结核分枝杆菌Rv1273 c-Rv1272 c转运功能的初步研究

摘要

Objective To investigate the functions of Rv1273c and Rv1272c, two ATP-binding cassette transporters (ABC transporters) in Mycobacterium tuberculosis (M. tuberculosis). Methods The ethidium bromide ( EB)-agar cartwheel and EB accumulation assays were used to detect the transport direc-tion of Rv1273c and Rv1272c in the recombinant strains of BL21/pET-28a-rv1273c and BL21/pET-28a-rv1272c, which were constructed by our lab in the previous study. RT-PCR was used to confirm whether rv1273c and rv1272c genes were in the same operon. Real-time PCR was performed to detect the expression of rv1272c and rv1273c genes in M. tuberculosis strains of H37Rv and H37Ra. Results Both the EB-agar cartwheel and the EB accumulation assays indicated that Rv1273c and Rv1272c transported EB into cells. Results of the RT-PCR showed that rv1273c and rv1272c were in the same operon. The expression of rv1273c and rv1272c at mRNA level in M. tuberculosis H37Ra strain were about 6 times higher than those in M. tuber-culosis H37Rv strain. Conclusion Rv1273c and Rv1272c are ABC importers and might be related to the virulence of M. tuberculosis.%目的：研究结核分枝杆菌ATP结合盒( ATPbinding cassette,ABC)转运蛋白Rv1273c-Rv1272c的转运功能。方法以本实验室前期构建的 BL21/pET-28a-rv1273c 和 BL21/pET-28a-rv1272c重组大肠埃希菌为研究对象,采用溴化乙锭( EB)琼脂试验及EB吸收试验研究Rv1273c和Rv1272c的物质转运方向；通过逆转录PCR的方法确认rv1273c和rv1272c是否位于同一个转录单位,并且通过real-time PCR的方法比较结核分枝杆菌标准株H37Rv和H37Ra中rv1272c和rv1273c的表达差异,验证其与结核分枝杆菌毒力的相关性。结果 EB琼脂试验及EB吸收试验均表明Rv1273c和Rv1272c能够向胞内转运EB；rv1273c与rv1272c位于同一个转录单位,且其在H37Ra中的表达均约是H37Rv的6倍。结论 Rv1273c和Rv1272c为内向转运蛋白,组成一个多顺反子,可能与结核分枝杆菌的毒力相关。