Biological functions and post-transcriptional regulation of microRNAs

microRNA的生物学功能和转录后调控

• 批准号: 10008705
• 负责人: Katherine McJunkin
• 金额: $ 111.45万
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10008705
• 关键词: Address; Animal Model; Animals; Behavior; Biochemical; Biogenesis; Biological; Biological Process; Biology; CRISPR/Cas technology; Caenorhabditis elegans; Cell Lineage; Cellular biology; Complex; Development; Disease; Embryo; Embryonic Development; Equilibrium; Exhibits; Family; Gene Expression; Gene Expression Regulation; Genetic; Malignant Neoplasms; Mediating; Messenger RNA; MicroRNAs; Molecular; Mutagenesis; Mutation; Organism; Pathway interactions; Phenotype; Physiological Processes; Plants; Play; Post-Transcriptional Regulation; Proteins; RNA interference screen; Regulation; Research; Role; Techniques; Tissue Differentiation; Untranslated RNA; deep sequencing; forward genetics; genome editing; insight; mutant; next generation sequencing; programs; tool

MiRNAs are small noncoding RNAs that are loaded into Argonaute proteins to form the core of the miRNA-Induced Silencing Complex (miRISC). MiRNAs guide miRISC to complementary target mRNAs to silence their expression. Mutations in miRNA loci disrupt gene expression programs, and thus can contribute to the development of various diseases, including cancer. Consequently, understanding both the functions of miRNAs in normal development and the molecular mechanisms that regulate miRNAs are biological questions of critical importance. Understanding the biological functions of miRNAs during embryogenesis While the functions of miRNAs in differentiated tissues are well-studied in C. elegans and other organisms, the embryonic functions of only a few animal miRNAs are understood. Moreover, how miRNAs contribute to the largely post-transcriptional control of gene expression prior to the maternal-to-zygotic transition (MZT) is completely unknown. C. elegans is an excellent model organism in which to study embryonic development due to its well-defined stereotypic cell lineage and powerful genetic tools. Our group is using use C. elegans to elucidate the functions of miRNAs in embryogenesis, first focusing on the miRNA families that are required for embryogenesis. To dissect the biological pathways controlled by these miRNAs, our group is conducting forward (mutagenesis) and reverse (RNAi) screens for suppressors of microRNA family mutant phenotypes. Understanding the biological networks impacted by the embryonically-expressed microRNA families will yield important insights into how gene expression is controlled to coordinate embryogenesis. Defining the molecular mechanisms of miRNA and Argonaute turnover The balance of the rates of miRNA biogenesis and decay control miRNA abundance, and thus gene expression programs. Previous research has carefully elucidated mechanisms of miRNA biogenesis. However, we know very little about how miRNAs and miRISC are turned over either constitutively or in a regulated manner. This is a major gap in our understanding of miRNA regulation, and thus the regulation of gene expression. During this fiscal period, we have focused on using deep sequencing to elucidate the role of untemplated 3 additions in global microRNA turnover.

miRNA 是小的非编码 RNA，被加载到 Argonaute 蛋白中，形成 miRNA 诱导沉默复合物 (miRISC) 的核心。 MiRNA 引导 miRISC 找到互补的靶 mRNA，以沉默其表达。 miRNA 位点的突变会破坏基因表达程序，从而导致包括癌症在内的各种疾病的发生。因此，了解 miRNA 在正常发育中的功能以及调节 miRNA 的分子机制是至关重要的生物学问题。 了解胚胎发生过程中 miRNA 的生物学功能 虽然 miRNA 在分化组织中的功能在秀丽隐杆线虫和其他生物体中得到了充分研究，但只有少数动物 miRNA 的胚胎功能被了解。此外，在母体向合子转变（MZT）之前，miRNA 如何在很大程度上促进基因表达的转录后控制仍是完全未知的。秀丽隐杆线虫因其明确的定型细胞谱系和强大的遗传工具而成为研究胚胎发育的优秀模型生物。我们的小组正在使用线虫来阐明 miRNA 在胚胎发生中的功能，首先关注胚胎发生所需的 miRNA 家族。 为了剖析这些 miRNA 控制的生物途径，我们的小组正在对 microRNA 家族突变表型的抑制因子进行正向（诱变）和反向（RNAi）筛选。了解受胚胎表达的 microRNA 家族影响的生物网络将为了解如何控制基因表达以协调胚胎发生提供重要见解。 定义 miRNA 和 Argonaute 更新的分子机制 miRNA 生物发生和衰变速率的平衡控制 miRNA 丰度，从而控制基因表达程序。先前的研究已经仔细阐明了 miRNA 生物发生的机制。然而，我们对 miRNA 和 miRISC 如何组成性或以调控方式翻转知之甚少。这是我们对 miRNA 调控以及基因表达调控理解的一个重大差距。在本财年期间，我们重点关注使用深度测序来阐明非模板 3 添加在全球 microRNA 周转中的作用。