Proteolysis of ToxR is controlled by cysteine-thiol redox state and bile salts in Vibrio cholerae.

ABSTRACT: In Vibrio cholerae, virulence gene expression is regulated by a transmembrane-localized transcription factor complex designated as ToxRS. ToxR harbours two cysteines in the periplasmic domain that can form inter- and intramolecular disulfide bonds. In this study, we investigated the σ^E -dependent inner membrane proteolysis of ToxR, which occurs via the periplasmic-localized proteases DegS and DegP. Both proteases respond to the redox state of the two cysteine thiol groups of ToxR. Interestingly, in the presence of sodium deoxycholate, ToxR proteolysis is blocked independently of ToxS, whereas ToxR activation by bile salts requires ToxS function. From these data, we identified at least two levels of control for ToxR activation by sodiumdeoxycholate. First, bile inhibits ToxR degr

SUBMITTER: Lembke M 

PROVIDER: S-EPMC6242745 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature