SV40 early region promoter (Psv)

[Monique]

What exactly is this promoter? As I understand it, it will only drive gene expression when you add an enhancer to it?

 

[detta]

The SV40 promoter is a promoter from the SV40 virus DNA. From its origin of replication it can transcribe either early or late genes. The early region mRNA codes for the Large and Small Tumor Antigen Proteins. Large T antigen binds DNA and acts like a helicase, recruiting the machinery needed to duplicate DNA. It binds the GAGGC in the SV40 origin and allows the virus to replicate. This is self regulated to cause DNA replication once per cell cycle because it needs DNA replication machinery from the cell to replicate. The late region is expressed later in time because it encodes the capsid proteins and is only needed when the virus is replicated and needs to encapsulate and leave the cell to infect other cells.
I'm not sure what the enhancer is but it most likely is a host cell protein.

 

[quetzalcoatl9]

monique, are you using a new plasmid?

the ones I've used usually had both CMV and SV40 ori and promoters all over the place (for fluresence microscopy). The CMV promoter would point to the MCS, (GFP sequence before the MCS)and then followed by the SV40 poly A tail. The SV40 e promoter would point to the Kan/Neo resistance gene, follwed by HSV poly A and an optional thymidine kinase for double-selection/homologous recombination. I image there are many variations on this.

It is interesting to note that the T antigen of SV40 will immortalize a human cell. Infact, I have used such a transformed cell line (SVG).