Regulation of HIV-1 RNA Processing

超出所提供的空间。整合的HIV-1前病毒基因组被宿主转录机制转录成一个9.2 kb的初级转录物。为了表达病毒复制所需的九种不同的基因产物，HIV已经开发了许多策略来调节剪接并规避限制细胞质中未剪接RNA的细胞机制。调节蛋白Rev促进不完全剪接的病毒RNA向细胞质的转运，与病毒RNA上的Rev应答元件（RRE）结合。调节未剪接和剪接病毒RNA的出现及其向细胞质转运的机制涉及病毒RNA序列与宿主细胞因子之间的相互作用。这些病毒/宿主相互作用的特征可以允许设计新的治疗化合物。在一系列体外实验中，hnRNP - H蛋白已被证明是HIV-1 RNA剪接所必需的。它们还可能调节受感染细胞中的RNA输出和运输。hnRNP H蛋白家族的单个成员在体内HIV-1 RNA加工中的作用将通过在转染HIV-1衍生质粒的细胞中调节hnRNP H蛋白的表达来研究，这些质粒在调控序列上发生突变。在体外已经确定了几个调节病毒RNA剪接的病毒序列。将对这些进行测试，以确定它们是否对体内病毒RNA剪接的调节是必要的。初步数据表明，病毒序列与RRE-Rev复合物相互作用，并可能在rev依赖的病毒RNA转运途径中发挥作用。这些相互作用将通过体内和体外分析的组合来表征。在其他系统中，转录和剪接已被证明是紧密耦合的。初步数据表明，病毒启动子在体外影响病毒底物的剪接。HIV-1转录和剪接可能的耦合将被研究，使用耦合转录-剪接实验和瞬时转染实验。网站性能 ======================================== 节结束 ===========================================

EXCEED THE SPACE PROVIDED. The integrated HIV-1 proviral genome is transcribed by the host transcription machinery into a single 9.2 kb primary transcript. To express the nine different gene products required for viral replication, HIV has developed a number of strategies to regulate splicing and to circumvent cellular mechanisms restricting unspliced RNA in the cytoplasm. The regulatory protein Rev promotes transport of the incompletely spliced viral RNAs to the cytoplasm, binding to the Rev Responsive Element (RRE) on the viral RNA. Mechanisms regulating the appearance of unspliced and spliced viral RNAs, and their transport to the cytoplasm, involve interactions between viral RNA sequences and host cell factors. The characterization of these viral/host interactions could allow the design of novel therapeutic compounds. hnRNP H proteins have been shown to be necessary for HIV-1 RNA splicing in a series of in vitro experiments. They may also regulate RNA export and trafficking in infected cells. The role of single members of the hnRNP H protein family in HIV-1 RNA processing in vivo will be investigated by modulating hnRNP H protein expression in cells transfected with HIV-1-derived plasmids, bearing mutations in regulatory sequences. Several viral sequences that regulate viral RNA splicing in vitro have been identified. These will be tested to determine whether they are necessary for the regulation of viral RNA splicing in vivo. Preliminary data indicates that viral sequences interact with the RRE-Rev complex and, possibly, have a role in the Rev-dependent viral RNA transport pathway. These interactions will be characterized by a combination of in vivo and in vitro assays. Transcription and splicing have been shown to be closely coupled in other systems. Preliminary data indicates that the viral promoter influences splicing of viral substrates in vitro. Possible coupling of HIV-1 transcription and splicing will be investigated, using both a coupled transcription-splicing assay and transient transfection experiments. PERFORMANCE SITE ========================================Section End===========================================