Molecular mechanism of the piRNA biogenesis

piRNA生物发生的分子机制

基本信息

批准号：
9030803
负责人：
ALEXEI A. ARAVIN
金额：
$ 33.68万
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 2019-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9030803
关键词：
Address Aging Binding Biochemical Biogenesis Biomedical Research Cells Chromatin Chromatin Structure Code Complex DNA DNA Polymerase II DNA Transposable Elements Defect Disease Drosophila genus Drosophila melanogaster Epigenetic Process Eukaryotic Cell Failure Fertility Gene Cluster Gene Expression Regulation Generations Genetic Transcription Genome Genome Stability Genomic Segment Genomics Health In Vitro Investigation Lead Life Maintenance Maps Mediating Memory MicroRNAs Modeling Molecular Mus Nuclear Export Nucleotides Parasites Pathway interactions Play Positioning Attribute Process Property Protein Family Proteins RNA RNA Interference RNA Splicing RNA-Binding Proteins Recruitment Activity Regulation Reporter Repression Research Role Site Small Interfering RNA Somatic Cell Sorting - Cell Movement Specificity Staging Sterility Structure Techniques Testing Therapeutic Therapeutic Studies Transcript Transcription Initiation Transcription Process Transgenic Organisms Untranslated RNA Work base fly genome editing in vivo mRNA Precursor meetings member piRNA premature promoter protein complex public health relevance tool transcription termination transcriptome transcriptome sequencing transmission process tumor progression

项目摘要

DESCRIPTION (provided by applicant) 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. We discovered a new class of small non-coding RNAs, piwi-interacting RNAs (piRNAs), that 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 ncRNA transcripts, pre-piRNAs, that are further processed to mature piRNAs, which work as guides to recognize and repress transposon sequences. We showed that piRNA clusters have a unique chromatin signature that is essential for their expression and identified a protein complex that directly recognizes these chromatin marks. We further show that this complex is directly involved in transcription of pre-piRNA precursors and that transcription of clusters is unusual in a number of ways. Now we want to capitalize on our findings and understand how transcription and early steps of piRNA biogenesis are regulated. To meet these objectives we will dissect the molecular mechanism of piRNA biogenesis using Drosophila melanogaster. We will explore initiation and termination of pre-piRNA transcription using the combination of a new generation of transcriptome analysis tools as well as transgenic and genome editing approaches. We will also test the role of two complexes, Rhino/Cutoff and TREX, in transcription and processing of pre-piRNA. Our studies will help to advance our understanding of the mechanism of TE silencing, which is important for both fertility and for genomic stability in somatic cells. It will also provide the basis for futur use of the piRNA pathway as a tool in research and therapy. Importantly, the significance of the proposed research extends well beyond answering important questions in the non-coding RNA field. Our studies will provide clues to how co-transcriptional sorting of different types of RNAs into distinct processing pathways operates. It explores fundamental mechanisms that control transcription and early post- transcriptional processes.

描述（由申请人提供）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希望，但意外的方向。我们发现了一类新的非编码RNA PIWI相互作用RNA（PIRNA），它们与其蛋白质伴侣Piwi蛋白一起识别并沉默的内源性基因组寄生虫称为转溶性元素。转座子的沉默在生殖细胞中至关重要，而piRNA介导的表达的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簇产生长的NCRNA转录本，前PIRNA，进一步处理成成熟的PIRNA，它们是识别和反映转座子序列的指南。我们表明，piRNA簇具有独特的染色质特征，这对于它们的表达至关重要，并确定了直接识别这些染色质标记的蛋白质复合物。我们进一步表明，这种复合物直接参与了perna前体的转录，并且簇的转录在多种方面是不寻常的。现在，我们想利用我们的发现，并了解PIRNA生物发生的转录和早期步骤。为了满足这些目标，我们将使用果蝇Melanogaster剖析PIRNA生物发生的分子机制。我们将使用新一代转录组分析工具以及转基因和基因组编辑方法的组合来探讨piRNA转录的主动性和终止。我们还将测试犀牛/截止和Trex的两个复合物在perna的转录和处理中的作用。我们的研究将有助于提高我们对TE沉默机制的理解，这对于体育细胞中的生育和基因组稳定都很重要。它还将为未来使用PiRNA途径作为研究和治疗工具的基础。重要的是，拟议研究的重要性远远超出了在非编码RNA领域中回答重要问题的范围。我们的研究将为不同类型的RNA分类为不同的处理途径的共同分类提供线索。它探索了控制转录和转录后早期过程的基本机制。