| Project/Area Number |
17570040
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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 |
植物生理・分子
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| Research Institution | Ehime University |
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Principal Investigator |
NISHIYAMA Yoshitaka Ehime University, Cell-Free Science and Technology Research Center, Associate Professor, 無細胞生命科学工学研究センター, 助教授 (30281588)
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| Co-Investigator(Kenkyū-buntansha) |
TOZAWA Yuzuru Ehime University, Cell-Free Science and Technology Research Center, Professor, 無細胞生命科学工学研究センター, 教授 (90363267)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Photosynthesis / Photosystem II / Repair / Oxidative stress / Protein synthesis / In vitro translation / Elongation factor / Cyanobacteria |
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| Research Abstract |
Ph00otoinhibition of photosystem II (PSII) is due to the imbalance between the rate of photodamage to PSII and the rate of the repair of damaged PSII. Photodamage is initiated by the direct effects of light on the oxygen-evolving complex and, thus, photodamage to PSII is unavoidable. Studies of the effects of oxidative stress on photodamage and subsequent repair have revealed that reactive oxygen species (ROS) act primarily by inhibiting the repair of photodamaged PSII and not by damaging PSII directly. Thus, strong light has dual effects on PSII ; it damages PSII directly and it inhibits the repair of PSII via production of ROS. Investigations of the ROS-induced inhibition of repair have demonstrated that ROS suppress the synthesis de novo of proteins that are required for the repair of PSII, such as the D1 protein. Moreover, analysis of polysomes has determined that a primary target for inhibition by ROS is the elongation step of translation. Investigations using a cyanobacterial translation system in vitro have revealed that elongation factor G might be the primary target, within the translational machinery, of inhibition by ROS. Here we present a new paradigm for the molecular action of ROS in photoinhibition.
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