Regulation of Small RNAs by the eri-1 Genetic Pathway

描述（由申请人提供）：许多生物体暴露于双链RNA会导致含有与触发dsRNA同源序列的mRNA分子的降解，这一过程称为RNAi。对模式生物（如秀丽隐杆线虫）的遗传和生化分析表明，RNAi的许多机制基础是进化保守的。在RNAi领域仍有许多基本问题有待解决，包括：(1)RNAi机制的内源性生物学功能是什么；(2) RNAi是否像大多数生物过程一样受到负调控？我们已经进行了基因筛选，以寻找RNAi的负调控因子。到目前为止，这些研究已经确定了基因eri-1的特征。结果表明，ERI-1负调控R；通过降解RNAi的小RNA刽子手（sirna）。我们现在已经开始描述在与eri-1（称为eri-1途径）的遗传途径中起作用的另外四个基因。我们的初步数据表明，eri-1途径蛋白与秀丽隐杆线虫dicer样蛋白DCR-1复合物一起调节siRNA的稳定性。最后，我们的数据表明eri-1通路蛋白是一种新的基因调控模式所必需的，我们称之为内源性RNAi。本提案旨在：(1)详细表征ERI-1的分子功能；(2)继续进行eri-1通路基因的遗传分析；(3)阐明eri-1通路基因在秀丽隐杆线虫小rna的生物发生和功能中的作用。利用sirna靶向致癌蛋白和病毒蛋白的初步成功让人兴奋，sirna最终可能用于治疗人类疾病。在使用sirna治疗人类疾病之前，了解小rna的内源性生物活性以及这些小rna是如何产生和调节的至关重要。

DESCRIPTION (provided by applicant): Exposure of many organisms to double-stranded RNA causes the degradation of mRNA molecules containing sequences homologous to the trigger dsRNA, a process termed RNAi. Genetic and biochemical analysis in model organisms, such as C. elegans, has demonstrated that much of the mechanistic underpinnings of RNAi are evolutionary conserved. Many fundamental questions remain to be addressed in the RNAi field including: (1) What are the endogenous biological functions of the RNAi machinery; and (2) Is RNAi, like most biological processes, under negative regulation? We have undertaken a genetic screen seeking to identify negative regulators of RNAi. These studies have thus far led to the characterization of the gene eri-1. Our results suggest that ERI-1 functions to negatively regulate R;NAi by degrading the small RNA executioners of RNAi (siRNAs). We have now begun to characterize four additional genes which function in a genetic pathway with eri-1 (termed the eri-1 pathway). Our preliminary data suggests that the eri-1 pathway proteins function in a complex with the C. elegans Dicer-like protein DCR-1 to regulate siRNA stability. Finally, our data indicate that the eri-1 pathway proteins are required for a novel mode of gene regulation, a process we term endogenous RNAi. This proposal seeks to: (1) characterize the molecular function of ERI-1 in detail; (2) continue our genetic analysis of the eri-1 pathway genes; and (3) elucidate the role of the eri-1 pathway genes in the biogenesis and function of small RNAs in C. elegans. Initial successes utilizing siRNAs to target oncogenic and viral proteins have generated excitement that siRNAs may eventually be utilized to treat human disease. Understanding the endogenous biological activities of small RNAs and how these small RNAs are generated and regulated is essential prior to the rationale use of siRNAs in treating human disease.