FIG 3.

RNF126 promotes IR-dependent degradation of Ku80 and Ku70 associated with chromatin. (A) U2OS cells were exposed (or left unexposed) to IR (2 Gy), incubated with cycloheximide (50 μg/ml) in the absence or presence of 10 μM MG132 (MG) for the indicated times, and then subjected to subcellular fractionation. Soluble and chromatin fractions were subjected to immunoblot analysis with antibodies to the indicated proteins. The relative amounts of Ku80 and Ku70 normalized by that of tubulin or histone H3 (HH3) at each time point were determined by measurement of band intensity. (B) U2OS cells transfected with RNF126 (siRNF) or control (siCtrl) siRNAs for 48 h were exposed to IR (2 Gy), incubated with cycloheximide for the indicated times, and then analyzed as described for panel A.