结核分枝杆菌的TetR转录因子与Rel蛋白之间的相互作用及其调控细菌生长的分子机制研究

The long term dormancy of Mycobacterium tuberculosis(MTB) in host is closely related to the stringent response mediated by a signaling molecule (p)ppGpp (synthesized and hydrolyzed by RelMtb). However, little is known about the synthesis or hydrolysis regulation of the signaling molecule and its effects on mycobacteria growth. To address the issues, based on the previous work in our lab, we will systematically characterize an interaction between a TetR-like transcriptional regulator Rv3066 and RelMtb, and further investigate their effects on the regulation of MTB growth and drug tolerance. First，we will identify the physically interaction between these two proteins through SPR, Co-IP and fluorescent co-localization assays et al. Then, we will further investigate the effects of the interaction to the synthesis or hydrolysis (p)ppGpp activity of RelMtb and the regulation of the DNA binding activity of Rv3066. Ultimately, through construction of recombination strains, we will compare the differences of the growth and drug tolerance between RelMtb overexpression strain and RelMtb-Rv3066 co-expression strain. The research will contribute to find a new regulatory mechanism of stringent response in MTB and provide new insights into the prevention and controlling of tuberculosis, having important theoretical value and potential practical significance.

结核分枝杆菌（MTB）在宿主中的长期潜伏与(p)ppGpp信号分子(由RelMtb合成与水解)介导的严紧反应密切相关。然而，有关该信号分子的合成或水解调控及其对分枝杆菌生长的影响还鲜有报道。针对这一科学问题，本项目基于实验室已有的工作，系统研究一个TetR家族的转录因子Rv3066与RelMtb之间的相互作用，并探讨它们对MTB生长和耐药性的调控影响。首先，采用SPR、Co-IP和荧光共定位等技术鉴定两者之间的物理相互作用。然后，进一步研究这种蛋白相互作用对RelMtb合成或水解(p)ppGpp活性的影响，以及对Rv3066 的DNA结合活性的调控影响。最后，通过构建重组菌株，比较RelMtb超表达菌株及与Rv3066共表达菌株的生长和耐药性差异等。本项目研究将有助于发现MTB严紧反应调控新机制和为结核病的防控提供新思路，具有重要的理论价值和潜在实际意义。