1998 Fiscal Year Final Research Report Summary
Diversities of proteins which participate in photoreception of vertebrate visual cells.
| Project/Area Number |
09440277
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 |
TOKUNAGA Fumio Osaka Univ., Graduate School of Science, Professor, 大学院・理学研究科, 教授 (80025452)
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| Co-Investigator(Kenkyū-buntansha) |
IMAMOTO Yasushi Osaka Univ., Graduate School of Science, Research Associate, 大学院・理学研究科, 助手 (80263200)
HISATOMI Osamu Osaka Univ., Graduate School of Science, Associate Professo, 大学院・理学研究科, 助教授 (60231544)
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| Project Period (FY) |
1997 – 1998
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| Keywords | vision / vertebrates / intracellular transduction / visual pigments / G-proteins / color vision / rods / cones |
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| Research Abstract |
Diversities of proteins participating in transduction in vertebrate visual cells were analyzed by recombinant DNA techniques, histochemical techniques and analyzing techniques for the structures and functions of proteins. (1) cDNAs encoding rhodopsin and red-, blue- and violet-sensitive pigments were cloned and the phylogenetic relationship among the pigments was analyzed. (2) The charged amino acid residues at the C-terminal regions of S-modulin and its homologue, s26 were substituted with each other. The results show that the positive charges increased the affinity to the membrane and the inhibition activity of phosphorylation of visual pigments by rhodopsin kinase. (3) The phylogenetic analysis of arrestins suggests that arrestins working in the photoreceptor cells branched from the arrestins for the receptors of neuron-transmitters before the cone and rod were branched. (4) Two kinds of cDNAs encoding visual pigment kinases were cloned from medaka retina. One was expressed in cone cells and another in rod cells. The amino acid sequences show that the kinase expressed in cone cells have geranylgeranylation signal and that expressed in rod cells farnesylation signal. (5) Three kinds of cDNAs encoding guanylate cyclases were cloned from medaka retina. Two of them was expressed in rod cells and the other in cone cells. (6) Two kinds of cDNAs encoding guanylate cyclase activating protein were cloned from medaka retina. One was expressed in cone cells and another in rod cells. (7) Two kinds of cDNAs encoding phosducin which binds to transducin and controls its life time were cloned from medaka retina. One was expressed in cone cells and another in rod cells. The above results suggest indicate that vertebrates fundamentally have two types of the proteins participating in transduction in vertebrate visual cells ; cone type and rod type.
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