title: Identification of the Vibrio parahaemolyticus type III secretion system 2-associated chaperone VocC for the T3SS2-specific effector VopC.
abstract: The enteropathogen Vibrio parahaemolyticus possesses two sets of type III secretion systems, T3SS1 and T3SS2. Effector proteins secreted by these T3SSs are delivered into host cells, leading to cell death or diarrhea. However, it is not known how specific effectors are secreted through a specific T3SS when both T3SSs are expressed within bacteria. One molecule thought to determine secretion specificity is a T3SS-associated chaperone; however, no T3SS2-specific chaperone has been identified. Therefore, we screened T3SS2 chaperone candidates by a pull-down assay using T3SS2 effectors fused with glutathione-S-transferase. A secretion assay revealed that the newly identified cognate chaperone VocC for the T3SS2-specific effector VopC was required for the efficient secretion of the substrate through T3SS2. Further experiments determined the chaperone-binding domain and the amino-terminal secretion signal of the cognate effector. These findings, in addition to the previously identified T3SS1-specific chaperone, VecA, provide a strategy to clarify the specificity of effector secretion through T3SSs of V. parahaemolyticus.
authors.affiliation: Department of Bacterial Infections, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan. akeda@biken.osaka-u.ac.jp
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Akeda
authors.forename: Toshio
authors.initials: T
authors.lastname: Kodama
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Saito
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Iida
authors.forename: Kazunori
authors.initials: K
authors.lastname: Oishi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Honda
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D058947:Bacterial Secretion Systems; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D014735:Vibrio Infections / Q000382:microbiology*; D014736:Vibrio parahaemolyticus / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D018832:Molecular Chaperones