| Project/Area Number |
10640668
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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 |
動物生理・代謝
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| Research Institution | Kochi University |
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Principal Investigator |
MATSUOKA Tatsuomi Faculty of Science, Kochi University, Professor, 理学部, 教授 (90209510)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Blepharisma / photosignal / signal transduction / photoresponse / quinone / blepharismin / キノン光センサー / 単細胞生物 / 光行動 |
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| Research Abstract |
Quinone photosensor complex responsible for the photobehavior of unicellular organisms is new type of photoreceptor that is different from rhodopsins. In the present study, we obtained following results.
1. Structure of photosensory complex : Spectroscopic analysis of free pigment (blepharismin) and pigment (blepharismin)/protein complex, analysis of pigment contents bound to the protein or observation of photosensory organelle suggested that a large number of free pigment molecules are regularly arranged in vivo. This crystal-like structure may function as light-harvesting antenna for activating reaction center blepharismin/200 kD protein complex.
2. Photosensory transduction : Analyses of molecular structure of light-irradiated blepharismin suggested that light-induced dissociation of phenol group (side chain) is not involved in activation of photosensory transduction chain. Spectroscopic analysis of photoreceptor complex indicated that active oxygen produced by photosensitization of light-activated blepharismin or energy or electron transfer from first excited singlet of pigment would be involved in activation of photosensory transduction chain.
3. Singaling mechanism between photoreceptor organelle and cell membrane : We revealed that photosignal is finally transduced into H^+ signal ; H^+ is released from outer membrane of photoreceptor organelle so that evoked depolarization of cell membrane.
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