The Role of the PIWI Proteins in Maintaining Genome Integrity

 描述(由申请人提供)：DNA损伤的积累可能导致基因突变的引入和基因组不稳定性的增加。基因组不稳定与包括癌症和神经退行性疾病在内的几种人类疾病有关。新出现的证据表明，非编码RNA途径有助于维持基因组的稳定性。一种这样的非编码RNA途径是PIWI/piRNA途径。PIWI蛋白家族是ArgAerte蛋白的一个亚家族，以DICER独立的方式参与称为PiRNAs(Piwi相互作用RNAs)的小分子非编码RNA的生物发生。已知PIWI/PiRNA途径通过转录后修饰和表观遗传修饰抑制基因表达。最近，PIWI/piRNA途径被认为有助于维持基因组的完整性。具体地说，缺乏PIWI蛋白的果蝇在卵子发生过程中表现出DNA损伤增加和减数分裂检查点激活。这项提案的目标1中定义的工作将使用新的基于深度测序的技术来表征PIWI缺陷果蝇在碱基对分辨率下发生的DNA损伤和基因组不稳定性的类型。在目标2中，将确定PIWI蛋白帮助维持基因组稳定的机制，重点是PIWI-piRNA途径如何与DNA损伤检查点机制相互作用，以确保基因组的完整性。

 DESCRIPTION (provided by applicant): The accumulation of DNA damage can lead to the introduction of genetic mutations and an increase in genomic instability. Genomic instability is associated with several human diseases including cancer and neurodegenerative diseases. Emerging evidence suggests that non-coding RNA pathways contribute to maintaining genome stability. One such non-coding RNA pathway is the PIWI/piRNA pathway. The PIWI family of proteins is a subfamily of Argonaute proteins and is involved in the biogenesis of small non-coding RNAs termed piRNAs (Piwi interacting RNAs) in a Dicer independent fashion. The PIWI/piRNA pathway is known to suppress gene expression through posttranscriptional and epigenetic modifications. Recently the PIWI/piRNA pathway has been implicated in helping to maintain genome integrity. Specifically, Drosophila that lack PIWI proteins shows increased DNA damage and an activated meiotic checkpoint during oogenesis. The work defined in Aim 1 of this proposal will characterize the type of DNA damage and genomic instability that occurs in PIWI deficient Drosophila at the basepair resolution using novel deep-sequencing based techniques. In Aim 2, the mechanism used by PIWI proteins to help maintain genome stability will be determined, with a focus on how the PIWI-piRNA pathway interacts with the DNA damage checkpoint mechanism to ensure genome integrity.