title: Hfq and Hfq-dependent small RNAs are major contributors to multicellular development in Salmonella enterica serovar Typhimurium.
abstract: The RNA chaperone Hfq and its associated small RNAs (sRNAs) regulate a variety of phenotypes in bacteria. In this work, we show that Hfq is a master regulator of biofilm formation in Salmonella enterica serovar Typhimurium. Hfq and two Hfq-dependent sRNAs (ArcZ and SdsR) are required for rdar morphotype expression in S. typhimurium. Hfq controls rdar biofilm formation through the major biofilm regulator CsgD. While csgD mRNA steady-state levels are altered in a sdsR mutant, ArcZ seems to work mainly at the post-transcriptional level. Overexpression of ArcZ complemented rdar morphotype formation of an hfq mutant under plate-grown conditions. Although ArcZ activates rpoS expression, its effect on csgD expression is mainly independent of RpoS. ArcZ does not only regulate rdar morphotype expression, but also the transition between sessility and motility and the timing of type 1 fimbriae vs. curli fimbriae surface-attachment at ambient temperature. Consequently, ArcZ is a major regulator of rdar biofilm development.
authors.affiliation: Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden.
authors.forename: Claudia
authors.initials: C
authors.lastname: Monteiro
authors.forename: Kai
authors.initials: K
authors.lastname: Papenfort
authors.forename: Karina
authors.initials: K
authors.lastname: Hentrich
authors.forename: Irfan
authors.initials: I
authors.lastname: Ahmad
authors.forename: Soazig
authors.initials: S
authors.lastname: Le Guyon
authors.forename: Romy
authors.initials: R
authors.lastname: Reimann
authors.forename: Nina
authors.initials: N
authors.lastname: Grantcharova
authors.forename: Ute
authors.initials: U
authors.lastname: Römling
mesh_terms: D020121:5' Untranslated Regions; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018441:Biofilms; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010641:Phenotype; D058727:RNA, Small Untranslated; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D020121:5' Untranslated Regions; D001426:Bacterial Proteins; D018832:Molecular Chaperones; D058727:RNA, Small Untranslated