<aside> <img src="/icons/light-bulb_gray.svg" alt="/icons/light-bulb_gray.svg" width="40px" /> Overview
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The Emitter Cell produces and releases a chemical signal molecule into the environment. This capacity provides an example of enzymatic small-molecule production, molecule release as a reporter output, inter-cell communication, and co-culture of synthetic cells with living bacteria. The Emitter Cell is largely based on a paper by Jefferson M Smith, Denis Hartmann, and Michael J. Booth: Engineering cellular communication between light-activated synthetic cells and bacteria.
In this first Emitter, the cell produces and releases N-isovaleryl-L-homoserine lactone (IV-HSL). IV-HSL is a branched acyl-homoserine lactone with several advantages for use in the Emitter Cell: it is able to cross the synthetic cell membrane; its uncommon branched-chain structure makes it orthogonal from many other HSLs [Lindemann, 2011]; and it is able to activate expression in signal receiver cells (in this case, E. coli) at very low (picomolar) concentrations [Lindemann, 2011]. The IV-HSL signal is received by a population of E. coli cells, which respond by producing a fluorescent output.
The Detector Cells and Emitter together form the basis for an upcoming Responder Cell; a synthetic cell which can detect a molecular input (such as aTc or IV-HSL itself), and produce a molecular output (IV-HSL) in response. Coupling Detector and Emitter modules will enable signal amplification, where a low amount of a molecule of interest can activate a large population of Responder cells and generate an output that is easy to detect. IV-HSL-detecting Responder Cells could also detect the production of IV-HSL from living cells, providing a means to report on their state in co-culture.
<aside> <img src="/icons/subtask_gray.svg" alt="/icons/subtask_gray.svg" width="40px" /> Design
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The Emitter Cell implements the IV-HSL Emitter Module within a synthetic cell. The Emitter Module produces the BjaI enzyme under the control of a constitutive T7 promoter. BjaI produces IV-HSL from two substrate molecules, S-adenosylmethionine (SAM) and isovaleryl coenzyme A (IV-CoA). IV-HSL diffuses out of the cell, through the lipid bilayer.
<aside> <img src="/icons/wrench_gray.svg" alt="/icons/wrench_gray.svg" width="40px" /> Usage
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Protocol
Modules
DNA Components
pT7-bjaI — Nucleus v0.3.0 Distribution Plate upcoming. Expresses the BjaI enzyme to produce IV-HSL.bjaR-GFP-native —Nucleus v0.3.0 Distribution Plate upcoming. E. coli native receiver module; responds to IV-HSL by producing GFP.Key Materials