Project Summary

Our idea

The aim of our project is the design of a standard device to control the synthesis of any protein of interest. This "general-purpose" device, implemented in E. coli, acts at the translational level to allow silencing of protein expression faster than using regulated promoters. We named this device T-REX (Trans Repressor of Expression).

How T-REX works

The device consists of two new BioBricks:

• CIS-repressing, to be assembled upstream of the target coding sequence.

• TRANS-repressor, complementary to the CIS-repressing and placed under the control of a different promoter.

CIS-repressing and TRANS-repressor sequences were designed by BASER software.

Transcription of the target gene yields a mRNA strand - containing the CIS-repressing sequence at its 5' end - available for translation into protein by ribosomes (see Fig. 1, left panel). When the promoter controlling the TRANS coding sequence is active, it drives the transcription of an oligoribonucleotide complementary to the CIS mRNA sequence. The TRANS/CIS RNA duplex prevents ribosomes from binding to RBS on target mRNA, thus silencing protein synthesis. The amount of the TRANS-repressor regulates the rate of translation of the target mRNA (see Fig. 1, right panel)

Figure 1 - T-REX device

How we can test the device


In order to test and characterize our T-REX device, we developed the following genetic circuit (Fig 2):

Figure 2 - Genetic Circuit to test CIS and TRANS' mRNA affinity

More details about our work are reported in the Project section.

Acknowledgements

• University of Bologna

• Ser.In.Ar. Cesena

• Cultural Association San Sebastiano

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