MPA induces c-Jun, c-Fos and PR nuclear colocalization and physical association. (A) PR, c-Jun and c-Fos were localized by IF and confocal microscopy. Merged images show MPA-induced c-Jun/PR or c-Fos/PR nuclear colocalization, evidenced by the yellow foci. Boxed areas are shown in detail in the right insets. Nuclei were stained with DAPI (blue). (B) PR/c-Jun and PR/-c-Fos nuclear interactions were detected by in situ PLA. The detected dimers are shown by the fluorescent rolling circle products (red). Nuclei were stained with DAPI (blue). The experiments shown were repeated three times with similar results. See also Additional file 1: Figure 2. MPA, Medroxyprogesterone acetate; PLA, Proximity ligation assay; PR, Progesterone receptor.