Regulation of σ factors by conserved partner switches controlled by divergent signalling systems

Sophie Bouillet (1) , Dallel Arabet (2) , Cecile Jourlin-Castelli (1) , Vincent Méjean (1) , Chantal Iobbi-Nivol (1)

1 BIP - Bioénergétique et Ingénierie des Protéines
2 Université de Constantine

Partner‐Switching Systems (PSS) are widespread regulatory systems, each comprising a kinase‐anti‐σ, a phosphorylatable anti‐σ antagonist and a phosphatase module. The anti‐σ domain quickly sequesters or delivers the target σ factor according to the phosphorylation state of the anti‐σ antagonist induced by environmental signals. The PSS components are proteins alone or merged to other domains probably to adapt to the input signals. PSS are involved in major cellular processes including stress response, sporulation, biofilm formation and pathogenesis. Surprisingly, the target σ factors are often unknown and the sensing modules acting upstream from the PSS diverge according to the bacterial species. Indeed, they belong to either two‐component systems or complex pathways as the stressosome or Chemosensory Systems (CS). Based on a phylogenetic analysis, we propose that the sensing module in Gram‐negative bacteria is often a CS.

Mots clés: Environmental signal and stress responses; gene regulation; anti-sigma factor; 14chemosensory systems; phylogeny

Domaines: Biochimie, Biologie Moléculaire

Sophie Bouillet, Dallel Arabet, Cecile Jourlin-Castelli, Vincent Méjean, Chantal Iobbi-Nivol. Regulation of σ factors by conserved partner switches controlled by divergent signalling systems. Environmental Microbiology Reports, 2018, 10 (2), pp.127 - 139. ⟨10.1111/1758-2229.12620⟩. ⟨hal-01890037⟩