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Discover our dual-key regulatory mechanism
An Interactive Dual-Key Regulatory System
Click on the inhaler to explore the system
Discover our dual-key regulatory mechanism| ID | Part Name | Part type | Short description | Designer |
|---|---|---|---|---|
| BBa_25EPMLGZ | P11 Promoter | Semi-synthetic Promoter | Semi-synthetic promoter providing stable, predictable gene expression. | AFCM-Egypt iGEM team 2025 |
| BBa_K2934002 | KatA promoter | Conditioning promoter | Detects H₂O₂ and activates gene expression under oxidative stress. | Technion-Israel 2019 |
| BBa_K1677301 | P170-CP25 Promoter | conditioning promoter | Activates LacR expression in acidic conditions. | BABS_UNSW_Australia 2015 |
| BBa_K4687048 | J23119 Promoter | Constitutive promoter | Strong, constitutive promoter for continuous gene expression. | Yiming Jiang Group 2023 |
| BBa_K3482000 | heat-inducible RNA-thermosensor 2U | conditioning promoter | This is a heat-inducible RNA-thermosensor 2U used for expressing a toxin-antitoxin system in response to heat. | Thierry Marti 2020 |
| BBa_K3482013 | pPhoB promoter | conditioning promoter | phosphate-repressible pPhoB promoter for toxin-antitoxin expression in response to phosphate. | Thierry Marti 2020 |
| BBa_K5283015 | P32 Promoter | Constitutive promoter | Drives constitutive expression of the Rep protein. | AFMU-China 2024 |
| BBa_K4586016 | CMV Promoter | Promoter for human cells | Eukaryotic promoter driving transgene expression in mammalian cells. | AFCM-Egypt iGEM team 2023 |
| BBa_K3113009 | L7Ae | Binding protein | RNA-binding protein that recognizes and binds C/D box RNA motifs. | Munich 2020 |
| BBa_25PH1CDU | DUF4811 | Transmembrane protein | Transmembrane anchoring domain for MV-RNA Loader localization. | AFCM-Egypt iGEM team 2025 |
| BBa_25MTVU1Q | Flexible Linker | CDS | Connects DUF and L7Ae domains without disrupting their function. | AFCM-Egypt iGEM team 2025 |
| BBa_25P1C1BV | LLO-L461T | pore-forming protein | An engineered listeriolysin for controlled endosomal escape with reduced pathogenic activity. | AFCM-Egypt iGEM team 2025 |
| BBa_K3257045 | LacR (Lac Repressor) | Repressor protein | Regulatory protein controlling Rep expression in response to pH signals. | Fudan-TSI 2019 |
| BBa_258JV9HJ | Rep Protein | Repressor protein | Repressor that keeps CO-BERA expression OFF under normal conditions. | AFCM-Egypt iGEM team 2025 |
| BBa_K1033259 | PemK-PemI | Toxin anti toxin | Toxin-antitoxin system ensuring biosafety and biocontainment. | Uppsala 2013 |
| BBa_250VF2PY | CO-BERA siRNA | Non coding RNA sequence | Therapeutic RNA designed to degrade TSLP mRNA and reduce inflammation. | AFCM-Egypt iGEM team 2025 |
| BBa_K4586023 | C/D Box RNA | Non coding RNA sequence | Structured RNA motif that binds L7Ae to stabilize siRNA packaging. | AFCM-Egypt iGEM team 2023 |
| BBa_K1993019 | T2A Peptide | Self-cleavage peptide | Self-cleaving peptide enables equimolar production of two proteins from one transcript. | SYSU-MEDICINE 2016 |
| BBa_25N36N7L | GFP | Reporter protein | Reporter protein for monitoring transcription and siRNA activity. | AFCM-Egypt iGEM team 2025 |
| BBa_25ONU8RD | TSLP Protein | Key cytokine for asthma | Target cytokine involved in asthma-related inflammation. | AFCM-Egypt iGEM team 2025 |
| BBa_K4094019 | SV40 PolyA Signal | Terminator for human cell line | Signals transcription termination and polyadenylation in mammalian cells. | Madison Hypes 2021 |
| BBa_K2789014 | rrnB T1 Terminator | Terminator | Ensures efficient transcription termination in prokaryotic systems. | Yifan Song 2018 |
| BBa_25LLOKGY | Kozak Sequence | CDS with start codon | Enhances translation initiation in mammalian systems. | AFCM-Egypt iGEM team 2025 |
| ID | Part Name | Short description | Designed |
|---|---|---|---|
| BBa_25BFTYLX | MV-RNA Loader (DUF-L7Ae) | Fusion protein combining DUF4811, Flexible Linker, and L7Ae. Anchors therapeutic siRNA to the bacterial membrane and packages it into membrane vesicles for delivery to lung epithelial cells. | AFCM-Egypt iGEM team 2025 |
| BBa_258L78SW | H₂O₂ and pH-Sensitive Endosomal Escape device | Encodes LLO-L461T, which is expressed in inflamed tissue in the presence of H₂O₂ to facilitate endosomal escape. Activated by acidic pH to form pores in endosomal membranes, releasing therapeutic siRNA into the cytoplasm. | AFCM-Egypt iGEM team 2025 |
| BBa_25B0FGPG | CO-BERA Expression Device (H₂O₂-Conditioned) | Produces CO-BERA siRNA in presence of H₂O₂, linking therapeutic output to oxidative stress. | AFCM-Egypt iGEM team 2025 |
| BBa_2591GLR1 | CO-BERA Expression Device (Constitutive) | Continuously produces CO-BERA siRNA under the control of a strong constitutive promoter (J23119). | AFCM-Egypt iGEM team 2025 |
| BBa_25FFH0AX | pH-Sensitive LacR Expression Device | Detects acidic pH via P170 promoter to express LacR, which regulates Rep protein activity and acts as a pH-sensitive ON/OFF switch. | AFCM-Egypt iGEM team 2025 |
| BBa_2575ZBSE | Rep Protein Expression Device | Produces the Rep protein under neutral pH to keep CO-BERA siRNA expression switched off until inflammatory conditions are detected. | AFCM-Egypt iGEM team 2025 |
| BBa_25S2FNDE | Therapeutic Action Device (CO-BERA siRNA) | Final therapeutic element where CO-BERA siRNA targets and degrades TSLP mRNA to reduce inflammation. | AFCM-Egypt iGEM team 2025 |
| BBa_25COZ8TM | Target Confirmation Device (human cell line) | Eukaryotic construct expressing GFP and TSLP using a T2A peptide. Measures the effectiveness of CO-BERA siRNA by monitoring GFP fluorescence. | AFCM-Egypt iGEM team 2025 |
| BBa_25DJB0M8 | Kill Switch (PemK-PemI System) | Ensures biosafety by killing the engineered bacterium if plasmid loss occurs, preventing survival outside the host or lab environment. | AFCM-Egypt iGEM team 2025 |
| New part ID | Old part ID | Part name | Description | Designer |
|---|---|---|---|---|
| BBa_25P1C1BV | BBa_K1897012 | LLO-L461T | In our project, we engineered the L461T mutant (LLO‑L461T). In contrast, another team (BBa_K1897013) used wild‑type LLO, which is activated only at acidic pH (late endosomes/lysosomes), but is associated with high cytotoxicity and pathogenicity. It has a high pathogenicity as it is a virulence factor of Listeria monocytogenes, and consequently, using it increases the pathogenicity of Listeria monocytogenes, so that we designed the Mutant LLO-L461T which retains pore-forming activity, but becomes active at a higher, near-neutral pH which means it triggers pore formation earlier, before RNA cargo is degraded, allowing rapid release of siRNA into the cytosol. Then we noted that the mutant LLO‑L461T still exerts strong cytotoxic effects, so we placed it under the control of the KatA promoter (an H₂O₂‑inducible promoter), which is activated only under conditions of oxidative stress when H₂O₂ is present. Thus, we place pathogenicity and cytotoxicity under control. In healthy tissue: no or low oxidative stress → LLO is not expressed → no unintended cytotoxicity. |
AFCM-Egypt iGEM team 2025
|
| Feature | wild-type LLO | Improved LLO-L461T |
|---|---|---|
| Activation | Acidic (low pH only) | Near-neutral pH → faster therapeutic release |
| Cytotoxicity | High | Reduced (controlled by the KatA promoter) |
| Regulation | Unregulated (always produced when expressed) | Controlled by H₂O₂ via KatA promoter |
| Safety | Lower | Significantly higher due to dual control |
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