Neurospora wc-1 and wc-2: Transcription, photoresponses, and the origins of circadian rhythmicity
Neurospora wc-1 and wc-2: Transcription, photoresponses, and the origins of circadian rhythmicity
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DOI：
10.1126/science.276.5313.763
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发表时间：
1997-05-02
期刊：
影响因子：
56.9
通讯作者：
Loros, JJ
中科院分区：
文献类型：
--
作者：
Crosthwaite, SK;Dunlap, JC;Loros, JJ
昼夜节律性普遍与感知光的能力有关，而产生这些节律的振荡器（“时钟”）是基于转录和翻译的反馈回路，由光重置。虽然这样的循环必须包含积极和消极的调控元素，时钟基因分析日期-frq在脉孢菌和每和蒂姆在果蝇-仅与负反馈和他们的生化功能在很大程度上推断。白色collar-1和白色collar-2基因都是脉孢菌属中光反应的全局调节因子，编码含有PAS结构域的DNA结合蛋白，并被认为是转录激活因子。这里显示的数据表明，wc-1是一个时钟相关的基因和wc-2是一个时钟组件，都发挥重要作用的组装或操作的脉孢菌昼夜振荡器。因此，DNA结合和转录激活现在可以与时钟基因相关联，时钟基因可以在反馈回路中提供积极的元件。此外，PAS结构域区域的分子参与光感知和昼夜节律在几种生物体之间的相似性表明，古老的感光蛋白和更现代的昼夜振荡所需的蛋白质之间的进化联系。
Circadian rhythmicity is universally associated with the ability to perceive light, and the oscillators (''clocks'') giving rise to these rhythms, which are feedback loops based on transcription and translation, are reset by light. Although such loops must contain elements of positive and negative regulation, the clock genes analyzed to date-frq in Neurospora and per and tim in Drosophila-are associated only with negative feedback and their biochemical functions are largely inferred. The white collar-1 and white collar-2 genes, both global regulators of photoresponses in Neurospora, encode DNA binding proteins that contain PAS domains and are believed to act as transcriptional activators. Data shown here suggest that wc-1 is a clock-associated gene and wc-2 is a clock component; both play essential roles in the assembly or operation of the Neurospora circadian oscillator. Thus DNA binding and transcriptional activation can now be associated with a clock gene that may provide a positive element in the feedback loop. In addition, similarities between the PAS-domain regions of molecules involved in light perception and circadian rhythmicity in several organisms suggest an evolutionary link between ancient photoreceptor proteins and more modern proteins required for circadian oscillation.