1
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Coulson-Gilmer C, Littler S, Barnes B, Brady R, Anagho H, Pillay N, Dey M, Macmorland W, Bronder D, Nelson L, Tighe A, Lin WH, Morgan R, Unwin R, Nielsen M, McGrail J, Taylor S. Intrinsic PARG inhibitor sensitivity is mimicked by TIMELESS haploinsufficiency and rescued by nucleoside supplementation. NAR Cancer 2024; 6:zcae030. [PMID: 39015544 PMCID: PMC11249981 DOI: 10.1093/narcan/zcae030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 06/20/2024] [Accepted: 06/26/2024] [Indexed: 07/18/2024] Open
Abstract
A subset of cancer cells are intrinsically sensitive to inhibitors targeting PARG, the poly(ADP-ribose) glycohydrolase that degrades PAR chains. Sensitivity is accompanied by persistent DNA replication stress, and can be induced by inhibition of TIMELESS, a replisome accelerator. However, the nature of the vulnerability responsible for intrinsic sensitivity remains undetermined. To understand PARG activity dependency, we analysed Timeless model systems and intrinsically sensitive ovarian cancer cells. We show that nucleoside supplementation rescues all phenotypes associated with PARG inhibitor sensitivity, including replisome speed and fork stalling, S-phase completion and mitotic entry, proliferation dynamics and clonogenic potential. Importantly nucleoside supplementation restores PARG inhibitor resistance despite the continued presence of PAR chains, indicating that sensitivity does not correlate with PAR levels. In addition, we show that inhibition of thymidylate synthase, an enzyme required for dNTP homeostasis, induces PARG-dependency. Together, these observations suggest that PARG inhibitor sensitivity reflects an inability to control replisome speed and/or maintain helicase-polymerase coupling in response to nucleotide imbalances.
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Affiliation(s)
- Camilla Coulson-Gilmer
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - Samantha Littler
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - Bethany M Barnes
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - Rosie M Brady
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - Holda A Anagho
- Proteomics program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nisha Pillay
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - Malini Dey
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - William Macmorland
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - Daniel Bronder
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - Louisa Nelson
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - Anthony Tighe
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - Wei-Hsiang Lin
- Genome Editing Unit, Faculty of Biology, Medicine and Health, University of Manchester, Michael Smith Building, Dover Street, Manchester M13 9PT, UK
| | - Robert D Morgan
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
- Department of Medical Oncology, The Christie NHS Foundation Trust, Wilmslow Rd, Manchester M20 4BX, UK
| | - Richard D Unwin
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - Michael L Nielsen
- Proteomics program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Joanne C McGrail
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
| | - Stephen S Taylor
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester Cancer Research Centre, Wilmslow Road, Manchester M20 4GJ, UK
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2
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Prorok P, Wolf E, Cardoso MC. Timeless-Tipin interactions with MCM and RPA mediate DNA replication stress response. Front Cell Dev Biol 2024; 12:1346534. [PMID: 38487270 PMCID: PMC10939015 DOI: 10.3389/fcell.2024.1346534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 02/12/2024] [Indexed: 03/17/2024] Open
Abstract
The accuracy of replication is one of the most important mechanisms ensuring the stability of the genome. The fork protection complex prevents premature replisome stalling and/or premature disassembly upon stress. Here, we characterize the Timeless-Tipin complex, a component of the fork protection complex. We used microscopy approaches, including colocalization analysis and proximity ligation assay, to investigate the spatial localization of the complex during ongoing replication in human cells. Taking advantage of the replication stress induction and the ensuing polymerase-helicase uncoupling, we characterized the Timeless-Tipin localization within the replisome. Replication stress was induced using hydroxyurea (HU) and aphidicolin (APH). While HU depletes the substrate for DNA synthesis, APH binds directly inside the catalytic pocket of DNA polymerase and inhibits its activity. Our data revealed that the Timeless-Tipin complex, independent of the stress, remains bound on chromatin upon stress induction and progresses together with the replicative helicase. This is accompanied by the spatial dissociation of the complex from the blocked replication machinery. Additionally, after stress induction, Timeless interaction with RPA, which continuously accumulates on ssDNA, was increased. Taken together, the Timeless-Tipin complex acts as a universal guardian of the mammalian replisome in an unperturbed S-phase progression as well as during replication stress.
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Affiliation(s)
- Paulina Prorok
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Eva Wolf
- Institute of Molecular Physiology (IMP), Johannes Gutenberg-University Mainz, Mainz, Germany
| | - M. Cristina Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
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3
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Vipat S, Moiseeva TN. The TIMELESS Roles in Genome Stability and Beyond. J Mol Biol 2024; 436:168206. [PMID: 37481157 DOI: 10.1016/j.jmb.2023.168206] [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: 05/01/2023] [Revised: 06/20/2023] [Accepted: 07/12/2023] [Indexed: 07/24/2023]
Abstract
TIMELESS protein (TIM) protects replication forks from stalling at difficult-to-replicate regions and plays an important role in DNA damage response, including checkpoint signaling, protection of stalled replication forks and DNA repair. Loss of TIM causes severe replication stress, while its overexpression is common in various types of cancer, providing protection from DNA damage and resistance to chemotherapy. Although TIM has mostly been studied for its part in replication stress response, its additional roles in supporting genome stability and a wide variety of other cellular pathways are gradually coming to light. This review discusses the diverse functions of TIM and its orthologs in healthy and cancer cells, open questions, and potential future directions.
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Affiliation(s)
- Sameera Vipat
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn 12618, Estonia
| | - Tatiana N Moiseeva
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn 12618, Estonia.
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4
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Pollenus E, Possemiers H, Knoops S, Prenen F, Vandermosten L, Thienpont C, Abdurahiman S, Demeyer S, Cools J, Matteoli G, Vanoirbeek JAJ, Vande Velde G, Van den Steen PE. Single cell RNA sequencing reveals endothelial cell killing and resolution pathways in experimental malaria-associated acute respiratory distress syndrome. PLoS Pathog 2024; 20:e1011929. [PMID: 38236930 PMCID: PMC10826972 DOI: 10.1371/journal.ppat.1011929] [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: 10/03/2023] [Revised: 01/30/2024] [Accepted: 12/29/2023] [Indexed: 01/31/2024] Open
Abstract
Plasmodium parasites cause malaria, a global health disease that is responsible for more than 200 million clinical cases and 600 000 deaths each year. Most deaths are caused by various complications, including malaria-associated acute respiratory distress syndrome (MA-ARDS). Despite the very rapid and efficient killing of parasites with antimalarial drugs, 15% of patients with complicated malaria succumb. This stresses the importance of investigating resolution mechanisms that are involved in the recovery from these complications once the parasite is killed. To study the resolution of MA-ARDS, P. berghei NK65-infected C57BL/6 mice were treated with antimalarial drugs after onset of symptoms, resulting in 80% survival. Micro-computed tomography revealed alterations of the lungs upon infection, with an increase in total and non-aerated lung volume due to edema. Whole body plethysmography confirmed a drastically altered lung ventilation, which was restored during resolution. Single-cell RNA sequencing indicated an increased inflammatory state in the lungs upon infection, which was accompanied by a drastic decrease in endothelial cells, consistent with CD8+ T cell-mediated killing. During resolution, anti-inflammatory pathways were upregulated and proliferation of endothelial cells was observed. MultiNicheNet interactome analysis identified important changes in the ligand-receptor interactions during disease resolution that warrant further exploration in order to develop new therapeutic strategies. In conclusion, our study provides insights in pro-resolving pathways that limit inflammation and promote endothelial cell proliferation in experimental MA-ARDS. This information may be useful for the design of adjunctive treatments to enhance resolution after Plasmodium parasite killing by antimalarial drugs.
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Affiliation(s)
- Emilie Pollenus
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology & Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Hendrik Possemiers
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology & Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Sofie Knoops
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology & Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Fran Prenen
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology & Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Leen Vandermosten
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology & Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Chloë Thienpont
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology & Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Saeed Abdurahiman
- Laboratory of Mucosal Immunology, Translational Research in Gastro-Intestinal Disorders (TARGID), Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium
| | - Sofie Demeyer
- Laboratory of Molecular Biology of Leukemia, Department of Human Genetics, VIB—KU Leuven, Leuven, Belgium
| | - Jan Cools
- Laboratory of Molecular Biology of Leukemia, Department of Human Genetics, VIB—KU Leuven, Leuven, Belgium
| | - Gianluca Matteoli
- Laboratory of Mucosal Immunology, Translational Research in Gastro-Intestinal Disorders (TARGID), Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium
| | - Jeroen A. J. Vanoirbeek
- Centre for Environment and Health, Department of Public Health and Primary Care, KU Leuven, Leuven, Belgium
| | - Greetje Vande Velde
- Biomedical MRI, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Philippe E. Van den Steen
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology & Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
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5
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Patel JA, Zezelic C, Rageul J, Saldanha J, Khan A, Kim H. Replisome dysfunction upon inducible TIMELESS degradation synergizes with ATR inhibition to trigger replication catastrophe. Nucleic Acids Res 2023; 51:6246-6263. [PMID: 37144518 PMCID: PMC10325925 DOI: 10.1093/nar/gkad363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 03/29/2023] [Accepted: 04/26/2023] [Indexed: 05/06/2023] Open
Abstract
The structure of DNA replication forks is preserved by TIMELESS (TIM) in the fork protection complex (FPC) to support seamless fork progression. While the scaffolding role of the FPC to couple the replisome activity is much appreciated, the detailed mechanism whereby inherent replication fork damage is sensed and counteracted during DNA replication remains largely elusive. Here, we implemented an auxin-based degron system that rapidly triggers inducible proteolysis of TIM as a source of endogenous DNA replication stress and replisome dysfunction to dissect the signaling events that unfold at stalled forks. We demonstrate that acute TIM degradation activates the ATR-CHK1 checkpoint, whose inhibition culminates in replication catastrophe by single-stranded DNA accumulation and RPA exhaustion. Mechanistically, unrestrained replisome uncoupling, excessive origin firing, and aberrant reversed fork processing account for the synergistic fork instability. Simultaneous TIM loss and ATR inactivation triggers DNA-PK-dependent CHK1 activation, which is unexpectedly necessary for promoting fork breakage by MRE11 and catastrophic cell death. We propose that acute replisome dysfunction results in a hyper-dependency on ATR to activate local and global fork stabilization mechanisms to counteract irreversible fork collapse. Our study identifies TIM as a point of replication vulnerability in cancer that can be exploited with ATR inhibitors.
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Affiliation(s)
- Jinal A Patel
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Camryn Zezelic
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Julie Rageul
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Joanne Saldanha
- The Graduate program in Genetics, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Arafat Khan
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Hyungjin Kim
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
- Stony Brook Cancer Center, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY 11794, USA
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6
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Saldanha J, Rageul J, Patel JA, Kim H. The Adaptive Mechanisms and Checkpoint Responses to a Stressed DNA Replication Fork. Int J Mol Sci 2023; 24:10488. [PMID: 37445667 PMCID: PMC10341514 DOI: 10.3390/ijms241310488] [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: 05/26/2023] [Revised: 06/13/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
DNA replication is a tightly controlled process that ensures the faithful duplication of the genome. However, DNA damage arising from both endogenous and exogenous assaults gives rise to DNA replication stress associated with replication fork slowing or stalling. Therefore, protecting the stressed fork while prompting its recovery to complete DNA replication is critical for safeguarding genomic integrity and cell survival. Specifically, the plasticity of the replication fork in engaging distinct DNA damage tolerance mechanisms, including fork reversal, repriming, and translesion DNA synthesis, enables cells to overcome a variety of replication obstacles. Furthermore, stretches of single-stranded DNA generated upon fork stalling trigger the activation of the ATR kinase, which coordinates the cellular responses to replication stress by stabilizing the replication fork, promoting DNA repair, and controlling cell cycle and replication origin firing. Deregulation of the ATR checkpoint and aberrant levels of chronic replication stress is a common characteristic of cancer and a point of vulnerability being exploited in cancer therapy. Here, we discuss the various adaptive responses of a replication fork to replication stress and the roles of ATR signaling that bring fork stabilization mechanisms together. We also review how this knowledge is being harnessed for the development of checkpoint inhibitors to trigger the replication catastrophe of cancer cells.
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Affiliation(s)
- Joanne Saldanha
- The Graduate Program in Genetics, Stony Brook University, Stony Brook, NY 11794, USA
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Julie Rageul
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Jinal A Patel
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Hyungjin Kim
- The Graduate Program in Genetics, Stony Brook University, Stony Brook, NY 11794, USA
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
- Stony Brook Cancer Center, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
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7
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Patel JA, Kim H. The TIMELESS effort for timely DNA replication and protection. Cell Mol Life Sci 2023; 80:84. [PMID: 36892674 PMCID: PMC9998586 DOI: 10.1007/s00018-023-04738-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 02/16/2023] [Accepted: 02/24/2023] [Indexed: 03/10/2023]
Abstract
Accurate replication of the genome is fundamental to cellular survival and tumor prevention. The DNA replication fork is vulnerable to DNA lesions and damages that impair replisome progression, and improper control over DNA replication stress inevitably causes fork stalling and collapse, a major source of genome instability that fuels tumorigenesis. The integrity of the DNA replication fork is maintained by the fork protection complex (FPC), in which TIMELESS (TIM) constitutes a key scaffold that couples the CMG helicase and replicative polymerase activities, in conjunction with its interaction with other proteins associated with the replication machinery. Loss of TIM or the FPC in general results in impaired fork progression, elevated fork stalling and breakage, and a defect in replication checkpoint activation, thus underscoring its pivotal role in protecting the integrity of both active and stalled replication forks. TIM is upregulated in multiple cancers, which may represent a replication vulnerability of cancer cells that could be exploited for new therapies. Here, we discuss recent advances on our understanding of the multifaceted roles of TIM in DNA replication and stalled fork protection, and how its complex functions are engaged in collaboration with other genome surveillance and maintenance factors.
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Affiliation(s)
- Jinal A Patel
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Basic Sciences Tower 8-125, 101 Nicolls Rd, Stony Brook, NY, 11794, USA
| | - Hyungjin Kim
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Basic Sciences Tower 8-125, 101 Nicolls Rd, Stony Brook, NY, 11794, USA.
- Stony Brook Cancer Center and Renaissance School of Medicine, Stony Brook University, Basic Sciences Tower 8-125, 101 Nicolls Rd, Stony Brook, NY, 11794, USA.
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8
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Extended DNA binding interfaces beyond the canonical SAP domain contribute to the function of replication stress regulator SDE2 at DNA replication forks. J Biol Chem 2022; 298:102268. [PMID: 35850305 PMCID: PMC9399289 DOI: 10.1016/j.jbc.2022.102268] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/05/2022] [Accepted: 07/07/2022] [Indexed: 11/25/2022] Open
Abstract
Elevated DNA replication stress causes instability of the DNA replication fork and increased DNA mutations, which underlies tumorigenesis. The DNA replication stress regulator silencing-defective 2 (SDE2) is known to bind to TIMELESS (TIM), a protein of the fork protection complex, and enhances its stability, thereby supporting replisome activity at DNA replication forks. However, the DNA-binding activity of SDE2 is not well defined. Here, we structurally and functionally characterize a new conserved DNA-binding motif related to the SAP (SAF-A/B, Acinus, PIAS) domain in human SDE2 and establish its preference for ssDNA. Our NMR solution structure of the SDE2SAP domain reveals a helix-extended loop-helix core with the helices aligned parallel to each other, consistent with known canonical SAP folds. Notably, we have shown that the DNA interaction of this SAP domain extends beyond the core SAP domain and is augmented by two lysine residues in the C-terminal tail, which is uniquely positioned adjacent to the SAP motif and conserved in the pre-mRNA splicing factor SF3A3. Furthermore, we found that mutation in the SAP domain and extended C terminus not only disrupts ssDNA binding but also impairs TIM localization at replication forks, thus inhibiting efficient fork progression. Taken together, our results establish SDE2SAP as an essential element for SDE2 to exert its role in preserving replication fork integrity via fork protection complex regulation and highlight the structural diversity of the DNA–protein interactions achieved by a specialized DNA-binding motif.
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9
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Germline polymorphisms in genes maintaining the replication fork predict the efficacy of oxaliplatin and irinotecan in patients with metastatic colorectal cancer. Br J Cancer 2022; 126:72-78. [PMID: 34689170 PMCID: PMC8727586 DOI: 10.1038/s41416-021-01592-7] [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: 07/28/2021] [Revised: 09/27/2021] [Accepted: 10/06/2021] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND The TIMELESS-TIPIN complex protects the replication fork from replication stress induced by chemotherapeutic drugs. We hypothesised genetic polymorphisms of the TIMELESS-TIPIN complex may affect the response, progression-free survival (PFS), and overall survival (OS) of cytotoxic drugs in patients with metastatic colorectal cancer (mCRC). METHODS We analysed data from the MAVERICC trial, which compared FOLFOX/bevacizumab and FOLFIRI/bevacizumab in untreated patients with mCRC. Genomic DNA extracted from blood samples was genotyped using an OncoArray. Eight functional single nucleotide polymorphisms (SNPs) in TIMELESS and TIPIN were tested for associations with clinical outcomes. RESULTS In total, 324 patients were included (FOLFOX/bevacizumab arm, n = 161; FOLFIRI/bevacizumab arm, n = 163). In the FOLFOX/bevacizumab arm, no SNPs displayed confirmed associations with survival outcomes. In the FOLFIRI/bevacizumab arm, TIMELESS rs2291739 was significantly associated with OS in multivariate analysis (G/G vs. any A allele, hazard ratio = 3.06, 95% confidence interval = 1.49-6.25, p = 0.004). TIMELESS rs2291739 displayed significant interactions with treatment regarding both PFS and OS. CONCLUSIONS TIMELESS rs2291739 might have different effects on therapeutic efficacy between oxaliplatin- and irinotecan-based chemotherapies. Upon further validation, our findings may be useful for personalised approaches in the first-line treatment of mCRC.
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10
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van Schie JJM, de Lange J. The Interplay of Cohesin and the Replisome at Processive and Stressed DNA Replication Forks. Cells 2021; 10:3455. [PMID: 34943967 PMCID: PMC8700348 DOI: 10.3390/cells10123455] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/04/2021] [Accepted: 12/06/2021] [Indexed: 12/12/2022] Open
Abstract
The cohesin complex facilitates faithful chromosome segregation by pairing the sister chromatids after DNA replication until mitosis. In addition, cohesin contributes to proficient and error-free DNA replication. Replisome progression and establishment of sister chromatid cohesion are intimately intertwined processes. Here, we review how the key factors in DNA replication and cohesion establishment cooperate in unperturbed conditions and during DNA replication stress. We discuss the detailed molecular mechanisms of cohesin recruitment and the entrapment of replicated sister chromatids at the replisome, the subsequent stabilization of sister chromatid cohesion via SMC3 acetylation, as well as the role and regulation of cohesin in the response to DNA replication stress.
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Affiliation(s)
- Janne J. M. van Schie
- Cancer Center Amsterdam, Department of Human Genetics, Section Oncogenetics, Amsterdam University Medical Centers, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
| | - Job de Lange
- Cancer Center Amsterdam, Department of Human Genetics, Section Oncogenetics, Amsterdam University Medical Centers, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
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11
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Zhang H, Xue Y, Yang X, Liu J, Liu Q. Toxoplasma gondii UBL-UBA shuttle proteins regulate several important cellular processes. FASEB J 2021; 35:e21898. [PMID: 34727385 DOI: 10.1096/fj.202100662rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 08/06/2021] [Accepted: 08/18/2021] [Indexed: 11/11/2022]
Abstract
Toxoplasma gondii is an obligate intracellular apicomplexan parasite causing lethal diseases in immunocompromised patients. UBL-UBA shuttle proteins (DDI1, RAD23, and DSK2) are important components of the ubiquitin-proteasome system. By degrading ubiquitinated proteins, UBL-UBA shuttle proteins regulate many cellular processes. However, the specific processes regulated by UBL-UBA shuttle proteins remain elusive. Here, we revealed that the deletion of shuttle proteins results in a selective accumulation of ubiquitinated proteins in the nucleus and aberrant DNA replication. ROP18 was mistargeted and accumulated in the shuttle protein mutant strain, resulting in the recruitment of immunity-related GTPases to the parasitophorous vacuole membrane (PVM). Furthermore, the mistargeting of ROP18 and the recruitment of Irgb6 to the PVM were also observed in the DDI1 mutant strain. DDI1 is a nonclassical UBL-UBA shuttle protein homologous to the HIV-1 protease. Molecular docking showed that DDI1 was a potential target of HIV-1 protease inhibitors. However, these inhibitors blocked the growth of T gondii in vitro but not in vivo. In conclusion, the Toxoplasma UBL-UBA shuttle protein regulates several important cellular processes and the mistargeting of ROP18 may be a representative of the abnormal homeostasis caused by shuttle protein mutation.
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Affiliation(s)
- Heng Zhang
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yangfei Xue
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xu Yang
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jing Liu
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Qun Liu
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
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12
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Cai YD, Chiu JC. Timeless in animal circadian clocks and beyond. FEBS J 2021; 289:6559-6575. [PMID: 34699674 PMCID: PMC9038958 DOI: 10.1111/febs.16253] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 10/09/2021] [Accepted: 10/26/2021] [Indexed: 12/13/2022]
Abstract
TIMELESS (TIM) was first identified as a molecular cog in the Drosophila circadian clock. Almost three decades of investigations have resulted in an insightful model describing the critical role of Drosophila TIM (dTIM) in circadian timekeeping in insects, including its function in mediating light entrainment and temperature compensation of the molecular clock. Furthermore, exciting discoveries on its sequence polymorphism and thermosensitive alternative RNA splicing have also established its role in regulating seasonal biology. Although mammalian TIM (mTIM), its mammalian paralog, was first identified as a potential circadian clock component in 1990s due to sequence similarity to dTIM, its role in clock regulation has been more controversial. Mammalian TIM has now been characterized as a DNA replication fork component and has been shown to promote fork progression and participate in cell cycle checkpoint signaling in response to DNA damage. Despite defective circadian rhythms displayed by mtim mutants, it remains controversial whether the regulation of circadian clocks by mTIM is direct, especially given the interconnection between the cell cycle and circadian clocks. In this review, we provide a historical perspective on the identification of animal tim genes, summarize the roles of TIM proteins in biological timing and genomic stability, and draw parallels between dTIM and mTIM despite apparent functional divergence.
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Affiliation(s)
- Yao D Cai
- Department of Entomology and Nematology, College of Agricultural and Environmental Sciences, University of California Davis, CA, USA
| | - Joanna C Chiu
- Department of Entomology and Nematology, College of Agricultural and Environmental Sciences, University of California Davis, CA, USA
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13
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Aricthota S, Haldar D. DDK/Hsk1 phosphorylates and targets fission yeast histone deacetylase Hst4 for degradation to stabilize stalled DNA replication forks. eLife 2021; 10:70787. [PMID: 34608864 PMCID: PMC8565929 DOI: 10.7554/elife.70787] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 10/01/2021] [Indexed: 01/01/2023] Open
Abstract
In eukaryotes, paused replication forks are prone to collapse, which leads to genomic instability, a hallmark of cancer. Dbf4-dependent kinase (DDK)/Hsk1Cdc7 is a conserved replication initiator kinase with conflicting roles in replication stress response. Here, we show that fission yeast DDK/Hsk1 phosphorylates sirtuin, Hst4 upon replication stress at C-terminal serine residues. Phosphorylation of Hst4 by DDK marks it for degradation via the ubiquitin ligase SCFpof3. Phosphorylation-defective hst4 mutant (4SA-hst4) displays defective recovery from replication stress, faulty fork restart, slow S-phase progression and decreased viability. The highly conserved fork protection complex (FPC) stabilizes stalled replication forks. We found that the recruitment of FPC components, Swi1 and Mcl1 to the chromatin is compromised in the 4SA-hst4 mutant, although whole cell levels increased. These defects are dependent upon H3K56ac and independent of intra S-phase checkpoint activation. Finally, we show conservation of H3K56ac-dependent regulation of Timeless, Tipin, and And-1 in human cells. We propose that degradation of Hst4 via DDK increases H3K56ac, changing the chromatin state in the vicinity of stalled forks facilitating recruitment and function of FPC. Overall, this study identified a crucial role of DDK and FPC in the regulation of replication stress response with implications in cancer therapeutics.
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Affiliation(s)
- Shalini Aricthota
- Laboratory of Chromatin Biology and Epigenetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.,Graduate Studies, Manipal Academy of Higher Education, Manipal, India
| | - Devyani Haldar
- Laboratory of Chromatin Biology and Epigenetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
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14
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Shyian M, Shore D. Approaching Protein Barriers: Emerging Mechanisms of Replication Pausing in Eukaryotes. Front Cell Dev Biol 2021; 9:672510. [PMID: 34124054 PMCID: PMC8194067 DOI: 10.3389/fcell.2021.672510] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/03/2021] [Indexed: 11/13/2022] Open
Abstract
During nuclear DNA replication multiprotein replisome machines have to jointly traverse and duplicate the total length of each chromosome during each cell cycle. At certain genomic locations replisomes encounter tight DNA-protein complexes and slow down. This fork pausing is an active process involving recognition of a protein barrier by the approaching replisome via an evolutionarily conserved Fork Pausing/Protection Complex (FPC). Action of the FPC protects forks from collapse at both programmed and accidental protein barriers, thus promoting genome integrity. In addition, FPC stimulates the DNA replication checkpoint and regulates topological transitions near the replication fork. Eukaryotic cells have been proposed to employ physiological programmed fork pausing for various purposes, such as maintaining copy number at repetitive loci, precluding replication-transcription encounters, regulating kinetochore assembly, or controlling gene conversion events during mating-type switching. Here we review the growing number of approaches used to study replication pausing in vivo and in vitro as well as the characterization of additional factors recently reported to modulate fork pausing in different systems. Specifically, we focus on the positive role of topoisomerases in fork pausing. We describe a model where replisome progression is inherently cautious, which ensures general preservation of fork stability and genome integrity but can also carry out specialized functions at certain loci. Furthermore, we highlight classical and novel outstanding questions in the field and propose venues for addressing them. Given how little is known about replisome pausing at protein barriers in human cells more studies are required to address how conserved these mechanisms are.
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Affiliation(s)
- Maksym Shyian
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland
| | - David Shore
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland
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15
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Pescatori S, Berardinelli F, Albanesi J, Ascenzi P, Marino M, Antoccia A, di Masi A, Acconcia F. A Tale of Ice and Fire: The Dual Role for 17β-Estradiol in Balancing DNA Damage and Genome Integrity. Cancers (Basel) 2021; 13:1583. [PMID: 33808099 PMCID: PMC8036963 DOI: 10.3390/cancers13071583] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 12/21/2022] Open
Abstract
17β-estradiol (E2) regulates human physiology both in females and in males. At the same time, E2 acts as a genotoxic substance as it could induce DNA damages, causing the initiation of cellular transformation. Indeed, increased E2 plasma levels are a risk factor for the development of several types of cancers including breast cancer. This paradoxical identity of E2 undermines the foundations of the physiological definition of "hormone" as E2 works both as a homeostatic regulator of body functions and as a genotoxic compound. Here, (i) the molecular circuitries underlying this double face of E2 are reviewed, and (ii) a possible framework to reconcile the intrinsic discrepancies of the E2 function is reported. Indeed, E2 is a regulator of the DNA damage response, which this hormone exploits to calibrate its genotoxicity with its physiological effects. Accordingly, the genes required to maintain genome integrity belong to the E2-controlled cellular signaling network and are essential for the appearance of the E2-induced cellular effects. This concept requires an "upgrade" to the vision of E2 as a "genotoxic hormone", which balances physiological and detrimental pathways to guarantee human body homeostasis. Deregulation of this equilibrium between cellular pathways would determine the E2 pathological effects.
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Affiliation(s)
- Sara Pescatori
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy; (S.P.); (F.B.); (J.A.); (P.A.); (M.M.)
| | - Francesco Berardinelli
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy; (S.P.); (F.B.); (J.A.); (P.A.); (M.M.)
- Neurodevelopment, Neurogenetics and Molecular Neurobiology Unit, IRCCS Santa Lucia Foundation, 00143 Rome, Italy
| | - Jacopo Albanesi
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy; (S.P.); (F.B.); (J.A.); (P.A.); (M.M.)
| | - Paolo Ascenzi
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy; (S.P.); (F.B.); (J.A.); (P.A.); (M.M.)
- Neuroendocrinology, Metabolism and Neuropharmacology Unit, IRCCS Santa Lucia Foundation, 00143 Rome, Italy
| | - Maria Marino
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy; (S.P.); (F.B.); (J.A.); (P.A.); (M.M.)
- Neuroendocrinology, Metabolism and Neuropharmacology Unit, IRCCS Santa Lucia Foundation, 00143 Rome, Italy
| | - Antonio Antoccia
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy; (S.P.); (F.B.); (J.A.); (P.A.); (M.M.)
| | - Alessandra di Masi
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy; (S.P.); (F.B.); (J.A.); (P.A.); (M.M.)
| | - Filippo Acconcia
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy; (S.P.); (F.B.); (J.A.); (P.A.); (M.M.)
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16
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Liu J, Liu S, Yang X. Construction of Gene Modules and Analysis of Prognostic Biomarkers for Cervical Cancer by Weighted Gene Co-Expression Network Analysis. Front Oncol 2021; 11:542063. [PMID: 33816217 PMCID: PMC8016394 DOI: 10.3389/fonc.2021.542063] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 01/26/2021] [Indexed: 11/29/2022] Open
Abstract
Background Despite advances in the understanding of neoplasm, patients with cervical cancer still have a poor prognosis. Identifying prognostic markers of cervical cancer may enable early detection of recurrence and more effective treatment. Methods Gene expression profiling data were acquired from the Gene Expression Omnibus database. After data normalization, genes with large variation were screened out. Next, we built co-expression modules by using weighted gene co-expression network analysis to investigate the relationship between the modules and clinical traits related to cervical cancer progression. Functional enrichment analysis was also applied on these co-expressed genes. We integrated the genes into a human protein-protein interaction (PPI) network to expand seed genes and build a co-expression network. For further analysis of the dataset, the Cancer Genome Atlas (TCGA) database was used to identify seed genes and their correlation to cervical cancer prognosis. Verification was further conducted by qPCR and the Human Protein Atlas (HPA) database to measure the expression of hub genes. Results Using WGCNA, we identified 25 co-expression modules from 10,016 genes in 128 human cervical cancer samples. After functional enrichment analysis, the magenta, brown, and darkred modules were selected as the three most correlated modules for cancer progression. Additionally, seed genes in the three modules were combined with a PPI network to identify 31 tumor-specific genes. Hierarchical clustering and Gepia results indicated that the expression quantity of hub genes NDC80, TIPIN, MCM3, MCM6, POLA1, and PRC1 may determine the prognosis of cervical cancer. Finally, TIPIN and POLA1 were further filtered by a LASSO model. In addition, their expression was identified by immunohistochemistry in HPA database as well as a biological experiment. Conclusion Our research provides a co-expression network of gene modules and identifies TIPIN and POLA1 as stable potential prognostic biomarkers for cervical cancer.
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Affiliation(s)
- Jiamei Liu
- Department of Pathology, The Shengjing Hospital of China Medical University, Shenyang, China
| | - Shengye Liu
- Department of Orthopedics, The Shengjing Hospital of China Medical University, Shenyang, China
| | - Xianghong Yang
- Department of Pathology, The Shengjing Hospital of China Medical University, Shenyang, China
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17
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Li B, Mu L, Li Y, Xia K, Yang Y, Aman S, Ahmad B, Li S, Wu H. TIMELESS inhibits breast cancer cell invasion and metastasis by down-regulating the expression of MMP9. Cancer Cell Int 2021; 21:38. [PMID: 33430865 PMCID: PMC7798230 DOI: 10.1186/s12935-021-01752-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 01/02/2021] [Indexed: 12/20/2022] Open
Abstract
Breast cancer is the first killer leading to female death, and tumor metastasis is one of the important factors leading to the death of patients, but the specific mechanism of breast cancer metastasis is not very clear at present. Our study showed that overexpression of TIMELESS could significantly inhibit the invasion and metastasis of breast cancer cells ZR-75-30 and the assembly of F-actin protein. On the contrary, knockdown of TIMELESS promoted the invasion and metastasis of breast cancer cells. Further study revealed that TIMELESS overexpression decreased the mRNA and protein levels of MMP9. Furthermore, TIMELESS could interact with p65, leading to repress the association of p65 and its acetyltransferase CBP and down-regulating the acetylation level of p65, which inhibited the activation of NF-κB signal pathway. In conclusion, our research showed that TIMELESS may repress the invasion and metastasis of breast cancer cells via inhibiting the acetylation of p65, inhibiting the activation of NF-κB, thus down-regulating the expression of MMP9, and then inhibiting the invasion and metastasis of breast cancer cells.
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Affiliation(s)
- Bowen Li
- School of Bioengineering & Key Laboratory of Protein Modification and Disease, Liaoning Province, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, Liaoning, China
| | - Liying Mu
- School of Bioengineering & Key Laboratory of Protein Modification and Disease, Liaoning Province, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, Liaoning, China
| | - Yanan Li
- School of Bioengineering & Key Laboratory of Protein Modification and Disease, Liaoning Province, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, Liaoning, China
| | - Kangkai Xia
- School of Bioengineering & Key Laboratory of Protein Modification and Disease, Liaoning Province, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, Liaoning, China
| | - Yuxi Yang
- School of Bioengineering & Key Laboratory of Protein Modification and Disease, Liaoning Province, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, Liaoning, China
| | - Sattout Aman
- School of Bioengineering & Key Laboratory of Protein Modification and Disease, Liaoning Province, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, Liaoning, China
| | - Bashir Ahmad
- School of Bioengineering & Key Laboratory of Protein Modification and Disease, Liaoning Province, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, Liaoning, China
| | - Shujing Li
- School of Bioengineering & Key Laboratory of Protein Modification and Disease, Liaoning Province, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, Liaoning, China.
| | - Huijian Wu
- School of Bioengineering & Key Laboratory of Protein Modification and Disease, Liaoning Province, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, Liaoning, China.
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18
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Westhorpe R, Keszthelyi A, Minchell NE, Jones D, Baxter J. Separable functions of Tof1/Timeless in intra-S-checkpoint signalling, replisome stability and DNA topological stress. Nucleic Acids Res 2020; 48:12169-12187. [PMID: 33166393 PMCID: PMC7708041 DOI: 10.1093/nar/gkaa963] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 10/06/2020] [Accepted: 10/09/2020] [Indexed: 12/16/2022] Open
Abstract
The highly conserved Tof1/Timeless proteins minimise replication stress and promote normal DNA replication. They are required to mediate the DNA replication checkpoint (DRC), the stable pausing of forks at protein fork blocks, the coupling of DNA helicase and polymerase functions during replication stress (RS) and the preferential resolution of DNA topological stress ahead of the fork. Here we demonstrate that the roles of the Saccharomyces cerevisiae Timeless protein Tof1 in DRC signalling and resolution of DNA topological stress require distinct N and C terminal regions of the protein, whereas the other functions of Tof1 are closely linked to the stable interaction between Tof1 and its constitutive binding partner Csm3/Tipin. By separating the role of Tof1 in DRC from fork stabilisation and coupling, we show that Tof1 has distinct activities in checkpoint activation and replisome stability to ensure the viable completion of DNA replication following replication stress.
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Affiliation(s)
- Rose Westhorpe
- Genome Damage and Stability Centre, School of Life Sciences, Science Park Road, University of Sussex, Falmer, Brighton, East Sussex BN1 9RQ, UK
| | - Andrea Keszthelyi
- Genome Damage and Stability Centre, School of Life Sciences, Science Park Road, University of Sussex, Falmer, Brighton, East Sussex BN1 9RQ, UK
| | - Nicola E Minchell
- Genome Damage and Stability Centre, School of Life Sciences, Science Park Road, University of Sussex, Falmer, Brighton, East Sussex BN1 9RQ, UK
| | - David Jones
- Genome Damage and Stability Centre, School of Life Sciences, Science Park Road, University of Sussex, Falmer, Brighton, East Sussex BN1 9RQ, UK
| | - Jonathan Baxter
- Genome Damage and Stability Centre, School of Life Sciences, Science Park Road, University of Sussex, Falmer, Brighton, East Sussex BN1 9RQ, UK
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19
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Rageul J, Park JJ, Zeng PP, Lee EA, Yang J, Hwang S, Lo N, Weinheimer AS, Schärer OD, Yeo JE, Kim H. SDE2 integrates into the TIMELESS-TIPIN complex to protect stalled replication forks. Nat Commun 2020; 11:5495. [PMID: 33127907 PMCID: PMC7603486 DOI: 10.1038/s41467-020-19162-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 09/28/2020] [Indexed: 01/07/2023] Open
Abstract
Protecting replication fork integrity during DNA replication is essential for maintaining genome stability. Here, we report that SDE2, a PCNA-associated protein, plays a key role in maintaining active replication and counteracting replication stress by regulating the replication fork protection complex (FPC). SDE2 directly interacts with the FPC component TIMELESS (TIM) and enhances its stability, thereby aiding TIM localization to replication forks and the coordination of replisome progression. Like TIM deficiency, knockdown of SDE2 leads to impaired fork progression and stalled fork recovery, along with a failure to activate CHK1 phosphorylation. Moreover, loss of SDE2 or TIM results in an excessive MRE11-dependent degradation of reversed forks. Together, our study uncovers an essential role for SDE2 in maintaining genomic integrity by stabilizing the FPC and describes a new role for TIM in protecting stalled replication forks. We propose that TIM-mediated fork protection may represent a way to cooperate with BRCA-dependent fork stabilization. The fork protection complex (FPC), including the proteins TIMELESS and TIPIN, stabilizes the replisome to ensure unperturbed fork progression during DNA replication. Here the authors reveal that that SDE2, a PCNA-associated protein, plays an important role in maintaining active replication and protecting stalled forks by regulating the replication fork protection complex (FPC).
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Affiliation(s)
- Julie Rageul
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, New York, 11794, USA
| | - Jennifer J Park
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, New York, 11794, USA
| | - Ping Ping Zeng
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, New York, 11794, USA
| | - Eun-A Lee
- Center for Genomic Integrity, Institute for Basic Science, Ulsan, 44919, Republic of Korea
| | - Jihyeon Yang
- Center for Genomic Integrity, Institute for Basic Science, Ulsan, 44919, Republic of Korea
| | - Sunyoung Hwang
- Center for Genomic Integrity, Institute for Basic Science, Ulsan, 44919, Republic of Korea
| | - Natalie Lo
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, New York, 11794, USA
| | - Alexandra S Weinheimer
- Department of Biochemistry and Cell Biology, State University of New York at Stony Brook, Stony Brook, New York, 11794, USA
| | - Orlando D Schärer
- Center for Genomic Integrity, Institute for Basic Science, Ulsan, 44919, Republic of Korea.,Department of Biological Sciences, School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea
| | - Jung-Eun Yeo
- Center for Genomic Integrity, Institute for Basic Science, Ulsan, 44919, Republic of Korea.
| | - Hyungjin Kim
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, New York, 11794, USA. .,Stony Brook Cancer Center, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York, 11794, USA.
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20
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Lerner LK, Holzer S, Kilkenny ML, Šviković S, Murat P, Schiavone D, Eldridge CB, Bittleston A, Maman JD, Branzei D, Stott K, Pellegrini L, Sale JE. Timeless couples G-quadruplex detection with processing by DDX11 helicase during DNA replication. EMBO J 2020; 39:e104185. [PMID: 32705708 PMCID: PMC7506991 DOI: 10.15252/embj.2019104185] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 06/25/2020] [Accepted: 06/26/2020] [Indexed: 12/27/2022] Open
Abstract
Regions of the genome with the potential to form secondary DNA structures pose a frequent and significant impediment to DNA replication and must be actively managed in order to preserve genetic and epigenetic integrity. How the replisome detects and responds to secondary structures is poorly understood. Here, we show that a core component of the fork protection complex in the eukaryotic replisome, Timeless, harbours in its C-terminal region a previously unappreciated DNA-binding domain that exhibits specific binding to G-quadruplex (G4) DNA structures. We show that this domain contributes to maintaining processive replication through G4-forming sequences, and exhibits partial redundancy with an adjacent PARP-binding domain. Further, this function of Timeless requires interaction with and activity of the helicase DDX11. Loss of both Timeless and DDX11 causes epigenetic instability at G4-forming sequences and DNA damage. Our findings indicate that Timeless contributes to the ability of the replisome to sense replication-hindering G4 formation and ensures the prompt resolution of these structures by DDX11 to maintain processive DNA synthesis.
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Affiliation(s)
- Leticia K Lerner
- MRC Laboratory of Molecular BiologyCambridgeUK
- Present address:
Centre de Recherche des CordeliersCell Death and Drug Resistance in Hematological Disorders TeamINSERM UMRS 1138Sorbonne UniversitéParisFrance
| | - Sandro Holzer
- Department of BiochemistryUniversity of CambridgeCambridgeUK
| | | | | | | | | | | | | | - Joseph D Maman
- Department of BiochemistryUniversity of CambridgeCambridgeUK
| | - Dana Branzei
- IFOMFondazione Italiana per la Ricerca sul CancroInstitute of Molecular OncologyMilanItaly
| | - Katherine Stott
- Department of BiochemistryUniversity of CambridgeCambridgeUK
| | - Luca Pellegrini
- Department of BiochemistryUniversity of CambridgeCambridgeUK
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21
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Grabarczyk DB. Crystal structure and interactions of the Tof1-Csm3 (Timeless-Tipin) fork protection complex. Nucleic Acids Res 2020; 48:6996-7004. [PMID: 32469068 PMCID: PMC7337906 DOI: 10.1093/nar/gkaa456] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 05/14/2020] [Accepted: 05/20/2020] [Indexed: 11/13/2022] Open
Abstract
The Tof1-Csm3 fork protection complex has a central role in the replisome-it promotes the progression of DNA replication forks and protects them when they stall, while also enabling cohesion establishment and checkpoint responses. Here, I present the crystal structure of the Tof1-Csm3 complex from Chaetomium thermophilum at 3.1 Å resolution. The structure reveals that both proteins together form an extended alpha helical repeat structure, which suggests a mechanical or scaffolding role for the complex. Expanding on this idea, I characterize a DNA interacting region and a cancer-associated Mrc1 binding site. This study provides the molecular basis for understanding the functions of the Tof1-Csm3 complex, its human orthologue the Timeless-Tipin complex and additionally the Drosophila circadian rhythm protein Timeless.
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Affiliation(s)
- Daniel B Grabarczyk
- Rudolf Virchow Center for Experimental Biomedicine, Institute for Structural Biology, University of Würzburg, Josef-Schneider-Str. 2, Würzburg, Germany
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22
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Zhou J, Zhang Y, Zou X, Kuai L, Wang L, Wang J, Shen F, Hu J, Zhang X, Huang Y, Chen Y. Aberrantly Expressed Timeless Regulates Cell Proliferation and Cisplatin Efficacy in Cervical Cancer. Hum Gene Ther 2020; 31:385-395. [PMID: 31870179 DOI: 10.1089/hum.2019.080] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Timeless is a regulator of molecular clockwork in Drosophila and related to cancer development in mammals. This study aimed to investigate the effect of Timeless on cell proliferation and cisplatin sensitivity in cervical cancer. Timeless expression was determined by bioinformatics analysis, immunohistochemistry, and quantitative polymerase chain reaction (qPCR). Chromatin immunoprecipitation assays and reporter gene assays were applied to determine the transcriptional factor contributing to Timeless upregulation. The effects of Timeless depletion on cell proliferation and cisplatin sensitivity were determined through in vitro and in vivo experiments. Cell apoptosis and senescence were assessed by flow cytometry and β-galactosidase staining. DNA damage and DNA repair pathways were determined by comet assay, immunofluorescent staining, and Western blot analysis. Timeless is aberrantly expressed in ∼52.5% of cervical cancer tissues. E2F1 and E2F4 contribute to the transcriptional activation of Timeless. Timeless depletion inhibits cell proliferation and increases cisplatin sensitivity in vitro and in vivo. Knockdown of Timeless induces cell apoptosis and cell senescence. Mechanically, Timeless silencing leads to DNA damage and impairs the activation of the ATR/CHK1 pathway in response to cisplatin in cervical cancer. Timeless is overexpressed in cervical cancer and regulates cell proliferation and cisplatin sensitivity, presenting an attractive target for cisplatin sensitizer in cervical cancer.
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Affiliation(s)
- Jinhua Zhou
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, China.,Clinical Research Center of Obstetrics and Gynecology, Jiangsu Key Laboratory of Clinical Immunology, Soochow University, Suzhou, China.,Jiangsu Institute of Clinical Immunology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Yinghui Zhang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xinwei Zou
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Lingling Kuai
- Department of Obstetrics and Gynecology, Nanjing Maternity and Child Health Hospital, Nanjing, China
| | - Li Wang
- Department of Gynecology and Obstetrics, Changzhou Maternal and Child Health Care Hospital Affiliated Nanjing Medical University, Changzhou, China
| | - Juan Wang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Fangrong Shen
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jinghui Hu
- Department of Gynecology, The First Affiliated Hospital of Zhejiang University Medical College, Hangzhou, China
| | - Xia Zhang
- Department of Obstetrics and Gynecology, TuHa Petroleum Hospital, Xinjiang, China
| | - Yazhen Huang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Youguo Chen
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, China.,Clinical Research Center of Obstetrics and Gynecology, Jiangsu Key Laboratory of Clinical Immunology, Soochow University, Suzhou, China.,Jiangsu Institute of Clinical Immunology, The First Affiliated Hospital of Soochow University, Suzhou, China
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23
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Zou X, Zhu C, Zhang L, Zhang Y, Fu F, Chen Y, Zhou J. MicroRNA-708 Suppresses Cell Proliferation and Enhances Chemosensitivity of Cervical Cancer Cells to cDDP by Negatively Targeting Timeless. Onco Targets Ther 2020; 13:225-235. [PMID: 32021269 PMCID: PMC6966141 DOI: 10.2147/ott.s227015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 11/22/2019] [Indexed: 01/10/2023] Open
Abstract
Purpose Cervical cancer is the fourth most common cause of cancer-associated mortality in women worldwide. Previous studies have reported that microRNAs (miRNAs) are involved in multiple biological aspects of cancer progression by regulating gene expression. Here, we investigated the role of microRNA-708 (miR-708) in cervical cancer. Methods The expression levels of miR-708 in cervical cancer tissues and paired-normal cervical tissues were tested by quantitative polymerase chain reaction (qPCR). The interaction between miR-708 and Timeless was identified by bioinformatics method, dual-luciferase reporter assay, and Western blotting. The effects of over-expression of miR-708 on cell proliferation and cisplatin sensitivity were determined by Cell Counting Kit-8 (CCK-8) and colony formation assay. Cell cycle and apoptosis were analyzed by flow cytometry. DNA damage induced by over-expression of miR-708 was determined by comet assay. Expression levels of the genes involved in repair of DNA damage were analyzed by Western blotting. Results MiR-708 was down-regulated in cervical cancer tissues compared with paired-normal cervical tissues. By bioinformatics method, Western blotting, and dual-luciferase reporter assay, we found that Timeless was a direct target of miR-708. Furthermore, miR-708 suppressed cellular viability, colony formation, promoted apoptosis, and induced DNA damage levels. MiR-708 also enhanced chemosensitivity of cervical cancer cells to cDDP via impairing the ATR/CHK1 signaling pathway. Conclusion We conclude that miR-708 suppresses cell proliferation, facilitates cisplatin efficacy, and impairs DNA repair pathway in cervical cancer cells. These results demonstrate that miR-708 might be a candidate therapeutic target for future cervical cancer therapy.
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Affiliation(s)
- Xinwei Zou
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China.,Clinical Research Center of Obstetrics and Gynecology, Jiangsu Key Laboratory of Clinical Immunology, Soochow University, Suzhou, People's Republic of China.,Jiangsu Institute of Clinical Immunology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Chenjie Zhu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China.,Clinical Research Center of Obstetrics and Gynecology, Jiangsu Key Laboratory of Clinical Immunology, Soochow University, Suzhou, People's Republic of China.,Jiangsu Institute of Clinical Immunology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Lin Zhang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Yi Zhang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Fengqing Fu
- Clinical Research Center of Obstetrics and Gynecology, Jiangsu Key Laboratory of Clinical Immunology, Soochow University, Suzhou, People's Republic of China.,Jiangsu Institute of Clinical Immunology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Youguo Chen
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China.,Clinical Research Center of Obstetrics and Gynecology, Jiangsu Key Laboratory of Clinical Immunology, Soochow University, Suzhou, People's Republic of China.,Jiangsu Institute of Clinical Immunology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Jinhua Zhou
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China.,Clinical Research Center of Obstetrics and Gynecology, Jiangsu Key Laboratory of Clinical Immunology, Soochow University, Suzhou, People's Republic of China.,Jiangsu Institute of Clinical Immunology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
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24
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Pavey S, Pinder A, Fernando W, D'Arcy N, Matigian N, Skalamera D, Lê Cao KA, Loo-Oey D, Hill MM, Stark M, Kimlin M, Burgess A, Cloonan N, Sturm RA, Gabrielli B. Multiple interaction nodes define the postreplication repair response to UV-induced DNA damage that is defective in melanomas and correlated with UV signature mutation load. Mol Oncol 2019; 14:22-41. [PMID: 31733171 PMCID: PMC6944116 DOI: 10.1002/1878-0261.12601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 11/06/2019] [Accepted: 11/14/2019] [Indexed: 01/25/2023] Open
Abstract
Ultraviolet radiation‐induced DNA mutations are a primary environmental driver of melanoma. The reason for this very high level of unrepaired DNA lesions leading to these mutations is still poorly understood. The primary DNA repair mechanism for UV‐induced lesions, that is, the nucleotide excision repair pathway, appears intact in most melanomas. We have previously reported a postreplication repair mechanism that is commonly defective in melanoma cell lines. Here we have used a genome‐wide approach to identify the components of this postreplication repair mechanism. We have used differential transcript polysome loading to identify transcripts that are associated with UV response, and then functionally assessed these to identify novel components of this repair and cell cycle checkpoint network. We have identified multiple interaction nodes, including global genomic nucleotide excision repair and homologous recombination repair, and previously unexpected MASTL pathway, as components of the response. Finally, we have used bioinformatics to assess the contribution of dysregulated expression of these pathways to the UV signature mutation load of a large melanoma cohort. We show that dysregulation of the pathway, especially the DNA damage repair components, are significant contributors to UV mutation load, and that dysregulation of the MASTL pathway appears to be a significant contributor to high UV signature mutation load.
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Affiliation(s)
- Sandra Pavey
- Diamantina Institute, TRI, The University of Queensland, Woolloongabba, QLD, Australia
| | - Alex Pinder
- Diamantina Institute, TRI, The University of Queensland, Woolloongabba, QLD, Australia
| | - Winnie Fernando
- Mater Research, TRI, The University of Queensland, Woolloongabba, QLD, Australia
| | - Nicholas D'Arcy
- Mater Research, TRI, The University of Queensland, Woolloongabba, QLD, Australia
| | - Nicholas Matigian
- Diamantina Institute, TRI, The University of Queensland, Woolloongabba, QLD, Australia.,QFAB Bioinformatics, The University of Queensland, Brisbane, QLD, Australia
| | - Dubravka Skalamera
- Diamantina Institute, TRI, The University of Queensland, Woolloongabba, QLD, Australia.,Mater Research, TRI, The University of Queensland, Woolloongabba, QLD, Australia
| | - Kim-Anh Lê Cao
- Diamantina Institute, TRI, The University of Queensland, Woolloongabba, QLD, Australia
| | - Dorothy Loo-Oey
- Diamantina Institute, TRI, The University of Queensland, Woolloongabba, QLD, Australia
| | - Michelle M Hill
- Diamantina Institute, TRI, The University of Queensland, Woolloongabba, QLD, Australia.,QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Mitchell Stark
- Diamantina Institute, TRI, The University of Queensland, Woolloongabba, QLD, Australia
| | - Michael Kimlin
- University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | | | - Nicole Cloonan
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Richard A Sturm
- Diamantina Institute, TRI, The University of Queensland, Woolloongabba, QLD, Australia
| | - Brian Gabrielli
- Diamantina Institute, TRI, The University of Queensland, Woolloongabba, QLD, Australia.,Mater Research, TRI, The University of Queensland, Woolloongabba, QLD, Australia
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25
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Shyian M, Albert B, Zupan AM, Ivanitsa V, Charbonnet G, Dilg D, Shore D. Fork pausing complex engages topoisomerases at the replisome. Genes Dev 2019; 34:87-98. [PMID: 31805522 PMCID: PMC6938670 DOI: 10.1101/gad.331868.119] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 11/07/2019] [Indexed: 12/22/2022]
Abstract
In this study, Shyian et al. set out to address mechanistically how the evolutionarily conserved fork pausing complex acts at proteinaceous replication fork barriers (RFBs) to promote fork passage and genome stability. Using several molecular and cell-based assays, the authors propose that forks pause at proteinaceous RFBs through a “sTOP” mechanism (“slowing down with topoisomerases I–II”), which also contributes to protecting cells from topoisomerase-blocking agents. Replication forks temporarily or terminally pause at hundreds of hard-to-replicate regions around the genome. A conserved pair of budding yeast replisome components Tof1–Csm3 (fission yeast Swi1–Swi3 and human TIMELESS–TIPIN) act as a “molecular brake” and promote fork slowdown at proteinaceous replication fork barriers (RFBs), while the accessory helicase Rrm3 assists the replisome in removing protein obstacles. Here we show that the Tof1–Csm3 complex promotes fork pausing independently of Rrm3 helicase by recruiting topoisomerase I (Top1) to the replisome. Topoisomerase II (Top2) partially compensates for the pausing decrease in cells when Top1 is lost from the replisome. The C terminus of Tof1 is specifically required for Top1 recruitment to the replisome and fork pausing but not for DNA replication checkpoint (DRC) activation. We propose that forks pause at proteinaceous RFBs through a “sTOP” mechanism (“slowing down with topoisomerases I–II”), which we show also contributes to protecting cells from topoisomerase-blocking agents.
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Affiliation(s)
- Maksym Shyian
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva 4, CH-1211, Switzerland
| | - Benjamin Albert
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva 4, CH-1211, Switzerland
| | - Andreja Moset Zupan
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva 4, CH-1211, Switzerland
| | - Vitalii Ivanitsa
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva 4, CH-1211, Switzerland
| | - Gabriel Charbonnet
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva 4, CH-1211, Switzerland
| | - Daniel Dilg
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva 4, CH-1211, Switzerland
| | - David Shore
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva 4, CH-1211, Switzerland
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26
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Utani K, Aladjem MI. Extra View: Sirt1 Acts As A Gatekeeper Of Replication Initiation To Preserve Genomic Stability. Nucleus 2019; 9:261-267. [PMID: 29578371 PMCID: PMC5973197 DOI: 10.1080/19491034.2018.1456218] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Since the discovery of a yeast gene silencing modifier (Silent Information Modifier 2, SIR2) and its role in maintaining genomic stability more than two decades ago, SIR2 homologs (sirtuins) were identified in diverse species. Sirtuins are protein deacetylases that play diverse roles in proper cellular metabolism including cell cycle progression and maintenance of genomic stability. In yeast, SIR2 interacts with replication origins and protein complexes that affect both replication origin usage and gene silencing. In metazoans, the largest SIR2 homolog, SIRT1, is implicated in epigenetic modifications, circadian signaling, DNA recombination and DNA repair. Until recently, very few studies investigated the role of mammalian SIRT1 in modulating DNA replication. We discuss a newly characterized interaction between human SIRT1 and the DNA replication machinery, reviewing data from recent studies that have investigated how complex signaling pathways that involve SIRT1 affect cellular growth regulatory circuits.
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Affiliation(s)
- Koichi Utani
- a Department of Microbiology , Kanazawa Medical University , Uchinada Ishikawa , Japan
| | - Mirit I Aladjem
- b Developmental Therapeutics Branch, Center for Cancer Research , NCI, NIH , Bethesda , MD , USA
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27
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Gellon L, Kaushal S, Cebrián J, Lahiri M, Mirkin SM, Freudenreich CH. Mrc1 and Tof1 prevent fragility and instability at long CAG repeats by their fork stabilizing function. Nucleic Acids Res 2019; 47:794-805. [PMID: 30476303 PMCID: PMC6344861 DOI: 10.1093/nar/gky1195] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 11/13/2018] [Indexed: 12/14/2022] Open
Abstract
Fork stabilization at DNA impediments is key to maintaining replication fork integrity and preventing chromosome breaks. Mrc1 and Tof1 are two known stabilizers that travel with the replication fork. In addition to a structural role, Mrc1 has a DNA damage checkpoint function. Using a yeast model system, we analyzed the role of Mrc1 and Tof1 at expanded CAG repeats of medium and long lengths, which are known to stall replication forks and cause trinucleotide expansion diseases such as Huntington's disease and myotonic dystrophy. We demonstrate that the fork stabilizer but not the checkpoint activation function of Mrc1 is key for preventing DNA breakage and death of cells containing expanded CAG tracts. In contrast, both Mrc1 functions are important in preventing repeat length instability. Mrc1 has a general fork protector role that is evident at forks traversing both repetitive and non-repetitive DNA, though it becomes crucial at long CAG repeat lengths. In contrast, the role of Tof1 in preventing fork breakage is specific to long CAG tracts of 85 or more repeats. Our results indicate that long CAG repeats have a particular need for Tof1 and highlight the importance of fork stabilizers in maintaining fork integrity during replication of structure-forming repeats.
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Affiliation(s)
- Lionel Gellon
- Department of Biology, Tufts University, Suite 4700, 200 Boston Ave, Medford, MA 02155, USA
| | - Simran Kaushal
- Department of Biology, Tufts University, Suite 4700, 200 Boston Ave, Medford, MA 02155, USA
| | - Jorge Cebrián
- Department of Biology, Tufts University, Suite 4700, 200 Boston Ave, Medford, MA 02155, USA
| | - Mayurika Lahiri
- Department of Biology, Tufts University, Suite 4700, 200 Boston Ave, Medford, MA 02155, USA
| | - Sergei M Mirkin
- Department of Biology, Tufts University, Suite 4700, 200 Boston Ave, Medford, MA 02155, USA
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28
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Bianco JN, Bergoglio V, Lin YL, Pillaire MJ, Schmitz AL, Gilhodes J, Lusque A, Mazières J, Lacroix-Triki M, Roumeliotis TI, Choudhary J, Moreaux J, Hoffmann JS, Tourrière H, Pasero P. Overexpression of Claspin and Timeless protects cancer cells from replication stress in a checkpoint-independent manner. Nat Commun 2019; 10:910. [PMID: 30796221 PMCID: PMC6385232 DOI: 10.1038/s41467-019-08886-8] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 02/05/2019] [Indexed: 12/31/2022] Open
Abstract
Oncogene-induced replication stress (RS) promotes cancer development but also impedes tumor growth by activating anti-cancer barriers. To determine how cancer cells adapt to RS, we have monitored the expression of different components of the ATR-CHK1 pathway in primary tumor samples. We show that unlike upstream components of the pathway, the checkpoint mediators Claspin and Timeless are overexpressed in a coordinated manner. Remarkably, reducing the levels of Claspin and Timeless in HCT116 cells to pretumoral levels impeded fork progression without affecting checkpoint signaling. These data indicate that high level of Claspin and Timeless increase RS tolerance by protecting replication forks in cancer cells. Moreover, we report that primary fibroblasts adapt to oncogene-induced RS by spontaneously overexpressing Claspin and Timeless, independently of ATR signaling. Altogether, these data indicate that enhanced levels of Claspin and Timeless represent a gain of function that protects cancer cells from of oncogene-induced RS in a checkpoint-independent manner.
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Affiliation(s)
- Julien N Bianco
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labellisée Ligue Contre le Cancer, 34396, Montpellier, France.,Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Str. 26, 50931, Cologne, Germany
| | - Valérie Bergoglio
- Cancer Research Center of Toulouse, INSERM U1037, CNRS ERL5294, University of Toulouse 3, 31037, Toulouse, France
| | - Yea-Lih Lin
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labellisée Ligue Contre le Cancer, 34396, Montpellier, France
| | - Marie-Jeanne Pillaire
- Cancer Research Center of Toulouse, INSERM U1037, CNRS ERL5294, University of Toulouse 3, 31037, Toulouse, France
| | - Anne-Lyne Schmitz
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labellisée Ligue Contre le Cancer, 34396, Montpellier, France
| | - Julia Gilhodes
- Clinical trials Office - Biostatistics Unit, Institute Claudius Regaud, Institute Universitaire du Cancer Toulouse-Oncopole (IUCT-O), 31100, Toulouse, France
| | - Amelie Lusque
- Clinical trials Office - Biostatistics Unit, Institute Claudius Regaud, Institute Universitaire du Cancer Toulouse-Oncopole (IUCT-O), 31100, Toulouse, France
| | - Julien Mazières
- Thoracic Oncology Department, Toulouse University Hospital, University Paul Sabatier, 31062, Toulouse, France
| | | | | | | | - Jérôme Moreaux
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labellisée Ligue Contre le Cancer, 34396, Montpellier, France
| | - Jean-Sébastien Hoffmann
- Cancer Research Center of Toulouse, INSERM U1037, CNRS ERL5294, University of Toulouse 3, 31037, Toulouse, France
| | - Hélène Tourrière
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labellisée Ligue Contre le Cancer, 34396, Montpellier, France.
| | - Philippe Pasero
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labellisée Ligue Contre le Cancer, 34396, Montpellier, France.
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29
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Neilsen BK, Frodyma DE, McCall JL, Fisher KW, Lewis RE. ERK-mediated TIMELESS expression suppresses G2/M arrest in colon cancer cells. PLoS One 2019; 14:e0209224. [PMID: 30629587 PMCID: PMC6328106 DOI: 10.1371/journal.pone.0209224] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/30/2018] [Indexed: 01/04/2023] Open
Abstract
The cell cycle is under circadian regulation. Oncogenes can dysregulate circadian-regulated genes to disrupt the cell cycle, promoting tumor cell proliferation. As a regulator of G2/M arrest in response to DNA damage, the circadian gene Timeless Circadian Clock (TIMELESS) coordinates this connection and is a potential locus for oncogenic manipulation. TIMELESS expression was evaluated using RNASeq data from TCGA and by RT-qPCR and western blot analysis in a panel of colon cancer cell lines. TIMELESS expression following ERK inhibition was examined via western blot. Cell metabolic capacity, propidium iodide, and CFSE staining were used to evaluate the effect of TIMELESS depletion on colon cancer cell survival and proliferation. Cell metabolic capacity following TIMELESS depletion in combination with Wee1 or CHK1 inhibition was assessed. TIMELESS is overexpressed in cancer and required for increased cancer cell proliferation. ERK activation promotes TIMELESS expression. TIMELESS depletion increases γH2AX, a marker of DNA damage, and triggers G2/M arrest via increased CHK1 and CDK1 phosphorylation. TIMELESS depletion in combination with Wee1 or CHK1 inhibition causes an additive decrease in cancer cell metabolic capacity with limited effects in non-transformed human colon epithelial cells. The data show that ERK activation contributes to the overexpression of TIMELESS in cancer. Depletion of TIMELESS increases γH2AX and causes G2/M arrest, limiting cell proliferation. These results demonstrate a role for TIMELESS in cancer and encourage further examination of the link between circadian rhythm dysregulation and cancer cell proliferation.
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Affiliation(s)
- Beth K. Neilsen
- Eppley Institute, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Danielle E. Frodyma
- Eppley Institute, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Jamie L. McCall
- Eppley Institute, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Kurt W. Fisher
- Eppley Institute, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Robert E. Lewis
- Eppley Institute, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail:
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30
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Mazzoccoli G, Colangelo T, Panza A, Rubino R, Tiberio C, Palumbo O, Carella M, Trombetta D, Gentile A, Tavano F, Valvano MR, Storlazzi CT, Macchia G, De Cata A, Bisceglia G, Capocefalo D, Colantuoni V, Sabatino L, Piepoli A, Mazza T. Analysis of clock gene-miRNA correlation networks reveals candidate drivers in colorectal cancer. Oncotarget 2018; 7:45444-45461. [PMID: 27323779 PMCID: PMC5216733 DOI: 10.18632/oncotarget.9989] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 05/29/2016] [Indexed: 12/20/2022] Open
Abstract
Altered functioning of the biological clock is involved in cancer onset and progression. MicroRNAs (miRNAs) interact with the clock genes modulating the function of genetically encoded molecular clockworks. Collaborative interactions may take place within the coding-noncoding RNA regulatory networks. We aimed to evaluate the cross-talk among miRNAs and clock genes in colorectal cancer (CRC). We performed an integrative analysis of miRNA-miRNA and miRNA-mRNA interactions on high-throughput molecular profiling of matched human CRC tissue and non-tumor mucosa, pinpointing core clock genes and their targeting miRNAs. Data obtained in silico were validated in CRC patients and human colon cancer cell lines. In silico we found severe alterations of clock gene–related coding-noncoding RNA regulatory networks in tumor tissues, which were later corroborated by the analysis of human CRC specimens and experiments performed in vitro. In conclusion, specific miRNAs target and regulate the transcription/translation of clock genes and clock gene-related miRNA-miRNA as well as mRNA-miRNA interactions are altered in colorectal cancer. Exploration of the interplay between specific miRNAs and genes, which are critically involved in the functioning of the biological clock, provides a better understanding of the importance of the miRNA-clock genes axis and its derangement in colorectal cancer.
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Affiliation(s)
- Gianluigi Mazzoccoli
- Division of Internal Medicine and Chronobiology Unit, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Tommaso Colangelo
- Department of Sciences and Technologies, University of Sannio, Benevento, Italy
| | - Anna Panza
- Division of Gastroenterology and Research Laboratory, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Rosa Rubino
- Division of Internal Medicine and Chronobiology Unit, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Cristiana Tiberio
- Division of Internal Medicine and Chronobiology Unit, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Orazio Palumbo
- Medical Genetics Service, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Massimo Carella
- Medical Genetics Service, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Domenico Trombetta
- Oncology-Research Laboratory, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Annamaria Gentile
- Division of Gastroenterology and Research Laboratory, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Francesca Tavano
- Division of Gastroenterology and Research Laboratory, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Maria Rosa Valvano
- Division of Gastroenterology and Research Laboratory, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | | | - Gemma Macchia
- Department of Biology, University of Bari, Bari, Italy
| | - Angelo De Cata
- Division of Internal Medicine and Chronobiology Unit, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Giovanni Bisceglia
- Department of Surgical Sciences, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Daniele Capocefalo
- Bioinformatics Unit, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Vittorio Colantuoni
- Department of Sciences and Technologies, University of Sannio, Benevento, Italy
| | - Lina Sabatino
- Department of Sciences and Technologies, University of Sannio, Benevento, Italy
| | - Ada Piepoli
- Division of Epidemiology and Health Statistics, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
| | - Tommaso Mazza
- Bioinformatics Unit, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy
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31
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Scherr MJ, Safaric B, Duderstadt KE. Noise in the Machine: Alternative Pathway Sampling is the Rule During DNA Replication. Bioessays 2017; 40. [PMID: 29282758 DOI: 10.1002/bies.201700159] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/01/2017] [Indexed: 11/07/2022]
Abstract
The astonishing efficiency and accuracy of DNA replication has long suggested that refined rules enforce a single highly reproducible sequence of molecular events during the process. This view was solidified by early demonstrations that DNA unwinding and synthesis are coupled within a stable molecular factory, known as the replisome, which consists of conserved components that each play unique and complementary roles. However, recent single-molecule observations of replisome dynamics have begun to challenge this view, revealing that replication may not be defined by a uniform sequence of events. Instead, multiple exchange pathways, pauses, and DNA loop types appear to dominate replisome function. These observations suggest we must rethink our fundamental assumptions and acknowledge that each replication cycle may involve sampling of alternative, sometimes parallel, pathways. Here, we review our current mechanistic understanding of DNA replication while highlighting findings that exemplify multi-pathway aspects of replisome function and considering the broader implications.
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Affiliation(s)
- Matthias J Scherr
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Barbara Safaric
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Karl E Duderstadt
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany.,Physik Department, Technische Universität München, Garching, Germany
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32
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Kottemann MC, Conti BA, Lach FP, Smogorzewska A. Removal of RTF2 from Stalled Replisomes Promotes Maintenance of Genome Integrity. Mol Cell 2017; 69:24-35.e5. [PMID: 29290612 DOI: 10.1016/j.molcel.2017.11.035] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 09/25/2017] [Accepted: 11/29/2017] [Indexed: 11/27/2022]
Abstract
The protection and efficient restart of stalled replication forks is critical for the maintenance of genome integrity. Here, we identify a regulatory pathway that promotes stalled forks recovery from replication stress. We show that the mammalian replisome component C20orf43/RTF2 (homologous to S. pombe Rtf2) must be removed for fork restart to be optimal. We further show that the proteasomal shuttle proteins DDI1 and DDI2 are required for RTF2 removal from stalled forks. Persistence of RTF2 at stalled forks results in fork restart defects, hyperactivation of the DNA damage signal, accumulation of single-stranded DNA (ssDNA), sensitivity to replication drugs, and chromosome instability. These results establish that RTF2 removal is a key determinant for the ability of cells to manage replication stress and maintain genome integrity.
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Affiliation(s)
- Molly C Kottemann
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY 10065, USA
| | - Brooke A Conti
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY 10065, USA
| | - Francis P Lach
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY 10065, USA
| | - Agata Smogorzewska
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY 10065, USA.
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33
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Zhang ZX, Zhang J, Cao Q, Campbell JL, Lou H. The DNA Pol ϵ stimulatory activity of Mrc1 is modulated by phosphorylation. Cell Cycle 2017; 17:64-72. [PMID: 29157061 DOI: 10.1080/15384101.2017.1403680] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
DNA replication checkpoint (Mec1-Mrc1-Rad53 in budding yeast) is an evolutionarily conserved surveillance system to ensure proper DNA replication and genome stability in all eukaryotes. Compared to its well-known function as a mediator of replication checkpoint, the exact role of Mrc1 as a component of normal replication forks remains relatively unclear. In this study, we provide in vitro biochemical evidence to support that yeast Mrc1 is able to enhance the activity of DNA polymerase ϵ (Pol ϵ), the major leading strand replicase. Mrc1 can selectively bind avidly to primer/template DNA bearing a single-stranded region, but not to double-stranded DNA (dsDNA). Mutations of the lysine residues within basic patch 1 (BP1) compromise both DNA binding and polymerase stimulatory activities. Interestingly, Mrc1-3D, a mutant mimicking phosphorylation by the Hog1/MAPK kinase during the osmotic stress response, retains DNA binding but not polymerase stimulation. The stimulatory effect is also abrogated in Mrc1 purified from cells treated with hydroxyurea (HU), which elicits replication checkpoint activation. Taken together with previous findings, these results imply that under unperturbed condition, Mrc1 has a DNA synthesis stimulatory activity, which can be eliminated via Mrc1 phosphorylation in response to replication and/or osmotic stresses.
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Affiliation(s)
- Zhong-Xin Zhang
- a Beijing Advanced Innovation Center for Food Nutrition and Human Health , State Key Laboratory of Agrobiotechnology , MOA Key Laboratory of Soil Microbiology , College of Biological Sciences , China Agricultural University , Beijing 100193 , China
| | - Jingjing Zhang
- a Beijing Advanced Innovation Center for Food Nutrition and Human Health , State Key Laboratory of Agrobiotechnology , MOA Key Laboratory of Soil Microbiology , College of Biological Sciences , China Agricultural University , Beijing 100193 , China
| | - Qinhong Cao
- a Beijing Advanced Innovation Center for Food Nutrition and Human Health , State Key Laboratory of Agrobiotechnology , MOA Key Laboratory of Soil Microbiology , College of Biological Sciences , China Agricultural University , Beijing 100193 , China
| | - Judith L Campbell
- b Braun Laboratories , California Institute of Technology , Pasadena , CA 91125 , USA
| | - Huiqiang Lou
- a Beijing Advanced Innovation Center for Food Nutrition and Human Health , State Key Laboratory of Agrobiotechnology , MOA Key Laboratory of Soil Microbiology , College of Biological Sciences , China Agricultural University , Beijing 100193 , China
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34
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Szambowska A, Tessmer I, Prus P, Schlott B, Pospiech H, Grosse F. Cdc45-induced loading of human RPA onto single-stranded DNA. Nucleic Acids Res 2017; 45:3217-3230. [PMID: 28100698 PMCID: PMC5389570 DOI: 10.1093/nar/gkw1364] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 01/02/2017] [Indexed: 11/14/2022] Open
Abstract
Cell division cycle protein 45 (Cdc45) is an essential component of the eukaryotic replicative DNA helicase. We found that human Cdc45 forms a complex with the single-stranded DNA (ssDNA) binding protein RPA. Moreover, it actively loads RPA onto nascent ssDNA. Pull-down assays and surface plasmon resonance studies revealed that Cdc45-bound RPA complexed with ssDNA in the 8–10 nucleotide binding mode, but dissociated when RPA covered a 30-mer. Real-time analysis of RPA-ssDNA binding demonstrated that Cdc45 catalytically loaded RPA onto ssDNA. This placement reaction required physical contacts of Cdc45 with the RPA70A subdomain. Our results imply that Cdc45 controlled stabilization of the 8-nt RPA binding mode, the subsequent RPA transition into 30-mer mode and facilitated an ordered binding to ssDNA. We propose that a Cdc45-mediated loading guarantees a seamless deposition of RPA on newly emerging ssDNA at the nascent replication fork.
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Affiliation(s)
- Anna Szambowska
- Research Group Biochemistry, Leibniz Institute on Aging-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Ingrid Tessmer
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Josef Schneider Strasse 2, D-97080 Würzburg, Germany
| | - Piotr Prus
- Biocenter Oulu, P.O. Box 5000, 90014 University of Oulu, Finland
| | - Bernhard Schlott
- Research Group Biochemistry, Leibniz Institute on Aging-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany.,Proteomics Core Facility, Leibniz Institute on Aging-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Helmut Pospiech
- Research Group Biochemistry, Leibniz Institute on Aging-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany.,Faculty of Biochemistry and Molecular Medicine, P.O. Box 5000, 90014 University of Oulu, Finland
| | - Frank Grosse
- Research Group Biochemistry, Leibniz Institute on Aging-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany.,Center for Molecular Biomedicine, Friedrich-Schiller University, Biochemistry Department, Jena, Germany
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35
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Liu X, Dang Y, Matsu-Ura T, He Y, He Q, Hong CI, Liu Y. DNA Replication Is Required for Circadian Clock Function by Regulating Rhythmic Nucleosome Composition. Mol Cell 2017. [PMID: 28648778 DOI: 10.1016/j.molcel.2017.05.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Although the coupling between circadian and cell cycles allows circadian clocks to gate cell division and DNA replication in many organisms, circadian clocks were thought to function independently of cell cycle. Here, we show that DNA replication is required for circadian clock function in Neurospora. Genetic and pharmacological inhibition of DNA replication abolished both overt and molecular rhythmicities by repressing frequency (frq) gene transcription. DNA replication is essential for the rhythmic changes of nucleosome composition at the frq promoter. The FACT complex, known to be involved in histone disassembly/reassembly, is required for clock function and is recruited to the frq promoter in a replication-dependent manner to promote replacement of histone H2A.Z by H2A. Finally, deletion of H2A.Z uncoupled the dependence of the circadian clock on DNA replication. Together, these results establish circadian clock and cell cycle as interdependent coupled oscillators and identify DNA replication as a critical process in the circadian mechanism.
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Affiliation(s)
- Xiao Liu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA
| | - Yunkun Dang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA
| | - Toru Matsu-Ura
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Yubo He
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA; Department of Biochemistry and Cell Biology, McMurtry College, Rice University, Houston, TX 77005, USA
| | - Qun He
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Christian I Hong
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Yi Liu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA.
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36
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Rowlands H, Dhavarasa P, Cheng A, Yankulov K. Forks on the Run: Can the Stalling of DNA Replication Promote Epigenetic Changes? Front Genet 2017; 8:86. [PMID: 28690636 PMCID: PMC5479891 DOI: 10.3389/fgene.2017.00086] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/06/2017] [Indexed: 11/13/2022] Open
Abstract
Built of DNA polymerases and multiple associated factors, the replication fork steadily progresses along the DNA template and faithfully replicates DNA. This model can be found in practically every textbook of genetics, with the more complex situation of chromatinized DNA in eukaryotes often viewed as a variation. However, the replication-coupled disassembly/reassembly of chromatin adds significant complexity to the whole replication process. During the course of eukaryotic DNA replication the forks encounter various conditions and numerous impediments. These include nucleosomes with a variety of post-translational modifications, euchromatin and heterochromatin, differentially methylated DNA, tightly bound proteins, active gene promoters and DNA loops. At such positions the forks slow down or even stall. Dedicated factors stabilize the fork and prevent its rotation or collapse, while other factors resolve the replication block and facilitate the resumption of elongation. The fate of histones during replication stalling and resumption is not well understood. In this review we briefly describe recent advances in our understanding of histone turnover during DNA replication and focus on the possible mechanisms of nucleosome disassembly/reassembly at paused replication forks. We propose that replication pausing provides opportunities for an epigenetic change of the associated locus.
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Affiliation(s)
- Hollie Rowlands
- Department of Molecular and Cellular Biology, University of Guelph, GuelphON, Canada
| | - Piriththiv Dhavarasa
- Department of Molecular and Cellular Biology, University of Guelph, GuelphON, Canada
| | - Ashley Cheng
- Department of Molecular and Cellular Biology, University of Guelph, GuelphON, Canada
| | - Krassimir Yankulov
- Department of Molecular and Cellular Biology, University of Guelph, GuelphON, Canada
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37
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Chi L, Zou Y, Qin L, Ma W, Hao Y, Tang Y, Luo R, Wu Z. TIMELESS contributes to the progression of breast cancer through activation of MYC. Breast Cancer Res 2017; 19:53. [PMID: 28464854 PMCID: PMC5414141 DOI: 10.1186/s13058-017-0838-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/18/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Breast cancer is the most common malignancy and the leading cause of cancer death among women. TIMELESS (TIM), a circadian rhythm regulator, has been recently implicated in the progression of human cancer. However, the role of TIM in the progression of breast cancer has not been well-characterized. METHODS Immunohistochemistry (IHC) staining was used to examine TIM levels in breast cancer specimens. Mammosphere formation analysis and side population analysis were used to examine the effect of TIM on the self-renewal of breast cancer stem cells. A wound healing assay and a Transwell assay were used to determine the role of TIM in breast cancer cell migration and invasion. A soft agar growth assay in vitro and tumorigenicity in vivo were used to determine the role of TIM in tumorigenicity. RESULTS TIM levels in both breast cancer cell lines and tissues were significantly upregulated. Patients with high TIM had poorer prognosis than patients with low TIM. Overexpression of TIM dramatically enhanced, while knockdown of TIM suppressed the self-renewal of cancer stem cells (CSCs), cell invasion and migration abilities of breast cancer cells in vitro. Moreover, overexpression of TIM significantly augmented, while knockdown of TIM reduced the tumorigenicity of breast cancer cells in vivo. Mechanism studies revealed that TIM upregulated the expression and the trans-activity of the well-known oncogene MYC. Inhibition of MYC significantly blocked the effects of TIM on CSC population, cell invasion and anchor-independent cell growth. CONCLUSION TIM plays an important role in promoting breast cancer progression and may represent a novel therapeutic target for breast cancer.
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Affiliation(s)
- Limin Chi
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China
| | - Yujiao Zou
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China
| | - Ling Qin
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China
| | - Weifeng Ma
- Department of Microbiology, School of Public Health, Southern Medical University, Guangzhou, 510515, China
| | - Yanyan Hao
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China
| | - Yao Tang
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China
| | - Rongcheng Luo
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China.
| | - Ziqing Wu
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China. .,Key Laboratory of Molecular Tumor Pathology of Guangdong Province, Southern Medical University, Guangzhou, 510515, China. .,Department of Pathology, School of Basic Medical Science, Southern Medical University, Guangzhou, 510515, China.
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38
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Gadaleta MC, Noguchi E. Regulation of DNA Replication through Natural Impediments in the Eukaryotic Genome. Genes (Basel) 2017; 8:genes8030098. [PMID: 28272375 PMCID: PMC5368702 DOI: 10.3390/genes8030098] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 03/03/2017] [Indexed: 02/07/2023] Open
Abstract
All living organisms need to duplicate their genetic information while protecting it from unwanted mutations, which can lead to genetic disorders and cancer development. Inaccuracies during DNA replication are the major cause of genomic instability, as replication forks are prone to stalling and collapse, resulting in DNA damage. The presence of exogenous DNA damaging agents as well as endogenous difficult-to-replicate DNA regions containing DNA–protein complexes, repetitive DNA, secondary DNA structures, or transcribing RNA polymerases, increases the risk of genomic instability and thus threatens cell survival. Therefore, understanding the cellular mechanisms required to preserve the genetic information during S phase is of paramount importance. In this review, we will discuss our current understanding of how cells cope with these natural impediments in order to prevent DNA damage and genomic instability during DNA replication.
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Affiliation(s)
- Mariana C Gadaleta
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA.
| | - Eishi Noguchi
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA.
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39
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Shen Y, Liu S, Fan J, Jin Y, Tian B, Zheng X, Fu H. Nuclear retention of the lncRNA SNHG1 by doxorubicin attenuates hnRNPC-p53 protein interactions. EMBO Rep 2017; 18:536-548. [PMID: 28264987 DOI: 10.15252/embr.201643139] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 01/26/2017] [Accepted: 02/06/2017] [Indexed: 01/08/2023] Open
Abstract
The protein p53 plays a crucial role in the regulation of cellular responses to diverse stresses. Thus, a major priority in cell biology is to define the mechanisms that regulate p53 activity in response to stresses or maintain it at basal levels under normal conditions. Moreover, further investigation is required to establish whether RNA participates in regulating p53's interaction with other proteins. Here, by conducting systematic experiments, we discovered a p53 interactor-hnRNPC-that directly binds to p53, destabilizes it, and prevents its activation under normal conditions. Upon doxorubicin treatment, the lncRNA SNHG1 is retained in the nucleus through its binding with nucleolin and it competes with p53 for hnRNPC binding, which upregulates p53 levels and promotes p53-dependent apoptosis by impairing hnRNPC regulation of p53 activity. Our results indicate that a balance between lncRNA SNHG1 and hnRNPC regulates p53 activity and p53-dependent apoptosis upon doxorubicin treatment, and further indicate that a change in lncRNA subcellular localization under specific circumstances is biologically significant.
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Affiliation(s)
- Yuan Shen
- Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China.,Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Shanshan Liu
- Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China.,Key Laboratory for Molecular Enzymology and Engineering (The Ministry of Education), College of Life Sciences, Jilin University, Changchun, Jilin, China
| | - Jiao Fan
- Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China.,Institute of Geriatrics, Chinese PLA General Hospital, Beijing, China
| | - Yinghua Jin
- Key Laboratory for Molecular Enzymology and Engineering (The Ministry of Education), College of Life Sciences, Jilin University, Changchun, Jilin, China
| | - Baolei Tian
- Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Xiaofei Zheng
- Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Hanjiang Fu
- Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
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40
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The Causes and Consequences of Topological Stress during DNA Replication. Genes (Basel) 2016; 7:genes7120134. [PMID: 28009828 PMCID: PMC5192510 DOI: 10.3390/genes7120134] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/11/2016] [Accepted: 12/14/2016] [Indexed: 01/08/2023] Open
Abstract
The faithful replication of sister chromatids is essential for genomic integrity in every cell division. The replication machinery must overcome numerous difficulties in every round of replication, including DNA topological stress. Topological stress arises due to the double-stranded helical nature of DNA. When the strands are pulled apart for replication to occur, the intertwining of the double helix must also be resolved or topological stress will arise. This intrinsic problem is exacerbated by specific chromosomal contexts encountered during DNA replication. The convergence of two replicons during termination, the presence of stable protein-DNA complexes and active transcription can all lead to topological stresses being imposed upon DNA replication. Here we describe how replication forks respond to topological stress by replication fork rotation and fork reversal. We also discuss the genomic contexts where topological stress is likely to occur in eukaryotes, focusing on the contribution of transcription. Finally, we describe how topological stress, and the ways forks respond to it, may contribute to genomic instability in cells.
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41
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Phosphorylation of CMG helicase and Tof1 is required for programmed fork arrest. Proc Natl Acad Sci U S A 2016; 113:E3639-48. [PMID: 27298353 DOI: 10.1073/pnas.1607552113] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Several important physiological transactions, including control of replicative life span (RLS), prevention of collision between replication and transcription, and cellular differentiation, require programmed replication fork arrest (PFA). However, a general mechanism of PFA has remained elusive. We previously showed that the Tof1-Csm3 fork protection complex is essential for PFA by antagonizing the Rrm3 helicase that displaces nonhistone protein barriers that impede fork progression. Here we show that mutations of Dbf4-dependent kinase (DDK) of Saccharomyces cerevisiae, but not other DNA replication factors, greatly reduced PFA at replication fork barriers in the spacer regions of the ribosomal DNA array. A key target of DDK is the mini chromosome maintenance (Mcm) 2-7 complex, which is known to require phosphorylation by DDK to form an active CMG [Cdc45 (cell division cycle gene 45), Mcm2-7, GINS (Go, Ichi, Ni, and San)] helicase. In vivo experiments showed that mutational inactivation of DDK caused release of Tof1 from the chromatin fractions. In vitro binding experiments confirmed that CMG and/or Mcm2-7 had to be phosphorylated for binding to phospho-Tof1-Csm3 but not to its dephosphorylated form. Suppressor mutations that bypass the requirement for Mcm2-7 phosphorylation by DDK restored PFA in the absence of the kinase. Retention of Tof1 in the chromatin fraction and PFA in vivo was promoted by the suppressor mcm5-bob1, which bypassed DDK requirement, indicating that under this condition a kinase other than DDK catalyzed the phosphorylation of Tof1. We propose that phosphorylation regulates the recruitment and retention of Tof1-Csm3 by the replisome and that this complex antagonizes the Rrm3 helicase, thereby promoting PFA, by preserving the integrity of the Fob1-Ter complex.
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42
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McGarry E, Gaboriau D, Rainey MD, Restuccia U, Bachi A, Santocanale C. The Deubiquitinase USP9X Maintains DNA Replication Fork Stability and DNA Damage Checkpoint Responses by Regulating CLASPIN during S-Phase. Cancer Res 2016; 76:2384-93. [PMID: 26921344 DOI: 10.1158/0008-5472.can-15-2890] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 02/15/2016] [Indexed: 11/16/2022]
Abstract
Coordination of the multiple processes underlying DNA replication is key for maintaining genome stability and preventing tumorigenesis. CLASPIN, a critical player in replication fork stabilization and checkpoint responses, must be tightly regulated during the cell cycle to prevent the accumulation of DNA damage. In this study, we used a quantitative proteomics approach and identified USP9X as a novel CLASPIN-interacting protein. USP9X is a deubiquitinase involved in multiple signaling and survival pathways whose tumor suppressor or oncogenic activity is highly context dependent. We found that USP9X regulated the expression and stability of CLASPIN in an S-phase-specific manner. USP9X depletion profoundly impairs the progression of DNA replication forks, causing unscheduled termination events with a frequency similar to CLASPIN depletion, resulting in excessive endogenous DNA damage. Importantly, restoration of CLASPIN expression in USP9X-depleted cells partially suppressed the accumulation of DNA damage. Furthermore, USP9X depletion compromised CHK1 activation in response to hydroxyurea and UV, thus promoting hypersensitivity to drug-induced replication stress. Taken together, our results reveal a novel role for USP9X in the maintenance of genomic stability during DNA replication and provide potential mechanistic insights into its tumor suppressor role in certain malignancies. Cancer Res; 76(8); 2384-93. ©2016 AACR.
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Affiliation(s)
- Edel McGarry
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - David Gaboriau
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Michael D Rainey
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | | | - Angela Bachi
- IFOM-FIRC Institute of Molecular Oncology, Milan, Italy
| | - Corrado Santocanale
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
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43
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A Timeless Link Between Circadian Patterns and Disease. Trends Mol Med 2016; 22:68-81. [DOI: 10.1016/j.molmed.2015.11.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 11/16/2015] [Accepted: 11/18/2015] [Indexed: 02/06/2023]
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44
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Calì F, Bharti SK, Di Perna R, Brosh RM, Pisani FM. Tim/Timeless, a member of the replication fork protection complex, operates with the Warsaw breakage syndrome DNA helicase DDX11 in the same fork recovery pathway. Nucleic Acids Res 2015; 44:705-17. [PMID: 26503245 PMCID: PMC4737141 DOI: 10.1093/nar/gkv1112] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 10/13/2015] [Indexed: 11/15/2022] Open
Abstract
We present evidence that Tim establishes a physical and functional interaction with DDX11, a super-family 2 iron-sulfur cluster DNA helicase genetically linked to the chromosomal instability disorder Warsaw breakage syndrome. Tim stimulates DDX11 unwinding activity on forked DNA substrates up to 10-fold and on bimolecular anti-parallel G-quadruplex DNA structures and three-stranded D-loop approximately 4–5-fold. Electrophoretic mobility shift assays revealed that Tim enhances DDX11 binding to DNA, suggesting that the observed stimulation derives from an improved ability of DDX11 to interact with the nucleic acid substrate. Surface plasmon resonance measurements indicate that DDX11 directly interacts with Tim. DNA fiber track assays with HeLa cells exposed to hydroxyurea demonstrated that Tim or DDX11 depletion significantly reduced replication fork progression compared to control cells; whereas no additive effect was observed by co-depletion of both proteins. Moreover, Tim and DDX11 are epistatic in promoting efficient resumption of stalled DNA replication forks in hydroxyurea-treated cells. This is consistent with the finding that association of the two endogenous proteins in the cell extract chromatin fraction is considerably increased following hydroxyurea exposure. Overall, our studies provide evidence that Tim and DDX11 physically and functionally interact and act in concert to preserve replication fork progression in perturbed conditions.
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Affiliation(s)
- Federica Calì
- Istituto di Biochimica delle Proteine, Consiglio Nazionale delle Ricerche, Via Pietro Castellino, 111. 80131 - Napoli, Italy
| | - Sanjay Kumar Bharti
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, 251 Bayview Blvd, Baltimore, MD 21224 USA
| | - Roberta Di Perna
- Istituto di Biochimica delle Proteine, Consiglio Nazionale delle Ricerche, Via Pietro Castellino, 111. 80131 - Napoli, Italy
| | - Robert M Brosh
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, 251 Bayview Blvd, Baltimore, MD 21224 USA
| | - Francesca M Pisani
- Istituto di Biochimica delle Proteine, Consiglio Nazionale delle Ricerche, Via Pietro Castellino, 111. 80131 - Napoli, Italy
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45
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Xie S, Mortusewicz O, Ma HT, Herr P, Poon RYC, Poon RRY, Helleday T, Qian C. Timeless Interacts with PARP-1 to Promote Homologous Recombination Repair. Mol Cell 2015; 60:163-76. [PMID: 26344098 DOI: 10.1016/j.molcel.2015.07.031] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 05/01/2015] [Accepted: 07/29/2015] [Indexed: 12/21/2022]
Abstract
Human Timeless helps stabilize replication forks during normal DNA replication and plays a critical role in activation of the S phase checkpoint and proper establishment of sister chromatid cohesion. However, it remains elusive whether Timeless is involved in the repair of damaged DNA. Here, we identify that Timeless physically interacts with PARP-1 independent of poly(ADP-ribosyl)ation. We present high-resolution crystal structures of Timeless PAB (PARP-1-binding domain) in free form and in complex with PARP-1 catalytic domain. Interestingly, Timeless PAB domain specifically recognizes PARP-1, but not PARP-2 or PARP-3. Timeless-PARP-1 interaction does not interfere with PARP-1 enzymatic activity. We demonstrate that rapid and transient accumulation of Timeless at laser-induced DNA damage sites requires PARP-1, but not poly(ADP-ribosyl)ation and that Timeless is co-trapped with PARP-1 at DNA lesions upon PARP inhibition. Furthermore, we show that Timeless and PARP-1 interaction is required for efficient homologous recombination repair.
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Affiliation(s)
- Si Xie
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong
| | - Oliver Mortusewicz
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Hoi Tang Ma
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong
| | - Patrick Herr
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Randy Y C Poon
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong
| | - Randy R Y Poon
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong
| | - Thomas Helleday
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden.
| | - Chengmin Qian
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong.
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Schalbetter SA, Mansoubi S, Chambers AL, Downs JA, Baxter J. Fork rotation and DNA precatenation are restricted during DNA replication to prevent chromosomal instability. Proc Natl Acad Sci U S A 2015; 112:E4565-70. [PMID: 26240319 PMCID: PMC4547287 DOI: 10.1073/pnas.1505356112] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Faithful genome duplication and inheritance require the complete resolution of all intertwines within the parental DNA duplex. This is achieved by topoisomerase action ahead of the replication fork or by fork rotation and subsequent resolution of the DNA precatenation formed. Although fork rotation predominates at replication termination, in vitro studies have suggested that it also occurs frequently during elongation. However, the factors that influence fork rotation and how rotation and precatenation may influence other replication-associated processes are unknown. Here we analyze the causes and consequences of fork rotation in budding yeast. We find that fork rotation and precatenation preferentially occur in contexts that inhibit topoisomerase action ahead of the fork, including stable protein-DNA fragile sites and termination. However, generally, fork rotation and precatenation are actively inhibited by Timeless/Tof1 and Tipin/Csm3. In the absence of Tof1/Timeless, excessive fork rotation and precatenation cause extensive DNA damage following DNA replication. With Tof1, damage related to precatenation is focused on the fragile protein-DNA sites where fork rotation is induced. We conclude that although fork rotation and precatenation facilitate unwinding in hard-to-replicate contexts, they intrinsically disrupt normal chromosome duplication and are therefore restricted by Timeless/Tipin.
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Affiliation(s)
- Stephanie A Schalbetter
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton, East Sussex BN1 9RQ, United Kingdom
| | - Sahar Mansoubi
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton, East Sussex BN1 9RQ, United Kingdom
| | - Anna L Chambers
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton, East Sussex BN1 9RQ, United Kingdom; School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Jessica A Downs
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton, East Sussex BN1 9RQ, United Kingdom
| | - Jonathan Baxter
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton, East Sussex BN1 9RQ, United Kingdom;
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Mcm2-7 Is an Active Player in the DNA Replication Checkpoint Signaling Cascade via Proposed Modulation of Its DNA Gate. Mol Cell Biol 2015; 35:2131-43. [PMID: 25870112 DOI: 10.1128/mcb.01357-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 04/05/2015] [Indexed: 01/01/2023] Open
Abstract
The DNA replication checkpoint (DRC) monitors and responds to stalled replication forks to prevent genomic instability. How core replication factors integrate into this phosphorylation cascade is incompletely understood. Here, through analysis of a unique mcm allele targeting a specific ATPase active site (mcm2DENQ), we show that the Mcm2-7 replicative helicase has a novel DRC function as part of the signal transduction cascade. This allele exhibits normal downstream mediator (Mrc1) phosphorylation, implying DRC sensor kinase activation. However, the mutant also exhibits defective effector kinase (Rad53) activation and classic DRC phenotypes. Our previous in vitro analysis showed that the mcm2DENQ mutation prevents a specific conformational change in the Mcm2-7 hexamer. We infer that this conformational change is required for its DRC role and propose that it allosterically facilitates Rad53 activation to ensure a replication-specific checkpoint response.
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48
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The Human RNA Polymerase I Transcription Terminator Complex Acts as a Replication Fork Barrier That Coordinates the Progress of Replication with rRNA Transcription Activity. Mol Cell Biol 2015; 35:1871-81. [PMID: 25776556 DOI: 10.1128/mcb.01521-14] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 03/09/2015] [Indexed: 01/28/2023] Open
Abstract
In S phase, the replication and transcription of genomic DNA need to accommodate each other, otherwise their machineries collide, with chromosomal instability as a possible consequence. Here, we characterized the human replication fork barrier (RFB) that is present downstream from the 47S pre-rRNA gene (ribosomal DNA [rDNA]). We found that the most proximal transcription terminator, Sal box T1, acts as a polar RFB, while the other, Sal box T4/T5, arrests replication forks bidirectionally. The fork-arresting activity at these sites depends on polymerase I (Pol I) transcription termination factor 1 (TTF-1) and a replisome component, TIMELESS (TIM). We also found that the RFB activity was linked to rDNA copies with hypomethylated CpG and coincided with the time that actively transcribed rRNA genes are replicated. Failed fork arrest at RFB sites led to a slowdown of fork progression moving in the opposite direction to rRNA transcription. Chemical inhibition of transcription counteracted this deceleration of forks, indicating that rRNA transcription impedes replication in the absence of RFB activity. Thus, our results reveal a role of RFB for coordinating the progression of replication and transcription activity in highly transcribed rRNA genes.
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Ganai RA, Osterman P, Johansson E. Yeast DNA polymerase ϵ catalytic core and holoenzyme have comparable catalytic rates. J Biol Chem 2014; 290:3825-35. [PMID: 25538242 DOI: 10.1074/jbc.m114.615278] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The holoenzyme of yeast DNA polymerase ϵ (Pol ϵ) consists of four subunits: Pol2, Dpb2, Dpb3, and Dpb4. A protease-sensitive site results in an N-terminal proteolytic fragment of Pol2, called Pol2core, that consists of the catalytic core of Pol ϵ and retains both polymerase and exonuclease activities. Pre-steady-state kinetics showed that the exonuclease rates on single-stranded, double-stranded, and mismatched DNA were comparable between Pol ϵ and Pol2core. Single-turnover pre-steady-state kinetics also showed that the kpol of Pol ϵ and Pol2core were comparable when preloading the polymerase onto the primer-template before adding Mg(2+) and dTTP. However, a global fit of the data over six sequential nucleotide incorporations revealed that the overall polymerization rate and processivity were higher for Pol ϵ than for Pol2core. The largest difference between Pol ϵ and Pol2core was observed when challenged for the formation of a ternary complex and incorporation of the first nucleotide. Pol ϵ needed less than 1 s to incorporate a nucleotide, but several seconds passed before Pol2core incorporated detectable levels of the first nucleotide. We conclude that the accessory subunits and the C terminus of Pol2 do not influence the catalytic rate of Pol ϵ but facilitate the loading and incorporation of the first nucleotide by Pol ϵ.
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Affiliation(s)
- Rais A Ganai
- From the Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden
| | - Pia Osterman
- From the Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden
| | - Erik Johansson
- From the Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden
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50
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Witosch J, Wolf E, Mizuno N. Architecture and ssDNA interaction of the Timeless-Tipin-RPA complex. Nucleic Acids Res 2014; 42:12912-27. [PMID: 25348395 PMCID: PMC4227788 DOI: 10.1093/nar/gku960] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The Timeless-Tipin (Tim-Tipin) complex, also referred to as the fork protection complex, is involved in coordination of DNA replication. Tim-Tipin is suggested to be recruited to replication forks via Replication Protein A (RPA) but details of the interaction are unknown. Here, using cryo-EM and biochemical methods, we characterized complex formation of Tim-Tipin, RPA and single-stranded DNA (ssDNA). Tim-Tipin and RPA form a 258 kDa complex with a 1:1:1 stoichiometry. The cryo-EM 3D reconstruction revealed a globular architecture of the Tim-Tipin-RPA complex with a ring-like and a U-shaped domain covered by a RPA lid. Interestingly, RPA in the complex adopts a horse shoe-like shape resembling its conformation in the presence of long ssDNA (>30 nucleotides). Furthermore, the recruitment of the Tim-Tipin-RPA complex to ssDNA is modulated by the RPA conformation and requires RPA to be in the more compact 30 nt ssDNA binding mode. The dynamic formation and disruption of the Tim-Tipin-RPA-ssDNA complex implicates the RPA-based recruitment of Tim-Tipin to the replication fork.
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Affiliation(s)
- Justine Witosch
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Eva Wolf
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany Department of Physiological Chemistry and Center For Integrated Protein Science Munich (CIPSM), Butenandt Institute, Ludwig Maximilians University of Munich, Butenandtstrasse 5, 81377 Munich, Germany Institut für allgemeine Botanik, Johannes Gutenberg-University, Johannes-von-Müller-Weg 6, 55128 Mainz, Germany and Institute of Molecular Biology (IMB), Mainz, Germany
| | - Naoko Mizuno
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
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