Journal: Journal of Virology
Article Title: Cullin 3-mediated ubiquitination restricts enterovirus D68 replication and is counteracted by viral protease 3C
doi: 10.1128/jvi.00354-25
Figure Lengend Snippet: Cullin 3 negatively regulates EV-D68 VP1 protein level. ( A and B ) Virus attachment and entry assays. Stable Cullin 3-knockdown A549 cells were incubated with EV-D68 (Fermon, MOI = 1) at 4 ℃ or 37 ℃ for 2 h, and cells were washed with DMEM to remove unbound viruses. Viral RNA was quantified using qRT-PCR. Data are expressed as the mean ± SD. n.s ., not significant. ( C and D ) EV-D68 5′ UTR activity. Plasmids with the EV-D68 5′ UTR were transfected into HEK293T cells, along with dominant-negative Cullin 3 ( C ) or wild-type Cullin 3 ( D ) plasmids. Control groups were transfected with a control vector. Renilla luciferase activity served as an internal control. The activities of Firefly and Renilla luciferases were measured 48 h post-transfection. The bar graph represents the ratio of Firefly and Renilla luciferase. Data are expressed as the mean ± SD. n.s ., not significant. ( E ) EV-D68 VP1 levels in Cullin 3-knockdown A549 cells. A549 cells pre-transfected with the indicated siRNAs were infected with EV-D68 (Fermon, MOI = 0.05). Cells were harvested 2, 4, 6, 8, and 10 h after infection. VP1 expression levels were detected using an immunoblotting assay. ( F ) VP1–VP3 protein levels in Cullin 3-inhibited HEK293T cells. HEK293T cells were transfected with dominant-negative Cullin 3 or control vectors and VP1–VP3 plasmids. VP1–VP3 levels were measured 48 h after transfection. ( G ) The abundance of VP1–VP3 was quantified using ImageJ software. Data are expressed as the mean ± SD. **** P < 0.0001. *** P < 0.001. ** P < 0.01. ( H ) Immunoblot analysis of VP1 level. HEK293T cells pre-transfected with the VP1 plasmids were treated with MG132 (10 μΜ), MLN4924 (2 μΜ), CQ (50 μΜ), or 3-MA (5 mΜ). The VP1 levels were measured 12 h after treatment.
Article Snippet: The following antibodies were used: anti-Cullin 1 antibody (Abcam, ab75817), anti-Cullin 2 antibody (Abways, CY1025), anti-Cullin 3 antibody (Proteintech, 11107-1-AP), anti-Cullin 4A antibody (Proteintech, 10693-1-AP), anti-Cullin 4B antibody (Proteintech, 12916-1-AP), anti-Cullin 5 antibody (arigo, ARG59155 ), anti-EV-D68-VP1 antibody (GeneTex, GTX132313), anti-HA-tag antibody (Thermo Fisher, 71-5500), anti-Ubiquitin antibody (Proteintech, 10201-2-AP), anti-myc-tag antibody (Sigma, M5546), anti-α-Tubulin antibody (GenScript, A01410), and anti-histone H3 antibody (Abcam, ab176842).
Techniques: Virus, Knockdown, Incubation, Quantitative RT-PCR, Activity Assay, Transfection, Dominant Negative Mutation, Control, Plasmid Preparation, Luciferase, Infection, Expressing, Western Blot, Software