BIOINFORMATICS ANALYSIS OF THE RCSCDB SYSTEM

FARIZANO JV; MARIA DE LAS MERCEDES PESCARETTI; LOPEZ, FE; DELGADO MA

Potrero de Funes, San Luis

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2011

Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular

The Rcs phosphorelay system, involved in the control of Salmonellavirulence, is a complex regulatory system that consists in three proteins: the RcsC sensor, the RcsB response regulator and the phosphorelation intermediary RcsD. Even when the signal remains unknown, several conditions have been characterized by the ability to activate it. The RcsCDB controls the expression of a wide range of genes, which can be divided according to their dependency on the RcsA co-activator. RcsA-dependent genes include the cps operon and the rcsA gene, while the RcsA-independent genes consist of different targets including the ftsA and fhlDC genes, and those involved in motility and chemotaxis. Here we analyzed a microarray assay carried out under RcsCDB system activation. We classified the genes according to the effect exerted by RcsB and RcsA, in up or down-regulated and RcsA-dependent or –independent clusters, respectively. We found that 143 of 304 analyzed genes were down-regulated by RcsB while 161 were up-regulated. In this assays only 29 genes were expressed in an RcsA-dependent pathway, all were included in the RcsB up-regulated cluster. In addition, the microarrays results were validated by the analysis of the osmY gene expression, involved in the stress response. To this end we cloned the promoter region in a promoter expression vector and we performed gel shift assay.