Inter- and intracellular mechanisms of circadian regulation

项目摘要 昼夜节律几乎是无处不在的内源性计时系统，有助于协调无数的 生理、代谢和发育过程，在每个生物体中持续发生， 白天这种生物钟在分子水平上由互锁和自动调节反馈组成 这些循环是由复杂的相互作用建立起来的，这些相互作用在整个24小时内不断变化， 小时循环。本项目的长期目标是了解内部和外部之间的功能关系。 细胞内的过程，保持昼夜节律振荡器运行和协调整个植物。我们 利用模式植物拟南芥的遗传、基因组、生物化学和细胞生物学工具和策略， 确定调节细胞质和细胞外基质之间的时钟蛋白质转运的分子和机制， 原子核我们的部分重点是如何翻译后修饰的时钟蛋白影响他们的 位置和时间的细胞内定位。细胞内环境的守门功能，如 核孔（NP），也解决了，使用选择NP突变体，并在一个单一的分子水平 物种我们首次将单细胞成像技术应用于昼夜节律研究， 光开关荧光蛋白，以评估时钟蛋白的运动和营业额的特点， 适用于非植物昼夜节律系统。将探索从芽到根的长距离昼夜节律信号 使用选择的光感受器、激酶和葡萄糖信号突变体以及异常分生组织突变体。 无偏见的突变体筛选，以确定控制时钟蛋白水平的蛋白水解因子，将有助于理解 这些因素的精确时间定相的重要性。我们也在利用某些植物特有的 小RNA加工解决昼夜节律的其他转录后控制机制的优势 时钟总之，我们的计划将探索昼夜节律控制的机制，应该广泛地 适用于所有真核生物系统。

Project Summary 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 inter- and intracellular processes that keep the circadian oscillator running and coordinated across the plant. 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 clock proteins between the cytosol and nucleus. We are focused in part on how post-translational modifications of clock proteins affect both their positional and temporal intracellular localization. Gatekeeping features of the intracellular environment, such as the nuclear pore (NP), are also addressed, using select NP mutants, 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 photoswitchable fluorescent protein to assess features of clock protein movement and turnover that will be applicable to non-plant circadian systems. Long-distance circadian signaling from shoot to root will be explored using select photoreceptor, kinase and glucose-signaling mutants as well as aberrant meristem mutants. Unbiased mutant screens to identify proteolytic factors controlling clock protein levels will help understand the importance of precise time-of-day phasing of these factors. 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.