Regulation of HIV-1 RNA Processing

超出所提供的空间。 整合的HIV-1前病毒基因组由宿主转录机器转录成单个9.2kb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转运至细胞质，与病毒RNA上的Rev应答元件（RRE）结合。调节未剪接和剪接的病毒RNA的出现及其向细胞质的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/宿主相互作用的表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蛋白已显示为HIV-1 RNA剪接所必需。它们还可以调节RNA输出和感染细胞中的运输。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调节用HIV-1衍生质粒转染的细胞中的hnRNP H蛋白表达来研究，所述质粒在调控序列中具有突变。已经鉴定了几种在体外调节病毒RNA剪接的病毒序列。将对这些进行测试，以确定它们是否是体内调节病毒RNA剪接所必需的。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依赖性病毒RNA转运途径中发挥作用。这些相互作用将通过体内和体外试验的组合来表征。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，病毒启动子影响病毒底物在体外的剪接。可能的耦合HIV-1的转录和剪接将进行调查，使用耦合转录剪接试验和瞬时转染实验。性能现场=

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===========================================