| Project/Area Number |
02640523
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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 |
植物生理学
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| Research Institution | Okayama University |
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Principal Investigator |
YAMAMOTO Yasusi Okayama Univ. Faculty of Science Associate Professor, 理学部, 助教授 (40091251)
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| Project Period (FY) |
1990 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1992: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | photosynthesis / oxygen evolution / chloroplast / photosystem II / protein / protein transport / photoinhibition / 酵素発生 / 緑化 / 遺伝子発現 / 蛋白質輸送 / クロロフィルタンパク質 / 翻訳後調節 |
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| Research Abstract |
Photosynthetic oxygen-evolving system is organized by the coordinated assembly of the nuclear- and chloroplast-encoded proteins in thylakoid membranes under illumination. In the present study, we investigated synthesis and assembly of the PS-II related proteins in the greening process of Euglena cells and barley seedlings. In Euglena, the antenna chlorophyll-binding proteins CP43/47 are unstable in the early stage of greening, and we found that binding of extrinsic 30 kDa proteins to PS II is responsible for the stabilization of CP43/47. The results suggest that the extrinsic 30 kDa proteins are located closely to the antenna chlorophyll-protein complexes and regulates their conformation.
We also studied transport of the 30 kDa protein in Euglena cells. To see the structure of the precursor to the 30 kDa protein, we carried out cDNA cloning of the protein. The precursor had a presequence different from that of the corresponding protein from higher plants. Contact sites of the envelope of chloroplasts, which are responsible for translocation of the precursor proteins across the envelopes, were examined by electron microscopy. It is probable that transport of nuclear-encoded proteins in chloroplasts is limited by the envelopes consisting of triple membranes.
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