title: The hydrophilic translocator for Vibrio parahaemolyticus, T3SS2, is also translocated.
abstract: The pathogenesis of the diarrheal disease caused by Vibrio parahaemolyticus, a leading cause of seafood-associated enteritis worldwide, is dependent upon a type III secretion system, T3SS2. This apparatus enables the pathogen to inject bacterial proteins (effectors) into the cytosol of host cells and thereby modulate host processes. T3SS effector proteins transit into the host cell via a membrane pore (translocon) typically formed by 3 bacterial proteins. We have identified the third translocon protein for T3SS2: VopW, which was previously classified as an effector protein for a homologous T3SS in V. cholerae. VopW is a hydrophilic translocon protein; like other such proteins, it is not inserted into the host cell membrane but is required for insertion of the two hydrophobic translocators, VopB2 and VopD2, that constitute the membrane channel. VopW is not required for secretion of T3SS2 effectors into the bacterial culture medium; however, it is essential for transfer of these proteins into the host cell cytoplasm. Consequently, deletion of vopW abrogates the virulence of V. parahaemolyticus in several animal models of diarrheal disease. Unlike previously described hydrophilic translocators, VopW is itself translocated into the host cell cytoplasm, raising the possibility that it functions as both a translocator and an effector.
authors.affiliation: Brigham and Women's Hospital/Harvard Medical School and HHMI, Boston, Massachusetts, USA.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhou
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Ritchie
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Hiyoshi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Iida
authors.forename: Brigid M
authors.initials: BM
authors.lastname: Davis
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Waldor
authors.forename: Toshio
authors.initials: T
authors.lastname: Kodama
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018938:Caco-2 Cells; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D006801:Humans; D007082:Ileum / Q000382:microbiology / Q000473:pathology; D005810:Multigene Family; D021381:Protein Transport; D011817:Rabbits; D014735:Vibrio Infections / Q000276:immunology / Q000382:microbiology; D014736:Vibrio parahaemolyticus / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins