| Project/Area Number |
11680686
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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 |
Molecular biology
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| Research Institution | RIKEN |
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Principal Investigator |
MATSUMOTO Ken RIKEN. Lab. Cell. Biochem. Senior Staff Scientist, 細胞生化学研究室, 先任研究員 (60222311)
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| Co-Investigator(Kenkyū-buntansha) |
NAGATA Kyosuke Univ.Tsukuba, inst. Bassic Med. Sci, Professor, 基礎医学系, 教授 (40180492)
TSUJIMOTO Masafumi RIKEN, Lab. Cell, Biochem., Chief Scientist, 細胞生化学研究室, 主任研究員 (00281668)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2000: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1999: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | chromatin / histone / histpne chaperon / adenovirus / Xenopus / TAF- I |
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| Research Abstract |
Dynamic remodeling in chromatin structure takes place during early development, represented by sperm chromatin decondensation and pronuclei formation upon fertilization. We found that histone chaperones TAF-I (template activating factor I) and NAP-1 have an activity to mediate decondensation of Xenopus sperm chromatin. TAF-I and NAP-I/TAF-II are highly acidic proteins, which we previously identifiled as host factors required for DNA replication and transcription of adenovirus genome complexed with viral basic proteins. Domain analysis of human TAF-1 revealed that the C-terminal acidic region and the dimerization domain of TAF-lb are both neccssary for the decondensation activity. We detected the b form of TAF-I in Xenopus oocyies and eggs, and the cloning of its cDNA led us to conclude that Xenopus TAF-Ib is capable of mediating. decondensation of the sperm chromatin. TAF-I interacts directiy with sperm-specific basic proteins and removes them from the chromatin. Fufther analysis of the molecular mechanisms revealed that TAF-I remains bound to the decondensed chromatin, of which protein components predominantly consist of core histones H3 and H4.Since TAF-I preferentially binds to histones H3/H4 in solution, we suggest that TAF-I associates with the chromatin through its interaction with histone H3/H4.Continuous search for other host faetors that remodel adenovirus genome idenufied B23 protein as a novel template activating factor. We showed that B23/TAF-III also mediates Xenopus sperm chromatin decondensation, dependent on its acidic regions. These results suggest that histone chaperones such as TAF-I and NAP-I play roles in remodeling higher-order chromatin structure as wen as nucleosomal structure through direct interaction with chromatin basic proteins.
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