RNA SPLICING CONTROL IN ROUS SARCOMA VIRUS

描述（改编自摘要）：该应用程序使用劳斯肉瘤 病毒（RSV）作为研究RNA加工调节的模型。 RSV原发性 转录本是由宿主RNA剪接机制剪接的，但这一过程 由于大部分（75%）的RNA保持未剪接， 作为gag-pol蛋白的信息和作为后代的基因组RNA 病毒粒子 正常处理不需要病毒蛋白 表明顺式元件在RNA中，并且是宿主来源的， 反式作用因子负责剪接与未剪接的比率， 核糖核酸 这项研究的特点，这些顺式和反式作用的因素。 一 控制元件已被确定，剪接的负调节因子 (NRS)，它位于gag中，其独特之处在于它不位于 在任何剪接位点附近，但抑制env和src 3剪接 sites（ss）. 已确定了NRS的两个分区域： 结合称为SR蛋白的必需剪接因子的富含嘌呤的区域 和未知因子（p55），以及用于 结合U11 snRNP，一种RNP颗粒，识别新的 一类罕见内含子（AT-AC内含子）。 U1和U2，丰富的snRNP的 主要剪接途径也与NRS RNA相互作用。 四个具体目标 被提议。 第一种使用体内和体外方法来进一步 描述控制NRS的顺式元件和反式作用因子 剪接抑制 第二个目的是检验一个假设，即U11 snRNP， 当与NRS结合时， 剪接因子存在于真实的3ss上，不包括与 真实的5 SS。 第三个目的是研究一种抑制src的因素 拼接，命名为SSS。 最后的目的是探讨的基础上， NRS和SSS在剪接抑制中的位置依赖性。 这可能是 受剪接位点竞争或相对于5 ′帽的位置的影响 结构

DESCRIPTION (Adapted from Abstract): This application uses the Rous sarcoma virus (RSV) as a model to study regulation of RNA processing. RSV primary transcripts are spliced by the host RNA splicing machinery, but this process is controlled since the majority (75%) of the RNA remain unspliced to serve as the message for the gag-pol proteins and as genomic RNA for progeny virions. Viral proteins are not required for the normal processing indicating that the cis elements are in the RNA and host-derived trans-acting factors are responsible for the ratio of spliced to unspliced RNA. This study characterizes these cis and trans-acting factors. One control element has been identified, the Negative regulator of splicing (NRS), which is located in gag and is distinctive in that it is not located near any of the splice sites, yet suppresses both the env and src 3 splice sites (ss). Two subregions of the NRS have been identified; an upstream purine-rich region that binds essential splicing factors called SR proteins and an unknown factor (p55), and a downstream sequence that is required for binding of U11 snRNP, an RNP particle that recognizes the 5 ss in a new class of rare introns (AT-AC introns). U1 and U2, abundant snRNPs of the major splicing pathway also interact with the NRS RNA. Four specific aims are proposed. The first uses in vivo and in vitro approaches to further characterize the cis elements and trans-acting factors which govern NRS splicing inhibition. The second aim tests a hypothesis that the U11 snRNP, when bound to the NRS interacts nonproductively with the major pathway splicing factors present at the authentic 3 ss, excluding pairing with the authentic 5 ss. The third aim studies an element which suppresses src splicing, named the SSS. The final aim investigates the basis of the position dependence of the NRS and SSS in splicing inhibition. This may be effected by splice site competition or the position relative to the 5' cap structure.