| Project/Area Number |
08458222
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | TEIKYO UNIVERSITY |
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Principal Investigator |
AIZAWA Shin-ichi TEIKYO UNIVERSITY,BIOSCIENCES,ASSOCIATE PROFESSOR, 理工学部, 助教授 (50222451)
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| Co-Investigator(Kenkyū-buntansha) |
KATAYAMA Eisaku THE UNIVERSITY OF TOKYO,INSTITUTE OF MEDICAL SCIENCE,ASSOCIATE PROFESSOR, 医科学研究所, 助教授 (50111505)
久堀 智子 帝京大学, 理工学部, 特別研究員
丹下 友子 (株)サイエンスサービス, 研究部, 研究員 (00276734)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥8,300,000 (Direct Cost: ¥8,300,000)
Fiscal Year 1997: ¥4,300,000 (Direct Cost: ¥4,300,000)
Fiscal Year 1996: ¥4,000,000 (Direct Cost: ¥4,000,000)
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| Keywords | BACTERIA / FLAGELLA / EXPORT APPARATUS / PATHOGENICITY / TYPE III EXPORT SYSTEMS / タンパク質輸送 / 急速凍結法 / 浸透圧ショック法 / 電子顕微鏡 / 分泌タンパク質 / イムノブロット法 |
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| Research Abstract |
Bacterial flagellum is an extracellular organelle. Therefore, most of the component proteins once synthesized in the cytoplasm have to be exported outside the cell through an export apparatus specific for flagellar proteins.
Among the component proteins in the apparatus, FliH and FliI proteins are regarded to work as a gate keeper, because the deletion mutants of those genes result in blockage of flagellation at the early steps.
We have developed a method to visualize flagellar basal structures from inside the cell. The method includes revised techniques for preparing osmotically-shocked cells, and the quick-freeze deep-ethch electron microscopy. We have succeeded in visualization of the flagellar C ring structure of Salmonella typhimurium.
Furthermore, in the course of developing the methods, we found a supramolecular structure resembling to flagellar basal body. Since it has a straight needle instead of the curved hook, we call the structure the needle complex. The needle complexes were purified, separated into components by SDS-PAGE, blotted onto nitrocellulose papers, and analyzed by the amino acid sequencer. The major component proteins were identified as PrgH, PrgK, and InvG that are known as pathogenic factors. These results strongly support a hypothesis that flagella and pathogenicity have the same origin.
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