Figure 4: FBXW7 translocates into the cytoplasm to interact with RIG-I and exert the antiviral function.
From: E3 ligase FBXW7 is critical for RIG-I stabilization during antiviral responses
(a) Confocal microscopy imaging of BMDM infected for indicated hours with VSV and labelled with antibodies to the appropriate protein. Scale bar, 20 μm. (b) Immunoblot analysis of Flag-FBXW7 among nuclear and cytoplasm proteins from overexpressed Flag-FBXW7 HEK293T cells infected with VSV; Lamin A serves as a nuclear control; GAPDH serves as a cytoplasm control. (c) Confocal microscopy imaging of HEK293T cells transfected with Flag-FBXW7 (wt) or Flag-FBXW7 (mutant) plasmid for 24 h, then infected for indicated hours with VSV and labelled with antibodies to the appropriate protein. Scale bar, 20 μm. (d) Quantitative PCR (Q-PCR) analysis of IFN-β and VSV-G mRNA expression in HEK293T cells transfected with Flag-FBXW7 (wt) or Flag-FBXW7 (mutant) plasmid and infected with VSV for indicated hours. (e) Confocal microscopy imaging of HEK293T cells that transfected with Flag-FBXW7 (wt) or Flag-FBXW7 (mutant) together with Myc-RIG-I plasmids followed by VSV infection for 6 h. Scale bar, 20 μm. (f) Immunoblot analysis of the K48 ubiquitination of RIG-I in FBXW7f/f and Lysm+FBXW7f/f peritoneal macrophages infected with VSV. Data are mean±s.e.m. and are representative of three independent experiments. Student’s t-test was used for statistical calculation. **P<0.01 and ***P<0.001.
