title: Motility modulation by the small non-coding RNA SroC in Salmonella Typhimurium.
abstract: Bacterial regulatory networks of gene expression include the interaction of diverse types of molecules such as the small non-coding RNAs (sRNAs) and their cognate messenger RNAs (mRNAs). In this study, we demonstrated that the Salmonella Typhimurium sRNA SroC is significantly expressed between the late-exponential and stationary phase of growth in an rpoS-dependent manner. The expression of flagellar genes predicted as targets of this sRNA was quantitatively analyzed in both a ΔsroC mutant and a SroC-overexpressing (pSroC) strain. Deletion of sroC increased flagellar gene expression (i.e. flhBAE and fliE). Conversely, overexpression of SroC reduced flhBAE and fliE expression. These observations correlated with phenotypic evaluation of motility, where sroC deletion slightly increased motility, which in turn, was drastically reduced upon overexpression of SroC. The effects of deletion and overexpression of sroC in biofilm formation were also examined, where the ΔsroC and pSroC strains exhibited a reduced and increased ability to form biofilm, respectively. Furthermore, electron microscopy revealed that the wild-type strain overexpressing SroC had a non-flagellated phenotype. Taken together, our results showed that S. Typhimurium sRNA SroC modulates the flagellar synthesis by down-regulating the expression of flhBAE and fliE genes.
authors: Laboratorio de Genética y Patogénesis Bacteriana, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors: Danitza N
authors: DN
authors: Fuentes
authors: Laboratorio de Genética y Patogénesis Bacteriana, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile Gut Microbiota and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors: Paulina F
authors: PF
authors: Calderón
authors: Laboratorio de Ecofisiología Microbiana, Fundación Ciencia y Vida, Santiago, Chile.
authors: Lillian G
authors: LG
authors: Acuña
authors: Center for Integrative Medicine and Innovative Sciences, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile.
authors: Paula I
authors: PI
authors: Rodas
authors: Gut Microbiota and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors: Daniel
authors: D
authors: Paredes-Sabja
authors: Laboratorio de Microbiología, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors: Juan A
authors: JA
authors: Fuentes
authors: Laboratorio de Genética y Patogénesis Bacteriana, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors: Fernando
authors: F
authors: Gil
authors: Laboratorio de Genética y Patogénesis Bacteriana, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile lcalderon@unab.cl.
authors: Iván L
authors: IL
authors: Calderón
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D018441:Biofilms / Q000254:growth & development; D005407:Flagella / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008854:Microscopy, Electron; D012333:RNA, Messenger; D058727:RNA, Small Untranslated / Q000235:genetics* / Q000502:physiology*; D012486:Salmonella typhimurium / Q000235:genetics* / Q000254:growth & development* / Q000648:ultrastructure
chemical_list: D001426:Bacterial Proteins; D012333:RNA, Messenger; D058727:RNA, Small Untranslated
keywords: SroC; flagella; flhBAE; fliE; motility; sRNA