tetracyclin inducible system

Display Systems Biotech dissyst at primenet.com
Wed Feb 21 19:47:02 EST 1996

Display Systems Biotech have the below system, if that's what you are looking 
for I am sure you can get a copy of the protocols. Contact 1 800 697 1111 or 
e-mail dissyst at primenet.com

The Tetracycline controlled system for regulation of eukaryotic gene 
Since the publication of the tTA-dependent expression system (1) many 
researchers have started to establish the system in tissue culture or transgenic 
animals; Display Systems Biotechnology  introduces the tetracycline gene 
expression module - a system based on transfection of two plasmids into cell 
Plasmid one constitutively express a fusion protein tTA consisting of the trans 
activation domain of the herpes simplex virus virion protein 16 (VP16) fused to 
a bacterial tetracycline resistance gene (tet) repressor. In Escherichia coli the tet 
repressor binds to a specific recognition sequence in the tet operator (tetO) of 
Tn10 in absence of tetracycline, however in the presence of tetracycline it binds 
to the drug and thereby allows transcription of the tet genes (2).
Plasmid two contains a heptamirized upstream binding site of the tet operator 
(tetO), downstream of which a minimal cytomegalovirus was inserted (1), the 
cDNA of interest is placed downstream of this operator/promotor element, thus 
allowing tetracycline-regulated expression of the desired gene product (1).
The minimal (enhancerless) promotor is silent in the absence of tTA binding i.e., 
presence of tetracycline in the culture medium. However, if the tetracycline is 
removed from the culture medium the tet repressor binds strongly to the 
heptamirized binding site, thus allowing the VP16 part of the chimeric protein 
tTA to activate transcription of the cDNA of interest.

Thomas W. Jenkins

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