鲍曼不动杆菌Rosf-1蛋白在活性氧应答中的功能及机制研究

鲍曼不动杆菌是一种极具危害的临床致病菌，严重威胁人类健康。能够抵抗宿主产生的活性氧（ROS），是其能持续感染人体的一个重要原因，但调控通路尚未完全阐明。前期研究中，我们基于自行开发的CBE碱基编辑工具构建基因失活文库，筛选发现rosf-1基因失活株可被小鼠免疫系统清除。结构预测显示Rosf-1蛋白N端为DNA结合基序。预实验证实rosf-1敲除株的过氧化氢（一种ROS）敏感性增加，致病性减弱。我们推测Rosf-1通过调控ROS应答影响菌株致病性。本项目拟通过RNA-seq、CHIP-seq、基因编辑、动物感染模型等技术，鉴定Rosf-1的ROS降解通路靶基因、上游调控因子及保守结合位点，揭示Rosf-1蛋白中重要氨基酸位点，探索Rosf-1对ROS非降解通路的调控功能及其对致病性等生物学功能的影响。该研究有望丰富鲍曼不动杆菌的ROS应答网络，为后续药物靶标探索和治疗方法开发提供新的思路。

Acinetobacter baumannii is one of the most threatening clinical pathogens, which poses a serious threat to human health. The ability to resist the reactive oxygen species (ROS) produced by host is an important reason for A. baumannii to infect human body continuously, but the regulatory pathway is not fully elucidated. In the previous study, we constructed a gene inactivation library of A. baumannii based on the cytidine base editing tool developed by ourselves, and screened the rosf-1 inactivation strain could be eliminated by the immune system of mice. Structure prediction showed that the N-terminal of the Rosf-1 protein was a helix-turn-helix DNA binding motif. Preliminary experiment confirmed that the sensitivity of the rosf-1 deletion strain on hydrogen peroxides (one kind of ROS) was increased, and the pathogenicity of the rosf-1 deletion strain was decreased. We speculate that the Rosf-1 protein affects the pathogenicity of A. baumannii by regulating the ROS response. In this project, we plan to identify the target genes in the ROS degradation, the upstream regulators, and the conserved binding sites of Rosf-1, reveal the key amino acid sites in the Rosf-1 protein, explore the regulation function of the Rosf-1 on the ROS non-degradation pathway and its influence on pathogenicity and other biological functions using multiple biological technologies, such as RNA-seq, CHIP-seq, gene editing and animal infection models. This project is expected to enrich the ROS response network in A. baumannii, and shed a new insight on the exploration of potential drug targets and the development of new therapeutics against A. baumannii infections.