Mechanisms of Circadian Clock and Gene Sliencing in Neurospora

脉孢菌生物钟和基因沉默的机制

• 批准号: 9903384
• 负责人: YI LIU
• 金额: $ 60.75万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-04 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9903384
• 关键词: Address; Animals; Award; Behavioral; Biochemical; Biogenesis; Biological Clocks; Biological Models; Biological Phenomena; Biological Process; Cell physiology; Chromatin Structure; Circadian Rhythms; DNA Damage; Development; Feedback; Future; Gene Expression; Gene Silencing; Genes; Genetic; Genetic Transcription; Goals; Grant; Human; Instruction; Knowledge; Lead; Mental Health; Mental disorders; Messenger RNA; MicroRNAs; Molds; Molecular; Molecular Conformation; Neurospora; Neurospora crassa; Nucleotides; Organism; Output; Pathway interactions; Pharmacologic Substance; Phosphorylation; Physiological; Physiological Processes; Physiology; Process; Production; Protein Family; RNA Interference; RNA Interference Pathway; Research; Research Personnel; Sleep Disorders; Small Interfering RNA; Small RNA; Structure; System; Technology; Untranslated RNA; Validation; circadian; circadian pacemaker; design; fungus; gene function; homologous recombination; human disease; insight; novel therapeutic intervention; public health relevance; temporal measurement; therapeutic development; tool

 DESCRIPTION (provided by applicant): This Maximizing Investigators' Research Award will be focused on the understanding of mechanisms of how fundamental biological phenomena: circadian clock and RNA interference. Circadian clocks control a wide variety of fundamental cellular, physiological, and behavioral processes in eukaryotic organisms. The molecular machinery that permits the measurement of time is referred to as the "circadian clock" and its output as circadian rhythms. Our long-term goal is to understand the molecular and biochemical mechanisms of eukaryotic circadian clocks. RNA interference (RNAi) is a post-transcriptional/transcriptional gene silencing mechanism conserved from fungi to humans. In RNAi pathways, small non-coding RNAs (sRNAs) with sizes ranging from 20-30 nucleotides (nt), including microRNAs (miRNAs) and various small interfering RNAs (siRNAs), associate with and guide Argonaute family proteins to messenger RNA targets, resulting in the silencing of gene expression in diverse biological processes. The filamentous fungus Neurospora crassa offers a powerful experimentally-accessible system for both circadian clock and RNAi mechanisms. Our previous studies have made fundamental contributions to both circadian and RNAi fields. For our future circadian clock research, we propose to focus on three different key aspects of the circadian oscillator mechanism. In Specific Aim 1, we will determine how phosphorylation of FRQ regulates its activity and its structural conformation. This study will help establish a biochemical mechanism critical for the circadian negative feedback process in Neurospora. In Specific Aim 2, we will determine the mechanism for how CATP regulates frq transcription by regulating the chromatin structure. In Specific Aim 3, we will determine the mechanism for how antisense transcription of qrf transcription regulates frq expression by transcriptional interference. Together, these objectives take advantage of a well-established model system to address three fundamental questions that are critical for our understanding of eukaryotic circadian clocks and will elucidate the genetic, biochemical, and molecular mechanism of the Neurospora clock. Because of the conservation between the Neurospora and animal clocks, our results will provide important insights into eukaryotic clock mechanisms. For our future RNAi and small RNA research, we will focus on the mechanisms of quelling, milRNA and dicer-independent small RNA pathways. In Specific Aim 4, we determine the mechanism of how DNA damage induces of qiRNA production and how qiRNAs promote homologous recombination. In Specific Aim 5, we will determine the milRNA production pathways and decipher the design principles of milRNAs. In Specific Aim 6, we will determine the biogenesis pathway and function of disiRNAs. Together, these studies address several fundamental questions in small RNA biogenesis and will significantly expand our current knowledge of sRNA biogenesis pathways and sRNA function.

 描述（由适用提供）：最大化研究人员的研究奖将集中在理解基本生物学现象的机制：昼夜节律时钟和RNA干扰。昼夜节律时钟控制真核生物中各种基本的细胞，物理和行为过程。允许时间测量的分子机制称为“昼夜节律”及其输出为昼夜节律。我们的长期目标是了解真核生物昼夜节律时钟的分子和生化机制。 RNA干扰（RNAI）是从真菌到人类保守的转录后/转录基因沉默机制。在RNAi途径中，小型非编码RNA（SRNA）的尺寸为20-30个核动脉底（NT），包括microRNA（miRNA）和各种小型干扰RNA（siRNAS），与Argonaute家族蛋白相关联，并指导Argonaute家族蛋白与Messenger RNA靶标，导致基因在多种基因表达中的沉默。丝状真菌Neurospora crassa为昼夜节律时钟和RNAi机制提供了强大的实验可访问系统。我们以前的研究为昼夜节律和RNAi领域做出了基本贡献。对于我们未来的昼夜节律研究，我们建议专注于昼夜节律振荡器机制的三个不同关键方面。在特定目标1中，我们将确定FRQ的磷酸化如何调节其活性及其结构构象。这项研究将有所帮助 建立一种对神经孢子中昼夜节律负面反馈过程至关重要的生化机制。在特定目标2中，我们将通过确定染色质结构来确定CATP如何调节FRQ转录的机制。在特定目标3中，我们将确定QRF转录反义转录如何通过转录干扰调节FRQ表达的机制。这些目标共同利用了一个良好的模型系统来解决三个基本问题，这对于我们对真核生物昼夜节律时钟至关重要，并将阐明神经孢子时钟的遗传，生化和分子机制。由于神经孢子和动物时钟之间的保护，我们的结果将为真核时钟机制提供重要的见解。对于我们未来的RNAi和小型RNA研究，我们将重点关注平流，MilRNA和DICER独立的小RNA途径的机制。在特定目标4中，我们确定了DNA损伤如何诱导QIRNA产生的机制以及QIRNA如何促进同源重组。在特定的目标5中，我们将确定MilRNA生产途径并破译Milrnas的设计原理。在特定的目标6中，我们将确定disirnas的生物发生途径和功能。总之，这些研究解决了小RNA生物发生中的几个基本问​​题，并将显着扩大我们当前对SRNA生物发生途径和SRNA功能的知识。