{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T23:37:37Z","timestamp":1789688257413,"version":"4.0.1"},"reference-count":35,"publisher":"Springer Science and Business Media LLC","issue":"1","content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["BMC Microbiol"],"published-print":{"date-parts":[[2010,12]]},"abstract":"<jats:title>Abstract<\/jats:title>\n          <jats:sec>\n            <jats:title>Background<\/jats:title>\n            <jats:p>\n              <jats:italic>Vibrio cholerae<\/jats:italic> is the causative agent of cholera. Extensive studies reveal that complicated regulatory cascades regulate expression of virulence genes, the products of which are required for <jats:italic>V. cholerae<\/jats:italic> to colonize and cause disease. In this study, we investigated the expression of the key virulence regulator ToxR under different conditions.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Results<\/jats:title>\n            <jats:p>We found that compared to that of wild type grown to stationary phase, the <jats:italic>toxR<\/jats:italic> expression was lower in an <jats:italic>aphB<\/jats:italic> mutant strain. AphB has been previously shown to be a key virulence regulator that is required to activate the expression of <jats:italic>tcpP<\/jats:italic>. When expressed constitutively, AphB is able to activate the <jats:italic>toxR<\/jats:italic> promoter. Furthermore, gel shift analysis indicates that AphB binds <jats:italic>toxR<\/jats:italic> promoter region directly. We also characterize the effect of AphB on the levels of the outer membrane porins OmpT and OmpU, which are known to be regulated by ToxR.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Conclusions<\/jats:title>\n            <jats:p>Our data indicate that <jats:italic>V. cholerae<\/jats:italic> possesses an additional regulatory loop that use AphB to activate the expression of two virulence regulators, ToxR and TcpP, which together control the expression of the master virulence regulator ToxT.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1186\/1471-2180-10-3","type":"journal-article","created":{"date-parts":[[2010,1,6]],"date-time":"2010-01-06T19:15:17Z","timestamp":1262805317000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":34,"title":["Virulence regulator AphB enhances toxR transcription in Vibrio cholerae"],"prefix":"10.1186","volume":"10","author":[{"given":"Xiao","family":"Xu","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew M","family":"Stern","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhi","family":"Liu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Biao","family":"Kan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jun","family":"Zhu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2010,1,6]]},"reference":[{"issue":"2","key":"959_CR1","doi-asserted-by":"publisher","first-page":"271","DOI":"10.1016\/0092-8674(87)90430-2","volume":"48","author":"VL Miller","year":"1987","unstructured":"Miller VL, Taylor RK, Mekalanos JJ: Cholera toxin transcriptional activator toxR is a transmembrane DNA binding protein. 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