About one quarter of people worldwide are infected with tuberculosis, and multi-drug resistant tuberculosis (MDR-TB) remains a health threat. It is known that two-Component Signal Transduction Systems (TCSs) of Mycobacterium tuberculosis are closely related to tuberculosis resistance, but the mechanism by which orphan response protein Rv3143 regulates strain sensitivity to drug is still unclear. This study found that Rv3143 overexpression resulted in approximately two-fold increase in Mycobacterium smegmatis antibiotic sensitivity. Transcriptome sequencing indicated that 198 potential genes were regulated by Rv3143, affecting the sensitivity of the strain to rifampicin (RIF). MSMEG_4740 promoter binding with Rv3143, was screened out by surface plasmon resonance (SPR). Rv1524, the homologous gene of MSMEG_4740, belonging to the glycosyltransferase (Gtf) family, was related to cell wall modification. By measuring ethidium bromide (EB) accumulation, we found when Rv3143 or MSMEG_4740, or Rv1524 was overexpressed, the cell wall permeability of Mycobacterium smegmatis was increased. In addition, a combination of Rv3143 and RIF was observed. Our findings provide a new strategy for treating drug-resistant tuberculosis by increasing the expression of Rv3143 to enhance the strain sensitivity to antibiotics.

全球约有四分之一的人感染了结核病，耐多药结核病（MDR-TB）仍然是健康威胁。众所周知，结核分枝杆菌的两组分信号转导系统（TCS）与结核耐药性密切相关，但是孤儿应答蛋白Rv3143调节菌株对药物敏感性的机制仍不清楚。这项研究发现Rv3143的过度表达导致耻垢分枝杆菌的含量增加了大约两倍抗生素敏感性。转录组测序表明，Rv3143调节了198个潜在基因，影响了该菌株对利福平（RIF）的敏感性。通过表面等离振子共振（SPR）筛选出与Rv3143结合的MSMEG_4740启动子。Rv1524是MSMEG_4740的同源基因，属于糖基转移酶（Gtf）家族，与细胞壁修饰有关。通过测量溴化乙锭（EB）的积累，我们发现当Rv3143或MSMEG_4740或Rv1524过表达时，耻垢分枝杆菌的细胞壁通透性增加。另外，观察到Rv3143和RIF的组合。我们的发现通过增加Rv3143的表达来增强菌株对抗生素的敏感性，为治疗耐药性结核病提供了新的策略。