%0 Journal Article
%T The phosphorelay BarA/SirA activates the non-cognate regulator RcsB in Salmonella enterica
%A Eduardo A. Groisman
%A Hubert Salvail
%J -
%D 2020
%R 10.1371/journal.pgen.1008722
%X To survive an environmental stress, organisms must detect the stress and mount an appropriate response. One way that bacteria do so is by phosphorelay systems that respond to a stress by activating a regulator that modifies gene expression. To ensure an appropriate response, a given regulator is typically activated solely by its cognate phosphorelay protein(s). However, we now report that the regulator RcsB is activated by both cognate and non-cognate phosphorelay proteins, depending on the condition experienced by the bacterium Salmonella enterica serovar Typhimurium. The RcsC and RcsD proteins form a phosphorelay that activates their cognate regulator RcsB in response to outer membrane stress and cell wall perturbations, conditions Salmonella experiences during infection. Surprisingly, the non-cognate phosphorelay protein BarA activates RcsB during logarithmic growth in Luria-Bertani medium in three ways. That is, BarA¡¯s cognate regulator SirA promotes transcription of the rcsDB operon; the SirA-dependent regulatory RNAs CsrB and CsrC further increase RcsB-activated gene transcription; and BarA activates RcsB independently of the RcsC, RcsD, and SirA proteins. Activation of a regulator by multiple sensors broadens the spectrum of environments in which a set of genes is expressed without evolving binding sites for different regulators at each of these genes
%K Isomorphous replacement
%K Salmonella
%K Regulator genes
%K Plasmid construction
%K Phosphorylation
%K Outer membrane proteins
%K Prisms
%K Gene expression
%U https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1008722