FIG. 5.

MdmX maintains nuclear pools of p53 and blocks p53 transactivation. H1299 cells were transfected with 0.25 μg of CMVp53 (lanes 2 to 8), 0.75 μg of CMVmdm2 (lanes 4 to 8), and 5.25 μg of CMVmdmX, CMVmdmXΔp53, CMVLacZ, or CMVmdm2ΔRF. Each transfection also contained 0.5 μg of pGL3Luc and 1 μg of the indicated reporter plasmid. Cell extracts were prepared 24 h after transfection, and equal luciferase units were analyzed via Western analysis (A) or CAT assay (B). Error bars represent difference between duplicates of the same extracts. Similar results have been observed in three independent experiments.