| Project/Area Number |
14540626
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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 | OSAKA UNIVERSITY |
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Principal Investigator |
OZAKI Koichi OSAKA UNIVERSITY, GRADUATE SCHOOL of Frontier Bioscience, Associate Professor, 生命機能研究科, 助教授 (90194539)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2002: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | visual pigment / receptor / vesicle transport / Rab / photoreceptor cell / synaptic vesicle / pigment granule / rhodopsin / ショウジョウバエ / 質量分析 / クルマエビ / 多胞体 / 網膜 / オプシン |
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| Research Abstract |
To investigate the traffic pathway of rhodopsin-carrying vesicles, we carried out fluorescence microscopic examination of the Drosophila retina using anti-opsin antibody. The results K demonstrated that rhodopsin is concentrated into cytoplasmic large vesicles (RLVs, >200 nm in diameter) prior to its appearance in rhabdomeric membrane. TRP, a calcium channel protein on microvillar membrane, is co-localized in RLV, while Na^+-K^+ ATPase is not transported into the vesicles. Electronmicroscopic observation identified RLVs as multivesicular endosomes (MVEs). By reducing Rab11 activity, rhodopsin failed to reach the rhabdomere and instead accumulated in vesicles dispersed throughout the cytoplasm. Organization of rhabdomere was also blocked. These data indicate Rab11 reduction inhibits MVE biogenesis and rhabdomere membrane traffic. For further investigation of rhodopsin transport, we isolated rhodopsin-carrying vesicles using magnetic beads coated with anti-opsin antibody. Immunoblot analysis demonstrated that the isolated vesicles Contained immature rhodopsin. Further biochemical analysis of these vesicles is in process. Considering the much larger tissue size, eyes of crustacean is superior to those of Drosophila for biochemical studies of rhodopsin transport. We recently found that MVEs accumulate in prawn photoreceptor cells under a particular light condition. This suggests that the cells would be suitable for biochemical studies of vesicle transport.
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