FIG. 2.
HTLV-2 p28II inhibits Tax-2 and Rex-2 expression only when they are expressed from a full-length proviral clone. (A) A total of 0.4 μg of wtHTLV-2 plasmid or 0.1 μg of Tax-2 cDNA plasmid was transfected into 293T cells along with the LTR-luciferase reporter in the absence or presence of a 2× or 4× molar ratio of p28II expression plasmid. After 48 h of culture, cells were lysed, and luciferase activity was measured. Experiments were done in triplicate, and CMV-βgal was used to adjust for transfection efficiency. Negative control (NC), cells that are transfected with an empty vector. (B) The same lysates shown in panel A were separated on 4 to 12% SDS-PAGE gels and transferred onto nitrocellulose membranes, followed by Western blotting using antibodies specific for Tax-2, Rex-2, p28II, or actin (LC). Rex-2 migrates as two bands, p24 (hypophosphorylated) and p26 (phosphorylated).