Structure and function of cloverleaf RNA in enterovirus

摘要 人类肠道病毒引起的疾病范围从普通感冒这样的轻微疾病。 到严重的疾病，如脊髓灰质炎和心肌炎。例如，炎症和虚弱的心脏 柯萨奇B3病毒(CBV3)引起的心肌(心肌炎)可导致心力衰竭。大约10-15 美国每年有数百万人感染肠道病毒，但目前还没有抗病毒疗法 可用。我们的长期目标是获得详细的结构和生化信息 肠道病毒复制过程，并利用这些信息开发抗病毒治疗药物和 疫苗。在肠道病毒和其他正链rna病毒中，rna基因组被用作 蛋白质翻译和RNA合成，因此这些病毒需要一种机制来平衡相对的 这两个进程的范围。肠道病毒在5‘端使用’三叶草‘四向连接的RNA结构 作为宿主蛋白、聚(RC)结合蛋白2(PCBP2)和病毒的结合部位 编码蛋白3CD，并调节病毒蛋白翻译和RNA基因组合成的相对水平。 该项目的目标是了解三叶草RNA是如何与这些宿主和病毒蛋白相互作用的 平衡蛋白质翻译和基因组合成，以确保有效复制。为了实现这些目标，我们 将确定柯萨奇病毒基因组的5‘三叶草的结构，并表征其与 PCBP2使用互补的结构、生化和生物物理方法。三叶草的结构 被预测在肠道病毒、鼻病毒和其他小核糖核酸病毒中保守，因此我们的研究将 告知三叶草RNA的3D结构如何调节病毒在这一大类病毒中的复制。

Abstract Human enteroviruses are responsible for diseases that range from mild conditions like the common cold to severe diseases such as poliomyelitis and myocarditis. For example, the inflammation and weakening of the heart muscle (myocarditis) caused by coxsackie B3 virus (CBV3) can lead to heart failure. Approximately 10-15 million people are infected with enteroviruses in the US each year, yet no antiviral therapies are currently available. Our long-term goal is to obtain detailed structural and biochemical information regarding the enterovirus replication process, and to use this information for the development of antiviral therapeutics and vaccines. In enteroviruses and other positive-strand RNA viruses, the RNA genome is used as a template for both protein translation and RNA synthesis, and thus these viruses need a mechanism to balance the relative extents of these two processes. Enteroviruses use a ‘cloverleaf’ four-way junction RNA structure at the 5’ ends of their genomes to serve as a binding site for the host protein, poly(rC)-binding protein 2 (PCBP2) and the virally encoded protein 3CD, and to modulate the relative levels of viral protein translation and RNA genome synthesis. The goal of the project is to understand how the cloverleaf RNA interacts with these host and virus proteins to balance protein translation and genome synthesis to ensure efficient replication. To accomplish these goals, we will determine the structure of 5’ cloverleaf of the coxsackie virus genome and characterize its interactions with PCBP2 using complementary structural, biochemical, and biophysical approaches. The structure of cloverleaf is predicted to be conserved in enterovirus, rhinovirus, and other picornaviruses, and hence our studies will inform how the 3D structure of cloverleaf RNA regulates viral replication in this large class of viruses.