Team:ETH Zurich


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Who’s your PABA: intelligent sun protection

E.colipse is an intelligent and adaptive sun radiation protection system which responds to UV exposure with the production of a protective agent. We implemented two different approaches to detect hazardous levels of sun radiation.

The first approach focuses on sensing UV-radiation directly. This system is based on UVR8, a UV sensing protein from plants. In its dark state, this protein forms a homodimer that dissociates upon UV radiation. We fused UVR8 with the DNA binding domain from TetR, which is unable to dimerize and to bind DNA in monomeric form. UV-exposure forces the UVR8-TetR fusion dimer to split, release the DNA and enable transcription. Thus, UVR8-TetR acts as a light-activated on-switch in bacteria.

In the second approach we sense sunlight, and thus indirectly the dangerous UV-radiation, via characteristic wavelengths in the suns emission spectrum. The system then computes its transcriptional output using a hybrid-promoter based biological 2-to-4 decoder.

Finally both approaches trigger the production of para-aminobenzoic acid (PABA), a common ingredient of sunscreen, and various colored pigments as visible warning signals.

Our lab efforts were supported by models in both the direct and the indirect sun light detection strategy as well as in the PABA production.

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