Electronic control of gene expression and cell behaviour in Escherichia coli through redox signalling

Abstract

The ability to interconvert information between electronic and ionic modalities has transformed our ability to record and actuate biological function. Synthetic biology offers the potential to expand communication ‘bandwidth' by using biomolecules and providing electrochemical access to redox-based cell signals and behaviours. While engineered cells have transmitted molecular information to electronic devices, the potential for bidirectional communication stands largely untapped. Here we present a simple electrogenetic device that uses redox biomolecules to carry electronic information to engineered bacterial cells in order to control transcription from a simple synthetic gene circuit. Electronic actuation of the native transcriptional regulator SoxR and transcription from the PsoxS promoter allows cell response that is quick, reversible and dependent on the amplitude and frequency of the imposed electronic signals. Further, induction of bacterial motility and population based cell-to-cell communication demonstrates the versatility of our approach and potential to drive intricate biological behaviours.

Controlling localization of Escherichia coli populations using a two‐part synthetic motility circuit: An accelerator and brake

“…The resulting product was inserted into the pFZY1 vector via BamHI and HindIII restriction enzyme cloning (Koop, Hartley, & Bourgeois, 1987). pT5G construction was described in Tschirhart et al (2017). pHM1 construction: NheI and SacI sites were cloned onto the N-terminus and C-terminus, respectively, of cheZ.…”

“…By placing cheZ under control of SoxR, our goal was to achieve pseudotaxis toward pyocyanin. Our design concept included active degradation of CheZ by the addition of the C‐terminal ClpXP‐targeting domain of YbaQ (Baker & Sauer, ; Flynn, Neher, Kim, Sauer, & Baker, ; Tschirhart et al, ) for enabling rapid turnover and better coordination of the transient CheZ level presumably relative to the CheY level, the result being streamlined regulation of the length and duration of the bacterial “runs.“ Programmed or tailored protein level‐degradation (McGinness, Baker, & Sauer, ) has worked in many systems of metabolic engineering and synthetic biology (Brockman & Prather, ; Copeland, Politz, Johnson, Markley, & Pfleger, ; Sekar, Gentile, Bostick, & Tyo, ), however, to our knowledge few have utilized this concept to help guide pseudotaxis (Hwang et al, ). If engineered pseudotactic cells migrate toward and into a gradient of the pseudoattractant, CheZ proteins will be produced to confer motility.…”

Formate and Nitrate Utilization in Enterobacter aerogenes for Semi‐Anaerobic Production of Isobutanol

“…Recently, several research groups described an electrode‐assisted fermentation method. For example, some of these studies improved n‐butanol production by modulating gene expression and restoring cellular fitness under in anaerobic conditions . Continuous reduction and oxidation reactions occur in the cathode and anode, respectively, which can recycle the redox state of electron mediators without the addition of an external electron donor and acceptor.…”

Precise electronic control of redox reactions inside Escherichia coli using a genetic module

“…Bioelectrochemical devices can then be used to drive biosynthetic reactions 1,4,5 , perform bioelectronic sensing 9 , actuate gene expression 3 , and modulate cellular growth 10,11 within the microorganism of interest. Despite these accomplishments, these strategies couple the redox state of the electrode to multiple intracellular redox biomolecules, resulting in off-target effects, cellular toxicity, and poor control of biosynthesis 1,3,4 . To achieve precise electrochemical control of a biological process, a strategy that couples an electrode to a specific intracellular redox pool is still needed 12,13 .…”