iGEM 2012


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miRNA Signal

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  • siRNA Characterization
  • Exosome Isolation and Co-Culturing
  • Cell-Cell Co-Culturing

Protein Signals

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  • GFP
  • rtTA3
  • Cre
  • L7Ae
  • Cas9-VP16

Novel DNA Sensor: Cas9 Split Venus Fusion

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  • Leucine Zipper Fusion
  • DNA Sensing

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L7Ae is an RNA binding protein that represses translation of the targeted transcript. Regulating gene expression on the translational level allows for faster repression of the desired construct than transcriptional repressors. L7Ae targets a specific sequence, called the 2x-kturn, on the 5’ end of the RNA (Saito, 2010). We use L7Ae to repress constitutive 2x-kturn_eGFP. L7Ae can be used to create more complex genetic circuits that are regulated on both the translational and transcriptional level. By targeting L7Ae to exosomes we create the opportunity for the creation of more intricate feedback looks in receiver cells.

Saito, Hirohide. Synthetic translational regulation by an L7Ae–kink-turn RNP switch. Nat Chem Bio. (2010)



To demonstrate L7Ae mediated repression, we transfected constitutively L7Ae and constitutive 2x-kturn_eGFP. As we increased the amount of transfected L7Ae, we saw increased repression of GFP expression.*Note that there was a mistake made in this transfection. 5x the amount of GFP was transfected in the control well; however, L7Ae clearly represses eGFP expression