Figure 7.

HFE interaction with SQSTM1 facilitates MAVS autophagic degradation. (A) HFE interaction with SQSTM1 but not CALCOCO2, NBR1, NIX, TOLLIP and OPTN. HEK293T cells were transfected with vectors encoding MYC-HFE and indicated Flag-tagged cargo receptors, followed by co-immunoprecipitation with anti-FLAG antibody and immunoblot analysis with anti-MYC antibody. (B and C) MAVS degradation via SQSTM1. WT and SQSTM1 KO (^−/-) 293 T cells were transfected with only MYC-HFE or FLAG-MAVS and MYC-HFE plasmids. Cell lysates were subjected to immunoblot analysis. (D) Luciferase assay of IFNB1 or ISRE. HEK293T WT and SQSTM1 KO cells were co-transfected with the IFNB1 or ISRE reporter plasmid together with MAVS in the presence or absence of HFE plasmid. Data are representative of at least three independent experiments, and differences between the experimental and control groups are determined by 2-way ANOVA (**p < 0.01, ***p < 0.001). (E) A proposed working model to illustrate how HFE negatively regulates type I IFNs signaling during RNA virus infection