Rev and Rex use the Crm1 pathway to enhance expression of RmRE-containing RNAs. Jurkat cells were electroporated with 1 μg of pHMRluc and 1 μg of pGL3 control firefly luciferase plasmid. The EGFP, RemGFP, RevGFP, Rex1GFP or Rex2GFP expression plasmids (10 μg) were added as indicated with or without 20 μg of the plasmid expressing the dominant-negative nucleoporin (pcΔCAN) . All samples were adjusted to the same concentration of DNA with empty vector (pBC12/CMV) prior to transfection. Luciferase activity was determined as described in Figure 2. Renilla luciferase values were normalized for DNA uptake using firefly luciferase activity, and the pHMRluc sample cotransfected with EGFP was assigned a relative value of 1.