Collaborative Research: Biochemical Basis of Cellular Circadian Behavior

通过建立节律行为的遗传基础，生物钟研究是神经科学中一个伟大的成功故事。分子钟由正负两部分组成，它们形成一个反馈回路，构成大脑节律的基础。然而，“整体大于部分之和”，我们还不知道少数几个组成部分是如何协调产生紧急的日常节奏的。因此，本研究旨在确定核心时钟蛋白的生化特性，使节律行为。为此，该团队开发了一种综合方法，将基于细胞的遗传学和连续监测昼夜节律行为与生物化学/生物物理方法相结合。这种方法将使他们能够研究时钟蛋白的功能，不仅在试管中孤立，而且在相互作用的细胞中的振荡行为的背景下。这项工作将揭示时钟的“齿轮和弹簧”如何相互作用并共同发挥作用，这些知识将增加我们对大脑如何保持时间以及蛋白质如何相互作用以调节复杂大脑功能的理解。PI和他的同事们将教授一门讲座/实验室课程，该课程使用“从数学到基因再到行为”的平台，并为研究生提供跨学科培训。该团队还将在当地社区教授真实的世界概念，了解昼夜节律对健康的影响，这与所有背景和年龄的人有关。这些更广泛的影响将加强国家的科学基础设施，提高人们的健康意识。遗传学研究已经确定了几个核心的时钟组成部分，形成了负反馈机制，这是昼夜节律行为的基础。已经确定，在核心反馈环中，BMAL 1和CLOCK是两个转录激活因子，而CRY是主要的抑制因子。然而，转录中的负反馈不一定保证以约24小时的周期性重复细胞过程。昼夜节律是由核心生物钟因子激活的一种新特性，但细胞昼夜节律振荡的生化基础还没有得到很好的理解。该研究小组最近的研究表明，BMAL 1和CLOCK的结构灵活的C末端在调节与其他时钟因子的动态相互作用以实现昼夜节律振荡方面发挥着重要作用。在拟议的研究中，该团队将采用一种综合方法，将基于细胞的遗传学和动力学生物发光测定与生物化学和生物物理方法相结合，研究它们的C末端如何利用动态相互作用来调节节律幅度和周期长度。以这种方式，在体外和细胞昼夜节律行为的背景下评估蛋白质功能。通过提供细胞昼夜节律行为的生化基础，这项研究将定义昼夜节律转录复合体的分子结构，推进目前对负反馈机制的理解，并进一步实现行为神经生物学的目标。在研究期间，PI和他的同事将为研究生提供跨学科的教育和培训，并向公众宣传昼夜节律对健康的重要影响。

Non-Technical Paragraph By establishing the genetic basis of rhythmic behavior, circadian clock research is a great success story in neuroscience. The molecular clock consists of positive and negative components that form a feedback loop that underlies brain rhythms. However, "the whole is greater than the sum of its parts," and we do not yet know how a handful of components coordinate to give rise to emergent daily rhythms. Therefore, this research aims to identify the biochemical properties of core clock proteins that enable rhythmic behavior. To do this, the team has developed an integrative approach that combines cell-based genetics and continuous monitoring of circadian behavior with biochemical/biophysical methods. This approach will allow them to study the function of clock proteins not only in test tubes in isolation, but also in the context of oscillatory behavior in interacting cells. This work will reveal how the "gears and springs" of the clock interact and function together, and this knowledge will increase our understanding of how the brain keeps time, as well as how proteins interact to regulate complex brain functions. The PI and his colleagues will teach a lecture/lab course that uses a "from math to genes to behavior" platform and provides cross-disciplinary training for graduate students. The team will also teach real world concepts in the local community about the health implications of circadian rhythms, which relates to people of all backgrounds and ages. These broader impacts will strengthen the nation's scientific infrastructure and improve people's health awareness. Technical Paragraph Genetic studies have identified several core clock components that form a negative feedback mechanism, which underlies circadian behavior. It is well established that, in the core feedback loop, BMAL1 and CLOCK are the two transcription activators and CRY serves as the chief repressor. However, negative feedback in transcription does not necessarily warrant recurring cellular processes with a ~24 hr periodicity. The circadian rhythm is an emergent property enabled by the core clock factors, but the biochemical basis of cellular circadian oscillation is not well understood. Recent studies from this research team show that the structurally flexible C-termini of BMAL1 and CLOCK play essential roles in regulating dynamic interactions with other clock factors to enable circadian oscillations. In the proposed research, the team will employ an integrated approach that combines cell-based genetics and kinetic bioluminescence assays with biochemical and biophysical methods to study how their C-termini use dynamic interactions to regulate rhythm amplitude and period length. In this way, protein function is assessed both in vitro and in the context of cellular circadian behavior. By providing a biochemical basis of cellular circadian behavior, this research will define the molecular architecture of the circadian transcription complex, advance current understanding of the negative feedback mechanism, and further the goals of behavioral neurobiology. During the research, the PI and his colleagues will provide cross-disciplinary education and training for graduate students and inform the general public about the important health implications of circadian rhythms.