A novel high light-inducible carotenoid-binding protein complex in the thylakoid membranes of Synechocystis PCC 6803.
A novel high light-inducible carotenoid-binding protein complex in the thylakoid membranes of Synechocystis PCC 6803.
复制标题
集胞藻 PCC 6803 类囊体膜中的新型高光诱导类胡萝卜素结合蛋白复合物
DOI：
10.1038/srep09480
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发表时间：
2015-03-30
影响因子：
4.6
通讯作者：
Wang Q
中科院分区：
文献类型：
--
作者：
Daddy S;Zhan J;Jantaro S;He C;He Q;Wang Q
聚球藻。PCC 6803是一种被广泛应用于光合作用研究的蓝藻模型。在这里，我们揭示了一种新的高光诱导类胡萝卜素结合蛋白复合体(HLCC)，它位于聚球藻PCC6803细胞的类囊体膜上，受到高光照射。玉米黄质和粘黄素分别占与该复合体结合的类胡萝卜素的29.8%和54.8%。用Blue-Native PAGE、2D-SDS-PAGE和MS分析表明，HLCC由Slr1128、ISIA、PSAD和HliA/B组成，并通过SEAD荧光交联和抗PSAD免疫共沉淀分析证实了这一结果。高光照射和人工氧化胁迫增强了HLCC蛋白质组分编码基因的表达。这些蛋白的缺失导致状态转换受损，并增加了对氧化和/或强光胁迫的敏感性，这表明膜过氧化作用增加。因此，HLCC保护类囊体膜免受广泛的光氧化损伤，可能是通过一种涉及状态转换的机制。
Synechocystis sp. PCC 6803 is a model cyanobacterium extensively used to study photosynthesis. Here we reveal a novel high light-inducible carotenoid-binding protein complex (HLCC) in the thylakoid membranes of Synechocystis PCC 6803 cells exposed to high intensity light. Zeaxanthin and myxoxanthophyll accounted for 29.8% and 54.8%, respectively, of the carotenoids bound to the complex. Using Blue-Native PAGE followed by 2D SDS-PAGE and mass spectrometry, we showed that the HLCC consisted of Slr1128, IsiA, PsaD and HliA/B. We confirmed these findings by SEAD fluorescence cross-linking and anti-PsaD immuno-coprecipitation analyses. The expression of genes encoding the protein components of the HLCC was enhanced by high light illumination and artificial oxidative stress. Deletion of these proteins resulted in impaired state transition and increased sensitivity to oxidative and/or high light stress, as indicated by increased membrane peroxidation. Therefore, the HLCC protects thylakoid membranes from extensive photooxidative damage, likely via a mechanism involving state transition.