USP7 interacts with TRAF6 and IKKγ. (A) 293-TLR4 cells expressing pcDNA3.2-capTEV-USP7 were LPS-stimulated at different time points (0, 15, and 30 minutes) before they were lysed by freeze-thaw, TAP-purified, and blotted with anti-USP7, anti-TRAF6, and anti-IKKγ. Data are representative of 2 experiments. (B) THP1 cells were LPS-stimulated at different time points (0, 15, 30, and 60 minutes) before endogenous TRAF6 and IKKγ were immunoprecipitated and blotted with anti-USP7. (C) ICP0 enhances USP7 binding to endogenous TRAF6 and IKKγ: 293T cells were transfected with ICP0 and USP7 either alone or in combination and 24 hours later endogenous TRAF6 and IKKγ were immunoprecipitated and blotted with anti-USP7. Expression of ICP0 significantly enhanced USP7 binding to endogenous TRAF6 and IKKγ. (D) HEK293-TLR4 cells were transfected with Myc-tagged USP7-FL (1-1102), USP7-TD (1-210), or USP7.ΔTD (210-1102), stimulated with LPS for 1 hour, and then lysed and endogenous TRAF6 and IKKγ were immunoprecipitated. Immunoprecipitated TRAF6 and IKKγ bound both USP7-FL (1-1102) and USP7-TD (1-210).