title: Direct regulation by the Vibrio cholerae regulator ToxT to modulate colonization and anticolonization pilus expression.
abstract: The pathogen Vibrio cholerae uses a large number of coordinated transcriptional regulatory events to transition from its environmental reservoir to the host and establish itself at its preferred colonization site at the host intestinal mucosa. The key regulator in this process is the AraC/XylS family transcription factor, ToxT, which plays critical roles in pathogenesis, including the regulation of two type IV pili, the anticolonization factor mannose-sensitive hemagglutinin and the toxin-coregulated pilus. Previously, it was thought ToxT required dimerization in order to effect transcriptional regulation at its cognate promoters. Here, we present evidence that ToxT directly represses transcription of the msh operon by binding to three promoters within this operon and that dimerization may not be required for transcriptional repression of target promoters by ToxT, suggesting that this regulator uses different mechanisms to modulate the transcriptional repertoire of V. cholerae.
authors.affiliation: Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
authors.forename: Ansel
authors.initials: A
authors.lastname: Hsiao
authors.forename: Xiao
authors.initials: X
authors.lastname: Xu
authors.forename: Biao
authors.initials: B
authors.lastname: Kan
authors.forename: Rahul V
authors.initials: RV
authors.lastname: Kulkarni
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002087:Butyrates / Q000494:pharmacology; D003470:Culture Media; D019281:Dimerization; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism; D010861:Fimbriae, Bacterial / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006388:Hemagglutinins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D037601:Mannose-Binding Lectin / Q000235:genetics / Q000378:metabolism; D005810:Multigene Family; D053644:Naphthalimides / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014734:Vibrio cholerae / Q000254:growth & development / Q000472:pathogenicity*; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002087:Butyrates; D003470:Culture Media; D006388:Hemagglutinins; D037601:Mannose-Binding Lectin; C101032:MshA protein, Vibrio cholerae; D053644:Naphthalimides; C085807:TcpA protein, Vibrio cholerae; D014157:Transcription Factors; D037521:Virulence Factors; C505381:virstatin; D036781:Fimbriae Proteins; C075626:tcpN protein, Vibrio cholerae