Molecular, cellular and physiological mechanisms of the mammalian circadian clock

项目总结/摘要 生物钟调节生理和行为的许多方面。这些节奏是 由下丘脑的视交叉上核（SCN）中的主时钟协调。这 核心时钟由转录/翻译负反馈回路组成，其中 转录激活因子BMAL 1/CLOCK调节其自身阻遏物的表达， PER和CRY蛋白。这个压抑的步骤是至关重要的，因为没有它，就没有节奏。关键 阻遏过程中的一个步骤是PER/CRY蛋白复合物的协调易位 从细胞质到细胞核。最近，我们发现同样的NRON复合物， 调节NFAT途径的易位，也调节PER/CRY的易位， 复杂的生物钟功能。NFAT通路调节发育，但也调节先天性 以及外周和中枢神经系统的适应性免疫。这个NRON综合体是 包括信号分子，例如CSNK 1 e、GSK 3B和DYRK 1（已知的时钟激酶），但 还有支架（IQGAP 1，ncRNA NRON），蛋白水解（PSMD 11，CUL 4 B，UREB 1），和 核易位（KPNB 1、CSE 1 L、TNPO 1）。利用人类细胞和 果蝇，我们已经表明，这些成分中的大多数改变周期长度或需要 时钟功能（KPNB 1，PSMD 11）。此外，药物干扰的作用， NFAT通路改变SCN生理和昼夜节律功能。在这里，我们寻求更好的 通过了解它的生物化学和细胞生物学， 机制，研究SCN中两条通路之间的串扰，并生成一套 遗传模型来表征这些基因在调节SCN时钟和细胞周期中的作用。 睡眠/唤醒周期。这项工作将提供第一个广泛的联系，NFAT调节的细胞， 和生理过程，包括大脑中的免疫力和核心时钟功能， 支配着行为和相关的生理学。

PROJECT SUMMARY/ABSTRACT The circadian clock regulates many aspects of physiology and behavior. These rhythms are coordinated by the master clock in the suprachiasmatic nuclei (SCN) of the hypothalamus. This core clock is composed of a transcriptional/translational negative feedback loop, where transcriptional activators BMAL1/CLOCK regulate the expression of their own repressors, the PER and CRY proteins. This repression step is critical, as without it, there's no rhythm. The key step in the repression process is coordinated translocation of the PER/CRY protein complex from the cytoplasm to the nucleus. Recently, we've found that the same NRON complex that regulates translocation of the NFAT pathway, also regulates the translocation of the PER/CRY complex and circadian clock function. The NFAT pathway regulates development but also innate and adaptive immunity in the periphery and the central nervous system. This NRON complex is comprised of signaling molecules, e.g. CSNK1e, GSK3B, and DYRK1 (known clock kinases), but also scaffolding (IQGAP1, the ncRNA NRON), proteolysis (PSMD11, CUL4B, UREB1), and nuclear translocation (KPNB1, CSE1L, TNPO1). Using genetics in human cells and in Drosophila, we've shown that most of these components alter period length or are required for clock function altogether (KPNB1, PSMD11). Further, pharmacological perturbation of the NFAT pathway alters SCN physiology and circadian function. Here, we seek to better understand this key repression step by understanding its biochemical and cell biological mechanisms, study the cross talk between the two pathways in the SCN, and generate a suite of genetic models to characterize the role of these genes in modulating the SCN clock and the sleep/wake cycle. This work will provide the first broad linkage between NFAT-regulated cell and physiological processes including immunity in the brain and core clock function that governs behavior and associated physiologies.