What is tetracycline-inducible?

Published by Anaya Cole on

What is tetracycline-inducible?

The Tet system is a conditional gene expression system where transcription is turned on or off in the presence of tetracycline or doxycycline. It affords very tight control over expression compared to other inducible systems and is reversible.

What is a Tet promoter?

The TRE is made up of Tet operator (tetO) sequence concatemers fused to a minimal promoter, (commonly the minimal promoter sequence derived from the human cytomegalovirus (hCMV) immediate-early promoter). In the absence of Tc or Dox, tTA binds to the TRE and activates transcription of the target gene.

How does Tet on system work?

Tet-Off system: tetracycline prevents the tTA transcription factor from binding DNA at the promoter. Gene expression is inhibited in the presence of tetracycline. Tet-On system: tetracycline binds the rtTA transcription factor and allows it to bind DNA at the promoter.

What is TET3G?

This system is based on two components: the Tet transactivator (TET3G), a protein that structurally responds to Dox, and the Tet-binding promoter upstream of the GOI.

What is a tet operator?

How does Tet repressor work?

TetR represses the expression of TetA, a membrane protein that pumps out substances toxic to the bacteria like Tc, by binding the tetA operator. In Tc-resistant bacteria, TetA will pump out Tc before it can bind to the ribosome because the repressive action of TetR on TetA is halted by binding of Tc to TetR.

What is Tet On and Tet-Off system?

The Tet-Off and Tet-On expression systems are binary transgenic systems in which expression from a target transgene is dependent on the activity of an inducible transcriptional activator.

What is the tac promoter and how is it regulated?

The tac promoter is used to control and increase the expression levels of a target gene and is used in the over-expression of recombinant proteins. The tac promoter is named after the two promoters which comprise its sequence: the ‘trp’ and the ‘lac’ promoters.

What is inducible and repressible operon?

Some operons are inducible, meaning that they can be turned on by the presence of a particular small molecule. Others are repressible, meaning that they are on by default but can be turned off by a small molecule.

What are Tet on cells?

Tet-Off cell lines are host cell lines that greatly simplify the task of setting up a tetracycline-inducible gene expression system that is activated by removing doxycycline (Dox) from the culture medium.

What is tetracycline resistance gene?

The tet(W) tetracycline resistance gene encodes a protection protein that attaches to the ribosome and causes an alteration of the ribosomal conformation to which tetracycline cannot bind and therefore protein synthesis can proceed (Chopra and Roberts, 2001; Connell et al., 2003).

What does Tet on mean?

The tetracycline-controlled Tet-Off and Tet-On gene expression systems are used to regulate the activity of genes in eukaryotic cells in diverse settings, varying from basic biological research to biotechnology and gene therapy applications.

How does the Tet promoter work?

Can activator/repressor expression be controlled by tetracyclines?

We have developed an activator/repressor expression system for budding yeast in which tetracyclines control in opposite ways the ability of tetR-based activator and repressor molecules to bind tetO promoters.

Is tetracycline a hybrid transactivator?

In the presence of tetracycline, tetracycline binds to tetR. This precludes tTA binding to the tetO sequences and subsequent increase in expression by the activation domain, resulting in reduced gene expression. This idea of a hybrid transactivator was initially used with the lac system. Tetracycline off is also known as the tTA-dependent system.

How does tetracycline affect the function of the activation domain?

In the absence of tetracycline, the tetR portion of tTA will bind these tetO sequences and the activation domain promotes expression. In the presence of tetracycline, tetracycline binds to tetR. This precludes tTA binding to the tetO sequences and subsequent increase in expression by the activation domain, resulting in reduced gene expression.

What are the components of a tetracycline on system?

Components for a tetracycline on system are: Plasmid containing a tetracycline-dependent promoter upstream of your gene of interest rtTA or TetR expression plasmid Stable cell lines can be made that continuously express a system component (e.g. tTA).

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