| Project/Area Number |
61480022
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
動物発生・生理学
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| Research Institution | Osaka University |
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Principal Investigator |
OZAKI Koichi (1988) Department of Biology, Faculty of Science, Osaka University Research Assistant, 理学部, 助手 (90194539)
原 富之 (1986-1987) 大阪大学, 理学部, 教授 (70028265)
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| Co-Investigator(Kenkyū-buntansha) |
HARA Reiko Department of Biology, Faculty of Science, Osaka University Research Assistant, 理学部, 講師 (20075138)
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| Project Period (FY) |
1986 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥4,500,000 (Direct Cost: ¥4,500,000)
Fiscal Year 1988: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1986: ¥3,200,000 (Direct Cost: ¥3,200,000)
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| Keywords | Retinal / Retinol / Rhodopsin / Retinochrome / Retinal-binding Protein / Vision / Retina / 視細胞 |
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| Research Abstract |
Many studies of molecular bases in vision have been developed in the photochemistry of visual pigments and the light energy transduction including amplification of photosignals. In addition to these problems, it is also fascinating to understand the background which makes possible the continuation of photoreceptive capacity of visual cell. Such a problem virtually includes the regeneration of photopigments and the flow of retinal isomers within the cell. With regard to this, we recently isolated a retinal-binding protein (RALBP), and found a new type of the regeneration characterized by the mutual exchange of chromophores between RALBP and meta-pigment. This suggested a possibility that, in the visual cells, metarhodopsin and metaretinochrome may eventually interchange their own chromophores through the mediation of RALBP to regenerate rhodopsin and retinochrome.
In earlier experiments with opsin and metaretinochrome membranes, we demonstrated that the close contact of both the membrane
… More
s resulted in the formation of rhodopsin, the 11-cis-retinal transferred into the opsin membranes. Such membranes derived from the rhabdomal microvilli and the myeloid bodies are originally situated so far away from each other within the cell that some suitable shuttle for retinal was expected to serve between those structures. In fact, the distribution of RALBP described above is restricted to within the visual cells, as suggested by biochemical and immunocytochemical examinations. We now think that most likely, the exchange reaction of retinal between RALBP and metaretinochrome proceeds on the myeloid bodies which locate in the basal regins of the outer segments as well as in the inner segments, while that between RALBP and metarhodopsin proceeds on the rhabdomeres in the outer segments. The details of the movement of RALBP in the visual cells were also examined by using isolated exycups. As the result, those two exchange reactions is joined into one by a round trip of RALBP to form the recycling system of retinal. We shall call it the rhodopsin-retinochrome system Less
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