Luciferase reporter assay.

<p>(A) Schematic representation of the region of the human eIF6 promoter containing two putative RBP-jk-binding sites (sites A-B). Different tracts of the promoter were cloned upstream of the luciferase gene in the pGL3 Basic luciferase plasmid obtaining the constructs indicated as FL, FR1, FR2 and FR3. (B) Luciferase assay. NIH-3T3 cells were cotransfected with <i>Renilla</i> luciferase plasmid and one of the reporter plasmids shown in A in the presence (black columns) or the absence (grey columns) of a plasmid expressing human Notch-1 (N1). (C) NIH-3T3 cells co-transfected with the FL plasmid and the N1 plasmid were further transfected with increasing amounts (0,25-0,5-1 µg) of a plasmid expressing a dominant-negative form of RBP-jk (RBP-jk DN).