Fig. (3) STAT5-P transactivates the HIV-1 LTR from subtypes A through G in U937 cells with different potency. A. U937 cells were co-transfected with HIV-1 LTR subtype B responsive firefly luc and vectors expressing either STAT5 or STAT5-P or an empty vector. The results are mean ± SEM of 3 independent experiments. B. U937 cells were co-transfected with vectors expressing the firefly luc under the control of HIV-1 LTR of subtypes A through G and either empty vector or STAT5-P. The luc activity of different HIV-1 LTR subtypes in the presence of vectors expressing either STAT5-P or control empty vector (to which the arbitrary value of 1 was assigned) is shown as fold increase. The results are mean ± SEM of 2 independent experiments.