Novel functions for Sm-class RNAs in the regulation of gene expression

Sm 类 RNA 在基因表达调控中的新功能

• 批准号: 10330827
• 负责人: Demian Cazalla
• 金额: $ 38.38万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-16 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10330827
• 关键词: 3' Untranslated Regions; Base Pairing; Binding; Binding Sites; Biochemical; Biological Models; Cells; Code; Disease; Eukaryota; Gene Expression; Gene Expression Regulation; Genetic; Goals; Herpesviridae; Homeostasis; Laboratories; Link; Mammalian Cell; Mechanics; Mediating; Messenger RNA; MicroRNAs; Molecular Biology; Primates; RNA; RNA Binding; RNA Splicing; Research; Ribonucleoproteins; Saimiriine Herpesvirus 2; Seeds; Small Nuclear RNA; Spider Monkey; Techniques; Untranslated RNA; Untranslated Regions; Viral; Viral Cancer; Virus Diseases; Work; flexibility; gammaherpesvirus; genome-wide; in vivo; interest; mRNA Precursor; novel; particle; snRNP Structural Core Protein

Summary The overarching goal of my laboratory is to define the functions and mechanisms of a group of non- coding RNAs (ncRNAs): the small nuclear, U-rich RNAs (snRNAs). Cellular snRNAs associate with Sm proteins to form ribonucleoprotein particles (RNPs) that are essential components of cellular machineries responsible for the precursor messenger RNA (pre-mRNA) processing steps of splicing and 3¢-end formation, and their perturbation underlies several diseases. Recent research from my lab and others suggests that this group of ncRNAs is more functionally diverse than previously thought and that the canonical functions of snRNAs in splicing and 3¢-end processing constitute only the tip of the iceberg. Using Herpesvirus saimiri (HVS) as a model system, we recently showed that snRNAs perform functions beyond pre-mRNA processing. This primate g-herpesvirus expresses seven snRNAs in latently infected cells called HSURs (Herpesvirus saimiri U-rich RNAs). We have focused on two of these ncRNAs, HSURs 1 and 2, because they are the most highly conserved HSURs among different HVS groups and the only two expressed by the related Herpesvirus ateles. HSUR1 and HSUR2 basepair with host microRNAs (miRNAs) and target one miRNA, miR-27, for degradation. Work from our laboratory showed that HSUR2 also basepairs with host mRNAs and links bound miRNAs with specific mRNAs to destabilize them. This constitutes the first example of an snRNA function after pre-mRNA processing. We also developed iRICC, a technique to determine RNA binding partners of a single RNA of interest and the sequences mediating RNA-RNA interactions in vivo. Using iRICC we showed that HSUR2 binding sites reside mostly in the 3¢ untranslated regions (3¢UTRs) of target mRNAs. We also showed that HSUR2 does not present a “seed” or specialized region that is used to interact with most targets, but rather acts as a flexible adaptor that interacts through different base-pairing arrangements with different mRNAs. iRICC revealed that HSUR1 profusely binds to coding sequences in addition to 3¢UTRs of target mRNAs. These findings suggest that HSUR1 might regulate host gene expression through mechanisms different from those employed by HSUR2. Finally, we have also developed an approach for identifying low-abundance snRNAs and discovered that mammalian cells express previously uncharacterized snRNAs. We will use a combination of genetic, genome-wide, molecular biology and biochemical approaches to further characterize mechanical aspects of HSUR1 and HSUR2 function and to functionally characterize novel cellular snRNAs. This work will advance our understanding of the mechanisms underlying the regulation of gene expression by this class on ncRNAs during viral infection. It will also illuminate novel mechanisms of gene regulation in the broad range of eukaryotes that express snRNAs.

概括 我实验室的总体目标是定义一组非 编码RNA (ncRNA)：小核、富含U的RNA (snRNA)。细胞 snRNA 与 Sm 蛋白相关 形成核糖核蛋白颗粒（RNP），它是细胞机器的重要组成部分，负责 前体信使RNA（pre-mRNA）剪接和3′端形成的加工步骤及其 扰动是多种疾病的根源。我的实验室和其他人的最新研究表明，这组 ncRNA 的功能比之前想象的更加多样化，并且 snRNA 的典型功能 拼接和3美分端加工仅构成冰山一角。 使用疱疹病毒 saimiri (HVS) 作为模型系统，我们最近表明 snRNA 执行功能 超越前 mRNA 加工。这种灵长类 g-疱疹病毒在潜伏感染的细胞中表达 7 个 snRNA 称为 HSUR（富含赛米里疱疹病毒的 RNA）。我们重点关注其中两个 ncRNA，HSUR 1 和 2， 因为它们是不同 HVS 群体中最高度保守的 HSUR，并且是唯一两个表达的 由相关的疱疹病毒ateles。 HSUR1 和 HSUR2 与宿主 microRNA (miRNA) 和靶标 1 的碱基对 miRNA、miR-27，用于降解。我们实验室的工作表明 HSUR2 也与宿主 mRNA 碱基配对 并将结合的 miRNA 与特定的 mRNA 连接起来以破坏它们的稳定性。这构成了 snRNA 的第一个例子 mRNA 前体加工后的功能。我们还开发了 iRICC，一种确定 RNA 结合伙伴的技术 单个感兴趣的 RNA 和介导体内 RNA-RNA 相互作用的序列。使用 iRICC 我们展示了 HSUR2 结合位点主要位于目标 mRNA 的 3￠非翻译区 (3￠UTR)。我们也 表明 HSUR2 不存在用于与大多数目标相互作用的“种子”或专门区域， 而是充当灵活的适配器，通过不同的碱基配对安排与不同的碱基配对相互作用 mRNA。 iRICC 揭示，除了靶标的 3￠UTR 之外，HSUR1 还大量结合编码序列 mRNA。这些发现表明 HSUR1 可能通过不同的机制调节宿主基因表达 来自 HSUR2 的雇员。最后，我们还开发了一种识别低丰度的方法 snRNA 并发现哺乳动物细胞表达以前未表征的 snRNA。 我们将结合遗传、全基因组、分子生物学和生化方法来 进一步表征 HSUR1 和 HSUR2 功能的机械方面，并在功能上表征新颖的 细胞 snRNA。这项工作将增进我们对监管机制的理解 病毒感染期间此类在 ncRNA 上的基因表达。它还将阐明新的机制 表达 snRNA 的广泛真核生物中的基因调控。