ESAT-6是结核菌的毒力因子，由ESX-1系统分泌到体外，但ESAT-6的跨膜运输机制仍然未知。序列分析表明Rv1057编码β-螺旋蛋白，可能是结核菌的外膜运输蛋白。我们的前期研究结果提示Rv1057可能参与ESAT-6分泌，因此，我们假设Rv1057可能是ESX-1系统的新成员，参与ESAT-6的外膜运输。本研究拟：（1）构建Rv1057基因突变菌株，明确Rv1057在ESAT-6分泌中的作用；（2）定位Rv1057在细胞中的位置，分析Rv1057与结核菌组分、相关蛋白之间的相互作用；（3）分析Rv1057的调控因子及其结合位点，通过MTB感染巨噬细胞实验明确这些调控因子对Rv1057表达、ESAT-6分泌和菌株毒性的协同调控作用。此项研究将最终阐明Rv1057是否是ESX-1的成员及其作用机制。研究结果有助于揭示完整的ESAT-6分泌机制，为开发新型结核病重组疫苗提供理论依据。

ESAT-6 is a virulence factor secreted by ESX-1 secretion system in Mycobacterium tuberculosis (MTB), but it is still unclear how ESAT-6 to across the outer membrane. Rv1057 encodes a putative β-propeller protein, which might function as a transport protein. Our preliminary studies imply that Rv1057 might be involved in the secretion of ESAT-6. So we hypotheses that Rv1057 may be a new member of ESX-1 system, and is responsible for outer membrane transportation of ESAT-6. In this study, we will first generate a Rv1057 mutant strain, thereby determine its role in EAST-6 secretion; Next the location of Rv1057, the interaction of Rv1057 with the other relative protein and cell components would be investigated; Then, the regulators and their binding sites on Rv1057 will be analyzed, macrophage model with MTB infection would be performed to clarify the integrated regulation of expression of Rv1057, secretion of ESAT-6 and the virulence of MTB by these regulators. This study will be helpful to reveal the complete secretion mechanism of ESX-1 and provide a theoretical basis for new recombinant vaccine development.