No transcription-translation feedback in circadian rhythm of KaiC phosphorylation
No transcription-translation feedback in circadian rhythm of KaiC phosphorylation
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DOI：
10.1126/science.1102540
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发表时间：
2005-01-14
期刊：
影响因子：
56.9
通讯作者：
Iwasaki, H
中科院分区：
文献类型：
--
作者：
Tomita, J;Nakajima, M;Iwasaki, H
一个自动调节转录翻译反馈环被认为是必不可少的，在任何模式生物产生昼夜节律。在蓝细菌Synechococcus elongatus中，必需的时钟蛋白KaiC被提出形成这种类型的转录负反馈。然而，我们在此证明了KaiC磷酸化的温度补偿的、稳健的昼夜节律循环，即使在连续黑暗条件下没有kaiBC信使RNA积累。这种节奏持续存在的转录或翻译抑制剂。此外，KaiC自磷酸化-去磷酸化比率的动力学曲线在体外也是温度补偿的。因此，蓝藻时钟可以保持时间独立的从头转录。和翻译过程。
An autoregulatory transcription-translation feedback loop is thought to be essential in generating circadian rhythms in any model organism. In the cyanobacterium Synechococcus elongatus, the essential clock protein KaiC is proposed to form this type of transcriptional negative feedback. Nevertheless, we demonstrate here temperature-compensated, robust circadian cycling of KaiC phosphorylation even without kaiBC messenger RNA accumulation under continuous dark conditions. This rhythm persisted in the presence of a transcription or translation inhibitor. Moreover, kinetic profiles in the ratio of KaiC autophosphorylation-dephosphorylation were also temperature compensated in vitro. Thus, the cyanobacterial clock can keep time independent of de novo transcription. and translation processes.