Molecular Mechanism of the piRNA Biogenesis

piRNA 生物发生的分子机制

基本信息

批准号：
8274728
负责人：
ALEXEI A. ARAVIN
金额：
$ 28.82万
依托单位：
CALIFORNIA INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-06-06 至 2015-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8274728
关键词：
Affect Aging Animals Beryllium Biogenesis Biomedical Research Cell Line Cells Cellular Structures Chromatin Chromatin Structure Complementary DNA Cultured Cells Cytoplasmic Granules Cytoplasmic Structures DNA Transposable Elements Data Defect Drosophila genus Elements Epigenetic Process Eukaryotic Cell Failure Functional RNA Gene Expression Profile Gene Expression Regulation Genetic Transcription Genome Genomics Goals In Situ Hybridization Insecta Lead Light Maps Mediating Memory MicroRNAs Modeling Molecular Mus Parasites Pathway interactions Play Precursor RNA Process Promoter Regions Protein Family Proteins RNA RNA Interference RNA Polymerase II Regulation Regulatory Element Reporter Repression Research Rest Role Small Interfering RNA Small RNA Sterility Techniques Technology Testing Therapeutic Therapeutic Studies Transcript Transcription Initiation Site Work base chromatin immunoprecipitation chromatin protein knock-down meetings member mutant piRNA promoter protein complex research study tool tumor progression

项目摘要

DESCRIPTION (provided by applicant): Project title: Molecular mechanism of piRNA biogenesis. Project Summary: Non-coding RNAs have diverse functions in eukaryotic cells. Use of these non-coding RNAs in therapeutic approaches is a promising but rather unexplored direction in biomedical research. A few years ago, we discovered a new class of small non-coding RNAs, termed piwi-interacting RNAs (piRNAs), that are expressed in animal germlines. piRNAs, together with their protein partners, Piwi proteins, recognize and silence endogenous genomic parasites called transposable elements. The silencing of transposons is critical in germline cells and the failure of piRNA-mediated repression leads to sterility in both Drosophila and mice. The mechanism of biogenesis of piRNAs appears to be distinct from that of other classes of small non-coding RNAs, microRNA and siRNA. piRNAs are encoded in distinct genomic regions dubbed piRNA clusters that work as memory banks to store inactive copies of past transposon invaders. piRNA clusters produce long transcripts that are further processed to mature small RNA species. Our goal is to dissect piRNA biogenesis from their transcription to processing into mature piRNAs and to understand how these steps are regulated. We want to understand how transcripts that are destined for processing into piRNAs are selected and identify the enzymatic machinery responsible for processing. To meet these objectives we will dissect the molecular mechanism of piRNA biogenesis using D. melanogaster and insect cell lines. We will investigate the genomic and chromatin structure of piRNA clusters and map their promoter regions. These studies will identify regulatory elements necessary for piRNA expression and determine the role that chromatin plays in regulation of piRNA transcription. Next we will identify determinants in precursor transcripts that are required for piRNA biogenesis. We will determine if piRNA processing depends on distinct sequence elements inside the piRNA precursor transcripts. We will also search for a protein complex directly responsible for piRNA processing. Finally, we will study the intracellular localization of piRNA precursor transcripts and the role of nuage granules in piRNA biogenesis. Together, these experiments will comprehensively analyze all steps of piRNA biogenesis from transcription of precursor RNAs to processing into mature small RNAs. The failure of piRNA repression leads to sterility, and also might be important in aging and cancer progression. Thus, our findings will provide the basis for directing the piRNA pathway in order to make these non-coding RNAs useful tools in epigenetic research and in therapy.

描述（由申请人提供）：项目名称：PIRNA生物发生的分子机制。项目摘要：非编码RNA在真核细胞中具有不同的功能。在治疗方法中使用这些非编码RNA是生物医学研究中的一个有前途但尚未开发的方向。几年前，我们发现了一类新的非编码RNA，称为Piwi Interacting RNA（PIRNA），这些RNA在动物种系中表达。 PIRNA及其蛋白质伴侣PIWI蛋白识别并沉默的内源性基因组寄生虫称为转座元素。转座子的沉默在种系细胞中至关重要，而piRNA介导的抑制失败会导致果蝇和小鼠的不育。 PIRNA的生物发生机制似乎与其他类别的非编码RNA，microRNA和siRNA的生物发生不同。 PIRNA被编码在称为PIRNA簇的不同基因组区域中，这些区域可作为存储库存储过去转座子侵略者的不活跃副本。 PIRNA簇产生的长转录物进一步处理到成熟的小RNA物种。我们的目标是将PIRNA生物发生从转录到加工到成熟的PIRNA中，并了解如何调节这些步骤。我们想了解如何选择用于处理PIRNA的成绩单并确定负责处理的酶促机械。为了满足这些目标，我们将使用D. melanogaster和昆虫细胞系解剖PIRNA生物发生的分子机制。我们将研究piRNA簇的基因组和染色质结构，并绘制其启动子区域。这些研究将确定PIRNA表达所需的调节元素，并确定染色质在PIRNA转录调节中的作用。接下来，我们将确定PIRNA生物发生所需的前体转录本中的决定因素。我们将确定PIRNA处理是否取决于PiRNA前体转录本内部的不同序列元素。我们还将搜索直接负责PIRNA加工的蛋白质复合物。最后，我们将研究PIRNA前体转录本的细胞内定位以及Nuage颗粒在Pirna生物发生中的作用。总之，这些实验将全面分析PIRNA生物发生的所有步骤，从前体RNA转录到加工成成熟的小RNA。 piRNA抑制的失败会导致不育，并且在衰老和癌症进展中也可能很重要。因此，我们的发现将为指导PIRNA途径提供基础，以便在表观遗传学研究和治疗中使这些非编码RNA有用的工具。