| Project/Area Number |
18K06275
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 44030:Plant molecular biology and physiology-related
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| Research Institution | Saitama University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
西山 佳孝 埼玉大学, 理工学研究科, 教授 (30281588)
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| Project Period (FY) |
2018-04-01 – 2023-03-31
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| Project Status |
Completed (Fiscal Year 2022)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2018: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
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| Keywords | 光化学系I / チラコイド膜タンパク質 / 電子伝達 / クラミドモナス / 光阻害 / PGRL1タンパク質 / 光合成 / 光化学系 / Photosystme I |
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| Outline of Final Research Achievements |
A thylakoid membrane protein, PGRL1 contains six cysteine residues conserved from green algae to land plants. In PGRL1-deficient mutant (pgrl1), photosystem I (PSI) is sensitive to inactivation under the strong light. To reveal the mechanism by which PGRL1 protects PSI against strong light in Chlamydomonas, we generated the complemented strains and the strains substituted from cysteine to serine residues in PGRL1 (CS variants). Under strong light, the activity of PSI in C63SC1673 variant was remained high, but the activity in C256SC269S and C284SC287S variants declined, as observed in pgrl1. Based on our results, the substitutions affected the PSI photoprotection more severely than lowering the level of PGRL1, though some CS variants showed lower accumulation of PGRL1. Thus, the cysteine residues in the C-terminal region of PGRL1 seems to play important roles in protecting PSI under strong light.
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| Academic Significance and Societal Importance of the Research Achievements |
光は光合成に必要であるが、強い光は細胞内での活性酸素種の発生を引き起こすなど有害なストレスとなる。二つの光化学系のうち(PSI, PSII)、PSIIは強光ストレスに弱く容易に失活する一方、PSIは強光下でも活性を維持することが知られていたため、PSI光阻害については研究報告はかなり限られていた。本研究では、PGRL1タンパク質及びそのC末端部位に保存されるシステイン残基がPSIの活性維持に果たす役割を明らかになり、PSI活性維持メカニズムの解明の一旦を担った。光阻害の予防は農学的にも重要であるため、本研究成果は育種等の応用に向けた分子基盤を提供できる可能性がある。
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