Post-translational control mechanisms of the circadian clock

 描述(申请人提供)：昼夜节律是几乎无处不在的内源性计时系统，有助于协调在一天中的所有时间在每个生物体中连续发生的无数生理、代谢和发育过程。这个生物钟由分子水平的互锁和自动调节反馈环组成，这些反馈环是由复杂的相互作用构建的，这些相互作用在整个24小时周期中与每个相互作用不断变化。这个项目的长期目标是了解维持昼夜节律振荡器运行的转录后过程之间的功能关系。我们正在利用模式植物拟南芥的遗传、基因组、生化和细胞生物学工具和策略来确定调控重要蛋白质和mRNA在细胞质和细胞核之间运输的分子和机制。我们在一定程度上关注了时钟蛋白的一系列翻译后修饰如何影响它们的位置和时间细胞内定位。细胞内环境的把关特征也将在基因组和单一分子物种的水平上得到解决。我们首次在昼夜节律研究中应用单细胞成像技术，使用一种光可切换的荧光蛋白来评估时钟蛋白运动和周转的特征，这将适用于非植物的昼夜节律系统。我们还在利用小RNA处理的某些植物特有的优势来解决生物钟的其他转录后控制机制。综上所述，我们的计划将探索应该广泛适用于所有真核系统的昼夜节律控制机制。

 DESCRIPTION (provided by applicant): Circadian rhythms are nearly ubiquitous endogenous timing systems that help coordinate the myriad physiological, metabolic and developmental processes that occur continuously in each organism at all times of the day. This circadian clock is comprised at the molecular level of interlocked and autoregulatory feedback loops that are built from complex interactions that are constantly changing in relation to each throughout the 24 hour cycle. The long term goal of this project is to understand the functional relationships among the post- transcriptional processes that keep the circadian oscillator running. We are using genetic, genomic, biochemical and cell biological tools and strategies of the model plant Arabidopsis to identify the molecules and mechanisms that regulate the transport of important proteins and mRNA between the cytosol and nucleus. We are focused in part on how a range of post-translational modifications of clock proteins affect both their positional and temporal intracellular localization. Gatekeeping features of the intracellular environment will also be addressed, both on a genomic scale and at the level of a single molecular species. We are applying for the first time in circadian studies single cell imaging techniques using a photo switchable fluorescent protein to assess features of clock protein movement and turnover that will be applicable to non-plant circadian systems. We are also exploiting certain plant-specific advantages of small RNA processing to address other post- transcriptional control mechanisms of the circadian clock. Taken together our program will probe mechanisms of circadian control that should be broadly applicable across all eukaryotic systems.