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

TORRES LAMBERTI, MF; PESCARETTI MM,; DELGADO MA; LOPEZ, FE

Mar del PLata

Congreso; 51th Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2015

SAIB

REGULATION OF NarZ GENE EXPRESSION BY RcsCDB/RstAB SYSTEMS INSalmonella typhimuriumTorrez Lamberti, MF; Pescaretti, MM; Delgado, MA; López, FE.INSIBIO (CONICET-UNT) and Instituto de Química Biológica ?Dr. Bernabe Bloj? (UNT). Tucumán-Argentina.E-mail: mftorrezlamberti@fbqf.unt.edu.arIn order to survive at the environmental changes Salmonella Typhimurium is able to utilize specialized mechanismsto control the gene regulation. The RcsCDB system responds to stress conditions and it is involved in the controls ofSalmonella virulence. The narZ gene encodes a nitrate reductase and its expression is required to support carbonsource starvation and anaerobic growth in Salmonella typhimurium. The aim of this work was investigated themechanism implicated in the control of the narZ gene transcription mediated by RcsCDB and its effect in theintestinal lumen establishment. Our results showed that the RcsCDB system controls negatively the narZtranscription. The bioinformatic and gel shift analysis demonstrated that the narZ gene promoter region contains anRcsB-binding site and that this regulator exerts their effect by directly binding to this conserved box. In addition, wasreported that the RstAB system down regulated the narZ expression. According this, we also investigated a putativeinteraction between the RstAB and RcsCDB systems in the control of the narZ gene transcription, under the bacterialgrowth in carbon source starvation and anaerobic conditions. In this study we described that the narZ gene expressionis modulated by a mechanism in which RcsB and RstA compete by the control of the gene transcription.