规格
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Cloning Method:
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Restriction Enzyme ⁄ MCS |
Key Functions:
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Regulated Expression |
Product Line:
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GeneSwitch™ |
Constitutive or Inducible System:
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Inducible |
Delivery Type:
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Transfection |
Inducing Agent:
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Mifepristone |
Promoter:
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E1b (GAL4-E1b) |
Selection Agent (Eukaryotic):
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Zeocin™ |
Vector:
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pGene |
Protein Tag:
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His Tag (6x), V5 Epitope Tag |
储存
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The GeneSwitch™ System Core Kit includes 20 µg of each of the following vectors: pGene/V5-His (A, B, and C), the expression control vector pGene/V5-His/lacZ, and the pSwitch vector. The kit also includes forward and reverse sequencing primers and 100 µg of the inducing agent mifepristone. The GeneSwitch™ Complete Kit includes the Core Kit with 1 g hygromycin and 1 g Zeocin™ at considerable savings. Hygromycin should be stored at +4°C and Zeocin™ at -20°C. Zeocin™ should be protected from exposure to light. All reagents are stable for 6 months when properly stored. |
Switch-On Expression from the Lowest Basal Levels
The GeneSwitch™ System for inducible mammalian expression is ideal for experiments that require the absolute lowest uninduced expression levels. The expression vector pGene/V5-His provides a minimal promoter, GAL4-E1b, consisting of the binding sites for the yeast Gal4 DNA binding protein followed by the TATA sequence from the Adenovirus E1b promoter. Without additional factors, the GAL4-E1b promoter is transcriptionally silent.
To activate transcription from the GAL4-E1b promoter, the GeneSwitch™ regulatory protein is expressed from a minimal TK promoter on the pSwitch vector. The GeneSwitch™ protein has three functional domains:
• Gal4 DNA Binding Domain (Gal4-DBD) to bind the regulatory protein to the GAL4-E1b promoter
• Truncated human Progesterone Receptor Ligand Binding Domain (hPR-LBD) that undergoes a conformational change when it binds the progesterone antagonist, mifepristone
• Transcription activation domain from the NFØB transcription factor p65 (p65AD) to activate transcription from the silent GAL4-E1b promoter
In the absence of mifepristone, the conformation of the hPR-LBD region prevents the GeneSwitch™ regulatory protein from activating transcription from the GAL4-E1b promoter. When mifepristone is added and binds the hPR-LBD region, the GeneSwitch™ regulatory protein assumes a conformation that permits it to stimulate transcription from the GAL4-E1b promoter (Figures 1 and 2).
Induction of the GeneSwitch™ System leads to activation of the gene of interest on the vector pGene/V5-His. In addition, four Gal4 binding sites upstream of the minimal HSV TK promoter on pSwitch can bind the pSwitch regulatory protein. Therefore, adding mifepristone up-regulates production of the regulatory protein (Figure 1). The increased levels of the GeneSwitch™ regulatory protein result in induction of the gene of interest from pGene/V5-His to levels that can approach those of viral promoters.
The GeneSwitch™ Kit offers exceptionally low uninduced and high induced expression levels in mammalian cells. The system provides the expression vector pGene/V5-His with the minimal, synthetic GAL4-E1b promoter that is transcriptionally silent until activated. The GeneSwitch™ regulatory protein binds the GAL4-E1b promoter to activate transcription upon the addition of mifepristone. In addition, the GeneSwitch™ protein upregulates its own expression, leading to amplified expression of the gene of interest from pGene/V5-His. pGene/V5-His offers several features that facilitate expression analysis and purification of recombinant proteins in mammalian cells:
• C-terminal V5 epitope tag for detection with Anti-V5 Antibodies
• C-terminal polyhistidine (6xHis) tag for rapid purification with nickel-chelating resin and detection with Anti-His(C-term) Antibodies
• The Zeocin™ resistance gene for effective selection in both mammalian cells and E. coli