The Transcriptional Regulator VqmA Increases Expression of the Quorum-Sensing Activator HapR in Vibrio cholerae

摘要: Vibrio cholerae is the causative agent of severe diarrheal disease cholera. A number environmental stimuli regulate virulence gene expression in V. cholerae, including quorum-sensing signals. At high cell densities, quorum sensing invokes a series signal transduction pathways order to activate master regulator HapR, which then represses regulon and biofilm-related genes activates protease production. In this study, we identified transcriptional regulator, VqmA (VCA1078), that hapR at low densities. Under vitro inducing conditions, constitutive HapR-dependent manner. increases transcription as measured by activity hapR-lacZ reporter, it HapR production Western blotting. Using heterogenous luxCDABE cosmid, found stimulates regulation lower densities stimulation bypasses known LuxO-small-RNA regulatory circuits. Furthermore, showed regulates directly binding its promoter region vqmA density dependent autoregulated. The physiological role also discussed.