Fig. 4.

Endogenous RelB facilitates Tat-induced, TAR-independent HIV-1 LTR transactivation. a Control and RELB^−/− HeLa cells (0.1 × 10⁶) were transfected by indicated plasmids (pHA-Tat: 100 ng, pHA-RelB: 100 ng) and pHIV-1-LTR-luc luciferase reporter plasmids (100 ng). b Schematic representation of the CycT1-Tat-TAR ternary complex and TAR mutation. c Control and RELB^−/− HeLa cells (0.1 × 10⁶) were transfected with the indicated plasmids (pHA-Tat: 100 ng, pHA-RelB: 100 ng) and pHIV-1-LTR-luc luciferase reporter plasmids (100 ng). To normalize transfection efficiency, phRluc-TK (1 ng) was co-transfected. The Rel. Luc. Act in the figure was calculated relative to normalized luciferase activity of pHIV-1-LTR-luc with Tat (with or without RelB) and vectors co-transfected cells. The relative expression of RelB in the transfected cells was monitored by western blotting