Identification of Inhibitors of the Sigma E/Hfq Pathway in E. coli
Open Access
- Author:
- Reyer, Jessica
- Area of Honors:
- Microbiology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Dr. Sarah Ellen Ades, Thesis Supervisor
Craig Eugene Cameron, Thesis Honors Advisor - Keywords:
- Sigma E
Escherichia coli
antibiotic resistance
Stress response - Abstract:
- Antibiotic resistance has rapidly emerged and spread, which has rendered many common antibiotics ineffective against several diseases. New antibiotics and combination therapies are necessary to combat this ever-growing problem. One potential novel target for new drugs is the Sigma E factor in E. coli. Sigma E is involved in a stress response pathway important for the viability of E. coli and the pathogenicity of other species of bacteria. Inhibiting Sigma E prevents cells from properly repairing the outer membrane proteins, causing cells to lyse. In order to discover new compounds to inhibit this factor, a high-throughput screening of chemical libraries was completed. The screening uses a luciferase-based assay, which allowed for inhibitors of the Sigma E/Hfq pathway to cause bacterial cells to luminesce. In order to find Sigma E-specific inhibitors, secondary assays were performed to characterize inhibitors as inhibiting Sigma E or Hfq, an RNA chaperone that can pair sRNAs transcribed by Sigma E to their mRNA target. The Sigma E-specific assay uses the fluorescence produced by transcription of a fluorescent protein under the control of a Sigma E-dependent reporter. KKL-17131 is a promising inhibitor of Sigma E identified through the initial high-throughput screening. It was further specified as a Sigma E-specific inhibitor through the results obtained with the Sigma E-specific screen and through the presence of an MIC.