2002 Fiscal Year Final Research Report Summary
Comparison of the mechanism on functional expression of diverged rhodopsins by using their mutants
| Project/Area Number |
13640678
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
TERAKITA Akihisa Graduate School of Science, Associate Professor, 大学院・理学研究科, 助教授 (30212062)
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| Project Period (FY) |
2001 – 2002
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| Keywords | rhodopsin / opsin family / diversity / retinal schiff-base / counterion / G protein / photoisomerase |
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| Research Abstract |
The members of rhodopsin family are divided into at least five subgroups. In this study, the amphioxus Go-coupled rhodopsin and peropsin were investigated to understand the mechanism on the functional expression of diverged rhodopsins ; specifically, 1. comparison of the amino acid residue which functions as counterion 2.comparison of G protein activation mechanism between Go-coupled rhodopsin and vertebrate rhodopsins, and then 3. investigation of physiological function of peropsin.
Results :
1. Unlike bovine rhodopsin but like retinochrome, amphioxus relatives belonging to the groups of Go-coupled rhodopsins and peropsins have the glutamic acid counterions at position 181 in the 2nd extracellular loop.
2. We established the procedures to measure the G protein activation ability of the amphioxus rhodopsin to strictly compare the G protein activation mechanism with vertebrate rhodopsins.
3. HPLC analyses of chromophore retinal revealed that peropsin has all-trans-retinal as the chromophore, and light causes the isomerization from all-trans to 11-cis. This finding suggested that peropsin functions as photoisomerase like retinochrome and RGR.
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