Use of Poliovirus cDNA 5′NCR Together with Its Polymerase Gene Can Increase Foreign Gene Expression
The four plasmids containing different length of RNA polymerase gene of poliovirus were constructed to express RNA polymerase. By enzymatic assays, it indicated that two of these four plasmids,pSG5 POL1.99 and pSG5 POL2.03,could express RNA polymerase. Poliovirus cDNA 5′NCR was inserted between CMV promoter and report gene GFP or LacZ of plasmid pGREEN LANTERN 1 or pLacZ LANTERN 1 respectively. The expression of report genes was obviously increased only by cotransfection with the plasmid expressing PV RNA polymerase and the plasmid in which the expression of report gene is regulated by PV 5′NCR. The result above indicated that high expression vector could be constructed by using both of PV 5′NCR and RNA polymerase gene.