The serine proteases of Mycobacteria tuberculosis(Mtb)are important contributors to the process of bacterial invasion and its pathogenesis.In the present study,we systematically characterized the role of the Rv1043c p...The serine proteases of Mycobacteria tuberculosis(Mtb)are important contributors to the process of bacterial invasion and its pathogenesis.In the present study,we systematically characterized the role of the Rv1043c protein in Mycobacterium infection by purifying the Rv1043c protein in Escherichia coli and constructing a Mycobacterium smegmatis(Msg)strain overexpressing Rv1043c(Msg_Rv1043c).We found that Rv1043c had serine protease activity and localized to the surface of Mtb.We determined that the optimal pH and temperature for the Rv1043c serine protease were 9.0 and 45°C,respectively.Moreover,the serine protease activity of Rv1043c was enhanced by divalent metal ions of Ca^(2+)and Mg^(2+).Site-directed mutagenesis studies demonstrated that the serine 279 residue in Rv1043c plays a catalytic role.Additionally,mouse model studies confirmed that Rv1043c significantly enhanced the survival of Msg in vivo,induced pulmonary injury and lung cell apoptosis,and promoted the release of pro-inflammatory cytokines interleukin-1βand interleukin-6 in mice.This study presents novel insights into the relationship between mycobacterial serine protease and the pathogenesis of the disease.展开更多
基金This research was supported by the National Key Research and Development Program of China(2021YFD1800403)the National Natural Science Foundation of China(32273005 and 32002256).
文摘The serine proteases of Mycobacteria tuberculosis(Mtb)are important contributors to the process of bacterial invasion and its pathogenesis.In the present study,we systematically characterized the role of the Rv1043c protein in Mycobacterium infection by purifying the Rv1043c protein in Escherichia coli and constructing a Mycobacterium smegmatis(Msg)strain overexpressing Rv1043c(Msg_Rv1043c).We found that Rv1043c had serine protease activity and localized to the surface of Mtb.We determined that the optimal pH and temperature for the Rv1043c serine protease were 9.0 and 45°C,respectively.Moreover,the serine protease activity of Rv1043c was enhanced by divalent metal ions of Ca^(2+)and Mg^(2+).Site-directed mutagenesis studies demonstrated that the serine 279 residue in Rv1043c plays a catalytic role.Additionally,mouse model studies confirmed that Rv1043c significantly enhanced the survival of Msg in vivo,induced pulmonary injury and lung cell apoptosis,and promoted the release of pro-inflammatory cytokines interleukin-1βand interleukin-6 in mice.This study presents novel insights into the relationship between mycobacterial serine protease and the pathogenesis of the disease.
