Novel prokaryotic sensing and regulatory system employing previously unknown nucleic acids-based receptors

The present study describes a previously unknown universal signaling and regulatory system, which we named TRB receptor system. This system is responsible for sensing, remembering, and regulating cell responses to various chemical, physical or biological stimuli. It controls cell survival, variability, reproduction, adaptation, genome changes, and gene transfer. Importantly, the TRB-receptor system is responsible for the formation and maintenance of cell memory, as well the ability to "forget" preceding events. The system is composed of DNA- and RNA-based receptors located outside the membrane named "TezRs", as well as reverse transcriptases and integrases. The sensory and regulatory functions of TezRs enable the TRB-receptor system to control all major aspects of bacterial behavior, such as growth, biofilm formation and dispersal, utilization of nutrients including xenobiotics, virulence, chemo- and magnetoreception, response to external factors (e.g., temperature, UV, light and gas content), mutation events, phage-host interaction and recombination activity. Additionally, it supervises the function of other receptor-mediated signaling pathways. Transcriptome analysis revealed that the loss of different TezRs instigates significant alterations in gene expression. HIGHLIGHTSThe TRB-receptor system regulates bacterial sensing and response to various stimuli. The TRB-receptor system is responsible for maintenance and loss of cell memory. The TRB-receptor system comprises DNA- and RNA-based "TezRs" receptors. The TRB-receptor system relies on reverse transcriptases and recombinases. The TRB-receptor system oversees other receptor-mediated signaling pathways. TezRs are implicated in cell mutation and recombination events.