Difference between revisions of "Part:BBa K2610034"

Revision as of 00:48, 18 October 2018

pSoxS-GFP-pSoxS-GFP

This composite part features twice the regulatory part promoter SoxS (BBa_K2610030) and the fluorescent protein GFP (BBa_E0040). It can be used to visualize upregulation of SoxS as a result of superoxide stress.

Regulatory protein SoxS is involved in the superoxide pathway in Escherichia coli. It acts as a superactivator of downstream stress genes.

Usage and Biology

We, iGEM Leiden 2018, have designed this composite part as part of our project Fifty Shades of Stress. This reporter part allowed us to detect stress-induced changes in SoxS transcription. We have created this part in order to amplify the fluorescent signal measured after pSoxS-GFP activation.

As can be observed in Figure 1 the double promoter and GFP construct leads to an increased median fluorescence intensity compared to pSoxS-GFP. This activation was demonstrated through treatment of the transformed E.coli cells with nalidixic acid.

Figure 1. Median fluorescence intensity (MFI) as a result of treatment with nalidixic acid for three promoter-GFP constructs.

Dose-dependency studies

After determination of the specific response to nalidixic acid, we assessed the dose-dependency of this reporter. We found that an increase in nalidixic acid concentration of nalidixic acid leads to an increasing mean fluorescence intensity (MFI). A decrease in detected GFP expression at higher concentrations can be attributed to the lethality of the stressor.

Figure 2. Dose-response curve as a result of treatment with nalidixic acid.

Sequence and Features