Loss of the circadian clock-associated protein I in Arabidopsis results in altered clock-regulated gene expression
Loss of the circadian clock-associated protein I in Arabidopsis results in altered clock-regulated gene expression
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DOI：
10.1073/pnas.96.7.4176
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发表时间：
1999-03-30
影响因子：
11.1
通讯作者：
Tobin, EM
中科院分区：
文献类型：
--
作者：
Green, RM;Tobin, EM
尽管植物昼夜节律振荡器对无根植物非常重要，但人们对它们知之甚少，因为无根植物需要精确的计时器，才能使植物对环境做出反应。之前，我们发现了一个生物钟相关（CCA1）基因，该基因编码myb相关蛋白，该蛋白与植物的光敏色素控制和昼夜节律调节有关。为了了解CCA1在光光色素和昼夜节律调节中的作用，我们分离了一个T DNA插入的拟南芥品系，该品系导致CCA1 RNA、CCA1蛋白和lhcb启动子结合活性的丧失。这种突变影响了我们所研究的所有四个时钟控制基因的昼夜节律表达。结果表明，尽管CCA1和LIIY相似，但它们只是部分冗余。CCA1的缺乏也会影响光敏色素对基因表达的调节，这表明CCA1在光信号转导途径中具有额外的作用，可能在光敏色素和时钟之间的整合点起作用。我们的研究结果表明，CCA1是一个重要的时钟相关蛋白，参与基因表达的昼夜调节。
Little is known about plant circadian oscillators, in spite of how important they are to sessile plants, which require accurate timekeepers that enable the plants to respond to their environment. Previously, we identified a circadian clock-associated (CCA1) gene that encodes an Myb-related protein that is associated with phytochrome control and circadian regulation in plants. To understand the role CCA1 plays in phytochrome and circadian regulation, we have isolated an Arabidopsis line with a T DNA insertion that results in the loss of CCA1 RNA, of CCA1 protein, and of an Lhcb-promoter binding activity. This mutation affects the circadian expression of all four clock controlled genes that we examined. The results show that, despite their similarity, CCA1 and LIIY are only partially redundant. The lack of CCA1 also affects the phytochrome regulation of gene expression, suggesting that CCA1 has an additional role in a signal transduction pathway from light, possibly acting at the point of integration between phytochrome and the clock Our results indicate that CCA1 is an important clock-associated protein involved in circadian regulation of gene expression.