Team:Chiba/Project

Introduction

Project Design

Signaling System

In this project, we use acylated homoserine lactones (AHLs), signaling molecules used for 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. (more about quorum sensing)

Constructing A Delay Switch, Multiple Ways

2008のことを述べ、Mutantの実験をやってない（今年はやる）とせつめい。

In principle, there are three ways to delay the activation of chemical communications;

1. Silencing the Speakers: Rate of signal accumulation down-regulated, for instance, by slowing down the signal generators.
2. Desensitize Receivers: Switching threshold elevated, for instance, by using insensitive receiver/ reporter systems.
3. Partial Blocking: Decreasing the by chewing the signal up.

Constructing A Flow of Activation

1, Parallel Activation

2, Series Activation

Conclusions