Time-of-day-dependent responses of cyanobacterial cellular viability against oxidative stress.
Time-of-day-dependent responses of cyanobacterial cellular viability against oxidative stress.
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DOI：
10.1038/s41598-020-77141-8
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发表时间：
2020-11-18
影响因子：
4.6
通讯作者：
Nakanishi S
中科院分区：
文献类型：
--
作者：
Tanaka K;Shimakawa G;Nakanishi S
作为对环境光周期性波动的一种适应，光合生物进化出了生物钟。生物钟对许多细胞生理功能的控制，包括抗氧化酶、代谢和细胞周期，在氧化应激耐受的背景下引起了人们的注意。然而，由于每种生理功能都以综合的方式处理氧化应激，因此细胞对氧化应激的反应是否受到昼夜节律的控制仍然是一个悬而未决的问题。事实上，氧化应激耐受的昼夜节律尚未得到实验证明。在目前的工作中，我们应用了一种测定甲基紫精（MV），它产生活性氧（ROS）在光照射下，并通过实验验证了氧化应激耐受性的昼夜节律的光合细胞的蓝细菌细长聚球藻PCC 7942，一个标准的模式物种的生物钟的调查。在这里，我们报告说，由MV处理产生的ROS导致基质成分的损害，而不是光合电子传递链，导致细胞活力降低。细胞活力降低的程度取决于施加氧化应激的主观时间。因此，氧化应激耐受性显示出昼夜节律。此外，氧化应激耐受的节律模式在缺乏必需的时钟基因的突变细胞中消失。值得注意的是，ROS水平周期性变化，独立于MV处理。因此，我们首次证明，在蓝藻细胞，氧化应激耐受性显示昼夜振荡。
As an adaptation to periodic fluctuations of environmental light, photosynthetic organisms have evolved a circadian clock. Control by the circadian clock of many cellular physiological functions, including antioxidant enzymes, metabolism and the cell cycle, has attracted attention in the context of oxidative stress tolerance. However, since each physiological function works in an integrated manner to deal with oxidative stress, whether or not cell responses to oxidative stress are under circadian control remains an open question. In fact, circadian rhythms of oxidative stress tolerance have not yet been experimentally demonstrated. In the present work, we applied an assay using methyl viologen (MV), which generates reactive oxygen species (ROS) under light irradiation, and experimentally verified the circadian rhythms of oxidative stress tolerance in photosynthetic cells of the cyanobacterium Synechococcus elongatus PCC 7942, a standard model species for investigation of the circadian clock. Here, we report that ROS generated by MV treatment causes damage to stroma components and not to the photosynthetic electron transportation chain, leading to reduced cell viability. The degree of decrease in cell viability was dependent on the subjective time at which oxidative stress was applied. Thus, oxidative stress tolerance was shown to exhibit circadian rhythms. In addition, the rhythmic pattern of oxidative stress tolerance disappeared in mutant cells lacking the essential clock genes. Notably, ROS levels changed periodically, independent of the MV treatment. Thus, we demonstrate for the first time that in cyanobacterial cells, oxidative stress tolerance shows circadian oscillation.
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DOI：
10.1038/nrmicro.2016.196
发表时间：
2017-04
期刊：
Nature reviews. Microbiology
影响因子：
--
作者：
Johnson CH;Zhao C;Xu Y;Mori T
通讯作者：
Mori T
DOI：
10.1016/0005-2728(73)90121-7
发表时间：
1973-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
FARRINGTON, JA;EBERT, M;FLETCHER, K
通讯作者：
FLETCHER, K
影响因子：
7.4
作者：
Desimone, M;Henke, A;Wagner, E
通讯作者：
Wagner, E
影响因子：
7.4
作者：
BABBS, CF;PHAM, JA;COOLBAUGH, RC
通讯作者：
COOLBAUGH, RC
影响因子：
4.9
作者：
Hakkila, Kaisa;Valev, Dimitar;Tyystjarvi, Taina
通讯作者：
Tyystjarvi, Taina