1
|
Piguet B, Houseley J. Transcription as source of genetic heterogeneity in budding yeast. Yeast 2024; 41:171-185. [PMID: 38196235 DOI: 10.1002/yea.3926] [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: 10/07/2023] [Revised: 12/10/2023] [Accepted: 12/20/2023] [Indexed: 01/11/2024] Open
Abstract
Transcription presents challenges to genome stability both directly, by altering genome topology and exposing single-stranded DNA to chemical insults and nucleases, and indirectly by introducing obstacles to the DNA replication machinery. Such obstacles include the RNA polymerase holoenzyme itself, DNA-bound regulatory factors, G-quadruplexes and RNA-DNA hybrid structures known as R-loops. Here, we review the detrimental impacts of transcription on genome stability in budding yeast, as well as the mitigating effects of transcription-coupled nucleotide excision repair and of systems that maintain DNA replication fork processivity and integrity. Interactions between DNA replication and transcription have particular potential to induce mutation and structural variation, but we conclude that such interactions must have only minor effects on DNA replication by the replisome with little if any direct mutagenic outcome. However, transcription can significantly impair the fidelity of replication fork rescue mechanisms, particularly Break Induced Replication, which is used to restart collapsed replication forks when other means fail. This leads to de novo mutations, structural variation and extrachromosomal circular DNA formation that contribute to genetic heterogeneity, but only under particular conditions and in particular genetic contexts, ensuring that the bulk of the genome remains extremely stable despite the seemingly frequent interactions between transcription and DNA replication.
Collapse
|
2
|
Shaw AE, Whitted JE, Mihelich MN, Reitman HJ, Timmerman AJ, Schauer GD. Revised Mechanism of Hydroxyurea Induced Cell Cycle Arrest and an Improved Alternative. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.02.583010. [PMID: 38496404 PMCID: PMC10942336 DOI: 10.1101/2024.03.02.583010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Replication stress describes various types of endogenous and exogenous challenges to DNA replication in S-phase. Stress during this critical process results in helicase-polymerase decoupling at replication forks, triggering the S-phase checkpoint, which orchestrates global replication fork stalling and delayed entry into G2. The replication stressor most often used to induce the checkpoint response is hydroxyurea (HU), a chemotherapeutic agent. The primary mechanism of S-phase checkpoint activation by HU has thus far been considered to be a reduction of dNTP synthesis by inhibition of ribonucleotide reductase (RNR), leading to helicase-polymerase decoupling and subsequent activation of the checkpoint, mediated by the replisome associated effector kinase Mrc1. In contrast, we observe that HU causes cell cycle arrest in budding yeast independent of both the Mrc1-mediated replication checkpoint response and the Psk1-Mrc1 oxidative signaling pathway. We demonstrate a direct relationship between HU incubation and reactive oxygen species (ROS) production in yeast nuclei. We further observe that ROS strongly inhibits the in vitro polymerase activity of replicative polymerases (Pols), Pol α, Pol δ, and Pol ε, causing polymerase complex dissociation and subsequent loss of DNA substrate binding, likely through oxidation of their integral iron sulfur Fe-S clusters. Finally, we present "RNR-deg," a genetically engineered alternative to HU in yeast with greatly increased specificity of RNR inhibition, allowing researchers to achieve fast, nontoxic, and more readily reversible checkpoint activation compared to HU, avoiding harmful ROS generation and associated downstream cellular effects that may confound interpretation of results.
Collapse
Affiliation(s)
- Alisa E Shaw
- Department of Biochemistry and Molecular Biology, Colorado State University, CO, USA
| | - Jackson E Whitted
- Department of Biochemistry and Molecular Biology, Colorado State University, CO, USA
| | - Mattias N Mihelich
- Department of Biochemistry and Molecular Biology, Colorado State University, CO, USA
| | - Hannah J Reitman
- Department of Biochemistry and Molecular Biology, Colorado State University, CO, USA
| | - Adam J Timmerman
- Department of Biochemistry and Molecular Biology, Colorado State University, CO, USA
| | - Grant D Schauer
- Department of Biochemistry and Molecular Biology, Colorado State University, CO, USA
| |
Collapse
|
3
|
Kumar C, Remus D. Looping out of control: R-loops in transcription-replication conflict. Chromosoma 2024; 133:37-56. [PMID: 37419963 PMCID: PMC10771546 DOI: 10.1007/s00412-023-00804-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/09/2023]
Abstract
Transcription-replication conflict is a major cause of replication stress that arises when replication forks collide with the transcription machinery. Replication fork stalling at sites of transcription compromises chromosome replication fidelity and can induce DNA damage with potentially deleterious consequences for genome stability and organismal health. The block to DNA replication by the transcription machinery is complex and can involve stalled or elongating RNA polymerases, promoter-bound transcription factor complexes, or DNA topology constraints. In addition, studies over the past two decades have identified co-transcriptional R-loops as a major source for impairment of DNA replication forks at active genes. However, how R-loops impede DNA replication at the molecular level is incompletely understood. Current evidence suggests that RNA:DNA hybrids, DNA secondary structures, stalled RNA polymerases, and condensed chromatin states associated with R-loops contribute to the of fork progression. Moreover, since both R-loops and replication forks are intrinsically asymmetric structures, the outcome of R-loop-replisome collisions is influenced by collision orientation. Collectively, the data suggest that the impact of R-loops on DNA replication is highly dependent on their specific structural composition. Here, we will summarize our current understanding of the molecular basis for R-loop-induced replication fork progression defects.
Collapse
Affiliation(s)
- Charanya Kumar
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA
| | - Dirk Remus
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA.
| |
Collapse
|
4
|
Joshua IM, Lin M, Mardjuki A, Mazzola A, Höfken T. A Protein-Protein Interaction Analysis Suggests a Wide Range of New Functions for the p21-Activated Kinase (PAK) Ste20. Int J Mol Sci 2023; 24:15916. [PMID: 37958899 PMCID: PMC10647699 DOI: 10.3390/ijms242115916] [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: 09/20/2023] [Revised: 10/25/2023] [Accepted: 10/30/2023] [Indexed: 11/15/2023] Open
Abstract
The p21-activated kinases (PAKs) are important signaling proteins. They contribute to a surprisingly wide range of cellular processes and play critical roles in a number of human diseases including cancer, neurological disorders and cardiac diseases. To get a better understanding of PAK functions, mechanisms and integration of various cellular activities, we screened for proteins that bind to the budding yeast PAK Ste20 as an example, using the split-ubiquitin technique. We identified 56 proteins, most of them not described previously as Ste20 interactors. The proteins fall into a small number of functional categories such as vesicle transport and translation. We analyzed the roles of Ste20 in glucose metabolism and gene expression further. Ste20 has a well-established role in the adaptation to changing environmental conditions through the stimulation of mitogen-activated protein kinase (MAPK) pathways which eventually leads to transcription factor activation. This includes filamentous growth, an adaptation to nutrient depletion. Here we show that Ste20 also induces filamentous growth through interaction with nuclear proteins such as Sac3, Ctk1 and Hmt1, key regulators of gene expression. Combining our observations and the data published by others, we suggest that Ste20 has several new and unexpected functions.
Collapse
Affiliation(s)
| | - Meng Lin
- Institute of Biochemistry, Kiel University, 24118 Kiel, Germany
| | - Ariestia Mardjuki
- Division of Biosciences, Brunel University London, Uxbridge UB8 3PH, UK; (I.M.J.)
| | - Alessandra Mazzola
- Division of Biosciences, Brunel University London, Uxbridge UB8 3PH, UK; (I.M.J.)
- Department of Biopathology and Medical and Forensic Biotechnologies, University of Palermo, 90133 Palermo, Italy
| | - Thomas Höfken
- Division of Biosciences, Brunel University London, Uxbridge UB8 3PH, UK; (I.M.J.)
- Institute of Biochemistry, Kiel University, 24118 Kiel, Germany
| |
Collapse
|
5
|
Wagner ER, Gasch AP. Advances in S. cerevisiae Engineering for Xylose Fermentation and Biofuel Production: Balancing Growth, Metabolism, and Defense. J Fungi (Basel) 2023; 9:786. [PMID: 37623557 PMCID: PMC10455348 DOI: 10.3390/jof9080786] [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: 06/14/2023] [Revised: 07/19/2023] [Accepted: 07/24/2023] [Indexed: 08/26/2023] Open
Abstract
Genetically engineering microorganisms to produce chemicals has changed the industrialized world. The budding yeast Saccharomyces cerevisiae is frequently used in industry due to its genetic tractability and unique metabolic capabilities. S. cerevisiae has been engineered to produce novel compounds from diverse sugars found in lignocellulosic biomass, including pentose sugars, like xylose, not recognized by the organism. Engineering high flux toward novel compounds has proved to be more challenging than anticipated since simply introducing pathway components is often not enough. Several studies show that the rewiring of upstream signaling is required to direct products toward pathways of interest, but doing so can diminish stress tolerance, which is important in industrial conditions. As an example of these challenges, we reviewed S. cerevisiae engineering efforts, enabling anaerobic xylose fermentation as a model system and showcasing the regulatory interplay's controlling growth, metabolism, and stress defense. Enabling xylose fermentation in S. cerevisiae requires the introduction of several key metabolic enzymes but also regulatory rewiring of three signaling pathways at the intersection of the growth and stress defense responses: the RAS/PKA, Snf1, and high osmolarity glycerol (HOG) pathways. The current studies reviewed here suggest the modulation of global signaling pathways should be adopted into biorefinery microbial engineering pipelines to increase efficient product yields.
Collapse
Affiliation(s)
- Ellen R. Wagner
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI 53706, USA
- Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Audrey P. Gasch
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI 53706, USA
- Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI 53706, USA
| |
Collapse
|
6
|
Irvali D, Schlottmann FP, Muralidhara P, Nadelson I, Kleemann K, Wood NE, Doncic A, Ewald JC. When yeast cells change their mind: cell cycle "Start" is reversible under starvation. EMBO J 2023; 42:e110321. [PMID: 36420556 PMCID: PMC9841329 DOI: 10.15252/embj.2021110321] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 11/03/2022] [Accepted: 11/10/2022] [Indexed: 11/25/2022] Open
Abstract
Eukaryotic cells decide in late G1 phase of the cell cycle whether to commit to another round of division. This point of cell cycle commitment is termed "Restriction Point" in mammals and "Start" in the budding yeast Saccharomyces cerevisiae. At Start, yeast cells integrate multiple signals such as pheromones and nutrients, and will not pass Start if nutrients are lacking. However, how cells respond to nutrient depletion after the Start decision remains poorly understood. Here, we analyze how post-Start cells respond to nutrient depletion, by monitoring Whi5, the cell cycle inhibitor whose export from the nucleus determines Start. Surprisingly, we find that cells that have passed Start can re-import Whi5 into the nucleus. In these cells, the positive feedback loop activating G1/S transcription is interrupted, and the Whi5 repressor re-binds DNA. Cells which re-import Whi5 become again sensitive to mating pheromone, like pre-Start cells, and CDK activation can occur a second time upon replenishment of nutrients. These results demonstrate that upon starvation, the commitment decision at Start can be reversed. We therefore propose that cell cycle commitment in yeast is a multi-step process, similar to what has been suggested for mammalian cells.
Collapse
Affiliation(s)
- Deniz Irvali
- Interfaculty Institute of Cell Biology, University of Tuebingen, Tuebingen, Germany
| | - Fabian P Schlottmann
- Interfaculty Institute of Cell Biology, University of Tuebingen, Tuebingen, Germany
| | | | - Iliya Nadelson
- Interfaculty Institute of Cell Biology, University of Tuebingen, Tuebingen, Germany
| | - Katja Kleemann
- Interfaculty Institute of Cell Biology, University of Tuebingen, Tuebingen, Germany
| | - N Ezgi Wood
- The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Andreas Doncic
- The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jennifer C Ewald
- Interfaculty Institute of Cell Biology, University of Tuebingen, Tuebingen, Germany
| |
Collapse
|
7
|
Claspin-Dependent and -Independent Chk1 Activation by a Panel of Biological Stresses. Biomolecules 2023; 13:biom13010125. [PMID: 36671510 PMCID: PMC9855620 DOI: 10.3390/biom13010125] [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: 11/30/2022] [Revised: 01/02/2023] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Replication stress has been suggested to be an ultimate trigger of carcinogenesis. Oncogenic signal, such as overexpression of CyclinE, has been shown to induce replication stress. Here, we show that various biological stresses, including heat, oxidative stress, osmotic stress, LPS, hypoxia, and arsenate induce activation of Chk1, a key effector kinase for replication checkpoint. Some of these stresses indeed reduce the fork rate, inhibiting DNA replication. Analyses of Chk1 activation in the cell population with Western analyses showed that Chk1 activation by these stresses is largely dependent on Claspin. On the other hand, single cell analyses with Fucci cells indicated that while Chk1 activation during S phase is dependent on Claspin, that in G1 is mostly independent of Claspin. We propose that various biological stresses activate Chk1 either directly by stalling DNA replication fork or by some other mechanism that does not involve replication inhibition. The former pathway predominantly occurs in S phase and depends on Claspin, while the latter pathway, which may occur throughout the cell cycle, is largely independent of Claspin. Our findings provide evidence for novel links between replication stress checkpoint and other biological stresses and point to the presence of replication-independent mechanisms of Chk1 activation in mammalian cells.
Collapse
|
8
|
Yang CC, Masai H. Claspin is Required for Growth Recovery from Serum Starvation through Regulating the PI3K-PDK1-mTOR Pathway in Mammalian Cells. Mol Cell Biol 2023; 43:1-21. [PMID: 36720467 PMCID: PMC9936878 DOI: 10.1080/10985549.2022.2160598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Claspin plays multiple important roles in regulation of DNA replication as a mediator for the cellular response to replication stress, an integral replication fork factor that facilitates replication fork progression and a factor that promotes initiation by recruiting Cdc7 kinase. Here, we report a novel role of Claspin in growth recovery from serum starvation, which requires the activation of PI3 kinase (PI3K)-PDK1-Akt-mTOR pathways. In the absence of Claspin, cells do not proceed into S phase and eventually die partially in a ROS- and p53-dependent manner. Claspin directly interacts with PI3K and mTOR, and is required for activation of PI3K-PDK1-mTOR and for that of mTOR downstream factors, p70S6K and 4EBP1, but not for p38 MAPK cascade during the recovery from serum starvation. PDK1 physically interacts with Claspin, notably with CKBD, in a manner dependent on phosphorylation of the latter protein, and is required for interaction of mTOR with Claspin. Thus, Claspin plays a novel role as a key regulator for nutrition-induced proliferation/survival signaling by activating the mTOR pathway. The results also suggest a possibility that Claspin may serve as a common mediator that receives signals from different PI3K-related kinases and transmit them to specific downstream kinases.
Collapse
Affiliation(s)
- Chi-Chun Yang
- Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Hisao Masai
- Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| |
Collapse
|
9
|
Ulsamer A, Martínez-Limón A, Bader S, Rodríguez-Acebes S, Freire R, Méndez J, de Nadal E, Posas F. Regulation of Claspin by the p38 stress-activated protein kinase protects cells from DNA damage. Cell Rep 2022; 40:111375. [PMID: 36130506 DOI: 10.1016/j.celrep.2022.111375] [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: 06/08/2022] [Revised: 07/07/2022] [Accepted: 08/25/2022] [Indexed: 11/03/2022] Open
Abstract
Stress-activated protein kinases (SAPKs) enhance survival in response to environmental changes. In yeast, the Hog1 SAPK and Mrc1, a protein required for DNA replication, define a safeguard mechanism that allows eukaryotic cells to prevent genomic instability upon stress during S-phase. Here we show that, in mammals, the p38 SAPK and Claspin-the functional homolog of Mrc1-protect cells from DNA damage upon osmostress during S-phase. We demonstrate that p38 phosphorylates Claspin and either the mutation of the p38-phosphorylation sites in Claspin or p38 inhibition suppresses the protective role of Claspin on DNA damage. In addition, wild-type Claspin but not the p38-unphosphorylatable mutant has a protective effect on cell survival in response to cisplatin treatment. These findings reveal a role of Claspin in response to chemotherapeutic drugs. Thus, this pathway protects S-phase integrity from different insults and it is conserved from yeast to mammals.
Collapse
Affiliation(s)
- Arnau Ulsamer
- Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Adrián Martínez-Limón
- Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain
| | - Sina Bader
- Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Sara Rodríguez-Acebes
- DNA Replication Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), 3 Melchor Fernández Almagro, 28029 Madrid, Spain
| | - Raimundo Freire
- Unidad de Investigación, Hospital Universitario de Canarias-FIISC, Ofra s/n, 38320 La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas, Universidad de La Laguna, 38200 La Laguna, Tenerife, Spain; Universidad Fernando Pessoa Canarias, 35450 Las Palmas de Gran Canaria, Spain
| | - Juan Méndez
- DNA Replication Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), 3 Melchor Fernández Almagro, 28029 Madrid, Spain
| | - Eulàlia de Nadal
- Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain.
| | - Francesc Posas
- Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain.
| |
Collapse
|
10
|
Blomberg A. Yeast osmoregulation - glycerol still in pole position. FEMS Yeast Res 2022; 22:6655991. [PMID: 35927716 PMCID: PMC9428294 DOI: 10.1093/femsyr/foac035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/29/2022] [Accepted: 08/02/2022] [Indexed: 11/14/2022] Open
Abstract
In response to osmotic dehydration cells sense, signal, alter gene expression, and metabolically counterbalance osmotic differences. The main compatible solute/osmolyte that accumulates in yeast cells is glycerol, which is produced from the glycolytic intermediate dihydroxyacetone phosphate. This review covers recent advancements in understanding mechanisms involved in sensing, signaling, cell-cycle delays, transcriptional responses as well as post-translational modifications on key proteins in osmoregulation. The protein kinase Hog1 is a key-player in many of these events, however, there is also a growing body of evidence for important Hog1-independent mechanisms playing vital roles. Several missing links in our understanding of osmoregulation will be discussed and future avenues for research proposed. The review highlights that this rather simple experimental system—salt/sorbitol and yeast—has developed into an enormously potent model system unravelling important fundamental aspects in biology.
Collapse
Affiliation(s)
- Anders Blomberg
- Dept. of Chemistry and Molecular Biology, University of Gothenburg, Sweden
| |
Collapse
|
11
|
Substrates of the MAPK Slt2: Shaping Yeast Cell Integrity. J Fungi (Basel) 2022; 8:jof8040368. [PMID: 35448599 PMCID: PMC9031059 DOI: 10.3390/jof8040368] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 03/30/2022] [Accepted: 03/31/2022] [Indexed: 02/04/2023] Open
Abstract
The cell wall integrity (CWI) MAPK pathway of budding yeast Saccharomyces cerevisiae is specialized in responding to cell wall damage, but ongoing research shows that it participates in many other stressful conditions, suggesting that it has functional diversity. The output of this pathway is mainly driven by the activity of the MAPK Slt2, which regulates important processes for yeast physiology such as fine-tuning of signaling through the CWI and other pathways, transcriptional activation in response to cell wall damage, cell cycle, or determination of the fate of some organelles. To this end, Slt2 precisely phosphorylates protein substrates, modulating their activity, stability, protein interaction, and subcellular localization. Here, after recapitulating the methods that have been employed in the discovery of proteins phosphorylated by Slt2, we review the bona fide substrates of this MAPK and the growing set of candidates still to be confirmed. In the context of the complexity of MAPK signaling regulation, we discuss how Slt2 determines yeast cell integrity through phosphorylation of these substrates. Increasing data from large-scale analyses and the available methodological approaches pave the road to early identification of new Slt2 substrates and functions.
Collapse
|
12
|
de Nadal E, Posas F. OUP accepted manuscript. FEMS Yeast Res 2022; 22:6543702. [PMID: 35254447 PMCID: PMC8953452 DOI: 10.1093/femsyr/foac013] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/28/2022] [Accepted: 03/03/2022] [Indexed: 11/15/2022] Open
Affiliation(s)
- Eulàlia de Nadal
- Corresponding author: Institute for Research in Biomedicine (IRB Barcelona) Parc Científic de Barcelona c/ Baldiri Reixac, 10. 08028 Barcelona - Spain. E-mail:
| | - Francesc Posas
- Corresponding author: Institute for Research in Biomedicine (IRB Barcelona) Parc Científic de Barcelona c/ Baldiri Reixac, 10. 08028 Barcelona - Spain. E-mail:
| |
Collapse
|
13
|
The CWI Pathway: A Versatile Toolbox to Arrest Cell-Cycle Progression. J Fungi (Basel) 2021; 7:jof7121041. [PMID: 34947023 PMCID: PMC8704918 DOI: 10.3390/jof7121041] [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: 11/08/2021] [Revised: 11/29/2021] [Accepted: 12/02/2021] [Indexed: 02/02/2023] Open
Abstract
Cell-signaling pathways are essential for cells to respond and adapt to changes in their environmental conditions. The cell-wall integrity (CWI) pathway of Saccharomyces cerevisiae is activated by environmental stresses, compounds, and morphogenetic processes that compromise the cell wall, orchestrating the appropriate cellular response to cope with these adverse conditions. During cell-cycle progression, the CWI pathway is activated in periods of polarized growth, such as budding or cytokinesis, regulating cell-wall biosynthesis and the actin cytoskeleton. Importantly, accumulated evidence has indicated a reciprocal regulation of the cell-cycle regulatory system by the CWI pathway. In this paper, we describe how the CWI pathway regulates the main cell-cycle transitions in response to cell-surface perturbance to delay cell-cycle progression. In particular, it affects the Start transcriptional program and the initiation of DNA replication at the G1/S transition, and entry and progression through mitosis. We also describe the involvement of the CWI pathway in the response to genotoxic stress and its connection with the DNA integrity checkpoint, the mechanism that ensures the correct transmission of genetic material and cell survival. Thus, the CWI pathway emerges as a master brake that stops cell-cycle progression when cells are coping with distinct unfavorable conditions.
Collapse
|
14
|
Hurst V, Challa K, Jonas F, Forey R, Sack R, Seebacher J, Schmid CD, Barkai N, Shimada K, Gasser SM, Poli J. A regulatory phosphorylation site on Mec1 controls chromatin occupancy of RNA polymerases during replication stress. EMBO J 2021; 40:e108439. [PMID: 34569643 PMCID: PMC8561635 DOI: 10.15252/embj.2021108439] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 09/08/2021] [Accepted: 09/10/2021] [Indexed: 01/16/2023] Open
Abstract
Upon replication stress, budding yeast checkpoint kinase Mec1ATR triggers the downregulation of transcription, thereby reducing the level of RNA polymerase (RNAP) on chromatin to facilitate replication fork progression. Here, we identify a hydroxyurea-induced phosphorylation site on Mec1, Mec1-S1991, that contributes to the eviction of RNAPII and RNAPIII during replication stress. The expression of the non-phosphorylatable mec1-S1991A mutant reduces replication fork progression genome-wide and compromises survival on hydroxyurea. This defect can be suppressed by destabilizing chromatin-bound RNAPII through a TAP fusion to its Rpb3 subunit, suggesting that lethality in mec1-S1991A mutants arises from replication-transcription conflicts. Coincident with a failure to repress gene expression on hydroxyurea in mec1-S1991A cells, highly transcribed genes such as GAL1 remain bound at nuclear pores. Consistently, we find that nuclear pore proteins and factors controlling RNAPII and RNAPIII are phosphorylated in a Mec1-dependent manner on hydroxyurea. Moreover, we show that Mec1 kinase also contributes to reduced RNAPII occupancy on chromatin during an unperturbed S phase by promoting degradation of the Rpb1 subunit.
Collapse
Affiliation(s)
- Verena Hurst
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,Faculty of Natural Sciences, University of Basel, Basel, Switzerland
| | - Kiran Challa
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Felix Jonas
- Departments of Molecular Genetics and Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel
| | - Romain Forey
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe labélisée Ligue contre le Cancer, Montpellier, France
| | - Ragna Sack
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Jan Seebacher
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Christoph D Schmid
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Naama Barkai
- Departments of Molecular Genetics and Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel
| | - Kenji Shimada
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,Faculty of Natural Sciences, University of Basel, Basel, Switzerland
| | - Jérôme Poli
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe labélisée Ligue contre le Cancer, Montpellier, France
| |
Collapse
|
15
|
St Germain C, Zhao H, Barlow JH. Transcription-Replication Collisions-A Series of Unfortunate Events. Biomolecules 2021; 11:1249. [PMID: 34439915 PMCID: PMC8391903 DOI: 10.3390/biom11081249] [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: 07/21/2021] [Revised: 08/12/2021] [Accepted: 08/17/2021] [Indexed: 02/07/2023] Open
Abstract
Transcription-replication interactions occur when DNA replication encounters genomic regions undergoing transcription. Both replication and transcription are essential for life and use the same DNA template making conflicts unavoidable. R-loops, DNA supercoiling, DNA secondary structure, and chromatin-binding proteins are all potential obstacles for processive replication or transcription and pose an even more potent threat to genome integrity when these processes co-occur. It is critical to maintaining high fidelity and processivity of transcription and replication while navigating through a complex chromatin environment, highlighting the importance of defining cellular pathways regulating transcription-replication interaction formation, evasion, and resolution. Here we discuss how transcription influences replication fork stability, and the safeguards that have evolved to navigate transcription-replication interactions and maintain genome integrity in mammalian cells.
Collapse
Affiliation(s)
- Commodore St Germain
- School of Mathematics and Science, Solano Community College, 4000 Suisun Valley Road, Fairfield, CA 94534, USA
- Department of Microbiology and Molecular Genetics, University of California Davis, One Shields Avenue, Davis, CA 95616, USA;
| | - Hongchang Zhao
- Department of Microbiology and Molecular Genetics, University of California Davis, One Shields Avenue, Davis, CA 95616, USA;
| | - Jacqueline H. Barlow
- Department of Microbiology and Molecular Genetics, University of California Davis, One Shields Avenue, Davis, CA 95616, USA;
| |
Collapse
|
16
|
Kemiha S, Poli J, Lin YL, Lengronne A, Pasero P. Toxic R-loops: Cause or consequence of replication stress? DNA Repair (Amst) 2021; 107:103199. [PMID: 34399314 DOI: 10.1016/j.dnarep.2021.103199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/28/2021] [Accepted: 07/30/2021] [Indexed: 01/08/2023]
Abstract
Transcription-replication conflicts (TRCs) represent a potential source of endogenous replication stress (RS) and genomic instability in eukaryotic cells but the mechanisms that underlie this instability remain poorly understood. Part of the problem could come from non-B DNA structures called R-loops, which are formed of a RNA:DNA hybrid and a displaced ssDNA loop. In this review, we discuss different scenarios in which R-loops directly or indirectly interfere with DNA replication. We also present other types of TRCs that may not depend on R-loops to impede fork progression. Finally, we discuss alternative models in which toxic RNA:DNA hybrids form at stalled forks as a consequence - but not a cause - of replication stress and interfere with replication resumption.
Collapse
Affiliation(s)
- Samira Kemiha
- Institut de Génétique Humaine, CNRS et Université de Montpellier, Equipe labélisée Ligue contre le Cancer, Montpellier, France
| | - Jérôme Poli
- Institut de Génétique Humaine, CNRS et Université de Montpellier, Equipe labélisée Ligue contre le Cancer, Montpellier, France
| | - Yea-Lih Lin
- Institut de Génétique Humaine, CNRS et Université de Montpellier, Equipe labélisée Ligue contre le Cancer, Montpellier, France
| | - Armelle Lengronne
- Institut de Génétique Humaine, CNRS et Université de Montpellier, Equipe labélisée Ligue contre le Cancer, Montpellier, France
| | - Philippe Pasero
- Institut de Génétique Humaine, CNRS et Université de Montpellier, Equipe labélisée Ligue contre le Cancer, Montpellier, France.
| |
Collapse
|
17
|
Lalonde M, Trauner M, Werner M, Hamperl S. Consequences and Resolution of Transcription-Replication Conflicts. Life (Basel) 2021; 11:life11070637. [PMID: 34209204 PMCID: PMC8303131 DOI: 10.3390/life11070637] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 06/28/2021] [Accepted: 06/28/2021] [Indexed: 11/17/2022] Open
Abstract
Transcription–replication conflicts occur when the two critical cellular machineries responsible for gene expression and genome duplication collide with each other on the same genomic location. Although both prokaryotic and eukaryotic cells have evolved multiple mechanisms to coordinate these processes on individual chromosomes, it is now clear that conflicts can arise due to aberrant transcription regulation and premature proliferation, leading to DNA replication stress and genomic instability. As both are considered hallmarks of aging and human diseases such as cancer, understanding the cellular consequences of conflicts is of paramount importance. In this article, we summarize our current knowledge on where and when collisions occur and how these encounters affect the genome and chromatin landscape of cells. Finally, we conclude with the different cellular pathways and multiple mechanisms that cells have put in place at conflict sites to ensure the resolution of conflicts and accurate genome duplication.
Collapse
|
18
|
Jiménez J, Queralt E, Posas F, de Nadal E. The regulation of Net1/Cdc14 by the Hog1 MAPK upon osmostress unravels a new mechanism regulating mitosis. Cell Cycle 2020; 19:2105-2118. [PMID: 32794416 PMCID: PMC7513861 DOI: 10.1080/15384101.2020.1804222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
During evolution, cells have developed a plethora of mechanisms to optimize survival in a changing and unpredictable environment. In this regard, they have evolved networks that include environmental sensors, signaling transduction molecules and response mechanisms. Hog1 (yeast) and p38 (mammals) stress-activated protein kinases (SAPKs) are activated upon stress and they drive a full collection of cell adaptive responses aimed to maximize survival. SAPKs are extensively used to learn about the mechanisms through which cells adapt to changing environments. In addition to regulating gene expression and metabolism, SAPKs control cell cycle progression. In this review, we will discuss the latest findings related to the SAPK-driven regulation of mitosis upon osmostress in yeast.
Collapse
Affiliation(s)
- Javier Jiménez
- Departament De Ciències Experimentals I De La Salut, Universitat Pompeu Fabra (UPF) , Barcelona, Spain.,Department of Ciències Bàsiques, Facultat De Medicina I Ciències De La Salut, Universitat Internacional De Catalunya , Barcelona, Spain
| | - Ethel Queralt
- Cell Cycle Group, Institut d'Investigacions Biomèdica De Bellvitge (IDIBELL), L'Hospitalet De Llobregat , Barcelona, Spain
| | - Francesc Posas
- Departament De Ciències Experimentals I De La Salut, Universitat Pompeu Fabra (UPF) , Barcelona, Spain.,Institute for Research in Biomedicine (IRB Barcelona), the Barcelona Institute of Science and Technology , 08028 Barcelona, Spain
| | - Eulàlia de Nadal
- Departament De Ciències Experimentals I De La Salut, Universitat Pompeu Fabra (UPF) , Barcelona, Spain.,Institute for Research in Biomedicine (IRB Barcelona), the Barcelona Institute of Science and Technology , 08028 Barcelona, Spain
| |
Collapse
|
19
|
Ethanol exposure increases mutation rate through error-prone polymerases. Nat Commun 2020; 11:3664. [PMID: 32694532 PMCID: PMC7374746 DOI: 10.1038/s41467-020-17447-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 06/30/2020] [Indexed: 12/19/2022] Open
Abstract
Ethanol is a ubiquitous environmental stressor that is toxic to all lifeforms. Here, we use the model eukaryote Saccharomyces cerevisiae to show that exposure to sublethal ethanol concentrations causes DNA replication stress and an increased mutation rate. Specifically, we find that ethanol slows down replication and affects localization of Mrc1, a conserved protein that helps stabilize the replisome. In addition, ethanol exposure also results in the recruitment of error-prone DNA polymerases to the replication fork. Interestingly, preventing this recruitment through mutagenesis of the PCNA/Pol30 polymerase clamp or deleting specific error-prone polymerases abolishes the mutagenic effect of ethanol. Taken together, this suggests that the mutagenic effect depends on a complex mechanism, where dysfunctional replication forks lead to recruitment of error-prone polymerases. Apart from providing a general mechanistic framework for the mutagenic effect of ethanol, our findings may also provide a route to better understand and prevent ethanol-associated carcinogenesis in higher eukaryotes. Whereas the toxic effects of ethanol are well-documented, the underlying mechanism is obscure. This study uses the eukaryotic model S. cerevisiae to reveal how exposure to sublethal ethanol concentrations causes DNA replication stress and an increased mutation rate.
Collapse
|
20
|
Abstract
Proper chromosome segregation is critical for the maintenance of genomic information in every cell division, which is required for cell survival. Cells have orchestrated a myriad of control mechanisms to guarantee proper chromosome segregation. Upon stress, cells induce a number of adaptive responses to maximize survival that range from regulation of gene expression to control of cell-cycle progression. We have found here that in response to osmostress, cells also regulate mitosis to ensure proper telomeric and rDNA segregation during adaptation. Osmostress induces a Hog1-dependent delay of cell-cycle progression in early mitosis by phosphorylating Net1, thereby impairing timely nucleolar release and activation of Cdc14, core elements of mitosis regulation. Thus, Hog1 activation prevents segregation defects to maximize survival. Adaptation to environmental changes is crucial for cell fitness. In Saccharomyces cerevisiae, variations in external osmolarity trigger the activation of the stress-activated protein kinase Hog1 (high-osmolarity glycerol 1), which regulates gene expression, metabolism, and cell-cycle progression. The activation of this kinase leads to the regulation of G1, S, and G2 phases of the cell cycle to prevent genome instability and promote cell survival. Here we show that Hog1 delays mitotic exit when cells are stressed during metaphase. Hog1 phosphorylates the nucleolar protein Net1, altering its affinity for the phosphatase Cdc14, whose activity is essential for mitotic exit and completion of the cell cycle. The untimely release of Cdc14 from the nucleolus upon activation of Hog1 is linked to a defect in ribosomal DNA (rDNA) and telomere segregation, and it ultimately delays cell division. A mutant of Net1 that cannot be phosphorylated by Hog1 displays reduced viability upon osmostress. Thus, Hog1 contributes to maximizing cell survival upon stress by regulating mitotic exit.
Collapse
|
21
|
Feu S, Unzueta F, Llopis A, Semple JI, Ercilla A, Guaita-Esteruelas S, Jaumot M, Freire R, Agell N. OZF is a Claspin-interacting protein essential to maintain the replication fork progression rate under replication stress. FASEB J 2020; 34:6907-6919. [PMID: 32267586 DOI: 10.1096/fj.201901926r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 03/10/2020] [Accepted: 03/16/2020] [Indexed: 12/12/2022]
Abstract
DNA replication is essential for cell proliferation and is one of the cell cycle stages where DNA is more vulnerable. Replication stress is a prominent property of tumor cells and an emerging target for cancer therapy. Although it is not directly involved in nucleotide incorporation, Claspin is a protein with relevant functions in DNA replication. It harbors a DNA-binding domain that interacts preferentially with branched or forked DNA molecules. It also acts as a platform for the interaction of proteins related to DNA damage checkpoint activation, DNA repair, DNA replication origin firing, and fork progression. In order to find new proteins potentially involved in the regulation of DNA replication, we performed a two-hybrid screen to discover new Claspin-binding proteins. This system allowed us to identify the zinc-finger protein OZF (ZNF146) as a new Claspin-interacting protein. OZF is also present at replication forks and co-immunoprecipitates not only with Claspin but also with other replisome components. Interestingly, OZF depletion does not affect DNA replication in a normal cell cycle, but its depletion induces a reduction in the fork progression rate under replication stress conditions. Our results suggest that OZF is a Claspin-binding protein with a specific function in fork progression under replication stress.
Collapse
Affiliation(s)
- Sonia Feu
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
| | - Fernando Unzueta
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
| | - Alba Llopis
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
| | | | - Amaia Ercilla
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
| | - Sandra Guaita-Esteruelas
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
| | - Montserrat Jaumot
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
| | - Raimundo Freire
- Unidad de Investigación, Hospital Universitario de Canarias, FIISC, La Laguna, Spain.,Instituto de Tecnologías Biomédicas, Universidad de La Laguna, La Laguna, Spain.,Facultad de Ciencias de la Salud, Universidad Fernando Pessoa Canarias, Las Palmas de Gran Canaria, Spain
| | - Neus Agell
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
22
|
Appanah R, Lones EC, Aiello U, Libri D, De Piccoli G. Sen1 Is Recruited to Replication Forks via Ctf4 and Mrc1 and Promotes Genome Stability. Cell Rep 2020; 30:2094-2105.e9. [PMID: 32075754 PMCID: PMC7034062 DOI: 10.1016/j.celrep.2020.01.087] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 09/06/2019] [Accepted: 01/24/2020] [Indexed: 01/21/2023] Open
Abstract
DNA replication and RNA transcription compete for the same substrate during S phase. Cells have evolved several mechanisms to minimize such conflicts. Here, we identify the mechanism by which the transcription termination helicase Sen1 associates with replisomes. We show that the N terminus of Sen1 is both sufficient and necessary for replisome association and that it binds to the replisome via the components Ctf4 and Mrc1. We generated a separation of function mutant, sen1-3, which abolishes replisome binding without affecting transcription termination. We observe that the sen1-3 mutants show increased genome instability and recombination levels. Moreover, sen1-3 is synthetically defective with mutations in genes involved in RNA metabolism and the S phase checkpoint. RNH1 overexpression suppresses defects in the former, but not the latter. These findings illustrate how Sen1 plays a key function at replication forks during DNA replication to promote fork progression and chromosome stability.
Collapse
Affiliation(s)
- Rowin Appanah
- Warwick Medical School, University of Warwick, CV4 7AL Coventry, UK
| | | | - Umberto Aiello
- Institut Jacques Monod, CNRS, UMR7592, Université Paris Diderot, Paris Sorbonne Cité, Paris, France
| | - Domenico Libri
- Institut Jacques Monod, CNRS, UMR7592, Université Paris Diderot, Paris Sorbonne Cité, Paris, France
| | | |
Collapse
|
23
|
Morafraile EC, Hänni C, Allen G, Zeisner T, Clarke C, Johnson MC, Santos MM, Carroll L, Minchell NE, Baxter J, Banks P, Lydall D, Zegerman P. Checkpoint inhibition of origin firing prevents DNA topological stress. Genes Dev 2019; 33:1539-1554. [PMID: 31624083 PMCID: PMC6824463 DOI: 10.1101/gad.328682.119] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 09/13/2019] [Indexed: 12/22/2022]
Abstract
A universal feature of DNA damage and replication stress in eukaryotes is the activation of a checkpoint-kinase response. In S-phase, the checkpoint inhibits replication initiation, yet the function of this global block to origin firing remains unknown. To establish the physiological roles of this arm of the checkpoint, we analyzed separation of function mutants in the budding yeast Saccharomyces cerevisiae that allow global origin firing upon replication stress, despite an otherwise normal checkpoint response. Using genetic screens, we show that lack of the checkpoint-block to origin firing results in a dependence on pathways required for the resolution of topological problems. Failure to inhibit replication initiation indeed causes increased DNA catenation, resulting in DNA damage and chromosome loss. We further show that such topological stress is not only a consequence of a failed checkpoint response but also occurs in an unperturbed S-phase when too many origins fire simultaneously. Together we reveal that the role of limiting the number of replication initiation events is to prevent DNA topological problems, which may be relevant for the treatment of cancer with both topoisomerase and checkpoint inhibitors.
Collapse
Affiliation(s)
- Esther C Morafraile
- Wellcome Trust/Cancer Research UK Gurdon Institute and Department of Biochemistry, University of Cambridge CB2 1QN, United Kingdom
| | - Christine Hänni
- Wellcome Trust/Cancer Research UK Gurdon Institute and Department of Biochemistry, University of Cambridge CB2 1QN, United Kingdom
| | - George Allen
- Wellcome Trust/Cancer Research UK Gurdon Institute and Department of Biochemistry, University of Cambridge CB2 1QN, United Kingdom
| | - Theresa Zeisner
- Wellcome Trust/Cancer Research UK Gurdon Institute and Department of Biochemistry, University of Cambridge CB2 1QN, United Kingdom
| | - Caroline Clarke
- Wellcome Trust/Cancer Research UK Gurdon Institute and Department of Biochemistry, University of Cambridge CB2 1QN, United Kingdom
| | - Mark C Johnson
- Wellcome Trust/Cancer Research UK Gurdon Institute and Department of Biochemistry, University of Cambridge CB2 1QN, United Kingdom
| | - Miguel M Santos
- Wellcome Trust/Cancer Research UK Gurdon Institute and Department of Biochemistry, University of Cambridge CB2 1QN, United Kingdom
| | - Lauren Carroll
- Wellcome Trust/Cancer Research UK Gurdon Institute and Department of Biochemistry, University of Cambridge CB2 1QN, United Kingdom
| | - Nicola E Minchell
- 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
| | - Peter Banks
- Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Dave Lydall
- Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Philip Zegerman
- Wellcome Trust/Cancer Research UK Gurdon Institute and Department of Biochemistry, University of Cambridge CB2 1QN, United Kingdom
| |
Collapse
|
24
|
Abstract
Genome replication involves dealing with obstacles that can result from DNA damage but also from chromatin alterations, topological stress, tightly bound proteins or non-B DNA structures such as R loops. Experimental evidence reveals that an engaged transcription machinery at the DNA can either enhance such obstacles or be an obstacle itself. Thus, transcription can become a potentially hazardous process promoting localized replication fork hindrance and stress, which would ultimately cause genome instability, a hallmark of cancer cells. Understanding the causes behind transcription-replication conflicts as well as how the cell resolves them to sustain genome integrity is the aim of this review.
Collapse
|
25
|
Smits VAJ, Cabrera E, Freire R, Gillespie DA. Claspin – checkpoint adaptor and
DNA
replication factor. FEBS J 2018; 286:441-455. [DOI: 10.1111/febs.14594] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 06/13/2018] [Accepted: 06/20/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Veronique A. J. Smits
- Hospital Universitario de Canarias Unidad de Investigación La Laguna Tenerife Spain
- Facultad de Medicina Instituto de Tecnologías Biomédicas Centro de Investigaciones Biomédicas de Canarias Universidad de La Laguna Tenerife Spain
| | - Elisa Cabrera
- Hospital Universitario de Canarias Unidad de Investigación La Laguna Tenerife Spain
- Facultad de Medicina Instituto de Tecnologías Biomédicas Centro de Investigaciones Biomédicas de Canarias Universidad de La Laguna Tenerife Spain
| | - Raimundo Freire
- Hospital Universitario de Canarias Unidad de Investigación La Laguna Tenerife Spain
- Facultad de Medicina Instituto de Tecnologías Biomédicas Centro de Investigaciones Biomédicas de Canarias Universidad de La Laguna Tenerife Spain
| | - David A. Gillespie
- Facultad de Medicina Instituto de Tecnologías Biomédicas Centro de Investigaciones Biomédicas de Canarias Universidad de La Laguna Tenerife Spain
| |
Collapse
|
26
|
Canal B, Duch A, Posas F, de Nadal E. A novel mechanism for the prevention of transcription replication conflicts. Mol Cell Oncol 2018; 5:e1451233. [PMID: 30250903 PMCID: PMC6149842 DOI: 10.1080/23723556.2018.1451233] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 03/06/2018] [Accepted: 03/06/2018] [Indexed: 11/18/2022]
Abstract
Transcription and replication complexes can coincide in space and time. Such coincidences may result in collisions that trigger genomic instability. The phosphorylation of Mrc1 by different signaling kinases is part of a general mechanism that serves to delay replication in response to different stresses that trigger a massive transcriptional response in S phase. This mechanism prevents Transcription-Replication Conflicts and maintains genomic integrity in response to unscheduled massive transcription during S phase.
Collapse
Affiliation(s)
- Berta Canal
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Alba Duch
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Francesc Posas
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Eulàlia de Nadal
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| |
Collapse
|