FIG 7.

JCV DNA replication in G144 cells is reduced by a derivative of pFL-JCVori containing mutations at the nfi a and b binding sites. (A) Depiction of the Mad-1 enhancer showing the relative locations of the nfi a and b binding sites (magenta). (B) Luciferase-based replication assays conducted in undifferentiated G144 cells for 72 and 96 h comparing levels of JCV DNA replication obtained with the wt Mad-1 enhancer and a Mad-1 derivative containing mutant nfi a and b binding sites. Means (n = 3) are reported, and the error bars indicate standard deviations from the mean. The asterisks indicate significant increases in JC replication (P < 0.05) compared with reactions performed in the absence of T-ag (−). (C) Western blots establishing the relative levels of the NFI family members in undifferentiated G144 cells. Vinculin levels were determined as loading controls. (D) Results of JCV DNA replication assays conducted in differentiated G144 cells for 72 and 96 h. As in panel B, levels of JCV DNA replication obtained with the Mad-1 enhancer containing mutant nfi a and b binding sites were greatly reduced relative to the wt Mad-1 enhancer. (E) Western blots establishing the relative levels of the NFI family members in differentiated G144 cells; vinculin levels were determined as loading controls.