Figure 4.

MIRN146A (miR-146a) promoter is transactivated by HTLV-1 Tax through a single NF-κB site. (A) Schematic diagram of the 563 bp MIRN146A promoter sequence cloned into pGL3 basic. Proximal (prox.) NF-κB binding site located at 68–77 bp, distal (dist.) at 386–395 bp. (B) Activity of the wildtype promoter was determined in reporter gene assays. Jurkat T cells were cotransfected with the reporter construct and expression plasmids for Tax, its mutant forms M7, M22 and M47, for a constitutively active NF-κB inhibitor (IκBDN) or a control (pcDNA3). Luciferase activity was normalized to protein content. Each combination was tested at least three times. (C), (D) Activity of the promoter with the distal (C) and proximal (D) NF-κB site deleted. See (B) for experimental details. Tax mutant M22 and I BDN expression plasmids were not transfected.