INTERACTION OF RstBA AND RcscDB REGULATORY SYSTEMS FOR CONTROL OF THE Salmonella typhimurium

LÓPEZ FE; GRAMAJO A; CABEZA ML; GARCÍA VÉSCOVI E; MORERO RD; DELGADO MA

Puerto Madryn - Chubut

Congreso; SAIB 2010; 2010

Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular

The two-component regulatory systems are one of the most important mechanisms by which bacteria have managed to survive environmental changes, by modulating the gene expression. The aim of this study was to determine if there is an interaction between the RstBA and RcsCDB regulatory system to control the expression of different genes. This study was based on the observation that RstA (over-production only) negatively regulates csgD, whose product modulates those genes required for cell-cell interactions and their environment, like bapA. On the other hand, the csgD gene is positively regulated by RpoS, which in turn is repressed by RstA and induced by RcsB. This led us to think that RstBA and RcsCDB systems may be interacting in order to control genes, especially those required by Salmonella to establish systemic infection. In this work we investigated the effect of overexpression of RcsB on gene fusions controlled by RstA, such as asr, narZ and spvA. Our results indicate that RcsB and RstA competitively inhibit the narZ and spvA genes transcription. Furthermore, RcsB represses asr expression by inhibiting the rstA transcription