title: Roles of RpoS in Yersinia pseudotuberculosis stress survival, motility, biofilm formation and type VI secretion system expression.
abstract: RpoS (σ(S)), the stationary phase/stress σ factor, controls the expression of a large number of genes involved in cellular responses to a variety of stresses. However, the role of RpoS appears to differ in different bacteria. While RpoS is an important regulator of flagellum biosynthesis, it is associated with biofilm development in Edwardsiella tarda. Biofilms are dense communities formed by bacteria and are important for microbe survival under unfavorable conditions. The type VI secretion system (T6SS) discovered recently is reportedly associated with several phenotypes, ranging from biofilm formation to stress sensing. For example, Vibrio anguillarum T6SS was proposed to serve as a sensor for extracytoplasmic signals and modulates RpoS expression and stress response. In this study, we investigated the physiological roles of RpoS in Yersinia pseudotuberculosis, including bacterial survival under stress conditions, flagella formation, biofilm development and T6SS expression. We found that RpoS is important in resistance to multiple stressors-including H2O2, acid, osmotic and heat shock-in Y. pseudotuberculosis. In addition, our study showed that RpoS not only modulates the expression of T6SS but also regulates flagellum formation by positively controlling the flagellar master regulatory gene flhDC, and affects the formation of biofilm on Caenorhabditis elegans by regulating the synthesis of exopolysaccharides. Taken together, these results show that RpoS plays a central role in cell fitness under several adverse conditions in Y. pseudotuberculosis.
authors: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, P. R. China.
authors: Jingyuan
authors: J
authors: Guan
authors: Xiao
authors: X
authors: Xiao
authors: Shengjuan
authors: S
authors: Xu
authors: Fen
authors: F
authors: Gao
authors: Jianbo
authors: J
authors: Wang
authors: Tietao
authors: T
authors: Wang
authors: Yunhong
authors: Y
authors: Song
authors: Junfeng
authors: J
authors: Pan
authors: Xihui
authors: X
authors: Shen
authors: Yao
authors: Y
authors: Wang
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development*; D017173:Caenorhabditis elegans / Q000382:microbiology / Q000648:ultrastructure; D005407:Flagella / Q000235:genetics / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D018869:Heat-Shock Response / Q000235:genetics; D006861:Hydrogen Peroxide / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics* / Q000502:physiology*; D013312:Stress, Physiological / Q000235:genetics / Q000502:physiology; D000069376:Type VI Secretion Systems / Q000235:genetics*; D015011:Yersinia pseudotuberculosis / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor; D000069376:Type VI Secretion Systems; C069567:sigma factor KatF protein, Bacteria; D006861:Hydrogen Peroxide