Singlet oxygen inhibits the repair of photosystem II by suppressing the translation elongation of the D1 protein in Synechocystis sp PCC 6803
Singlet oxygen inhibits the repair of photosystem II by suppressing the translation elongation of the D1 protein in Synechocystis sp PCC 6803
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DOI：
10.1021/bi036178q
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发表时间：
2004-09-07
期刊：
影响因子：
2.9
通讯作者：
Murata, N
中科院分区：
文献类型：
--
作者：
Nishiyama, Y;Allakhverdiev, SI;Murata, N
在光合作用过程中产生的单线态氧是一种强氧化剂，可能会破坏各种具有生物重要性的分子。我们研究了单线态氧对蓝细菌集胞藻6803光系统II（PSII）光损伤的影响。增加细胞内的单线态氧浓度，引起的光敏剂，如玫瑰红和乙基曙红的存在下，刺激了明显的光损伤PSII。然而，实际的光损伤PSII，在氯霉素的存在下进行评估，是不受单线态氧的生产。这些观察结果表明，单线态氧所产生的添加光敏剂的行为，通过抑制光损伤的PSII修复。在体内的蛋白质标记显示，单线态氧抑制蛋白质从头合成，特别是D1蛋白的合成。北方印迹分析表明，积累的psbA mRNA，编码的D1蛋白，不受单线态氧的生产。与绑定psbA mRNA的多核糖体的亚细胞定位表明，单线态氧的主要目标可能是翻译的延伸步骤。
Singlet oxygen, generated during photosynthesis, is a strong oxidant that can, potentially, damage various molecules of biological importance. We investigated the effects in vivo of singlet oxygen on the photodamage to photosystem II (PSII) in the cyanobacterium Synechocystis sp. PCC 6803. Increases in intracellular concentrations of singlet oxygen, caused by the presence of photosensitizers, such as rose bengal and ethyl eosin, stimulated the apparent photodamage to PSII. However, actual photodamage to PSII, as assessed in the presence of chloramphenicol, was unaffected by the production of singlet oxygen. These observations suggest that singlet oxygen produced by added photo sensitizers acts by inhibiting the repair of photodamaged PSII. Labeling of proteins in vivo revealed that singlet oxygen inhibited the synthesis of proteins de novo and, in particular, the synthesis of the D1 protein. Northern blotting analysis indicated that the accumulation of psbA mRNAs, which encode the D1 protein, was unaffected by the production of singlet oxygen. Subcellular localization of polysomes with bound psbA mRNAs suggested that the primary target of singlet oxygen might be the elongation step of translation.