文摘
The activity of the promoter regions of the cell division genes ftsZ, ftsE, minC, minD and minE from Neisseria gonorrhoeae (Ng) was studied under different environmental conditions using lacZ translational fusions. The promoters of the minNg genes have not been previously determined and we identified promoter regions upstream of each gene (minCp, minDp and minEp). We determined that minDp had the strongest activity. Expression of the promoter regions of ftsZNg and ftsENg, which we had previously identified, as well as minDNg, were then studied under conditions reflecting the environment of the genitourinary tract. These conditions included anaerobiosis, presence of isoleucine or urea (3 mM and 400 mM, respectively) and acidity of pH 6. Both β-galactosidase expression and northern blot analysis indicated that all three genes were upregulated under anaerobiosis. The addition of isoleucine as well as media at pH 6 did not have any significant effects on the promoter activity of these genes while the presence of urea significantly decreased ftsZNg promoter activity. The expression of the minDNg promoter region was analyzed during different growth phases and shown to follow the growth behavior of the culture. By contrast, the ftsZNg promoter activity continued to rise after the onset of the stationary phase. When gonococcal ftsZ promoter 1 (Pz1) was altered by site-directed mutagenesis, a significant decrease in the expression of ftsZNg was observed under both aerobic and anaerobic conditions. These data infer that gonococci regulate their cell division in response to different environments.