Molecular analysis of circadian regulation in Arabidopsis

描述（由申请人提供）：昼夜节律为生物体提供了适应性优势，通过确保在一天中最适当的时间发生不同的生理过程来增强个体的健康和适应性。这项提议的长期目标是了解真核细胞昼夜节律的分子基础。我们在之前的研究中已经确定了生物钟的关键调节因子，现在将使用基因组、生化、遗传和数学建模方法来适当地将这些蛋白质置于昼夜节律系统中。我们将在拟南芥（Arabidopsis thaliana）中进行研究，拟南芥是一种模式植物，由于其紧凑的基因组，广泛的遗传和基因组资源，以及耐受染色质调控途径突变的能力，这种突变对其他复杂的真核生物是致命的，因此非常适合这些实验。我们将首先使用基因组学、生物化学和遗传学方法来表征一种在真核生物中保守的蛋白质（但未知的生物化学功能）在染色质调控中的作用。我们期望这项工作将产生对各种真核生物中染色质组织和基因表达机制的见解。接下来，我们将使用遗传和生化技术来研究一系列相关转录因子在昼夜节律工作中的作用

DESCRIPTION (provided by applicant): Circadian rhythms provide organisms with an adaptive advantage, enhancing the health and fitness of individuals by ensuring that diverse physiological processes occur at the most appropriate times of day. The long-term objective of this proposal is to understand the molecular basis of circadian rhythms in eukaryotic cells. We have identified key regulators of the circadian clock in our previous studies, and will now use genomic, biochemical, genetic, and mathematical modeling approaches to appropriately place these proteins in the circadian system. We will conduct our studies in Arabidopsis thaliana, a model plant that is uniquely well-suited for these experiments due to its compact genome, extensive genetic and genomic resources, and ability to tolerate mutations in chromatin regulatory pathways that are lethal to other complex eukaryotes. We will first use genomic, biochemical, and genetic approaches to characterize the role of a protein conserved across eukaryotes (but of unknown biochemical function) in the regulation of chromatin. We anticipate this work will generate insights into mechanisms governing chromatin organization and thus gene expression in diverse eukaryotes. Next, we will use genetic and biochemical techniques to investigate the roles of a family of related transcription factors in the workings of the circadian oscillator. In the process, we will test predictions made by a mathematical model, evaluating how well this model describes the regulatory relationships that drive the clock. Finally, we will modify an existing competitive chromatin immunoprecipitation protocol to investigate how the binding dynamics of antagonistic transcription factors to chromatin shape the dynamic regulation of gene expression in vivo. These experiments will reveal general principles governing the temporal regulation of gene expression and thus will be applicable to many organisms and processes. Our exploration of shared mechanisms that control circadian clock function in diverse organisms will increase our understanding of how clocks function in humans and shed light on how they promote human health and welfare.