Functioning and robustness of a bacterial circadian clock.
Functioning and robustness of a bacterial circadian clock.
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DOI：
10.1038/msb4100128
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发表时间：
2007
影响因子：
9.9
通讯作者：
Kollmann, Markus
中科院分区：
文献类型：
--
作者：
Clodong, Sebastien;Duhring, Ulf;Kronk, Luiza;Wilde, Annegret;Axmann, Ilka;Herzel, Hanspeter;Kollmann, Markus
蓝藻是已知的最简单的细胞系统，在日常周期中调节其生物活动。对于蓝细菌细长聚球藻（Synechococcus elongatus），已经通过体外和体内实验表明，基本的昼夜节律计时过程基于KaiC六聚体的节律性磷酸化。尽管有出色的实验工作，但仍然缺乏对体外时钟的完整系统水平的理解。在这项工作中，我们提供了一种数学方法来扫描不同的假设机制的主要昼夜节律振荡器，从实验建立的分子特性的时钟蛋白。尽管针对最高性能进行了优化，但只有一个计算机生成的反应网络能够重现实验发现的高振幅和对扰动的鲁棒性。在这个反应网络中，负反馈使各个六聚体的磷酸化水平同步，并且确实在S.实验证实了KaiA螯合作用对长形核壳菌的影响。
Cyanobacteria are the simplest known cellular systems that regulate their biological activities in daily cycles. For the cyanobacterium Synechococcus elongatus, it has been shown by in vitro and in vivo experiments that the basic circadian timing process is based on rhythmic phosphorylation of KaiC hexamers. Despite the excellent experimental work, a full systems level understanding of the in vitro clock is still lacking. In this work, we provide a mathematical approach to scan different hypothetical mechanisms for the primary circadian oscillator, starting from experimentally established molecular properties of the clock proteins. Although optimised for highest performance, only one of the in silico-generated reaction networks was able to reproduce the experimentally found high amplitude and robustness against perturbations. In this reaction network, a negative feedback synchronises the phosphorylation level of the individual hexamers and has indeed been realised in S. elongatus by KaiA sequestration as confirmed by experiments.