Team:Grenoble/Biology/Network

From 2012.igem.org

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<h2 id="10">The signaling module</h2>
<h2 id="10">The signaling module</h2>
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The signaling module allows our bacteria strain to integrate the input signal = the pathogene presence.<br/>
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The signaling module allows our bacteria strain to integrate the input signal = the presence of a pathogene.<br/>
<br/>
<br/>
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You can find here the <a href="http://2012.igem.org/Team:Grenoble/Modeling/Signaling">modelization</a> of this module.<br/>
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You can find <a href="http://2012.igem.org/Team:Grenoble/Modeling/Signaling">here</a> the mathematical model and numerical simulation this module.<br/>
<br/>
<br/>
<center><img src="http://2012.igem.org/wiki/images/e/e1/Signaling_gre.png"/></center>
<center><img src="http://2012.igem.org/wiki/images/e/e1/Signaling_gre.png"/></center>
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Once <i>S. aureus</i> is present, the linker is cut by the toxin and the dipeptide is released.<br/>
Once <i>S. aureus</i> is present, the linker is cut by the toxin and the dipeptide is released.<br/>
<br/>
<br/>
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The dipeptide binds its receptor which was engineered <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[3]</a> <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[4]</a> by the team:  
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The dipeptide binds an engineered receptor <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[3]</a> <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[4]</a> that consists of:  
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<ul><li>the extracellular part of Tap <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[5]</a> is a dipeptide receptor involved in the chemotaxism</li>
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<ul><li>the extracellular part of Tap <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[5]</a>, a dipeptide receptor involved in the chemotaxism</li>
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<li>the intracellular part of EnvZ <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[6]</a> is a histidine kinase involved in the osmoregulation</li>
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<li>the intracellular part of EnvZ <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[6]</a>, a histidine kinase involved in the osmoregulation</li>
</ul>
</ul>
<br/>
<br/>
Once the dipeptide binds the Tap part <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[7]</a>, the intracellular EnvZ part allows the phosphorylation of OmpR <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[8]</a> <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[9]</a>, which is a constitutively produced transcriptional activator.<br/>
Once the dipeptide binds the Tap part <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[7]</a>, the intracellular EnvZ part allows the phosphorylation of OmpR <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[8]</a> <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[9]</a>, which is a constitutively produced transcriptional activator.<br/>
<br/>
<br/>
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OmpR phosphorylation's allows the activation of the ompC promoter <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[10]</a>.
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OmpR phosphorylation allows the activation of the ompC promoter <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[10]</a>. We introduced <i>cyaA</i> (that code for adenyl cyclase) downstream of this promoter.
</section>
</section>
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The amplification module allows our bacteria to amplify the input signal and to produce an output signal = fluorescence.<br/>
The amplification module allows our bacteria to amplify the input signal and to produce an output signal = fluorescence.<br/>
<br/>
<br/>
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As for the previous module you can read our <a href="http://2012.igem.org/Team:Grenoble/Modeling/Amplification">modelization</a>.<br/>
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As for the previous module you can read <a href="http://2012.igem.org/Team:Grenoble/Modeling/Amplification">here</a> our mathematical model and numerical simulation.<br/>
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<br/>
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<center><img src="http://2012.igem.org/wiki/images/f/fc/Amplifcation1.png"/></center>
<center><img src="http://2012.igem.org/wiki/images/f/fc/Amplifcation1.png"/></center>
<br/>
<br/>
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<center><img src="http://2012.igem.org/wiki/images/c/c7/AND.png"/></center>
<center><img src="http://2012.igem.org/wiki/images/c/c7/AND.png"/></center>
<br/>
<br/>
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The binding of cAMP to CRP (C-reactive protein) leads to the production of AraC by activating the pmalT promoter <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[12]</a>.<br/>
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The binding of cAMP to CRP (cAMP Receptor Protein) leads to the production of AraC by activating the pmalT promoter <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[12]</a>.<br/>
In the presence of arabinose, AraC and cAMP-CRP, cooperatively activate the paraBAD promoter <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[13]</a>, thus forming an "AND" gate. This allows the production of:
In the presence of arabinose, AraC and cAMP-CRP, cooperatively activate the paraBAD promoter <a href="http://2012.igem.org/Team:Grenoble/Biology/Network#30">[13]</a>, thus forming an "AND" gate. This allows the production of:
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<ul><li>Adenyl cyclase which reproduces cAMP, forming thus an amplification loop
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<ul><li>Adenyl cyclase which reproduces cAMP, forming thus a positive amplification loop
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<li>GFP (Green Fluorescent Protein) = our output signal
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<li>GFP (Green Fluorescent Protein) = the output signal
</ul>
</ul>
</section>
</section>

Revision as of 15:27, 26 September 2012

iGEM Grenoble 2012

Project

Network details

Our system is divided in two modules:

The signaling module

The signaling module allows our bacteria strain to integrate the input signal = the presence of a pathogene.

You can find here the mathematical model and numerical simulation this module.


The idea behind this module comes from the iGEM London Imperial College 2010 Team's work on Parasight [1].

Staphylococcus aureus secretes the exfoliative toxin B [2] which cleaves a specific amino-acids sequence (Desmoglein 1). This specific sequence can be used as a linker between a membrane protein and a dipeptide.
Once S. aureus is present, the linker is cut by the toxin and the dipeptide is released.

The dipeptide binds an engineered receptor [3] [4] that consists of:
  • the extracellular part of Tap [5], a dipeptide receptor involved in the chemotaxism
  • the intracellular part of EnvZ [6], a histidine kinase involved in the osmoregulation

Once the dipeptide binds the Tap part [7], the intracellular EnvZ part allows the phosphorylation of OmpR [8] [9], which is a constitutively produced transcriptional activator.

OmpR phosphorylation allows the activation of the ompC promoter [10]. We introduced cyaA (that code for adenyl cyclase) downstream of this promoter.

Amplification module

The amplification module allows our bacteria to amplify the input signal and to produce an output signal = fluorescence.

As for the previous module you can read here our mathematical model and numerical simulation.

The activation of the ompC promoter allows the production of Adenyl cyclase [11]. Adenyl cyclase catalyses the conversion of ATP (Adenosine Tri-Phosphate) into cAMP (cyclic Adenosine Mono-Phosphate).


The binding of cAMP to CRP (cAMP Receptor Protein) leads to the production of AraC by activating the pmalT promoter [12].
In the presence of arabinose, AraC and cAMP-CRP, cooperatively activate the paraBAD promoter [13], thus forming an "AND" gate. This allows the production of:
  • Adenyl cyclase which reproduces cAMP, forming thus a positive amplification loop
  • GFP (Green Fluorescent Protein) = the output signal

Cell to cell communication module

When a bacterium detects S. aureus, it produces a several molecules of GFP and evenmore cAMP. cAMP diffuses through the membrane and activates the amplification loop in all the neighbouring bacteria [14], which triggers the production of GFP and cAMP.
This leads to an entire population which produces GFP where only a bacterium detected the pathogen in the first place:


References