1
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Zhou X, Li S, Yang X. The DcPS1 cooperates with OSDLa during pollen development and 2n gamete production in carnation meiosis. BMC PLANT BIOLOGY 2022; 22:259. [PMID: 35610560 PMCID: PMC9128087 DOI: 10.1186/s12870-022-03648-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/09/2022] [Indexed: 05/31/2023]
Abstract
BACKGROUND Deciphering the mechanisms of meiosis has important implications for potential applications in plant breeding programmes and species evolution. However, the process of meiosis is poorly understood in carnation, which is famous for its cut flowers. RESULTS We report that Dianthus caryophyllus parallel spindle 1 (DcPS1) regulates omission of second division like a (OSDLa) during pollen development and 2n gamete production in carnation meiosis. In DcPS1 and OSDLa RNAi lines, an absence of the second meiotic division and the abnormal orientation of spindles at meiosis II might be the main reason for dyad/triad formation, resulting in unreduced gametes. We also found that carnation OSDLa interacted with DcPS1 and DcRAD51D. In the DcPS1 RNAi lines, a decrease in OSDLa and DcRAD51D expression was observed. In the OSDLa RNAi lines, a decrease in DcPS1 and DcRAD51D expression was also observed. We propose that DcPS1 regulates OSDLa expression, allowing entry into meiosis II and the proper orientation of the metaphase II spindle in meiosis II. We also propose that OSDLa regulates DcRAD51D expression, allowing for homologous recombination. CONCLUSIONS These results suggest a critical role for DcPS1 and OSDLa in diplogamete production during meiosis and open a new pathway for meiosis-related studies.
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Affiliation(s)
- Xuhong Zhou
- Office of Science and Technology, Yunnan University of Chinese Medicine, 1076 Yuhua Road, Chenggong, Kunming, Yunnan, 650500, PR China.
- Flower Research Institute, Yunnan Academy of Agricultural Sciences, National Engineering Research Center for Ornamental Horticulture, 2238 Beijing Road, Kunming, Yunnan, 650205, PR China.
| | - Shuying Li
- Flower Research Institute, Yunnan Academy of Agricultural Sciences, National Engineering Research Center for Ornamental Horticulture, 2238 Beijing Road, Kunming, Yunnan, 650205, PR China
| | - Xiaomi Yang
- Office of Science and Technology, Yunnan University of Chinese Medicine, 1076 Yuhua Road, Chenggong, Kunming, Yunnan, 650500, PR China
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2
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Boni J, Idani A, Roca C, Feliubadaló L, Tomiak E, Weber E, Foulkes WD, Orthwein A, El Haffaf Z, Lazaro C, Rivera B. A decade of RAD51C and RAD51D germline variants in cancer. Hum Mutat 2021; 43:285-298. [PMID: 34923718 DOI: 10.1002/humu.24319] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/08/2021] [Accepted: 12/15/2021] [Indexed: 11/12/2022]
Abstract
Defects in DNA repair genes have been extensively associated with cancer susceptibility. Germline pathogenic variants (GPV) in genes involved in homologous recombination repair pathways predispose to cancers arising mainly in the breast and ovary, but also other tissues. The RAD51 paralogs RAD51C and RAD51D were included in this group 10 years ago when germline variants were associated with non-BRCA1/2 familial ovarian cancer. Here, we have reviewed the landscape of RAD51C and RAD51D germline variants in cancer reported in the literature during the last decade, integrating this list with variants identified by in-house patient screening. A comprehensive catalog of 341 variants that have been classified applying ACMG/AMP criteria has been generated pinpointing the existence of recurrent variants in both genes. Recurrent variants have been extensively discussed compiling data on population frequencies and functional characterization if available, highlighting variants that have not been fully characterized yet to properly establish their pathogenicity. Finally, we have complemented this data with relevant information regarding the conservation of mutated residues among RAD51 paralogs and modeling of putative hotspot areas, which contributes to generating an exhaustive update on these two cancer predisposition genes.
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Affiliation(s)
- Jacopo Boni
- Program in Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell), Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain
| | - Aida Idani
- Program in Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell), Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain
| | - Carla Roca
- Program in Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell), Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain
| | - Lidia Feliubadaló
- Hereditary Cancer Program, Catalan Institute of Oncology, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain
| | - Eva Tomiak
- Department of Genetics, University of Ottawa, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Evan Weber
- Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Quebec, Montreal, Canada
| | - William D Foulkes
- Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Quebec, Montreal, Canada.,Gerald Bronfman Department of Oncology, McGill University Montreal, Montreal, Quebec, Canada.,Department of Human Genetics, McGill University Montreal, Montreal, Quebec, Canada.,Cancer Research Axis, Lady Davis Institute, Jewish General Hospital, Quebec, Montreal, Canada
| | - Alexandre Orthwein
- Gerald Bronfman Department of Oncology, McGill University Montreal, Montreal, Quebec, Canada.,Cancer Research Axis, Lady Davis Institute, Jewish General Hospital, Quebec, Montreal, Canada
| | - Zaki El Haffaf
- Division of Genetics, Department of Medicine, Research Center, Centre Hospitalier de l'Université de Montréal (CRCHUM), Quebec, Montreal, Canada
| | - Conxi Lazaro
- Program in Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell), Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain.,Hereditary Cancer Program, Catalan Institute of Oncology, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain
| | - Barbara Rivera
- Program in Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell), Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain.,Hereditary Cancer Program, Catalan Institute of Oncology, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain.,Gerald Bronfman Department of Oncology, McGill University Montreal, Montreal, Quebec, Canada.,Cancer Research Axis, Lady Davis Institute, Jewish General Hospital, Quebec, Montreal, Canada
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3
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Bueno-Martínez E, Sanoguera-Miralles L, Valenzuela-Palomo A, Lorca V, Gómez-Sanz A, Carvalho S, Allen J, Infante M, Pérez-Segura P, Lázaro C, Easton DF, Devilee P, Vreeswijk MPG, de la Hoya M, Velasco EA. RAD51D Aberrant Splicing in Breast Cancer: Identification of Splicing Regulatory Elements and Minigene-Based Evaluation of 53 DNA Variants. Cancers (Basel) 2021; 13:2845. [PMID: 34200360 PMCID: PMC8201001 DOI: 10.3390/cancers13112845] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/01/2021] [Accepted: 06/03/2021] [Indexed: 12/18/2022] Open
Abstract
RAD51D loss-of-function variants increase lifetime risk of breast and ovarian cancer. Splicing disruption is a frequent pathogenic mechanism associated with variants in susceptibility genes. Herein, we have assessed the splicing and clinical impact of splice-site and exonic splicing enhancer (ESE) variants identified through the study of ~113,000 women of the BRIDGES cohort. A RAD51D minigene with exons 2-9 was constructed in splicing vector pSAD. Eleven BRIDGES splice-site variants (selected by MaxEntScan) were introduced into the minigene by site-directed mutagenesis and tested in MCF-7 cells. The 11 variants disrupted splicing, collectively generating 25 different aberrant transcripts. All variants but one produced negligible levels (<3.4%) of the full-length (FL) transcript. In addition, ESE elements of the alternative exon 3 were mapped by testing four overlapping exonic microdeletions (≥30-bp), revealing an ESE-rich interval (c.202_235del) with critical sequences for exon 3 recognition that might have been affected by germline variants. Next, 26 BRIDGES variants and 16 artificial exon 3 single-nucleotide substitutions were also assayed. Thirty variants impaired splicing with variable amounts (0-65.1%) of the FL transcript, although only c.202G>A demonstrated a complete aberrant splicing pattern without the FL transcript. On the other hand, c.214T>C increased efficiency of exon 3 recognition, so only the FL transcript was detected (100%). In conclusion, 41 RAD51D spliceogenic variants (28 of which were from the BRIDGES cohort) were identified by minigene assays. We show that minigene-based mapping of ESEs is a powerful approach for identifying ESE hotspots and ESE-disrupting variants. Finally, we have classified nine variants as likely pathogenic according to ACMG/AMP-based guidelines, highlighting the complex relationship between splicing alterations and variant interpretation.
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Affiliation(s)
- Elena Bueno-Martínez
- Splicing and Genetic Susceptibility to Cancer Laboratory, Unidad de Excelencia Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC-UVa), 47003 Valladolid, Spain; (E.B.-M.); (L.S.-M.); (A.V.-P.)
| | - Lara Sanoguera-Miralles
- Splicing and Genetic Susceptibility to Cancer Laboratory, Unidad de Excelencia Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC-UVa), 47003 Valladolid, Spain; (E.B.-M.); (L.S.-M.); (A.V.-P.)
| | - Alberto Valenzuela-Palomo
- Splicing and Genetic Susceptibility to Cancer Laboratory, Unidad de Excelencia Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC-UVa), 47003 Valladolid, Spain; (E.B.-M.); (L.S.-M.); (A.V.-P.)
| | - Víctor Lorca
- Molecular Oncology Laboratory CIBERONC, IdISSC (Instituto de Investigación Sanitaria del Hospital Clínico San Carlos), Hospital Clinico San Carlos, 28040 Madrid, Spain; (V.L.); (A.G.-S.); (P.P.-S.)
| | - Alicia Gómez-Sanz
- Molecular Oncology Laboratory CIBERONC, IdISSC (Instituto de Investigación Sanitaria del Hospital Clínico San Carlos), Hospital Clinico San Carlos, 28040 Madrid, Spain; (V.L.); (A.G.-S.); (P.P.-S.)
| | - Sara Carvalho
- Centre for Cancer Genetic Epidemiology, Department of Public Health and Primary Care, University of Cambridge, Cambridge CB1 8RN, UK; (S.C.); (J.A.); (D.F.E.)
| | - Jamie Allen
- Centre for Cancer Genetic Epidemiology, Department of Public Health and Primary Care, University of Cambridge, Cambridge CB1 8RN, UK; (S.C.); (J.A.); (D.F.E.)
| | - Mar Infante
- Cancer Genetics, Unidad de Excelencia Instituto de Biología y Genética Molecular (CSIC-UVa), 47003 Valladolid, Spain;
| | - Pedro Pérez-Segura
- Molecular Oncology Laboratory CIBERONC, IdISSC (Instituto de Investigación Sanitaria del Hospital Clínico San Carlos), Hospital Clinico San Carlos, 28040 Madrid, Spain; (V.L.); (A.G.-S.); (P.P.-S.)
| | - Conxi Lázaro
- Hereditary Cancer Program, Catalan Institute of Oncology, IDIBELL and CIBERONC, 08908 Hospitalet de Llobregat, Spain;
| | - Douglas F. Easton
- Centre for Cancer Genetic Epidemiology, Department of Public Health and Primary Care, University of Cambridge, Cambridge CB1 8RN, UK; (S.C.); (J.A.); (D.F.E.)
| | - Peter Devilee
- Department of Human Genetics, Leiden University Medical Center, 2300RC Leiden, The Netherlands; (P.D.); (M.P.G.V.)
| | - Maaike P. G. Vreeswijk
- Department of Human Genetics, Leiden University Medical Center, 2300RC Leiden, The Netherlands; (P.D.); (M.P.G.V.)
| | - Miguel de la Hoya
- Molecular Oncology Laboratory CIBERONC, IdISSC (Instituto de Investigación Sanitaria del Hospital Clínico San Carlos), Hospital Clinico San Carlos, 28040 Madrid, Spain; (V.L.); (A.G.-S.); (P.P.-S.)
| | - Eladio A. Velasco
- Splicing and Genetic Susceptibility to Cancer Laboratory, Unidad de Excelencia Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC-UVa), 47003 Valladolid, Spain; (E.B.-M.); (L.S.-M.); (A.V.-P.)
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4
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Wappenschmidt B, Hauke J, Faust U, Niederacher D, Wiesmüller L, Schmidt G, Groß E, Gehrig A, Sutter C, Ramser J, Rump A, Arnold N, Meindl A. Criteria of the German Consortium for Hereditary Breast and Ovarian Cancer for the Classification of Germline Sequence Variants in Risk Genes for Hereditary Breast and Ovarian Cancer. Geburtshilfe Frauenheilkd 2020; 80:410-429. [PMID: 32322110 PMCID: PMC7174002 DOI: 10.1055/a-1110-0909] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/28/2020] [Accepted: 01/29/2020] [Indexed: 12/14/2022] Open
Abstract
More than ten years ago, the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC) set up a panel of experts (VUS Task Force) which was tasked with reviewing the classifications of genetic variants reported by individual centres of the GC-HBOC to the central database in Leipzig and reclassifying them, where necessary, based on the most recent data. When it evaluates variants, the VUS Task Force must arrive at a consensus. The resulting classifications are recorded in a central database where they serve as a basis for ensuring the consistent evaluation of previously known and newly identified variants in the different centres of the GC-HBOC. The standardised VUS evaluation by the VUS Task Force is a key element of the recall system which has also been set up by the GC-HBOC. The system will be used to pass on information to families monitored and managed by GC-HBOC centres in the event that previously classified variants are reclassified based on new information. The evaluation algorithm of the VUS Task Force was compiled using internationally established assessment methods (IARC, ACMG, ENIGMA) and is presented here together with the underlying evaluation criteria used to arrive at the classification decision using a flow chart. In addition, the characteristics and special features of specific individual risk genes associated with breast and/or ovarian cancer are discussed in separate subsections. The URLs of relevant databases have also been included together with extensive literature references to provide additional information and cover the scope and dynamism of the current state of knowledge on the evaluation of genetic variants. In future, if criteria are updated based on new information, the update will be published on the website of the GC-HBOC (
https://www.konsortium-familiaerer-brustkrebs.de/
).
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Affiliation(s)
- Barbara Wappenschmidt
- Zentrum familiärer Brust- und Eierstockkrebs, Universitätsklinikum Köln, Köln, Germany
| | - Jan Hauke
- Zentrum familiärer Brust- und Eierstockkrebs, Universitätsklinikum Köln, Köln, Germany
| | - Ulrike Faust
- Institut für Medizinische Genetik und Angewandte Genomik, Universität Tübingen, Tübingen, Germany
| | - Dieter Niederacher
- Klinik für Frauenheilkunde und Geburtshilfe, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Lisa Wiesmüller
- Frauenklinik, Sektion Gynäkologische Onkologie, Uniklinik Ulm, Ulm, Germany
| | - Gunnar Schmidt
- Institut für Humangenetik, Medizinische Hochschule Hannover, Hannover, Germany
| | - Evi Groß
- Klinik und Poliklinik für Frauenheilkunde und Geburtshilfe, Klinikum der Universität München, Campus Großhadern, München, Germany
| | - Andrea Gehrig
- Institut für Humangenetik, Universität Würzburg, Würzburg, Germany
| | - Christian Sutter
- Institut für Humangenetik, Universität Heidelberg, Heidelberg, Germany
| | - Juliane Ramser
- Frauenklinik der Technischen Universität München, Klinikum rechts der Isar, München, Germany
| | - Andreas Rump
- Institut für klinische Genetik, Technische Universität Dresden, Dresden, Germany
| | - Norbert Arnold
- Universitätsklinikum Kiel, Klinik für Gynäkologie und Geburtshilfe, Kiel, Germany.,Institut für Klinische Molekularbiologie, Universitätsklinikum Kiel, Kiel, Germany
| | - Alfons Meindl
- Klinik und Poliklinik für Frauenheilkunde und Geburtshilfe, Klinikum der Universität München, Campus Großhadern, München, Germany.,Frauenklinik der Technischen Universität München, Klinikum rechts der Isar, München, Germany
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5
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A Mammalian Genetic Complementation Assay for Assessing Cellular Resistance to Genotoxic Compounds. Methods Mol Biol 2019. [PMID: 31127578 DOI: 10.1007/978-1-4939-9500-4_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
A complementation assay was developed to determine whether alleles of DNA repair genes are necessary for repairing specific types of damage. The assay was established by measuring the resistance capacity of Rad51d-deficient mouse embryonic fibroblasts (MEFs) transfected with mammalian expression constructs. Here, we describe the methods used to assess colony survival following the treatment of transfected cells with genotoxic compounds. This approach provides a time-efficient and stringent strategy to screen genetic alleles for identifying regions or specific amino acid residues critical for function or regulation of DNA repair pathways.
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6
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RAD51D splice variants and cancer-associated mutations reveal XRCC2 interaction to be critical for homologous recombination. DNA Repair (Amst) 2019; 76:99-107. [PMID: 30836272 DOI: 10.1016/j.dnarep.2019.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 02/15/2019] [Accepted: 02/15/2019] [Indexed: 12/14/2022]
Abstract
The proficiency of cancer cells to repair DNA double-strand breaks (DSBs) by homologous recombination (HR) is a key determinant in predicting response to targeted therapies such as PARP inhibitors. The RAD51 paralogs work as multimeric complexes and act downstream of BRCA1 to facilitate HR. Numerous epidemiological studies have linked RAD51 paralog mutations with hereditary cancer predisposition. Despite their substantial links to cancer, RAD51 paralog HR function has remained elusive. Here we identify isoform 1 as the functional isoform of RAD51D, whereas isoform 4 which has a large N-terminal deletion (including the Walker A motif), and isoform 6 which includes an alternate exon in the N-terminus, are non-functional. To determine the importance of this N-terminal region, we investigated the impact of cancer-associated mutations and SNPs in this variable RAD51D N-terminal region using yeast-2-hybrid and yeast-3-hybrid assays to screen for altered protein-protein interactions. We identified two cancer-associated mutations close to or within the Walker A motif (G96C and G107 V, respectively) that independently disrupt RAD51D interaction with XRCC2. We validated our yeast interaction data in human U2OS cells by co-immunoprecipitation and determined the impact of these mutations on HR-proficiency using a sister chromatid recombination reporter assay in a RAD51D knock-out cell line. Our investigation reveals that the interaction of RAD51D with XRCC2 is required for DSB repair. By characterizing the impact of cancer-associated mutations on RAD51D interactions, we aim to develop predictive models for therapeutic sensitivity and resistance in patients who harbor similar mutations in RAD51D.
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7
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Reilly NM, Yard BD, Pittman DL. Homologous Recombination-Mediated DNA Repair and Implications for Clinical Treatment of Repair Defective Cancers. Methods Mol Biol 2019; 1999:3-29. [PMID: 31127567 DOI: 10.1007/978-1-4939-9500-4_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Double-strand DNA breaks (DSBs) are generated by ionizing radiation and as intermediates during the processing of DNA, such as repair of interstrand cross-links and collapsed replication forks. These potentially deleterious DSBs are repaired primarily by the homologous recombination (HR) and nonhomologous end joining (NHEJ) DNA repair pathways. HR utilizes a homologous template to accurately restore damaged DNA, whereas NHEJ utilizes microhomology to join breaks in close proximity. The pathway available for DSB repair is dependent upon the cell cycle stage; for example, HR primarily functions during the S/G2 stages while NHEJ can repair DSBs at any cell cycle stage. Posttranslational modifications (PTMs) promote activity of specific pathways and subpathways through enzyme activation and precisely timed protein recruitment and degradation. This chapter provides an overview of PTMs occurring during DSB repair. In addition, clinical phenotypes associated with HR-defective cancers, such as mutational signatures used to predict response to poly(ADP-ribose) polymerase inhibitors, are discussed. Understanding these processes will provide insight into mechanisms of genome maintenance and likely identify targets and new avenues for therapeutic interventions.
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Affiliation(s)
- Nicole M Reilly
- Fondazione Piemontese per la Ricerca sul Cancro ONLUS, Candiolo, Italy
| | - Brian D Yard
- Department of Translational Hematology and Oncology Research, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Douglas L Pittman
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA.
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8
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Harris JL, Rabellino A, Khanna KK. RAD51 paralogs promote genomic integrity and chemoresistance in cancer by facilitating homologous recombination. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:S122. [PMID: 30740443 DOI: 10.21037/atm.2018.12.30] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Andrea Rabellino
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Kum Kum Khanna
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
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9
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Alayev A, Salamon RS, Manna S, Schwartz NS, Berman AY, Holz MK. Estrogen induces RAD51C expression and localization to sites of DNA damage. Cell Cycle 2016; 15:3230-3239. [PMID: 27753535 DOI: 10.1080/15384101.2016.1241927] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Homologous recombination (HR) is a conserved process that maintains genome stability and cell survival by repairing DNA double-strand breaks (DSBs). The RAD51-related family of proteins is involved in repair of DSBs; consequently, deregulation of RAD51 causes chromosomal rearrangements and stimulates tumorigenesis. RAD51C has been identified as a potential tumor suppressor and a breast and ovarian cancer susceptibility gene. Recent studies have also implicated estrogen as a DNA-damaging agent that causes DSBs. We found that in ERα-positive breast cancer cells, estrogen transcriptionally regulates RAD51C expression in ERα-dependent mechanism. Moreover, estrogen induces RAD51C assembly into nuclear foci at DSBs, which is a precursor to RAD51 complex recruitment to the nucleus. Additionally, disruption of ERα signaling by either anti-estrogens or siRNA prevented estrogen induced upregulation of RAD51C. We have also found an association of a worse clinical outcome between RAD51C expression and ERα status of tumors. These findings provide insight into the mechanism of genomic instability in ERα-positive breast cancer and suggest that individuals with mutations in RAD51C that are exposed to estrogen would be more susceptible to accumulation of DNA damage, leading to cancer progression.
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Affiliation(s)
- Anya Alayev
- a Department of Biology , Yeshiva University , New York , NY , USA
| | - Rachel S Salamon
- a Department of Biology , Yeshiva University , New York , NY , USA
| | - Subrata Manna
- a Department of Biology , Yeshiva University , New York , NY , USA
| | - Naomi S Schwartz
- a Department of Biology , Yeshiva University , New York , NY , USA
| | - Adi Y Berman
- a Department of Biology , Yeshiva University , New York , NY , USA
| | - Marina K Holz
- a Department of Biology , Yeshiva University , New York , NY , USA.,b Department of Molecular Pharmacology and the Albert Einstein Cancer Center , Albert Einstein College of Medicine , Bronx , NY , USA
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10
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Yard BD, Reilly NM, Bedenbaugh MK, Pittman DL. RNF138 interacts with RAD51D and is required for DNA interstrand crosslink repair and maintaining chromosome integrity. DNA Repair (Amst) 2016; 42:82-93. [PMID: 27161866 PMCID: PMC4884500 DOI: 10.1016/j.dnarep.2016.04.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/08/2016] [Accepted: 04/15/2016] [Indexed: 11/26/2022]
Abstract
The RAD51 family is integral for homologous recombination (HR) mediated DNA repair and maintaining chromosome integrity. RAD51D, the fourth member of the family, is a known ovarian cancer susceptibility gene and required for the repair of interstrand crosslink DNA damage and preserving chromosomal stability. In this report, we describe the RNF138 E3 ubiquitin ligase that interacts with and ubiquitinates the RAD51D HR protein. RNF138 is a member of an E3 ligase family that contains an amino-terminal RING finger domain and a putative carboxyl-terminal ubiquitin interaction motif. In mammalian cells, depletion of RNF138 increased the stability of the RAD51D protein, suggesting that RNF138 governs ubiquitin-proteasome-mediated degradation of RAD51D. However, RNF138 depletion conferred sensitivity to DNA damaging agents, reduced RAD51 focus formation, and increased chromosomal instability. Site-specific mutagenesis of the RNF138 RING finger domain demonstrated that it was necessary for RAD51D ubiquitination. Presence of RNF138 also enhanced the interaction between RAD51D and a known interacting RAD51 family member XRCC2 in a yeast three-hybrid assay. Therefore, RNF138 is a newly identified regulatory component of the HR mediated DNA repair pathway that has implications toward understanding how ubiquitination modifies the functions of the RAD51 paralog protein complex.
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Affiliation(s)
- Brian D Yard
- Department of Translational Hematology and Oncology Research, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH 44195, USA
| | - Nicole M Reilly
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Michael K Bedenbaugh
- Department of Pharmacy Services, Greenville Health System, Greenville, SC 29615, USA
| | - Douglas L Pittman
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA.
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11
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Han D, Liang J, Lu Y, Xu L, Miao S, Lu LY, Song W, Wang L. Ubiquitylation of Rad51d Mediated by E3 Ligase Rnf138 Promotes the Homologous Recombination Repair Pathway. PLoS One 2016; 11:e0155476. [PMID: 27195665 PMCID: PMC4873259 DOI: 10.1371/journal.pone.0155476] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 04/29/2016] [Indexed: 11/18/2022] Open
Abstract
Ubiquitylation has an important role as a signal transducer that regulates protein function, subcellular localization, or stability during the DNA damage response. In this study, we show that Ring domain E3 ubiquitin ligases RNF138 is recruited to DNA damage site quickly. And the recruitment is mediated through its Zinc finger domains. We further confirm that RNF138 is phosphorylated by ATM at Ser124. However, the phosphorylation was dispensable for recruitment to the DNA damage site. Our findings also indicate that RAD51 assembly at DSB sites following irradiation is dramatically affected in RNF138-deficient cells. Hence, RNF138 is likely involved in regulating homologous recombination repair pathway. Consistently, efficiency of homologous recombination decreased observably in RNF138-depleted cells. In addition, RNF138-deficient cell is hypersensitive to DNA damage insults, such as IR and MMS. And the comet assay confirmed that RNF138 directly participated in DNA damage repair. Moreover, we find that RAD51D directly interacted with RNF138. And the recruitment of RAD51D to DNA damage site is delayed and unstable in RNF138-depleted cells. Taken together, these results suggest that RNF138 promotes the homologous recombination repair pathway.
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Affiliation(s)
- Deqiang Han
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
- Department of Cancer Genetics and Epigenetics; Beckman Research Institute; City of Hope, Duarte, California, United States of America
| | - Junbo Liang
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Yalan Lu
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Longchang Xu
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Shiying Miao
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Lin-Yu Lu
- Key Laboratory of Reproductive Genetics, Ministry of Education and Women's Reproductive Health Laboratory of Zhejiang Province, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Wei Song
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
- * E-mail: (WS); (LW)
| | - Linfang Wang
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
- * E-mail: (WS); (LW)
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12
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Taylor MRG, Špírek M, Chaurasiya KR, Ward JD, Carzaniga R, Yu X, Egelman EH, Collinson LM, Rueda D, Krejci L, Boulton SJ. Rad51 Paralogs Remodel Pre-synaptic Rad51 Filaments to Stimulate Homologous Recombination. Cell 2015; 162:271-286. [PMID: 26186187 PMCID: PMC4518479 DOI: 10.1016/j.cell.2015.06.015] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/27/2015] [Accepted: 06/01/2015] [Indexed: 10/31/2022]
Abstract
Repair of DNA double strand breaks by homologous recombination (HR) is initiated by Rad51 filament nucleation on single-stranded DNA (ssDNA), which catalyzes strand exchange with homologous duplex DNA. BRCA2 and the Rad51 paralogs are tumor suppressors and critical mediators of Rad51. To gain insight into Rad51 paralog function, we investigated a heterodimeric Rad51 paralog complex, RFS-1/RIP-1, and uncovered the molecular basis by which Rad51 paralogs promote HR. Unlike BRCA2, which nucleates RAD-51-ssDNA filaments, RFS-1/RIP-1 binds and remodels pre-synaptic filaments to a stabilized, "open," and flexible conformation, in which the ssDNA is more accessible to nuclease digestion and RAD-51 dissociation rate is reduced. Walker box mutations in RFS-1, which abolish filament remodeling, fail to stimulate RAD-51 strand exchange activity, demonstrating that remodeling is essential for RFS-1/RIP-1 function. We propose that Rad51 paralogs stimulate HR by remodeling the Rad51 filament, priming it for strand exchange with the template duplex.
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Affiliation(s)
- Martin R G Taylor
- DNA Damage Response Laboratory, Clare Hall Laboratory, The Francis Crick Institute, South Mimms EN6 3LD, UK
| | - Mário Špírek
- Department of Biology, Masaryk University, 62500 Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital in Brno, 62500 Brno, Czech Republic
| | - Kathy R Chaurasiya
- Section of Virology, Single Molecule Imaging Group and MRC Clinical Sciences Centre, Department of Medicine, Imperial College London, London W12 0NN, UK
| | - Jordan D Ward
- DNA Damage Response Laboratory, Clare Hall Laboratory, The Francis Crick Institute, South Mimms EN6 3LD, UK; UCSF-Mission Bay, Genentech Hall S574, San Francisco, CA 94158, USA
| | - Raffaella Carzaniga
- Electron Microscopy Science Technology Platform, Lincoln's Inn Fields Laboratory, The Francis Crick Institute, London WC2A 3LY, UK
| | - Xiong Yu
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Lucy M Collinson
- Electron Microscopy Science Technology Platform, Lincoln's Inn Fields Laboratory, The Francis Crick Institute, London WC2A 3LY, UK
| | - David Rueda
- Section of Virology, Single Molecule Imaging Group and MRC Clinical Sciences Centre, Department of Medicine, Imperial College London, London W12 0NN, UK
| | - Lumir Krejci
- Department of Biology, Masaryk University, 62500 Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital in Brno, 62500 Brno, Czech Republic; National Centre for Biomolecular Research, Masaryk University, 62500 Brno, Czech Republic.
| | - Simon J Boulton
- DNA Damage Response Laboratory, Clare Hall Laboratory, The Francis Crick Institute, South Mimms EN6 3LD, UK.
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13
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Prakash R, Zhang Y, Feng W, Jasin M. Homologous recombination and human health: the roles of BRCA1, BRCA2, and associated proteins. Cold Spring Harb Perspect Biol 2015; 7:a016600. [PMID: 25833843 DOI: 10.1101/cshperspect.a016600] [Citation(s) in RCA: 561] [Impact Index Per Article: 62.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Homologous recombination (HR) is a major pathway for the repair of DNA double-strand breaks in mammalian cells, the defining step of which is homologous strand exchange directed by the RAD51 protein. The physiological importance of HR is underscored by the observation of genomic instability in HR-deficient cells and, importantly, the association of cancer predisposition and developmental defects with mutations in HR genes. The tumor suppressors BRCA1 and BRCA2, key players at different stages of HR, are frequently mutated in familial breast and ovarian cancers. Other HR proteins, including PALB2 and RAD51 paralogs, have also been identified as tumor suppressors. This review summarizes recent findings on BRCA1, BRCA2, and associated proteins involved in human disease with an emphasis on their molecular roles and interactions.
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Affiliation(s)
- Rohit Prakash
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065
| | - Yu Zhang
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065
| | - Weiran Feng
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065 Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, New York 10065
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065 Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, New York 10065
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14
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DNA repair pathways in trypanosomatids: from DNA repair to drug resistance. Microbiol Mol Biol Rev 2014; 78:40-73. [PMID: 24600040 DOI: 10.1128/mmbr.00045-13] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
All living organisms are continuously faced with endogenous or exogenous stress conditions affecting genome stability. DNA repair pathways act as a defense mechanism, which is essential to maintain DNA integrity. There is much to learn about the regulation and functions of these mechanisms, not only in human cells but also equally in divergent organisms. In trypanosomatids, DNA repair pathways protect the genome against mutations but also act as an adaptive mechanism to promote drug resistance. In this review, we scrutinize the molecular mechanisms and DNA repair pathways which are conserved in trypanosomatids. The recent advances made by the genome consortiums reveal the complete genomic sequences of several pathogens. Therefore, using bioinformatics and genomic sequences, we analyze the conservation of DNA repair proteins and their key protein motifs in trypanosomatids. We thus present a comprehensive view of DNA repair processes in trypanosomatids at the crossroads of DNA repair and drug resistance.
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15
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Fayaz S, Fard-Esfahani P, Fard-Esfahani A, Mostafavi E, Meshkani R, Mirmiranpour H, Khaghani S. Assessment of genetic mutations in the XRCC2 coding region by high resolution melting curve analysis and the risk of differentiated thyroid carcinoma in Iran. Genet Mol Biol 2012; 35:32-7. [PMID: 22481871 PMCID: PMC3313513 DOI: 10.1590/s1415-47572012005000011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2011] [Accepted: 10/05/2011] [Indexed: 11/22/2022] Open
Abstract
Homologous recombination (HR) is the major pathway for repairing double strand breaks (DSBs) in eukaryotes and XRCC2 is an essential component of the HR repair machinery. To evaluate the potential role of mutations in gene repair by HR in individuals susceptible to differentiated thyroid carcinoma (DTC) we used high resolution melting (HRM) analysis, a recently introduced method for detecting mutations, to examine the entire XRCC2 coding region in an Iranian population. HRM analysis was used to screen for mutations in three XRCC2 coding regions in 50 patients and 50 controls. There was no variation in the HRM curves obtained from the analysis of exons 1 and 2 in the case and control groups. In exon 3, an Arg188His polymorphism (rs3218536) was detected as a new melting curve group (OR: 1.46; 95%CI: 0.432–4.969; p = 0.38) compared with the normal melting curve. We also found a new Ser150Arg polymorphism in exon 3 of the control group. These findings suggest that genetic variations in the XRCC2 coding region have no potential effects on susceptibility to DTC. However, further studies with larger populations are required to confirm this conclusion.
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Affiliation(s)
- Shima Fayaz
- Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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16
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Suwaki N, Klare K, Tarsounas M. RAD51 paralogs: roles in DNA damage signalling, recombinational repair and tumorigenesis. Semin Cell Dev Biol 2011; 22:898-905. [PMID: 21821141 DOI: 10.1016/j.semcdb.2011.07.019] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 07/19/2011] [Accepted: 07/21/2011] [Indexed: 11/18/2022]
Abstract
Chromosomal double-strand breaks (DSBs) have the potential to permanently arrest cell cycle progression and endanger cell survival. They must therefore be efficiently repaired to preserve genome integrity and functionality. Homologous recombination (HR) provides an important error-free mechanism for DSB repair in mammalian cells. In addition to RAD51, the central recombinase activity in mammalian cells, a family of proteins known as the RAD51 paralogs and consisting of five proteins (RAD51B, RAD51C, RAD51D, XRCC2 and XRCC3), play an essential role in the DNA repair reactions through HR. The RAD51 paralogs act to transduce the DNA damage signal to effector kinases and to promote break repair. However, their precise cellular functions are not fully elucidated. Here we discuss recent advances in our understanding of how these factors mediate checkpoint responses and act in the HR repair process. In addition, we highlight potential functional similarities with the BRCA2 tumour suppressor, through the recently reported links between RAD51 paralog deficiencies and tumorigenesis triggered by genome instability.
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Affiliation(s)
- Natsuko Suwaki
- The Cancer Research UK/Medical Research Council Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford, UK
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17
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The importance of XRCC2 in RAD51-related DNA damage repair. DNA Repair (Amst) 2010; 9:517-25. [DOI: 10.1016/j.dnarep.2010.01.016] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 12/04/2009] [Accepted: 01/28/2010] [Indexed: 12/11/2022]
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18
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Rajesh C, Gruver AM, Basrur V, Pittman DL. The interaction profile of homologous recombination repair proteins RAD51C, RAD51D and XRCC2 as determined by proteomic analysis. Proteomics 2009; 9:4071-86. [PMID: 19658102 DOI: 10.1002/pmic.200800977] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The RAD51 family of proteins is involved in homologous recombination (HR) DNA repair and maintaining chromosome integrity. To identify candidates that interact with HR proteins, the mouse RAD51C, RAD51D and XRCC2 proteins were purified using bacterial expression systems and each of them used to co-precipitate interacting partners from mouse embryonic fibroblast cellular extracts. Mass spectroscopic analysis was performed on protein bands obtained after 1-D SDS-PAGE of co-precipitation eluates from cell extracts of mitomycin C treated and untreated mouse embryonic fibroblasts. Profiling of the interacting proteins showed a clear bias toward nucleic acid binding and modification proteins. Interactions of four candidate proteins (SFPQ, NONO, MSH2 and mini chromosome maintenance protein 2) were confirmed by Western blot analysis of co-precipitation eluates and were also verified to form ex vivo complexes with RAD51D. Additional interacting proteins were associated with cell division, embryo development, protein and carbohydrate metabolism, cellular trafficking, protein synthesis, modification or folding, and cell structure or motility functions. Results from this study are an important step toward identifying interacting partners of the RAD51 paralogs and understanding the functional diversity of proteins that assist or regulate HR repair mechanisms.
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Affiliation(s)
- Changanamkandath Rajesh
- Department of Pharmaceutical and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
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19
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Nadkarni A, Rajesh P, Ruch RJ, Pittman DL. Cisplatin resistance conferred by the RAD51D (E233G) genetic variant is dependent upon p53 status in human breast carcinoma cell lines. Mol Carcinog 2009; 48:586-91. [PMID: 19347880 DOI: 10.1002/mc.20545] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
RAD51D, a paralog of the mammalian RAD51 gene, contributes towards maintaining genomic integrity by homologous recombination DNA repair and telomere maintenance. A RAD51D variant, E233G, was initially identified as a potential susceptibility allele in high-risk, site-specific, familial breast cancer. We describe in this report that the Rad51d (E233G) genetic variant confers increased cisplatin resistance and cell growth phenotypes in human breast carcinoma cell lines with a mutant p53 gene (BT20 and T47D) but not with a wild-type p53 gene (MCF-7). Treatment with a p53 specific inhibitor, pifithrin alpha, restored this resistant phenotype in the MCF-7 cell line. Additionally, Rad51d (E233G) conferred increased cisplatin resistance of an MCF7 cell line in which p53 expression was stably knocked down by shRNAp53, indicating that the effect of this variant is dependent upon p53 status. Further study of Rad51d (E233G) will provide mechanistic insight towards the role of RAD51D in cellular response to anticancer agents and as a potential target for cancer therapy.
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Affiliation(s)
- Aditi Nadkarni
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine, Toledo, Ohio, USA
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20
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Gruver AM, Yard BD, McInnes C, Rajesh C, Pittman DL. Functional characterization and identification of mouse Rad51d splice variants. BMC Mol Biol 2009; 10:27. [PMID: 19327148 PMCID: PMC2667185 DOI: 10.1186/1471-2199-10-27] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Accepted: 03/27/2009] [Indexed: 11/10/2022] Open
Abstract
Background The homologous recombination (HR) pathway is vital for maintaining genomic integrity through the restoration of double-stranded breaks and interstrand crosslinks. The RAD51 paralogs (RAD51B, RAD51C, RAD51D, XRCC2, XRCC3) are essential for this process in vertebrates, and the RAD51D paralog is unique in that it participates in both HR repair and telomere maintenance. RAD51D is also known to directly interact with the RAD51C and XRCC2 proteins. Rad51d splice variants have been reported in mouse and human tissues, supportive of a role for alternative splicing in HR regulation. The present study evaluated the interaction of the Rad51d splice isoform products with RAD51C and XRCC2 and their expression patterns. Results Yeast-2-hybrid analysis was used to determine that the Mus musculus Rad51d splice variant product RAD51DΔ7b (deleted for residues 219 through 223) was capable of interacting with both RAD51C and XRCC2 and that RAD51D+int3 interacted with XRCC2. In addition, the linker region (residues 54 through 77) of RAD51D was identified as a region that potentially mediates binding with XRCC2. Cellular localization, detected by EGFP fusion proteins, demonstrated that each of the splice variant products tested was distributed throughout the cell similar to the full-length protein. However, none of the splice variants were capable of restoring resistance of Rad51d-deficient cell lines to mitomycin C. RT-PCR expression analysis revealed that Rad51dΔ3 (deleted for exon 3) and Rad51dΔ5 (deleted for exon 5)transcripts display tissue specific expression patterns with Rad51dΔ3 being detected in each tissue except ovary and Rad51dΔ5 not detected in mammary gland and testis. These expression studies also led to the identification of two additional Rad51d ubiquitously expressed transcripts, one deleted for both exon 9 and 10 and one deleted for only exon 10. Conclusion These results suggest Rad51d alternative splice variants potentially modulate mechanisms of HR by sequestering either RAD51C or XRCC2.
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Affiliation(s)
- Aaron M Gruver
- Department of Pharmaceutical and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina Campus, Columbia, SC 29208, USA.
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22
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Wiese C, Hinz JM, Tebbs RS, Nham PB, Urbin SS, Collins DW, Thompson LH, Schild D. Disparate requirements for the Walker A and B ATPase motifs of human RAD51D in homologous recombination. Nucleic Acids Res 2006; 34:2833-43. [PMID: 16717288 PMCID: PMC1464408 DOI: 10.1093/nar/gkl366] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In vertebrates, homologous recombinational repair (HRR) requires RAD51 and five RAD51 paralogs (XRCC2, XRCC3, RAD51B, RAD51C and RAD51D) that all contain conserved Walker A and B ATPase motifs. In human RAD51D we examined the requirement for these motifs in interactions with XRCC2 and RAD51C, and for survival of cells in response to DNA interstrand crosslinks (ICLs). Ectopic expression of wild-type human RAD51D or mutants having a non-functional A or B motif was used to test for complementation of a rad51d knockout hamster CHO cell line. Although A-motif mutants complement very efficiently, B-motif mutants do not. Consistent with these results, experiments using the yeast two- and three-hybrid systems show that the interactions between RAD51D and its XRCC2 and RAD51C partners also require a functional RAD51D B motif, but not motif A. Similarly, hamster Xrcc2 is unable to bind to the non-complementing human RAD51D B-motif mutants in co-immunoprecipitation assays. We conclude that a functional Walker B motif, but not A motif, is necessary for RAD51D's interactions with other paralogs and for efficient HRR. We present a model in which ATPase sites are formed in a bipartite manner between RAD51D and other RAD51 paralogs.
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Affiliation(s)
- Claudia Wiese
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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23
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Martín V, Chahwan C, Gao H, Blais V, Wohlschlegel J, Yates JR, McGowan CH, Russell P. Sws1 is a conserved regulator of homologous recombination in eukaryotic cells. EMBO J 2006; 25:2564-74. [PMID: 16710300 PMCID: PMC1478202 DOI: 10.1038/sj.emboj.7601141] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Accepted: 04/20/2006] [Indexed: 12/21/2022] Open
Abstract
Rad52-dependent homologous recombination (HR) is regulated by the antirecombinase activities of Srs2 and Rqh1/Sgs1 DNA helicases in fission yeast and budding yeast. Functional analysis of Srs2 in Schizosaccharomyces pombe led us to the discovery of Sws1, a novel HR protein with a SWIM-type Zn finger. Inactivation of Sws1 suppresses the genotoxic sensitivity of srs2Delta and rqh1Delta mutants and rescues the inviability of srs2Delta rqh1Delta cells. Sws1 functions at an early step of recombination in a pro-recombinogenic complex with Rlp1 and Rdl1, two RecA-like proteins that are most closely related to the human Rad51 paralogs XRCC2 and RAD51D, respectively. This finding indicates that the XRCC2-RAD51D complex is conserved in lower eukaryotes. A SWS1 homolog exists in human cells. It associates with RAD51D and ablating its expression reduces the number of RAD51 foci. These studies unveil a conserved pathway for the initiation and control of HR in eukaryotic cells.
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Affiliation(s)
- Victoria Martín
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Charly Chahwan
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Hui Gao
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Véronique Blais
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - James Wohlschlegel
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - John R Yates
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Clare H McGowan
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Paul Russell
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA, USA
- Department of Molecular Biology, MB3, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA. Tel.: +1 858 784 8273; Fax: +1 858 784 2265; E-mail:
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