Degration and removal of the proteins in photosystem II during photoinhibition

光抑制过程中光系统 II 中蛋白质的降解和去除

• 批准号: 08836007
• 负责人: YAMAMOTO Yasusi
• 金额: $ 1.47万
• 依托单位: OKAYAMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08836007/
• 关键词: photosynthesis; photosystem II; photoinhibition; DI protein; turn-over; plant physiology; active oxygen; rodical

When plants are illuminated with strong light, photoinhibition of photosynthesis takes place. The target of photoinhibition is photosystem II.In the present study, damage, degradation and recovery processes of the reaction-center binding D1 protein in photosystem II during light stress were studied with spinach PS II membranes, PS II core samples and Chlamydomonas cells. The results obtained are as follows ;(1) An extrinsic 33 kDa protein of photosystem II regulates the damage-degradation step of the D1 protein. The 33-kDa protein decreases the aggregation of D1 and at the same time enhances the degradation of D1.(2) Active oxygen molecules are involved in the degradation of D1 not only in the reducing-side photoinhibition, but also in the donor-side photoinhibition.(3) A large conformational change cn be detected by FTIR under the illumination of the PS II samples with strong light, but no siggnificant structural changes in PS II was found in hydrogen peroxide treatment of the PS II samples.

当植物受到强光照射时，光合作用发生光抑制。光抑制的目标是光系统II。本研究以菠菜PS II膜、PS II核心样品和衣藻细胞为材料，研究了光系统II反应中心结合D1蛋白在光胁迫下的损伤、降解和恢复过程。所得结果如下：(1)光系统II外源33 kDa蛋白调控D1蛋白的损伤降解步骤。33kda蛋白降低了D1的聚集，同时增强了D1的降解。(2)活性氧分子不仅参与还原性侧光抑制，还参与供体侧光抑制。(3)在强光照射下，FTIR可以检测到PS II样品有较大的构象变化，而过氧化氢处理的PS II样品没有发现明显的结构变化。

项目成果

Hashimoto, A.: "Unassembled subunits of the photosynthetic oxygen-evolving complex present in the thylakoind lumen are long-lived and assembly-competent." FEBS Letters. 391. 29-34 (1996)

Hashimoto, A.：“类囊体管腔中存在的光合释氧复合物的未组装亚基寿命较长且具有组装能力。”

Yamamoto, Y.: "The role of an extrinsic 33 kDa protein of photosystem II in the turnover of the yeastion-center binding protein D1 during photoinhibition" Biochemistry. (印刷中). (1998)

Yamamoto, Y.：“光系统 II 的外在 33 kDa 蛋白在光抑制过程中酵母中心结合蛋白 D1 的周转中的作用”生物化学（1998 年出版）。

Hashimoto, A.: "In organello assembly of newly imported oxygen-evolving complex subunits in isolated chloroplsts." The Plant Cell. 9. 441-452 (1997)

Hashimoto, A.：“在分离的叶绿体中新导入的释氧复杂亚基的细胞器组装中。”

Hashimoto,A.: "Unassembled subunits of the photosynthetic oxygen-evolving complex present in the thylakoid lumeu and long-lived and assembly-competent." FEBS Letters. 391. 29-34 (1996)

Hashimoto,A.：“类囊体腔中存在光合释氧复合物的未组装亚基，寿命长且具有组装能力。”

Hashimoto,A.: "In organello assembly of newly imported oxygen-evolving complex subunits in isolated chloroplasts." The Plant Cell. (印刷中). (1997)

Hashimoto, A.：“在分离的叶绿体中新导入的释氧复合亚基的细胞器组装”（正在出版）。