Dissecting how protein degradation couples the circadian clock to downstream processes

对于大多数活着的有机体来说，特定的生物过程必须在一天中的特定时间发生。例如，在植物中，光合作用，即将光能和二氧化碳转化为糖的过程，必须计时到白天。许多额外的重要过程是由一种控制日常计时的机制解析出来的，这种机制被称为生物钟。关于组成植物生物钟的基因和蛋白质，人们知道很多；然而，生物钟实际上如何控制特定的生物过程，如光合作用，还不清楚。这项提议概述了一些实验，这些实验将发现生物钟和其中一些定时生物过程之间的联系。了解这些联系将有助于我们培育出产生更多能量并能抵抗环境变化的农作物，例如由全球气候变化引起的变化。关于生物钟和下游生物过程之间的转录联系，人们知道得很多，但建立起来的非转录联系要少得多。一个例子是季节性开花的符合模型，它例证了一种基于蛋白质降解的机制，将时钟与季节性开花联系起来。在这个系统中，一个昼夜节律的时钟控制的F-box蛋白对开花的关键调控因子的降解进行计时。除了这个例子，还有另外32个昼夜节律时钟控制的F-box蛋白，它们的生物学功能很少或根本不知道。为了充分了解生物钟和下游过程之间基于蛋白质降解的耦合，必须了解这些F-box蛋白的功能。在这项建议中，定义了一种策略来逆转32个昼夜节律时钟控制的F-box蛋白的功能，以研究它们的功能。这项提议中的实验的完成将为研究生物钟和下游生物过程之间基于蛋白质降解的耦合机制提供关键的工具集和数据集。此外，拟议的研究将促进各级科学发现的培训和科学互动。1)本科生、研究生、博士后研究人员和访问学者将在实验室接受植物遗传学、分子生物学和生物化学方面的培训；2)每月一次的植物展示？将继续把耶鲁大学的植物科学教师、学生和人员与纽黑文的高中生和中学生聚集在一起，培养他们对植物生物学和年轻科学家进行STEM教育的兴趣；3)拟议的工作旨在直接应用于作物物种，将成为引入环境可塑性以应对全球环境变化的强大工具；4)将通过社交媒体向普通公众传播工作。该实验室维护着一个推特账户(@GendronLab)，植物展示的演示文稿以播客的形式发布，可以免费下载(http://greencafe.yale.edu).这是为了加强对科学的宣传，重点是植物科学。

For most living organisms, specific biological processes must happen at specific times of day. For example, in plants, photosynthesis, the process that converts light energy and carbon dioxide into sugar, must be timed to daylight hours. Many additional important processes are parsed out by a mechanism that controls daily timing called the circadian clock. A lot is known about genes and proteins that make up the circadian clock in plants; however how the circadian clock actually controls particular biological processes such as photosynthesis is not known. This proposal outlines experiments that will discover connections between the circadian clock and some of these timed biological processes. Understanding these connections will help us make crop plants that produce more energy and are resistant to changes in the environment, such as those caused by global climate change. Much is known about the transcriptional connections between the circadian clock and downstream biological processes, but far fewer non-transcriptional connections have been made. One example is the coincidence model for seasonal flowering which exemplifies a protein degradation-based mechanism for coupling the clock to seasonal flowering. In this system a circadian clock-controlled F-box protein times the degradation of a key regulator of flowering. Beyond this example, there are 32 additional circadian clock-controlled F-box proteins with little or no known biological function. To fully understand the protein degradation-based couplings between the circadian clock and downstream processes, the functions of these F-box proteins must be understood. In this proposal a strategy is defined for inverting the function of the 32 circadian clock-controlled F-box proteins to study their functions. The completion of the experiments in this proposal will provide a critical toolset and dataset to investigate protein degradation-based coupling mechanisms between the circadian clock and downstream biological processes. In addition, the proposed research will promote training and scientific interaction at various levels of scientific discovery. 1) Undergraduates, graduate students, post-doctoral researchers, and visiting scholars will be trained in plant genetics, molecular biology, and biochemistry in the laboratory; 2) A monthly plant ?showcase? will continue to bring together the plant science faculty, students, and personnel at Yale with New Haven high school and middle school students to foster interest in plant biology and STEM education with young scientists; 3) The proposed work is intended for direct application to crop species and will be a powerful tool to introduce environmental plasticity in order to respond to global environment changes; and 4) Dissemination of the work to the general public will be achieved using social media. The lab maintains a Twitter account (@GendronLab) and the presentations of the plant showcase are published as podcasts that are freely downloadable (http://greencafe.yale.edu). This is intended to increase advocacy for science with a focus on plant science.