| Project/Area Number |
07680782
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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 |
Cell biology
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| Research Institution | Kwansei Gakuin University |
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Principal Investigator |
YAGURA Tatsuo Kwansei Gakuin University, Faculty of Science, Department of Chemistry, Research Professor, 理学部, 教授 (90142108)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1997: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1996: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | Autoimmune disease / Ku / Cell nucleus / ツメガエル / アミノ酸配列 |
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| Research Abstract |
Using specific antibody against autoimmune antigen Ku proteins, we have found that the Ku proteins change yjeir localization in cell nucleus. Next, we have studied the changes in the structure of cell nucleus and cytoplasmic organelles during the inhibition of DNA replication or formation of mitotic chromosomes by cell cycle specific drugs. The study showed the induction of centrosome duplication without cell division to be induced when cells were constrained to be overgrowth. The abnormally duplicated centrosomes localized to the nuclear surface suggesting some unknown structure to bind two organelles existed onto nuclear surface or in nuclear membrane.On the other study, we have obtained novel results using hemin for the nuclear reconstitution process in Xenopus egg extract-cell free nuclear reconstitution system. Hemin severally inhibited the reconstitution of pseudonuclei from sperm head chromatins and DNA replication in these chromatins. The hemin-binding proteins were found to have a role in nuclear membrane reconstitution and purified with aid of heminagarose. On the basis of these studies, we next carried out the study to elucidata the role of Ku proteins on the nuclear structure and function. We have purified two Ku subunit proteins from Xenopus egg extracts and determined their partial peptide sequences. Then, entire nucleotide sequences of both subunit proteins were determined. We have found some highly conserved regions on the amino acid sequences of these proteins. To search possible analogous protein family of Ku proteins, several sites of Ku 80 kDa protein were cloned from the cDNA library, but at present we can not obtain cDNA clones of partially different sequences. Using cDNA clones of Xenopus Ku proteins, we now investigate the role of Ku proteins on the reconstitution of nuclei in Xenopus egg extract system.
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