| Project/Area Number |
10680584
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural biochemistry
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| Research Institution | Kumamoto University |
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Principal Investigator |
IZUTA Shunji Kumamoto University, Graduate School of Science and Technology, Associate Professor, 大学院・自然科学研究科, 助教授 (50203047)
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| Co-Investigator(Kenkyū-buntansha) |
伊豆田 俊二 熊本大学, 大学院・自然科学研究科, 助教授 (50203047)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 1999: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1998: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | Eukaryote / Cell cycle / DNA replication / Mutagenic nucleotide / Checkpoint control / Cell free system / African claw frog / UV-damage / 変異原生ヌクレオチド |
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| Research Abstract |
To elucidate the response to oxidative stress in eukaryotic cells, the effect of an oxidized nucleotide, 8-oxo-2'-deoxyguanosine 5'-triphosphate (8-oxo-dGTP) generated from dGTP with an active oxygen, on the S-phase progression was studied using DNA replication system in Xenopus egg lysate with a single-stranded DNA (ssDNA) template as a model of DNA synthesis at the S-phase. Amounts of newly synthesized DNA were reduced according to the increasing concentration of 8-oxo-dGTP. Pulse labeling-analysis revealed that the 8-oxo-dGTP could delay the rate of long chain synthesis by DNA polymeraseδ rather than the initiation by DNA polymerase α-primase. This delay was recovered by the addition of a protein kinase inhibitor, staurosporine. These results indicate that the staurosporine-sensitive protein kinase, such. As protein kinase C family, may contribute for the delay of DNA synthesis by 8-oxo-dGTP. Ultraviolet (UV)-irradiated ssDNA also caused the delay of DNA synthesis on undamaged templates, however, this delay was not recovered by staurosporine. Therefore, the mechanism for delay of DNA synthesis by 8-oxo-dGTP may be different from that by UV-lesions.
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