Part:BBa_R0071:Experience

Fig. 1. Fluorescence intensity detected by flow cytometer

Fig. 2. The fluorescence intensity of the cells with the original Prhl, Prhl(RR), and Prhl(RL)

We, Tokyo Tech 2014, improved Prhl Promoter (BBa_R0071) by changing LuxR binding site of Plux Promoter to RhlR binding site.
We measured the GFP expression with the four different promoters (Prhl, Prhl(RR):BBa_K1529320, Prhl(LR):BBa_K1529310 and Prhl(RL):BBa_K1529300) by flow cytometer. Each promoter was tested in the presence and also in the absence of C4HSL.
Fig. 1 shows the fluorescence intensity detected by flow cytometer.
Fig. 2 is the extracted data which shows the comparison of the promoters: Prhl, Prhl(RR), and Prhl(RL).
As Fig. 2 shows, when induced by C4HSL, Prhl(RR) promoter showed higher maximum expression level and higher leak than the original Prhl promoter.
Although Prhl(RL) promoter had lower maximum expression level compared to Prhl(RR) promoter, it had the highest induced/not-induced ratio.
This means Prhl(RL) promoter has little leak.
Therefore, we can say that Prhl(RL):BBa_K1529300 promoter is the best improved Prhl promoter due to the advantages of less leak and higher expression level.

For more information, see [http://2014.igem.org/Team:Tokyo_Tech/Experiment/Prhl_reporter_assay our work in Tokyo_Tech 2014 wiki].

User Reviews

UNIQc3d3ce2c550e7260-partinfo-00000005-QINU UNIQc3d3ce2c550e7260-partinfo-00000006-QINU

No review score entered. Northwestern 2011

The 2011 Northwestern iGEM team used this promoter as a unit within our Pseudomonas Aeruginosa biosensor. When this RhlR/C4-HSL regulated promoter is induced at varying concentrations of C4-HSL, we observed GFP fluorescence in accordance to the graph below.

;