Mechanisms of Trinucleotide Repeat Expansion via Oxidative DNA Damage and Repair

我获得K99/R 00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损伤与修复之间的关系在人类疾病相关领域 由环境胁迫诱导并由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于环境压力如何影响 通过启动和调节重复序列来发展和进展人类疾病 不稳定性以及如何通过DNA损伤修复来预防环境引起的影响。我 假设CAG重复序列与环境氧化性DNA损伤及其低效BER有关 扩张.该假设将通过两个具体目标进行探讨。目的一是确定效率有多低 由环境诱导的氧化性单链DNA（ssDNA）断裂中间体的加工 致癌物铬酸盐和溴酸盐可能参与CAG重复扩增。不足的影响 将在Pol p dRP缺陷的情况下确定CAG重复扩增上ssDNA断裂的加工 发夹结构的裂解酶和FEN 1裂解。目的二是确定是否高效处理 氧化性ssDNA断裂可防止CAG重复扩增。这一目标将通过确定是否 CAG重复扩增可以通过BER有效处理ssDNA断裂中间体来减少 APE 1和Pol p、XRCC 1和Pol 3以及BLM和FEN 1之间的蛋白质相互作用。在Dr. 在Wilson的指导下，我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重复不稳定性的方法， 体内和体外。这提高了我在分析体内TNR稳定性和BER方面的技能和知识 生物化学这也为实现独立阶段的研究目标奠定了基础 以及我未来的投资建议。我未来的研究将侧重于以下领域的工作： 环境氧化DNA诱导重复序列不稳定性的细胞和生化研究 损害BER突变对三核苷酸重复稳定性和BER蛋白生物化学的影响。

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.