Sv40Ori acts as a promoter?

[oikari at hytti.uku.fi]

Greets,

I do have strange pUC119 -based plasmid with Sv40Ori and Human elongation
factor 1 alpha -promoter in sequence behind each other (Sv40Ori+Ef1a-GFP)

When I cloned Ef1a as a promoter into the pcDNA3 (removing CMV) expression
of GFP dropped dramatically compared to pUC119 -based vector.

Both plasmids are roughly 10kb, and were transfected into Cos-7 cells
using standard CaCl precipitation method.

So the question is that if Sv40Ori can enhance expression as a "second"
promoter (or is there something on pcDNA3 that blocks expression)?
Any test, results or thoughts available?

Thanks

P.Oikari

-------------------==== Posted via Deja News ====-----------------------
      http://www.dejanews.com/     Search, Read, Post to Usenet