Figure 4.
Interactions between Rad51 paralogs in Ni2+ pull-down experiments are unaffected by DNA damage. (A) WTK1-Rad51C and TK6-XRCC3 cells were treated with 10 Gy X-ray and protein extracts (same as used in Fig. 2) were used in Ni2+ pull-down experiments. In the first three lanes, Rad51C-(His)6 is pulled down, and in the last three lanes, XRCC3-(His)6 is pulled down. (B) Treatment of TK6-XRCC3 with MMC (0.5 µg/ml for 4 h) does not affect the interaction of Rad51C with XRCC3-(His)6. In the first lane, Rad51C-(His)6 is pulled down, and in the last two lanes, XRCC3-(His)6 is pulled down. TK6 was the negative control in the top panel and WTK1 was used as a negative control in the bottom panel (second lane in each case). Please note that the upper part of (B) was probed with a monoclonal antibody against Rad51C, and this antibody does not recognize the recombinant form of Rad51C-(His)6. This is very probably due to the interference of the His6-tag with the C-terminally directed epitope of this antibody.