{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T07:14:06Z","timestamp":1771485246455,"version":"3.50.1"},"reference-count":47,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T00:00:00Z","timestamp":1771459200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:p>\n                    The AraC-type transcriptional activator ToxT is a central regulator of\n                    <jats:italic>Vibrio cholerae<\/jats:italic>\n                    virulence, directly controlling expression of the major virulence genes\n                    <jats:italic>ctxAB<\/jats:italic>\n                    and\n                    <jats:italic>tcpA<\/jats:italic>\n                    . Although biotype-specific culture conditions have been widely used to study virulence gene regulation, virulence gene expression patterns are not conserved across\n                    <jats:italic>V. cholerae<\/jats:italic>\n                    strains, particularly within the El Tor biotype. In this study, we investigated strain- and allele-dependent control of\n                    <jats:italic>toxT<\/jats:italic>\n                    expression using isogenic derivatives harboring chromosomally encoded His-tagged\n                    <jats:italic>toxT<\/jats:italic>\n                    alleles, enabling direct comparison of\n                    <jats:italic>toxT<\/jats:italic>\n                    transcription, ToxT protein production, and downstream virulence gene activation. All\n                    <jats:italic>toxT<\/jats:italic>\n                    alleles retained transcriptional activator function once expressed; in the classical biotype strain O395, four different\n                    <jats:italic>toxT<\/jats:italic>\n                    alleles activated virulence gene expression, although the expression levels of\n                    <jats:italic>tcpA<\/jats:italic>\n                    and\n                    <jats:italic>ctxAB<\/jats:italic>\n                    varied among alleles. In contrast, in the El Tor prototype strain N16961,\n                    <jats:italic>toxT<\/jats:italic>\n                    -AY and\n                    <jats:italic>toxT<\/jats:italic>\n                    -AF supported virulence gene expression at 30\u00b0C, whereas\n                    <jats:italic>toxT<\/jats:italic>\n                    -SY and\n                    <jats:italic>toxT<\/jats:italic>\n                    -SF were transcriptionally repressed. By comparison, the atypical El Tor strain IB5230 exhibited robust expression of\n                    <jats:italic>toxT<\/jats:italic>\n                    -SY and\n                    <jats:italic>toxT<\/jats:italic>\n                    -SF, with activation of downstream virulence genes even at 37\u00b0C, a temperature relevant to the intestinal environment. Together, these results demonstrate that\n                    <jats:italic>toxT<\/jats:italic>\n                    expression functions as a regulatory gate within the canonical ToxR regulon and represents a critical control point governing strain-specific virulence gene regulation and pathogenic potential in\n                    <jats:italic>V. cholerae<\/jats:italic>\n                    .\n                  <\/jats:p>","DOI":"10.3389\/fmicb.2026.1755947","type":"journal-article","created":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T06:42:35Z","timestamp":1771483355000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Strain-dependent toxT expression, rather than ToxT activity, governs virulence gene regulation in Vibrio cholerae"],"prefix":"10.3389","volume":"17","author":[{"given":"Jayun","family":"Joo","sequence":"first","affiliation":[{"name":"Department of Pharmacy, College of Pharmacy, Hanyang University","place":["Ansan, Republic of Korea"]},{"name":"Institute of Pharmacological Research, Hanyang University","place":["Ansan, Republic of Korea"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Donghyun","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, College of Pharmacy, Hanyang University","place":["Ansan, Republic of Korea"]},{"name":"Institute of Pharmacological Research, Hanyang University","place":["Ansan, Republic of Korea"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Seoyun","family":"Choi","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, College of Pharmacy, Hanyang University","place":["Ansan, Republic of Korea"]},{"name":"Institute of Pharmacological Research, Hanyang University","place":["Ansan, Republic of Korea"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hyungoo","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, College of Pharmacy, Hanyang University","place":["Ansan, Republic of Korea"]},{"name":"Institute of Pharmacological Research, Hanyang University","place":["Ansan, Republic of Korea"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dong Wook","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, College of Pharmacy, Hanyang University","place":["Ansan, Republic of Korea"]},{"name":"Institute of Pharmacological Research, Hanyang University","place":["Ansan, Republic of Korea"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eun Jin","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, College of Pharmacy, Hanyang University","place":["Ansan, Republic of Korea"]},{"name":"Institute of Pharmacological Research, Hanyang University","place":["Ansan, Republic of Korea"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,2,19]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"1640","DOI":"10.1111\/j.1365-2958.2011.07798.x","article-title":"Termination of Vibrio cholerae virulence gene expression is mediated by proteolysis of the major virulence activator, ToxT","volume":"81","author":"Abuaita","year":"2011","journal-title":"Mol. 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