A genomic approach to studying the life cycle of intron lariats

前体mRNA剪接是一个关键的和受调控的加工事件，其中内含子被 从新生RNA转录物中精确切除。在所有遗传性疾病中， 突变导致剪接缺陷。本研究探讨了分支点在 确定剪接位点选择（3 'ss）在体内被利用，并且分支点也具有 内含子的生命周期。每个前体mRNA剪接事件产生一个剪接的外显子 交界处。尽管人们对剪接外显子连接了解很多，但几乎一无所知 关于Lariats通过绘制人类基因组的所有分支点， 全新的分析领域。通过转录本数据识别分支点将 有助于临床测序数据的解释。除了内在价值之外， 这个数据，这个提案的成功完成将测试一些假设， 在真核基因的体内加工过程中发生的基本催化和识别。 在系统范围内研究这些中间体将带来生物化学水平的理解， 成千上万的处理事件。此外，每个内含子都有一个生命周期- 通过转录产物的剪接产生，通过脱支和降解回收。的 内含子的再循环对于补充游离核苷酸的细胞内水平至关重要， 使剪接因子回到活性剪接体。有些内含子在剪接后有了第二次生命 非编码RNA（ncRNA）。当我们对内含子的稳态水平进行采样时， 这两个过程。本建议试图通过探讨一些原因来跟踪这一线索 为什么某些内含子看起来很稳定

Pre-mRNA splicing is a critical and regulated processing event where introns are precisely excised from nascent RNA transcripts. As many as one third of all heritable disease mutations result in splicing defects. This research studies the role of branchpoints in determining splice site selection (3'ss) is utilized in vivo and also the effect branchpoints have on the life cycle of the intron. Each pre-mRNA splicing event creates a lariat and spliced exon junction. While a great deal is known about splice exon junctions almost nothing is known about lariats. By mapping all branchpoints in the human genome, we are opening up a whole new area of analysis. The identification of branchpoints by transcript data will facilitate the interpretation of clinical sequencing data. In addition to the intrinsic value of this data, the successful completion of this proposal will test some hypothesis about the fundamental catalysis and recognition that occurs in vivo in the processing of eukaryotic genes. Studying these intermediates at a system wide level will bring a biochemical-level understanding to hundreds of thousands of processing events. Furthermore, each intron lariat has a lifecycle - created by splicing of a transcribed product, recycled by debranching and degradation. The recycling of introns is vital to replenishing the intracellular levels of free nucleotides and to return splicing factors into active spliceosomes. Some introns have a second life after splicing as non-coding RNAs (ncRNAs). As we are sampling steady state levels of introns we gain insight into both these processes. This proposal seeks to follow this lead by exploring some of the reasons why certain introns appear stabilized.