1997 Fiscal Year Final Research Report Summary
Joint study on the search for phytochrome binding proteins
| Project/Area Number |
09044232
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Field |
植物生理
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| Research Institution | TOKYO METROPOLITAN UNIVERSITY |
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Principal Investigator |
WADA Masamitsu Tokyo Metropolitan University, Biology., Professor, 理学研究科, 教授 (60011681)
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| Co-Investigator(Kenkyū-buntansha) |
JANE Silvert カリフォルニア大(サンタクルツ校), 生物, 準教授
ELMAR Hartmann Berlin Free Univ., Plant Physiol., Professor, 植物生理微生物, 教授
CLARK Lagati カリフォルニア大(デービス校), 生化生物物理, 教授
KANEGAE Takeshi Tokyo Metropolitan Univ.Biol., Asistant Professor, 大学院・理学研究科, 助手 (70264588)
KADOTA Akeo Tokyo Metropolitan Univ., Biology, Associate Professor, 大学院・理学研究科, 助教授 (60152758)
CLARK Lagarias.J. Univ.California Davis, Biochem.Professor
JANE Siverthorne Univ.California, Santa Cruz., Associate Professor
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| Project Period (FY) |
1997
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| Keywords | Phytochrome / Fern / Moss / Adiantum / Ceratodon / Lhcb / Gene expression |
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| Research Abstract |
We identified 4 phytochrome genes (Adiantum phyl1-4) from Adiatum genomic library. One of them (phy3) was a novel photoreceptor gene whose putative polypeptide has a phytochrome chromophore-binding domain, that is tethered to a large polypeptide related to the NPH1 protein which is a key component in seed plant phototropism. Apoprotein expressed in yeasts was reconstituted with a chromophore precursor phycocyanobilin. Zinc blot analysis and spectrophotometric experiments suggested that the Adiantum PHY3 was a functional phytochrome. C-terminal domain of PHY3 possesses two LOV domains, followed by Ser/Thr protein kinase (PK) domain. The LOV domain has been proposed to have flavin binding site, meaning tht PHY3 may absorb red/farred and blue light. The Ser/Thr PK domain of Adaintum PHY3 has all of the essential subdomains and conserved amino acids of Ser/Thr PKs, suggesting that this kinase activity is light-regulated. We tested protein kinase activity using full length PHY3 polypeptides expressed in yeasts and also using kinase part expressed in E.coli. However, we do not detect the activity so far.
To find a binding protein to this PHY3 polypeptide, we are trying two-hybrid system. We do not find any candidate at the moment.
We studied phytochrome dependent gene expression in Adiantum gametophtyes as well as in sporophytes, and found taht expression of Lhcb gene (s) of Adiantum is light regulated as in higher plants, however very low fluence rate response could not be detected in this fern.
Phytochrome-mediated branch formation and curling growth of Ceratodon protoenemata were also studied. These results strongly reconfirmed dichroic localization of phytochrome in Ceratodon protonemata.
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Research Products
(8 results)
