Mechanisms of Trinucleotide Repeat Expansion via Oxidative DNA Damage and Repair

我获得K99/R00奖的目的是将我的研究扩展到体内相互作用的研究 DNA重复序列不稳定性、DNA损伤与修复在人类疾病领域的相关研究 环境胁迫诱导的碱基切除修复介导的重复序列不稳定性 (BER)。长期目标是了解暴露在环境压力下如何影响 启动和调节重复序列与人类疾病的发生和发展 不稳定以及如何通过DNA损伤修复来防止环境诱导的影响。我 假设CAG重复与环境氧化DNA损伤及其低效BER有关 扩张。这一假说将通过两个具体目标进行探索。第一个目标是确定效率有多低 环境诱导氧化单链DNA断裂中间体的处理 致癌物、铬酸盐和溴酸盐可能参与CAG重复序列的扩增。不足的影响 单链DNA断裂对CAG重复扩增的处理将在Pol p DRP缺乏的情况下确定 裂解酶和FEN1裂解发夹结构。目标二是确定是否高效地处理 氧化的单链DNA断裂可以阻止CAG重复扩增。这一目标将通过确定是否 通过BER对单链DNA断裂中间产物进行有效处理，可以减少CAG重复扩增 APE1与POLp、XRCC1与POL3以及BLm与FEN1之间的蛋白质相互作用。在他的领导下， 在威尔逊的指导下，我在被指导期间成功地完成了我的研究和职业目标 奖励期的阶段。我已经建立了几种分析CAG重复不稳定的方法 体内和体外。这提高了我在体内分析TNR稳定性和误码率的技能和知识 生物化学。这也巩固了在独立阶段实现研究目标的基础 以及构建我未来的ROL提案。我未来的研究将重点放在以下领域的工作 环境氧化DNA诱导的重复序列不稳定性的细胞和生化研究 损坏。BER突变对三核苷酸重复序列稳定性和BER蛋白生化的影响。

My intention in obtaining ttie K99/R00 award is to extend my research into studies of in vivo interplay between DNA repeat sequence instability, DNA damage and repair in the field of human disease-associated repeat sequence instability that is induced by environmental stress and mediated by base excision repair (BER). IVIy long-term goal is to understand how exposure to environmental stress influences the development and progression of human diseases through initiating and modulating repeat sequence instability and how the environmentallv-induced effects can be prevented by DNA damage repair. I hypothesize that environmental oxidative DNA damage and its inefficient BER is involved in CAG repeat expansion. The hypothesis will be explored by two Specific Aims. Aim one is to determine how inefficient processing of oxidative single-strand DNA (ssDNA) break intermediates induced by environmental carcinogens, chromate and bromate may be involved in CAG repeat expansion. The impact of insufficient processing of ssDNA breaks on CAG repeat expansion will be determined under deficiency of Pol p dRP lyase and FEN1 cleavage of hairpin structures. Aim two is to determine if highly efficient processing of oxidative ssDNA breaks can prevent CAG repeat expansion. This aim will be examined by determining if CAG repeat expansion can be reduced by efficient processing of ssDNA break intermediates through BER protein interactions between APE1 and Pol p, XRCC1 and Pol 3, as well as BLM and FEN1. Under Dr. Wilson's mentoring, I have successfully accomplished my research and career goals during the mentored phase of the award period. I have established several approaches for analyzing CAG repeat instability in vivo and in vitro. This has advanced my skills and knowledge in analyzing in vivo TNR stability and BER biochemistry. This also consolidated the basis for fulfillment of research goals during the independent phase as well as construction of my future ROl proposals. My future research will emphasize work in the areas of cellular and biochemical studies on repeat sequence instability induced by environmental oxidative DNA damage. BER mutational effects on trinucleotide repeat stability and BER protein biochemistry.