1
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Göder A, Maric CA, Rainey MD, O’Connor A, Cazzaniga C, Shamavu D, Cadoret JC, Santocanale C. DBF4, not DRF1, is the crucial regulator of CDC7 kinase at replication forks. J Cell Biol 2024; 223:e202402144. [PMID: 38865090 PMCID: PMC11169917 DOI: 10.1083/jcb.202402144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/02/2024] [Accepted: 05/04/2024] [Indexed: 06/13/2024] Open
Abstract
CDC7 kinase is crucial for DNA replication initiation and is involved in fork processing and replication stress response. Human CDC7 requires the binding of either DBF4 or DRF1 for its activity. However, it is unclear whether the two regulatory subunits target CDC7 to a specific set of substrates, thus having different biological functions, or if they act redundantly. Using genome editing technology, we generated isogenic cell lines deficient in either DBF4 or DRF1: these cells are viable but present signs of genomic instability, indicating that both can independently support CDC7 for bulk DNA replication. Nonetheless, DBF4-deficient cells show altered replication efficiency, partial deficiency in MCM helicase phosphorylation, and alterations in the replication timing of discrete genomic regions. Notably, we find that CDC7 function at replication forks is entirely dependent on DBF4 and not on DRF1. Thus, DBF4 is the primary regulator of CDC7 activity, mediating most of its functions in unperturbed DNA replication and upon replication interference.
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Affiliation(s)
- Anja Göder
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | | | - Michael D. Rainey
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Aisling O’Connor
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Chiara Cazzaniga
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Daniel Shamavu
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | | | - Corrado Santocanale
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
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2
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PTEN Dual Lipid- and Protein-Phosphatase Function in Tumor Progression. Cancers (Basel) 2022; 14:cancers14153666. [PMID: 35954330 PMCID: PMC9367293 DOI: 10.3390/cancers14153666] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/17/2022] [Accepted: 07/22/2022] [Indexed: 11/17/2022] Open
Abstract
Simple Summary Phosphatase and tensin homolog deleted on chromosome ten (PTEN) is a multifunctional tumor suppressor with protein- and lipid-phosphatase activities. The inactivation of PTEN is commonly found in all human cancers and is correlated with tumor progression. PTEN-lipid-phosphatase activity has been well documented to dephosphorylate phosphatidylinositol-3, 4, 5-phosphate (PIP3), which hinders cell growth and survival by dampening the PI3K and AKT signaling activity. PTEN-protein-phosphatase activity is less well studied and understood. Recent studies have reported that PTEN-protein-phosphatase activity dephosphorylates the different proteins and acts in various cell functions. We here review the PTEN mutations and protein-phosphatase substrates in tumor progression. We aim to address the gap in our understanding as to how PTEN protein phosphatase contributes to its tumor-suppression functions. Abstract PTEN is the second most highly mutated tumor suppressor in cancer, following only p53. The PTEN protein functions as a phosphatase with lipid- and protein-phosphatase activity. PTEN-lipid-phosphatase activity dephosphorylates PIP3 to form PIP2, and it then antagonizes PI3K and blocks the activation of AKT, while its protein-phosphatase activity dephosphorylates different protein substrates and plays various roles in tumorigenesis. Here, we review the PTEN mutations and protein-phosphatase substrates in tumorigenesis and metastasis. Our purpose is to clarify how PTEN protein phosphatase contributes to its tumor-suppressive functions through PI3K-independent activities.
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3
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Guerra B, Doktor TK, Frederiksen SB, Somyajit K, Andresen BS. Essential role of CK2α for the interaction and stability of replication fork factors during DNA synthesis and activation of the S-phase checkpoint. Cell Mol Life Sci 2022; 79:339. [PMID: 35661926 PMCID: PMC9166893 DOI: 10.1007/s00018-022-04374-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 05/09/2022] [Accepted: 05/12/2022] [Indexed: 11/25/2022]
Abstract
The ataxia telangiectasia mutated and Rad3-related (ATR)-CHK1 pathway is the major signalling cascade activated in response to DNA replication stress. This pathway is associated with the core of the DNA replication machinery comprising CDC45, the replicative MCM2-7 hexamer, GINS (altogether forming the CMG complex), primase-polymerase (POLε, -α, and -δ) complex, and additional fork protection factors such as AND-1, CLASPIN (CLSPN), and TIMELESS/TIPIN. In this study, we report that functional protein kinase CK2α is critical for preserving replisome integrity and for mounting S-phase checkpoint signalling. We find that CDC45, CLSPN and MCM7 are novel CK2α interacting partners and these interactions are particularly important for maintenance of stable MCM7-CDC45, ATRIP-ATR-MCM7, and ATR-CLSPN protein complexes. Consistently, cells depleted of CK2α and treated with hydroxyurea display compromised replisome integrity, reduced chromatin binding of checkpoint mediator CLSPN, attenuated ATR-mediated S-phase checkpoint and delayed recovery of stalled forks. In further support of this, differential gene expression analysis by RNA-sequencing revealed that down-regulation of CK2α accompanies global shutdown of genes that are implicated in the S-phase checkpoint. These findings add to our understanding of the molecular mechanisms involved in DNA replication by showing that the protein kinase CK2α is essential for maintaining the stability of the replisome machinery and for optimizing ATR-CHK1 signalling activation upon replication stress.
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Affiliation(s)
- Barbara Guerra
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.
| | - Thomas K Doktor
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Sabrina B Frederiksen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Kumar Somyajit
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Brage S Andresen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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4
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González‐Garrido C, Prado F. Novel insights into the roles of Cdc7 in response to replication stress. FEBS J 2022. [DOI: 10.1111/febs.16456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/01/2022] [Accepted: 04/07/2022] [Indexed: 11/26/2022]
Affiliation(s)
- Cristina González‐Garrido
- Centro Andaluz de Biología Molecular y Medicina Regenerativa–CABIMER Consejo Superior de Investigaciones Científicas Universidad de Sevilla Universidad Pablo de Olavide Spain
| | - Félix Prado
- Centro Andaluz de Biología Molecular y Medicina Regenerativa–CABIMER Consejo Superior de Investigaciones Científicas Universidad de Sevilla Universidad Pablo de Olavide Spain
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5
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Manco G, Lacerra G, Porzio E, Catara G. ADP-Ribosylation Post-Translational Modification: An Overview with a Focus on RNA Biology and New Pharmacological Perspectives. Biomolecules 2022; 12:biom12030443. [PMID: 35327636 PMCID: PMC8946771 DOI: 10.3390/biom12030443] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/02/2022] [Accepted: 03/10/2022] [Indexed: 02/04/2023] Open
Abstract
Cellular functions are regulated through the gene expression program by the transcription of new messenger RNAs (mRNAs), alternative RNA splicing, and protein synthesis. To this end, the post-translational modifications (PTMs) of proteins add another layer of complexity, creating a continuously fine-tuned regulatory network. ADP-ribosylation (ADPr) is an ancient reversible modification of cellular macromolecules, regulating a multitude of key functional processes as diverse as DNA damage repair (DDR), transcriptional regulation, intracellular transport, immune and stress responses, and cell survival. Additionally, due to the emerging role of ADP-ribosylation in pathological processes, ADP-ribosyltransferases (ARTs), the enzymes involved in ADPr, are attracting growing interest as new drug targets. In this review, an overview of human ARTs and their related biological functions is provided, mainly focusing on the regulation of ADP-ribosyltransferase Diphtheria toxin-like enzymes (ARTD)-dependent RNA functions. Finally, in order to unravel novel gene functional relationships, we propose the analysis of an inventory of human gene clusters, including ARTDs, which share conserved sequences at 3′ untranslated regions (UTRs).
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Affiliation(s)
- Giuseppe Manco
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino 111, 80131 Naples, Italy;
- Correspondence: (G.M.); (G.C.)
| | - Giuseppina Lacerra
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso”, National Research Council of Italy, Via P. Castellino 111, 80131 Naples, Italy;
| | - Elena Porzio
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino 111, 80131 Naples, Italy;
| | - Giuliana Catara
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino 111, 80131 Naples, Italy;
- Correspondence: (G.M.); (G.C.)
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6
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Martin JC, Sims JR, Gupta A, Hagoel TJ, Gao L, Lynch ML, Woloszynska A, Melendy T, Kane JF, Kuechle J, Ohm JE. CDC7 kinase (DDK) inhibition disrupts DNA replication leading to mitotic catastrophe in Ewing sarcoma. Cell Death Discov 2022; 8:85. [PMID: 35220396 PMCID: PMC8882187 DOI: 10.1038/s41420-022-00877-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 01/26/2022] [Accepted: 02/08/2022] [Indexed: 12/27/2022] Open
Abstract
Ewing sarcoma is the second most common bone malignancy in children and adolescents. In recent years, a large body of evidence has emerged that suggests Ewing tumors harbor large amounts of replication stress (RS). CDC7, also known as DDK (DBF4-dependent kinase), is a serine/threonine kinase that is involved in a diverse array of cellular functions including the regulation of DNA replication initiation and activation of the RS response. Due to DDK's diverse roles during replication, coupled with the fact that there is an increased level of RS within Ewing tumors, we hypothesized that Ewing sarcoma cells would be particularly vulnerable to DDK inhibition. Here, we report that DDK inhibition resulted a significant reduction in cell viability and the induction of apoptosis, specifically in Ewing sarcoma cells. Treatment with DDK inhibitors dramatically reduced the rate of replication, prolonged S-phase, and led to a pronounced increase in phospho-CDC2 (Y15), indicating delay of mitotic entry. The induction of cell death corresponded to mitotic exit and G1 entry, suggesting improper mitotic progression. In accordance with this, we find that DDK inhibition caused premature mitotic entry resulting in mitotic abnormalities such as anaphase bridges, lagging chromosomes, and cells with >2 poles in Ewing sarcoma cells. This abnormal progression through mitosis resulted in mitotic catastrophe as evidenced by the formation of micronuclei and induction of DNA damage. Together, these findings suggest that DDK activity is required for the faithful and timely completion of DNA replication in Ewing cells and that DDK inhibition may present a viable therapeutic strategy for the treatment of Ewing sarcoma.
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Affiliation(s)
- Jeffrey C. Martin
- grid.240614.50000 0001 2181 8635Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY USA
| | - Jennie R. Sims
- grid.240614.50000 0001 2181 8635Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY USA
| | - Ajay Gupta
- grid.273335.30000 0004 1936 9887Division of Pediatric Oncology, Roswell Park Comprehensive Cancer Center, Department of Pediatrics, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY USA
| | - Tamara J. Hagoel
- grid.273335.30000 0004 1936 9887Division of Pediatric Oncology, Roswell Park Comprehensive Cancer Center, Department of Pediatrics, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY USA
| | - Lingqiu Gao
- grid.240614.50000 0001 2181 8635Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY USA
| | - Miranda L. Lynch
- grid.249447.80000 0004 0422 1994Hauptman-Woodward Medical Research Institute, Buffalo, NY USA
| | - Anna Woloszynska
- grid.240614.50000 0001 2181 8635Department of Pharmacology & Therapeutics, Roswell Park Comprehensive Cancer Center, Buffalo, NY USA
| | - Thomas Melendy
- grid.273335.30000 0004 1936 9887Department of Microbiology and Immunology, State University of New York at Buffalo, Buffalo, NY USA
| | - Jeremy F. Kane
- grid.240614.50000 0001 2181 8635Department of Surgery, Roswell Park Comprehensive Cancer Center, Buffalo, NY USA
| | - Joseph Kuechle
- grid.240614.50000 0001 2181 8635Department of Surgery, Roswell Park Comprehensive Cancer Center, Buffalo, NY USA
| | - Joyce E. Ohm
- grid.240614.50000 0001 2181 8635Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY USA
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7
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Huang D, Chowdhury S, Wang H, Savage SR, Ivey RG, Kennedy JJ, Whiteaker JR, Lin C, Hou X, Oberg AL, Larson MC, Eskandari N, Delisi DA, Gentile S, Huntoon CJ, Voytovich UJ, Shire ZJ, Yu Q, Gygi SP, Hoofnagle AN, Herbert ZT, Lorentzen TD, Calinawan A, Karnitz LM, Weroha SJ, Kaufmann SH, Zhang B, Wang P, Birrer MJ, Paulovich AG. Multiomic analysis identifies CPT1A as a potential therapeutic target in platinum-refractory, high-grade serous ovarian cancer. Cell Rep Med 2021; 2:100471. [PMID: 35028612 PMCID: PMC8714940 DOI: 10.1016/j.xcrm.2021.100471] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 09/24/2021] [Accepted: 11/19/2021] [Indexed: 12/14/2022]
Abstract
Resistance to platinum compounds is a major determinant of patient survival in high-grade serous ovarian cancer (HGSOC). To understand mechanisms of platinum resistance and identify potential therapeutic targets in resistant HGSOC, we generated a data resource composed of dynamic (±carboplatin) protein, post-translational modification, and RNA sequencing (RNA-seq) profiles from intra-patient cell line pairs derived from 3 HGSOC patients before and after acquiring platinum resistance. These profiles reveal extensive responses to carboplatin that differ between sensitive and resistant cells. Higher fatty acid oxidation (FAO) pathway expression is associated with platinum resistance, and both pharmacologic inhibition and CRISPR knockout of carnitine palmitoyltransferase 1A (CPT1A), which represents a rate limiting step of FAO, sensitize HGSOC cells to platinum. The results are further validated in patient-derived xenograft models, indicating that CPT1A is a candidate therapeutic target to overcome platinum resistance. All multiomic data can be queried via an intuitive gene-query user interface (https://sites.google.com/view/ptrc-cell-line).
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Affiliation(s)
- Dongqing Huang
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Shrabanti Chowdhury
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Hong Wang
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Sara R. Savage
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Richard G. Ivey
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Jacob J. Kennedy
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Jeffrey R. Whiteaker
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Chenwei Lin
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Xiaonan Hou
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Ann L. Oberg
- Department of Quantitative Health Sciences, Division of Computational Biology, Mayo Clinic, Rochester, MN 55905, USA
| | - Melissa C. Larson
- Department of Quantitative Health Sciences, Division of Clinical Trials and Biostatistics, Mayo Clinic, Rochester, MN 55905, USA
| | - Najmeh Eskandari
- Division of Hematology and Oncology, Department of Medicine, University of Illinois, Chicago, IL 60612, USA
| | - Davide A. Delisi
- Division of Hematology and Oncology, Department of Medicine, University of Illinois, Chicago, IL 60612, USA
| | - Saverio Gentile
- Division of Hematology and Oncology, Department of Medicine, University of Illinois, Chicago, IL 60612, USA
| | | | - Uliana J. Voytovich
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Zahra J. Shire
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Qing Yu
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Steven P. Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Andrew N. Hoofnagle
- Department of Lab Medicine, University of Washington, Seattle, WA 98195, USA
| | - Zachary T. Herbert
- Molecular Biology Core Facilities, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Travis D. Lorentzen
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Anna Calinawan
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | - S. John Weroha
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Bing Zhang
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Pei Wang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Michael J. Birrer
- University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Amanda G. Paulovich
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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8
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Aricthota S, Haldar D. DDK/Hsk1 phosphorylates and targets fission yeast histone deacetylase Hst4 for degradation to stabilize stalled DNA replication forks. eLife 2021; 10:70787. [PMID: 34608864 PMCID: PMC8565929 DOI: 10.7554/elife.70787] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 10/01/2021] [Indexed: 01/01/2023] Open
Abstract
In eukaryotes, paused replication forks are prone to collapse, which leads to genomic instability, a hallmark of cancer. Dbf4-dependent kinase (DDK)/Hsk1Cdc7 is a conserved replication initiator kinase with conflicting roles in replication stress response. Here, we show that fission yeast DDK/Hsk1 phosphorylates sirtuin, Hst4 upon replication stress at C-terminal serine residues. Phosphorylation of Hst4 by DDK marks it for degradation via the ubiquitin ligase SCFpof3. Phosphorylation-defective hst4 mutant (4SA-hst4) displays defective recovery from replication stress, faulty fork restart, slow S-phase progression and decreased viability. The highly conserved fork protection complex (FPC) stabilizes stalled replication forks. We found that the recruitment of FPC components, Swi1 and Mcl1 to the chromatin is compromised in the 4SA-hst4 mutant, although whole cell levels increased. These defects are dependent upon H3K56ac and independent of intra S-phase checkpoint activation. Finally, we show conservation of H3K56ac-dependent regulation of Timeless, Tipin, and And-1 in human cells. We propose that degradation of Hst4 via DDK increases H3K56ac, changing the chromatin state in the vicinity of stalled forks facilitating recruitment and function of FPC. Overall, this study identified a crucial role of DDK and FPC in the regulation of replication stress response with implications in cancer therapeutics.
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Affiliation(s)
- Shalini Aricthota
- Laboratory of Chromatin Biology and Epigenetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.,Graduate Studies, Manipal Academy of Higher Education, Manipal, India
| | - Devyani Haldar
- Laboratory of Chromatin Biology and Epigenetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
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9
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Upregulation of CDC7 Associated with Cervical Cancer Incidence and Development. BIOMED RESEARCH INTERNATIONAL 2021; 2021:6663367. [PMID: 33763482 PMCID: PMC7952153 DOI: 10.1155/2021/6663367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/29/2021] [Accepted: 02/19/2021] [Indexed: 11/25/2022]
Abstract
Background Cervical cancer is a common malignant tumor of women. Using integrated bioinformatics, this study identified key disease-causing genes in cervical cancer that may provide effective biomarkers or therapeutic targets for early diagnosis and treatment. Results We used high-throughput sequencing data from the Gene Expression Omnibus (GEO) to identify new cervical cancer biomarkers. The GSE63678 dataset was downloaded. The data was analyzed via bioinformatics methods, and 61 differentially expressed genes were obtained. These differential genes were analyzed by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichments analyses. GO analysis demonstrated that the basic biological functions of differential genes were mostly regulating cell division, mitotic nuclear division, and immune response. Analysis of the KEGG pathway showed the primary involved in the cell cycle, p53 signaling pathway, and cytokine-cytokine receptor interactions. Using TCGA database to query differential expression of differential genes in cervical cancer, the CDC7 gene was found to be highly expressed. In silico analysis of protein interactions using the STRING database revealed that CDC7 interacts with many proteins. These findings were then validated in vitro with immunohistochemistry and qRt-PCR to confirm that CDC7 is highly expressed in cervical cancer tissues. Cell function tests demonstrated that inhibition of CDC7 expression could inhibit the proliferation and migration of cervical cancer HeLa and SiHa cells and promote apoptosis. Conclusion With comprehensive bioinformatics combined with clinical and cellular function analysis, CDC7 is important to the development of cervical cancer. Targeting of this biomarker may improve the early diagnosis and treatment of cervical cancer.
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10
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Jones MJK, Gelot C, Munk S, Koren A, Kawasoe Y, George KA, Santos RE, Olsen JV, McCarroll SA, Frattini MG, Takahashi TS, Jallepalli PV. Human DDK rescues stalled forks and counteracts checkpoint inhibition at unfired origins to complete DNA replication. Mol Cell 2021; 81:426-441.e8. [PMID: 33545059 DOI: 10.1016/j.molcel.2021.01.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 09/25/2020] [Accepted: 01/05/2021] [Indexed: 12/14/2022]
Abstract
Eukaryotic genomes replicate via spatially and temporally regulated origin firing. Cyclin-dependent kinase (CDK) and Dbf4-dependent kinase (DDK) promote origin firing, whereas the S phase checkpoint limits firing to prevent nucleotide and RPA exhaustion. We used chemical genetics to interrogate human DDK with maximum precision, dissect its relationship with the S phase checkpoint, and identify DDK substrates. We show that DDK inhibition (DDKi) leads to graded suppression of origin firing and fork arrest. S phase checkpoint inhibition rescued origin firing in DDKi cells and DDK-depleted Xenopus egg extracts. DDKi also impairs RPA loading, nascent-strand protection, and fork restart. Via quantitative phosphoproteomics, we identify the BRCA1-associated (BRCA1-A) complex subunit MERIT40 and the cohesin accessory subunit PDS5B as DDK effectors in fork protection and restart. Phosphorylation neutralizes autoinhibition mediated by intrinsically disordered regions in both substrates. Our results reveal mechanisms through which DDK controls the duplication of large vertebrate genomes.
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Affiliation(s)
- Mathew J K Jones
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD 4102, Australia.
| | - Camille Gelot
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Stephanie Munk
- University of Copenhagen and Novo Nordisk Foundation Center for Protein Research, Copenhagen 2200, Denmark
| | - Amnon Koren
- Cornell University, Department of Molecular Biology and Genetics, Ithaca, NY 14853, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Yoshitaka Kawasoe
- Graduate School of Science, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kelly A George
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Ruth E Santos
- Division of Hematology/Oncology, Columbia University Medical Center, New York, NY 10032, USA
| | - Jesper V Olsen
- University of Copenhagen and Novo Nordisk Foundation Center for Protein Research, Copenhagen 2200, Denmark
| | | | - Mark G Frattini
- Division of Hematology/Oncology, Columbia University Medical Center, New York, NY 10032, USA
| | - Tatsuro S Takahashi
- Graduate School of Science, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
| | - Prasad V Jallepalli
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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11
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Rainey MD, Quinlan A, Cazzaniga C, Mijic S, Martella O, Krietsch J, Göder A, Lopes M, Santocanale C. CDC7 kinase promotes MRE11 fork processing, modulating fork speed and chromosomal breakage. EMBO Rep 2020; 21:e48920. [PMID: 32496651 PMCID: PMC7403700 DOI: 10.15252/embr.201948920] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 11/24/2022] Open
Abstract
The CDC7 kinase is essential for the activation of DNA replication origins and has been implicated in the replication stress response. Using a highly specific chemical inhibitor and a chemical genetic approach, we now show that CDC7 activity is required to coordinate multiple MRE11‐dependent processes occurring at replication forks, independently from its role in origin firing. CDC7 localizes at replication forks and, similarly to MRE11, mediates active slowing of fork progression upon mild topoisomerase inhibition. Both proteins are also retained on stalled forks, where they promote fork processing and restart. Moreover, MRE11 phosphorylation and localization at replication factories are progressively lost upon CDC7 inhibition. Finally, CDC7 activity at reversed forks is required for their pathological MRE11‐dependent degradation in BRCA2‐deficient cells. Thus, upon replication interference CDC7 is a key regulator of fork progression, processing and integrity. These results highlight a dual role for CDC7 in replication, modulating both initiation and elongation steps of DNA synthesis, and identify a key intervention point for anticancer therapies exploiting replication interference.
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Affiliation(s)
- Michael D Rainey
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Aisling Quinlan
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Chiara Cazzaniga
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Sofija Mijic
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Oliviano Martella
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Jana Krietsch
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Anja Göder
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Massimo Lopes
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Corrado Santocanale
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
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12
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Choi EH, Kim KP. E2F1 facilitates DNA break repair by localizing to break sites and enhancing the expression of homologous recombination factors. Exp Mol Med 2019; 51:1-12. [PMID: 31534120 PMCID: PMC6802646 DOI: 10.1038/s12276-019-0307-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 06/16/2019] [Accepted: 07/04/2019] [Indexed: 12/14/2022] Open
Abstract
The human genome is constantly exposed to both endogenous and exogenous stresses, which can lead to errors in DNA replication and the accumulation of DNA mutations, thereby increasing the risk of cancer development. The transcription factor E2F1 is a key regulator of DNA repair. E2F1 also has defined roles in the replication of many cell cycle-related genes and is highly expressed in cancer cells, and its abundance is strongly associated with poor prognosis in cancers. Studies on colon cancer have demonstrated that the depletion of E2F1 leads to reduced levels of homologous recombination (HR), resulting in interrupted DNA replication and the subsequent accumulation of DNA lesions. Our results demonstrate that the depletion of E2F1 also causes reduced RAD51-mediated DNA repair and diminished cell viability resulting from DNA damage. Furthermore, the extent of RAD51 and RPA colocalization is reduced in response to DNA damage; however, RPA single-stranded DNA (ssDNA) nucleofilament formation is not affected following the depletion of E2F1, implying that ssDNA gaps accumulate when RAD51-mediated DNA gap filling or repair is diminished. Surprisingly, we also demonstrate that E2F1 forms foci with RAD51 or RPA at DNA break sites on damaged DNA. These findings provide evidence of a molecular mechanism underlying the E2F1-mediated regulation of HR activity and predict a fundamental shift in the function of E2F1 from regulating cell division to accelerating tumor development.
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Affiliation(s)
- Eui-Hwan Choi
- Department of Life Sciences, Chung-Ang University, Seoul, 06974, South Korea
| | - Keun Pil Kim
- Department of Life Sciences, Chung-Ang University, Seoul, 06974, South Korea.
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13
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Warren NJH, Donahue KL, Eastman A. Differential Sensitivity to CDK2 Inhibition Discriminates the Molecular Mechanisms of CHK1 Inhibitors as Monotherapy or in Combination with the Topoisomerase I Inhibitor SN38. ACS Pharmacol Transl Sci 2019; 2:168-182. [PMID: 32259055 DOI: 10.1021/acsptsci.9b00001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Indexed: 02/06/2023]
Abstract
DNA damage activates checkpoints to arrest cell cycle progression in S and G2 phases, thereby providing time for repair and recovery. The combination of DNA-damaging agents and inhibitors of CHK1 (CHK1i) is an emerging strategy for sensitizing cancer cells. CHK1i induce replication on damaged DNA and mitosis before repair is complete, and this occurs in a majority of cell lines. However, ∼15% of cancer cell lines are hypersensitive to single-agent CHK1i. As both abrogation of S phase arrest and single-agent activity depend on CDK2, this study resolved how activation of CDK2 can be essential for both replication and cytotoxicity. S phase arrest was induced with the topoisomerase I inhibitor SN38; the addition of CHK1i rapidly activated CDK2, inducing S phase progression that was inhibited by the CDK2 inhibitor CVT-313. In contrast, DNA damage and cytotoxicity induced by single-agent CHK1i in hypersensitive cell lines were also inhibited by CVT-313 but at 20-fold lower concentrations. The differential sensitivity to CVT-313 is explained by different activity thresholds required for phosphorylation of CDK2 substrates. While the critical CDK2 substrates are not yet defined, we conclude that hypersensitivity to single-agent CHK1i depends on phosphorylation of substrates that require high CDK2 activity levels. Surprisingly, CHK1i did not increase SN38-mediated cytotoxicity. In contrast, while inhibition of WEE1 also abrogated S phase arrest, it more directly activated CDK1, induced premature mitosis, and enhanced cytotoxicity. Hence, while high activity of CDK2 is critical for cytotoxicity of single-agent CHK1i, CDK1 is additionally required for sensitivity to the drug combination.
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Affiliation(s)
- Nicholas J H Warren
- Geisel School of Medicine at Dartmouth and Norris Cotton Cancer Center, One Medical Center Drive, Lebanon, New Hampshire 03756, United States
| | - Katelyn L Donahue
- Geisel School of Medicine at Dartmouth and Norris Cotton Cancer Center, One Medical Center Drive, Lebanon, New Hampshire 03756, United States
| | - Alan Eastman
- Geisel School of Medicine at Dartmouth and Norris Cotton Cancer Center, One Medical Center Drive, Lebanon, New Hampshire 03756, United States
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14
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Ciardo D, Goldar A, Marheineke K. On the Interplay of the DNA Replication Program and the Intra-S Phase Checkpoint Pathway. Genes (Basel) 2019; 10:E94. [PMID: 30700024 PMCID: PMC6410103 DOI: 10.3390/genes10020094] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 01/23/2019] [Accepted: 01/25/2019] [Indexed: 12/12/2022] Open
Abstract
DNA replication in eukaryotes is achieved by the activation of multiple replication origins which needs to be precisely coordinated in space and time. This spatio-temporal replication program is regulated by many factors to maintain genome stability, which is frequently threatened through stresses of exogenous or endogenous origin. Intra-S phase checkpoints monitor the integrity of DNA synthesis and are activated when replication forks are stalled. Their activation leads to the stabilization of forks, to the delay of the replication program by the inhibition of late firing origins, and the delay of G2/M phase entry. In some cell cycles during early development these mechanisms are less efficient in order to allow rapid cell divisions. In this article, we will review our current knowledge of how the intra-S phase checkpoint regulates the replication program in budding yeast and metazoan models, including early embryos with rapid S phases. We sum up current models on how the checkpoint can inhibit origin firing in some genomic regions, but allow dormant origin activation in other regions. Finally, we discuss how numerical and theoretical models can be used to connect the multiple different actors into a global process and to extract general rules.
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Affiliation(s)
- Diletta Ciardo
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette CEDEX, France.
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15
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Sasi NK, Coquel F, Lin YL, MacKeigan JP, Pasero P, Weinreich M. DDK Has a Primary Role in Processing Stalled Replication Forks to Initiate Downstream Checkpoint Signaling. Neoplasia 2018; 20:985-995. [PMID: 30157471 PMCID: PMC6111017 DOI: 10.1016/j.neo.2018.08.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 08/01/2018] [Accepted: 08/02/2018] [Indexed: 02/05/2023]
Abstract
CDC7-DBF4 kinase (DDK) initiates DNA replication in eukaryotes by activating the replicative MCM helicase. DDK has diverse and apparently conflicting roles in the replication checkpoint response in various organisms, but the underlying mechanisms are far from settled. We show that human DDK promotes limited resection of newly synthesized DNA at stalled replication forks or sites of DNA damage to initiate replication checkpoint signaling. DDK is also required for efficient fork restart and G2/M cell cycle arrest. DDK exhibits genetic interactions with the ssDNA exonuclease EXO1 and phosphorylates EXO1 in vitro. EXO1 is also required for nascent strand degradation following exposure to HU, so DDK might regulate EXO1 directly. Lastly, sublethal DDK inhibition causes various mitotic abnormalities, which is consistent with a checkpoint deficiency. In summary, DDK has a primary and previously undescribed role in the replication checkpoint to promote ssDNA accumulation at stalled forks, which is required to initiate a robust checkpoint response and cell cycle arrest to maintain genome integrity.
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Affiliation(s)
- Nanda Kumar Sasi
- Laboratory of Genome Integrity and Tumorigenesis, Van Andel Research Institute (VARI), Grand Rapids, MI 49503; Laboratory of Systems Biology, VARI; Graduate Program in Genetics, Michigan State University, East Lansing, MI 48824
| | - Flavie Coquel
- IGH, Institute of Human Genetics CNRS UMR 9002 and University of Montpellier, Equipe Labellisée Ligue contre le Cancer, 141 rue de la Cardonille 34396 Cedex 5, Montpellier, France
| | - Yea-Lih Lin
- IGH, Institute of Human Genetics CNRS UMR 9002 and University of Montpellier, Equipe Labellisée Ligue contre le Cancer, 141 rue de la Cardonille 34396 Cedex 5, Montpellier, France
| | | | - Philippe Pasero
- IGH, Institute of Human Genetics CNRS UMR 9002 and University of Montpellier, Equipe Labellisée Ligue contre le Cancer, 141 rue de la Cardonille 34396 Cedex 5, Montpellier, France
| | - Michael Weinreich
- Laboratory of Genome Integrity and Tumorigenesis, Van Andel Research Institute (VARI), Grand Rapids, MI 49503.
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16
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Moiseeva TN, Bakkenist CJ. Regulation of the initiation of DNA replication in human cells. DNA Repair (Amst) 2018; 72:99-106. [PMID: 30266203 DOI: 10.1016/j.dnarep.2018.09.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 09/07/2018] [Indexed: 12/31/2022]
Abstract
The origin of species would not have been possible without high fidelity DNA replication and complex genomes evolved with mechanisms that control the initiation of DNA replication at multiple origins on multiple chromosomes such that the genome is duplicated once and only once. The mechanisms that control the assembly and activation of the replicative helicase and the initiation of DNA replication in yeast and Xenopus egg extract systems have been identified and reviewed [1,2]. The goal of this review is to organize currently available data on the mechanisms that control the initiation of DNA replication in human cells.
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Affiliation(s)
- Tatiana N Moiseeva
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Christopher J Bakkenist
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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17
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Shoaib M, Walter D, Gillespie PJ, Izard F, Fahrenkrog B, Lleres D, Lerdrup M, Johansen JV, Hansen K, Julien E, Blow JJ, Sørensen CS. Histone H4K20 methylation mediated chromatin compaction threshold ensures genome integrity by limiting DNA replication licensing. Nat Commun 2018; 9:3704. [PMID: 30209253 PMCID: PMC6135857 DOI: 10.1038/s41467-018-06066-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 08/09/2018] [Indexed: 11/20/2022] Open
Abstract
The decompaction and re-establishment of chromatin organization immediately after mitosis is essential for genome regulation. Mechanisms underlying chromatin structure control in daughter cells are not fully understood. Here we show that a chromatin compaction threshold in cells exiting mitosis ensures genome integrity by limiting replication licensing in G1 phase. Upon mitotic exit, chromatin relaxation is controlled by SET8-dependent methylation of histone H4 on lysine 20. In the absence of either SET8 or H4K20 residue, substantial genome-wide chromatin decompaction occurs allowing excessive loading of the origin recognition complex (ORC) in the daughter cells. ORC overloading stimulates aberrant recruitment of the MCM2-7 complex that promotes single-stranded DNA formation and DNA damage. Restoring chromatin compaction restrains excess replication licensing and loss of genome integrity. Our findings identify a cell cycle-specific mechanism whereby fine-tuned chromatin relaxation suppresses excessive detrimental replication licensing and maintains genome integrity at the cellular transition from mitosis to G1 phase.
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Affiliation(s)
- Muhammad Shoaib
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - David Walter
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Peter J Gillespie
- Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Fanny Izard
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, University of Montpellier, Institut Régional du Cancer (ICM), F-34298, Montpellier, France
| | - Birthe Fahrenkrog
- Institute for Molecular Biology and Medicine, Universite Libré de Bruxelles, Charleroi, 6041, Belgium
| | - David Lleres
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, 34293, France
| | - Mads Lerdrup
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Jens Vilstrup Johansen
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Klaus Hansen
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Eric Julien
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, University of Montpellier, Institut Régional du Cancer (ICM), F-34298, Montpellier, France
- Centre National de la Recherche Scientifique (CNRS), Montpellier, 34000, France
| | - J Julian Blow
- Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Claus S Sørensen
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark.
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18
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Jaafari-Ashkavandi Z, Tuyeh AA, Assar S. Immunohistochemical Expression of CDC7 in Dentigerous Cyst, Odontogenic Keratocyst and Radicular Cyst. ACTA MEDICA (HRADEC KRÁLOVÉ) 2018; 61:17-21. [PMID: 30012245 DOI: 10.14712/18059694.2018.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
CDC7 is a serine/threonine kinase which has an essential role in initiation of DNA proliferation and S phase. It increases the invasion and proliferation in many pathologic lesions. This study aimed to evaluate the expression of CDC7 in the most common odontogenic cysts. We evaluated 17 dentigerous cysts, 18 odontogenic keratocysts (OKC) and 13 radicular cysts immunohistochemically. The mean expression of CDC7 was analyzed using ANOVA and Post-HOC methods. All specimens revealed CDC7 expression. Higher expression of CDC7 in OKC and radicular cyst was shown in comparison to dentigerous cyst (P < 0.001), while radicular cyst and OKC groups showed no difference in CDC7 expression (P = 0.738). The high expression of CDC7 in OKC suggests that this protein could be related to the higher proliferation rate and invasiveness of OKC. On the other hand, the higher CDC7 expression in radicular cyst may simply be related to inflammation as this cyst is neither aggressive nor invasive.
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Affiliation(s)
- Zohreh Jaafari-Ashkavandi
- Department of Oral & Maxillofacial Pathology, Shiraz Dental School, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Sepideh Assar
- Department of Oral & Maxillofacial Pathology, Hormozgan Dental School, Hormozgan University of Medical Sciences, Hormozgan, Bandar-Abbas, Iran.
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19
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Makhouri FR, Ghasemi JB. High-throughput Docking and Molecular Dynamics Simulations towards the Identification of Novel Peptidomimetic Inhibitors against CDC7. Mol Inform 2018; 37:e1800022. [DOI: 10.1002/minf.201800022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 06/18/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Farahnaz Rezaei Makhouri
- Chemistry Department, Faculty of Sciences; K.N. Toosi University of Technology; Tehran 1969764499 Iran
| | - Jahan B. Ghasemi
- Chemistry Department, Faculty of Sciences; K.N. Toosi University of Technology; Tehran 1969764499 Iran
- Chemistry Department, Faculty of Sciences; University of Tehran; Tehran 1417466191 Iran
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20
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Li Q, Xie W, Wang N, Li C, Wang M. CDC7-dependent transcriptional regulation of RAD54L is essential for tumorigenicity and radio-resistance of glioblastoma. Transl Oncol 2018; 11:300-306. [PMID: 29413763 PMCID: PMC5884092 DOI: 10.1016/j.tranon.2018.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 12/26/2017] [Accepted: 01/03/2018] [Indexed: 01/05/2023] Open
Abstract
Accumulating evidence indicates that cell division cycle 7-related protein kinase(CDC7) plays an essential role in tumor cells and it could induces cell proliferation and could be related to prognosis in multiple types of cancer. However, the biological role and molecular mechanism of CDC7 in GBM still remains unclear. In this study, we identified that CDC7 expression was enriched in glioblastoma (GBM) tumors and was functionally required for tumor proliferation and its expression was associated to poor prognosis in GBM patients. Mechanically, CDC7 induced radio resistance in GBM cells and CDC7 knock down increased cell apoptosis when combined with radiotherapy. Moreover, CDC7 regulated The DNA repair/recombination protein 54L (RAD54L) expression via regulation of RAD54L promoter activity. Therapeutically, we found that CDC7 inhibitor attenuated tumor growth both in vitro and in vivo. Collectively, CDC7 promotes proliferation, induces radio resistance in GBM, and could become a potential therapeutic target for GBM.
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Affiliation(s)
- Qi Li
- Department of Neurosurgery, the First Affiliated Hospital of Xi'an Jiaotong University
| | - Wanfu Xie
- Department of Neurosurgery, the First Affiliated Hospital of Xi'an Jiaotong University
| | - Ning Wang
- Department of Neurosurgery, the First Affiliated Hospital of Xi'an Jiaotong University
| | - Chuankun Li
- Department of Neurosurgery, the First Affiliated Hospital of Xi'an Jiaotong University
| | - Maode Wang
- Department of Neurosurgery, the First Affiliated Hospital of Xi'an Jiaotong University.
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21
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Cdc7-Dbf4-mediated phosphorylation of HSP90-S164 stabilizes HSP90-HCLK2-MRN complex to enhance ATR/ATM signaling that overcomes replication stress in cancer. Sci Rep 2017; 7:17024. [PMID: 29209046 PMCID: PMC5717001 DOI: 10.1038/s41598-017-17126-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 10/09/2017] [Indexed: 12/31/2022] Open
Abstract
Cdc7-Dbf4 kinase plays a key role in the initiation of DNA replication and contributes to the replication stress in cancer. The activity of human Cdc7-Dbf4 kinase remains active and acts as an effector of checkpoint under replication stress. However, the downstream targets of Cdc7-Dbf4 contributed to checkpoint regulation and replication stress-support function in cancer are not fully identified. In this work, we showed that aberrant Cdc7-Dbf4 induces DNA lesions that activate ATM/ATR-mediated checkpoint and homologous recombination (HR) DNA repair. Using a phosphoproteome approach, we identified HSP90-S164 as a target of Cdc7-Dbf4 in vitro and in vivo. The phosphorylation of HSP90-S164 by Cdc7-Dbf4 is required for the stability of HSP90-HCLK2-MRN complex and the function of ATM/ATR signaling cascade and HR DNA repair. In clinically, the phosphorylation of HSP90-S164 indeed is increased in oral cancer patients. Our results indicate that aberrant Cdc7-Dbf4 enhances replication stress tolerance by rewiring ATR/ATM mediated HR repair through HSP90-S164 phosphorylation and by promoting recovery from replication stress. We provide a new solution to a subtyping of cancer patients with dominant ATR/HSP90 expression by combining inhibitors of ATR-Chk1, HSP90, or Cdc7 in cancer combination therapy.
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22
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Wu KZL, Wang GN, Fitzgerald J, Quachthithu H, Rainey MD, Cattaneo A, Bachi A, Santocanale C. DDK dependent regulation of TOP2A at centromeres revealed by a chemical genetics approach. Nucleic Acids Res 2016; 44:8786-8798. [PMID: 27407105 PMCID: PMC5062981 DOI: 10.1093/nar/gkw626] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 07/02/2016] [Indexed: 11/14/2022] Open
Abstract
In eukaryotic cells the CDC7/DBF4 kinase, also known as DBF4-dependent kinase (DDK), is required for the firing of DNA replication origins. CDC7 is also involved in replication stress responses and its depletion sensitises cells to drugs that affect fork progression, including Topoisomerase 2 poisons. Although CDC7 is an important regulator of cell division, relatively few substrates and bona-fide CDC7 phosphorylation sites have been identified to date in human cells. In this study, we have generated an active recombinant CDC7/DBF4 kinase that can utilize bulky ATP analogues. By performing in vitro kinase assays using benzyl-thio-ATP, we have identified TOP2A as a primary CDC7 substrate in nuclear extracts, and serine 1213 and serine 1525 as in vitro phosphorylation sites. We show that CDC7/DBF4 and TOP2A interact in cells, that this interaction mainly occurs early in S-phase, and that it is compromised after treatment with CDC7 inhibitors. We further provide evidence that human DBF4 localises at centromeres, to which TOP2A is progressively recruited during S-phase. Importantly, we found that CDC7/DBF4 down-regulation, as well S1213A/S1525A TOP2A mutations can advance the timing of centromeric TOP2A recruitment in S-phase. Our results indicate that TOP2A is a novel DDK target and have important implications for centromere biology.
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Affiliation(s)
- Kevin Z L Wu
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Guan-Nan Wang
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Jennifer Fitzgerald
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Huong Quachthithu
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Michael D Rainey
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Angela Cattaneo
- IFOM-FIRC Institute of Molecular Oncology, Milan 20139, Italy
| | - Angela Bachi
- IFOM-FIRC Institute of Molecular Oncology, Milan 20139, Italy
| | - Corrado Santocanale
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
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23
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Lee HS, Kundu J, Kim RN, Shin YK. Transducer of ERBB2.1 (TOB1) as a Tumor Suppressor: A Mechanistic Perspective. Int J Mol Sci 2015; 16:29815-28. [PMID: 26694352 PMCID: PMC4691146 DOI: 10.3390/ijms161226203] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 11/22/2015] [Accepted: 12/08/2015] [Indexed: 01/06/2023] Open
Abstract
Transducer of ERBB2.1 (TOB1) is a tumor-suppressor protein, which functions as a negative regulator of the receptor tyrosine-kinase ERBB2. As most of the other tumor suppressor proteins, TOB1 is inactivated in many human cancers. Homozygous deletion of TOB1 in mice is reported to be responsible for cancer development in the lung, liver, and lymph node, whereas the ectopic overexpression of TOB1 shows anti-proliferation, and a decrease in the migration and invasion abilities on cancer cells. Biochemical studies revealed that the anti-proliferative activity of TOB1 involves mRNA deadenylation and is associated with the reduction of both cyclin D1 and cyclin-dependent kinase (CDK) expressions and the induction of CDK inhibitors. Moreover, TOB1 interacts with an oncogenic signaling mediator, β-catenin, and inhibits β-catenin-regulated gene transcription. TOB1 antagonizes the v-akt murine thymoma viral oncogene (AKT) signaling and induces cancer cell apoptosis by activating BCL2-associated X (BAX) protein and inhibiting the BCL-2 and BCL-XL expressions. The tumor-specific overexpression of TOB1 results in the activation of other tumor suppressor proteins, such as mothers against decapentaplegic homolog 4 (SMAD4) and phosphatase and tensin homolog-10 (PTEN), and blocks tumor progression. TOB1-overexpressing cancer cells have limited potential of growing as xenograft tumors in nude mice upon subcutaneous implantation. This review addresses the molecular basis of TOB1 tumor suppressor function with special emphasis on its regulation of intracellular signaling pathways.
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Affiliation(s)
- Hun Seok Lee
- Research Institute of Pharmaceutical Science, Department of Pharmacy, College of Pharmacy, Seoul National University, Seoul 08826, Korea.
| | - Juthika Kundu
- Research Institute of Pharmaceutical Science, Department of Pharmacy, College of Pharmacy, Seoul National University, Seoul 08826, Korea.
| | - Ryong Nam Kim
- Research Institute of Pharmaceutical Science, Department of Pharmacy, College of Pharmacy, Seoul National University, Seoul 08826, Korea.
- Tumor Microenvironment Global Core Research Center, Seoul National University, Seoul 08826, Korea.
| | - Young Kee Shin
- Research Institute of Pharmaceutical Science, Department of Pharmacy, College of Pharmacy, Seoul National University, Seoul 08826, Korea.
- Tumor Microenvironment Global Core Research Center, Seoul National University, Seoul 08826, Korea.
- The Center for Anti-cancer Companion Diagnostics, School of Biological Science, Institutes of Entrepreneurial BioConvergence, Seoul National University, Seoul 08826, Korea.
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24
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PTEN Controls the DNA Replication Process through MCM2 in Response to Replicative Stress. Cell Rep 2015; 13:1295-1303. [DOI: 10.1016/j.celrep.2015.10.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 09/08/2015] [Accepted: 10/05/2015] [Indexed: 01/07/2023] Open
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25
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Yong-Deok K, Eun-Hyoung J, Yeon-Sun K, Kang-Mi P, Jin-Yong L, Sung-Hwan C, Tae-Yun K, Tae-Sung P, Soung-Min K, Myung-Jin K, Jong-Ho L. Molecular genetic study of novel biomarkers for early diagnosis of oral squamous cell carcinoma. Med Oral Patol Oral Cir Bucal 2015; 20:e167-79. [PMID: 25475780 PMCID: PMC4393979 DOI: 10.4317/medoral.20229] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 09/07/2014] [Indexed: 12/13/2022] Open
Abstract
Objectives: Early detection and treatment of an oral squamous cell carcinoma (OSCC) is critical because of its rapid growth, frequent lymph-node metastasis, and poor prognosis. However, no clinically-valuable methods of early diagnosis exist, and genetic analysis of OSCCs has yielded no biomarkers.
Study Design: We investigated the expression of genes associated with inflammation in OSCCs via a quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis of microarray data. Tumor and normal tissues from five patients with an OSCC were used for microarray analysis. Differentially-expressed genes, identified using permutation, local pooled error (LPE), t-tests, and significance analysis of microarrays (SAM), were selected as candidate genetic markers.
Results: Two groups corresponding to tissue identity were evident, implying that their differentially-expressed genes represented biological differences between tissues. Fifteen genes were identified using the Student’s paired t-test (p<0.05) and the SAM, with a false discovery rate of less than 0.02. Based on gene expression, these 15 genes can be used to classify an OSCC. A genetic analysis of functional networks and ontologies, validated by using a qRT-PCR analysis of the tissue samples, identified four genes, ADAM15, CDC7, IL12RB2 and TNFRSF8, that demonstrated excellent concordance with the microarray data.
Conclusions: Our study demonstrated that four genes (ADAM15, CDC7, IL12RB2 and TNFRSF8) had potential as novel biomarkers for the diagnosis and the treatment of an OSCC.
Key words:Biomarker, microarray, quantitative reverse transcription polymerase chain reaction, oral squamous cell carcinoma, gene expression profiling.
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Affiliation(s)
- Kim Yong-Deok
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Seoul National University, 275-1, Yeongeon-dong, Jongno-gu, Seoul, Republic of Korea,
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26
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Abrantes JLF, Tornatore TF, Pelizzaro-Rocha KJ, de Jesus MB, Cartaxo RT, Milani R, Ferreira-Halder CV. Crosstalk between kinases, phosphatases and miRNAs in cancer. Biochimie 2014; 107 Pt B:167-87. [PMID: 25230087 DOI: 10.1016/j.biochi.2014.09.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 09/04/2014] [Indexed: 02/07/2023]
Abstract
Reversible phosphorylation of proteins, performed by kinases and phosphatases, is the major post translational protein modification in eukaryotic cells. This intracellular event represents a critical regulatory mechanism of several signaling pathways and can be related to a vast array of diseases, including cancer. Cancer research has produced increasing evidence that kinase and phosphatase activity can be compromised by mutations and also by miRNA silencing, performed by small non-coding and endogenously produced RNA molecules that lead to translational repression. miRNAs are believed to target about one-third of human mRNAs while a single miRNA may target about 200 transcripts simultaneously. Regulation of the phosphorylation balance by miRNAs has been a topic of intense research over the last years, spanning topics going as far as cancer aggressiveness and chemotherapy resistance. By addressing recent studies that have shown miRNA expression patterns as phenotypic signatures of cancers and how miRNA influence cellular processes such as apoptosis, cell cycle control, angiogenesis, inflammation and DNA repair, we discuss how kinases, phosphatases and miRNAs cooperatively act in cancer biology.
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Affiliation(s)
- Júlia L F Abrantes
- Department of Biochemistry, Institute of Biology, UNICAMP, 13083-970 Campinas, Brazil
| | - Thaís F Tornatore
- Department of Biochemistry, Institute of Biology, UNICAMP, 13083-970 Campinas, Brazil
| | | | - Marcelo B de Jesus
- Department of Biochemistry, Institute of Biology, UNICAMP, 13083-970 Campinas, Brazil
| | - Rodrigo T Cartaxo
- Department of Biochemistry, Institute of Biology, UNICAMP, 13083-970 Campinas, Brazil
| | - Renato Milani
- Department of Biochemistry, Institute of Biology, UNICAMP, 13083-970 Campinas, Brazil
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Brandão LN, Ferguson R, Santoro I, Jinks-Robertson S, Sclafani RA. The role of Dbf4-dependent protein kinase in DNA polymerase ζ-dependent mutagenesis in Saccharomyces cerevisiae. Genetics 2014; 197:1111-22. [PMID: 24875188 PMCID: PMC4125387 DOI: 10.1534/genetics.114.165308] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 05/23/2014] [Indexed: 11/18/2022] Open
Abstract
The yeast Dbf4-dependent kinase (DDK) (composed of Dbf4 and Cdc7 subunits) is an essential, conserved Ser/Thr protein kinase that regulates multiple processes in the cell, including DNA replication, recombination and induced mutagenesis. Only DDK substrates important for replication and recombination have been identified. Consequently, the mechanism by which DDK regulates mutagenesis is unknown. The yeast mcm5-bob1 mutation that bypasses DDK's essential role in DNA replication was used here to examine whether loss of DDK affects spontaneous as well as induced mutagenesis. Using the sensitive lys2ΔA746 frameshift reversion assay, we show DDK is required to generate "complex" spontaneous mutations, which are a hallmark of the Polζ translesion synthesis DNA polymerase. DDK co-immunoprecipitated with the Rev7 regulatory, but not with the Rev3 polymerase subunit of Polζ. Conversely, Rev7 bound mainly to the Cdc7 kinase subunit and not to Dbf4. The Rev7 subunit of Polζ may be regulated by DDK phosphorylation as immunoprecipitates of yeast Cdc7 and also recombinant Xenopus DDK phosphorylated GST-Rev7 in vitro. In addition to promoting Polζ-dependent mutagenesis, DDK was also important for generating Polζ-independent large deletions that revert the lys2ΔA746 allele. The decrease in large deletions observed in the absence of DDK likely results from an increase in the rate of replication fork restart after an encounter with spontaneous DNA damage. Finally, nonepistatic, additive/synergistic UV sensitivity was observed in cdc7Δ pol32Δ and cdc7Δ pol30-K127R,K164R double mutants, suggesting that DDK may regulate Rev7 protein during postreplication "gap filling" rather than during "polymerase switching" by ubiquitinated and sumoylated modified Pol30 (PCNA) and Pol32.
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Affiliation(s)
- Luis N Brandão
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Rebecca Ferguson
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Irma Santoro
- Department of Biology, Emory University, Atlanta, Georgia 30322
| | - Sue Jinks-Robertson
- Department of Biology, Emory University, Atlanta, Georgia 30322 Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Robert A Sclafani
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045
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A high through-put screen for small molecules modulating MCM2 phosphorylation identifies Ryuvidine as an inducer of the DNA damage response. PLoS One 2014; 9:e98891. [PMID: 24902048 PMCID: PMC4047068 DOI: 10.1371/journal.pone.0098891] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 05/08/2014] [Indexed: 11/19/2022] Open
Abstract
DNA replication is an essential process for cell division and as such it is a process that is directly targeted by several anticancer drugs. CDC7 plays an essential role in the activation of replication origins and has recently been proposed as a novel target for drug discovery. The MCM DNA helicase complex (MCM2-7) is a key target of the CDC7 kinase, and MCM phosphorylation status at specific sites is a reliable biomarker of CDC7 cellular activity. In this work we describe a cell-based assay that utilizes the "In Cell Western Technique" (ICW) to identify compounds that affect cellular CDC7 activity. By screening a library of approved drugs and kinase inhibitors we found several compounds that can affect CDC7-dependent phosphorylation of MCM2 in HeLa cells. Among these, Mitoxantrone, a topoisomerase inhibitor, and Ryuvidine, previously described as a CDK4 inhibitor, cause a reduction in phosphorylated MCM2 levels and a sudden blockade of DNA synthesis that is accompanied by an ATM-dependent checkpoint response. This study sheds light on the previously observed cytotoxity of Ryuvidine, strongly suggesting that it is related to its effect of causing DNA damage.
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29
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Yamada M, Masai H, Bartek J. Regulation and roles of Cdc7 kinase under replication stress. Cell Cycle 2014; 13:1859-66. [PMID: 24841992 DOI: 10.4161/cc.29251] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Cdc7 (cell division cycle 7) kinase together with its activation subunit ASK (also known as Dbf4) play pivotal roles in DNA replication and contribute also to other aspects of DNA metabolism such as DNA repair and recombination. While the biological significance of Cdc7 is widely appreciated, the molecular mechanisms through which Cdc7 kinase regulates these various DNA transactions remain largely obscure, including the role of Cdc7-ASK/Dbf4 under replication stress, a condition associated with diverse (patho)physiological scenarios. In this review, we first highlight the recent findings on a novel pathway that regulates the stability of the human Cdc7-ASK/Dbf4 complex under replication stress, its interplay with ATR-Chk1 signaling, and significance in the RAD18-dependent DNA damage bypass pathway. We also consider Cdc7 function in a broader context, considering both physiological conditions and pathologies associated with enhanced replication stress, particularly oncogenic transformation and tumorigenesis. Furthermore, we integrate the emerging evidence and propose a concept of Cdc7-ASK/Dbf4 contributing to genome integrity maintenance, through interplay with RAD18 that can serve as a molecular switch to dictate DNA repair pathway choice. Finally, we discuss the possibility of targeting Cdc7, particularly in the context of the Cdc7/RAD18-dependent translesion synthesis, as a potential innovative strategy for treatment of cancer.
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Affiliation(s)
- Masayuki Yamada
- Institute of Molecular and Translational Medicine; Faculty of Medicine and Dentistry; Palacky University; Olomouc, Czech Republic
| | - Hisao Masai
- Genome Dynamics Project; Department of Genome Medicine; Tokyo Metropolitan Institute of Medical Science; Tokyo, Japan
| | - Jiri Bartek
- Institute of Molecular and Translational Medicine; Faculty of Medicine and Dentistry; Palacky University; Olomouc, Czech Republic; Danish Cancer Society Research Center; Copenhagen, Denmark
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30
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Poh WT, Chadha GS, Gillespie PJ, Kaldis P, Blow JJ. Xenopus Cdc7 executes its essential function early in S phase and is counteracted by checkpoint-regulated protein phosphatase 1. Open Biol 2014; 4:130138. [PMID: 24403013 PMCID: PMC3909274 DOI: 10.1098/rsob.130138] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 12/03/2013] [Indexed: 01/31/2023] Open
Abstract
The initiation of DNA replication requires two protein kinases: cyclin-dependent kinase (Cdk) and Cdc7. Although S phase Cdk activity has been intensively studied, relatively little is known about how Cdc7 regulates progression through S phase. We have used a Cdc7 inhibitor, PHA-767491, to dissect the role of Cdc7 in Xenopus egg extracts. We show that hyperphosphorylation of mini-chromosome maintenance (MCM) proteins by Cdc7 is required for the initiation, but not for the elongation, of replication forks. Unlike Cdks, we demonstrate that Cdc7 executes its essential functions by phosphorylating MCM proteins at virtually all replication origins early in S phase and is not limiting for progression through the Xenopus replication timing programme. We demonstrate that protein phosphatase 1 (PP1) is recruited to chromatin and rapidly reverses Cdc7-mediated MCM hyperphosphorylation. Checkpoint kinases induced by DNA damage or replication inhibition promote the association of PP1 with chromatin and increase the rate of MCM dephosphorylation, thereby counteracting the previously completed Cdc7 functions and inhibiting replication initiation. This novel mechanism for regulating Cdc7 function provides an explanation for previous contradictory results concerning the control of Cdc7 by checkpoint kinases and has implications for the use of Cdc7 inhibitors as anti-cancer agents.
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Affiliation(s)
- Wei Theng Poh
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dow St., Dundee DD1 5EH, UK
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research (A*STAR), Singapore 138673, Republic of Singapore
| | - Gaganmeet Singh Chadha
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dow St., Dundee DD1 5EH, UK
| | - Peter J. Gillespie
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dow St., Dundee DD1 5EH, UK
| | - Philipp Kaldis
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research (A*STAR), Singapore 138673, Republic of Singapore
| | - J. Julian Blow
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dow St., Dundee DD1 5EH, UK
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Yamada M, Watanabe K, Mistrik M, Vesela E, Protivankova I, Mailand N, Lee M, Masai H, Lukas J, Bartek J. ATR-Chk1-APC/CCdh1-dependent stabilization of Cdc7-ASK (Dbf4) kinase is required for DNA lesion bypass under replication stress. Genes Dev 2014; 27:2459-72. [PMID: 24240236 PMCID: PMC3841735 DOI: 10.1101/gad.224568.113] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cdc7 kinase regulates DNA replication. However, its role in DNA repair and recombination is poorly understood. Here we describe a pathway that stabilizes the human Cdc7-ASK (activator of S-phase kinase; also called Dbf4), its regulation, and its function in cellular responses to compromised DNA replication. Stalled DNA replication evoked stabilization of the Cdc7-ASK (Dbf4) complex in a manner dependent on ATR-Chk1-mediated checkpoint signaling and its interplay with the anaphase-promoting complex/cyclosome(Cdh1) (APC/C(Cdh1)) ubiquitin ligase. Mechanistically, Chk1 kinase inactivates APC/C(Cdh1) through degradation of Cdh1 upon replication block, thereby stabilizing APC/C(Cdh1) substrates, including Cdc7-ASK (Dbf4). Furthermore, motif C of ASK (Dbf4) interacts with the N-terminal region of RAD18 ubiquitin ligase, and this interaction is required for chromatin binding of RAD18. Impaired interaction of ASK (Dbf4) with RAD18 disables foci formation by RAD18 and hinders chromatin loading of translesion DNA polymerase η. These findings define a novel mechanism that orchestrates replication checkpoint signaling and ubiquitin-proteasome machinery with the DNA damage bypass pathway to guard against replication collapse under conditions of replication stress.
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Affiliation(s)
- Masayuki Yamada
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, CZ-775 15 Olomouc, Czech Republic
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Replication checkpoint: tuning and coordination of replication forks in s phase. Genes (Basel) 2013; 4:388-434. [PMID: 24705211 PMCID: PMC3924824 DOI: 10.3390/genes4030388] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/30/2013] [Accepted: 08/02/2013] [Indexed: 12/01/2022] Open
Abstract
Checkpoints monitor critical cell cycle events such as chromosome duplication and segregation. They are highly conserved mechanisms that prevent progression into the next phase of the cell cycle when cells are unable to accomplish the previous event properly. During S phase, cells also provide a surveillance mechanism called the DNA replication checkpoint, which consists of a conserved kinase cascade that is provoked by insults that block or slow down replication forks. The DNA replication checkpoint is crucial for maintaining genome stability, because replication forks become vulnerable to collapse when they encounter obstacles such as nucleotide adducts, nicks, RNA-DNA hybrids, or stable protein-DNA complexes. These can be exogenously induced or can arise from endogenous cellular activity. Here, we summarize the initiation and transduction of the replication checkpoint as well as its targets, which coordinate cell cycle events and DNA replication fork stability.
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33
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Barkley LR, Santocanale C. MicroRNA-29a regulates the benzo[a]pyrene dihydrodiol epoxide-induced DNA damage response through Cdc7 kinase in lung cancer cells. Oncogenesis 2013; 2:e57. [PMID: 23877787 PMCID: PMC3740286 DOI: 10.1038/oncsis.2013.20] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 06/08/2013] [Accepted: 06/10/2013] [Indexed: 12/11/2022] Open
Abstract
Cdc7 kinase is a key regulator of DNA replication and has an important role in the cellular DNA damage response by controlling checkpoint signaling and cell survival. Yet, how the activity of Cdc7 kinase is regulated is poorly understood. In silico analysis identified microRNA-29 (miR-29)-binding sites in the 3'-untranslated region (UTR) of both Cdc7 and its activating subunit Dbf4. We show that miR-29a binds to Cdc7 and Dbf4 3'-UTRs and regulates kinase levels. We find that in response to DNA damage, upregulation of Cdc7 kinase correlates with a downregulation in miR-29a. Enforced miR-29a expression prevents the accumulation of Cdc7 in response to the environmental genotoxin, benzo[a]pyrene dihydrodiol epoxide (BPDE) present in cigarette smoke, resulting in aberrant checkpoint signaling and increased cell lethality. As BPDE sensitivity was rescued by overexpression of miRNA-resistant Cdc7/Dbf4, we propose that Cdc7 kinase is an important target of miR-29a in determining cell survival from genotoxic stress caused by this environmental toxin.
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Affiliation(s)
- L R Barkley
- Centre for Chromosome Biology and National Centre for Biomedical Engineering Science, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
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34
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Rainey MD, Harhen B, Wang GN, Murphy PV, Santocanale C. Cdc7-dependent and -independent phosphorylation of Claspin in the induction of the DNA replication checkpoint. Cell Cycle 2013; 12:1560-8. [PMID: 23598722 DOI: 10.4161/cc.24675] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Claspin is a critical mediator protein in the DNA replication checkpoint, responsible for ATR-dependent activation of the effector kinase Chk1. Cdc7, an essential kinase required for the initiation of DNA replication, can also interact with and phosphorylate Claspin. In this study we use small-molecule inhibitors of Cdc7 kinase to further understand the relationship between Cdc7, Claspin and Chk1 activation. We demonstrate that inhibition of Cdc7 kinase delays HU-induced phosphorylation of Chk1 but does not affect the maintenance of the replication checkpoint once it is established. We find that while chromatin association of Claspin is not affected by Cdc7 inhibition, Claspin phosphorylation is attenuated following HU treatment, which may be responsible for the altered kinetics of HU-induced Chk1 phosphorylation. We demonstrate that Claspin is an in vitro substrate of Cdc7 kinase, and using mass-spectrometry, we identify multiple phosphorylation sites that help to define a Cdc7 phosphorylation motif. Finally, we show that the interaction between Claspin and Cdc7 is not dependent on Cdc7 kinase activity, but Claspin interaction with the DNA helicase subunit Mcm2 is lost upon Cdc7 inhibition. We propose Cdc7-dependent phosphorylation regulates critical protein-protein interactions and modulates Claspin's function in the DNA replication checkpoint.
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Affiliation(s)
- Michael D Rainey
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
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35
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Suzuki T, Tsuzuku J, Hayashi A, Shiomi Y, Iwanari H, Mochizuki Y, Hamakubo T, Kodama T, Nishitani H, Masai H, Yamamoto T. Inhibition of DNA damage-induced apoptosis through Cdc7-mediated stabilization of Tob. J Biol Chem 2012; 287:40256-65. [PMID: 23066029 DOI: 10.1074/jbc.m112.353805] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Preventing unnecessary cell death is essential for DNA-damaged cells to carry out the DNA repair process. RESULTS Cdc7 inhibits the Cul4-DDB1(Cdt2)-dependent Tob degradation. CONCLUSION Cdc7 enables mild DNA-damaged cells to keep their viability by competing with the Tob degradation system. SIGNIFICANCE Cells deal with moderate DNA damage not only by cessation of the cell cycle but also through direct mediated pro-survival signaling. Cells respond to DNA damage by activating alternate signaling pathways that induce proliferation arrest or apoptosis. The correct balance between these two pathways is important for maintaining genomic integrity and preventing unnecessary cell death. The mechanism by which DNA-damaged cells escape from apoptosis during DNA repair is poorly understood. We show that the DNA replication-initiating kinase Cdc7 actively prevents unnecessary death in DNA-damaged cells. In response to mild DNA damage, Tob levels increase through both a transcriptional mechanism and protein stabilization, resulting in inhibition of pro-apoptotic signaling. Cells lacking Cdc7 expression undergo apoptosis after mild DNA damage, where Cul4-DDB1(Cdt2) induces Tob ubiquitination and subsequent degradation. Cdc7 phosphorylates and interacts with Tob to inhibit the Cul4-DDB1(Cdt2)-dependent Tob degradation. Thus, Cdc7 defines an essential pro-survival signaling pathway by contributing to stabilization of Tob, thereby the viability of DNA-damaged cells being maintained.
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Affiliation(s)
- Toru Suzuki
- Department of Cancer Biology, Division of Oncology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Tokyo 108-8639, Japan
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Abe S, Kurata M, Suzuki S, Yamamoto K, Aisaki KI, Kanno J, Kitagawa M. Minichromosome maintenance 2 bound with retroviral Gp70 is localized to cytoplasm and enhances DNA-damage-induced apoptosis. PLoS One 2012; 7:e40129. [PMID: 22768239 PMCID: PMC3387003 DOI: 10.1371/journal.pone.0040129] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 06/01/2012] [Indexed: 11/19/2022] Open
Abstract
The interaction of viral proteins with host-cellular proteins elicits the activation of cellular signal transduction pathways and possibly leads to viral pathogenesis as well as cellular biological events. Apoptotic signals induced by DNA-damage are remarkably up-regulated by Friend leukemia virus (FLV) exclusively in C3H hosts; however, the mechanisms underlying the apoptosis enhancement and host-specificity are unknown. Here, we show that C3H mouse-derived hematopoietic cells originally express higher levels of the minichromosome maintenance (MCM) 2 protein than BALB/c- or C57BL/6-deriverd cells, and undergo more frequent apoptosis following doxorubicin-induced DNA-damage in the presence of the FLV envelope protein gp70. Dual transfection with gp70/Mcm2 reproduced doxorubicin-induced apoptosis even in BALB/c-derived 3T3 cells. Immunoprecipitation assays using various deletion mutants of MCM2 revealed that gp70 bound to the nuclear localization signal (NLS) 1 (amino acids 18–24) of MCM2, interfered with the function of NLS2 (amino acids 132–152), and suppressed the normal nuclear-import of MCM2. Cytoplasmic MCM2 reduced the activity of protein phosphatase 2A (PP2A) leading to the subsequent hyperphosphorylation of DNA-dependent protein kinase (DNA-PK). Phosphorylated DNA-PK exhibited elevated kinase activity to phosphorylate P53, thereby up-regulating p53-dependent apoptosis. An apoptosis-enhancing domain was identified in the C-terminal portion (amino acids 703–904) of MCM2. Furthermore, simultaneous treatment with FLV and doxorubicin extended the survival of SCID mice bearing 8047 leukemia cells expressing high levels of MCM2. Thus, depending on its subcellular localization, MCM2 plays different roles. It participates in DNA replication in the nucleus as shown previously, and enhances apoptosis in the cytoplasm.
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Affiliation(s)
- Shinya Abe
- Department of Comprehensive Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Morito Kurata
- Department of Comprehensive Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shiho Suzuki
- Department of Comprehensive Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kouhei Yamamoto
- Department of Comprehensive Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Ken-ichi Aisaki
- Division of Cellular and Molecular Toxicology, National Institute of Health Sciences, Tokyo, Japan
| | - Jun Kanno
- Division of Cellular and Molecular Toxicology, National Institute of Health Sciences, Tokyo, Japan
| | - Masanobu Kitagawa
- Department of Comprehensive Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
- * E-mail:
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37
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Ito S, Ishii A, Kakusho N, Taniyama C, Yamazaki S, Fukatsu R, Sakaue-Sawano A, Miyawaki A, Masai H. Mechanism of cancer cell death induced by depletion of an essential replication regulator. PLoS One 2012; 7:e36372. [PMID: 22574151 PMCID: PMC3344859 DOI: 10.1371/journal.pone.0036372] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 03/30/2012] [Indexed: 01/17/2023] Open
Abstract
Background Depletion of replication factors often causes cell death in cancer cells. Depletion of Cdc7, a kinase essential for initiation of DNA replication, induces cancer cell death regardless of its p53 status, but the precise pathways of cell death induction have not been characterized. Methodology/Principal Findings We have used the recently-developed cell cycle indicator, Fucci, to precisely characterize the cell death process induced by Cdc7 depletion. We have also generated and utilized similar fluorescent cell cycle indicators using fusion with other cell cycle regulators to analyze modes of cell death in live cells in both p53-positive and -negative backgrounds. We show that distinct cell-cycle responses are induced in p53-positive and -negative cells by Cdc7 depletion. p53-negative cells predominantly arrest temporally in G2-phase, accumulating CyclinB1 and other mitotic regulators. Prolonged arrest at G2-phase and abrupt entry into aberrant M-phase in the presence of accumulated CyclinB1 are followed by cell death at the post-mitotic state. Abrogation of cytoplasmic CyclinB1 accumulation partially decreases cell death. The ATR-MK2 pathway is responsible for sequestration of CyclinB1 with 14-3-3σ protein. In contrast, p53-positive cancer cells do not accumulate CyclinB1, but appear to die mostly through entry into aberrant S-phase after Cdc7 depletion. The combination of Cdc7 inhibition with known anti-cancer agents significantly stimulates cell death effects in cancer cells in a genotype-dependent manner, providing a strategic basis for future combination therapies. Conclusions Our results show that the use of Fucci, and similar fluorescent cell cycle indicators, offers a convenient assay system with which to identify cell cycle events associated with cancer cell death. They also indicate genotype-specific cell death modes induced by deficient initiation of DNA replication in cancer cells and its potential exploitation for development of efficient cancer therapies.
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Affiliation(s)
- Sayuri Ito
- Genome Dynamics Project, Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, Japan
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Interactions of the human MCM-BP protein with MCM complex components and Dbf4. PLoS One 2012; 7:e35931. [PMID: 22540012 PMCID: PMC3335088 DOI: 10.1371/journal.pone.0035931] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 03/27/2012] [Indexed: 12/22/2022] Open
Abstract
MCM-BP was discovered as a protein that co-purified from human cells with MCM proteins 3 through 7; results which were recapitulated in frogs, yeast and plants. Evidence in all of these organisms supports an important role for MCM-BP in DNA replication, including contributions to MCM complex unloading. However the mechanisms by which MCM-BP functions and associates with MCM complexes are not well understood. Here we show that human MCM-BP is capable of interacting with individual MCM proteins 2 through 7 when co-expressed in insect cells and can greatly increase the recovery of some recombinant MCM proteins. Glycerol gradient sedimentation analysis indicated that MCM-BP interacts most strongly with MCM4 and MCM7. Similar gradient analyses of human cell lysates showed that only a small amount of MCM-BP overlapped with the migration of MCM complexes and that MCM complexes were disrupted by exogenous MCM-BP. In addition, large complexes containing MCM-BP and MCM proteins were detected at mid to late S phase, suggesting that the formation of specific MCM-BP complexes is cell cycle regulated. We also identified an interaction between MCM-BP and the Dbf4 regulatory component of the DDK kinase in both yeast 2-hybrid and insect cell co-expression assays, and this interaction was verified by co-immunoprecipitation of endogenous proteins from human cells. In vitro kinase assays showed that MCM-BP was not a substrate for DDK but could inhibit DDK phosphorylation of MCM4,6,7 within MCM4,6,7 or MCM2-7 complexes, with little effect on DDK phosphorylation of MCM2. Since DDK is known to activate DNA replication through phosphorylation of these MCM proteins, our results suggest that MCM-BP may affect DNA replication in part by regulating MCM phosphorylation by DDK.
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39
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Lee AYL, Chiba T, Truong LN, Cheng AN, Do J, Cho MJ, Chen L, Wu X. Dbf4 is direct downstream target of ataxia telangiectasia mutated (ATM) and ataxia telangiectasia and Rad3-related (ATR) protein to regulate intra-S-phase checkpoint. J Biol Chem 2011; 287:2531-43. [PMID: 22123827 DOI: 10.1074/jbc.m111.291104] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dbf4/Cdc7 (Dbf4-dependent kinase (DDK)) is activated at the onset of S-phase, and its kinase activity is required for DNA replication initiation from each origin. We showed that DDK is an important target for the S-phase checkpoint in mammalian cells to suppress replication initiation and to protect replication forks. We demonstrated that ataxia telangiectasia mutated (ATM) and ataxia telangiectasia and Rad3-related (ATR) proteins directly phosphorylate Dbf4 in response to ionizing radiation and replication stress. We identified novel ATM/ATR phosphorylation sites on Dbf4 and showed that ATM/ATR-mediated phosphorylation of Dbf4 is critical for the intra-S-phase checkpoint to inhibit DNA replication. The kinase activity of DDK, which is not suppressed upon DNA damage, is required for fork protection under replication stress. We further demonstrated that ATM/ATR-mediated phosphorylation of Dbf4 is important for preventing DNA rereplication upon loss of replication licensing through the activation of the S-phase checkpoint. These studies indicate that DDK is a direct substrate of ATM and ATR to mediate the intra-S-phase checkpoint in mammalian cells.
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Affiliation(s)
- Alan Yueh-Luen Lee
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA.
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Méndez J. Cyclin E goes nuts: a cell cycle regulator affects male fertility. Cell Cycle 2011; 9:4782. [PMID: 21248485 DOI: 10.4161/cc.9.24.14060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Vogiatzi P, Mason PJ. Research highlights on a notable retrovirus and a popular guardian gene. Cell Cycle 2010; 9:4786. [PMID: 21248483 DOI: 10.4161/cc.9.24.14166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Day TA, Palle K, Barkley LR, Kakusho N, Zou Y, Tateishi S, Verreault A, Masai H, Vaziri C. Phosphorylated Rad18 directs DNA polymerase η to sites of stalled replication. ACTA ACUST UNITED AC 2010; 191:953-66. [PMID: 21098111 PMCID: PMC2995173 DOI: 10.1083/jcb.201006043] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cdc7 phosphorylates Rad18 to integrate S phase progression with postreplication DNA repair, ensuring genome stability. The E3 ubiquitin ligase Rad18 guides DNA Polymerase eta (Polη) to sites of replication fork stalling and mono-ubiquitinates proliferating cell nuclear antigen (PCNA) to facilitate binding of Y family trans-lesion synthesis (TLS) DNA polymerases during TLS. However, it is unclear exactly how Rad18 is regulated in response to DNA damage and how Rad18 activity is coordinated with progression through different phases of the cell cycle. Here we identify Rad18 as a novel substrate of the essential protein kinase Cdc7 (also termed Dbf4/Drf1-dependent Cdc7 kinase [DDK]). A serine cluster in the Polη-binding motif of Rad18 is phosphorylated by DDK. Efficient association of Rad18 with Polη is dependent on DDK and is necessary for redistribution of Polη to sites of replication fork stalling. This is the first demonstration of Rad18 regulation by direct phosphorylation and provides a novel mechanism for integration of S phase progression with postreplication DNA repair to maintain genome stability.
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Affiliation(s)
- Tovah A Day
- Department of Genetics and Genomics and 2 Center for Human Genetics, Boston University School of Medicine, Boston, MA 02118, USA
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43
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Chk1 promotes replication fork progression by controlling replication initiation. Proc Natl Acad Sci U S A 2010; 107:16090-5. [PMID: 20805465 DOI: 10.1073/pnas.1005031107] [Citation(s) in RCA: 217] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
DNA replication starts at initiation sites termed replication origins. Metazoan cells contain many more potential origins than are activated (fired) during each S phase. Origin activation is controlled by the ATR checkpoint kinase and its downstream effector kinase Chk1, which suppresses origin firing in response to replication blocks and during normal S phase by inhibiting the cyclin-dependent kinase Cdk2. In addition to increased origin activation, cells deficient in Chk1 activity display reduced rates of replication fork progression. Here we investigate the causal relationship between increased origin firing and reduced replication fork progression. We use the Cdk inhibitor roscovitine or RNAi depletion of Cdc7 to inhibit origin firing in Chk1-inhibited or RNAi-depleted cells. We report that Cdk inhibition and depletion of Cdc7 can alleviate the slow replication fork speeds in Chk1-deficient cells. Our data suggest that increased replication initiation leads to slow replication fork progression and that Chk1 promotes replication fork progression during normal S phase by controlling replication origin activity.
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Molecular architecture of the DNA replication origin activation checkpoint. EMBO J 2010; 29:3381-94. [PMID: 20729811 DOI: 10.1038/emboj.2010.201] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 07/27/2010] [Indexed: 12/13/2022] Open
Abstract
Perturbation of DNA replication initiation arrests human cells in G1, pointing towards an origin activation checkpoint. We used RNAi against Cdc7 kinase to inhibit replication initiation and dissect this checkpoint in fibroblasts. We show that the checkpoint response is dependent on three axes coordinated through the transcription factor FoxO3a. In arrested cells, FoxO3a activates the ARF-∣Hdm2-∣p53 → p21 pathway and mediates p15(INK4B) upregulation; p53 in turn activates expression of the Wnt/β-catenin signalling antagonist Dkk3, leading to Myc and cyclin D1 downregulation. The resulting loss of CDK activity inactivates the Rb-E2F pathway and overrides the G1-S transcriptional programme. Fibroblasts concomitantly depleted of Cdc7/FoxO3a, Cdc7/p15, Cdc7/p53 or Cdc7/Dkk3 can bypass the arrest and proceed into an abortive S phase followed by apoptosis. The lack of redundancy between the checkpoint axes and reliance on several tumour suppressor proteins commonly inactivated in human tumours provides a mechanistic basis for the cancer-cell-specific killing observed with emerging Cdc7 inhibitors.
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Montagnoli A, Moll J, Colotta F. Targeting cell division cycle 7 kinase: a new approach for cancer therapy. Clin Cancer Res 2010; 16:4503-8. [PMID: 20647475 DOI: 10.1158/1078-0432.ccr-10-0185] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The cell division cycle 7 (Cdc7) is a serine-threonine kinase, originally discovered in budding yeast, required to initiate DNA replication. Human Cdc7 phosphorylates the minichromosome maintenance protein 2 (Mcm2), a component of the DNA replicative helicase needed for genome duplication. Inhibition of Cdc7 in cancer cells impairs progression through S phase, inducing a p53-independent apoptotic cell death, whereas in normal cells, it does not affect cell viability. Small molecule compounds able to interfere with Cdc7 activity have been identified and shown to be effective in controlling tumor growth in animal models. Two Cdc7 inhibitors are currently in phase I clinical development. Inhibition of Cdc7 kinase activity in cancer cells restricts DNA replication and induces apoptotic cell death by an unprecedented molecular mechanism of action.
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Masai H, Matsumoto S, You Z, Yoshizawa-Sugata N, Oda M. Eukaryotic chromosome DNA replication: where, when, and how? Annu Rev Biochem 2010; 79:89-130. [PMID: 20373915 DOI: 10.1146/annurev.biochem.052308.103205] [Citation(s) in RCA: 370] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
DNA replication is central to cell proliferation. Studies in the past six decades since the proposal of a semiconservative mode of DNA replication have confirmed the high degree of conservation of the basic machinery of DNA replication from prokaryotes to eukaryotes. However, the need for replication of a substantially longer segment of DNA in coordination with various internal and external signals in eukaryotic cells has led to more complex and versatile regulatory strategies. The replication program in higher eukaryotes is under a dynamic and plastic regulation within a single cell, or within the cell population, or during development. We review here various regulatory mechanisms that control the replication program in eukaryotes and discuss future directions in this dynamic field.
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Affiliation(s)
- Hisao Masai
- Genome Dynamics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan.
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Gold DA, Dunphy WG. Drf1-dependent kinase interacts with Claspin through a conserved protein motif. J Biol Chem 2010; 285:12638-46. [PMID: 20190277 DOI: 10.1074/jbc.m109.077370] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The Dbf4/Drf1-dependent kinase (DDK) is required for the initiation of DNA replication in eukaryotes. Another protein, Claspin, mediates the activation of a cellular checkpoint response to stalled replication forks and is also a regulator of replication. In this study, we found that DDK phosphorylates Claspin in vitro and forms a nuclear complex containing Cdc7, Drf1, and Claspin in Xenopus egg extracts. In addition, purified Claspin and DDK are capable of a direct in vitro interaction. We identified a conserved binding site on Claspin required for its interaction with DDK. This site corresponds to the first of two sequence repeats in the Chk1-binding domain of Claspin. Furthermore, we have established that two amino acids in this motif, Asp(861) and Gln(866), are essential for the interaction between Claspin and DDK. We found that mutant forms of Claspin incapable of interacting with DDK are still able to associate with and activate Chk1 in response to DNA replication blockages. However, Claspin-depleted egg extracts that have been reconstituted with these mutants of Claspin undergo DNA replication more slowly. These findings suggest that the interaction of DDK with Claspin mediates a checkpoint-independent function of Claspin related to DNA replication.
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Affiliation(s)
- Daniel A Gold
- Division of Biology, California Institute of Technology, Pasadena, California 91125, USA
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Swords R, Mahalingam D, O’Dwyer M, Santocanale C, Kelly K, Carew J, Giles F. Cdc7 kinase – A new target for drug development. Eur J Cancer 2010; 46:33-40. [DOI: 10.1016/j.ejca.2009.09.020] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 08/14/2009] [Accepted: 09/17/2009] [Indexed: 02/03/2023]
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Kaufmann WK. The human intra-S checkpoint response to UVC-induced DNA damage. Carcinogenesis 2009; 31:751-65. [PMID: 19793801 DOI: 10.1093/carcin/bgp230] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The intra-S checkpoint response to 254 nm light (UVC)-induced DNA damage appears to have dual functions to slow the rate of DNA synthesis and stabilize replication forks that become stalled at sites of UVC-induced photoproducts in DNA. These functions should provide more time for repair of damaged DNA before its replication and thereby reduce the frequencies of mutations and chromosomal aberrations in surviving cells. This review tries to summarize the history of discovery of the checkpoint, the current state of understanding of the biological features of intra-S checkpoint signaling and its mechanisms of action with a focus primarily on intra-S checkpoint responses in human cells. The differences in the intra-S checkpoint responses to UVC and ionizing radiation-induced DNA damage are emphasized. Evidence that [6-4]pyrimidine-pyrimidone photoproducts in DNA trigger the response is discussed and the relationships between cellular responses to UVC and the molecular dose of UVC-induced DNA damage are briefly summarized. The role of the intra-S checkpoint response in protecting against solar radiation carcinogenesis remains to be determined.
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Affiliation(s)
- William K Kaufmann
- Department of Pathology and Laboratory Medicine, Center for Environmental Health and Susceptibility, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7295, USA.
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Bivi N, Romanello M, Harrison R, Clarke I, Hoyle DC, Moro L, Ortolani F, Bonetti A, Quadrifoglio F, Tell G, Delneri D. Identification of secondary targets of N-containing bisphosphonates in mammalian cells via parallel competition analysis of the barcoded yeast deletion collection. Genome Biol 2009; 10:R93. [PMID: 19744312 PMCID: PMC2768982 DOI: 10.1186/gb-2009-10-9-r93] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 07/16/2009] [Accepted: 09/10/2009] [Indexed: 11/10/2022] Open
Abstract
Growth competition assays using barcoded yeast deletion-mutants reveal the molecular targets of nitrogen containing bisphosphonates used for the treatment of bone cancers and osteoporosis. Background Nitrogen-containing bisphosphonates are the elected drugs for the treatment of diseases in which excessive bone resorption occurs, for example, osteoporosis and cancer-induced bone diseases. The only known target of nitrogen-containing bisphosphonates is farnesyl pyrophosphate synthase, which ensures prenylation of prosurvival proteins, such as Ras. However, it is likely that the action of nitrogen-containing bisphosphonates involves additional unknown mechanisms. To identify novel targets of nitrogen-containing bisphosphonates, we used a genome-wide high-throughput screening in which 5,936 Saccharomyces cerevisiae heterozygote barcoded mutants were grown competitively in the presence of sub-lethal doses of three nitrogen-containing bisphosphonates (risedronate, alendronate and ibandronate). Strains carrying deletions in genes encoding potential drug targets show a variation of the intensity of their corresponding barcodes on the hybridization array over the time. Results With this approach, we identified novel targets of nitrogen-containing bisphosphonates, such as tubulin cofactor B and ASK/DBF4 (Activator of S-phase kinase). The up-regulation of tubulin cofactor B may explain some previously unknown effects of nitrogen-containing bisphosphonates on microtubule dynamics and organization. As nitrogen-containing bisphosphonates induce extensive DNA damage, we also document the role of DBF4 as a key player in nitrogen-containing bisphosphonate-induced cytotoxicity, thus explaining the effects on the cell-cycle. Conclusions The dataset obtained from the yeast screen was validated in a mammalian system, allowing the discovery of new biological processes involved in the cellular response to nitrogen-containing bisphosphonates and opening up opportunities for development of new anticancer drugs.
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Affiliation(s)
- Nicoletta Bivi
- Department of Biomedical Sciences and Technologies, University of Udine, Piazzale Kolbe, 33100, Udine, Italy.
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