Figure 1.

Inverse correlation between pS824-KAP1 foci and RNF4 abundance. (A) pS824-KAP1 foci are mainly present in cyclin A (-) cells. Co-staining of pS824-KAP1 and cyclin A in cycling MCF7 cells at 1-h post-IR (4 Gy). The foci were visualized with immunofluorescence (IF) microscopy using indicated antibodies and DAPI. Scale bar: 10 μm. (B) pS824-KAP1 is abundantly present in G0-/G1-phases, but not in S-/G2-phases. MCF7 cells were synchronized and then irradiated as indicated. Upper panel: Western blot analyses were performed to assess the abundance of indicated proteins. Lower panel: cell cycle analyses of synchronous cells. Numbers represent the percentage of cells in each cell cycle phase. Asy: asynchronous; SS: serum starvation; APH, 4h: release from aphidicolin treatment for 4-h. (C) RNF4 abundance is regulated during cell cycle progression. MCF7 cells were synchronized by serum starvation and then released as indicated. Upper panel: RNF4 abundance was assessed by Western blot analysis. Lower panel: cell cycle analyses of synchronous cells. Numbers represent the percentage of cells in each cell cycle phase. (D) Dynamic level of RNF4 at different stages of cell cycle. MCF7 cells were synchronized at different stages of cell cycle as indicated. Western blot analyses were used to assess the abundance of the indicated proteins. (B-D) N = 3, representative blots were shown.