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From 2012.igem.org

Synchronized bacterial clock

Human orchestrate their activities in different places because of their synchronizing clocks. Isn't it cool if bacteria can coordinate their molecular timepieces in the same way as we human do?

We found that Hasty and colleagues have constructed a network of genes and proteins in E.coli that acts as a molecular clock and can be synchronized across a population of the bacteria. The mechanism can be described briefly as follows.

A promoter(PluxI)drives the production of LuxI, an enzyme that synthesizes the quorumsensing signal acyl-homoserine lactone (AHL). Another PluxI control ths the production of AiiA, a protein that catalyses the degradation of AHL, and a third PluxI triggers the synthesis of a variant of green fluorescent protein called yemGFP. An AHL receptor, LuxR, is constitutively expressed. The authors combined these components to form an autoinducng circuit (AHL activates LuxR, and the AHL-LuxR complex induces PluxI-driven luxI transcription and yemGFP production) with a time-delayed negative feedback loop (the AHL-LuxR complex induces PluxI-driven production of AiiA, which degrades AHL). The result was a population of bacteria that produce synchronized pulses of fluorescence, coordinated by quorum sensing.

(From "Synthetic biology: synchronized bacterial clock")

We expect to apply the network to medical field. Since the network can make an oscillation, it can be used to release medicine periodically. What is more, we wish to add another sensor in the network. The sensor can sense a signal which is released because of a certain disease, and thus the cells can sense the signal and start the oscillation which releases the medicine periodically. For instance, when a man hasdiabetes, the high density blood sugar will start an insulin-releasing oscillation.

Reference:

1. "Synthetic biology: synchronized bacterial clock"

2. "A synchronized quorum of genetic clock"

3. "bacteria collaborate to sense arsenic"