Figure 1

BHEXIM1 inhibits BTat transactivation of LTR transcription. (A) Sequence comparison of the bovine and human HEXIM1 proteins. Amino acid differences between the two proteins are shown in shaded boxes. Amino acid deletion (•) is indicated. (B) HeLa cells were transfected with 0.05 μg of the reporter plasmid pHIV LTR-Luc, 0.01 μg of the pCMV-β-gal plasmid, and combined with the indicated amount of HA-HHEXIM1 and with or without HTat (0.025 μg) (left panel). Cf2Th cells were co-transfected with the BIV LTR-Luc plasmid (0.05 μg), the pCMV-β-gal plasmid (0.1 μg), and the indicated amount of the HA-BHEXIM1 expression plasmid with or without BTat (0.025 μg) (right panel). After 48 h, the relative luciferase activities were analyzed. The relative expression of HA-HHEXIM1 or HA-BHEXIM1 in the transfected cells was monitored by WB assay (bottom panel). Error bars represent the SD of the means from three independent experiments.