Revised Morning Loops of the Arabidopsis Circadian Clock Based on Analyses of Direct Regulatory Interactions.
Revised Morning Loops of the Arabidopsis Circadian Clock Based on Analyses of Direct Regulatory Interactions.
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DOI：
10.1371/journal.pone.0143943
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Carré IA
中科院分区：
文献类型：
--
作者：
Adams S;Manfield I;Stockley P;Carré IA
植物生物钟的网络结构是复杂的，单个成分之间的直接调控相互作用已被证明特别难以从遗传分析中预测。在这里，我们系统地研究了早晨特异性转录因子LATE ELONGATED HYPOCOTYL （LHY）与该网络其他组分启动子之间的体内结合相互作用。然后，我们通过测试靶基因对乙醇诱导的LHY蛋白表达水平变化的响应性来证明这些相互作用的功能。我们发现了LHY和密切相关的CIRCADIAN CLOCK ASSOCIATED-1 （CCA1）对自身和彼此表达的新的负自我调节反馈回路。此外，我们表明LHY作为所有其他时钟成分的抑制因子，包括伪响应调节因子（PRRs） 9和7，它们以前被认为是积极的调节靶标。这些实验结果导致了对时钟早晨循环的实质性修订。
The network structure of the plant circadian clock is complex and direct regulatory interactions between individual components have proven particularly difficult to predict from genetic analyses. Here, we systematically investigate in vivo binding interactions between the morning-specific transcription factor, LATE ELONGATED HYPOCOTYL (LHY) and the promoters of other components of the network. We then demonstrate the functionality of these interactions by testing the responsiveness of the target gene to an ethanol-induced change in expression level of the LHY protein. We uncover novel, negative autoregulatory feedback loops from LHY and the closely related CIRCADIAN CLOCK ASSOCIATED-1 (CCA1) onto their own and each other’s expression. Furthermore we show that LHY acts as a repressor of all other clock components, including PSEUDO-RESPONSE REGULATORs (PRRs) 9 and 7, which were previously thought to be positive regulatory targets. These experimental results lead to a substantial revision of the morning loops of the clock.