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

 描述(由申请人提供)：非编码RNA(NcRNAs)已成为遗传调控系统中的关键角色。SM类RNA是一组在重要的代谢过程中起重要作用的ncRNA，如前ʹ剪接和3‘端加工等。然而，更多的Sm类RNA已经被发现，我们已经获得证据表明它们在基因调控中发挥功能。我们现在建议表征这一独特的Sm-类RNA的新功能子集的靶标和作用机制。这项建议侧重于确定病毒和细胞来源的新的Sm-类RNA的功能。塞米里疱疹病毒是一种致癌性γ疱疹病毒，可感染T细胞，并在新大陆灵长类动物中引起侵袭性淋巴瘤和白血病。人类疱疹病毒表达7个Sm类RNA，称为HSURs(疱疹病毒富含U-RNAs)，功能未知。初步研究表明，HSURs 1和2：1)促进人类免疫缺陷病毒转化的T细胞存活；2)与主动翻译的宿主mRNAs有关；3)还与宿主miRNAs(miR-27、miR-16和miR-142-3p)和富含AU的元件(Are)结合蛋白有关；4)下调靶mRNAs。因此，我们假设HSUR1和2通过招募抑制性miRNA和ARE结合蛋白复合体来抑制靶mRNAs。我们进一步假设，这些活动重新连接了关键的宿主途径，以抑制潜伏感染细胞的凋亡。我们的初步数据还发现了几个似乎在人类细胞系中表达的新的Sm类RNA。我们现在建议测试病毒Sm类RNA如何有助于人类免疫缺陷病毒介导的T细胞转化，并表征新的人类Sm类RNA的功能。这一建议结合了生物化学、遗传学和高通量测序，目的是定义哪些细胞通路可能受人类免疫缺陷病毒通过潜伏感染细胞中的HSURs 1和2调节(目标1)，确定HSURs如何选择和抑制它们的靶mRNAs(目标2)，并表征新发现的人类Sm类RNA的功能(目标3)。完成这些目标将加深我们对宿主-病毒相互作用的理解，可能导致更好的治疗方法来对抗这些感染。更重要的是，它还将扩大我们对一类未被研究的ncRNAs的理解，并阐明一种可能在表达Sm类ncRNAs的广泛真核生物中使用的新的调控机制。

 DESCRIPTION (provided by applicant): Non-coding RNAs (ncRNAs) have emerged as key players in genetic regulatory systems. Sm-class RNAs constitute a group of ncRNAs with essential roles in important metabolic processes such as pre-mRNA splicing and 3ʹ′-end processing. However, additional Sm-class RNAs have been identified, and we have obtained evidence that they function in gene regulation. We now propose to characterize the targets and mechanisms of action of this distinct new functional subset of Sm-class RNAs. This proposal focuses on determining the functions of novel Sm-class RNAs of both viral and cellular origin. Herpesvirus saimiri (HVS) is an oncogenic γ-herpesvirus that infects T cells and causes aggressive lymphomas and leukemias in New World primates. HVS expresses seven Sm-class RNAs called HSURs (Herpesvirus saimiri U-rich RNAs), of unknown function. Preliminary studies show that HSURs 1 and 2: i) promote the survival of HVS-transformed T cells, ii) associate with actively translated host mRNAs, iii) also associate with host miRNAs (miR-27, miR-16, and miR-142-3p) and AU-rich element (ARE)-binding proteins, and iv) downregulate the target mRNAs. We therefore hypothesize that HSURs 1 and 2 repress target mRNAs by recruiting inhibitory miRNA and ARE-binding protein complexes. We further hypothesize that these activities rewire key host pathways to inhibit apoptosis of latently infected cells. Our preliminary data also identify several new Sm-class RNAs that appear to be expressed in human cell lines. We now propose to test how viral Sm- class RNAs contribute to HVS-mediated T cell transformation, and to characterize the functions of novel human Sm-class RNAs. This proposal combines biochemistry, genetics, and high-throughput sequencing with the aim of defining which cellular pathways are likely regulated by HVS through HSURs 1 and 2 in latently infected cells (Aim 1), determining how HSURs select and repress their target mRNAs (Aim 2), and characterizing the functions of newly identified human Sm-class RNAs (Aim 3). Completion of these aims will deepen our understanding of host-virus interactions, potentially leading to better therapies to combat these infections. More importantly, it will also expand our understanding of an understudied class of ncRNAs and illuminate a novel mechanism of regulation likely used in the broad range of eukaryotes that express Sm-class ncRNAs.