Supplementary Figure 5: TRIM31 catalyzes K63-linked polyubiquitination of MAVS.

(a) Coimmunoprecipitation analysis of RIG-I ubiquitination in HEK293T cells transfected with Myc-RIG-I and HA-Ubiquitin together with control plasmid, Flag-TRIM31 plasmid or Flag-TRIM25 plasmid. (b) Luciferase activity in HEK293T cells transfected with IFNB1 luciferase reporter or ISRE luciferase reporter together with Flag-TRIM31-WT plasmid or Flag-TRIM31-C53/56A plasmid for 24 h followed with SeV infection for indicated times. (c) qPCR analysis of IFNB1 mRNA and VSV RNA in HEK293T cells transfected with control plasmid, Flag-TRIM31-WT plasmid or Flag-TRIM31-C53/56A plasmid for 24 h followed with VSV infection (MOI, 0.1) for indicated times. mRNA results are presented relative to those of untreated cells transfected with control plasmid. (d) Immunoblot of phosphorylated and total IRF3 protein in lysates of HEK293T cells transfected with Flag-TRIM31-WT or Flag-TRIM31-C53/56A plasmid for 24 h followed with SeV infection for indicated times. The data are representative of 3 independent experiments with three biological replicates (means ± S.D. in b, c). *p < 0.01. (two-tailed Student’s t-test).