centromeric arrays can expand and contract within ~20 somatic cell divisions of a cell line. We find that the frequency of array variation among single-cell-derived subclones ranges from a minimum of ~7% to a maximum of ~100%. Further clonal evolution revealed that centromere expansion is favored over contraction. We find that the homologous recombination protein RAD52 and the helicase PIF1 are required for extensive array change, suggesting that centromere sequence evolution can occur via break-induced replication.
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Affiliation(s)
- Soyeon Showman
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Paul B. Talbert
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Yiling Xu
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Richard O. Adeyemi
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Steven Henikoff
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
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49
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Traband EL, Hammerlund SR, Shameem M, Narayan A, Ramana S, Tella A, Sobeck A, Shima N. Mitotic DNA Synthesis in Untransformed Human Cells Preserves Common Fragile Site Stability via a FANCD2-Driven Mechanism That Requires HELQ. J Mol Biol 2023; 435:168294. [PMID: 37777152 PMCID: PMC10839910 DOI: 10.1016/j.jmb.2023.168294] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 09/14/2023] [Accepted: 09/25/2023] [Indexed: 10/02/2023]
Abstract
Faithful genome duplication is a challenging task for dividing mammalian cells, particularly under replication stress where timely resolution of late replication intermediates (LRIs) becomes crucial prior to cell division. In human cancer cells, mitotic DNA repair synthesis (MiDAS) is described as a final mechanism for the resolution of LRIs to avoid lethal chromosome mis-segregation. RAD52-driven MiDAS achieves this mission in part by generating gaps/breaks on metaphase chromosomes, which preferentially occur at common fragile sites (CFS). We previously demonstrated that a MiDAS mechanism also exists in untransformed and primary human cells, which is RAD52 independent but requires FANCD2. However, the properties of this form of MiDAS are not well understood. Here, we report that FANCD2-driven MiDAS in untransformed human cells: 1) requires a prerequisite step of FANCD2 mono-ubiquitination by a subset of Fanconi anemia (FA) proteins, 2) primarily acts to preserve CFS stability but not to prevent chromosome mis-segregation, and 3) depends on HELQ, which potentially functions at an early step. Hence, FANCD2-driven MiDAS in untransformed cells is built to protect CFS stability, whereas RAD52-driven MiDAS in cancer cells is likely adapted to prevent chromosome mis-segregation at the cost of CFS expression. Notably, we also identified a novel form of MiDAS, which surfaces to function when FANCD2 is absent in untransformed cells. Our findings substantiate the complex nature of MiDAS and a link between its deficiencies and the pathogenesis of FA, a human genetic disease.
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Affiliation(s)
- Emma L Traband
- Department of Genetics, Cell Biology and Development, Medical School, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA; Department of Biochemistry, Molecular Biology, and Biophysics, College of Biological Sciences, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
| | - Sarah R Hammerlund
- Department of Genetics, Cell Biology and Development, Medical School, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA; Department of Biochemistry, Molecular Biology, and Biophysics, College of Biological Sciences, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
| | - Mohammad Shameem
- Department of Biochemistry, Molecular Biology, and Biophysics, College of Biological Sciences, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
| | - Ananya Narayan
- Department of Genetics, Cell Biology and Development, Medical School, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
| | - Sanjiv Ramana
- Department of Genetics, Cell Biology and Development, Medical School, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
| | - Anika Tella
- Department of Genetics, Cell Biology and Development, Medical School, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
| | - Alexandra Sobeck
- Department of Biochemistry, Molecular Biology, and Biophysics, College of Biological Sciences, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA; Masonic Cancer Center, Minneapolis, MN 55455, USA
| | - Naoko Shima
- Department of Genetics, Cell Biology and Development, Medical School, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA; Masonic Cancer Center, Minneapolis, MN 55455, USA.
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50
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Bhowmick R, Hickson ID, Liu Y. Completing genome replication outside of S phase. Mol Cell 2023; 83:3596-3607. [PMID: 37716351 DOI: 10.1016/j.molcel.2023.08.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/03/2023] [Accepted: 08/17/2023] [Indexed: 09/18/2023]
Abstract
Mitotic DNA synthesis (MiDAS) is an unusual form of DNA replication that occurs during mitosis. Initially, MiDAS was characterized as a process associated with intrinsically unstable loci known as common fragile sites that occurs after cells experience DNA replication stress (RS). However, it is now believed to be a more widespread "salvage" mechanism that is called upon to complete the duplication of any under-replicated genomic region. Emerging data suggest that MiDAS is a DNA repair process potentially involving two or more pathways working in parallel or sequentially. In this review, we introduce the causes of RS, regions of the human genome known to be especially vulnerable to RS, and the strategies used to complete DNA replication outside of S phase. Additionally, because MiDAS is a prominent feature of aneuploid cancer cells, we will discuss how targeting MiDAS might potentially lead to improvements in cancer therapy.
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Affiliation(s)
- Rahul Bhowmick
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200 Copenhagen N, Denmark; Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Ian D Hickson
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
| | - Ying Liu
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
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