Project Summary

Our idea

The aim of our project is the design of a new device to control the synthesis of any protein of interest. This "general-purpose" standard device, implemented in E. coli, acts at the translational level to allow a switch in protein expression faster than transcriptional promoter regulation. 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, right panel). Induction of the promoter controlling the TRANS coding sequence, releases a transcript complementary to the CIS mRNA sequence. The TRANS/CIS RNA duplex prevents ribosomes from binding to RBS on target mRNA, thus repressing protein synthesis. The amount of the TRANS-repressor regulates the rate of translation of the target mRNA (see Fig. 1, left 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

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

Acknowledgements

• [http://www.unibo.it/Portale/default.htm University of Bologna]

• [http://serinar.criad.unibo.it Ser.In.Ar. Cesena]

• Cultural Association San Sebastiano

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