2019/12/03 by Ruibin Zhang, Leyla Slamti, Lei Tong +9 · 1 citation
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Bacillus and Francisella bacterial research #Insect Resistance and Genetics #Insect and Pesticide Research
paper · pdf · doi:10.1111/mmi.14439
openalex publication_date 2019/12/03 · openalex created_date 2019/12/13 · openalex updated_date 2026/07/30
Cell differentiation within an isogenic population allows the specialisation of subpopulations and a division of labour. Bacillus thuringiensis is a spore-forming bacterium that produces insecticidal crystal proteins (Cry proteins) in sporulating cells. We recently reported that strain B. thuringiensis LM1212 presents the unique ability to differentiate into two subpopulations during the stationary phase: spore-formers and crystal-producers. Here, we characterised the transcriptional regulator CpcR responsible for this differentiation and the expression of the cry genes. cpcR is located on a plasmid that also harbours cry genes. The alignment of LM1212 cry gene promoters revealed the presence of a conserved DNA sequence upstream from the -35 region. This presumed CpcR box was also found in the promoter of cpcR and we showed that cpcR transcription is positively autoregulated. Electrophoretic mobility shift assays suggested that CpcR directly controls the transcription of its target genes by binding to the CpcR box. We showed that CpcR was able to direct the production of a crystal consisting of a heterologous insecticidal Cry protein in non-sporulating cells of a typical B. thuringiensis kurstaki strain. Moreover, the expression of cpcR induced a reduction in the sporulation of this B. thuringiensis strain, suggesting an interaction between CpcR and the sporulation regulatory networks.