Molecular, cellular and physiological mechanisms of the mammalian circadian clock

项目摘要/摘要 生物钟调节生理和行为的许多方面。这些节奏是 由下丘脑视交叉上核(SCN)的主时钟协调。这 核心时钟由转录/翻译负反馈环组成，其中 转录激活因子BMAL1/CLOCK调节其自身抑制因子的表达 PER和CORT蛋白。这一压抑步骤是至关重要的，因为没有它，就没有节奏。钥匙 抑制过程中的步骤是PER/CREY蛋白复合体的协调易位 从细胞质到细胞核。最近，我们发现同一个NRON复合体 调节NFAT通路的转位，也调节PER/CRY的转位 复杂的昼夜节律时钟功能。NFAT途径调节发育，但也是先天的 以及外周和中枢神经系统的适应性免疫。这个NRON复合体是 由信号分子组成，例如CSNK1e、GSK3B和DYRK1(已知的时钟蛋白)，但是 还有支架(IQGAP1，ncRNA NRON)，蛋白质分解(PSMD11，CUL4B，UREB1)，以及 核易位(KPNB1、CSE1L、TNPO1)。在人类细胞中使用遗传学 果蝇，我们已经证明了这些成分中的大多数都改变了周期长度，或者是 时钟功能齐全(KPNB1、PSMD11)。此外，药理上的微扰 NFAT通路改变SCN的生理和昼夜节律功能。在这里，我们寻求更好地 通过了解其生化和细胞生物学来理解这一关键的抑制步骤 机制，研究SCN中两条通路之间的串扰，并生成一套 用遗传模型来描述这些基因在调节SCN时钟和 睡眠/唤醒周期。这项工作将在NFAT调节的细胞之间提供第一个广泛的联系 和生理过程，包括大脑中的免疫力和核心时钟功能 管理行为和相关的生理。

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.