The General Stress Response σS Is Regulated by a Partner Switch in the Gram-negative Bacterium Shewanella oneidensis

Sophie Bouillet (1) , Olivier Genest (1) , Cecile Jourlin-Castelli (1) , Michel Fons (1) , Vincent Méjean (1) , Chantal Iobbi-Nivol (1)

1 BIP - Bioénergétique et Ingénierie des Protéines

Here, we show that a partner-switching system of the aquatic Proteobacterium Shewanella oneidensis regulates post-translationally σS (also called RpoS), the general stress response sigma factor. Genes SO2118 and SO2119 encode CrsA and CrsR, respectively. CrsR is a three-domain protein comprising a receiver, a phosphatase, and a kinase/anti-sigma domains, and CrsA is an anti-sigma antagonist. In vitro, CrsR sequesters σS and possesses kinase and phosphatase activities toward CrsA. In turn, dephosphorylated CrsA binds the anti-sigma domain of CrsR to allow the release of σS. This study reveals a novel pathway that post-translationally regulates the general stress response sigma factor differently than what was described for other proteobacteria like Escherichia coli. We argue that this pathway allows probably a rapid bacterial adaptation.

Mots clés: bacteria; bacterial protein kinase; bacterial protein phosphatase; protein-protein interaction; stress response

Domaines: Sciences du Vivant [q-bio]

Sophie Bouillet, Olivier Genest, Cecile Jourlin-Castelli, Michel Fons, Vincent Méjean, et al.. The General Stress Response σS Is Regulated by a Partner Switch in the Gram-negative Bacterium Shewanella oneidensis. Journal of Biological Chemistry, 2016, 291, pp 26151-26163. ⟨10.1074/jbc.M116.751933⟩. ⟨hal-01415795⟩