Response to oxidative stress involves a novel peroxiredoxin gene in the unicellular cyanobacterium Synechocystis sp PCC 6803
Response to oxidative stress involves a novel peroxiredoxin gene in the unicellular cyanobacterium Synechocystis sp PCC 6803
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DOI：
10.1093/pcp/pch034
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发表时间：
2004-03-01
影响因子：
4.9
通讯作者：
Ikeuchi, M
中科院分区：
文献类型：
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作者：
Kobayashi, M;Ishizuka, T;Ikeuchi, M
甲基紫精在光照条件下会促进超氧化物的产生，从而严重损害蓝细菌和植物的光合机构以及许多细胞过程。采用基因芯片技术研究了甲基紫精对单细胞蓝藻集胞藻PCC 6803基因表达的影响。甲基紫精处理15 min后，在正常光照和强光条件下，sll 1621、slr 1738、slr 0074、slr 0075和slr 0589的开放阅读框均被显著诱导。这些基因之一，slr1738，它编码的铁摄取阻遏物（Fur）型转录调节因子，位于分歧旁边的另一个诱导基因，sll 1621，在基因组中。我们删除了slr1738，并在非应激条件下比较了该突变体与野生型的全局基因表达模式。结果发现，sll1621是去阻遏到最大程度，而许多其他基因，包括slr0589，但不是slr0074或slr0075在突变体中的去阻遏程度较低。sll1621编码一个2型过氧化物氧还蛋白，其基因突变表明sll1621在强光下的液体和固体培养基中以及在弱光下的固体培养基中对好氧光合生长都是必不可少的。将slr1738制备为His标记的重组蛋白，并显示其特异性结合sll1621和slr1738之间的基因间区域。二硫苏糖醇增强结合，过氧化氢消除结合。我们的结论是，毛皮同源物，SLR1738，起着调节作用，在诱导一个有效的抗氧化基因，SLL 1621，在氧化应激反应。
Exposure to methyl viologen in the presence of light facilitates the production of superoxide that gives severe damage on photosynthetic apparatus as well as many cellular processes in cyanobacteria and plants. The effects of methyl viologen on global gene expression of a unicellular cyanobacterium Synechocystis sp. strain PCC 6803 were determined by DNA microarray. The ORFs sll1621, slr1738, slr0074, slr0075, and slr0589 were significantly induced by treatment of methyl viologen for 15 min commonly under conditions of normal and high light. One of these genes, slr1738, which encodes a ferric uptake repressor (Fur)-type transcriptional regulator, is located divergently next to another induced gene, sll1621, in the genome. We deleted slr1738, and compared the global gene expression patterns of this mutant to that of wild type under non-stressed conditions. It was found that sll1621 was derepressed to the greatest extent, while many other genes including slr0589 but not slr0074 or slr0075 were derepressed to lesser extent in the mutant. Genetic disruption of sll1621, which encodes a putative type 2 peroxiredoxin, indicates that it is essential for aerobic phototrophic growth in both liquid and solid media in high light and on solid medium even in low light. Slr1738 was prepared as a His-tagged recombinant protein and shown to specifically bind to the intergenic region between sll1621 and slr1738. The binding was enhanced by dithiothreitol and abolished by hydrogen peroxide. We concluded that the Fur homolog, Slr1738, plays a regulatory role in the induction of a potent antioxidant gene, sll1621, in response to oxidative stress.