Figure 4. p62 interacts with ECSIT. (A) HEK293T cells were transfected with mock, Flag-ECSIT WT, and Flag-ECSIT truncated mutants, Flag-ECSIT 1-300 and Flag-ECSIT 1-200, and Myc-p62, as indicated. At 38 h post transfection, the transfected cells were extracted and the cell lysates were subjected to immunoprecipitation with anti-Myc antibody followed by IB using anti-Flag or anti-Myc antibody. Model of how p62 interacts with ECSIT (down). (B) HEK293T cells were transfected with mock, Myc-p62, Flag-TRAF6 WT, and Flag-TRAF6 truncated mutants, Flag-TRAF6 110-522, Flag-TRAF6 260-522, and Flag-TRAF6 349-522, as indicated. At 38 h post transfection, transfected cells were extracted and cell lysates were subjected to immunoprecipitation with anti-Flag antibody followed by IB using anti-Flag or anti-Myc antibody. Model of how p62 interacts with TRAF6 (down). (C) Model of how ECSIT interacts with TRAF6 and p62. (D) A possible model in which p62 is negatively implicated in TRAF6/ECSIT-mediated activation of NF-κB.