title: The CsrA-FliW network controls polar localization of the dual-function flagellin mRNA in Campylobacter jejuni.
abstract: The widespread CsrA/RsmA protein regulators repress translation by binding GGA motifs in bacterial mRNAs. CsrA activity is primarily controlled through sequestration by multiple small regulatory RNAs. Here we investigate CsrA activity control in the absence of antagonizing small RNAs by examining the CsrA regulon in the human pathogen Campylobacter jejuni. We use genome-wide co-immunoprecipitation combined with RNA sequencing to show that CsrA primarily binds flagellar mRNAs and identify the major flagellin mRNA (flaA) as the main CsrA target. The flaA mRNA is translationally repressed by CsrA, but it can also titrate CsrA activity. Together with the main C. jejuni CsrA antagonist, the FliW protein, flaA mRNA controls CsrA-mediated post-transcriptional regulation of other flagellar genes. RNA-FISH reveals that flaA mRNA is expressed and localized at the poles of elongating cells. Polar flaA mRNA localization is translation dependent and is post-transcriptionally regulated by the CsrA-FliW network. Overall, our results suggest a role for CsrA-FliW in spatiotemporal control of flagella assembly and localization of a dual-function mRNA.
authors.affiliation: Research Centre for Infectious Diseases (ZINF), University of Würzburg, Josef-Schneider-Str. 2/D15, Würzburg D-97080, Germany.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Dugar
authors.affiliation: Research Centre for Infectious Diseases (ZINF), University of Würzburg, Josef-Schneider-Str. 2/D15, Würzburg D-97080, Germany.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Svensson
authors.affiliation: Research Centre for Infectious Diseases (ZINF), University of Würzburg, Josef-Schneider-Str. 2/D15, Würzburg D-97080, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Bischler
authors.affiliation: Department of Biotechnology and Biophysics, University of Würzburg, Am Hubland, Würzburg D-97074, Germany.
authors.forename: Sina
authors.initials: S
authors.lastname: Wäldchen
authors.affiliation: Max Planck Genome Centre Cologne, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne D-50829, Germany.
authors.forename: Richard
authors.initials: R
authors.lastname: Reinhardt
authors.affiliation: Department of Biotechnology and Biophysics, University of Würzburg, Am Hubland, Würzburg D-97074, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Sauer
authors.affiliation: Research Centre for Infectious Diseases (ZINF), University of Würzburg, Josef-Schneider-Str. 2/D15, Würzburg D-97080, Germany.
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Sharma
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002169:Campylobacter Infections / Q000382:microbiology; D016123:Campylobacter jejuni / Q000235:genetics* / Q000378:metabolism; D005407:Flagella / Q000235:genetics / Q000378:metabolism; D005408:Flagellin / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008957:Models, Genetic; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D012333:RNA, Messenger; D005408:Flagellin; C067138:flaA protein, bacteria