Activity of the Bacillus thuringiensis NprR–NprX cell–cell communication system is co‐ordinated to the physiological stage through a complex transcriptional regulation. Issue 1 (6th March 2013)

• Record Type: Journal Article
• Authors: Dubois, Thomas; Perchat, Stéphane; Verplaetse, Emilie; Gominet, Myriam; Lemy, Christelle; Aumont‐Nicaise, Magali; Grenha, Rosa; Nessler, Sylvie; Lereclus, Didier
• Is Part Of: Molecular microbiology. Volume 88:Issue 1(2013)
• Page Start: 48
• Page End: 63
• Publication Date: 2013-03-06
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.12168
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>NprR is a quorum sensor of the RNPP family found in bacteria of the <italic>Bacillus cereus</italic> group. In association with its cognate peptide NprX, NprR controls the expression of genes essential for survival and sporulation of <italic>Bacillus thuringiensis</italic> during its necrotrophic development in insects. Here, we report that the <italic>nprR</italic><italic>–</italic><italic>nprX</italic> genes are not autoregulated and are co‐transcribed from a σ<sup>A</sup>‐dependent promoter (P<sub>A</sub>) located upstream from <italic>nprR</italic>. The transcription from P<sub>A</sub> starts at the onset of the stationary phase and is controlled by two transcriptional regulators: CodY and PlcR. The nutritional repressor CodY represses <italic>nprR</italic><italic>–</italic><italic>nprX</italic> transcription during the exponential growth phase and the quorum sensor PlcR activates <italic>nprR</italic><italic>–</italic><italic>nprX</italic> transcription at the onset of stationary phase. We show that <italic>nprX</italic> is also transcribed independently of <italic>nprR</italic> from two promoters, P<sub>H</sub> and P<sub>E</sub>, dependent on the sporulation‐specific sigma factors, σ<sup>H</sup> and σ<sup>E</sup> respectively. Both promoters ensure <italic>nprX</italic> transcription during late stationary phase while transcription from P<sub>A</sub> has decreased. These results show that the activity of the NprR–NprX quorum sensing system is tightly co‐ordinated to the physiological stage throughout the developmental process of the <italic>Bacillus</italic>.</p> </abstract>