Team:Chiba/Project/Signaling-system

From 2009.igem.org

E.coli Time Manager


The Project

1, Introduction

2, Project Design

3, Experiments, Results & Discussion

3-1, Making LuxR Mutants

3-2, Characterization of LuxR Mutants

3-3, Demonstration

5, Conclusions

Signaling System

Chiba quorumsensing.gif


In this project, we use acylated homoserine lactones (AHLs), signaling molecules used for [http://en.wikipedia.org/wiki/Quorum_sensing quorum sensing] in gram negative bacteria. Senders express LuxI or similar enzymes, which catalyze the production of AHLs, under the control of a constitutive (Tet) promoter. Each cell thus generates AHL more or less at a constant rate. AHL can freely permeate cell membranes and are detected by neighboring cells. Receivers constitutively express LuxR proteins (or a similar ortholog), the protein that detects AHL concentrations. When AHLs bind LuxR proteins, the AHL-LuxR complex activates the Lux promoter. The threshold [AHL] at which switching occurs is determined by the affinity of AHL for the particulr LuxR ortholog. about quorum sensing)