Figure 6.

The critical function of TRAF2 in TIFA-mediated NEMO ubiquitination. a, the extracts from cells stably expressing control vector or FLAG-TIFA in the absence or presence of ETO were immunoprecipitated (IP) with FLAG M2 resin and eluted with FLAG peptide. Silver stain and mass spectrometric analysis were performed as described in the legend to Fig. 5a. b, the HeLa cells were co-transfected with FLAG-NEMO, HA-Ub, EGFP-TIFA, and TRAF2 as indicated. All cells were treated with ETO before cellular extracts were prepared. The immunoprecipitation was performed with FLAG antibody and the immunoprecipitated proteins were examined with HA antibody. c, the HeLa cells transfected with the indicated plasmids were further co-transfected with siRNA control or siRNA targeting TRAF2. All cells were treated with ETO before cellular extracts were prepared. The immunoprecipitation was performed as in b.