Regulation of narZ gene expression by RcsCDB/RstAB systems in Salmonella Typhimurium

MÓNICA F. TORREZ LAMBERTI; MARÍA DE LAS MERCEDES PESCARETTI; MÓNICA A. DELGADO; FABIAN E. LOPEZ

Mar del Plata

Congreso; LI Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology; 2015

In order to survive at the environmental changes Salmonella Typhimurium is able to utilize specialized mechanisms to control the gene regulation. The RcsCDB system responds to stress conditions and it is involved in the controls of Salmonella virulence. The narZ gene encodes a nitrate reductase and its expression is required to support carbon source starvation and anaerobic growth in Salmonella Typhimurium. The aim of this work was investigated the mechanism implicated in the control of the narZ gene transcription mediated by RcsCDB and its effect in the intestinal lumen establishment. Our results showed that the RcsCDB system controls negatively the narZ transcription. The bioinformatic and gel shift analysis demonstrated that the narZ gene promoter region contains an RcsB-binding site and that this regulator exerts their effect by directly binding to these conserved box. In addition, as was reported that the RstAB system downregulated the narZ expression, we also investigated a putative interaction between the RstAB and RcsCDB systems in the control of the narZ gene transcription, of the bacterial growth under carbon source starvation and anaerobic conditions. In this study we described that the narZ gene expression is modulated by a mechanism in which RcsB and RstA compete by the control of the gene transcription.