2004 Fiscal Year Final Research Report Summary
Functional analysis of genes involved in maintenance of chromosome stability and homologous recombination
| Project/Area Number |
12213059
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| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
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| Allocation Type | Single-year Grants |
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| Review Section |
Biological Sciences
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| Research Institution | Kawasaki Medical School |
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Principal Investigator |
TAKATA Minoru Kawasaki Medical School, Dept of Immunology and Molecular Genetics, Professor, 医学部, 教授 (30281728)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUSHITA Nobuko Kawasaki Med Sch, Dept of Immunol and Mol Genet, Research Associate, 医学部, 助手 (30333222)
KITAO Hiroyuki Kawasaki Med Sch, Deptcf Immunol and Mol Genet, Research Associate, 医学部, 助手 (30368617)
HIRANO Seiki Kawasaki Med Sch, Dept of Immunol and Mol Genet, Research Associate, 医学部, 助手 (20368616)
KIURA Katsuyuki Okayama University Med Sch, 2nd Dept of Med, Assistant Professor, 大学院医歯薬総合研究科, 講師 (10243502)
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| Project Period (FY) |
2000 – 2004
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| Keywords | homologous recombination / DNA repair / DT 40 cells / Rad51 paralogs / Fanconi anemia / sister chromatid exchanges / 姉妹染色分体交換 |
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| Research Abstract |
DNA repair mediated by homologous recombination (HR) is an important mechanism in promoting genome stability and preventing carcinogenesis. In this project, we disrupted putative HR regulators including five Rad51 paralogs and Fanconi anemia genes in chicken cell line DT40.
(1) Cells lacking each of Rad51 paralogs all displayed very similar HR defects such as cisplatin sensitivity, increased chromosomal aberrations, and loss of Rad51 focus formation or gene targeting efficiencies. Since Rad51 paralogs interact with each other, these results suggest that Rad51 paralogs work together as a functional unit in mediating HR reactions through Rad51.
(2) We found that Rad52 (an HR factor) and Xrcc3 (one of Rad51 paralogs) exhibited synthetic lethality in DT40 cells, indicating that there are some overlapping functions between these two molecules.
(3) DT40 mutants lacking FA genes displayed HR defects such as decreased gene targeting efficiencies, a decreased gene conversion frequency at immunoglobulin locus, and impaired HR repair of restriction enzyme-induced chromosonal double strand breaks. These results were the first formal demonstration of the role of FA genes in HR.
(4) We showed epistasis between BLM helicase and the FA pathway in terms of SCE frequency and sensitivities to MMC or cisplatin. BLM helicase seems to be one of the effector molecules of the FA pathway.
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