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Synthesis and Assay of Vibrio Quorum Sensing Inhibitors
Published on: May 31, 2024
Directed evolution of the quorum-sensing regulator EsaR for increased signal sensitivity
Jasmine Shong1, Yao-Ming Huang, Christopher Bystroff
1Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, 110 8th St., Troy, NY 12180, USA.
ACS Chemical Biology
|February 1, 2013
Summary
Synthetic biologists engineered new quorum sensing (QS) tools by modifying the EsaR regulator. These enhanced regulators show increased sensitivity to signal molecules, enabling finer control over gene expression in microbial consortia.
Area of Science:
- Synthetic Biology
- Microbiology
- Molecular Biology
Background:
- Cell-cell communication, or quorum sensing (QS), is crucial for engineering microbial consortia.
- Existing QS tools require further development for complex synthetic microbial systems.
- EsaR from Pantoea stewartii is a QS regulator with DNA-binding activity in its unbound state.
Purpose of the Study:
- To engineer EsaR variants with enhanced sensitivity to its cognate signal molecule, 3-oxohexanoyl-homoserine lactone (3OC6HSL).
- To develop novel QS tools for precise control of gene expression in synthetic microbial consortia.
- To expand the toolkit for engineering cell-cell communication-dependent gene expression.
Main Methods:
- Directed evolution was employed to identify EsaR variants with increased signal molecule sensitivity.
- A dual ON/OFF screening strategy was utilized to select for improved EsaR variants.
- The functionality of engineered EsaR variants was assessed at both P(esaR) and P(esaS) promoters.
Main Results:
- Engineered EsaR variants demonstrated over 70-fold increased sensitivity to 3OC6HSL.
- Variants exhibited sensitivity across a 4-log range of signal concentrations.
- Enhanced sensitivity was observed for both repression (at P(esaR)) and activation (at P(esaS)) contexts.
- Gene expression was effectively turned off at lower 3OC6HSL concentrations due to increased sensitivity at P(esaS).
Conclusions:
- Novel EsaR variants provide a new set of tools for engineering cell-cell communication-dependent gene expression.
- These variants offer enhanced signal sensitivity, enabling more dynamic and precise control in synthetic microbial systems.
- The development advances the engineering of synthetic microbial consortia with complex behaviors.
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