The FRH DEXH box helicase: analysis of a core component of the Neurospora circadi

描述（由申请人提供）：昼夜节律是生物实体的生化，生理或行为过程中大约24小时的周期，从动物到蓝藻都存在。昼夜节律被定义为一个周期约为一天的周期，可以在没有时间线索的情况下持续存在，同时保留被时间线索重置的能力，并且不受这些线索之外的信号的影响。神经孢子菌时钟是研究得最好的昼夜节律系统之一，构成其核心成分的蛋白质包括频率（FRQ）、白领1 （WC-1）、白领2 （WC-2）和频率相互作用RNA解旋酶（FRH）。虽然前三个组成部分已经得到了很好的研究，但关于FRH在神经孢子虫时钟的功能中所起的作用仍然存在许多问题。这项工作的目的是确定FRH在神经孢子虫生物钟中的功能。为了研究这一机制，我将采用多方面的方法。在Specific Aim 1中，我将使用FRHR806H菌株识别对细胞生长和发育至关重要的FRH区域，并将它们与与生物钟功能相关的区域区分开来；在保持身体健康的同时，生物钟的节奏被打破的一种紧张状态。在具体目标2中，为了进一步了解FRH的功能和重要性，我将研究其他核心组件与FRH之间的相互作用，同时确定FRH中对每种相互作用重要的区域。在Specific Aim 3中，我将确定FRH的RNA靶点，并探索其作为mRNA相互作用蛋白的作用，这一功能是由其与DEAD box蛋白家族，特别是DSHCT家族的同源性所提示的。由于其与DEAD-box蛋白的相似性，因此可以合理地断言FRH可能促进时钟控制基因mrna与必要伴侣的相互作用。这将展示昼夜节律系统控制的一个全新水平。考虑到真菌和动物时钟之间的许多相似之处，特别是包括调控结构和组件的保护，了解一个涉及昼夜节律核心的新蛋白质家族的功能，拓宽了我们如何理解时钟机制的视野。确定这个新玩家的具体角色将梳理出另一个层次的意识，即对时钟的敏感性和反应。由于神经孢子虫时钟经常被用来理解人体时钟，这可以让我们更深入地了解我们的周期以及与之相关的所有含义，从生态学到人类疾病。

DESCRIPTION (provided by applicant): Circadian rhythms are a roughly 24-hour cycle in the biochemical, physiological or behavioral processes of living entities and are present from animals to cyanobacteria. A circadian rhythm is defined as a cycle that has a period of about a single day, can persist in the absence of time cues while retaining the ability to be reset by them, and is not affected by signals outside these cues. The proteins that constitute the core components of the Neurospora clock, one of the best-studied circadian systems, include Frequency (FRQ), White Collar 1 (WC-1), White Collar 2 (WC-2) and Frequency Interacting RNA Helicase (FRH). While the first three components are well studied, many questions remain about the role that FRH plays in the function of the Neurospora clock. The aim of this work is to identify the function of FRH in the Neurospora circadian clock. To investigate this mechanism, I will use a multi-facetted approach. In Specific Aim 1, I will identify the regions of FRH that are essential to cellular growth and development, and distinguish them from regions that are related to the function of the circadian clock using the FRHR806H strain; a strain in which the rhythmicity of the clock is knocked out while maintaining the health of the strain. In Specific Aim 2, to further understand the function and importance of FRH, I will look at the interactions between the other core components and FRH, while identifying the regions of FRH important for each interaction. In Specific Aim 3, I will determine the RNA targets of FRH and explore its role as an mRNA interacting protein, a function that is suggested by its homology to the DEAD box family of proteins, in particular the DSHCT family. Because of its similarity to DEAD-box proteins it is logical to assert that FRH may facilitate the interaction of clock controlled gene mRNAs with necessary partners. This would demonstrate an entirely new level of control in the circadian system. Given the many and strong similarities between fungal and animal clocks, specifically including the conservation of regulatory architecture and components, understanding the function of a new family of proteins involved at the core of the circadian rhythm broadens the horizons of how we understand the clock mechanism. Identifying the specific role of this new player will tease out yet another level of awareness as to the sensitivity and response of the clock. Since the Neurospora clock is often used to understand the human clock, this could give us greater insight into our cycle and all of the implications that are associated with it, from ecology to human disease. PUBLIC HEALTH RELEVANCE: Given the many and strong similarities between fungal and animal clocks, understanding the function of a new family of proteins involved at the core of the circadian rhythm broadens the horizons of how we understand the clock mechanism (1). The effectiveness of medical treatment, sleep disorders, psychiatric disorders, cardiovascular disease, and cancer have all been linked to the rhythm of the circadian clock (2-6). Since the Neurospora clock is often used to understand the human clock, this could give us greater insight into our cycle and all of the implications that are associated with it.