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Hara K, Tatsukawa K, Nagata K, Iida N, Hishiki A, Ohashi E, Hashimoto H. Structural basis for intra- and intermolecular interactions on RAD9 subunit of 9-1-1 checkpoint clamp implies functional 9-1-1 regulation by RHINO. J Biol Chem 2024; 300:105751. [PMID: 38354779 PMCID: PMC10937111 DOI: 10.1016/j.jbc.2024.105751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/03/2024] [Accepted: 02/06/2024] [Indexed: 02/16/2024] Open
Abstract
Eukaryotic DNA clamp is a trimeric protein featuring a toroidal ring structure that binds DNA on the inside of the ring and multiple proteins involved in DNA transactions on the outside. Eukaryotes have two types of DNA clamps: the replication clamp PCNA and the checkpoint clamp RAD9-RAD1-HUS1 (9-1-1). 9-1-1 activates the ATR-CHK1 pathway in DNA damage checkpoint, regulating cell cycle progression. Structure of 9-1-1 consists of two moieties: a hetero-trimeric ring formed by PCNA-like domains of three subunits and an intrinsically disordered C-terminal region of the RAD9 subunit, called RAD9 C-tail. The RAD9 C-tail interacts with the 9-1-1 ring and disrupts the interaction between 9-1-1 and DNA, suggesting a negative regulatory role for this intramolecular interaction. In contrast, RHINO, a 9-1-1 binding protein, interacts with both RAD1 and RAD9 subunits, positively regulating checkpoint activation by 9-1-1. This study presents a biochemical and structural analysis of intra- and inter-molecular interactions on the 9-1-1 ring. Biochemical analysis indicates that RAD9 C-tail binds to the hydrophobic pocket on the PCNA-like domain of RAD9, implying that the pocket is involved in multiple protein-protein interactions. The crystal structure of the 9-1-1 ring in complex with a RHINO peptide reveals that RHINO binds to the hydrophobic pocket of RAD9, shedding light on the RAD9-binding motif. Additionally, the study proposes a structural model of the 9-1-1-RHINO quaternary complex. Together, these findings provide functional insights into the intra- and inter-molecular interactions on the front side of RAD9, elucidating the roles of RAD9 C-tail and RHINO in checkpoint activation.
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Affiliation(s)
- Kodai Hara
- School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Kensuke Tatsukawa
- Graduate School of Systems Life Sciences, Kyushu University, Fukuoka, Japan
| | - Kiho Nagata
- School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Nao Iida
- School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Asami Hishiki
- School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Eiji Ohashi
- Faculty of Science, Department of Biology, Kyushu University, Fukuoka, Japan; Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga, Japan
| | - Hiroshi Hashimoto
- School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan.
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2
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DNA binding by the Rad9A subunit of the Rad9-Rad1-Hus1 complex. PLoS One 2022; 17:e0272645. [PMID: 35939452 PMCID: PMC9359528 DOI: 10.1371/journal.pone.0272645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 07/22/2022] [Indexed: 11/19/2022] Open
Abstract
The Rad9-Rad1-Hus1 checkpoint clamp activates the DNA damage response and promotes DNA repair. DNA loading on the central channel of the Rad9-Rad1-Hus1 complex is required to execute its biological functions. Because Rad9A has the highest DNA affinity among the three subunits, we determined the domains and functional residues of human Rad9A that are critical for DNA interaction. The N-terminal globular domain (residues 1–133) had 3.7-fold better DNA binding affinity than the C-terminal globular domain (residues 134–266) of Rad9A1-266. Rad9A1-266 binds DNA 16-, 60-, and 30-fold better than Rad9A1-133, Rad9A134-266, and Rad9A94-266, respectively, indicating that different regions cooperatively contribute to DNA binding. We show that basic residues including K11, K15, R22, K78, K220, and R223 are important for DNA binding. The reductions on DNA binding of Ala substituted mutants of these basic residues show synergistic effect and are dependent on their residential Rad9A deletion constructs. Interestingly, deletion of a loop (residues 160–163) of Rad9A94-266 weakens DNA binding activity by 4.1-fold as compared to wild-type (WT) Rad9A94-266. Cellular sensitivity to genotoxin of rad9A knockout cells is restored by expressing WT-Rad9Afull. However, rad9A knockout cells expressing Rad9A mutants defective in DNA binding are more sensitive to H2O2 as compared to cells expressing WT-Rad9Afull. Only the rad9A knockout cells expressing loop-deleted Rad9A mutant are more sensitive to hydroxyurea than cells expressing WT-Rad9A. In addition, Rad9A-DNA interaction is required for DNA damage signaling activation. Our results indicate that DNA association by Rad9A is critical for maintaining cell viability and checkpoint activation under stress.
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Sims JR, Faça VM, Pereira C, Ascenção C, Comstock W, Badar J, Arroyo-Martinez GA, Freire R, Cohen PE, Weiss RS, Smolka MB. Phosphoproteomics of ATR signaling in mouse testes. eLife 2022; 11:e68648. [PMID: 35133275 PMCID: PMC8824463 DOI: 10.7554/elife.68648] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 12/22/2021] [Indexed: 11/13/2022] Open
Abstract
The phosphatidylinositol 3' kinase (PI3K)-related kinase ATR is crucial for mammalian meiosis. ATR promotes meiotic progression by coordinating key events in DNA repair, meiotic sex chromosome inactivation (MSCI), and checkpoint-dependent quality control during meiotic prophase I. Despite its central roles in meiosis, the ATR-dependent meiotic signaling network remains largely unknown. Here, we used phosphoproteomics to define ATR signaling events in testes from mice following chemical and genetic ablation of ATR signaling. Quantitative analysis of phosphoproteomes obtained after germ cell-specific genetic ablation of the ATR activating 9-1-1 complex or treatment with ATR inhibitor identified over 14,000 phosphorylation sites from testes samples, of which 401 phosphorylation sites were found to be dependent on both the 9-1-1 complex and ATR. Our analyses identified ATR-dependent phosphorylation events in crucial DNA damage signaling and DNA repair proteins including TOPBP1, SMC3, MDC1, RAD50, and SLX4. Importantly, we identified ATR and RAD1-dependent phosphorylation events in proteins involved in mRNA regulatory processes, including SETX and RANBP3, whose localization to the sex body was lost upon ATR inhibition. In addition to identifying the expected ATR-targeted S/T-Q motif, we identified enrichment of an S/T-P-X-K motif in the set of ATR-dependent events, suggesting that ATR promotes signaling via proline-directed kinase(s) during meiosis. Indeed, we found that ATR signaling is important for the proper localization of CDK2 in spermatocytes. Overall, our analysis establishes a map of ATR signaling in mouse testes and highlights potential meiotic-specific actions of ATR during prophase I progression.
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Affiliation(s)
- Jennie R Sims
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | - Vitor M Faça
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São PauloRibeirão PretoBrazil
| | - Catalina Pereira
- Department of Biomedical Sciences, Cornell UniversityIthacaUnited States
| | - Carolline Ascenção
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | - William Comstock
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | - Jumana Badar
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | | | - Raimundo Freire
- Unidad de Investigación, Hospital Universitario de CanariasTenerifeSpain
- Instituto de Tecnologías Biomédicas, Universidad de La LagunaLa LagunaSpain
- Universidad Fernando Pessoa CanariasLas Palmas de Gran CanariaSpain
| | - Paula E Cohen
- Department of Biomedical Sciences, Cornell UniversityIthacaUnited States
| | - Robert S Weiss
- Department of Biomedical Sciences, Cornell UniversityIthacaUnited States
| | - Marcus B Smolka
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
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4
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Biochemical analysis of TOPBP1 oligomerization. DNA Repair (Amst) 2020; 96:102973. [PMID: 32987353 DOI: 10.1016/j.dnarep.2020.102973] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 08/20/2020] [Accepted: 09/09/2020] [Indexed: 11/24/2022]
Abstract
TOPBP1 is an important scaffold protein that helps orchestrate the cellular response to DNA damage. Although it has been previously appreciated that TOPBP1 can form oligomers, how this occurs and the functional consequences for oligomerization were not yet known. Here, we use protein binding assays and other biochemical techniques to study how TOPBP1 self associates. TOPBP1 contains 9 copies of the BRCT domain, and we report that a subset of these BRCT domains interact with one another to drive oligomerization. An intact BRCT 2 domain is required for TOPBP1 oligomerization and we find that the BRCT1&2 region of TOPBP1 interacts with itself and with the BRCT4&5 pair. RAD9 and RHINO are two heterologous binding partners for TOPBP1's BRCT 1&2 domains, and we show that binding of these partners does not come at the expense of TOPBP1 oligomerization. Furthermore, we show that a TOPBP1 oligomer can simultaneously interact with both RAD9 and RHINO. Lastly, we find that the oligomeric state necessary for TOPBP1 to activate the ATR protein kinase is likely to be a tetramer.
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Pereira C, Smolka MB, Weiss RS, Brieño-Enríquez MA. ATR signaling in mammalian meiosis: From upstream scaffolds to downstream signaling. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:752-766. [PMID: 32725817 PMCID: PMC7747128 DOI: 10.1002/em.22401] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 07/16/2020] [Accepted: 07/24/2020] [Indexed: 05/03/2023]
Abstract
In germ cells undergoing meiosis, the induction of double strand breaks (DSBs) is required for the generation of haploid gametes. Defects in the formation, detection, or recombinational repair of DSBs often result in defective chromosome segregation and aneuploidies. Central to the ability of meiotic cells to properly respond to DSBs are DNA damage response (DDR) pathways mediated by DNA damage sensor kinases. DDR signaling coordinates an extensive network of DDR effectors to induce cell cycle arrest and DNA repair, or trigger apoptosis if the damage is extensive. Despite their importance, the functions of DDR kinases and effector proteins during meiosis remain poorly understood and can often be distinct from their known mitotic roles. A key DDR kinase during meiosis is ataxia telangiectasia and Rad3-related (ATR). ATR mediates key signaling events that control DSB repair, cell cycle progression, and meiotic silencing. These meiotic functions of ATR depend on upstream scaffolds and regulators, including the 9-1-1 complex and TOPBP1, and converge on many downstream effectors such as the checkpoint kinase CHK1. Here, we review the meiotic functions of the 9-1-1/TOPBP1/ATR/CHK1 signaling pathway during mammalian meiosis.
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Affiliation(s)
- Catalina Pereira
- Department of Biomedical Sciences, Cornell University, Ithaca, NY
| | - Marcus B. Smolka
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Robert S. Weiss
- Department of Biomedical Sciences, Cornell University, Ithaca, NY
| | - Miguel A. Brieño-Enríquez
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA
- Corresponding author: ; Phone: 412-641-7531
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6
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Xu J, Wang G, Gong W, Guo S, Li D, Zhan Q. The noncoding function of NELFA mRNA promotes the development of oesophageal squamous cell carcinoma by regulating the Rad17-RFC2-5 complex. Mol Oncol 2020; 14:611-624. [PMID: 31845510 PMCID: PMC7053240 DOI: 10.1002/1878-0261.12619] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 11/27/2019] [Accepted: 12/13/2019] [Indexed: 12/11/2022] Open
Abstract
Recently, RNAs interacting with proteins have been implicated in playing an important role in the occurrence and progression of oesophageal squamous cell carcinoma (ESCC). In this study, we found that NELFA mRNA interacts with Rad17 through a novel noncoding mode in the nucleus and that the aberrant expression of USF2 contributed to the upregulation of Rad17 and NELFA. Subsequent experiments demonstrated that the deletion of NELFA mRNA significantly decreased ESCC proliferation and colony formation in vitro. Moreover, NELFA mRNA knockdown inhibited DNA damage repair and promoted apoptosis. Mechanistic studies indicated that NELFA mRNA regulated the interaction between Rad17 and RFC2‐5, which had a major impact on the phosphorylation of CHK1, CHK2 and BRCA1. NELFA mRNA expression was consistently elevated in ESCC patients and closely related to decreased overall survival. Taken together, our results confirmed the critical role of the noncoding function of NELFA mRNA in ESCC tumorigenesis and indicated that NELFA mRNA can be regarded as a therapeutic target and an independent prognostic indicator in ESCC patients.
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Affiliation(s)
- Jiancheng Xu
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Guangchao Wang
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wei Gong
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shichao Guo
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Dan Li
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qimin Zhan
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Laboratory of Molecular Oncology, Peking University Cancer Hospital and Institute, Beijing, China
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7
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Zhou ZQ, Zhao JJ, Chen CL, Liu Y, Zeng JX, Wu ZR, Tang Y, Zhu Q, Weng DS, Xia JC. HUS1 checkpoint clamp component (HUS1) is a potential tumor suppressor in primary hepatocellular carcinoma. Mol Carcinog 2018; 58:76-87. [PMID: 30182378 DOI: 10.1002/mc.22908] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 08/18/2018] [Accepted: 08/31/2018] [Indexed: 12/14/2022]
Abstract
The HUS1 checkpoint clamp component (HUS1), which is a member of an evolutionarily conserved, genotoxin-activated checkpoint complex (Rad9-Rad1-Hus1 [9-1-1] complex), is involved in cell cycle arrest and DNA repair in response to DNA damage. We conducted this study to investigate the biological significances of HUS1 expression in hepatocellular carcinoma (HCC) development. The mRNA and protein expression levels of HUS1 were determined using Real-time PCR and Western blot, respectively. One hundered and twenty four paraffin sections from HCC tissues were analyzed by immunohistochemistry to assess the association between HUS1 expression and clinicopathological characteristics of patients. The Kaplan-Meier method was performed to calculate the OS and RFS curves. Cell proliferation and colony formation assays, cell migration and invasion assays and cell cycle assays were used to determine the suppressor role of HUS1 in vitro. A mouse model was used to determine the effect of HUS1 on tumorigenesis. The expression of HUS1 was significantly decreased in HCC cell lines and tissues, and low HUS1 expression was associated with poor prognosis of HCC patients. Upregulation of HUS1 expression inhibited the cell proliferation, colony formation, migration, and invasion, as well as arrested cell cycle at G0/G1 in HCC cells in vitro. Moreover, sufficient HUS1 expression inhibited the tumor growth in nude mice. Our study revealed for the first time that HUS1 is a potential tumor suppressor that might produce an antitumor effect in human HCC. Furthermore, HUS1 may serve as a prognostic indicator and could be used for therapeutic application in HCC patients.
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Affiliation(s)
- Zi-Qi Zhou
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Department of Biotherapy, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Jing-Jing Zhao
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Department of Biotherapy, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Chang-Long Chen
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Department of Biotherapy, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Yuan Liu
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Department of Biotherapy, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Jian-Xiong Zeng
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Department of Biotherapy, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Zheng-Rong Wu
- Department of Pathology, School of Basic Medicine, Southern Medical University, Guangzhou, China
| | - Yan Tang
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Department of Biotherapy, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Qian Zhu
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Department of Biotherapy, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - De-Sheng Weng
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Department of Biotherapy, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Jian-Chuan Xia
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Department of Biotherapy, Sun Yat-sen University Cancer Center, Guangzhou, China
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8
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Ohashi E, Tsurimoto T. Functions of Multiple Clamp and Clamp-Loader Complexes in Eukaryotic DNA Replication. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1042:135-162. [PMID: 29357057 DOI: 10.1007/978-981-10-6955-0_7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Proliferating cell nuclear antigen (PCNA) and replication factor C (RFC) were identified in the late 1980s as essential factors for replication of simian virus 40 DNA in human cells, by reconstitution of the reaction in vitro. Initially, they were only thought to be involved in the elongation stage of DNA replication. Subsequent studies have demonstrated that PCNA functions as more than a replication factor, through its involvement in multiple protein-protein interactions. PCNA appears as a functional hub on replicating and replicated chromosomal DNA and has an essential role in the maintenance genome integrity in proliferating cells.Eukaryotes have multiple paralogues of sliding clamp, PCNA and its loader, RFC. The PCNA paralogues, RAD9, HUS1, and RAD1 form the heterotrimeric 9-1-1 ring that is similar to the PCNA homotrimeric ring, and the 9-1-1 clamp complex is loaded onto sites of DNA damage by its specific loader RAD17-RFC. This alternative clamp-loader system transmits DNA-damage signals in genomic DNA to the checkpoint-activation network and the DNA-repair apparatus.Another two alternative loader complexes, CTF18-RFC and ELG1-RFC, have roles that are distinguishable from the role of the canonical loader, RFC. CTF18-RFC interacts with one of the replicative DNA polymerases, Polε, and loads PCNA onto leading-strand DNA, and ELG1-RFC unloads PCNA after ligation of lagging-strand DNA. In the progression of S phase, these alternative PCNA loaders maintain appropriate amounts of PCNA on the replicating sister DNAs to ensure that specific enzymes are tethered at specific chromosomal locations.
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Affiliation(s)
- Eiji Ohashi
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
| | - Toshiki Tsurimoto
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan.
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9
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Mrc1/Claspin: a new role for regulation of origin firing. Curr Genet 2017; 63:813-818. [DOI: 10.1007/s00294-017-0690-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 03/20/2017] [Accepted: 03/22/2017] [Indexed: 12/12/2022]
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10
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Yang CC, Suzuki M, Yamakawa S, Uno S, Ishii A, Yamazaki S, Fukatsu R, Fujisawa R, Sakimura K, Tsurimoto T, Masai H. Claspin recruits Cdc7 kinase for initiation of DNA replication in human cells. Nat Commun 2016; 7:12135. [PMID: 27401717 PMCID: PMC4945878 DOI: 10.1038/ncomms12135] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 06/03/2016] [Indexed: 11/09/2022] Open
Abstract
Claspin transmits replication stress signal from ATR to Chk1 effector kinase as a mediator. It also plays a role in efficient replication fork progression during normal growth. Here we have generated conditional knockout of Claspin and show that Claspin knockout mice are dead by E12.5 and Claspin knockout mouse embryonic fibroblast (MEF) cells show defect in S phase. Using the mutant cell lines, we report the crucial roles of the acidic patch (AP) near the C terminus of Claspin in initiation of DNA replication. Cdc7 kinase binds to AP and this binding is required for phosphorylation of Mcm. AP is involved also in intramolecular interaction with a N-terminal segment, masking the DNA-binding domain and a newly identified PIP motif, and Cdc7-mediated phosphorylation reduces the intramolecular interaction. Our results suggest a new role of Claspin in initiation of DNA replication during normal S phase through the recruitment of Cdc7 that facilitates phosphorylation of Mcm proteins. Claspin mediates the transmission of a replication-stress signal from ATR to Chk1 and is necessary for efficient fork progression. Here the authors demonstrate that the C-terminal acidic patch is important for this role due to its interaction with Cdc7.
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Affiliation(s)
- Chi-Chun Yang
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Masahiro Suzuki
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Shiori Yamakawa
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Syuzi Uno
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Ai Ishii
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Satoshi Yamazaki
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Rino Fukatsu
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Ryo Fujisawa
- Department of Biology, Faculty of Science, Kyushu University 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Toshiki Tsurimoto
- Department of Biology, Faculty of Science, Kyushu University 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hisao Masai
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
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