Journal: Tumour Virus Research

Article Title: PRMT5–mediated symmetric dimethylation of SHBs at Arg169 stabilizes SHBs and promotes angiogenesis and tumor growth

doi: 10.1016/j.tvr.2026.200340

Figure Lengend Snippet: PRMT5 stabilizes SHBs protein expression in an Arg169–dependent manner. (A) Huh7 and HepG2 cells were co–transfected with plasmids encoding SHBs–Strep–Flag or SHBs/R169K–Strep–Flag together with increasing amounts of Flag–PRMT5 (0, 1, 3 μg). Whole–cell lysates were immunoblotted for SHBs, Flag, and β–actin; SHBs/β–actin ratios are shown above the blots. (B) Cells expressing SHBs–Strep–Flag or SHBs/R169K–Strep–Flag were transfected with NC or PRMT5 siRNAs (#1, #2). Lysates were immunoblotted for SHBs, PRMT5, and β–actin; SHBs/β–actin ratios are shown. (C–D) Cycloheximide (CHX) chase assays in (C) Huh7 and (D) HepG2 cells. Cells expressing SHBs or SHBs/R169K with vector or Flag–PRMT5 were treated with CHX for the indicated times (0–120 min), followed by WB for SHBs, Flag, and β–actin. Plots show relative SHBs levels normalized to time 0 with fitted linear regression (equations displayed). (E) HepG2 cells were co–transfected with plasmids encoding SHBs–Strep, HA–K48Ub, together with or without Flag–PRMT5, and treated with MG132 (20 μM) for 8 h, the ubiquitination levels of SHBs was evaluated via ubiquitination assay analysis. (F) HepG2 cells were co–transfected with plasmid encoding SHBs–Strep and TRIM21–myc (or control vector) and Flag–PRMT5 (or control vector), the cell lysates were subjected to immunoprecipitation using Strep–Tactin and analyzed by immunoblotting.

Article Snippet: Cells were co–transfected with plasmids encoding Flag–PRMT5 together with SHBs–Strep–Flag or SHBs/R169K–Strep–Flag for 40 h. Cells were then treated with cycloheximide (CHX; 200 μg/mL; MedChemExpress, #HY–12320) to inhibit de novo protein synthesis.

Techniques: Expressing, Transfection, Plasmid Preparation, Ubiquitin Proteomics, Control, Immunoprecipitation, Western Blot