Sponge RNA controlled quorum sensing transition in Vibrio cholerae

• Applicant: Professor Dr. Kai Papenfort
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms ; Medical Microbiology and Mycology, Hygiene, Molecular Infection Biology ; Parasitology and Biology of Tropical Infectious Disease Pathogens
• Term: from 2015 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 285804960

Quorum sensing (QS) is a central behavior-coordination mechanism in many microorganisms. In Vibrio cholerae, a major human pathogen and model organism for studying microbial communication, QS is key for various collective functions including biofilm formation and virulence. To accurately execute QS behaviors, V. cholerae must detect, interpret, and integrate extracellular chemical signaling molecules (called autoinducers) and convert that information into changes in gene expression. To this end, V. cholerae employs an array of transcriptional regulators and small regulatory RNAs (sRNAs) building an interconnected network guaranteeing optimal QS performance. In this project, we aim to study a previously unknown component of the network, called QrrS. QrrS belongs to the yet poorly studied group of sponge RNAs, i.e. non-coding regulators that act specifically to counteract the action of another non-coding regulator. The preliminary data presented in this proposal show that QrrS base-pairs with and inhibits the function of the Qrr1-4 sRNAs, which are the principal regulatory components of the QS pathway in V. cholerae. Indeed, we discovered that V. cholerae cells lacking qrrS fail to shift accurately from low- to high-cell densities and consequently we predict that QrrS affects gene expression at a global scale. We also identified a new transcriptional regulator (QrrT) driving qrrS expression, which we also aim to study in this project. Together, we believe that the proposed research will make an important contribution to the QS pathway in V. cholerae, but will also add to a more general understanding of QS network architectures and how sponge RNAs are integrated into these systems.

• DFG Programme: Research Grants