Exploring the structural basis for 24-hour timekeeping in mammals

探索哺乳动物 24 小时计时的结构基础

• 批准号: 8897412
• 负责人: Carrie L Partch
• 金额: $ 28.32万
• 依托单位: UNIVERSITY OF CALIFORNIA SANTA CRUZ
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8897412
• 关键词: Address; Affect; Basic Science; Behavior; Binding; Binding Sites; Biochemical; Biochemical Process; Biochemistry; Biological Process; Biology; C-terminal; Cardiovascular Diseases; Cell Proliferation; Cells; Cellular biology; Chromatin; Circadian Rhythms; Complex; DNA; DNA Binding; Diabetes Mellitus; EP300 gene; Environment; Equilibrium; Exons; Foundations; Generations; Genetic Transcription; Genome; Goals; Health; Homeostasis; Hour; Human; Imides; In Vitro; Incidence; Knowledge; Lead; Malignant Neoplasms; Mammals; Mediating; Metabolic syndrome; Molecular; Molecular Mimicry; NMR Spectroscopy; Outcomes Research; Pathway interactions; Peptidylprolyl Isomerase; Physiology; Premature aging syndrome; Preventive; Protein Dynamics; Proteins; Recruitment Activity; Regulation; Research; Resolution; Role; Solutions; Structure; Techniques; Testing; Therapeutic; Time; Transactivation; Transcription Coactivator; Transcription Repressor/Corepressor; Transcriptional Activation Domain; Transcriptional Regulation; Translational Research; Work; base; cancer cell; circadian pacemaker; cis trans isomerization; conformer; fitness; flexibility; histone methyltransferase; human disease; in vivo; innovation; insight; novel therapeutics; programs; public health relevance; transcription factor

DESCRIPTION (provided by applicant): Mammals have an internal molecular clock that coordinates physiology into rhythms that coincide with the external solar day, providing enhanced evolutionary fitness by timing the peak activity of integrated biochemical processes. Loss of this internal 24-hour circadian clock leads to diabetes, metabolic syndrome, cancer, and premature aging by disrupting the temporal coordination of physiology with our behavior and the external environment. The long-term goal is to develop a deeper mechanistic understanding of how the molecular clock generates 24-hour timing in humans, in order to capitalize on this temporal regulation to develop new and innovative strategies to treat a broad spectrum of human diseases. The objective in this proposal is to identify the structural basis for transcriptional regulation by the primary circadian transcription factor, CLOCK:BMAL1, which controls expression of nearly 15% of the genome on a daily basis to drive circadian rhythms of physiology. Despite its critical importance in human physiology, very little is known about what governs the temporal switch from active to repressive CLOCK:BMAL1 complexes that create the intrinsic 24-hour period of the molecular clock. The central hypothesis is that CLOCK and BMAL1 transcriptional activation domains use intrinsic flexibility to regulate binding of activator and repressors to contribute to 24-hour timing of the molecular clock. Using nuclear magnetic resonance spectroscopy, quantitative biochemistry and cell-based studies, we will pursue two specific aims investigating 1) how a dynamic conformational switch in the BMAL1 activation domain regulates CLOCK:BMAL1 activity and 2) how competition for binding to the CLOCK activation domain regulates CLOCK:BMAL1 in normal clock function and in human cancer. Our innovative approach integrates diverse techniques from cell biology to solution NMR spectroscopy to generate biomedically relevant, atomic-level insight into clock function. The proposed research is significant, because it is expected to provide fundamentally new conceptual advances that address how CLOCK:BMAL1 works to generate 24-hour molecular rhythms and control global homeostasis. Ultimately, such knowledge has the potential to inform new strategies for basic and translational research into circadian control of human physiology.

描述（由申请人提供）：哺乳动物有一个内部分子钟，可以将生理学协调成与外部太阳日一致的节律，通过计时综合生化过程的峰值活动来增强进化适应性。失去这种内部 24 小时生物钟会破坏生理与我们的行为和外部环境的时间协调，从而导致糖尿病、代谢综合征、癌症和过早衰老。长期目标是更深入地了解分子钟如何在人类中产生 24 小时计时，以便利用这种时间调节来开发新的创新策略来治疗广泛的人类疾病。该提案的目的是确定主要昼夜节律转录因子 CLOCK:BMAL1 转录调节的结构基础，该因子每天控制近 15% 的基因组表达，以驱动生理昼夜节律。尽管 CLOCK:BMAL1 复合物在人类生理学中至关重要，但人们对是什么控制着 CLOCK:BMAL1 复合物从活跃到抑制的时间转换知之甚少，而 CLOCK:BMAL1 复合物创造了分子钟的内在 24 小时周期。中心假设是 CLOCK 和 BMAL1 转录激活域利用内在的灵活性来调节激活子和阻遏子的结合，从而有助于分子钟的 24 小时计时。利用核磁共振波谱、定量生物化学和基于细胞的研究，我们将追求两个具体目标，研究 1) BMAL1 激活域中的动态构象开关如何调节 CLOCK:BMAL1 活性；2) 与 CLOCK 激活域结合的竞争如何在正常时钟功能和人类癌症中调节 CLOCK:BMAL1。我们的创新方法集成了从细胞生物学到溶液核磁共振波谱的多种技术，以产生生物医学相关的、原子级的时钟功能洞察。拟议的研究意义重大，因为它有望提供全新的概念进展，解决 CLOCK:BMAL1 如何产生 24 小时分子节律并控制全局稳态。最终，这些知识有可能为人类生理学昼夜节律控制的基础和转化研究提供新策略。