Control of electron transport routes through redox-regulated redistribution of respiratory complexes
Control of electron transport routes through redox-regulated redistribution of respiratory complexes
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通过氧化还原调节的呼吸复合物的重新分布来控制电子传输途径
DOI：
10.1016/j.bbabio.2012.06.366
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Liu L
中科院分区：
文献类型：
--
作者：
Liu L
在蓝藻中，呼吸电子传递发生在光合电子传递附近，因为这两个过程所需的复合物位于类囊体膜内。电子传递途径的平衡对细胞生理学至关重要，但控制特定途径优势的因素知之甚少。在这里，我们使用绿色荧光蛋白标记和共聚焦荧光显微镜在蓝藻Synechococcus elongatusPCC 7942的活细胞的组合，调查两个关键的呼吸电子供体，I型NAD（P）H脱氢酶（NDH-1）和琥珀酸脱氢酶（SDH）的亚微米尺度上的分布。当细胞在弱光下生长时，两种复合物都集中在类囊体膜上的离散斑块中，直径约为100-300 nm，含有数十至数百个复合物。暴露于适度的光导致NDH-1和SDH的重新分布，使得它们均匀地分布在类囊体膜内。电子传递抑制剂的影响表明，呼吸复合物的再分配是由接近质体醌的电子载体的氧化还原状态的变化引发的。重新分配不依赖于从头蛋白质合成，它是伴随着呼吸电子转移到光系统I，而不是一个终端氧化酶的概率大幅增加。这些结果表明，在100-300 nm的尺度上的复合物的分布控制的还原能力的分配和这些尺度上的电子传递复合物的重新分配是一种生理机制，以调节电子流的途径。
In cyanobacteria, respiratory electron transport takes place in close proximity to photosynthetic electron transport, because the complexes required for both processes are located within the thylakoid membranes. The balance of electron transport routes is crucial for cell physiology, yet the factors that control the predominance of particular pathways are poorly understood. Here we use a combination of tagging with green fluorescent protein and confocal fluorescence microscopy in live cells of the cyanobacteriumSynechococcus elongatusPCC 7942 to investigate the distribution on submicron scales of two key respiratory electron donors, type-I NAD(P)H dehydrogenase (NDH-1) and succinate dehydrogenase (SDH). When cells are grown under low light, both complexes are concentrated in discrete patches in the thylakoid membranes, about 100–300 nm in diameter and containing tens to hundreds of complexes. Exposure to moderate light leads to redistribution of both NDH-1 and SDH such that they become evenly distributed within the thylakoid membranes. The effects of electron transport inhibitors indicate that redistribution of respiratory complexes is triggered by changes in the redox state of an electron carrier close to plastoquinone. Redistribution does not depend on de novo protein synthesis, and it is accompanied by a major increase in the probability that respiratory electrons are transferred to photosystem I rather than to a terminal oxidase. These results indicate that the distribution of complexes on the scale of 100–300 nm controls the partitioning of reducing power and that redistribution of electron transport complexes on these scales is a physiological mechanism to regulate the pathways of electron flow.
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影响因子：
4.8
作者：
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作者：
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通讯作者：
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作者：
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通讯作者：
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影响因子：
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作者：
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DOI：
10.1007/978-1-4020-4061-0_12
发表时间：
2007
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
P. Nixon;P. Rich
通讯作者：
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