A new promoter element associated with daily time keeping in Drosophila.
A new promoter element associated with daily time keeping in Drosophila.
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DOI：
10.1093/nar/gkx268
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发表时间：
2017-06-20
影响因子：
14.9
通讯作者：
Wijnen H
中科院分区：
文献类型：
--
作者：
Sharp B;Paquet E;Naef F;Bafna A;Wijnen H
生物钟是一种自主的日常计时机制，允许生物体适应环境节奏并在时间上组织生物功能。时钟控制的计时涉及到节奏基因表达的广泛调节。迄今为止，相对较少的时钟相关的启动子元件已被确定和表征。在对12种果蝇的核心时钟基因启动子的无偏搜索中，我们发现了一个29 bp的共有序列，我们将其命名为时钟相关转录激活盒或“CATAC”。为了实验性地解决与该元件相关的时空表达信息，我们产生了具有驱动酵母Gal 4或萤火虫荧光素酶报告基因表达的基础启动子上游的四个单独的天然CATAC元件的构建体。报告基因分析表明，野生型，但不是突变的CATAC元件的存在下，赋予增加的表达水平以及节奏调节。CATAC共有序列的一部分类似于核心昼夜节律转录因子CLOCK/CYCLE（CLK/CYC）的E盒结合位点，并且在cyc或编码CLK/CYC抑制剂的基因中存在无效突变的情况下，CATAC介导的表达节律丢失，周期（per）。然而，我们的研究结果表明，在没有CLK/CYC的情况下，CATAC的增强子功能仍然存在。因此，CATAC代表了一种新的顺式调控元件编码的时钟控制的调节。
Circadian clocks are autonomous daily timekeeping mechanisms that allow organisms to adapt to environmental rhythms as well as temporally organize biological functions. Clock-controlled timekeeping involves extensive regulation of rhythmic gene expression. To date, relatively few clock-associated promoter elements have been identified and characterized. In an unbiased search of core clock gene promoters from 12 species of Drosophila, we discovered a 29-bp consensus sequence that we designated as the Clock-Associated Transcriptional Activation Cassette or ‘CATAC’. To experimentally address the spatiotemporal expression information associated with this element, we generated constructs with four separate native CATAC elements upstream of a basal promoter driving expression of either the yeast Gal4 or firefly luciferase reporter genes. Reporter assays showed that presence of wild-type, but not mutated CATAC elements, imparted increased expression levels as well as rhythmic regulation. Part of the CATAC consensus sequence resembles the E-box binding site for the core circadian transcription factor CLOCK/CYCLE (CLK/CYC), and CATAC-mediated expression rhythms are lost in the presence of null mutations in either cyc or the gene encoding the CLK/CYC inhibitor, period (per). Nevertheless, our results indicate that CATAC's enhancer function persists in the absence of CLK/CYC. Thus, CATAC represents a novel cis-regulatory element encoding clock-controlled regulation.