2003 Fiscal Year Final Research Report Summary
Analysis of structure and function of quinone photosensor and photosignaling in unicellular organisms
| Project/Area Number |
13640684
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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 Kochi University, Faculty of Science, Professor, 理学部, 教授 (90209510)
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| Project Period (FY) |
2001 – 2003
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| Keywords | signal transduction / unicellular organism / blepharismin / photosensor / quinone / proton signal |
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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 this project, we obtained following results.
1.Structure of photosensory complex : Spectroscopic analysis of free pigment(blepharismin) and pigment(blepharismin)/200kD protein complex, analysis of pigment interaction with other proteins obtained from other organism. The quenching of the pigment observed only in the blepharismin/200kD protein complex, suggesting that blepharismin is bound to 200kD protein to form a functional complex.
2.Photosignaling between photoreceptor organelle and cell membrane : Photostimulation of the cells elicited that a decrease in H+ concentration of intermembrane space of the pigment vesicles(pigment granules). The result indicate that H^+ are translocated to cytoplasm in the vicinity of plasma membrane. In the presence of protonophore, photoresponse of the cells were prevented at lower pH. The result strongly suggests that photosignal is finally transduced into H^+ translocation to the vicinity of plasma membrane to elicit depolarization of membrane.
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Research Products
(18 results)
