It is known that 293T constitutively express SV40 large T antigen, which can bind to SV40 enhancers. Does that mean that SV40 promoter is the best promoter in 293T cell?
The most popular mammalian expression vectors use CMV promoter and it works very well in HEK293T cells. I usually need to titrate down the expression level for a physiological response in HEK293T cells with those constructs in reverse transfection. It may be not the best, but the CMV promoter is pretty strong already.
The SV40 promoter is fairly weak in 293T cells compared to the CMV promoter. So for the highest expression, For the highest protein "overexpression", I use a vector with the CMV promoter and the SV40 ori so that the large T antigen can replicate the plasmid in the 293T cells and increase expression.
Hi
My suggestion is that you think more of the strength of expression that you want to give to your transgene. If you check the paper on the link I'm attaching, they compared a series of common promoters in different cell lines. For 293Ts CMV would be the strongest, SV40 would be a medium expression and UBC or PGK would give you a low expression. In my experiments I want my protein to be weakly expressed and I use PGK. It works well in 293T cells.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0010611
Again, I suggest that you think on what is your aim with the transgene you want to express.
- Badges
- Science topic
- Similar topics
- Biological Science
- Molecular Cell Biology