Figure 3. siRNA knockdown of DNA-PKcs abrogates IR-induced PP6R1 nuclear localization.

A. M059K cells were transfected with control siRNA or anti-DNA-PKcs siRNA, and 48 hours later subjected to 5 Gy. One hour post-irradiation, the cells were fixed and immunostained with anti-DNA-PKcs and PP6R1 antibodies. Upper row: orange PP6R1 and lower row: merged Dapi ,DNA-PK and PP6R1. B. M059K cells were transfected with control siRNA or anti-DNA-PKcs siRNA and subjected to irradiation 48 hours post –transfection. One hour post-irradiation the cells were fractionated into cytoplasmic and nuclear fractions. The protein levels of DNA-PKcs, PP6R1, and Ku were detected by immunoblotting.