FIG. 1.

Cotransfection of luciferase reporter plasmids and Tax in Jurkat cells. (A) The transcription factor recognition sequences of the four luciferase reporter plasmids are highlighted. The plasmid pSRE-Luc contains five copies of the SRE element, which includes the CArG box and TCF binding site, pCArG-Luc contains five copies of the CArG box, pHTLV-Luc contains the HTLV-1 LTR with its three CRE sites, and pNF-κB-Luc contains five copies of the NF-κB DNA binding site. (B) Luciferase assay in which 2 μg of pRS-HTax1C or pBS-RSPA (nonspecific Rous sarcoma virus promoter-containing plasmid) was cotransfected with 2 μg of the indicated reporter plasmids in 2 × 10⁶ Jurkat T cells using Superfect (Qiagen) in a six-well plate. The reporter plasmids are shown on the y axis, and the Tax activation levels normalized for background luciferase expression are presented on the x axis. All experiments were performed at least three times, and the error bars represent the standard deviations.