Investigating Circadian Mechanisms of Cellular Resilience: Rhythmic Condensates, Disorder, and Stress

项目摘要(摘要) 使细胞生理与地球的明/暗周期同步的内源生物钟影响 生理学的方方面面--从分子到细胞再到行为。昼夜节律系统在以下方面起着不可或缺的作用 促进细胞在面对环境或内部扰动时的弹性。昼夜节律的扰乱 与心血管疾病、肥胖、肺部疾病和神经精神障碍有关，强调 细胞时钟机制基础知识对临床医学的重要性。而当 昼夜节律计时的分子基础已经被精确定义，时钟如何对 维持细胞内稳态的环境在很大程度上仍是未知的。 我们将测试这样的假设，即核心昼夜节律时钟蛋白质时钟是压力传感器， 通过其内在无序区域中的结构元素将环境信息传输到 昼夜计时机制和应激反应机制。我们已经发现，RNA 伴侣DDX3X关键地调节时钟对环境刺激(如温度)的敏感性 对昼夜节律计时和细胞弹性都有很大的影响。我们将决定时钟如何 在机械上与细胞应力机制结合，包括热休克反应。超越它的 作为压力传感器，我们将研究昼夜节律系统和时钟是如何自适应地组织 蛋白质组的生化状态，塑造参与其中的生物通路的昼夜节律组装 动态平衡。我们将在动物身上测试这些细胞数据，方法是测量基因和行为模型 昼夜节律紊乱和睡眠不足重新编程了蛋白质组装的节律性。最后，我们会 将这些发现应用于人类外周血样本，在这些样本中，我们首次发现 蛋白质合成的节律。这一提议因其多尺度和跨学科的方法而得到加强。 它利用国际生物研究所在时间生物学、细胞生物学和生物化学方面的专业知识，与 人类昼夜节律生物学(Klerman)、蛋白质组学和磷蛋白质组学(ASARA)、活细胞和 超分辨率成像(Chen)和成像和分析开发(Barrett)。 我们的假设是，昼夜节律弹性的分子机制及其在应激中的失败 连接整合的细胞应激反应和昼夜节律的不适应反馈回路 错位。决定生物钟监督、感知和响应的机制 环境刺激是将昼夜节律紊乱与疾病机制联系起来的一个关键挑战。我的临床 作为一名接受过睡眠医学培训的儿科神经科医生，背景和经验支持并告知我 对睡眠和昼夜节律紊乱的研究兴趣。我们预计，这一假设的成功检验 将为缓解昼夜节律之间的二价联系提供新的和药理上可行的靶点 错位以及与之相关的许多人类疾病。 好了！ 好了！

PROJECT SUMMARY (ABSTRACT) The endogenous circadian clock that synchronizes cellular physiology with the earth's light/dark cycle affects all aspects of physiology – from molecular to cellular to behavioral. The circadian system has an integral role in promoting cellular resilience in the face of environmental or internal perturbation. Circadian disruption has been linked with cardiovascular disease, obesity, pulmonary disease, and neuropsychiatric disorders, highlighting the importance of fundamental knowledge of cellular clock mechanisms for clinical medicine. While the molecular basis for circadian timekeeping has been exquisitely defined, how the clock responds to the environment to maintain cellular homeostasis remains mostly unknown. We will test the hypothesis that the core circadian clock protein CLOCK is a stress sensor that transmits environmental information through structural elements in its intrinsically disordered region to both the circadian timekeeping mechanism and the stress-response machinery. We have discovered that the RNA chaperone DDX3X critically regulates the sensitivity of CLOCK to environmental stimuli such as temperature and has potent effects on both circadian timekeeping and cellular resilience. We will determine how CLOCK mechanistically integrates with the cellular stress machinery, including the heat shock response. Beyond its role as a stress sensor, we will investigate how the circadian system and CLOCK adaptively organize the biochemical state of the proteome, sculpting the circadian assembly of biological pathways involved in homeostasis. We will test these cellular data in animals by measuring how genetic and behavioral models of circadian disruption and sleep deprivation re-program the rhythmicity of protein assemblies. Finally, we will apply these discoveries to human peripheral blood samples in which we have, for the first time, identified rhythms of protein synthesis. This proposal is strengthened by its multi-scaled and interdisciplinary approaches that harness the expertise of the PI in chronobiology, cell biology, and biochemistry in collaboration with experts in human circadian biology (Klerman), proteomics and phosphoproteomics (Asara), live cell and super-resolution imaging (Chen), and imaging and assay development (Barrett). Our hypothesis is that the molecular mechanisms for circadian resilience and their failure during stress underlie a maladaptive feedback loop that connects integrated cellular stress responses with circadian misalignment. Determining the mechanisms by which the circadian clock supervises, senses, and responds to environmental stimuli is a crucial challenge for linking circadian disruption to disease mechanisms. My clinical background and experience as a pediatric neurologist trained in sleep medicine supports and informs my research interest in sleep and circadian disorders. We anticipate that the successful testing of this hypothesis will offer novel and pharmacologically actionable targets for mitigating the bivalent link between circadian misalignment and the many human disorders associated with it. ! !