Vibrio vulnificus rpoS expression is repressed by direct binding of cAMP-cAMP receptor protein complex to its two promoter regions.

ABSTRACT: Vibrio vulnificus, a septicemia-causing pathogenic bacterium, acquires resistance against various stresses and expresses virulence factors via an rpoS gene product. In this study, we investigated the transcriptional characteristics of this global regulator. Two distinct transcriptional initiation sites for the rpoS gene, the proximal promoter (P(p)) and the distal promoter (P(d)), were defined by primer extension experiments. Various rpoS::luxAB transcriptional fusions indicated that P(d) is a major promoter of rpoS expression. Western blot analysis showed that RpoS levels were inversely correlated with intracellular levels of 3',5'-cyclic AMP (cAMP). The expressions of both P(d) and P(p) were increased in cya and crp mutants. The exogenous addition of cAMP to the cya mutant resulted in re

SUBMITTER: Lee HJ 

PROVIDER: S-EPMC2662139 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature