Coupling of transcription elongation and termination with pre-mRNA processing

项目总结/摘要 信使RNA（mRNA）的产生是基因表达的主要事件， 信息从基因的DNA转移到一次性的RNA拷贝中。腐败这 这个过程是包括癌症在内的许多疾病的标志。mRNA合成不仅需要 RNA转录物合成，但转录物通过5 ′加帽、内含子切除 以及外显子的剪接和通过切割和polyA尾添加的3'末端形成。的mRNA 从根本上转化初级转录物的加工步骤主要以共转录方式发生; 也就是说，mRNA加工的底物是生长中的新生RNA， RNA聚合酶II（pol II）分子的速率为500-5000碱基/分钟。我们的工作模型是， mRNA前体的合成和加工以整合的方式在细胞内进行， 包括RNA聚合酶和加工因子的动态“mRNA工厂”复合体 其中一些与pol II C-末端结构域（CTD）直接接触。我们工作的目标 是为了了解RNA链的转录生长是如何与其折叠协调的， RNA二级结构，它与RNA结合蛋白的结合，以及它的成熟， 剪接和3 ′末端形成。新生RNA代谢的这些重要特征都是 受到RNA链增长速度的影响。因此，重要的是要发现如何速度 pol II在其沿沿着基因传播时受到控制。当波尔二号完成了它的旅程， 基因，高度稳定的转录延伸复合物必须积极拆卸回收 阻止它侵入邻近的基因。我们将研究这个过程 转录终止是在基因的3'端以精心控制的方式实现的， 也可以在基因内“过早”发生终止。我们将使用基因和基因组 在人类细胞中研究这三个关键挑战的方法： I.前体mRNA加工、新生RNA折叠、RNA合成和转录之间的关系是什么？ 结合蛋白（RBP）结合，转录延伸？ 二.转录延伸的速度是如何调节的？ 三.什么机制终止了pol II在基因内和下游的转录？ 基因？

Project Summary/Abstract The production of messenger RNA (mRNA) is the primary event in gene expression where genetic information is transfered from the gene’s DNA into a disposable RNA copy. Corruption of this process is a hallmark of many diseases including cancer. mRNA synthesis requires not only synthesis of an RNA transcript but maturation of that transcript by 5’ capping, excision of introns and splicing of exons and 3’ end formation by cleavage and polyA tail addition. The mRNA processing steps that radically transform the primary transcript occur largely co-transcriptionally; that is to say the substrate of mRNA processing is the growing nascent RNA that is extruded by an RNA polymerase II (pol II) molecule at rates of 500-5000 bases/min. Our working model is that synthesis and processing of a mRNA precursor are carried out in an integrated fashion within a dynamic 'mRNA factory' complex that includes both RNA polymerase and processing factors some of which make direct contacts with the pol II C-terminal domain (CTD). The goal of our work is to understand how growth of the RNA chain by transcription is coordinated with its folding into RNA secondary structures, its association with RNA binding proteins, and its maturation by splicing and 3’ end formation. These important features of nascent RNA metabolism are all affected by how fast the RNA chain grows. Therefore it is important to discover how the speed of pol II is controlled as it travels along genes. When pol II completes its journey to the end of the gene, the highly stable transcription elongation complex must be actively disassembled to recycle the enzyme and prevent it from invading neighboring genes. We will investigate how the process of transcription termination is achieved in carefully controlled ways at the 3’ ends of genes and also within genes where termination can occur “prematurely”. We will use genetic and genomic approaches in human cells to investigate these three Key Challenges: I. What is the relation between pre-mRNA processing, nascent RNA folding, RNA binding protein (RBP) binding, and transcription elongation? II. How is the speed of transcription elongation regulated? III. What mechanisms terminate pol II transcription within genes and downstream of genes?