Figure 6(A) Immunoprecipitation analysis of HEK293T cells transfected with Flag-SQSTM1 or its I431A mutant together with HA-MAVS. Anti-Flag or IgG agarose immunoprecipitates were analyzed using immunoblotting with an anti-HA or anti-Flag antibody. Cell-based studies were performed independently at least three times with comparable results.(B) Luciferase activity driven by the IFN-β promoter in HEK293T cells transfected with HA-MAVS or its 4KR mutant together with Flag-SQSTM1 or its I431A mutant. Luciferase assays were performed 24 hrs after transfection. The luciferase reporter data are presented as means ± SEM. Two-tailed Student's t-tests were used for statistical analyses: *, P < 0.05; **, P < 0.01; and ***, P < 0.001.(C) Immunoblot showing the levels of the MAVS protein in HEK293T cells expressing HA-MAVS or its 4KR mutant together with Flag-SQSTM1. α-Tubulin was used as a loading control. Cell-based studies were performed independently at least three times with comparable results.(D) Luciferase activity driven by the IFN-β promoter in HEK293T cells transfected with HA-MAVS or its 4KR mutant together with Flag-NDP52 or its D439R/C443K mutant. Luciferase assays were performed 24 hrs after transfection. The luciferase reporter data are presented as means ± SEM. Two-tailed Student's t-tests were used for statistical analyses: *, P < 0.05; **, P < 0.01; and ***, P < 0.001.(E) Immunoprecipitation analysis of HEK293T cells transfected with Flag-MAVS or its 4KR mutant together with Myc-NDP52. Anti-Flag immunoprecipitates were analyzed using immunoblotting with an anti-Myc or anti-Flag antibody. Cell-based studies were performed independently at least three times with comparable results.(F) Immunoprecipitation analysis of the DNP52-RNF34 interaction in cells infected with VSV. Anti-DNP52 immunoprecipitates were analyzed using immunoblotting with an anti-DNP52 or anti-RNF34 antibody. The WCL was immunoblotted with an anti-MAVS or anti- RNF34 antibody. Cell-based studies were performed independently at least three times with comparable results.(G) Immunoprecipitation analysis of the interaction between Flag-NDP52 and HA-RNF34 in WT or MAVS-/- cells. Anti-Flag immunoprecipitates were analyzed using immunoblotting with an anti-HA antibody. Cell-based studies were performed independently at least three times with comparable results.(H) Immunoprecipitation analysis of HEK293T cells transfected with Flag-NDP52 or its D439R/C443K mutant together with HA-MAVS followed by VSV infection. Anti-Flag immunoprecipitates were analyzed using immunoblotting with an anti-HA or anti-Flag antibody. Cell-based studies were performed independently at least three times with comparable results.(I) Immunoblot showing the levels of the MAVS protein in siCtrl- or siNDP52-transfected cells expressing Flag-RNF34 or Flag-V. α-Tubulin was used as a loading control. Cell-based studies were performed independently at least three times with comparable results.(J) Immunoblot showing the levels of the MAVS protein in siCtrl- or siNDP52-transfected cells infected with VSV (MOI = 1, 12 hrs). α-Tubulin was used as a loading control. Cell-based studies were performed independently at least three times with comparable results.(K) Immunoprecipitation analysis of the MAVS-LC3 interaction in siCtrl- or siNDP52-transfected cells infected with VSV. Anti-MAVS immunoprecipitates were analyzed using immunoblotting with an anti-MAVS or anti-LC3 antibody. NDP52 levels were analyzed by performing immunoblotting with an anti-NDP52 antibody. α-Tubulin was used as a loading control. Cell-based studies were performed independently at least three times with comparable results.