FIG. 7.

Functional interaction of two Agno protein deletion mutants with T antigen. (A and B) Effect of Agno protein deletion mutants on T-antigen-mediated transcriptional activation of JCV late promoter. A CAT reporter plasmid (pBLCAT₃-Mad-1L) (7 μg) containing the JCV late promoter was transfected into U-87MG cells alone or in combination with Agno protein deletion mutants Agno(1-36) (A) and Agno(55-71) (B) and T-antigen expression plasmids. The concentrations of expression plasmids are indicated at the bottom of the respective panels in micrograms. A representative CAT assay for each panel is shown on the top. The results shown in each panel represent the mean of three independent experiments. (C and D) Effect of Agno protein mutants on T-antigen-mediated JCV DNA replication. A replication-competent plasmid, pBLCAT₃-Mad-1L (5 μg), containing the regulatory region of the Mad-1 strain of JCV, was transfected alone or in combination with Agno protein deletion mutants CMV-Agno(1-36) (C) and CMV-Agno(55-71) (D) and CMV-T-antigen expression plasmids into U-87MG cells. Plasmid concentrations used in transfections are indicated on top in micrograms. The total amount of DNA transfected into the cells was normalized with appropriate empty vectors. Replication assays were carried out as described for Fig. 3. The replicated DNA is indicated by an arrow and input DNA is indicated by a bracket. The quantitation of the bands corresponding to the replicated viral DNA was carried out as described for Fig. 3.