跨损伤DNA合成（TLS）通路与基因组变异和肿瘤耐药性产生密切相关，抑制TLS不仅有助于降低肿瘤耐药性，还能和ATR抑制剂联用产生协同致死效果，因此关于其调控机制和干预手段研究一直是DNA损伤应答领域一个热点。蛋白质乙酰化修饰在多种生命活动中发挥重要作用，然而关于乙酰化修饰在TLS通路中的调控作用至今仍是空白。在前期研究中，申请人通过质谱分析发现TLS聚合酶Polη上存在多个乙酰化修饰位点，部分位点的模拟乙酰化修饰能干扰紫外辐射后Polη在复制叉处的募集/停留，降低细胞的TLS活性。本项目将整合多种分子和细胞生物学技术、结合小鼠模型，深入研究Polη 乙酰化修饰对其在DNA损伤位点募集、对TLS活性和肿瘤耐药性的影响，阐明该修饰调控TLS通路的作用机制；寻找调控Polη 动态乙酰化修饰的酶，解析其调控机制，为化学干预Polη动态乙酰化修饰来改善肿瘤化疗效果奠定基础。

Translesion DNA synthesis (TLS) is closely related to genome mutagenesis and chemotherapeutic drug resistance. TLS Inhibition can not only reduce tumor drug resistance, but also promote synthetic lethality with ATR inhibitors. Therefore, it remains a hot topic in the field of DNA damage response to study how TLS pathway is regulated. Protein acetylation is important in many cellular Processes. So far, it remains a mystery how acetylation functions in TLS pathway. In our preliminary studies, we found that human Polη is subject to acetylation at some potential residues. Among them, several acetylation mimic mutants display impaired recruitment/retention at stalled replication forks and reduced TLS activity after UV irradiation. By integrating multiple cellular, biochemical and molecular techniques, this project aims at exploring the effects of Polη acetylation on its foci formation and TLS capacity after DNA damage as well as drug resistance, to understand the mechanism how acetylation regulates TLS. Meanwhile, we will explore the acetyltransferases and deacetylases responsible for the modification and determine how they dynamically regulate Polη acetylation status. We believe these results will provide important insights for drug intervention based on targeting Polη acetylation to improve chemotherapeutic efficacy.