Figure 5.

Overexpressing A20 abolishes HMBA's enhancing effect on prostratin-induced NF-κB activation. (a) A20 overexpression attenuates HMBA-enhanced IκBα degradation which was induced by prostratin. HeLa cells infected with lentivirus expressing A20 were treated as indicated. The levels of IκBα in cell lysates were analyzed by Western Blot (WB). (b) A20 overexpression abolishes HMBA and prostratin- (H+P-) activated nuclear translocation of RelA. HeLa cells cotransfected with HA-RelA plus empty vector or Flag-A20 constructs were treated as indicated, followed by immunofluorescence analysis with anti-HA antibody. (c) A20 overexpression inhibits H+P-activated HIV-1 expression. HIV-LTR-Luc cells transfected with HA-A20 construct or empty vector were treated as indicated. The cell lysates were prepared for luciferase assay as in Figure 1(d). (d) A20 overexpression attenuates H+P-activated HIV-1 transcriptional initiation and elongation. HIV-LTR-Luc cells transfected with HA-A20 construct or empty vector were treated as indicated. The RNA was isolated for qRT-PCR analysis as in Figure 1(e).