Figure 7. Mdm2 interacts with the p53 isoforms. 1μg of relevant p53 isoform (as indicated) was co-expressed with 1μg Mdm2 in H1299 cells. Three hours prior to harvesting, all cells were treated with MG132. Cells were lysed under native conditions and then split for immunoprecipitation with anti-Mdm2 antibody or IgG isotype control antibody, as indicated. Co-immunoprecipitations are shown in the left panel and the inputs in the right panel. *Denotes molecular weight of light chain, and closed arrowhead indicates Δ133p53β and Δ133p53γ isoforms.