Coupling of Transcription with Pre-mRNA Metabolism

信使RNA的合成是基因表达的主要事件，对细胞的生命至关重要。mRNA的产生需要由pol II转录，并由一组蛋白质对初级转录物进行加工，这些蛋白质进行盖帽、剪接和切割/聚腺苷化。由聚合酶而非pol II合成的转录本不能正确地加工成成熟的mRNA。蛋白质网络：细胞核中存在蛋白质接触，将pol II转录与负责mRNA成熟的特定RNA加工事件偶联。本研究的目的是利用生物化学和遗传方法阐明哺乳动物细胞、青蛙卵母细胞和芽殖酵母中蛋白质如何通过通讯实现pol II转录与RNA包装和加工的偶联。我们的研究正在验证这样一种观点，即mRNA是由含有RNA pol II和RNA加工因子的“工厂”复合体制造的，这些因子通过一个被称为CTD的重复蛋白质结构域与mRNA接触。这个模型改变了我们对蛋白质的看法，蛋白质曾经被认为是独立运作的，但现在被认为是在细胞核中相互协调的。我们开始发现的转录和加工之间整合的一个重要功能结果是转录因子可以调节RNA加工的效率，相反，加工因子可以潜在地调节转录。这项工作可能有助于阐明mrna的转录和加工在正常条件下是如何被调节的，以及它们在疾病状态下是如何被错误调节的。前mrna的剪接缺陷是导致大部分遗传疾病的原因。这项工作的具体目的是：1.；比较与pol II转录偶联的RNA加工和包装与不偶联的RNA加工和包装的体内机制。2. 确定capping酶如何调节pol II转录以及pol II转录机制的组成部分如何调节capping。3. 为了确定pol II延伸率、CTD七肽序列和CTD c端如何影响RNA的包装、旋盖、剪接和3'端形成。4. 确定哺乳动物加工因子是否与体内延长pol II三元配合物有关，以及三元配合物的加工因子组成在延长期间如何变化？网站性能 ======================================== 节结束 ===========================================

EXCEED THE SPACE PROVIDED, The synthesis of messenger RNA is the primary event in gene expression and is central to the life of cells. mRNA production requires transcription by pol II and processing of the primary transcript by a set of proteins which carry out capping, splicing and cleavage/polyadenylation. Transcripts made in by polymerases other than pol II are not processed correctly into mature mRNA. A network of protein:protein contacts in the cell nucleus exists to couple transcription by pol II with the specific RNA processing events responsible for maturation of mRNA. The objective of this proposal is to elucidate how proteins communicate to achieve coupling of pol II transcription with RNA packaging and processing using biochemical and genetic approaches in mammalian cells, frog oocytes and budding yeast. Our research is testing the idea that mRNA is made by a "factory" complex containing RNA pol II and RNA processing factors which contact it through a repetitive protein domain called the CTD. This model has changed the way we think about proteins which were once thought to operate independently but are now thought to be co-ordinated with one another in the nucleus. One important functional consequence of the integration between transcription and processing that we are beginning to uncover is that transcription factors can regulate the efficiency of RNA processing and conversely processing factors can potentially regulate transcription. This work may help elucidate how the transcription and processing of mRNAs are regulated under normal conditions and how they become mis-regulated in the disease state. Defects in splicing resulting of pre-mRNA's are responsible for a large fraction of all inherited diseases. The specific aims of this work are: 1. To compare mechanisms of RNA processing and packaging that are coupled to pol II transcription with uncoupled processing and packaging of RNA in vivo. 2. To determine how how capping enzymes regulate pol II transcription and how components of the pol II transcription machinery regulate capping. 3. To determine how pol II elongation rate, CTD heptad sequences and the CTD C-terminus affect RNA packaging, capping, splicing and 3' end formation. 4. To determine whether mammalian processing factors associate with elongating pol II ternary complexes in vivo and how the processing factor composition of ternary complexes changes during elongation? PERFORMANCE SITE ========================================Section End===========================================