金葡菌蛋白酶系统调控蛋白质降解，维持细菌稳态平衡。ATP依赖蛋白酶ClpP在细菌应激反应、生物膜形成和毒力等方面发挥重要作用，但具体调节机制有待阐明。申请人前期工作提示ClpP对毒力调控蛋白SaeS有明显调节作用，clpP基因敲除后SaeS表达降低，且SaeS调控的下游靶基因表达明显降低。ClpP蛋白酶及其分子伴侣如何发挥对SaeS的调控作用？ClpP与SaeS之间是否存在相互调节关系？这种调节关系是否最终促进了细菌的毒力？为系统研究ClpP与SaeS之间的调节关系，本课题拟采取转录组和蛋白组学分析技术，从整体探讨ClpP与SaeS在转录或翻译水平调节关系，明确连接ClpP和SaeS中间分子的作用及调节机制。动物体内模型进一步明确ClpP与SaeS之间调节关系最终对细菌毒力的影响。研究结果将为补充完善蛋白酶ClpP的调控网络、阐明蛋白酶调控细菌毒力的机制、筛选新的抗感染药物靶标提供新思路。

The proteases system have important functions in the quality control of proteins, which are necessary for bacterial homeostasis in Staphylococcus aureus. ATP-dependent protease ClpP is important for stress response, biofilm formation and pathogenesis, but the exact mechanism is still unknown. In the previous study, we found that ClpP regulates the expression of the important virulence regulator SaeS significantly. The expression of SaeS was increased significantly in clpP mutant strain compared to wild-type. More importantly, the SaeS-controlled target genes were also down-regulated by ClpP. How ClpP protease and ATPase chaperons regulate expression of SaeS? Whether the regulatory network between ClpP and SaeS contributes to virulence? In order to identify regulatory network between ClpP and SaeS systemically, we will analyze the regulation relationship between ClpP and SaeS on transcriptional and translational level in detail. We will identify the role and regulatory mechanism of the unknown proteins connecting ClpP and SaeS. Furthermore, we will verify the contribution to virulence by the regulatory network between ClpP and SaeS using mouse model. Our study is significant because it advances our understanding of regulatory network of ClpP protease, it identifies the mechanism of how protease affects virulence and it enables us to design new molecules blocking the staphylococcal survival strategies.