Difference between revisions of "Part:BBa K2315011"

Latest revision as of 13:54, 1 November 2017

LasR-pLas-GFP
Group: Shanghaitech iGEM 2017

The HSL receiver LasR from Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1) activates expression of GFP protein in response to 3OC12HSL.

This Receiver can be easily replaced by other AHL receivers in our collection. A full collection could be found in: http://2017.igem.org/Team:Shanghaitech/Library

Usage and Biology

Fig. 1 Genetic Circuit Design

When AHL is added with concentration higher than a critical value, the constitutively expressed LasR will bind to the AHL molecule 3OC12HSL, dimerize and bind to the pLas regulatory sequence to activate GFP expression.

Fluorescent Response to cognate 3OC12-HSL

To test this part, we used standard 3OC12HSL (HSL produced by LasI in P.aeruginosa) to determine the response curve.

Fig. 1 LasR-pLas-GFP‘s response to cognate 3OC12HSL

Orthogonality test against non-cognate inducers

We have characterized crosstalk response of LasR to several non-cognate AHLs:

Fig. 2 Orthogonality test of LasR-pLas-GFP (i):Fluorescent response to cognate and non-cognate AHLs (ii)Dose-Response curves for cognate and non-cognate AHLs (iii-vi)Fluorescent response to non-cognate AHLs in compared with 3OC12-HSL

It has shown that LasR is sensitive to it's cognate HSL and has obvious crosstalk with 3OC8-HSL in Tra System in relatively high concentration.

Usages in our Project

We developed a measurement protocol using the fluorescent protein coupled AHL receiver germs to measure the actual AHLs concentration in high precision and sensitivity in compared with LC-MS.

LasR-pLas-GFP Sequence and Features