A combination of luxR1 and luxR2 genes activates Pr-promoters of psychrophilic Aliivibrio logei lux-operon independently of chaperonin GroEL/ES and protease Lon at high concentrations of autoinducer

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• 作者：Maria N. Konopleva^b ; Svetlana A. Khrulnova^a ; Ancha Baranova^b ; ^c ; ^d ; Leonid V. Ekimov^b ; Sergey V. Bazhenov^a ; ^b ; Ignatiy I. Goryanin^a ; ^b ; Ilya V. Manukhov^a ; ^b ; ^{manukhov@genetika.ru" class="auth_mail" title="E-mail the corresponding author} ; ^{manukhovi@mail.ru" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Lux-operon ; Aliivibrio ; LuxR ; GroEL/GroES chaperonins ; Protease Lon
• 刊名：Biochemical and Biophysical Research Communications
• 出版年：2016
• 出版时间：13 May 2016
• 年：2016
• 卷：473
• 期：4
• 页码：1158-1162
• 全文大小：645 K

文摘

Lux-operon of psychrophilic bacteria Aliivibrio logei contains two copies of luxR and is regulated by Type I quorum sensing (QS). Activation of lux-operon of psychrophilic bacteria A. logei by LuxR1 requires about 100 times higher concentrations of autoinducer (AI) than the activation by LuxR2. On the other hand, LuxR1 does not require GroEL/ES chaperonin for its folding and cannot be degraded by protease Lon, while LuxR2 sensitive to Lon and requires GroEL/ES. Here we show that at 10⁻⁵ – 10⁻⁴М concentrations of AI a combination of luxR1 and luxR2 products is capable of activating the Pr-promoters of A. logei lux-operon in Escherichia coli independently of GroEL/ES and protease Lon. The presence of LuxR1 assists LuxR2 in gro⁻ cells when AI was added at high concentration, while at low concentration of AI in a cell LuxR1 decreases the LuxR2 activity. These observations may be explained by the formation of LuxR1/LuxR2 heterodimers that act in complex with AI independently from GroEL/ES and protease Lon.

Importance

This study expands current understanding of QS regulation in A. logei as it implies cooperative regulation of lux-operon by LuxR1 and LuxR2 proteins.