Regulation of TRAF6 polyubiquitination by OPTN.
A, HEK293T cells were transfected with FLAG-tagged TRAF6 and HA-tagged ubiquitin with or without Myc-tagged OPTN. After 36 h of transfection, immunoprecipitation (IP) was performed using anti-FLAG antibody. Then Western blotting (WB) was performed using anti-FLAG, anti-HA, or anti-Myc antibody. Data are representative of three independent experiments with similar results. B, relative polyubiquitination level of TRAF6 in OPTN-transfected HEK293T cells. Data are the mean ± SD of three independent experiments and are presented relative to the vector-transfected control cells, set as 1. *, p < 0.05.