Diurnal and Circadian Regulation of Protein Synthesis

蛋白质合成是所有细胞和生物体的基本活动，其消耗相当大部分的能量和代谢物。特别是植物的生长通常受到氮供应的限制，因此通过氮肥促进。植物所需的大部分氮是蛋白质合成所需的。蛋白质合成的能量最终由阳光提供，而阳光只在白天可用。由于这些原因，重要的是要了解蛋白质合成是如何在昼夜周期调节。该项目将研究光刺激和植物内部的生物钟如何共同作用，以确保在白天和晚上都能产生适当的蛋白质。该项目还将阐述细胞信号响应机制，使植物能够感知营养信号并调节昼夜循环中的翻译。这项工作将在参考物种塔勒中进行，将对植物生长和发育产生影响，从而影响农业生产力，以及植物对其自然环境的适应。该项目旨在破译昼夜交替如何调节蛋白质合成（翻译）。最近来自这个实验室和其他实验室的全基因组研究表明，mRNA到蛋白质的翻译是由生物钟和光暗转换共同控制的。现在的阶段是解决两个主要的科学问题。首先，光能景观中的环境变化如何与生物钟相结合，以驱动翻译周期？这一目标将通过在一天中的时间和季节线索的背景下操纵光和营养环境，并通过测量mRNA核糖体加载的效率来实现。将使用基因特异性和全基因组测定来检查具有时钟缺陷以及光和营养感测缺陷的突变菌株的核糖体加载模式的改变。其次，保守的真核生物调控途径如何影响这种形式的翻译控制？现有的数据表明TOR激酶和GCN 2激酶途径参与了翻译控制，但这些细胞信号传导途径对蛋白质合成的确切贡献仍有待确定。 利用基因组学，分子遗传学和计算系统生物学方法，这项研究将启发植物生长的一个重要约束的基本基础，在昼夜环境中营养供应对蛋白质合成的调节。这项研究还将在一个迫切需要的领域发展科学劳动力。在其他培训活动中，该项目将招募来自东田纳西州的初中或高中教师，以创建课程计划和课程材料，使服务不足的学生熟悉科学规范，如基于模型的探究和计算思维。

Protein synthesis is a fundamental activity of all cells and organisms, which consumes a substantial fraction of energy and metabolites. The growth of plants, in particular, is usually limited by the supply of nitrogen, and hence boosted by nitrogen fertilization. Most of the nitrogen needed by plants is needed for protein synthesis. The energy for protein synthesis is ultimately provided by sunlight, which is only available during the day. For these reasons, it is important to understand how protein synthesis is regulated over the day night cycle. This project will investigate how light stimuli and the internal circadian clock of the plant work together to ensure that the appropriate proteins are produced both during the day and at night. The project will also elaborate the cellular signal response mechanisms that allow plants to sense nutrient signals and regulate translation over the diurnal cycle. This work, to be performed in the reference species thale cress, will have implications for plant growth and development, and thus agricultural productivity, as well as the adaptation of plants to their natural environment. This project seeks to decipher how the alternation of day and night regulates protein synthesis (translation). Recent genome-wide studies from this and other laboratories have revealed that the translation of mRNA into protein is controlled jointly by the circadian clock and by light-dark transitions. The stage is now set to tackle two major scientific questions. First, how are environmental changes in the light-energy landscape integrated with the circadian clock to drive cycles of translation? This objective will be pursued by manipulating the light and nutrient environment in the context of the time of day and seasonal cues and by measuring the efficiency of mRNA ribosome loading. Mutant strains with defects in the clock and in light and nutrient sensing will be examined for alterations in the patterns of ribosome loading using gene-specific and genome-wide assays. Second, how do conserved eukaryotic regulatory pathways affect this form of translational control? Existing data have implicated the TOR kinase and GCN2 kinase pathways in translational control, but the precise contribution of these cellular signaling pathways to protein synthesis remain to be defined. Using genomics, molecular genetics, and computational systems-biology approaches, this research will enlighten the fundamental basis of an important constraint to plant growth, the regulation of protein synthesis by nutrient supply in a diurnal environment. This research will also develop the scientific workforce in an area of critical need. Among other training activities, the project will recruit middle or high school teachers from East Tennessee to create lesson plans and curricular materials that will familiarize underserved students with norms of science such as model-based inquiry and computational thinking.