title: Dual role of RsmA in the coordinated regulation of expression of virulence genes in Pectobacterium wasabiae strain SCC3193.
abstract: The CsrA/RsmA family of post-transcriptional regulators in bacteria is involved in regulating many cellular processes, including pathogenesis. Using a bioinformatics approach, we identified an RsmA binding motif, A(N)GGA, in the Shine-Dalgarno regions of 901 genes. Among these genes with the predicted RsmA binding motif, 358 were regulated by RsmA according to our previously published gene expression profiling analysis (WT vs rsmA negative mutant; Kõiv et al., 2013). A small subset of the predicted targets known to be important as virulence factors was selected for experimental validation. RNA footprint analyses demonstrated that RsmA binds specifically to the ANGGA motif in the 5'UTR sequences of celV1, pehA, pelB, pel2 and prtW. RsmA-dependent regulation of these five genes was examined in vivo using plasmid-borne translational and transcriptional fusions with a reporter gusA gene. They were all affected negatively by RsmA. However, we demonstrated that whereas the overall effect of RsmA on celV1 and prtW was determined on both the translational and transcriptional level, expression of pectinolytic enzyme genes (pehA, pel2 and pelB) was affected mainly on the level of transcription in tested conditions. In summary, these data indicate that RsmA controls virulence by integration of its regulatory activities at various levels.
authors: Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Estonia.
authors: Liis
authors: L
authors: Andresen
authors: Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Estonia.
authors: Jekaterina
authors: J
authors: Frolova
authors: Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Estonia.
authors: Lee
authors: L
authors: Põllumaa
authors: Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Estonia.
authors: Andres
authors: A
authors: Mäe
mesh_terms: D001665:Binding Sites; D019295:Computational Biology; D004269:DNA, Bacterial / Q000235:genetics; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D044043:Pectobacterium / Q000235:genetics* / Q000378:metabolism*; D011485:Protein Binding; D016601:RNA-Binding Proteins / Q000378:metabolism*; D037521:Virulence Factors / Q000096:biosynthesis*
chemical_list: D004269:DNA, Bacterial; D016601:RNA-Binding Proteins; D037521:Virulence Factors