FIGURE 2.

UBR5 regulates HBZ protein stability. (A) HEK293T cells were infected with three different lentiviral vectors expressing shRNA directed against UBR5, or control shRNAs. After a brief puromycin selection, the cells were then transfected with HBZ or APH-2 expression plasmid. After 48 h, immunoblot analysis was performed to detect HBZ, APH-2, and UBR5 expression levels. β-actin was used as a loading control while PRMT5 was used as an internal control. (B) HEK293T and (C) Jurkat-HBZ cells were infected with either a lentiviral vector directed against UBR5 or a control shRNA. After a brief puromycin selection, the HEK293T cells were transfected with HBZ expression plasmid and used for cycloheximide pulse chase experiments after 48 h. Cells were treated with 100 μg/ml cycloheximide for the indicated times. Immunoblot analysis was performed to detect HBZ, UBR5, and β-actin (loading control) expression levels.