Network details

• signaling module
• amplification module
  

  Signaling module

  The signaling module allows our bacterial strain to integrate the input signal = the pathogene presence.
  Stapylococcus aureus secrete a protease nom de la protéase which cut a specific amino-acids sequence. 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 protease and the dipeptide is released.
  
  The dipeptide binds to his receptor which is an engineered receptor:

  • the extracellular part is the extracellular part of Tap, a dipeptide receptor involved in the chemotaxism
  • the intracellular part is the intracellular part of EnvZ, a kinase involved in the osmoregulation

  
  Once the dipeptide is bound, the EnvZ part allows the phosphorylation of OmpR, a transcriptional activator.

  Amplification module

  The amplification module allows our bacterial strain to amplify the input signal and to produce an output signal = fluorescence.
  
  Once OmpR is phosphorylated, it allows the production of adenyl cyclase by activating the OmpC promoter.
  Adenyl cyclase is an enzyme which catalyse the conversion of ATP (Adenosine Tri-Phosphate) to cAMP (cyclic Adenosine Mono-Phosphate).
  
  
  cAMP binds to CRP (C-reactive protein) and then this complex allows the production of AraC by activating pMalT promoter.
  In the presence of arabinose, AraC, with cAMP-CRP, activates the pAraBAD promoter which allow the production of:

  • adenyl cyclase which reproduce cAMP forming an amplification loop
  • GFP (Green Fluorescent Protein) = our output signal