Mechanisms of dsRNA-induced gene silencing

描述（申请人提供）：RNA干扰已成为基因调控和基因组结构控制的关键途径。它还成为将基因组测序所揭示的词典翻译成功能词典的强大工具，其中包括每个基因的定义。理解RNAi途径的生物学相关性并利用该途径作为一种工具，在很大程度上都取决于破译这种基因沉默反应的生化基础。本申请中描述的工作通过结构生物学、生物化学和遗传学在果蝇、哺乳动物、秀丽隐杆线虫和植物等系统中的应用，继续我们对RNAi机制基础的研究。具体来说，决定小rna如何进入RISC的信号，RNAi效应复合体将从rna本身和处理它们的蛋白质的角度进行探索。RNAi效应复合物RISC的结构和酶学将在RNA裂解反应中进行研究，并寻求RISC在没有RNA裂解的情况下抑制蛋白质合成的机制。最后，遗传学和生物化学将应用于RNAi和染色质结构之间的相互作用，这似乎是这种灵活沉默途径的另一个进化保守效应臂。这些研究如果成功，将对保守的沉默机制产生根本性的见解，并带来珩磨工具的额外好处，这些工具既可用于发现新的治疗靶点，也可用于潜在的治疗方法本身。

DESCRIPTION (provided by applicant): RNA interference has emerged as a key pathway in gene regulation and the control of genome structure. It has also become a powerful tools for translating the lexicon that was revealed by genomic sequencing into a functional dictionary, complete with the definition of each gene. Understanding the biological relevance of the RNAi pathway and harnessing this pathway as a tool have both depended to a large degree on deciphering the biochemical basis of this gene silencing response. The work described in this application continues our studies of the mechanistic basis of RNAi through the application of structural biology, biochemistry and genetics in systems including Drosophila, mammals, C. elegans and plants. Specifically, the signals that determine how small RNAs enter RISC, the RNAi effector complex will be probed both from the perspective of the RNAs themselves and of the proteins that process them. The architecture and enzymology of RISC, the RNAi effector complex, will be examined during an RNA cleavage reaction, and the mechanism by which RISC can suppress protein synthesis in the absence of RNA cleavage will be sought. Finally, genetics and biochemistry will be applied to gain traction on the interactions between RNAi and chromatin structure that seem to be another evolutionary conserved effector arm of this flexible silencing pathway. These studies, if successful, will produce fundamental insights into a conserved silencing machinery with the additional benefit of honing tools that are being applied both for the discovery of new therapeutic targets and as potential therapeutics themselves.