Small Regulatory RNA Functions In The Nucleus

细胞核中的小调控 RNA 功能

• 批准号: 8791697
• 负责人: Scott G Kennedy
• 金额: $ 38.77万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8791697
• 关键词: Address; Animal Model; Animals; Antiviral Agents; Base Pairing; Beginning of Life; Binding; Biological Process; Biology; Caenorhabditis elegans; Cell Nucleus; Cell physiology; Cells; Chromatin; DNA; DNA Modification Process; DNA Sequence; Data; Deposition; Development; Epigenetic Process; Eukaryota; Eukaryotic Cell; Gene Expression; Gene Expression Regulation; Gene Silencing; Generations; Genes; Genetic; Genetic Transcription; Genome; Germ Cells; Goals; Health; Histones; Human; Immunity; Inherited; Lead; Mammalian Cell; Mammals; Mediating; Modification; Molecular; Nature; Nuclear; Nuclear RNA; Parents; Pathway interactions; Phase; Phenotype; Play; Polymerase; Process; Proteins; RNA; RNA Interference; RNA Interference Pathway; RNA Polymerase II; RNA Processing; Recruitment Activity; Regulator Genes; Reproduction; Research; Role; Signal Transduction; Small Nuclear RNA; Small RNA; Specificity; System; Transcript; Translations; Untranslated RNA; Work; X Inactivation; chromatin modification; design; fascinate; genetic approach; genetic information; human disease; imprint; insight; interest; mRNA Precursor; mRNA Stability; mutant; offspring; programs; research study; tool; tumorigenesis

DESCRIPTION (provided by applicant): Small regulatory RNAs regulate gene expression in most eukaryotes. By regulating gene expression, small regulatory RNAs, play key roles in many biological processes that include development, genome defense, oncogenesis, and antiviral immunity. Small regulatory RNAs act by seeking out and binding homologous (target) RNAs in cells. By recruiting accessory proteins to target RNAs, small RNAs are able to control gene expression at many levels that include; translation, mRNA stability, and transcription. The mechanistic underpinnings of small RNA biology are widely conserved in most eukaryotes. In particular, small RNAs play an important role in regulating gene expression within most eukaryote nuclei. My lab has established systems that are allowing us to study how and why small RNAs regulate genes in animal nuclei. We are using the model organism C. elegans to understand how small RNAs regulate gene expression in animal nuclei. We are using C. elegans to address this question because of the excellent genetic tools that are available, and because of the robust and facile nature of conducting RNAi experiments in this system. Using genetic approaches in C. elegans, we have identified a molecular pathway that uses small RNAs to recognize and mark nascent transcripts (and the genes that encode these transcripts) for silencing. We have identified accessory proteins (termed the nuclear RNAi defective (NRDE) factors), which are recruited by small RNAs to nascent transcripts emanating from RNAP Polymerase II. Finally, we have shown that the association of the NRDE factors with RNA transcripts allows that NRDE factors to inhibit RNA Polymerase II during the elongation phase of transcription. Some of the NRDE factors that we have identified are conserved in mammals. In summary, our work is helping us understand how small RNAs regulate gene expression in animal nuclei, and may lead to insights into how small RNAs regulate gene expression in mammals. We are also interested in understanding why small RNAs regulate gene expression in animal nuclei. Small regulatory RNAs direct the covalent modification of DNA and histones proteins in most eukaryotic cells. These small RNA-mediated chromatin modifications are epigenetic in nature: they alter gene expression without changing the underlying in DNA sequence. We have shown that endogenous nuclear small RNAs, and the nuclear RNAi pathway, regulate the epigenetic landscape at ~1000 genes during the normal course of reproduction. In animals that lack the nuclear RNAi machinery, germ cells loose their immortal character. Thus, C. elegans uses endogenous small RNAs to regulate epigenetic "states" at many genes during the normal course of reproduction and this gene-silencing process is required to mediate important biological processes. Many other biological processes such as development, imprinting, X-chromosome inactivation, and paramutation are directed by epigenetic modifications on DNA and histones. Interestingly, non-coding RNAs also contribute to many, if not all, of these processes. Given the widespread connections that exist between small RNAs, non-coding RNAs, and epigenetic processes in eukaryotes, we believe that our research exploring how small non-coding RNAs regulate epigenetic landscapes in C. elegans may prove to be globally applicable to diverse epigenetic processes in animals. We do not yet understand 1) how the recruitment of NRDE factors to pre-mRNA inhibits RNAP II elongation to direct nuclear RNAi, 2) how RNAi-guided chromatin modifications contribute to nuclear RNAi in animals, 3) if/how nuclear RNAi is regulated, or 4) if the NRDE nuclear RNAi pathway is functionally conserved in mammals. Our proposed experiments are designed to answer these questions. .

描述（由申请人提供）：小的调节RNA调节大多数真核生物的基因表达。通过调节基因表达，小的调节性RNA，在许多生物学过程中起关键作用，包括发育，基因组防御，肿瘤发生和抗病毒免疫。小调节性RNA通过在细胞中寻找和结合同源（靶）RNA来起作用。通过募集辅助蛋白靶向RNA，小型RNA能够控制许多级别的基因表达：包括：翻译，mRNA稳定性和转录。在大多数真核生物中，小RNA生物学的机械基础被广泛保守。特别是，小RNA在调节大多数真核生物核中的基因表达中起重要作用。我的实验室已经建立了系统，使我们能够研究小RNA如何以及为什么调节动物核中的基因。 我们正在使用模型有机秀丽隐杆线虫来了解小的RNA如何调节动物核中的基因表达。我们正在使用秀丽隐杆线虫来解决这个问题，因为可以使用出色的遗传工具，并且由于该系统中进行RNAi实验的强大和便捷性质。使用秀丽隐杆线虫中的遗传方法，我们确定了一种分子途径，该途径使用小的RNA识别并标记了新生的转录本（以及编码这些转录本的基因）进行沉默。我们已经鉴定出辅助蛋白（称为核RNAi缺陷（NRDE）因子），这些因素是由小的RNA募集到从RNAP聚合酶II产生的新生转录本。最后，我们已经表明，NRDE因子与RNA转录物的关联允许NRDE因子在转录延长阶段抑制RNA聚合酶II。我们确定的一些NRDE因素在哺乳动物中是保守的。总而言之，我们的工作正在帮助我们了解小的RNA如何调节动物核中的基因表达，并可能导致对小RNA如何调节哺乳动物中基因表达的见解。 我们也有兴趣了解为什么小RNA调节动物核中的基因表达。小调节性RNA指导大多数真核细胞中DNA和组蛋白蛋白的共价修饰。这些小的RNA介导的染色质修饰本质上是表观遗传学的：它们改变了基因表达而不改变DNA序列中的潜在。我们已经表明，在正常生殖过程中，内源性核小RNA和核RNAi途径调节〜1000个基因的表观遗传景观。在缺乏核RNAi机械的动物中，生殖细胞松散了其不朽的特征。因此，秀丽隐杆线虫在正常生殖过程中使用内源性小RNA来调节许多基因的表观遗传“状态”，并且需要这种基因沉默过程来介导重要的生物学过程。许多其他生物学过程，例如发育，印迹，X染色体灭活和参数。有趣的是，非编码RNA也会为这些过程中的许多（即使不是全部）做出贡献。考虑到真核生物中小的RNA，非编码RNA和表观遗传过程之间存在的广泛连接，我们认为我们的研究探讨了小型非编码RNA如何调节秀丽隐杆菌中的表观遗传景观，可能证明是全球适用于动物中多样的表观遗传过程。 We do not yet understand 1) how the recruitment of NRDE factors to pre-mRNA inhibits RNAP II elongation to direct nuclear RNAi, 2) how RNAi-guided chromatin modifications contribute to nuclear RNAi in animals, 3) if/how nuclear RNAi is regulated, or 4) if the NRDE nuclear RNAi pathway is functionally conserved in mammals.我们提出的实验旨在回答这些问题。 。