Stationary‐phase induction of vvpS expression by three transcription factors: repression by LeuO and activation by SmcR and CRP. Issue 2 (9th May 2015)

• Record Type: Journal Article
• Authors: Kim, Jeong‐A.; Park, Jin Hwan; Lee, Mi‐Ae; Lee, Hyun‐Jung; Park, Soon‐Jung; Kim, Kun‐Soo; Choi, Sang‐Ho; Lee, Kyu‐Ho
• Is Part Of: Molecular microbiology. Volume 97:Issue 2(2015)
• Page Start: 330
• Page End: 346
• Publication Date: 2015-05-09
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.13028
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>An exoprotease of <italic>V</italic><italic>ibrio vulnificus</italic>, VvpS, exhibits an autolytic function during the stationary phase. To understand how <italic>vvpS</italic> expression is controlled, the regulators involved in <italic>vvpS</italic> transcription and their regulatory mechanisms were investigated. LeuO was isolated in a ligand‐fishing experiment, and experiments using a <italic>leuO</italic>‐deletion mutant revealed that LeuO represses <italic>vvpS</italic> transcription. LeuO bound the extended region including LeuO‐binding site (LBS)‐I and LBS‐II. Further screening of additional regulators revealed that SmcR and cyclic adenosine monophosphate‐receptor protein (CRP) play activating roles in <italic>vvpS</italic> transcription. SmcR and CRP bound the regions overlapping LBS‐I and ‐II, respectively. In addition, the LeuO occupancy of LBS‐I and LBS‐II was competitively exchanged by SmcR and CRP, respectively. To examine the mechanism of stationary‐phase induction of <italic>vvpS</italic> expression, <italic>in vivo</italic> levels of three transcription factors were monitored. Cellular level of LeuO was maximal at exponential phase, while those of SmcR and CRP were maximal at stationary phase and relatively constant after the early‐exponential phase, respectively. Thus, <italic>vvpS</italic> transcription was not induced during the exponential phase by high cellular content of LeuO. When entering the stationary phase, however, LeuO content was significantly reduced and repression by LeuO was relieved through simultaneous binding of SmcR and CRP to LBS‐I and ‐II, respectively.</p> </abstract>