BRCA1/BARD1 downregulation prevents recruitment of these proteins along with Rad51 to chromatin following MMS treatment. Hammond-MartelIan PakHelen YuHelen RougetRaphael A. HorwitzAndrew D. ParvinJeffrey A. DrobetskyElliot Bachir AffarEl 2010 <p>A) HeLa cells were treated for 6 hrs with IR (10 Gy) or 200 µM MMS (with or without pretreatment with MG132). Chromatin from control or treated cells was prepared as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0014027#s4" target="_blank">material and methods</a> and proteins were detected by western blotting. Histones were stained with coomassie blue to ensure equal loading. B) HeLa cells were treated as in panel A and harvested for immunostaining (<i>left panel</i>). Cells with more than 10 foci were counted and the data are presented as percentage of cells with foci under each condition (<i>right panel</i>). The values represent the average ± SD of three independent experiments. C) HeLa cells were treated as in A except that a permeabilization step was added before fixation and immunostaining (<i>left panel</i>). Cells with more than 10 foci were counted and the data are presented as percentage of cells with foci under each condition (<i>right panel</i>). The values represent the average ± SD of three independent experiments.</p>