Engineering cellular communication between light-activated synthetic cells and bacteria

Gene-expressing compartments assembled from simple, modular parts, are a versatile platform for creating minimal synthetic cells. In a manner synonymous with natural cells, these life-like assemblies utilise information encoded in DNA within the compartment’s interior to dictate which proteins are expressed and consequently the overall function of the synthetic cell. Hence, by incorporating gene regulatory motifs into the DNA templates, in situ gene expression can be controlled according to specific stimuli. In this work, cell-free protein synthesis within synthetic cells was controlled using light by encoding genes of interest on light-activated DNA templates. Light-activated DNA contained a photocleavable blockade within the T7 promoter region that tightly repressed transcription until the blocking groups were removed with UV light. In this way, synthetic cells were activated remotely, in a spatiotemporally controlled manner. By applying this strategy to the expression of an acyl homo-serine lactone synthetase, BjaI, quorum-sensing based communication between synthetic cells and bacteria was controlled with light. This work provides a framework for the remote-controlled production and delivery of small molecules from non-living matter to living matter, with applications in biology and medicine.