A Two-Component System that Modulates Cyclic-di-GMP Metabolism PromotesLegionella pneumophilaDifferentiation and Viability in Low-Nutrient Conditions

• DOI: 10.1101/604611
• Publication Date: 2019-04-11T19:06:33Z
• Authors: Elisa D. Hughes; Brenda G. Byrne; Michele S. Swanson
• Keywords: rpoS; Response regulator; Wild type

ABSTRACT During its life cycle, the environmental pathogen Legionella pneumophila alternates between a replicative and transmissive cell type when cultured in broth, macrophages, or amoebae. Within protozoan host, L. further differentiates into hardy known as Mature Infectious Form (MIF). The second messenger cyclic-di-GMP coordinates lifestyle changes many bacterial species, but role cycle is less understood. Using an vitro broth culture model that approximates intracellular transition from to form, here we investigate contribution differentiation of two-component system (TCS) regulates metabolism. TCS encoded by lpg0278-lpg0277 co-transcribed with lpg0279 , which encodes protein upregulated MIF cells. gfp -reporter, demonstrate promoter for this operon RpoS-dependent induced nutrient-limiting conditions do not support replication. response regulator (Lpg0277) bifunctional enzyme both synthesizes degrades cyclic-di-GMP. panel site-directed point mutants, show synthesis mediated conserved GGDEF domain promotes growth arrest production pigment poly-3-hydroxybutyrate storage granules, viability conditions. Genetic epistasis tests predict Lpg0279 acts upstream negative regulator. Thus, equipped regulatory network stimulates switch resilient state survive low-nutrient environments. IMPORTANCE Although pathogen, has developed mechanisms ensure long-term survival aqueous Eradication contaminated water supplies proven challenging, outbreaks have been traced previously remediated systems. Understanding genetic determinants persistence environments can inform design remediation methods. Here characterize locus signaling ( ) putative modulates molecule We conditions, thus advancing our understanding contribute resilience.