| Project/Area Number |
04808026
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
物質生物化学
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| Research Institution | Kitasato University School of Hygienic Sciences |
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Principal Investigator |
OHTSUKI Kenzo Associate Prof., Kitasato University, 衛生学部, 助教授 (60124559)
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| Co-Investigator(Kenkyū-buntansha) |
SAITO Hitoshi Research Fellow, Kitasato University, 衛生学部, 学術振興会研究員 (60221991)
OHISHI Masamichi Assistant Prof., Kitasato University, 衛生学部, 助手 (40233027)
SUGII Syunji Lecture, Kitasato University, 衛生学部, 講師 (70162865)
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| Project Period (FY) |
1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1992: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | Casein Kinase II / 98 kDa DNA-binding protein / Specific phosphorylation / Effective substrate for CK-II / Transcriptional regulation / Signal transduction / Fertilization / Heat schock proteiu / signal伝達機構 |
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| Research Abstract |
The present study had been carried out to characterize biochemically casein kinase II(CK-II) and its specific phosphate acceptors (p98) in sea urchin eggs, and to identify specific signal factor, which is responsible for the specific activation of CK-II during fertilization.
(1)Characterization of CK-II and p98 from unfertilized sea urchin eggs
The kinase was highly purified from a 1.5 M KCl extract of unfertilized sea urchin eggs by means of DEAE-cellulose column chromatography, Sephacryl S300 gel filtration and HPLC column chromatography, successively. The biochemical properties, such as requirements of divalent cations, phosphate acceptors and phosphate donors, response to basic polypeptides (histone and protamine) and heparin, and subunit structure of the purified CK-II were similar to those of the kinases from various animal cells. The 98 kDa polypeptide(designated as p98)had been purified to homogeneity from the 1.5 M KCI egg extract by means of HPLC column chromatographies as an e
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ffective phosphate acceptor for CK-II. It was found that (i) p98 (apparent pI 10.0)had DNA-binding ability and functioned as an effective phosphate acceptor for CK-II in vitro ; and(ii)phosphorylation of p98 by the kinase was greatly stimulated by either protamine or poly-Arg.
(2)Biological significance of p98 phosphorylation by CK-II during fertilization
To determine the biological significance of specific phosphorylation of p98(DNA-binding protein)by CK-II during fertilization, the DEAE-cellulose fractions were prepared from different stages of the eggs after fertilization. It was found that(i)slective phosphorylation of p98 by CK-II was detected during fertilization ; (ii) protamine (sperm basic protein) functions as a potent activator for CK-II ; and (iii) the phosphorylated form of p98 stimulated the activity of RNA polymerase II in vitro. These observations suggest that specific phosphorylation of p98 by the activated CK-II may play an important role in the transcriptional regulation in the eggs accompanying fertilization. Less
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