title: The Vibrio cholerae VarS/VarA two-component system controls the expression of virulence proteins through ToxT regulation.
abstract: Although the conditions for inducing virulence protein expression in vitro are different, both classical and El Tor biotypes of Vibrio cholerae have been reported to regulate the expression of virulence proteins such as cholera toxin (CT) and toxin-coregulated pili (Tcp) through the ToxR/S/T system. The transcription activator ToxR responds to environmental stimuli such as pH and temperature and activates the second transcriptional regulator ToxT, which upregulates expression of virulence proteins. In addition to the ToxR/S/T signalling system, V. cholerae has been proposed to utilize another two-component system VarS/VarA to modulate expression of virulence genes. Previous study has shown that VarA of the VarS/VarA system is involved in the regulation of virulence proteins in the classical V. cholerae O395 strain; however, no further analysis was performed concerning VarS. In this study, we constructed varS mutants derived from the classical O395 and El Tor C6706 strains and demonstrated that VarS is also involved in the expression of the virulence proteins CT and Tcp from the V. cholerae classical and El Tor strains. This expression is through regulation of ToxT expression in response to environmental changes due to different toxin-inducing conditions.
authors.affiliation: Division of High-Risk Pathogen Research, Center for Infectious Diseases, National Institute of Health, 187 Osongsaengmyeong2-ro, Cheongwon-gun, Chungbuk 363-951, Republic of Korea.
authors.forename: Jeyoun
authors.initials: J
authors.lastname: Jang
authors.affiliation: Division of High-Risk Pathogen Research, Center for Infectious Diseases, National Institute of Health, 187 Osongsaengmyeong2-ro, Cheongwon-gun, Chungbuk 363-951, Republic of Korea.
authors.forename: Kyung-Tae
authors.initials: KT
authors.lastname: Jung
authors.affiliation: Protein Research Center for Bioindustry, Hankuk University of Foreign Studies, Yongin 449-791, Republic of Korea.|Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yongin 449-791, Republic of Korea.
authors.forename: Jungchan
authors.initials: J
authors.lastname: Park
authors.affiliation: Division of High-Risk Pathogen Research, Center for Infectious Diseases, National Institute of Health, 187 Osongsaengmyeong2-ro, Cheongwon-gun, Chungbuk 363-951, Republic of Korea.
authors.forename: Cheon-Kwon
authors.initials: CK
authors.lastname: Yoo
authors.affiliation: Division of High-Risk Pathogen Research, Center for Infectious Diseases, National Institute of Health, 187 Osongsaengmyeong2-ro, Cheongwon-gun, Chungbuk 363-951, Republic of Korea.
authors.forename: Gi-Eun
authors.initials: GE
authors.lastname: Rhie
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002771:Cholera / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014734:Vibrio cholerae / Q000235:genetics / Q000378:metabolism*; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; C091100:GacA protein, Bacteria; D047908:Intracellular Signaling Peptides and Proteins; D014157:Transcription Factors; D037521:Virulence Factors; C075626:tcpN protein, Vibrio cholerae; D011494:Protein Kinases; C560406:VarS protein, Vibrio cholerae