title: The small RNA Spot 42 regulates the expression of the type III secretion system 1 (T3SS1) chaperone protein VP1682 in Vibrio parahaemolyticus.
abstract: The cytotoxicity of Vibrio parahaemolyticus has been related to the type III secretion system 1 effector protein VP1680, which is secreted and translocated into host cells with the help of the specific chaperone protein, VP1682. This study sought to confirm the in silico analysis, which predicted that a small regulatory RNA (Spot 42) could base pair with the region encompassing the ribosomal-binding site and initiation codon of the vp1682 mRNA. Electrophoresis mobility shift assays indicated that Spot 42 could bind to the vp1682 mRNA with the help of Hfq. Consistent with these results, the translation of the vp1682 mRNA was inhibited when both Hfq and Spot 42 were added to the in vitro translation reaction. The cytotoxic activity against infected Caco-2 cells was significantly increased in the Spot 42 deletion mutant (Δspf) at 4 h after infection as compared with the parental strain. Additionally, we observed that both VP1682 and VP1680 were more highly expressed in Δspf mutants than in the parental strain. These results indicate that Spot 42 post-transcriptionally regulates the expression of VP1682 in V. parahaemolyticus, which contributes to cytotoxicity in vivo.
authors.affiliation: Laboratory of Hygienic Chemistry, College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime, Japan ttanabe@cc.matsuyama-u.ac.jp.
authors.forename: Tomotaka
authors.initials: T
authors.lastname: Tanabe
authors.affiliation: Department of Microbiology, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, Japan.
authors.forename: Katsushiro
authors.initials: K
authors.lastname: Miyamoto
authors.affiliation: Department of Microbiology, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsujibo
authors.affiliation: Laboratory of Hygienic Chemistry, College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yamamoto
authors.affiliation: Laboratory of Hygienic Chemistry, College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Funahashi
mesh_terms: D018938:Caco-2 Cells; D024202:Electrophoretic Mobility Shift Assay; D015964:Gene Expression Regulation, Bacterial; D035001:Host Factor 1 Protein / Q000235:genetics / Q000378:metabolism; D006801:Humans; D018832:Molecular Chaperones / Q000235:genetics* / Q000378:metabolism; D021381:Protein Transport / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D058727:RNA, Small Untranslated / Q000235:genetics* / Q000378:metabolism*; D017384:Sequence Deletion; D000069296:Type III Secretion Systems / Q000737:chemistry* / Q000235:genetics*; D014736:Vibrio parahaemolyticus / Q000235:genetics* / Q000378:metabolism*
chemical_list: D035001:Host Factor 1 Protein; D018832:Molecular Chaperones; D012333:RNA, Messenger; D058727:RNA, Small Untranslated; D000069296:Type III Secretion Systems
keywords: Spot 42; Vibrio parahaemolyticus; chaperone; effector; small RNA; type III secretion system