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Rossetti GG, Dommann N, Karamichali A, Dionellis VS, Asensio Aldave A, Yarahmadov T, Rodriguez-Carballo E, Keogh A, Candinas D, Stroka D, Halazonetis TD. In vivo DNA replication dynamics unveil aging-dependent replication stress. Cell 2024:S0092-8674(24)00963-2. [PMID: 39293447 DOI: 10.1016/j.cell.2024.08.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 03/16/2024] [Accepted: 08/19/2024] [Indexed: 09/20/2024]
Abstract
The genome duplication program is affected by multiple factors in vivo, including developmental cues, genotoxic stress, and aging. Here, we monitored DNA replication initiation dynamics in regenerating livers of young and old mice after partial hepatectomy to investigate the impact of aging. In young mice, the origin firing sites were well defined; the majority were located 10-50 kb upstream or downstream of expressed genes, and their position on the genome was conserved in human cells. Old mice displayed the same replication initiation sites, but origin firing was inefficient and accompanied by a replication stress response. Inhibitors of the ATR checkpoint kinase fully restored origin firing efficiency in the old mice but at the expense of an inflammatory response and without significantly enhancing the fraction of hepatocytes entering the cell cycle. These findings unveil aging-dependent replication stress and a crucial role of ATR in mitigating the stress-associated inflammation, a hallmark of aging.
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Affiliation(s)
- Giacomo G Rossetti
- Department of Molecular and Cellular Biology, University of Geneva, Geneva 1205, Switzerland
| | - Noëlle Dommann
- Department of Visceral Surgery and Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Angeliki Karamichali
- Department of Molecular and Cellular Biology, University of Geneva, Geneva 1205, Switzerland
| | - Vasilis S Dionellis
- Department of Molecular and Cellular Biology, University of Geneva, Geneva 1205, Switzerland
| | - Ainhoa Asensio Aldave
- Department of Visceral Surgery and Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Tural Yarahmadov
- Department of Visceral Surgery and Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department for BioMedical Research, University of Bern, Bern, Switzerland
| | | | - Adrian Keogh
- Department of Visceral Surgery and Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Daniel Candinas
- Department of Visceral Surgery and Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Deborah Stroka
- Department of Visceral Surgery and Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department for BioMedical Research, University of Bern, Bern, Switzerland.
| | - Thanos D Halazonetis
- Department of Molecular and Cellular Biology, University of Geneva, Geneva 1205, Switzerland.
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2
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Bergis-Ser C, Reji M, Latrasse D, Bergounioux C, Benhamed M, Raynaud C. Chromatin dynamics and RNA metabolism are double-edged swords for the maintenance of plant genome integrity. NATURE PLANTS 2024; 10:857-873. [PMID: 38658791 DOI: 10.1038/s41477-024-01678-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 03/27/2024] [Indexed: 04/26/2024]
Abstract
Maintenance of genome integrity is an essential process in all organisms. Mechanisms avoiding the formation of DNA lesions or mutations are well described in animals because of their relevance to human health and cancer. In plants, they are of growing interest because DNA damage accumulation is increasingly recognized as one of the consequences of stress. Although the cellular response to DNA damage is mostly studied in response to genotoxic treatments, the main source of DNA lesions is cellular activity itself. This can occur through the production of reactive oxygen species as well as DNA processing mechanisms such as DNA replication or transcription and chromatin dynamics. In addition, how lesions are formed and repaired is greatly influenced by chromatin features and dynamics and by DNA and RNA metabolism. Notably, actively transcribed regions or replicating DNA, because they are less condensed and are sites of DNA processing, are more exposed to DNA damage. However, at the same time, a wealth of cellular mechanisms cooperate to favour DNA repair at these genomic loci. These intricate relationships that shape the distribution of mutations along the genome have been studied extensively in animals but much less in plants. In this Review, we summarize how chromatin dynamics influence lesion formation and DNA repair in plants, providing a comprehensive view of current knowledge and highlighting open questions with regard to what is known in other organisms.
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Affiliation(s)
- Clara Bergis-Ser
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France
| | - Meega Reji
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France
- Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, India
| | - David Latrasse
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France
| | - Catherine Bergounioux
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France
| | - Moussa Benhamed
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France
- Université Paris Cité, Institute of Plant Sciences Paris-Saclay, Gif-sur-Yvette, France
- Institut Universitaire de France, Orsay, France
| | - Cécile Raynaud
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France.
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3
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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 DOI: 10.1080/21541264.2024.2316965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [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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4
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Wang L. RNA polymerase collisions and their role in transcription. Transcription 2024; 15:38-47. [PMID: 38357902 DOI: 10.1080/21541264.2024.2316972] [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: 11/06/2023] [Accepted: 02/06/2024] [Indexed: 02/16/2024] Open
Abstract
RNA polymerases are the central enzymes of gene expression and function frequently in either a head-on or co-directional manner on the busy DNA track. Whether and how these collisions between RNA polymerases contribute to transcriptional regulation is mysterious. Increasing evidence from biochemical and single-molecule studies suggests that RNA polymerase collisions function as an important regulator to fine-tune transcription, rather than creating deleterious "traffic jams". This review summarizes the recent progress on elucidating the consequences of RNA polymerase collisions during transcription and highlights the significance of cooperation and coordination between RNA polymerases.
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Affiliation(s)
- Ling Wang
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
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5
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Fernandez HN, Kretsch AM, Kunakom S, Kadjo AE, Mitchell DA, Eustáquio AS. High-Yield Lasso Peptide Production in a Burkholderia Bacterial Host by Plasmid Copy Number Engineering. ACS Synth Biol 2024; 13:337-350. [PMID: 38194362 PMCID: PMC10947786 DOI: 10.1021/acssynbio.3c00597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
The knotted configuration of lasso peptides confers thermal stability and proteolytic resistance, addressing two shortcomings of peptide-based drugs. However, low isolation yields hinder the discovery and development of lasso peptides. While testing Burkholderia sp. FERM BP-3421 as a bacterial host to produce the lasso peptide capistruin, an overproducer clone was previously identified. In this study, we show that an increase in the plasmid copy number partially contributed to the overproducer phenotype. Further, we modulated the plasmid copy number to recapitulate titers to an average of 160% relative to the overproducer, which is 1000-fold higher than previously reported with E. coli, reaching up to 240 mg/L. To probe the applicability of the developed tools for lasso peptide discovery, we targeted a new lasso peptide biosynthetic gene cluster from endosymbiont Mycetohabitans sp. B13, leading to the isolation of mycetolassin-15 and mycetolassin-18 in combined titers of 11 mg/L. These results validate Burkholderia sp. FERM BP-3421 as a production platform for lasso peptide discovery.
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Affiliation(s)
- Hannah N. Fernandez
- Department of Pharmaceutical Sciences and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Ashley M. Kretsch
- Department of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Sylvia Kunakom
- Department of Pharmaceutical Sciences and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Adjo E. Kadjo
- Department of Pharmaceutical Sciences and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Douglas A. Mitchell
- Department of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Alessandra S. Eustáquio
- Department of Pharmaceutical Sciences and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
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6
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Liebau RC, Waters C, Ahmed A, Soni RK, Gautier J. Transcription-Coupled Repair of DNA Interstrand Crosslinks by UVSSA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.10.538304. [PMID: 37214867 PMCID: PMC10197625 DOI: 10.1101/2023.05.10.538304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
DNA interstrand crosslinks (ICLs) are covalent bonds between bases on opposing strands of the DNA helix which prevent DNA melting and subsequent DNA replication or RNA transcription. Here, we show that Ultraviolet Stimulated Scaffold Protein A (UVSSA) participates in transcription-coupled repair of ICLs in human cells. Inactivation of UVSSA sensitizes human cells to ICL-inducing drugs, and delays ICL repair. UVSSA is required for transcription-coupled repair of a single ICL in a fluorescence-based reporter assay. UVSSA localizes to chromatin following ICL damage, and interacts with transcribing Pol II, CSA, CSB, and TFIIH. Specifically, UVSSA interaction with TFIIH is required for ICL repair. Finally, UVSSA expression positively correlates with ICL chemotherapy resistance in human cancer cell lines. Our data strongly suggest that transcription-coupled ICL repair (TC-ICR) is a bona fide ICL repair mechanism that contributes to crosslinker drug resistance independently of replication-coupled ICL repair.
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Affiliation(s)
- Rowyn C Liebau
- Institute for Cancer Genetics, Graduate School of Arts and Sciences, Columbia University, New York, NY, 10027, United States of America
| | - Crystal Waters
- Institute of Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, United States of America
- Agilent Technologies, La Jolla CA, 92037, United States of America
| | - Arooba Ahmed
- Institute of Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, United States of America
| | - Rajesh K Soni
- Proteomics and Macromolecular Crystallography Shared Resource, Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY 10032, United States of America
| | - Jean Gautier
- Institute of Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, United States of America
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7
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Elsakrmy N, Cui H. R-Loops and R-Loop-Binding Proteins in Cancer Progression and Drug Resistance. Int J Mol Sci 2023; 24:ijms24087064. [PMID: 37108225 PMCID: PMC10138518 DOI: 10.3390/ijms24087064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/06/2023] [Accepted: 04/08/2023] [Indexed: 04/29/2023] Open
Abstract
R-loops are three-stranded DNA/RNA hybrids that form by the annealing of the mRNA transcript to its coding template while displacing the non-coding strand. While R-loop formation regulates physiological genomic and mitochondrial transcription and DNA damage response, imbalanced R-loop formation can be a threat to the genomic integrity of the cell. As such, R-loop formation is a double-edged sword in cancer progression, and perturbed R-loop homeostasis is observed across various malignancies. Here, we discuss the interplay between R-loops and tumor suppressors and oncogenes, with a focus on BRCA1/2 and ATR. R-loop imbalances contribute to cancer propagation and the development of chemotherapy drug resistance. We explore how R-loop formation can cause cancer cell death in response to chemotherapeutics and be used to circumvent drug resistance. As R-loop formation is tightly linked to mRNA transcription, their formation is unavoidable in cancer cells and can thus be explored in novel cancer therapeutics.
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Affiliation(s)
- Noha Elsakrmy
- Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada
| | - Haissi Cui
- Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada
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8
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Wang G, Vasquez KM. Dynamic alternative DNA structures in biology and disease. Nat Rev Genet 2023; 24:211-234. [PMID: 36316397 DOI: 10.1038/s41576-022-00539-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2022] [Indexed: 11/06/2022]
Abstract
Repetitive elements in the human genome, once considered 'junk DNA', are now known to adopt more than a dozen alternative (that is, non-B) DNA structures, such as self-annealed hairpins, left-handed Z-DNA, three-stranded triplexes (H-DNA) or four-stranded guanine quadruplex structures (G4 DNA). These dynamic conformations can act as functional genomic elements involved in DNA replication and transcription, chromatin organization and genome stability. In addition, recent studies have revealed a role for these alternative structures in triggering error-generating DNA repair processes, thereby actively enabling genome plasticity. As a driving force for genetic variation, non-B DNA structures thus contribute to both disease aetiology and evolution.
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Affiliation(s)
- Guliang Wang
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Paediatric Research Institute, Austin, TX, USA
| | - Karen M Vasquez
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Paediatric Research Institute, Austin, TX, USA.
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9
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Böhly N, Schmidt AK, Zhang X, Slusarenko BO, Hennecke M, Kschischo M, Bastians H. Increased replication origin firing links replication stress to whole chromosomal instability in human cancer. Cell Rep 2022; 41:111836. [PMID: 36516748 DOI: 10.1016/j.celrep.2022.111836] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 09/12/2022] [Accepted: 11/22/2022] [Indexed: 12/14/2022] Open
Abstract
Chromosomal instability (CIN) is a hallmark of cancer and comprises structural CIN (S-CIN) and numerical or whole chromosomal CIN (W-CIN). Recent work indicated that replication stress (RS), known to contribute to S-CIN, also affects mitotic chromosome segregation, possibly explaining the common co-existence of S-CIN and W-CIN in human cancer. Here, we show that RS-induced increased origin firing is sufficient to trigger W-CIN in human cancer cells. We discovered that overexpression of origin firing genes, including GINS1 and CDC45, correlates with W-CIN in human cancer specimens and causes W-CIN in otherwise chromosomally stable human cells. Furthermore, modulation of the ATR-CDK1-RIF1 axis increases the number of firing origins and leads to W-CIN. Importantly, chromosome missegregation upon additional origin firing is mediated by increased mitotic microtubule growth rates, a mitotic defect prevalent in chromosomally unstable cancer cells. Thus, our study identifies increased replication origin firing as a cancer-relevant trigger for chromosomal instability.
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Affiliation(s)
- Nicolas Böhly
- Georg August University Göttingen, University Medical Center Göttingen (UMG), Department of Molecular Oncology, Section for Cellular Oncology, 37077 Göttingen, Germany
| | - Ann-Kathrin Schmidt
- Georg August University Göttingen, University Medical Center Göttingen (UMG), Department of Molecular Oncology, Section for Cellular Oncology, 37077 Göttingen, Germany
| | - Xiaoxiao Zhang
- University of Applied Sciences Koblenz, Department of Mathematics and Technology, 53424 Remagen, Germany; Technical University of Munich, Department of Informatics, 81675 Munich, Germany
| | - Benjamin O Slusarenko
- Georg August University Göttingen, University Medical Center Göttingen (UMG), Department of Molecular Oncology, Section for Cellular Oncology, 37077 Göttingen, Germany
| | - Magdalena Hennecke
- Georg August University Göttingen, University Medical Center Göttingen (UMG), Department of Molecular Oncology, Section for Cellular Oncology, 37077 Göttingen, Germany
| | - Maik Kschischo
- University of Applied Sciences Koblenz, Department of Mathematics and Technology, 53424 Remagen, Germany
| | - Holger Bastians
- Georg August University Göttingen, University Medical Center Göttingen (UMG), Department of Molecular Oncology, Section for Cellular Oncology, 37077 Göttingen, Germany.
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10
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Shaw AE, Kairamkonda S, Ghodke H, Schauer GD. Biochemical and single-molecule techniques to study accessory helicase resolution of R-loop proteins at stalled replication forks. Methods Enzymol 2022; 673:191-225. [PMID: 35965008 DOI: 10.1016/bs.mie.2022.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
R-loop proteins present a stable and robust blockade to the progression of a DNA replication fork during S-phase. The consequences of this block can include mutagenesis and other irreversible chromosomal catastrophes, causing genomic instability and disease. As such, further investigation into the molecular mechanisms underlying R-loop protein resolution is warranted. The critical role of non-replicative accessory helicases in R-loop protein resolution has increasingly come into light in recent years. Such helicases include the Pif1-family, monomeric helicases that have been studied in many different contexts and that have been ascribed to a multitude of separable protective functions in the cell. In this chapter, we present protocols to study R-loop protein resolution by Pif1 helicase at stalled replication forks using purified proteins, both at the biochemical and single-molecule level. Our system uses recombinant proteins expressed in Saccharomyces cerevisiae but could apply to practically any organism of interest due to the high interspecies homology of the proteins involved in DNA replication. The methods we outline are extensible to many systems and should be applicable to studying R-loop clearance by any Superfamily (SF) 1B helicase. These techniques will further enable mechanistic research on these critical but understudied components of the genomic maintenance program.
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Affiliation(s)
- Alisa E Shaw
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Sreeya Kairamkonda
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Harshad Ghodke
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia; Illawarra Health & Medical Research Institute, Wollongong, NSW, Australia
| | - Grant D Schauer
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States.
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11
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Hicks T, Koury E, McCabe C, Williams C, Crahan C, Smolikove S. R-loop-induced irreparable DNA damage evades checkpoint detection in the C. elegans germline. Nucleic Acids Res 2022; 50:8041-8059. [PMID: 35871299 PMCID: PMC9371901 DOI: 10.1093/nar/gkac621] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 06/28/2022] [Accepted: 07/18/2022] [Indexed: 11/24/2022] Open
Abstract
Accumulation of DNA–RNA hybrids in the form of R-loops can result in replication–transcription conflict that leads to the formation of DNA double strand breaks (DSBs). Using null mutants for the two Caenorhabditis elegans genes encoding for RNaseH1 and RNaseH2, we identify novel effects of R-loop accumulation in the germline. R-loop accumulation leads, as expected, to replication stress, followed by the formation of DSBs. A subset of these DSBs are irreparable. However, unlike irreparable DSBs generated in other systems, which trigger permanent cell cycle arrest, germline irreparable DSBs are propagated to oocytes. Despite DNA damage checkpoint activation in the stem cell niche, the signaling cannot be sustained and nuclei with irreparable DNA damage progress into meiosis. Moreover, unlike other forms of DNA damage that increase germline apoptosis, R-loop-generated DSBs remain undetected by the apoptotic checkpoint. This coincides with attenuation of ATM/ATR signaling in mid-to-late meiotic prophase I. These data altogether indicate that in the germline, DSBs that are generated by R-loops can lead to irreparable DSBs that evade cellular machineries designed for damage recognition. These studies implicate germline R-loops as an especially dangerous driver of germline mutagenesis.
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Affiliation(s)
- Tara Hicks
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
| | - Emily Koury
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
| | - Caleb McCabe
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
| | - Cameron Williams
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
| | - Caroline Crahan
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
| | - Sarit Smolikove
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
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