Mechanism and functions of small RNA pathways in Neurospora

脉孢菌小RNA途径的机制和功能

基本信息

批准号：
8642187
负责人：
YI LIU
金额：
$ 31.87万
依托单位：
UT SOUTHWESTERN MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-04-01 至 2017-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8642187
关键词：
Address Adoption Antiviral Agents Biochemical Biogenesis Biological Models Biological Process DNA DNA Damage DNA Methylation DNA biosynthesis Development Double-Stranded RNA Enzymes Eukaryota Eukaryotic Cell Exonuclease Experimental Designs Family Foundations Functional RNA Gene Expression Gene Expression Regulation Gene Silencing Generations Genes Genetic Genome Genomics Goals Human Individual Knowledge Lead Maintenance Mediating Messenger RNA MicroRNAs Molds Neurospora Neurospora crassa Nucleotides Organism Pathway interactions Pharmacologic Substance Plants Play Process Production Protein Family Proteins RNA RNA Interference RNA Interference Pathway RNA-Directed RNA Polymerase Recombinant DNA Ribonuclease III Ribonucleases Role Route Slice Small Interfering RNA Small RNA Structure System Technology Testing Transcript Transgenes Validation chromatin modification design fungus gene discovery gene function homologous recombination human DICER1 protein human disease member novel novel therapeutic intervention pri-miRNA public health relevance therapeutic development tool

项目摘要

DESCRIPTION (provided by applicant): 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, an organism that broadly employs gene silencing in regulation of gene expression, offers a unique and powerful system for understanding of RNAi pathways. We have previously established the biochemical mechanism for the dsRNA-induced activation of the RNAi pathway. By purifying the Argonaute QDE-2- associated sRNAs from Neurospora, we recently discovered three new types of sRNAs in this organism, including the DNA damage-induced qiRNA, first fungal miRNA-like sRNAs (milRNAs) and Dicer- independent small interfering RNAs (disiRNAs). Importantly, our studies demonstrated the existence of diverse sRNA biogenesis pathways in this organism, including Dicer-dependent and Dicer-independent mechanisms, and the roles of the Argonaute protein QDE-2 in sRNA biogenesis. In Specific Aim 1, we determine the mechanism of how DNA damage induces of qiRNA production and quelling. In Specific Aim 2, we will determine how different pri-milRNAs are processed into mature milRNAs by different pathways and will uncover the "design" principles that steer different milRNAs into different pathways. In Specific Aim 3, we will determine the biogenesis pathway and function of disiRNAs. Together, these studies address several fundamental questions in small RNA biogenesis and will expand our current knowledge of sRNA biogenesis pathways and sRNA function.

描述（由申请人提供）：RNA干扰（RNAi）是一种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，大小为 20-30 个核苷酸 (nt) 的小非编码 RNA (sRNA)，包括 microRNA (miRNA) 和各种小干扰 RNA (siRNA)，与 Argonaute 家族蛋白结合并引导其到达信使 RNA 靶标，导致多种生物过程中基因表达的沉默。丝状真菌粗糙脉孢菌是一种广泛利用基因沉默来调节基因表达的生物体，为理解 RNAi 途径提供了一个独特而强大的系统。我们之前已经建立了 dsRNA 诱导的 RNAi 途径激活的生化机制。通过从脉孢菌中纯化 Argonaute QDE-2 相关 sRNA，我们最近在该生物体中发现了三种新型 sRNA，包括 DNA 损伤诱导的 qiRNA、第一个真菌 miRNA 样 sRNA (milRNA) 和 Dicer 独立的小干扰 RNA。双siRNA）。重要的是，我们的研究证明了该生物体中存在多种 sRNA 生物发生途径，包括 Dicer 依赖性和 Dicer 独立机制，以及 Argonaute 蛋白 QDE-2 在 sRNA 生物发生中的作用。在具体目标 1 中，我们确定了 DNA 损伤如何诱导 qiRNA 产生和抑制的机制。在具体目标 2 中，我们将确定不同的 pri-milRNA 如何通过不同的途径加工成成熟的 milRNA，并将揭示引导不同的 milRNA 进入不同途径的“设计”原理。在具体目标 3 中，我们将确定 disiRNA 的生物发生途径和功能。这些研究共同解决了小 RNA 生物发生中的几个基本问题，并将扩展我们目前对 sRNA 生物发生途径和 sRNA 功能的了解。