Regulation of L1 retrotransposition

描述(申请人提供)：L1(长散布核素1)反转录转座子是人类基因组中最活跃的可移动元件。它们有50多万份。L1插入会扰乱基因功能，增加基因组的整体质量。尽管LLS数量丰富，但人们对LLS是如何监管的知之甚少。在这个提议中，我研究了哺乳动物细胞用来遏制L1对基因组损伤的三种可能的策略：1.修复由L1插入引起的或用于L1插入的双链DNA断裂。2.通过细胞凋亡来杀伤L1损伤插入的细胞。3.试图通过RNA干扰破坏L1 RNA来阻止L1插入。为了研究这些假设的L1调节模式，我的实验室开发了一种流式细胞仪来监测培养细胞中的L1逆转录转座。我们还创造了带有绿色荧光蛋白标签的L1转基因小鼠。更好地了解L1逆转录转座是如何调控的，将有助于对L1生物学、机制和L1在癌症基因组不稳定中的潜在贡献产生重要的见解。

DESCRIPTION (provided by applicant): L1 (Long Interspersed Nuclear Element 1) retrotransposons are the most active mobile elements in the human genome. They are present in over 500,000 copies. L1 insertions can disrupt gene function and add to the overall mass of the genome. Despite their abundance, very little is known about how Lls are regulated. In this proposal, I investigate three potential strategies used by mammalian cells to contain L1 damage to the genome: 1. Repair double stranded DNA breaks that are caused by or used for L1 insertions. 2. Kill cells with damaging L1 insertions by apoptosis. 3. Try to prevent L1 insertion by using RNA interference to destroy L1 RNA. To investigate these hypothesized modes of L1 regulation, my lab has developed a flow cytometric assay to monitor L1 retrotransposition in cultured cells. We have also created mice with green fluorescent protein tagged L1 transgenes. A better understanding of how L1 retrotransposition is regulated should yield important insights into L1 biology, mechanism and the potential of L1s to contribute to genomic instability in cancer.