| Project/Area Number |
03454552
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
放射線5生物学
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| Research Institution | Kobe University |
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Principal Investigator |
FUJIWARA Yoshisada Kobe University School of Medicine, Department of Radiation Biophysics and Genetics, Professor., 医学部, 教授 (70030848)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUMOTO Akira Kobe University School of Medicine, Department of Radiation Biophysics and Genet, 医学部, 講師 (80181759)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥5,300,000 (Direct Cost: ¥5,300,000)
Fiscal Year 1992: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1991: ¥3,800,000 (Direct Cost: ¥3,800,000)
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| Keywords | xeroderma pigmentosum / DNA excision repair / repair defect / XPD-complementing cDNA transformation / Expression cloning / cDNA / D群相補cDNA / cDNA導入による形質転換 / DNA除去終復 / D群相補遺伝子 |
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| Research Abstract |
Xeroderma pigmentosum (XP) group D (XPD) exhibits a severe defect in excision repair of UV-induced pyrimidine dimers and (6-4) photoproducts in the DNA and a high frequency of sunlight-induced skin cancers. We have so far assigned 13 definite and 6 possible XPD patients in Japan (-10% of all assigned XPs) by the cell fusion-complementation test. We established an SV40 origin-defective T antigen DNA-immortalized cell line, XP59TOpSV, from fibroblasts of Japanese XPD patient XP59TO. XP59TOpSV cells were transfected by large scale repetitions with the three types of normal human fibroblast cDNA libraries constructed in pcD, pcD2 (with the neo gene), and lambdapCEV mammalian expression vector (with unidirectionally inserted cDNA and the neo gene). After the 3 X UV selections for pcD-cDNA transfected cells and the G418 - 2 X UV selections for pcD2-cDNA introduction, the acquired 10 and 21 clones respectively revealed a very slight UV resistance without obvious recovery in the DNA repair, suggesting no full-length complementing cDNA. Then we introduced the unidirectional normal-cDNA constructed in lambdapCEV expression vector into 5 x 10^7 XP59TOpSV cells, and obtained the two final, significantly UV-resistant clones revealing the 3-fold recovery compared with the parental cell line. The genomic DNA of one more resistant clone contained the insertion of -2.5 kb cDNA, which showed the same Not I site in the middle and the same PCR product as in ERCC2, indicating that the present cDNA obtained by the expression cloning method complements the repair defect in XPD. RT-PCR of mRNA from three XPD strains indicated an abnormally low, unapmlifiable level of XPD mRNA in a case. Now we are recloning from the libraries for base sequencing.
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