1
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Li WJ, Huang Y, Lin YA, Zhang BD, Li MY, Zou YQ, Hu GS, He YH, Yang JJ, Xie BL, Huang HH, Deng X, Liu W. Targeting PRMT1-mediated SRSF1 methylation to suppress oncogenic exon inclusion events and breast tumorigenesis. Cell Rep 2023; 42:113385. [PMID: 37938975 DOI: 10.1016/j.celrep.2023.113385] [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: 01/14/2023] [Revised: 08/10/2023] [Accepted: 10/23/2023] [Indexed: 11/10/2023] Open
Abstract
PRMT1 plays a vital role in breast tumorigenesis; however, the underlying molecular mechanisms remain incompletely understood. Herein, we show that PRMT1 plays a critical role in RNA alternative splicing, with a preference for exon inclusion. PRMT1 methylome profiling identifies that PRMT1 methylates the splicing factor SRSF1, which is critical for SRSF1 phosphorylation, SRSF1 binding with RNA, and exon inclusion. In breast tumors, PRMT1 overexpression is associated with increased SRSF1 arginine methylation and aberrant exon inclusion, which are critical for breast cancer cell growth. In addition, we identify a selective PRMT1 inhibitor, iPRMT1, which potently inhibits PRMT1-mediated SRSF1 methylation, exon inclusion, and breast cancer cell growth. Combination treatment with iPRMT1 and inhibitors targeting SRSF1 phosphorylation exhibits an additive effect of suppressing breast cancer cell growth. In conclusion, our study dissects a mechanism underlying PRMT1-mediated RNA alternative splicing. Thus, PRMT1 has great potential as a therapeutic target in breast cancer treatment.
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Affiliation(s)
- Wen-Juan Li
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Ying Huang
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Yi-An Lin
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Bao-Ding Zhang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China
| | - Mei-Yan Li
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Yi-Qin Zou
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Guo-Sheng Hu
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Yao-Hui He
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Jing-Jing Yang
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Bing-Lan Xie
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China
| | - Hai-Hua Huang
- Department of Pathology, The Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong, China
| | - Xianming Deng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China.
| | - Wen Liu
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China.
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2
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Fukumoto Y, Hoshino T, Nakayama Y, Ogra Y. The C-terminal tail of Rad17, iVERGE, binds the 9‒1‒1 complex independently of AAA+ ATPase domains to provide another clamp-loader interface. DNA Repair (Amst) 2023; 130:103567. [PMID: 37713925 DOI: 10.1016/j.dnarep.2023.103567] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 08/17/2023] [Accepted: 09/03/2023] [Indexed: 09/17/2023]
Abstract
The ATR pathway plays a crucial role in maintaining genome integrity as the major DNA damage checkpoint. It also attracts attention as a therapeutic target in cancer treatment. The Rad17-RFC2-5 complex loads the Rad9-Hus1-Rad1 (9-1-1) DNA clamp complex onto damaged chromatin to activate the ATR pathway. We previously reported that phosphorylation of a polyanionic C-terminal tail of human Rad17, iVERGE, is essential for the interaction between Rad17 and the 9-1-1 complex. However, the molecular mechanism has remained unclear. Here, we show that iVERGE directly interacts with the Hus1 subunit of the 9-1-1 complex through Rad17-S667 phosphorylation independently of the AAA+ ATPase domains. An exogenous iVERGE peptide interacted with the 9-1-1 complex in vivo. The binding conformation of the iVERGE peptide was analyzed by de novo modeling with docking simulation, simulated annealing-molecular dynamics simulation, and the fragment molecular orbital method. The in silico analyses predicted the association of the iVERGE peptide with the hydrophobic and basic patches on the Hus1 protein, and the corresponding Hus1 mutants were deficient in the interaction with the iVERGE peptide in vivo. The iVERGE peptide occupied the same position as the C-terminus of Saccharomyces cerevisiae RAD24 on MEC3. The interaction energy calculation suggested that the Rad17 KYxxL motif and the iVERGE peptide are the primary and secondary interaction surfaces between the Rad17-RFC2-5 and 9-1-1 complexes. Our data reveal a novel molecular interface, iVERGE, between the Rad17-RFC2-5 and 9-1-1 complexes in vertebrates and implicate that Rad17 utilizes two distinct molecular interfaces to regulate the 9-1-1 complex.
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Affiliation(s)
- Yasunori Fukumoto
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan.
| | - Tyuji Hoshino
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Yuji Nakayama
- Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Yasumitsu Ogra
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
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3
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Uchida C, Niida H, Sakai S, Iijima K, Kitagawa K, Ohhata T, Shiotani B, Kitagawa M. p130RB2 positively contributes to ATR activation in response to replication stress via the RPA32-ETAA1 axis. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119484. [PMID: 37201767 DOI: 10.1016/j.bbamcr.2023.119484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 03/17/2023] [Accepted: 04/23/2023] [Indexed: 05/20/2023]
Abstract
Ataxia-telangiectasia mutated and Rad3-related (ATR) kinase is a crucial regulator of the cell cycle checkpoint and activated in response to DNA replication stress by two independent pathways via RPA32-ETAA1 and TopBP1. However, the precise activation mechanism of ATR by the RPA32-ETAA1 pathway remains unclear. Here, we show that p130RB2, a member of the retinoblastoma protein family, participates in the pathway under hydroxyurea-induced DNA replication stress. p130RB2 binds to ETAA1, but not TopBP1, and depletion of p130RB2 inhibits the RPA32-ETAA1 interaction under replication stress. Moreover, p130RB2 depletion reduces ATR activation accompanied by phosphorylation of its targets RPA32, Chk1, and ATR itself. It also causes improper re-progression of S phase with retaining single-stranded DNA after cancelation of the stress, which leads to an increase in the anaphase bridge phenotype and a decrease in cell survival. Importantly, restoration of p130RB2 rescued the disrupted phenotypes of p130RB2 knockdown cells. These results suggest positive involvement of p130RB2 in the RPA32-ETAA1-ATR axis and proper re-progression of the cell cycle to maintain genome integrity.
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Affiliation(s)
- Chiharu Uchida
- Advanced Research Facilities & Services, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan.
| | - Hiroyuki Niida
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Satoshi Sakai
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Kenta Iijima
- Laboratory Animal Facilities & Services, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Kyoko Kitagawa
- Department of Environmental Health, University of Occupational and Environmental Health, Kitakyushu, Fukuoka 807-8555, Japan
| | - Tatsuya Ohhata
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Bunsyo Shiotani
- Laboratory of Genome Stress Signaling, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan
| | - Masatoshi Kitagawa
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
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4
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Fukumoto Y, Ikeuchi M, Qu L, Hoshino T, Yamaguchi N, Nakayama Y, Ogra Y. Nuclear translocation promotes proteasomal degradation of human Rad17 protein through the N-terminal destruction boxes. J Biol Chem 2021; 297:100831. [PMID: 34174284 PMCID: PMC8318897 DOI: 10.1016/j.jbc.2021.100831] [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: 04/19/2021] [Revised: 05/17/2021] [Accepted: 05/24/2021] [Indexed: 12/15/2022] Open
Abstract
The ATR pathway is one of the major DNA damage checkpoints, and Rad17 is a DNA-binding protein that is phosphorylated upon DNA damage by ATR kinase. Rad17 recruits the 9-1-1 complex that mediates the checkpoint activation, and proteasomal degradation of Rad17 is important for recovery from the ATR pathway. Here, we identified several Rad17 mutants deficient in nuclear localization and resistant to proteasomal degradation. The nuclear localization signal was identified in the central basic domain of Rad17. Rad17 Δ230–270 and R240A/L243A mutants that were previously postulated to lack the destruction box, a sequence that is recognized by the ubiquitin ligase/anaphase-promoting complex that mediates degradation of Rad17, also showed cytoplasmic localization. Our data indicate that the nuclear translocation of Rad17 is functionally linked to the proteasomal degradation. The ATP-binding activity of Rad17, but not hydrolysis, is essential for the nuclear translocation, and the ATPase domain orchestrates the nuclear translocation, the proteasomal degradation, as well as the interaction with the 9-1-1 complex. The Rad17 mutant that lacked a nuclear localization signal was proficient in the interaction with the 9-1-1 complex, suggesting cytosolic association of Rad17 and the 9-1-1 complex. Finally, we identified two tandem canonical and noncanonical destruction boxes in the N-terminus of Rad17 as the bona fide destruction box, supporting the role of anaphase-promoting complex in the degradation of Rad17. We propose a model in which Rad17 is activated in the cytoplasm for translocation into the nucleus and continuously degraded in the nucleus even in the absence of exogenous DNA damage.
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Affiliation(s)
- Yasunori Fukumoto
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan.
| | - Masayoshi Ikeuchi
- Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Liang Qu
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
| | - Tyuji Hoshino
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
| | - Naoto Yamaguchi
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
| | - Yuji Nakayama
- Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Yasumitsu Ogra
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
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5
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Kim W, Zhao F, Wu R, Qin S, Nowsheen S, Huang J, Zhou Q, Chen Y, Deng M, Guo G, Luo K, Lou Z, Yuan J. ZFP161 regulates replication fork stability and maintenance of genomic stability by recruiting the ATR/ATRIP complex. Nat Commun 2019; 10:5304. [PMID: 31757956 PMCID: PMC6876566 DOI: 10.1038/s41467-019-13321-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 10/23/2019] [Indexed: 12/03/2022] Open
Abstract
DNA replication stress-mediated activation of the ATR kinase pathway is important for maintaining genomic stability. In this study, we identified a zinc finger protein, ZFP161 that functions as a replication stress response factor in ATR activation. Mechanistically, ZFP161 acts as a scaffolding protein to facilitate the interaction between RPA and ATR/ATRIP. ZFP161 binds to RPA and ATR/ATRIP through distinct regions and stabilizes the RPA–ATR–ATRIP complex at stalled replication forks. This function of ZFP161 is important to the ATR signaling cascade and genome stability maintenance. In addition, ZFP161 knockout mice showed a defect in ATR activation and genomic instability. Furthermore, low expression of ZFP161 is associated with higher cancer risk and chromosomal instability. Overall, these findings suggest that ZFP161 coordinates ATR/Chk1 pathway activation and helps maintain genomic stability. The ATR pathway is active during DNA replication stress to maintain genome stability. Here the authors reveal the role of the zinc finger containing protein 161 (ZFP161) to facilitate replication fork stability by acting as a scaffold to facilitate the interaction between RPA and ATR/ATRIP.
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Affiliation(s)
- Wootae Kim
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Fei Zhao
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Rentian Wu
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Sisi Qin
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA
| | - Somaira Nowsheen
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA.,Mayo Clinic Medical Scientist Training Program, Mayo Clinic Alix School Of Medicine and Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN, 55905, USA
| | - Jinzhou Huang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Qin Zhou
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Yuping Chen
- Research Center for Translational Medicine, East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai, 200120, China.,Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai, 200120, China
| | - Min Deng
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Guijie Guo
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Kuntian Luo
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Zhenkun Lou
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA. .,Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA.
| | - Jian Yuan
- Research Center for Translational Medicine, East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai, 200120, China. .,Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai, 200120, China.
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6
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Fukumoto Y, Nakayama Y, Yamaguchi N. The polyanionic C-terminal tail of human Rad17 regulates interaction with the 9–1–1 complex. Biochem Biophys Res Commun 2017; 490:1147-1153. [DOI: 10.1016/j.bbrc.2017.06.159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 06/27/2017] [Indexed: 02/06/2023]
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7
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Li R, Wang W, Li F, Wang Q, Wang S, Xu Y, Chen F. Response of alternative splice isoforms of OsRad9 gene from Oryza sativa to environmental stress. ACTA ACUST UNITED AC 2017; 72:325-334. [DOI: 10.1515/znc-2016-0257] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 02/11/2017] [Indexed: 12/16/2022]
Abstract
Abstract
Rad9 protein plays an important role in cell-cycle checkpoint signal transduction in human and yeast cells, but knowledge about Rad9 in plants is limited. This study reports that the Rad9 gene of rice can generate the transcript products OsRad9.1 and OsRad9.2 through alternative splicing. OsRad9.1, with all nine exons, is the main cell-cycle checkpoint protein involved in the response of rice to genotoxic stresses (ultraviolet radiation and antibiotic stress), environmental stresses (drought, salt, and heavy metal stress), and auxin stimuli (2,4-D, IAA, and IBA). Meanwhile, transcript isoform OsRad9.2, which lost exon7 and exon8, showed different preferential stimulation effects on these stresses and pollen development duration. These results might indicat that besides the monitoring and repair of DNA damage, Rad9 might involve in the development of pollen.
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Affiliation(s)
- Rui Li
- College of Pharmacy and Biological Engineering , Chengdu University , 1 Shiling , Chengdu 610106 , China
| | - Wenguo Wang
- Biogas Institute of Ministry of Agriculture , Chengdu 610041 , China
| | - Fosheng Li
- Key Lab of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science , Sichuan University , Chengdu 610064 , China
| | - Qingwei Wang
- Key Lab of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science , Sichuan University , Chengdu 610064 , China
| | - Shenghua Wang
- Key Lab of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science , Sichuan University , Chengdu 610064 , China
| | - Ying Xu
- Key Lab of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science , Sichuan University , Chengdu 610064 , China , Tel.: +86 28 85417281, Fax: 86 028 85417281
| | - Fang Chen
- Key Lab of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science , Sichuan University , Chengdu 610064 , China
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8
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Fukumoto Y, Ikeuchi M, Nakayama Y, Yamaguchi N. The KYxxL motif in Rad17 protein is essential for the interaction with the 9-1-1 complex. Biochem Biophys Res Commun 2016; 477:982-987. [PMID: 27387238 DOI: 10.1016/j.bbrc.2016.07.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 07/02/2016] [Indexed: 11/28/2022]
Abstract
ATR-dependent DNA damage checkpoint is the major DNA damage checkpoint against UV irradiation and DNA replication stress. The Rad17-RFC and Rad9-Rad1-Hus1 (9-1-1) complexes interact with each other to contribute to ATR signaling, however, the precise regulatory mechanism of the interaction has not been established. Here, we identified a conserved sequence motif, KYxxL, in the AAA+ domain of Rad17 protein, and demonstrated that this motif is essential for the interaction with the 9-1-1 complex. We also show that UV-induced Rad17 phosphorylation is increased in the Rad17 KYxxL mutants. These data indicate that the interaction with the 9-1-1 complex is not required for Rad17 protein to be an efficient substrate for the UV-induced phosphorylation. Our data also raise the possibility that the 9-1-1 complex plays a negative regulatory role in the Rad17 phosphorylation. We also show that the nucleotide-binding activity of Rad17 is required for its nuclear localization.
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Affiliation(s)
- Yasunori Fukumoto
- Laboratory of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan.
| | - Masayoshi Ikeuchi
- Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Yuji Nakayama
- Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Naoto Yamaguchi
- Laboratory of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan.
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9
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Chk1 Activation Protects Rad9A from Degradation as Part of a Positive Feedback Loop during Checkpoint Signalling. PLoS One 2015; 10:e0144434. [PMID: 26658951 PMCID: PMC4676731 DOI: 10.1371/journal.pone.0144434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 11/18/2015] [Indexed: 11/19/2022] Open
Abstract
Phosphorylation of Rad9A at S387 is critical for establishing a physical interaction with TopBP1, and to downstream activation of Chk1 for checkpoint activation. We have previously demonstrated a phosphorylation of Rad9A that occurs at late time points in cells exposed to genotoxic agents, which is eliminated by either Rad9A overexpression, or conversion of S387 to a non-phosphorylatable analogue. Based on this, we hypothesized that this late Rad9A phosphorylation is part of a feedback loop regulating the checkpoint. Here, we show that Rad9A is hyperphosphorylated and accumulates in cells exposed to bleomycin. Following the removal of bleomycin, Rad9A is polyubiquitinated, and Rad9A protein levels drop, indicating an active degradation process for Rad9A. Chk1 inhibition by UCN-01 or siRNA reduces Rad9A levels in cells synchronized in S-phase or exposed to DNA damage, indicating that Chk1 activation is required for Rad9A stabilization in S-phase and during checkpoint activation. Together, these results demonstrate a positive feedback loop involving Rad9A-dependend activation of Chk1, coupled with Chk1-dependent stabilization of Rad9A that is critical for checkpoint regulation.
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10
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Fukumoto Y, Miura T, Morii M, Kubota S, Honda T, Kubota S, Morinaga T, Yamaguchi N, Nakayama Y, Yamaguchi N. v-Src inhibits the interaction between Rad17 and Rad9 and induces replication fork collapse. Biochem Biophys Res Commun 2014; 450:885-90. [DOI: 10.1016/j.bbrc.2014.06.078] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 06/17/2014] [Indexed: 12/27/2022]
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11
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Mailand N, Gibbs-Seymour I, Bekker-Jensen S. Regulation of PCNA-protein interactions for genome stability. Nat Rev Mol Cell Biol 2013; 14:269-82. [PMID: 23594953 DOI: 10.1038/nrm3562] [Citation(s) in RCA: 265] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Proliferating cell nuclear antigen (PCNA) has a central role in promoting faithful DNA replication, providing a molecular platform that facilitates the myriad protein-protein and protein-DNA interactions that occur at the replication fork. Numerous PCNA-associated proteins compete for binding to a common surface on PCNA; hence these interactions need to be tightly regulated and coordinated to ensure proper chromosome replication and integrity. Control of PCNA-protein interactions is multilayered and involves post-translational modifications, in particular ubiquitylation, accessory factors and regulated degradation of PCNA-associated proteins. This regulatory framework allows cells to maintain a fine-tuned balance between replication fidelity and processivity in response to DNA damage.
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Affiliation(s)
- Niels Mailand
- Ubiquitin Signaling Group, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
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12
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Pérez-Castro AJ, Freire R. Rad9B responds to nucleolar stress through ATR and JNK signalling, and delays the G1-S transition. J Cell Sci 2012; 125:1152-64. [PMID: 22399810 DOI: 10.1242/jcs.091124] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The complex formed by Rad9, Rad1 and Hus1 (9-1-1) protects against genomic instability by activating DNA damage checkpoint and DNA damage repair pathways, mainly in response to replication fork collapse and UV lesions. Here we compare the role of Rad9A (also known as Rad9) with the human paralogue Rad9B. Unlike Rad9A, overexpression of Rad9B delays cells in G1 phase. Moreover, Rad9B migrates to nucleoli after nucleolar stress in an ATR- and JNK-dependent manner, in a newly described nucleolar domain structure containing p21. Analysis of chimeras of Rad9A and Rad9B demonstrate that localisation to nucleoli and the block in G1 phase upon overexpression crucially depend on the Rad9B C-terminal tail. Taken together, data presented here show a relationship between Rad9B and pathways for checkpoints, stress response and nucleolar function.
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Affiliation(s)
- Antonio Jesús Pérez-Castro
- Unidad de Investigación, Hospital Universitario de Canarias, Instituto de Tecnologías Biomédicas, Ofra s/n, La Laguna, Tenerife, Spain
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13
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Gray K, Bennett M. Role of DNA damage in atherosclerosis—Bystander or participant? Biochem Pharmacol 2011; 82:693-700. [DOI: 10.1016/j.bcp.2011.06.025] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 06/16/2011] [Accepted: 06/17/2011] [Indexed: 10/18/2022]
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14
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Targeted deletion of mouse Rad1 leads to deficient cellular DNA damage responses. Protein Cell 2011; 2:410-22. [PMID: 21637962 DOI: 10.1007/s13238-011-1049-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2011] [Accepted: 05/05/2011] [Indexed: 10/18/2022] Open
Abstract
The Rad1 gene is evolutionarily conserved from yeast to human. The fission yeast Schizosaccharomyces pombe Rad1 ortholog promotes cell survival against DNA damage and is required for G(2)/M checkpoint activation. In this study, mouse embryonic stem (ES) cells with a targeted deletion of Mrad1, the mouse ortholog of this gene, were created to evaluate its function in mammalian cells. Mrad1 (-/-) ES cells were highly sensitive to ultraviolet-light (UV light), hydroxyurea (HU) and gamma rays, and were defective in G(2)/M as well as S/M checkpoints. These data indicate that Mrad1 is required for repairing DNA lesions induced by UV-light, HU and gamma rays, and for mediating G(2)/M and S/M checkpoint controls. We further demonstrated that Mrad1 plays an important role in homologous recombination repair (HRR) in ES cells, but a minor HRR role in differentiated mouse cells.
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15
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Young JL, Koon EC, Kwong J, Welch WR, Muto MG, Berkowitz RS, Mok SC. Differential hRad17 expression by histologic subtype of ovarian cancer. J Ovarian Res 2011; 4:6. [PMID: 21450056 PMCID: PMC3077316 DOI: 10.1186/1757-2215-4-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 03/30/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In the search for unique ovarian cancer biomarkers, ovarian specific cDNA microarray analysis identified hRad17, a cell cycle checkpoint protein, as over-expressed in ovarian cancer. The aim of this study was to validate this expression. METHODS Immunohistochemistry was performed on 72 serous, 19 endometrioid, 10 clear cell, and 6 mucinous ovarian cancers, 9 benign ovarian tumors, and 6 normal ovarian tissue sections using an anti-hRad17 antibody. Western blot analysis and quantitative PCR were performed using cell lysates and total RNA prepared from 17 ovarian cancer cell lines and 6 normal ovarian epithelial cell cultures (HOSE). RESULTS Antibody staining confirmed upregulation of hRad17 in 49.5% of ovarian cancer cases. Immunohistochemistry demonstrated that only 42% of serous and 47% of endometrioid subtypes showed overexpression compared to 80% of clear cell and 100% of mucinous cancers. Western blot confirmed overexpression of hRad17 in cancer cell lines compared to HOSE. Quantitative PCR demonstrated an upregulation of hRad17 RNA by 1.5-7 fold. hRad17 RNA expression differed by subtype. CONCLUSIONS hRad17 is over-expressed in ovarian cancer. This over-expression varies by subtype suggesting a role in the pathogenesis of these types. Functional studies are needed to determine the potential role of this protein in ovarian cancer.
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Affiliation(s)
- Jennifer L Young
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC, USA.
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16
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Khair L, Chang YT, Subramanian L, Russell P, Nakamura TM. Roles of the checkpoint sensor clamp Rad9-Rad1-Hus1 (911)-complex and the clamp loaders Rad17-RFC and Ctf18-RFC in Schizosaccharomyces pombe telomere maintenance. Cell Cycle 2010; 9:2237-48. [PMID: 20505337 DOI: 10.4161/cc.9.11.11920] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
While telomeres must provide mechanisms to prevent DNA repair and DNA damage checkpoint factors from fusing chromosome ends and causing permanent cell cycle arrest, these factors associate with functional telomeres and play critical roles in the maintenance of telomeres. Previous studies have established that Tel1 (ATM) and Rad3 (ATR) kinases play redundant but essential roles for telomere maintenance in fission yeast. In addition, the Rad9-Rad1-Hus1 (911) and Rad17-RFC complexes work downstream of Rad3 (ATR) in fission yeast telomere maintenance. Here, we investigated how 911, Rad17-RFC and another RFC-like complex Ctf18-RFC contribute to telomere maintenance in fission yeast cells lacking Tel1 and carrying a novel hypomorphic allele of rad3 (DBD-rad3), generated by the fusion between the DNA binding domain (DBD) of the fission yeast telomere capping protein Pot1 and Rad3. Our investigations have uncovered a surprising redundancy for Rad9 and Hus1 in allowing Rad1 to contribute to telomere maintenance in DBD-rad3 tel1 cells. In addition, we found that Rad17-RFC and Ctf18-RFC carry out redundant telomere maintenance functions in DBD-rad3 tel1 cells. Since checkpoint sensor proteins are highly conserved, genetic redundancies uncovered here may be relevant to telomere maintenance and detection of DNA damage in other eukaryotes.
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Affiliation(s)
- Lyne Khair
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL, USA
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17
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Morris LGT, Veeriah S, Chan TA. Genetic determinants at the interface of cancer and neurodegenerative disease. Oncogene 2010; 29:3453-64. [PMID: 20418918 DOI: 10.1038/onc.2010.127] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
It has been hypothesized that oncogenesis and neurodegeneration may share common mechanistic foundations. Recent evidence now reveals a number of genes in which alteration leads to either carcinogenesis or neurodegeneration, depending on cellular context. Pathways that have emerged as having critical roles in both cancer and neurodegenerative disease include those involving genes such as PARK2, ATM, PTEN, PTPRD, and mTOR. A number of mechanisms have been implicated, and commonly affected cellular processes include cell cycle regulation, DNA repair, and response to oxidative stress. For example, we have recently shown that the E3 ubiquitin ligase PARK2 is mutated or deleted in many different human malignancies and helps drive loss on chromosome 6q25.2-27, a genomic region frequently deleted in cancers. Mutation in PARK2 is also the most common cause of juvenile Parkinson's disease. Mutations in PARK2 result in an upregulation of its substrate cyclin E, resulting in dysregulated entry into the cell cycle. In neurons, this process results in cell death, but in cycling cells, the result is a growth advantage. Thus, depending on whether the cell affected is a dividing cell or a post-mitotic neuron, responses to these alterations may differ, ultimately leading to varying disease phenotypes. Here, we review the substantial data implicating specific genes in both cancer and neurodegenerative disease.
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Affiliation(s)
- L G T Morris
- Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
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18
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Xu M, Bai L, Gong Y, Xie W, Hang H, Jiang T. Structure and functional implications of the human rad9-hus1-rad1 cell cycle checkpoint complex. J Biol Chem 2009; 284:20457-61. [PMID: 19535328 PMCID: PMC2742809 DOI: 10.1074/jbc.c109.022384] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 06/05/2009] [Indexed: 12/15/2022] Open
Abstract
Cellular DNA lesions are efficiently countered by DNA repair in conjunction with delays in cell cycle progression. Previous studies have demonstrated that Rad9, Hus1, and Rad1 can form a heterotrimeric complex (the 9-1-1 complex) that plays dual roles in cell cycle checkpoint activation and DNA repair in eukaryotic cells. Although the 9-1-1 complex has been proposed to form a toroidal structure similar to proliferating cell nuclear antigen (PCNA), which plays essential roles in DNA replication and repair, the structural basis by which it performs different functions has not been elucidated. Here we report the crystal structure of the human 9-1-1 complex at 3.2 A resolution. The crystal structure, together with biochemical assays, reveals that the interdomain connecting loops (IDC loop) of hRad9, hHus1, and hRad1 are largely divergent, and further cocrystallization study indicates that a PCNA-interacting box (PIP box)-containing peptide derived from hFen1 binds tightly to the interdomain connecting loop of hRad1, providing the molecular basis for the damage repair-specific activity of the 9-1-1 complex in contrast to PCNA. Furthermore, structural comparison with PCNA reveals other unique structural features of the 9-1-1 complex that are proposed to contribute to DNA damage recognition.
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Affiliation(s)
- Min Xu
- From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 and
- the Graduate University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100039, China
| | - Lin Bai
- From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 and
- the Graduate University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100039, China
| | - Yong Gong
- From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 and
| | - Wei Xie
- From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 and
- the Graduate University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100039, China
| | - Haiying Hang
- From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 and
| | - Tao Jiang
- From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 and
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19
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Sohn SY, Cho Y. Crystal structure of the human rad9-hus1-rad1 clamp. J Mol Biol 2009; 390:490-502. [PMID: 19464297 DOI: 10.1016/j.jmb.2009.05.028] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Revised: 05/13/2009] [Accepted: 05/15/2009] [Indexed: 11/17/2022]
Abstract
Three evolutionarily conserved proteins, Rad9, Hus1, and Rad1, form a heterotrimeric 9-1-1 complex that plays critical roles in cellular responses to DNA damage by activating checkpoints and by recruiting DNA repair enzymes to DNA lesions. We have determined the crystal structure of the human Rad9 (residues 1-272)-Hus1-Rad1 complex at 2.5 A resolution. The 9(1-272)-1-1 complex forms a closed ring, with each subunit having a similar structure. Despite its high level of similarity to proliferating cell nucleus antigen in terms of overall structure, the 9(1-272)-1-1 complex exhibits notable differences in local structures, including interdomain connecting loops, H2 and H3 helices, and loops in the vicinity of the helices of each subunit. These local structural variations provide several unique features to the 9-1-1 heterotrimeric complex-including structures of intermolecular interfaces and the inner surface around the central hole, and different electrostatic potentials at and near the interdomain connecting loops of each 9-1-1 subunit-compared to the proliferating cell nucleus antigen trimer. We propose that these structural features allow the 9-1-1 complex to bind to a damaged DNA during checkpoint control and to serve as a platform for base excision repair. We also show that the 9(1-272)-1-1 complex, but not the full-length 9-1-1 complex, forms a stable complex with the 5' recessed DNA, suggesting that the C-terminal tail of Rad9 is involved in the regulation of the 9-1-1 complex in DNA binding.
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Affiliation(s)
- Sun Young Sohn
- National Creative Research Center for Structural Biology and Department of Life Science, Pohang University of Science and Technology, Hyo-ja dong, Pohang, KyungBook, South Korea
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20
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Doré AS, Kilkenny ML, Rzechorzek NJ, Pearl LH. Crystal structure of the rad9-rad1-hus1 DNA damage checkpoint complex--implications for clamp loading and regulation. Mol Cell 2009; 34:735-45. [PMID: 19446481 DOI: 10.1016/j.molcel.2009.04.027] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2009] [Revised: 04/14/2009] [Accepted: 04/23/2009] [Indexed: 10/20/2022]
Abstract
Rad9, Rad1, and Hus1 form a heterotrimeric complex (9-1-1) that is loaded onto DNA at sites of DNA damage. DNA-loaded 9-1-1 activates signaling through the Chk1 arm of the DNA damage checkpoint response via recruitment and stimulation of ATR. Additionally, 9-1-1 may play a direct role in facilitating DNA damage repair via interaction with a number of DNA repair enzymes. We have now determined the crystal structure of the human 9-1-1 complex, revealing a toroidal structure with a similar architecture to the homotrimeric PCNA DNA-binding clamp. The structure explains the formation of a unique heterotrimeric arrangement and reveals significant differences among the three subunits in the sites implicated in binding to the clamp loader and to ligand proteins. Biochemical analysis reveals a single repair enzyme-binding site on 9-1-1 that can be blocked competitively by the PCNA-binding cell-cycle regulator p21(cip1/waf1).
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Affiliation(s)
- Andrew S Doré
- CR-UK DNA Repair Enzymes Group, Section of Structural Biology, The Institute of Cancer Research, 237 Fulham Road, Chelsea, SW36JB London, UK
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21
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Lu S, Li Z, Wang Z, Ma X, Sheng D, Ni J, Shen Y. Spatial subunit distribution and in vitro functions of the novel trimeric PCNA complex from Sulfolobus tokodaii. Biochem Biophys Res Commun 2008; 376:369-74. [DOI: 10.1016/j.bbrc.2008.08.150] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Accepted: 08/29/2008] [Indexed: 10/21/2022]
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22
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Loss of Hus1 sensitizes cells to etoposide-induced apoptosis by regulating BH3-only proteins. Oncogene 2008; 27:7248-59. [PMID: 18794804 DOI: 10.1038/onc.2008.336] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Rad9-Rad1-Hus1 (9-1-1) cell cycle checkpoint complex plays a key role in the DNA damage response. Cells with a defective 9-1-1 complex have been shown to be sensitive to apoptosis induced by certain types of genotoxic stress. However, the mechanism linking the loss of a functional 9-1-1 complex to the cell death machinery has yet to be determined. Here, we report that etoposide treatment dramatically upregulates the BH3-only proteins, Bim and Puma, in Hus1-deficient cells. Inhibition of either Bim or Puma expression in Hus1-knockout cells confers significant resistance to etoposide-induced apoptosis, whereas knockdown of both proteins results in further resistance, suggesting that Bim and Puma cooperate in sensitizing Hus1-deficient cells to etoposide treatment. Moreover, we found that Rad9 collaborates with Bim and Puma to sensitize Hus1-deficient cells to etoposide-induced apoptosis. In response to DNA damage, Rad9 localizes to chromatin in Hus1-wild-type cells, whereas in Hus1-deficient cells, it is predominantly located in the cytoplasm where it binds to Bcl-2. Taken together, these results suggest that loss of Hus1 sensitizes cells to etoposide-induced apoptosis not only by inducing Bim and Puma expressions but also by releasing Rad9 into the cytosol to augment mitochondrial apoptosis.
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23
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Delacroix S, Wagner JM, Kobayashi M, Yamamoto KI, Karnitz LM. The Rad9-Hus1-Rad1 (9-1-1) clamp activates checkpoint signaling via TopBP1. Genes Dev 2007; 21:1472-7. [PMID: 17575048 PMCID: PMC1891424 DOI: 10.1101/gad.1547007] [Citation(s) in RCA: 350] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
DNA replication stress triggers the activation of Checkpoint Kinase 1 (Chk1) in a pathway that requires the independent chromatin loading of the ATRIP-ATR (ATR-interacting protein/ATM [ataxia-telangiectasia mutated]-Rad3-related kinase) complex and the Rad9-Hus1-Rad1 (9-1-1) clamp. We show that Rad9's role in Chk1 activation is to bind TopBP1, which stimulates ATR-mediated Chk1 phosphorylation via TopBP1's activation domain (AD), a domain that binds and activates ATR. Notably, fusion of the AD to proliferating cell nuclear antigen (PCNA) or histone H2B bypasses the requirement for the 9-1-1 clamp, indicating that the 9-1-1 clamp's primary role in activating Chk1 is to localize the AD to a stalled replication fork.
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Affiliation(s)
- Sinny Delacroix
- Department of Molecular Pharmacology and Experimental Therapeutics, Department of Radiation Oncology, and the Division of Oncology Research, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
| | - Jill M. Wagner
- Department of Molecular Pharmacology and Experimental Therapeutics, Department of Radiation Oncology, and the Division of Oncology Research, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
| | - Masahiko Kobayashi
- Department of Molecular Pathology and Cancer Research Institute, Kanazawa University, Kanazawa 920-0934, Japan
| | - Ken-ichi Yamamoto
- Department of Molecular Pathology and Cancer Research Institute, Kanazawa University, Kanazawa 920-0934, Japan
| | - Larry M. Karnitz
- Department of Molecular Pharmacology and Experimental Therapeutics, Department of Radiation Oncology, and the Division of Oncology Research, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
- Corresponding author.E-MAIL ; FAX (507) 284-3906
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24
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Abdu U, Klovstad M, Butin-Israeli V, Bakhrat A, Schüpbach T. An essential role for Drosophila hus1 in somatic and meiotic DNA damage responses. J Cell Sci 2007; 120:1042-9. [PMID: 17327271 PMCID: PMC2791915 DOI: 10.1242/jcs.03414] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The checkpoint proteins Rad9, Rad1 and Hus1 form a clamp-like complex which plays a central role in the DNA-damage-induced checkpoint response. Here we address the function of the 9-1-1 complex in Drosophila. We decided to focus our analysis on the meiotic and somatic requirements of hus1. For that purpose, we created a null allele of hus1 by imprecise excision of a P element found 2 kb from the 3' of the hus1 gene. We found that hus1 mutant flies are viable, but the females are sterile. We determined that hus1 mutant flies are sensitive to hydroxyurea and methyl methanesulfonate but not to X-rays, suggesting that hus1 is required for the activation of an S-phase checkpoint. We also found that hus1 is not required for the G2-M checkpoint and for post-irradiation induction of apoptosis. We subsequently studied the role of hus1 in activation of the meiotic checkpoint and found that the hus1 mutation suppresses the dorsal-ventral pattering defects caused by mutants in DNA repair enzymes. Interestingly, we found that the hus1 mutant exhibits similar oocyte nuclear defects as those produced by mutations in DNA repair enzymes. These results demonstrate that hus1 is essential for the activation of the meiotic checkpoint and that hus1 is also required for the organization of the oocyte DNA, a function that might be independent of the meiotic checkpoint.
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Affiliation(s)
- Uri Abdu
- Department of Life Sciences, National Institute for Biotechnology in the Negev, Ben-Gurion University, Beer-Sheva, 84105, Israel.
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25
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Brandt PD, Helt CE, Keng PC, Bambara RA. The Rad9 protein enhances survival and promotes DNA repair following exposure to ionizing radiation. Biochem Biophys Res Commun 2006; 347:232-7. [PMID: 16814252 DOI: 10.1016/j.bbrc.2006.06.064] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Accepted: 06/13/2006] [Indexed: 10/24/2022]
Abstract
Following DNA damage cells initiate cell cycle checkpoints to allow time to repair sustained lesions. Rad9, Rad1, and Hus1 proteins form a toroidal complex, termed the 9-1-1 complex, that is involved in checkpoint signaling. 9-1-1 shares high structural similarity to the DNA replication protein proliferating cell nuclear antigen (PCNA) and 9-1-1 has been shown in vitro to stimulate steps of the repair process known as long patch base excision repair. Using a system that allows conditional repression of the Rad9 protein in human cell culture, we show that Rad9, and by extension, the 9-1-1 complex, enhances cell survival, is required for efficient exit from G2-phase arrest, and stimulates the repair of damaged DNA following ionizing radiation. These data provide in vivo evidence that the human 9-1-1 complex participates in DNA repair in addition to its previously described role in DNA damage sensing.
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Affiliation(s)
- Patrick D Brandt
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, The University of Rochester, NY 14642, USA
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26
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Rossi ML, Purohit V, Brandt PD, Bambara RA. Lagging strand replication proteins in genome stability and DNA repair. Chem Rev 2006; 106:453-73. [PMID: 16464014 DOI: 10.1021/cr040497l] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Marie L Rossi
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, New York 14642, USA
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27
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Jiang G, Sancar A. Recruitment of DNA damage checkpoint proteins to damage in transcribed and nontranscribed sequences. Mol Cell Biol 2006; 26:39-49. [PMID: 16354678 PMCID: PMC1317637 DOI: 10.1128/mcb.26.1.39-49.2006] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We developed a chromatin immunoprecipitation method for analyzing the binding of repair and checkpoint proteins to DNA base lesions in any region of the human genome. Using this method, we investigated the recruitment of DNA damage checkpoint proteins RPA, Rad9, and ATR to base damage induced by UV and acetoxyacetylaminofluorene in transcribed and nontranscribed regions in wild-type and excision repair-deficient human cells in G1 and S phases of the cell cycle. We find that all 3 damage sensors tested assemble at the site or in the vicinity of damage in the absence of DNA replication or repair and that transcription enhances recruitment of checkpoint proteins to the damage site. Furthermore, we find that UV irradiation of human cells defective in excision repair leads to phosphorylation of Chk1 kinase in both G1 and S phase of the cell cycle, suggesting that primary DNA lesions as well as stalled transcription complexes may act as signals to initiate the DNA damage checkpoint response.
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Affiliation(s)
- Guochun Jiang
- Department of Biochemistry and Biophysics, Mary Ellen Jones Building CB 7260, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
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28
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Wang X, Hu B, Weiss RS, Wang Y. The effect of Hus1 on ionizing radiation sensitivity is associated with homologous recombination repair but is independent of nonhomologous end-joining. Oncogene 2006; 25:1980-3. [PMID: 16278671 DOI: 10.1038/sj.onc.1209212] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mammalian Hus1 plays an important role in maintaining genomic integrity. Cells lacking mouse Hus1 are hypersensitive to DNA damage inducers including UV and camptothecin (CPT). By using clonogenic assay, we show here that Hus1 deficient mouse cells are hypersensitive to ionizing radiation (IR) compared with their Hus1-positive counterparts. However, these cells show similar induction levels and similar rejoining rates of DNA double strand breaks (DSBs) following IR, indicating that the effect of Hus1 on cell radiosensitivity is independent of nonhomologous end-joining (NHEJ). By combining an I-SceI-induced-DNA DSBs system and a siRNA approach, we also show that knocking down Hus1 decreases the efficiency of homologous recombination repair (HRR), which is associated with the cellular sensitivity to IR-induced killing. Together, these results indicate that the role of Hus1 affecting the sensitivity of cells to IR-induced killing is independent of NHEJ but might be linked to HRR.
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Affiliation(s)
- X Wang
- Department of Radiation Oncology and Kimmel Cancer Center of Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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29
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Mammalian DNA damage response pathway. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 570:425-55. [PMID: 18727510 DOI: 10.1007/1-4020-3764-3_15] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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30
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Cheng CK, Chow LWC, Loo WTY, Chan TK, Chan V. The cell cycle checkpoint gene Rad9 is a novel oncogene activated by 11q13 amplification and DNA methylation in breast cancer. Cancer Res 2005; 65:8646-54. [PMID: 16204032 DOI: 10.1158/0008-5472.can-04-4243] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Human Rad9 (hRad9), a structural homologue of yeast Schizosaccharomyces pombe rad9, is involved in cell cycle checkpoints and apoptosis. hRad9 can serve as a corepressor of androgen receptor in prostate cancer cells, but little is known about its role in the development of breast or other cancers. In the present study, semiquantitative reverse transcription-PCR showed that Rad9 mRNA levels were up-regulated in 52.1% (25 of 48) of breast tumors, and this up-regulation correlated with tumor size (P = 0.037) and local recurrence (P = 0.033). Overexpression of Rad9 mRNA was partly due to an increase in Rad9 gene number as measured by quantitative PCR. In other breast tumors with Rad9 mRNA overexpression but without increase in gene number, there was differential methylation of two putative Sp1/3 binding sites within the first and second introns of the Rad9 gene, which was similarly found in MCF-7 breast cancer cell line with increased Rad9 mRNA. Silencing Rad9 expression by RNA interference in MCF-7 cell line inhibited its proliferation in vitro. Promoter assays indicated that the Sp1/3 site in intron 2 may act as a silencer. In vivo binding of Sp3 to intron 2 was shown by chromatin immunoprecipitation assays. Treatment of MCF-7 cell line with 5'-aza-2'-deoxycytidine reduced Rad9 mRNA expression and also increased binding of Sp3 to the demethylated intron 2 region. Collectively, these findings suggest that Rad9 is a novel oncogene candidate activated by 11q13 amplification and DNA hypermethylation in breast cancer and may play a role in tumor proliferation and local invasion.
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MESH Headings
- Azacitidine/analogs & derivatives
- Azacitidine/pharmacology
- Base Sequence
- Breast Neoplasms/genetics
- Breast Neoplasms/metabolism
- Breast Neoplasms/pathology
- Breast Neoplasms, Male/genetics
- Breast Neoplasms, Male/metabolism
- Breast Neoplasms, Male/pathology
- Cell Cycle Proteins/antagonists & inhibitors
- Cell Cycle Proteins/biosynthesis
- Cell Cycle Proteins/genetics
- Cell Growth Processes/genetics
- Cell Line, Tumor
- Chromosomes, Human, Pair 11/genetics
- Cyclin D1/genetics
- DNA Methylation
- Decitabine
- Female
- Gene Amplification
- Gene Expression Regulation, Neoplastic
- Gene Silencing
- Humans
- Introns
- Male
- Middle Aged
- Molecular Sequence Data
- RNA, Messenger/antagonists & inhibitors
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
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Affiliation(s)
- Chi Keung Cheng
- University Department of Medicine, Queen Mary Hospital, Pokfulam, Hong Kong, China
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31
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Majka J, Burgers PM. Function of Rad17/Mec3/Ddc1 and its partial complexes in the DNA damage checkpoint. DNA Repair (Amst) 2005; 4:1189-94. [PMID: 16137930 DOI: 10.1016/j.dnarep.2005.07.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Revised: 07/18/2005] [Accepted: 07/20/2005] [Indexed: 11/18/2022]
Abstract
The Saccharomyces cerevisiae heterotrimeric checkpoint clamp consisting of the Rad17, Mec3, and Ddc1 subunits (Rad17/3/1, the 9-1-1 complex in humans) is an early response factor to DNA damage in a signal transduction pathway leading to the activation of the checkpoint system and eventually to cell cycle arrest. These subunits show structural similarities with the replication clamp PCNA and indeed, it was demonstrated in vitro that Rad17/3/1 could be loaded onto DNA by checkpoint specific clamp loader Rad24-RFC, analogous to the PCNA-RFC clamp-clamp loader system. We have studied the interactions between the checkpoint clamp subunits and the activity of partial clamp complexes. We find that none of the possible partial complexes makes up a clamp that can be loaded onto DNA by Rad24-RFC. In agreement, overexpression of DDC1 or RAD17 in a MEC3Delta strain, or of MEC3 or RAD17 in a DDC1Delta strain shows no rescue of damage sensitivity.
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Affiliation(s)
- Jerzy Majka
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
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32
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Wu X, Shell SM, Zou Y. Interaction and colocalization of Rad9/Rad1/Hus1 checkpoint complex with replication protein A in human cells. Oncogene 2005; 24:4728-35. [PMID: 15897895 PMCID: PMC1447597 DOI: 10.1038/sj.onc.1208674] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2005] [Revised: 02/16/2005] [Accepted: 02/17/2005] [Indexed: 11/08/2022]
Abstract
Replication protein A (RPA) is a eukaryotic single-stranded DNA-binding protein consisting of three subunits of 70-, 32-, and 14-kDa (RPA70, RPA32, RPA14, respectively). It is a protein essential for most cellular DNA metabolic pathways. Checkpoint proteins Rad9, Rad1, and Hus1 form a clamp-like complex which plays a central role in the DNA damage-induced checkpoint response. In this report, we presented the evidence that Rad9-Rad1-Hus1 (9-1-1) complex directly interacted with RPA in human cells, and this interaction was mediated by the binding of Rad9 protein to both RPA70 and RPA32 subunits. In addition, the cellular interaction of 9-1-1 with RPA or hyperphosphorylated RPA was stimulated by UV irradiation or camptothecin treatment in a dose-dependent manner. Such treatments also resulted in the colocalization of the nuclear foci formed with the two complexes. Consistently, knockdown of the RPA expression in cells by the small interference RNA (siRNA) blocked the DNA damage-dependent chromatin association of 9-1-1, and also inhibited the 9-1-1 complex formation. Taken together, our results suggest that 9-1-1 and RPA complexes collaboratively function in DNA damage responses, and that the RPA may serve as a regulator for the activity of 9-1-1 complex in the cellular checkpoint network.
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Affiliation(s)
- Xiaoming Wu
- Department of Biochemistry and Molecular Biology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee 37614
| | - Steven M. Shell
- Department of Biochemistry and Molecular Biology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee 37614
| | - Yue Zou
- Department of Biochemistry and Molecular Biology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee 37614
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33
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Bi X, Slater DM, Ohmori H, Vaziri C. DNA polymerase kappa is specifically required for recovery from the benzo[a]pyrene-dihydrodiol epoxide (BPDE)-induced S-phase checkpoint. J Biol Chem 2005; 280:22343-55. [PMID: 15817457 DOI: 10.1074/jbc.m501562200] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Previously we identified an intra-S-phase cell cycle checkpoint elicited by the DNA-damaging carcinogen benzo[a]pyrene-dihydrodiol epoxide (BPDE). Here we have investigated the roles of lesion bypass DNA polymerases polkappa and poleta in the BPDE-induced S-phase checkpoint. BPDE treatment induced the re-localization of an ectopically expressed green fluorescent protein-polkappa fusion protein to nuclear foci containing sites of active DNA synthesis in human lung carcinoma H1299 cells. In contrast, a similarly expressed yellow fluorescent protein-poleta fusion protein showed a constitutive nuclear focal distribution at replication forks (in the same cells) that was unchanged in response to BPDE. BPDE-induced formation of green fluorescent protein-polkappa nuclear foci was temporally coincident with checkpoint-mediated S-phase arrest. Unlike "wild-type" cells, Polk(-/-) mouse embryonic fibroblasts (MEFs) failed to recover from BPDE-induced S-phase arrest, while exhibiting normal recovery from S-phase arrest induced by ionizing radiation and hydroxyurea. XPV fibroblasts lacking poleta showed a normal S-phase checkpoint response to BPDE (but failed to recover from the UV light-induced S-phase checkpoint), in sharp contrast to Polk(-/-) MEFs. The persistent S-phase arrest in BPDE-treated Polk(-/-) cells was associated with increased levels of histone gammaH2AX (a marker of DNA double-strand breaks (DSBs)) and activation of the DSB-responsive kinases ATM and Chk2. These data suggest that in the absence of polkappa, replication forks stall at sites of damage and collapse and generate DSBs. Therefore, we conclude that the trans-lesion synthesis enzyme polkappa is specifically required for normal recovery from the BPDE-induced S-phase checkpoint.
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Affiliation(s)
- Xiaohui Bi
- Department of Genetics and Genomics, Boston University School of Medicine, 80 E. Concord Street, Boston, MA 02118, USA
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34
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Sabourin CLK, Rogers JV, Choi YW, Kiser RC, Casillas RP, Babin MC, Schlager JJ. Time- and dose-dependent analysis of gene expression using microarrays in sulfur mustard-exposed mice. J Biochem Mol Toxicol 2005; 18:300-12. [PMID: 15674844 DOI: 10.1002/jbt.20047] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The chemical warfare agent sulfur mustard (SM) produces blister formation with a severe inflammatory reaction in skin of exposed individuals. The development of efficacious countermeasures against SM vesication requires an understanding of the cellular and molecular mechanism of SM-induced tissue injury. This study examined SM-induced alterations in gene expression using Atlas Mouse 5K DNA microarrays (5002 genes) to identify transcriptional events associated with SM skin injury. Mice (N=3) were exposed topically to SM (0.04, 0.08, and 0.16 mg; 48.8, 97.5, and 195 mM) on the inner surface of the right ear and skin tissues were harvested at 1.5, 3, 6, and 12 h. Genes were selected based on the three mice in the same dose group demonstrating a > or =2-fold increase or decrease in gene expression for the SM-exposed tissue when compared to the dichloromethane vehicle control ear at all three doses and four time points. At the 0.04 mg SM dose, the genes observed were primarily involved in inflammation, apoptosis, and cell cycle regulation. Exposure to 0.08 mg SM increased the expression of genes related to inflammation and cell cycle regulation. Exposure to 0.16 mg SM led to a total of six genes that were changed at all observed time periods; however, these genes do not appear to be directly influential in biological mechanisms such as inflammation, apoptosis, and cell cycle regulation as was observed at the lower SM doses of 0.04 and 0.08 mg. These functional categories have been observed in previous studies utilizing both in vivo and in vitro model systems of SM-induced dermal injury, suggesting that molecular mechanisms associated with inflammation, apoptosis, and cell cycle regulation may be appropriate targets for developing prophylactic/therapeutic treatments for SM skin injury.
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Affiliation(s)
- Carol L K Sabourin
- Battelle Memorial Institute, Medical Research and Evaluation Facility, Columbus, OH 43201, USA.
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35
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Wang W, Brandt P, Rossi ML, Lindsey-Boltz L, Podust V, Fanning E, Sancar A, Bambara RA. The human Rad9-Rad1-Hus1 checkpoint complex stimulates flap endonuclease 1. Proc Natl Acad Sci U S A 2004; 101:16762-7. [PMID: 15556996 PMCID: PMC534749 DOI: 10.1073/pnas.0407686101] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The toroidal damage checkpoint complex Rad9-Rad1-Hus1 (9-1-1) has been characterized as a sensor of DNA damage. Flap endonuclease 1 (FEN1) is a structure-specific nuclease involved both in removing initiator RNA from Okazaki fragments and in DNA repair pathways. FEN1 activity is stimulated by proliferating cell nuclear antigen (PCNA), a toroidal sliding clamp that acts as a platform for DNA replication and repair complexes. We show that 9-1-1 also binds and stimulates FEN1. Stimulation is observed on a variety of flap, nick, and gapped substrates simulating repair intermediates. Blocking 9-1-1 entry to the double strands prevents a portion of the stimulation. Like PCNA stimulation, 9-1-1 stimulation cannot circumvent the tracking mechanism by which FEN1 enters the substrate; however, 9-1-1 does not substitute for PCNA in the stimulation of DNA polymerase beta. This suggests that 9-1-1 is a damage-specific activator of FEN1.
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Affiliation(s)
- Wensheng Wang
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
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36
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Tsao CC, Geisen C, Abraham RT. Interaction between human MCM7 and Rad17 proteins is required for replication checkpoint signaling. EMBO J 2004; 23:4660-9. [PMID: 15538388 PMCID: PMC533049 DOI: 10.1038/sj.emboj.7600463] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2004] [Accepted: 10/06/2004] [Indexed: 01/09/2023] Open
Abstract
Human Rad17 (hRad17) is centrally involved in the activation of cell-cycle checkpoints by genotoxic agents or replication stress. Here we identify hMCM7, a core component of the DNA replication apparatus, as a novel hRad17-interacting protein. In HeLa cells, depletion of either hRad17 or hMCM7 with small-interfering RNA suppressed ultraviolet (UV) light- or aphidicolin-induced hChk1 phosphorylation, and abolished UV-induced S-phase checkpoint activation. Similar results were obtained after transfection of these cells with a fusion protein containing the hMCM7-binding region of hRad17. The hMCM7-depleted cells were also defective for the formation of ATR-containing nuclear foci after UV irradiation, suggesting that hMCM7 is required for stable recruitment of ATR to damaged DNA. These results demonstrate that hMCM7 plays a direct role in the transmission of DNA damage signals from active replication forks to the S-phase checkpoint machinery in human cells.
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Affiliation(s)
- Cheng-Chung Tsao
- Program in Signal Transduction Research, Cancer Research Center, The Burnham Institute, La Jolla, CA, USA
| | - Christoph Geisen
- Program in Signal Transduction Research, Cancer Research Center, The Burnham Institute, La Jolla, CA, USA
| | - Robert T Abraham
- Program in Signal Transduction Research, Cancer Research Center, The Burnham Institute, La Jolla, CA, USA
- Program in Signal Transduction Research, Cancer Research Center, The Burnham Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA. Tel.: +1 858 646 3182; Fax: +1 858 713 6274; E-mail:
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37
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Hopkins KM, Auerbach W, Wang XY, Hande MP, Hang H, Wolgemuth DJ, Joyner AL, Lieberman HB. Deletion of mouse rad9 causes abnormal cellular responses to DNA damage, genomic instability, and embryonic lethality. Mol Cell Biol 2004; 24:7235-48. [PMID: 15282322 PMCID: PMC479733 DOI: 10.1128/mcb.24.16.7235-7248.2004] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The fission yeast Schizosaccharomyces pombe rad9 gene promotes cell survival through activation of cell cycle checkpoints induced by DNA damage. Mouse embryonic stem cells with a targeted deletion of Mrad9, the mouse ortholog of this gene, were created to evaluate its function in mammals. Mrad9(-/-) cells demonstrated a marked increase in spontaneous chromosome aberrations and HPRT mutations, indicating a role in the maintenance of genomic integrity. These cells were also extremely sensitive to UV light, gamma rays, and hydroxyurea, and heterozygotes were somewhat sensitive to the last two agents relative to Mrad9(+/+) controls. Mrad9(-/-) cells could initiate but not maintain gamma-ray-induced G(2) delay and retained the ability to delay DNA synthesis rapidly after UV irradiation, suggesting that checkpoint abnormalities contribute little to the radiosensitivity observed. Ectopic expression of Mrad9 or human HRAD9 complemented Mrad9(-/-) cell defects, indicating that the gene has radioresponse and genomic maintenance functions that are evolutionarily conserved. Mrad9(+/-) mice were generated, but heterozygous intercrosses failed to yield Mrad9(-/-) pups, since embryos died at midgestation. Furthermore, Mrad9(-/-) mouse embryo fibroblasts were not viable. These investigations establish Mrad9 as a key mammalian genetic element of pathways that regulate the cellular response to DNA damage, maintenance of genomic integrity, and proper embryonic development.
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Affiliation(s)
- Kevin M Hopkins
- Center for Radiological Research, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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38
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Dufault VM, Oestreich AJ, Vroman BT, Karnitz LM. Identification and characterization of RAD9B, a paralog of the RAD9 checkpoint gene. Genomics 2004; 82:644-51. [PMID: 14611806 DOI: 10.1016/s0888-7543(03)00200-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
RAD9 is an integral element of the PCNA-like HUS1-RAD1-RAD9 (9-1-1) complex that participates in genotoxin-induced CHK1 activation. We have identified a novel RAD9 paralog, dubbed RAD9B, in humans and mice. RAD9 and RAD9B share extensive amino acid homology throughout their entire sequences (36% identity, 48% similarity). Northern blotting revealed that RAD9B transcripts are highly expressed in human testes, with lower levels found in skeletal muscle. In contrast, RT-PCR analysis and immunoprecipitation demonstrated that RAD9B is also expressed in tumor cells. Like RAD9, RAD9B associates with HUS1, RAD1, and RAD17, suggesting that it is a RAD9 paralog that engages in similar biochemical reactions. In addition, we have also shown that RAD9 and RAD9B interact with the HUS1 paralog, HUS1B. Taken together, these results suggest that these proteins can combinatorially assemble into distinct 9-1-1 clamps that may have distinct biological functions.
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Affiliation(s)
- Vanessa M Dufault
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic and Foundation, Rochester, MN 55905, USA
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39
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Budzowska M, Jaspers I, Essers J, de Waard H, van Drunen E, Hanada K, Beverloo B, Hendriks RW, de Klein A, Kanaar R, Hoeijmakers JH, Maas A. Mutation of the mouse Rad17 gene leads to embryonic lethality and reveals a role in DNA damage-dependent recombination. EMBO J 2004; 23:3548-58. [PMID: 15297881 PMCID: PMC516625 DOI: 10.1038/sj.emboj.7600353] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2003] [Accepted: 07/13/2004] [Indexed: 01/15/2023] Open
Abstract
Genetic defects in DNA repair mechanisms and cell cycle checkpoint (CCC) genes result in increased genomic instability and cancer predisposition. Discovery of mammalian homologs of yeast CCC genes suggests conservation of checkpoint mechanisms between yeast and mammals. However, the role of many CCC genes in higher eukaryotes remains elusive. Here, we report that targeted deletion of an N-terminal part of mRad17, the mouse homolog of the Schizosaccharomyces pombe Rad17 checkpoint clamp-loader component, resulted in embryonic lethality during early/mid-gestation. In contrast to mouse embryos, embryonic stem (ES) cells, isolated from mRad17(5'Delta/5'Delta) embryos, produced truncated mRad17 and were viable. These cells displayed hypersensitivity to various DNA-damaging agents. Surprisingly, mRad17(5'Delta/5'Delta) ES cells were able to arrest cell cycle progression upon induction of DNA damage. However, they displayed impaired homologous recombination as evidenced by a strongly reduced gene targeting efficiency. In addition to a possible role in DNA damage-induced CCC, based on sequence homology, our results indicate that mRad17 has a function in DNA damage-dependent recombination that may be responsible for the sensitivity to DNA-damaging agents.
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Affiliation(s)
- Magda Budzowska
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
| | - Iris Jaspers
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
| | - Jeroen Essers
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
| | - Harm de Waard
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
| | - Ellen van Drunen
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
| | - Katsuhiro Hanada
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
| | - Berna Beverloo
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
- MGC-Department of Clinical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
| | | | - Annelies de Klein
- MGC-Department of Clinical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
| | - Roland Kanaar
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
- Department of Radiation Oncology, Erasmus MC-Daniel, DR Rotterdam, The Netherlands
| | - Jan H Hoeijmakers
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
| | - Alex Maas
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, DR Rotterdam, The Netherlands
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, PO Box 1738, 3000 DR Rotterdam, The Netherlands. Tel.: +31 10 408 7202; Fax: +31 10 408 9468; E-mail:
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40
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Nabetani A, Yokoyama O, Ishikawa F. Localization of hRad9, hHus1, hRad1, and hRad17 and caffeine-sensitive DNA replication at the alternative lengthening of telomeres-associated promyelocytic leukemia body. J Biol Chem 2004; 279:25849-57. [PMID: 15075340 DOI: 10.1074/jbc.m312652200] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Telomere maintenance is essential for continued cell proliferation. Although most cells accomplish this by activating telomerase, a subset of immortalized tumors and cell lines do so in a telomerase-independent manner, a process called alternative lengthening of telomeres (ALT). DNA recombination has been shown to be involved in ALT, but the precise mechanisms remain unknown. A fraction of cells in a given ALT population contain a unique nuclear structure called APB (ALT-associated promyelocytic leukemia (PML) body), which is characterized by the presence of telomeric DNA in the PML body. Here we describe that hRad9, hHus1, and hRad1, which form a DNA clamp complex that is associated with DNA damage, as well as its clamp loader, hRad17, are constitutive components of APB. Phosphorylated histone H2AX (gamma-H2AX), a molecular marker of double-strand breaks (DSBs), also colocalizes with some APBs. The results suggest that telomeric DNAs at APBs are recognized as DSBs. PML staining and fluorescence in situ hybridization analyses of mitotic ALT cells revealed that telomeric DNAs present at APBs are of both extrachromosomal and native telomere origins. Furthermore, we demonstrated that DNA synthesis occurs at APBs and is significantly inhibited by caffeine, an inhibitor of phosphatidylinositol 3-kinase-related kinases. Taken together, we suggest that telomeric DNAs at APBs are recognized and processed as DSBs, leading to telomeric DNA synthesis and thereby contributing to telomere maintenance in ALT cells.
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Affiliation(s)
- Akira Nabetani
- Department of Gene Mechanisms, Graduate School of Biostudies, Kyoto University, Kitashirakawa Oiwake-cho, Kyoto 606-8502
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41
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Wang L, Hsu CL, Ni J, Wang PH, Yeh S, Keng P, Chang C. Human checkpoint protein hRad9 functions as a negative coregulator to repress androgen receptor transactivation in prostate cancer cells. Mol Cell Biol 2004; 24:2202-13. [PMID: 14966297 PMCID: PMC350564 DOI: 10.1128/mcb.24.5.2202-2213.2004] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Positive responses to combined androgen elimination therapy and radiation therapy have been well documented in the treatment of prostate cancer patients. The detailed mechanisms how androgen-androgen receptor (AR) cross talks to the radiation-related signal pathways, however, remain largely unknown. Here we report the identification of hRad9, a key member of the checkpoint Rad protein family, as a coregulator to suppress androgen-AR transactivation in prostate cancer cells. In vivo and in vitro interaction assays using Saccharomyces cerevisiae two-hybrid, mammalian two-hybrid, glutathione S-transferase pull-down, and coimmunoprecipitation methods prove that AR can interact with the C terminus of hRad9 via its ligand binding domain. The FXXLF motif within the C terminus of hRad9 interrupts the androgen-induced interaction between the N terminus and C terminus of AR. This interaction between AR and hRad9 may result in the suppression of AR transactivation, demonstrated by the repressed AR transactivation in androgen-induced luciferase reporter assay and the reduced endogenous prostate-specific antigen expression in Western blot assay. Addition of small interfering RNA of hRad9 can reverse hRad9 suppression effects, which suggests that hRad9 functions as a repressor of AR transactivation in vivo. Together, our data provide the first linkage between androgen-AR signals and radiation-induced responses. Further studies of the influence of hRad9 on prostate cancer growth may provide potential new therapeutic approaches.
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Affiliation(s)
- Liang Wang
- George H. Whipple Laboratory for Cancer Research, Department of Pathology, University of Rochester Medical Center, Rochester, New York 14642, USA
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42
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Dart DA, Adams KE, Akerman I, Lakin ND. Recruitment of the Cell Cycle Checkpoint Kinase ATR to Chromatin during S-phase. J Biol Chem 2004; 279:16433-40. [PMID: 14871897 DOI: 10.1074/jbc.m314212200] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ataxia telangiectasia-mutated (ATM) and Rad3-related kinase (ATR) is a central component of the cell cycle checkpoint machinery required to induce cell cycle arrest in response to DNA damage. Accumulating evidence suggests a role for ATR in signaling DNA damage during S-phase. Here we show that ATR is recruited to nuclear foci induced by replication fork stalling in a manner that is dependent on the single stranded binding protein replication protein A (RPA). ATR associates with chromatin in asynchronous cell cultures, and we use a variety of approaches to examine the association of ATR with chromatin in the absence of agents that cause genotoxic stress. Under our experimental conditions, ATR exhibits a decreased affinity for chromatin in quiescent cells and cells synchronized at mitosis but an increased affinity for chromatin as cells re-enter the cell cycle. Using centrifugal elutriation to obtain cells enriched at various stages of the cell cycle, we show that ATR associates with chromatin in a cell cycle-dependent manner, specifically during S-phase. Cell cycle association of ATR with chromatin mirrors that of RPA in addition to claspin, a cell cycle checkpoint protein previously shown to be a component of the replication machinery. Furthermore, association of ATR with chromatin occurs in the absence of detectable DNA damage and cell cycle checkpoint activation. These data are consistent with a model whereby ATR is recruited to chromatin during the unperturbed cell cycle and points to a role of ATR in monitoring genome integrity during normal S-phase progression.
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Affiliation(s)
- D Alwyn Dart
- Department of Biochemistry, University of Oxford, South Parks Rd., Oxford OX1 3QU, United Kingdom
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43
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Ma D, McCorkle JR, Kaetzel DM. The metastasis suppressor NM23-H1 possesses 3'-5' exonuclease activity. J Biol Chem 2004; 279:18073-84. [PMID: 14960567 DOI: 10.1074/jbc.m400185200] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
NM23-H1 belongs to a family of eight gene products in humans that have been implicated in cellular differentiation and development, as well as oncogenesis and tumor metastasis. We have defined NM23-H1 biochemically as a 3'-5' exonuclease by virtue of its ability in stoichiometric amounts to excise single nucleotides in a stepwise manner from the 3' terminus of DNA. The activity is dependent upon the presence of Mg(2+), is most pronounced with single-stranded substrates or mismatched bases at the 3' terminus of double-stranded substrates, and is inhibited by both ATP and the incorporation of cordycepin, a 2'-deoxyadenosine analogue, into the 3'-terminal position. The 3'-5' exonuclease activity was assigned to NM23-H1 by virtue of: 1) precise coelution of enzymatic activity with wild-type and mutant forms of NM23-H1 protein during purification by hydroxylapatite and gel filtration column high performance liquid chromatography and 2) significantly diminished activity exhibited by purified recombinant mutant forms of the proteins. Lysine 12 appears to play an important role in the catalytic mechanism, as evidenced by the significant reduction in 3'-5' exonuclease activity resulting from a Lys(12) to glutamine substitution within the protein. 3'-5' Exonucleases are believed to play an important role in DNA repair, a logical candidate function underlying the putative antimetastatic and oncogenic activities of NM23-H1.
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Affiliation(s)
- Deqin Ma
- Department of Molecular and Biomedical Pharmacology, University of Kentucky Medical Center, Lexington, Kentucky 40536-0084, USA
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44
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Abstract
Genome sequences of a number of archaea have revealed an apparent paradox in the phylogenies of the bacteria, archaea, and eukarya, as well as an intriguing set of problems to be resolved in the study of DNA replication. The archaea, long thought to be bacteria, are not only different enough to merit their own domain but also appear to be an interesting mosaic of bacterial, eukaryal, and unique features. Most archaeal proteins participating in DNA replication are more similar in sequence to those found in eukarya than to analogous replication proteins in bacteria. However, archaea have only a subset of the eukaryal replication machinery, apparently needing fewer polypeptides and structurally simpler complexes. The archaeal replication apparatus also contains features not found in other organisms owing, in part, to the broad range of environmental conditions, some extreme, in which members of this domain thrive. In this review the current knowledge of the mechanisms governing DNA replication in archaea is summarized and the similarities and differences of those of bacteria and eukarya are highlighted.
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Affiliation(s)
- Beatrice Grabowski
- University of Maryland Biotechnology Institute, Center for Advanced Research in Biotechnology, 9600 Gudelsky Drive, Rockville, Maryland 20850, USA.
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Wang X, Guan J, Hu B, Weiss RS, Iliakis G, Wang Y. Involvement of Hus1 in the chain elongation step of DNA replication after exposure to camptothecin or ionizing radiation. Nucleic Acids Res 2004; 32:767-75. [PMID: 14762204 PMCID: PMC373359 DOI: 10.1093/nar/gkh243] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Revised: 12/23/2003] [Accepted: 12/23/2003] [Indexed: 11/12/2022] Open
Abstract
DNA damage-induced S phase (S) checkpoint includes inhibition of both replicon initiation and chain elongation. The precise mechanism for controlling the two processes remains unclear. In this study, we showed that Hus1-deficient mouse cells had an impaired S checkpoint after exposure to DNA strand break-inducing agents such as camptothecin (CPT) (>or=1.0 micro M), or ionizing radiation (IR) (>or=15 Gy). The Hus1-dependent S checkpoint contributes to cell resistance to CPT. This impaired S checkpoint induced by CPT or IR in Hus1-deficient cells reflected mainly the chain elongation step of DNA replication and was correlated with the reduction of dissociation of PCNA from DNA replication foci. Although Hus1 is required for Rad9 phosphorylation following exposure of cells to CPT or IR, Hus1-deficient cells showed normal activation of ATR/CHK1 and ATM kinases at doses where the checkpoint defects were manifested, suggesting that Hus1 is not a component of the sensor system for activating these pathways in S checkpoint induced by CPT or IR.
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Affiliation(s)
- Xiang Wang
- Department of Radiation Oncology, Kimmel Cancer Center of Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Majka J, Burgers PMJ. The PCNA-RFC families of DNA clamps and clamp loaders. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2004; 78:227-60. [PMID: 15210332 DOI: 10.1016/s0079-6603(04)78006-x] [Citation(s) in RCA: 240] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The proliferating cell nuclear antigen PCNA functions at multiple levels in directing DNA metabolic pathways. Unbound to DNA, PCNA promotes localization of replication factors with a consensus PCNA-binding domain to replication factories. When bound to DNA, PCNA organizes various proteins involved in DNA replication, DNA repair, DNA modification, and chromatin modeling. Its modification by ubiquitin directs the cellular response to DNA damage. The ring-like PCNA homotrimer encircles double-stranded DNA and slides spontaneously across it. Loading of PCNA onto DNA at template-primer junctions is performed in an ATP-dependent process by replication factor C (RFC), a heteropentameric AAA+ protein complex consisting of the Rfc1, Rfc2, Rfc3, Rfc4, and Rfc5 subunits. Loading of yeast PCNA (POL30) is mechanistically distinct from analogous processes in E. coli (beta subunit by the gamma complex) and bacteriophage T4 (gp45 by gp44/62). Multiple stepwise ATP-binding events to RFC are required to load PCNA onto primed DNA. This stepwise mechanism should permit editing of this process at individual steps and allow for divergence of the default process into more specialized modes. Indeed, alternative RFC complexes consisting of the small RFC subunits together with an alternative Rfc1-like subunit have been identified. A complex required for the DNA damage checkpoint contains the Rad24 subunit, a complex required for sister chromatid cohesion contains the Ctf18 subunit, and a complex that aids in genome stability contains the Elg1 subunit. Only the RFC-Rad24 complex has a known associated clamp, a heterotrimeric complex consisting of Rad17, Mec3, and Ddc1. The other putative clamp loaders could either act on clamps yet to be identified or act on the two known clamps.
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Affiliation(s)
- Jerzy Majka
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Abstract
The human genome, comprising three billion base pairs coding for 30000-40000 genes, is constantly attacked by endogenous reactive metabolites, therapeutic drugs and a plethora of environmental mutagens that impact its integrity. Thus it is obvious that the stability of the genome must be under continuous surveillance. This is accomplished by DNA repair mechanisms, which have evolved to remove or to tolerate pre-cytotoxic, pre-mutagenic and pre-clastogenic DNA lesions in an error-free, or in some cases, error-prone way. Defects in DNA repair give rise to hypersensitivity to DNA-damaging agents, accumulation of mutations in the genome and finally to the development of cancer and various metabolic disorders. The importance of DNA repair is illustrated by DNA repair deficiency and genomic instability syndromes, which are characterised by increased cancer incidence and multiple metabolic alterations. Up to 130 genes have been identified in humans that are associated with DNA repair. This review is aimed at updating our current knowledge of the various repair pathways by providing an overview of DNA-repair genes and the corresponding proteins, participating either directly in DNA repair, or in checkpoint control and signaling of DNA damage.
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Affiliation(s)
- Markus Christmann
- Division of Applied Toxicology, Institute of Toxicology, University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany
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Criswell T, Leskov K, Miyamoto S, Luo G, Boothman DA. Transcription factors activated in mammalian cells after clinically relevant doses of ionizing radiation. Oncogene 2003; 22:5813-27. [PMID: 12947388 DOI: 10.1038/sj.onc.1206680] [Citation(s) in RCA: 197] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Over the past 15 years, a wealth of information has been published on transcripts and proteins 'induced' (requiring new protein synthesis) in mammalian cells after ionizing radiation (IR) exposure. Many of these studies have also attempted to elucidate the transcription factors that are 'activated' (i.e., not requiring de novo synthesis) in specific cells by IR. Unfortunately, all too often this information has been obtained using supralethal doses of IR, with investigators assuming that induction of these proteins, or activation of corresponding transcription factors, can be 'extrapolated' to low-dose IR exposures. This review focuses on what is known at the molecular level about transcription factors induced at clinically relevant (< or =2 Gy) doses of IR. A review of the literature demonstrates that extrapolation from high doses of IR to low doses of IR is inaccurate for most transcription factors and most IR-inducible transcripts/proteins, and that induction of transactivating proteins at low doses must be empirically derived. The signal transduction pathways stimulated after high versus low doses of IR, which act to transactivate certain transcription factors in the cell, will be discussed. To date, only three transcription factors appear to be responsive (i.e. activated) after physiological doses (doses wherein cells survive or recover) of IR. These are p53, nuclear factor kappa B(NF-kappaB), and the SP1-related retinoblastoma control proteins (RCPs). Clearly, more information on transcription factors and proteins induced in mammalian cells at clinically or environmentally relevant doses of IR is needed to understand the role of these stress responses in cancer susceptibility/resistance and radio-sensitivity/resistance mechanisms.
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Affiliation(s)
- Tracy Criswell
- Department of Radiation Oncology and Program in Molecular Basis of Disease, Laboratory of Molecular Stress Responses, Ireland Comprehensive Cancer Center, Case Western Reserve University and University Hospitals of Cleveland, OH 44106-4942, USA
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Jones RE, Chapman JR, Puligilla C, Murray JM, Car AM, Ford CC, Lindsay HD. XRad17 is required for the activation of XChk1 but not XCds1 during checkpoint signaling in Xenopus. Mol Biol Cell 2003; 14:3898-910. [PMID: 12972573 PMCID: PMC196587 DOI: 10.1091/mbc.e03-03-0138] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2003] [Revised: 04/30/2003] [Accepted: 04/30/2003] [Indexed: 12/31/2022] Open
Abstract
The DNA damage/replication checkpoints act by sensing the presence of damaged DNA or stalled replication forks and initiate signaling pathways that arrest cell cycle progression. Here we report the cloning and characterization of Xenopus orthologues of the RFCand PCNA-related checkpoint proteins. XRad17 shares regions of homology with the five subunits of Replication factor C. XRad9, XRad1, and XHus1 (components of the 9-1-1 complex) all show homology to the DNA polymerase processivity factor PCNA. We demonstrate that these proteins associate with chromatin and are phosphorylated when replication is inhibited by aphidicolin. Phosphorylation of X9-1-1 is caffeine sensitive, but the chromatin association of XRad17 and the X9-1-1 complex after replication block is unaffected by caffeine. This suggests that the X9-1-1 complex can associate with chromatin independently of XAtm/XAtr activity. We further demonstrate that XRad17 is essential for the chromatin binding and checkpoint-dependent phosphorylation of X9-1-1 and for the activation of XChk1 when the replication checkpoint is induced by aphidicolin. XRad17 is not, however, required for the activation of XCds1 in response to dsDNA ends.
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Affiliation(s)
- Rhiannon E Jones
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton, BN19RQ, United Kingdom.
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Merkle CJ, Karnitz LM, Henry-Sánchez JT, Chen J. Cloning and characterization of hCTF18, hCTF8, and hDCC1. Human homologs of a Saccharomyces cerevisiae complex involved in sister chromatid cohesion establishment. J Biol Chem 2003; 278:30051-6. [PMID: 12766176 DOI: 10.1074/jbc.m211591200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A growing body of evidence suggests that establishment of sister chromatid cohesion is dependent on replication fork passage over a precohesion area. In Saccharomyces cerevisiae, this process involves an alternative replication factor C (RFC) complex that contains the four small RFC subunits as well as CTF18, CTF8, and DCC1. Here, we show that an evolutionarily conserved homologous complex exists in the nucleus of human cells. We demonstrate that hCTF18, hCTF8, and hDCC1 interact with each other as well as with the p38 subunit of RFC. This alternative RFC-containing complex interacts with proliferating cell nuclear antigen but not with the Rad9/Rad1/Hus1 complex, a proliferating cell nuclear antigen-like clamp involved in the DNA damage response. hCTF18 preferentially binds chromatin during S phase, suggesting a role during replication. Our data provide evidence for the existence of an alternative RFC complex with a probable role in mammalian sister chromatid cohesion establishment.
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Affiliation(s)
- Carolin J Merkle
- Graduate Program in Tumor Biology, Mayo Graduate School, Rochester, Minnesota 55905, USA
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