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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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52
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Göder A, Quinlan A, Rainey MD, Bennett D, Shamavu D, Corso J, Santocanale C. PTBP1 enforces ATR-CHK1 signaling determining the potency of CDC7 inhibitors. iScience 2023; 26:106951. [PMID: 37378325 PMCID: PMC10291475 DOI: 10.1016/j.isci.2023.106951] [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: 01/24/2023] [Revised: 04/27/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
CDC7 kinase is crucial for DNA replication initiation and fork processing. CDC7 inhibition mildly activates the ATR pathway, which further limits origin firing; however, to date the relationship between CDC7 and ATR remains controversial. We show that CDC7 and ATR inhibitors are either synergistic or antagonistic depending on the degree of inhibition of each individual kinase. We find that Polypyrimidine Tract Binding Protein 1 (PTBP1) is important for ATR activity in response to CDC7 inhibition and genotoxic agents. Compromised PTBP1 expression makes cells defective in RPA recruitment, genomically unstable, and resistant to CDC7 inhibitors. PTBP1 deficiency affects the expression and splicing of many genes indicating a multifactorial impact on drug response. We find that an exon skipping event in RAD51AP1 contributes to checkpoint deficiency in PTBP1-deficient cells. These results identify PTBP1 as a key factor in replication stress response and define how ATR activity modulates the activity of CDC7 inhibitors.
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Affiliation(s)
- Anja Göder
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
| | - Aisling Quinlan
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
| | - Michael D. Rainey
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
| | - Declan Bennett
- School of Mathematical & Statistical Sciences, University of Galway, Galway H91TK33, Ireland
| | - Daniel Shamavu
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
| | - Jacqueline Corso
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
| | - Corrado Santocanale
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
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53
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Zhang A, Friedman LJ, Gelles J, Bell SP. Changing protein-DNA interactions promote ORC binding site exchange during replication origin licensing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.16.545300. [PMID: 37398123 PMCID: PMC10312730 DOI: 10.1101/2023.06.16.545300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
During origin licensing, the eukaryotic replicative helicase Mcm2-7 forms head-to-head double hexamers to prime origins for bidirectional replication. Recent single-molecule and structural studies revealed that one molecule of the helicase loader ORC can sequentially load two Mcm2-7 hexamers to ensure proper head-to-head helicase alignment. To perform this task, ORC must release from its initial high-affinity DNA binding site and "flip" to bind a weaker, inverted DNA site. However, the mechanism of this binding-site switch remains unclear. In this study, we used single-molecule Förster resonance energy transfer (sm-FRET) to study the changing interactions between DNA and ORC or Mcm2-7. We found that the loss of DNA bending that occurs during DNA deposition into the Mcm2-7 central channel increases the rate of ORC dissociation from DNA. Further studies revealed temporally-controlled DNA sliding of helicase-loading intermediates, and that the first sliding complex includes ORC, Mcm2-7, and Cdt1. We demonstrate that sequential events of DNA unbending, Cdc6 release, and sliding lead to a stepwise decrease in ORC stability on DNA, facilitating ORC dissociation from its strong binding site during site switching. In addition, the controlled sliding we observed provides insight into how ORC accesses secondary DNA binding sites at different locations relative to the initial binding site. Our study highlights the importance of dynamic protein-DNA interactions in the loading of two oppositely-oriented Mcm2-7 helicases to ensure bidirectional DNA replication. Significance Statement Bidirectional DNA replication, in which two replication forks travel in opposite directions from each origin of replication, is required for complete genome duplication. To prepare for this event, two copies of the Mcm2-7 replicative helicase are loaded at each origin in opposite orientations. Using single-molecule assays, we studied the sequence of changing protein-DNA interactions involved in this process. These stepwise changes gradually reduce the DNA-binding strength of ORC, the primary DNA binding protein involved in this event. This reduced affinity promotes ORC dissociation and rebinding in the opposite orientation on the DNA, facilitating the sequential assembly of two Mcm2-7 molecules in opposite orientations. Our findings identify a coordinated series of events that drive proper DNA replication initiation.
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Affiliation(s)
- Annie Zhang
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Larry J. Friedman
- Department of Biochemistry, Brandeis University, Waltham, MA 02454, USA
| | - Jeff Gelles
- Department of Biochemistry, Brandeis University, Waltham, MA 02454, USA
| | - Stephen P Bell
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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54
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Radford HM, Toft CJ, Sorenson AE, Schaeffer PM. Inhibition of Replication Fork Formation and Progression: Targeting the Replication Initiation and Primosomal Proteins. Int J Mol Sci 2023; 24:ijms24108802. [PMID: 37240152 DOI: 10.3390/ijms24108802] [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: 03/31/2023] [Revised: 05/02/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Over 1.2 million deaths are attributed to multi-drug-resistant (MDR) bacteria each year. Persistence of MDR bacteria is primarily due to the molecular mechanisms that permit fast replication and rapid evolution. As many pathogens continue to build resistance genes, current antibiotic treatments are being rendered useless and the pool of reliable treatments for many MDR-associated diseases is thus shrinking at an alarming rate. In the development of novel antibiotics, DNA replication is still a largely underexplored target. This review summarises critical literature and synthesises our current understanding of DNA replication initiation in bacteria with a particular focus on the utility and applicability of essential initiation proteins as emerging drug targets. A critical evaluation of the specific methods available to examine and screen the most promising replication initiation proteins is provided.
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Affiliation(s)
- Holly M Radford
- Molecular and Cell Biology, College of Public Health, Medical and Veterinary Sciences, James Cook University, Douglas, QLD 4811, Australia
| | - Casey J Toft
- Molecular and Cell Biology, College of Public Health, Medical and Veterinary Sciences, James Cook University, Douglas, QLD 4811, Australia
| | - Alanna E Sorenson
- Molecular and Cell Biology, College of Public Health, Medical and Veterinary Sciences, James Cook University, Douglas, QLD 4811, Australia
| | - Patrick M Schaeffer
- Molecular and Cell Biology, College of Public Health, Medical and Veterinary Sciences, James Cook University, Douglas, QLD 4811, Australia
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55
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Nasheuer HP, Onwubiko NO. Lagging Strand Initiation Processes in DNA Replication of Eukaryotes-Strings of Highly Coordinated Reactions Governed by Multiprotein Complexes. Genes (Basel) 2023; 14:genes14051012. [PMID: 37239371 DOI: 10.3390/genes14051012] [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: 04/06/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
In their influential reviews, Hanahan and Weinberg coined the term 'Hallmarks of Cancer' and described genome instability as a property of cells enabling cancer development. Accurate DNA replication of genomes is central to diminishing genome instability. Here, the understanding of the initiation of DNA synthesis in origins of DNA replication to start leading strand synthesis and the initiation of Okazaki fragment on the lagging strand are crucial to control genome instability. Recent findings have provided new insights into the mechanism of the remodelling of the prime initiation enzyme, DNA polymerase α-primase (Pol-prim), during primer synthesis, how the enzyme complex achieves lagging strand synthesis, and how it is linked to replication forks to achieve optimal initiation of Okazaki fragments. Moreover, the central roles of RNA primer synthesis by Pol-prim in multiple genome stability pathways such as replication fork restart and protection of DNA against degradation by exonucleases during double-strand break repair are discussed.
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Affiliation(s)
- Heinz Peter Nasheuer
- Centre for Chromosome Biology, Arts & Science Building, Main Concourse, School of Biological and Chemical Sciences, Biochemistry, University of Galway, Distillery Road, H91 TK33 Galway, Ireland
| | - Nichodemus O Onwubiko
- Centre for Chromosome Biology, Arts & Science Building, Main Concourse, School of Biological and Chemical Sciences, Biochemistry, University of Galway, Distillery Road, H91 TK33 Galway, Ireland
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56
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Liu W, Saito Y, Jackson J, Bhowmick R, Kanemaki MT, Vindigni A, Cortez D. RAD51 bypasses the CMG helicase to promote replication fork reversal. Science 2023; 380:382-387. [PMID: 37104614 PMCID: PMC10302453 DOI: 10.1126/science.add7328] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 03/25/2023] [Indexed: 04/29/2023]
Abstract
Replication fork reversal safeguards genome integrity as a replication stress response. DNA translocases and the RAD51 recombinase catalyze reversal. However, it remains unknown why RAD51 is required and what happens to the replication machinery during reversal. We find that RAD51 uses its strand exchange activity to circumvent the replicative helicase, which remains bound to the stalled fork. RAD51 is not required for fork reversal if the helicase is unloaded. Thus, we propose that RAD51 creates a parental DNA duplex behind the helicase that is used as a substrate by the DNA translocases for branch migration to create a reversed fork structure. Our data explain how fork reversal happens while maintaining the helicase in a position poised to restart DNA synthesis and complete genome duplication.
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Affiliation(s)
- Wenpeng Liu
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37237 USA
| | - Yuichiro Saito
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Yata 1111, Mishima, Shizuoka, 411-8540, Japan
| | - Jessica Jackson
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Rahul Bhowmick
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37237 USA
| | - Masato T. Kanemaki
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Yata 1111, Mishima, Shizuoka, 411-8540, Japan
- Department of Biological Science, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Alessandro Vindigni
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - David Cortez
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37237 USA
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57
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Brison O, Gnan S, Azar D, Koundrioukoff S, Melendez-Garcia R, Kim SJ, Schmidt M, El-Hilali S, Jaszczyszyn Y, Lachages AM, Thermes C, Chen CL, Debatisse M. Mistimed origin licensing and activation stabilize common fragile sites under tight DNA-replication checkpoint activation. Nat Struct Mol Biol 2023; 30:539-550. [PMID: 37024657 DOI: 10.1038/s41594-023-00949-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 02/28/2023] [Indexed: 04/08/2023]
Abstract
Genome integrity requires replication to be completed before chromosome segregation. The DNA-replication checkpoint (DRC) contributes to this coordination by inhibiting CDK1, which delays mitotic onset. Under-replication of common fragile sites (CFSs), however, escapes surveillance, resulting in mitotic chromosome breaks. Here we asked whether loose DRC activation induced by modest stresses commonly used to destabilize CFSs could explain this leakage. We found that tightening DRC activation or CDK1 inhibition stabilizes CFSs in human cells. Repli-Seq and molecular combing analyses showed a burst of replication initiations implemented in mid S-phase across a subset of late-replicating sequences, including CFSs, while the bulk genome was unaffected. CFS rescue and extra-initiations required CDC6 and CDT1 availability in S-phase, implying that CDK1 inhibition permits mistimed origin licensing and firing. In addition to delaying mitotic onset, tight DRC activation therefore supports replication completion of late origin-poor domains at risk of under-replication, two complementary roles preserving genome stability.
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Affiliation(s)
- Olivier Brison
- CNRS UMR 9019, Gustave Roussy Institute, Villejuif, France
- Paris-Saclay University, Gif-sur-Yvette, France
| | - Stefano Gnan
- Curie Institute, PSL Research University, CNRS UMR 3244, Paris, France
- Sorbonne University, Paris, France
| | - Dana Azar
- Curie Institute, PSL Research University, CNRS UMR 3244, Paris, France
- Sorbonne University, Paris, France
- Laboratoire Biodiversité et Génomique Fonctionnelle, Faculté des Sciences, Université Saint-Joseph, Beirut, Lebanon
| | - Stéphane Koundrioukoff
- CNRS UMR 9019, Gustave Roussy Institute, Villejuif, France
- Sorbonne University, Paris, France
| | - Rodrigo Melendez-Garcia
- CNRS UMR 9019, Gustave Roussy Institute, Villejuif, France
- Paris-Saclay University, Gif-sur-Yvette, France
| | - Su-Jung Kim
- CNRS UMR 9019, Gustave Roussy Institute, Villejuif, France
- Paris-Saclay University, Gif-sur-Yvette, France
| | - Mélanie Schmidt
- CNRS UMR 9019, Gustave Roussy Institute, Villejuif, France
- Paris-Saclay University, Gif-sur-Yvette, France
| | - Sami El-Hilali
- Curie Institute, PSL Research University, CNRS UMR 3244, Paris, France
- Sorbonne University, Paris, France
- Villefranche sur mer Developmental Biology Laboratory, CNRS UMR7009, Villefranche-sur-Mer, France
| | - Yan Jaszczyszyn
- Paris-Saclay University, Gif-sur-Yvette, France
- Institute for Integrative Biology of the Cell (I2BC), UMR 9198CNRS, CEA, Paris-Sud University, Gif-sur-Yvette, France
| | - Anne-Marie Lachages
- Curie Institute, PSL Research University, CNRS UMR 3244, Paris, France
- UTCBS, CNRS UMR 8258/ INSERM U 1267, Sorbonne-Paris-Cité University, Paris, France
| | - Claude Thermes
- Paris-Saclay University, Gif-sur-Yvette, France
- Institute for Integrative Biology of the Cell (I2BC), UMR 9198CNRS, CEA, Paris-Sud University, Gif-sur-Yvette, France
| | - Chun-Long Chen
- Curie Institute, PSL Research University, CNRS UMR 3244, Paris, France
- Sorbonne University, Paris, France
| | - Michelle Debatisse
- CNRS UMR 9019, Gustave Roussy Institute, Villejuif, France.
- Sorbonne University, Paris, France.
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58
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Kwon J, Lee D, Lee SA. BAP1 as a guardian of genome stability: implications in human cancer. Exp Mol Med 2023; 55:745-754. [PMID: 37009801 PMCID: PMC10167335 DOI: 10.1038/s12276-023-00979-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/02/2023] [Accepted: 01/27/2023] [Indexed: 04/04/2023] Open
Abstract
BAP1 is a ubiquitin C-terminal hydrolase domain-containing deubiquitinase with a wide array of biological activities. Studies in which advanced sequencing technologies were used have uncovered a link between BAP1 and human cancer. Somatic and germline mutations of the BAP1 gene have been identified in multiple human cancers, with a particularly high frequency in mesothelioma, uveal melanoma and clear cell renal cell carcinoma. BAP1 cancer syndrome highlights that all carriers of inherited BAP1-inactivating mutations develop at least one and often multiple cancers with high penetrance during their lifetime. These findings, together with substantial evidence indicating the involvement of BAP1 in many cancer-related biological activities, strongly suggest that BAP1 functions as a tumor suppressor. Nonetheless, the mechanisms that account for the tumor suppressor function of BAP1 have only begun to be elucidated. Recently, the roles of BAP1 in genome stability and apoptosis have drawn considerable attention, and they are compelling candidates for key mechanistic factors. In this review, we focus on genome stability and summarize the details of the cellular and molecular functions of BAP1 in DNA repair and replication, which are crucial for genome integrity, and discuss the implications for BAP1-associated cancer and relevant therapeutic strategies. We also highlight some unresolved issues and potential future research directions.
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Affiliation(s)
- Jongbum Kwon
- Department of Life Science, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul, 03760, Korea.
| | - Daye Lee
- Department of Life Science, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul, 03760, Korea
| | - Shin-Ai Lee
- Department of Life Science, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul, 03760, Korea
- Laboratory of Genitourinary Cancer Pathogenesis, Center for Cancer Research, National Cancer Institute, Building 37, Room 1068, Bethesda, MD, 20892-4263, USA
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59
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Vouzas AE, Gilbert DM. Replication timing and transcriptional control: beyond cause and effect - part IV. Curr Opin Genet Dev 2023; 79:102031. [PMID: 36905782 PMCID: PMC10035587 DOI: 10.1016/j.gde.2023.102031] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/07/2023] [Accepted: 02/11/2023] [Indexed: 03/11/2023]
Abstract
Decades of work on the spatiotemporal organization of mammalian DNA replication timing (RT) continues to unveil novel correlations with aspects of transcription and chromatin organization but, until recently, mechanisms regulating RT and the biological significance of the RT program had been indistinct. We now know that the RT program is both influenced by and necessary to maintain chromatin structure, forming an epigenetic positive feedback loop. Moreover, the discovery of specific cis-acting elements regulating mammalian RT at both the domain and the whole-chromosome level has revealed multiple cell-type-specific and developmentally regulated mechanisms of RT control. We review recent evidence for diverse mechanisms employed by different cell types to regulate their RT programs and the biological significance of RT regulation during development.
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Affiliation(s)
- Athanasios E Vouzas
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA
| | - David M Gilbert
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, San Diego, CA 92121, USA.
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60
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Weiβ M, Chanou A, Schauer T, Tvardovskiy A, Meiser S, König AC, Schmidt T, Kruse E, Ummethum H, Trauner M, Werner M, Lalonde M, Hauck SM, Scialdone A, Hamperl S. Single-copy locus proteomics of early- and late-firing DNA replication origins identifies a role of Ask1/DASH complex in replication timing control. Cell Rep 2023; 42:112045. [PMID: 36701236 PMCID: PMC9989823 DOI: 10.1016/j.celrep.2023.112045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 11/28/2022] [Accepted: 01/13/2023] [Indexed: 01/27/2023] Open
Abstract
The chromatin environment at origins of replication is thought to influence DNA replication initiation in eukaryotic genomes. However, it remains unclear how and which chromatin features control the firing of early-efficient (EE) or late-inefficient (LI) origins. Here, we use site-specific recombination and single-locus chromatin isolation to purify EE and LI replication origins in Saccharomyces cerevisiae. Using mass spectrometry, we define the protein composition of native chromatin regions surrounding the EE and LI replication start sites. In addition to known origin interactors, we find the microtubule-binding Ask1/DASH complex as an origin-regulating factor. Strikingly, tethering of Ask1 to individual origin sites advances replication timing (RT) of the targeted chromosomal domain. Targeted degradation of Ask1 globally changes RT of a subset of origins, which can be reproduced by inhibiting microtubule dynamics. Thus, our findings mechanistically connect RT and chromosomal organization via Ask1/DASH with the microtubule cytoskeleton.
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Affiliation(s)
- Matthias Weiβ
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany
| | - Anna Chanou
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany
| | - Tamas Schauer
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany
| | - Andrey Tvardovskiy
- Institute of Functional Epigenetics, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Stefan Meiser
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany; Institute of Functional Epigenetics, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany; Institute of Computational Biology, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Ann-Christine König
- Metabolomics and Proteomics Core, Helmholtz Zentrum München, German Center for Environmental Health, Heidemannstrasse 1, 80939 München, Germany
| | - Tobias Schmidt
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany
| | - Elisabeth Kruse
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany
| | - Henning Ummethum
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany
| | - Manuel Trauner
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany
| | - Marcel Werner
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany
| | - Maxime Lalonde
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany
| | - Stefanie M Hauck
- Metabolomics and Proteomics Core, Helmholtz Zentrum München, German Center for Environmental Health, Heidemannstrasse 1, 80939 München, Germany
| | - Antonio Scialdone
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany; Institute of Functional Epigenetics, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany; Institute of Computational Biology, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Stephan Hamperl
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany.
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61
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Minamino M, Bouchoux C, Canal B, Diffley JFX, Uhlmann F. A replication fork determinant for the establishment of sister chromatid cohesion. Cell 2023; 186:837-849.e11. [PMID: 36693376 DOI: 10.1016/j.cell.2022.12.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 11/08/2022] [Accepted: 12/22/2022] [Indexed: 01/24/2023]
Abstract
Concomitant with DNA replication, the chromosomal cohesin complex establishes cohesion between newly replicated sister chromatids. Cohesion establishment requires acetylation of conserved cohesin lysine residues by Eco1 acetyltransferase. Here, we explore how cohesin acetylation is linked to DNA replication. Biochemical reconstitution of replication-coupled cohesin acetylation reveals that transient DNA structures, which form during DNA replication, control the acetylation reaction. As polymerases complete lagging strand replication, strand displacement synthesis produces DNA flaps that are trimmed to result in nicked double-stranded DNA. Both flaps and nicks stimulate cohesin acetylation, while subsequent nick ligation to complete Okazaki fragment maturation terminates the acetylation reaction. A flapped or nicked DNA substrate constitutes a transient molecular clue that directs cohesin acetylation to a window behind the replication fork, next to where cohesin likely entraps both sister chromatids. Our results provide an explanation for how DNA replication is linked to sister chromatid cohesion establishment.
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Affiliation(s)
- Masashi Minamino
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Céline Bouchoux
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Berta Canal
- Chromosome Replication Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - John F X Diffley
- Chromosome Replication Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK.
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Hu Y, Stillman B. Origins of DNA replication in eukaryotes. Mol Cell 2023; 83:352-372. [PMID: 36640769 PMCID: PMC9898300 DOI: 10.1016/j.molcel.2022.12.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/19/2022] [Accepted: 12/21/2022] [Indexed: 01/15/2023]
Abstract
Errors occurring during DNA replication can result in inaccurate replication, incomplete replication, or re-replication, resulting in genome instability that can lead to diseases such as cancer or disorders such as autism. A great deal of progress has been made toward understanding the entire process of DNA replication in eukaryotes, including the mechanism of initiation and its control. This review focuses on the current understanding of how the origin recognition complex (ORC) contributes to determining the location of replication initiation in the multiple chromosomes within eukaryotic cells, as well as methods for mapping the location and temporal patterning of DNA replication. Origin specification and configuration vary substantially between eukaryotic species and in some cases co-evolved with gene-silencing mechanisms. We discuss the possibility that centromeres and origins of DNA replication were originally derived from a common element and later separated during evolution.
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Affiliation(s)
- Yixin Hu
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA; Program in Molecular and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Bruce Stillman
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.
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63
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Gallitto M, Zhang Z. The evolving tale of Pol2 function. Genes Dev 2023; 37:72-73. [PMID: 36813532 PMCID: PMC10069447 DOI: 10.1101/gad.350527.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
DNA replication is complex and highly regulated, and DNA replication errors can lead to human diseases such as cancer. DNA polymerase ε (polε) is a key player in DNA replication and contains a large subunit called POLE, which possesses both a DNA polymerase domain and a 3'-5' exonuclease domain (EXO). Mutations at the EXO domain and other missense mutations on POLE with unknown significance have been detected in a variety of human cancers. Based on cancer genome databases, Meng and colleagues (pp. 74-79) previously identified several missense mutations in POPS (pol2 family-specific catalytic core peripheral subdomain), and mutations at the conserved residues of yeast Pol2 (pol2-REL) showed reduced DNA synthesis and growth. In this issue of Genes & Development, Meng and colleagues (pp. 74-79) found unexpectedly that mutations at the EXO domain rescue the growth defects of pol2-REL. They further discovered that EXO-mediated polymerase backtracking impedes forward movement of the enzyme when POPS is defective, revealing a novel interplay between the EXO domain and POPS of Pol2 for efficient DNA synthesis. Additional molecular insight into this interplay will likely inform the impact of cancer-associated mutations found in both the EXO domain and POPS on tumorigenesis and uncover future novel therapeutic strategies.
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Affiliation(s)
- Matthew Gallitto
- Institute for Cancer Genetics, Department of Pediatrics, Department of Genetics and Development, Irving Cancer Research Center, Columbia University, New York, New York 10032, USA
| | - Zhiguo Zhang
- Institute for Cancer Genetics, Department of Pediatrics, Department of Genetics and Development, Irving Cancer Research Center, Columbia University, New York, New York 10032, USA
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64
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Li N, Gao N, Zhai Y. DDK promotes DNA replication initiation: Mechanistic and structural insights. Curr Opin Struct Biol 2023; 78:102504. [PMID: 36525878 DOI: 10.1016/j.sbi.2022.102504] [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: 08/31/2022] [Revised: 10/25/2022] [Accepted: 11/15/2022] [Indexed: 12/15/2022]
Abstract
DNA replication initiation in eukaryotes is tightly regulated through two cell-cycle specific processes, replication licensing to install inactive minichromosome maintenance (MCM) double-hexamers (DH) on origins in early G1 phase and origin firing to assemble and activate Cdc45-Mcm2-7-GINS (CMG) helicases upon S phase entry. Two kinases, cyclin-dependent kinase (CDK) and Dbf4-dependent kinase (DDK), are responsible for driving the association of replication factors with the MCM-DH to form CMG helicases for origin melting and DNA unwinding and eventually replisomes for bi-directional DNA synthesis. In recent years, cryo-electron microscopy studies have generated a collection of structural snapshots for the stepwise assembly and remodeling of the replication initiation machineries, creating a framework for understanding the regulation of this fundamental process at a molecular level. Very recent progress is the structural characterization of the elusive MCM-DH-DDK complex, which provides insights into mechanisms of kinase activation, substrate recognition and selection, as well as molecular role of DDK-mediated MCM-DH phosphorylation in helicase activation.
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Affiliation(s)
- Ningning Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China; National Biomedical Imaging Center, Peking University, Beijing, China.
| | - Yuanliang Zhai
- School of Biological Sciences, The University of Hong Kong, Hong Kong.
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65
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The CMG helicase and cancer: a tumor "engine" and weakness with missing mutations. Oncogene 2023; 42:473-490. [PMID: 36522488 PMCID: PMC9948756 DOI: 10.1038/s41388-022-02572-8] [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: 08/05/2022] [Revised: 12/01/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022]
Abstract
The replicative Cdc45-MCM-GINS (CMG) helicase is a large protein complex that functions in the DNA melting and unwinding steps as a component of replisomes during DNA replication in mammalian cells. Although the CMG performs this important role in cell growth, the CMG is not a simple bystander in cell cycle events. Components of the CMG, specifically the MCM precursors, are also involved in maintaining genomic stability by regulating DNA replication fork speeds, facilitating recovery from replicative stresses, and preventing consequential DNA damage. Given these important functions, MCM/CMG complexes are highly regulated by growth factors such as TGF-ß1 and by signaling factors such as Myc, Cyclin E, and the retinoblastoma protein. Mismanagement of MCM/CMG complexes when these signaling mediators are deregulated, and in the absence of the tumor suppressor protein p53, leads to increased genomic instability and is a contributor to tumorigenic transformation and tumor heterogeneity. The goal of this review is to provide insight into the mechanisms and dynamics by which the CMG is regulated during its assembly and activation in mammalian genomes, and how errors in CMG regulation due to oncogenic changes promote tumorigenesis. Finally, and most importantly, we highlight the emerging understanding of the CMG helicase as an exploitable vulnerability and novel target for therapeutic intervention in cancer.
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66
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Rhind N. DNA replication timing: Biochemical mechanisms and biological significance. Bioessays 2022; 44:e2200097. [PMID: 36125226 PMCID: PMC9783711 DOI: 10.1002/bies.202200097] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 12/27/2022]
Abstract
The regulation of DNA replication is a fascinating biological problem both from a mechanistic angle-How is replication timing regulated?-and from an evolutionary one-Why is replication timing regulated? Recent work has provided significant insight into the first question. Detailed biochemical understanding of the mechanism and regulation of replication initiation has made possible robust hypotheses for how replication timing is regulated. Moreover, technical progress, including high-throughput, single-molecule mapping of replication initiation and single-cell assays of replication timing, has allowed for direct testing of these hypotheses in mammalian cells. This work has consolidated the conclusion that differential replication timing is a consequence of the varying probability of replication origin initiation. The second question is more difficult to directly address experimentally. Nonetheless, plausible hypotheses can be made and one-that replication timing contributes to the regulation of chromatin structure-has received new experimental support.
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Affiliation(s)
- Nicholas Rhind
- Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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67
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A DNA Replication Fork-centric View of the Budding Yeast DNA Damage Response. DNA Repair (Amst) 2022; 119:103393. [DOI: 10.1016/j.dnarep.2022.103393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 11/23/2022]
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68
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Gutierrez C. A Journey to the Core of the Plant Cell Cycle. Int J Mol Sci 2022; 23:8154. [PMID: 35897730 PMCID: PMC9330084 DOI: 10.3390/ijms23158154] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/16/2022] [Accepted: 07/21/2022] [Indexed: 02/04/2023] Open
Abstract
Production of new cells as a result of progression through the cell division cycle is a fundamental biological process for the perpetuation of both unicellular and multicellular organisms. In the case of plants, their developmental strategies and their largely sessile nature has imposed a series of evolutionary trends. Studies of the plant cell division cycle began with cytological and physiological approaches in the 1950s and 1960s. The decade of 1990 marked a turn point with the increasing development of novel cellular and molecular protocols combined with advances in genetics and, later, genomics, leading to an exponential growth of the field. In this article, I review the current status of plant cell cycle studies but also discuss early studies and the relevance of a multidisciplinary background as a source of innovative questions and answers. In addition to advances in a deeper understanding of the plant cell cycle machinery, current studies focus on the intimate interaction of cell cycle components with almost every aspect of plant biology.
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Affiliation(s)
- Crisanto Gutierrez
- Centro de Biologia Molecular Severo Ochoa, CSIC-UAM, Nicolas Cabrera 1, Cantoblanco, 28049 Madrid, Spain
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69
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Dimerization of Firing Factors for Replication Origin Activation in Eukaryotes: A Crucial Process for Simultaneous Assembly of Bidirectional Replication Forks? BIOLOGY 2022; 11:biology11060928. [PMID: 35741449 PMCID: PMC9219616 DOI: 10.3390/biology11060928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/13/2022] [Accepted: 06/15/2022] [Indexed: 11/17/2022]
Abstract
Simple Summary Chromosomal DNA must be faithfully duplicated and segregated into two daughter cells when cells divide. DNA synthesis initiates from specific regions known as the origins of replication. When it starts, a pair of the replication fork is established, and each replication fork moves away from replication origins. In each replication fork, replicative helicase unwinds DNA from a double to a single strand. This implies that two sets of active helicase are generated from each replication origin. To make this possible, two sets of replicative helicases are loaded onto replication origins as inactive dimers first. When S-phase specific cyclin-dependent kinases, S-CDKs, are activated, the inactive helicase is converted into the active helicase with the aid of other factors called firing factors. Although two sets of firing factors seem to be required to activate two sets of helicase, it is largely unknown whether two sets of firing factors function simultaneously to establish bidirectional replication forks in a coordinated way. We introduce our current understanding of firing factor dimerization and discuss its potential contribution to bidirectional replication fork formation in this review. Abstract Controlling the activity of the heterohexameric Mcm2–7 replicative helicase is crucial for regulation of replication origin activity in eukaryotes. Because bidirectional replication forks are generated from every replication origin, when origins are licensed for replication in the first step of DNA replication, two inactive Mcm2–7 heterohexiameric complexes are loaded around double stranded DNA as a head-to-head double hexamer. The helicases are subsequently activated via a ‘firing’ reaction, in which the Mcm2–7 double hexamer is converted into two active helicase units, the CMG complex, by firing factors. Dimerization of firing factors may contribute to this process by allowing simultaneous activation of two sets of helicases and thus efficient assembly of bidirectional replication forks. An example of this is dimerization of the firing factor Sld3/Treslin/Ticrr via its binding partner, Sld7/MTBP. In organisms in which no Sld7 ortholog has been identified, such as the fission yeast Schizosaccharomyces pombe, Sld3 itself has a dimerization domain, and it has been suggested that this self-interaction is crucial for the firing reaction in this organism. Dimerization induces a conformational change in Sdl3 that appears to be critical for the firing reaction. Moreover, Mcm10 also seems to be regulated by self-interaction in yeasts. Although it is not yet clear to what extent dimerization of firing factors contributes to the firing reaction in eukaryotes, we discuss the possible roles of firing factor dimerization in simultaneous helicase activation.
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Gillespie PJ, Blow JJ. DDK: The Outsourced Kinase of Chromosome Maintenance. BIOLOGY 2022; 11:biology11060877. [PMID: 35741398 PMCID: PMC9220011 DOI: 10.3390/biology11060877] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 05/31/2022] [Accepted: 06/02/2022] [Indexed: 11/16/2022]
Abstract
The maintenance of genomic stability during the mitotic cell-cycle not only demands that the DNA is duplicated and repaired with high fidelity, but that following DNA replication the chromatin composition is perpetuated and that the duplicated chromatids remain tethered until their anaphase segregation. The coordination of these processes during S phase is achieved by both cyclin-dependent kinase, CDK, and Dbf4-dependent kinase, DDK. CDK orchestrates the activation of DDK at the G1-to-S transition, acting as the ‘global’ regulator of S phase and cell-cycle progression, whilst ‘local’ control of the initiation of DNA replication and repair and their coordination with the re-formation of local chromatin environments and the establishment of chromatid cohesion are delegated to DDK. Here, we discuss the regulation and the multiple roles of DDK in ensuring chromosome maintenance. Regulation of replication initiation by DDK has long been known to involve phosphorylation of MCM2-7 subunits, but more recent results have indicated that Treslin:MTBP might also be important substrates. Molecular mechanisms by which DDK regulates replisome stability and replicated chromatid cohesion are less well understood, though important new insights have been reported recently. We discuss how the ‘outsourcing’ of activities required for chromosome maintenance to DDK allows CDK to maintain outright control of S phase progression and the cell-cycle phase transitions whilst permitting ongoing chromatin replication and cohesion establishment to be completed and achieved faithfully.
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