Transcription factor binding and transactivation capacity of the κB site of β₂m.

(A) EMSA showing binding of complexes to the κB site of β₂m. Using specific Abs, the complex binding to the κB was shown to contain p50 and p65. The presence of c-Rel and RelB was weakly detectable in Raji and MSH B cells. Note the difference in the quantity of complex formation with an equal loading as in Figure3. Arrowheads indicate NF-κB complexes binding the κB site; *, supershifted complex(es). (B) Transient transfection of wild-type β₂m- and κB site–mutated reporter constructs with p50 and p65 expression vectors (1 μg) in Tera-2 cells. The luciferase activity values were normalized with the Renilla luciferase activity values and are expressed as mean ± SD of 4 samples. The induction ratios are indicated above the histogram. RLU indicates relative light units.