28. 11. 2025
Researchers from the Institute of Microbiology of the CAS (IMIC CAS) have authored a review article for a special issue of Current Opinion in Microbiology. The publication highlights an important yet often overlooked mechanism of bacterial gene regulation: dual-promoter systems. These promoter arrangements enable microorganisms to fine-tune gene expression and, in some cases, detect low concentrations of antibiotics and activate protective cellular responses.
Gene expression begins with the transcription of genetic information from DNA into RNA. Central to this process are promoters, short DNA sequences that determine when and to what extent a particular gene is activated. While many genes are controlled by a single promoter, others are regulated by pairs of promoters whose coordinated activity enables precise and dynamic control of gene expression.
In the review, researchers summarize current knowledge of different types of dual-promoter arrangements and their biological significance. These regulatory systems influence a wide range of cellular processes, from stress adaptation and environmental responses to the control of genes associated with antibiotic resistance. The authors also highlight the potential of dual-promoter architectures as tools in synthetic biology, where they could be used for precise control of protein production and coordination of complex metabolic pathways.
Particular attention is given to rifampicin, an antibiotic that inhibits bacterial RNA polymerase. In some bacteria, dual-promoter systems can function as sophisticated sensors of low antibiotic concentrations. When rifampicin is present at sub-inhibitory levels, promoter activity changes in a way that leads to a substantial increase in the expression of protective genes, such as helD and pps.
IMIC researchers from the Laboratory of Microbial Genetics and Gene Expression, together with the Laboratory of Bioinformatics, also combined bioinformatic analyses of dual-promoter systems with searches for a regulatory motif associated with rifampicin resistance. This approach revealed 113 candidate regulatory arrangements, suggesting the existence of previously unexplored mechanisms by which bacteria may defend themselves against antibiotics.
Understanding promoter architecture is essential for both fundamental microbiology and translational research. As antibiotic resistance continues to pose a major global health challenge, deciphering how bacteria sense and respond to antimicrobial compounds may provide valuable clues for future interventions.
PUBLICATION:
P. Sudzinová, T. Knežová Balgová, Š. Bobková, M. Schwarz, L. Krásný. Dual-promoter control of gene expression: from transcriptional fine-tuning to antibiotic resistence. Current Opinion in Microbiology, Volume 91, 2026. doi.org/10.1016/j.mib.2026.102747
Do you want to learn more on dueal-promotors? Read our news on the publication “Bacteria sense the antibiotic rifampicin through a widespread dual-promoter based alarm system,” which was published in the journal Nucleic Acids Research.
