Investigating the co-regulation of gene expression by CsrA and Hfq in Escherichia coli
Research Poster Health & Life Sciences 2025 Graduate ExhibitionPresentation by Rohan Deshmukh
Exhibition Number 216
Abstract
Global post-transcriptional regulation in E. coli is mediated by CsrA and Hfq, two important RNA binding proteins. CsrA regulates translation initiation of several hundred genes, while its activity is controlled by two sRNA antagonists (CsrB and CsrC). Hfq also regulates the expression of hundreds of genes by mediating sRNA-mRNA base-pairing. Much is known about the workings of the Csr and Hfq system independently, however recent research indicates that Hfq and CsrA bind many of the of the same sRNAs, suggesting a possible interplay between the two systems that could impact expression of several mRNAs that base pair with these sRNAs. This study aims to identify potential co-regulation by CsrA and Hfq on the expression of select genes and to characterize potential mechanisms responsible for the observed regulation. The regulatory impact of Hfq and CsrA on target mRNAs will be determined by measuring the expression of reporter fusions in strains carrying mutations in csrA, hfq, or both. Additionally, gel shift assays will be used to measure the affinity of CsrA and Hfq for the sRNA targets, both together and separately. Combined, these assays should provide us a better understanding of whether CsrA and Hfq regulate target gene expression in a cooperative or in an antagonistic manner, thereby providing important mechanistic information that controls global bacterial physiology.
Importance
CsrA, Hfq, and sRNAs play crucial roles in bacterial metabolism, virulence and stress responses. Understanding these regulatory processes can help us to create novel strategies in controlling bacterial infections by finding new targets for antimicrobials as targeting these regulatory systems can affect important bacterial functions. Studying these regulatory systems can also help us construct new metabolic circuits that might have applications in the biotechnology industry.