Figure 2.

Plk1 and Bora remain in a complex during the initial stages of the DDR. (a) U2OS cells were synchronized by thymidine, released for 7 h in G2 and treated for 1 h with 0.5 μM adriamycin. Cells remained arrested for 16 h and recovery was induced by addition of caffeine. During caffeine treatment, cells were co-treated with the indicated inhibitors. Plk1 was immunoprecipitated and protein levels were analyzed by western blotting. (b) U2OS cells were synchronized by thymidine and released into G2 for 8 h. Where indicated, cells were treated with 1 h 0.5 μM adriamycin or 10 μM etoposide and collected after a total of 11 h after thymidne release or for 3 h with 4 μM RO 3306. Plk1 was immunoprecipitated and protein levels were analyzed by western blotting. (c) U2OS cells were released after thymidine release (TR) at the indicated times and treated with the indicated types of DNA damage (0.5 μM adriamycin 10 μM etoposide or 10 Gy of ionizing irradiation (IR)). Plk1 was immunprecipitated and samples were probed with the indicated antibodies.