Elucidating the roles of 2′, 3′‐cyclic nucleotide monophosphates in bacterial signaling and stress response

To survive extreme and rapidly changing conditions, bacteria sense environmental changes and then respond with appropriate alterations in gene expression and protein activity. Bacterial adaptation to environmental signals plays important roles in human health, including how bacteria respond to anti‐bacterial treatments and how bacteria switch from free‐living to invading a host. Therefore, an important scientific challenge is to identify mechanisms that allow bacterial to sense external cues and translate those cues into internal signals that maximize survival. Novel intracellular small molecule signals, 2’, 3’‐cyclic nucleotide monophosphates (2’, 3’‐cNMPs), have been recently discovered in eukaryotes and prokaryotes. Within plants and mammals, wounding has been found to cause increased levels of 2’, 3’‐cNMPs, suggesting an intriguing connection between 2’,3’‐cNMPs and cellular stress [1‐3] . However, not much is known about these unusual nucleotides in bacteria, even though 2’,3’‐cNMPs were originally detected in Escherichia coli over five decades ago. My research focus on determining the functions of 2, 3‐cyclic nucleotide monophosphates (2’, 3′‐cNMPs) in bacterial signaling, as well as the enzymes responsible for 2’,3’‐cNMP production and degradation. 2’, 3’‐cNMP levels in E. coli are generated specifically from RNase I‐catalyzed RNA degradation and RNase I and 2’, 3’‐cNMP levels play important roles in controlling biofilm formation [4] . I am investigating the proteins and pathways involved in prokaryotic 2’, 3’‐cNMP production, degradation, and stress response pathways, with the aim to develop a mechanistic understanding of 2’,3’‐cNMP signaling. To identify 2’,3’‐cNMP‐sensing proteins, I synthesize 2’,3’‐cNMP based molecules and use it as a bait in affinity‐based chromatography to capture the proteins and validate their role in signal transduction. My recent experiments have revealed multiple protein hits, that are involved in RNA salvage, among them ribosomal proteins are most abundant. Therefore, I am currently investigating the role of 2’,3’‐cNMP in the “central dogma” of bacterial cells. By elucidating the role(s) of 2’,3’‐cNMPs in bacterial signaling pathways and stress responses, this research has the potential to methods to control bacterial phenotypes and potentially discover new targets for antibacterial therapies. A successful completion of this goal has the potential to provide new treatments for antibiotic resistant bacteria, decreasing the mortality and cost associated with infections. References: [1] Azarashvili, T., Krestinina, O., Galvita, A., Grachev, D., Baburina, Y., Stricker, R., Evtodienko, Y., and Reiser, G. (2009). Am. J. Physiol. Cell Physiol. 296 , C1428‐1439. [2] Jackson, E. K. (2011) The 2′,3′‐cAMP‐adenosine pathway, Am. J. Physiol. Renal. Physiol. 301 , F1160‐1167. [3] Van Damme, T., Blancquaert, D., Couturon, P., Van Der Straeten, D., Sandra, P., and Lynen, F. (2014). Phytochemistry , 103 , 59‐66. [4] Fontaine, B. M., Martin, K. S., Garcia‐Rodriguez, J. M., Jung, C., Briggs, L., Southwell, J. E., Jia, X., and Weinert, E.E. (2018). Biochemical Journal. 475, 1491–1506