FIG 4.

Tax activates sense transcription but does not affect antisense transcription from chromosomally integrated 5′ LTR/3′ LTR reporter constructs. Graphs on the left of each panel show luciferase activities corresponding to sense (A) or antisense (B) transcription in the presence and absence of Tax from constructs containing the 5′ and 3′ LTRs (LTR/LTR) using four independent clonal cell lines derived from HEK293T cells. Also shown are the mean luciferase activities from eight clonal cell lines in which both LTRs are deleted (−/−). Graphs on the right of each panel show the levels of activation of sense (A) and antisense (B) transcription by Tax in the four clonal cell lines. Luciferase activities are the mean values from three independent experiments. Error bars denote standard deviations.