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Team:LMU-Munich/TEV-System/Functional Principle
From 2010.igem.org
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== TEVdegron-System == | == TEVdegron-System == | ||
| - | The TEVdegron-System uses and cobines several proteins with different properties. We need two DNA constructs and one of them (construct 1) should be integrated in the cell's DNA. | + | The TEVdegron-System uses and cobines several proteins with different properties to select the icorporation of a plasmid by apoptosis. We need two DNA constructs and one of them (construct 1) should be integrated in the cell's DNA. |
=== Construct 1 === | === Construct 1 === | ||
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==== Case b) the plasmid has been incorporated ==== | ==== Case b) the plasmid has been incorporated ==== | ||
| - | Construct 2 will | + | Construct 2 will be read off and and already existing when tet-on promoter will be induced to create construct 1 as protein. Therefore TEV proteases will instantly seperate eGFP from the remain of the protein an will free the N-terminus of N-degron. This will cause the degradation of the whole protein complex - including bak. So only the gene of interest and the whole cell will "survive". |
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| + | [[Image:TEV4.jpg|400pxs|TEVdegron-System: TEV-degron-System]] | ||
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| + | So you can see that cells that incorporated the plasmid will survive. | ||
{{:Team:LMU-Munich/Templates/Page Footer}} | {{:Team:LMU-Munich/Templates/Page Footer}} | ||
Revision as of 19:36, 15 August 2010
second try:
The TEVdegron-System uses and cobines several proteins with different properties to select the icorporation of a plasmid by apoptosis. We need two DNA constructs and one of them (construct 1) should be integrated in the cell's DNA.
Construct 1 contains the following parts in this order:
CMV-promoter for the hygromycin resistance, hygromycin resistance, tetracyclin-inducible promoter, TEV-recognition site, N-degron, SF3b155, human bak.
To check the integration of tis construct into cellular DNA we need the hygromycin resistance which can be read-off thanks to the CMV-promoter. The TEV-recognition site will be cut by the TEV-protease which is part of construct 2. Due to the serration of TEV-recognition site the N-terminus of N-degron is free which is a signal for the degeneration of this protein. SF3b155 is a protein interacting with p14 from construct 2. This interaction should make sure that the TEV-protease of construct 2 will really "find" the recognition site. The human bak is a apoptosis triggering membrane protein.
Construct 2 is composed of CMV-promoter, TEV-protease, p14, TEV-recognition site, eGFP and a double stop codon.
The CMV-promoter is to read off construct 2. The task of TEV-protease is to cut TEV-recognition sites, espacially the one ahead of N-degron to signal protein degradation. p14 is interacting with SF3b155 and so increases the rate of TEV-proteases which "find" a TEV-recognition site. eGFP is our example of a gene of interest which can be verified by green flourescence.
So you have a cellline which has integrated construct 1 and transfect it with a plasmid containing construct 2. Then there are two possibilities:
a) the plasmid has not been incorporated
b) the plasmid has been incorporated
which leads to the following consequences.
We induce the tet-on promoter and so construct 1 will be translated into protein. The bak-part will integrate into mitochondrial membrane and as a result will induce apoptosis.
Construct 2 will be read off and and already existing when tet-on promoter will be induced to create construct 1 as protein. Therefore TEV proteases will instantly seperate eGFP from the remain of the protein an will free the N-terminus of N-degron. This will cause the degradation of the whole protein complex - including bak. So only the gene of interest and the whole cell will "survive".
If one has the Cellline which is stable transformed with TetinduciblePromoter+TEVrecognition+Ndegron+SF3B+bak one can transform these cells with the Construct containing the Protein of interest.
If the plasmid has been incorporated by the cell, both protein complexes should be synthesized when the Tet inducible Promoter is induzed by doxycyclin.
Both protein-complexes are supposed to attach because p14* and SF3B are interacting proteins.
The TEV-protease is supposed to cut the recognition sites. Now the protein of interest (eGFP) is split apart and the N-terminus of the N-degron is uncovered. This is a signal for the cell to deplete the protein complex including the deadly bak. So all protein should be destroyed except the protein of interest.
If no plasmid has been incorporated, the cell will die because of Bak.
Contents
TEVdegron-System
Construct 1
Construct 2
Selection
Case a) the plasmid has not been incorporated
Case b) the plasmid has been incorporated
So you can see that cells that incorporated the plasmid will survive.
