The role of nonsense-mediated mRNA decay in embryonic stem cell gene expression

描述(申请人提供)：基因表达是一个复杂的过程，包括细胞的遗传信息从其DNA到信使核糖核酸分子，然后到功能蛋白质的顺序转移。特定的RNA监测机制监测这一过程，并负责降解有缺陷的mRNAs，以保护细胞免受异常蛋白的产生。无意义介导的mRNA衰变(NMD)是一种保守的RNA监测途径，它检测和破坏编码提前终止密码子(PTCs)的mRNAs，从而阻止截短产物的翻译。作为疾病病理的重要调节因子，NMD通路是目前正在开发的几种治疗策略的靶点。除了靶向异常的mRNAs外，NMD还调节正常的基因表达，通常是通过调节选择性剪接的变化。此外，在多种生物中，NMD是胚胎正常发育所必需的。然而，尽管有大量的研究，但这一过程在细胞内稳态中的作用以及控制其活动的机制仍然不完全清楚。这项建议使用高通量测序结合分子生物学和计算技术来研究NMD途径在小鼠胚胎干细胞(MESC)基因表达中的作用。为了实现这一目标，将确定那些其稳定性和翻译效率受NMD调节的mRNA异构体，以及决定其对这一途径的易感性的mRNA特征。与UPF1直接相关的信息也将被识别出来，UPF1是NMD途径的一个重要组成部分。这些研究的结果将阐明这种RNA监测途径对基因表达的影响的广度，以及这些影响在多大程度上超出了异常mRNA分子的清除，这些问题与理解NMD抑制疗法的影响特别相关。此外，这些研究将专门讨论关键的NMD因子UPF1在早期发育的mRNA表达中的作用，并可能有助于解释胚胎发生依赖于NMD途径的原因。好了！

DESCRIPTION (provided by applicant): Gene expression is a complex process that encompasses the sequential transfer of a cell's genetic information from its DNA into mRNA molecules and then into functional proteins. Specific RNA surveillance mechanisms monitor this process and are responsible for degrading defective mRNAs to protect the cell from producing aberrant proteins. Nonsense-mediated mRNA decay (NMD) is a conserved RNA surveillance pathway that detects and destroys mRNAs encoding premature termination codons (PTCs), thus preventing the translation of truncated products. As an important modulator of disease pathology, the NMD pathway is the target of several therapeutic strategies currently in development. In addition to targeting aberrant mRNAs, NMD also regulates normal gene expression, often via regulated changes in alternative splicing. Furthermore, NMD is required for proper embryonic development in multiple organisms. Despite significant research, however, the role of this process in cellular homeostasis and the mechanisms that govern its activity remain incompletely understood. This proposal uses high-throughput sequencing combined with molecular biological and computational techniques to investigate the role of the NMD pathway in mouse embryonic stem cell (mESC) gene expression. Towards this goal, those mRNA isoforms whose stability and translational efficiency are regulated by NMD and the mRNA features that determine their susceptibility to this pathway will be determined. Messages that directly associate with Upf1, an essential component of the NMD pathway, will also be identified. The results of these studies will illuminate the breadth of the impact that this RNA surveillance pathway has over gene expression and the extent to which these effects extend beyond the clearing of aberrant mRNA molecules, questions particularly relevant to understanding the repercussions of NMD-suppression therapies. Furthermore, these studies will specifically address the role that the essential NMD factor, Upf1, has in mRNA expression in early development and may help to explain the reasons for the dependency of embryogenesis on the NMD pathway. !