Figure 8.

Six predicted RBP-Jκ motifs bind to purified RBP-Jκ protein. A, sequences of EMSA oligos chosen from promoters in Fig. 6. Top (+) and bottom (−) strands are indicated. B and C, competition EMSAs. Increasing amounts of the indicated and unlabeled competitor DNAs were preincubated with GST-RBP-Jκ, before addition of ³²P-labeled Mta proximal (Mta prox) DNA. Mixtures were electrophoresed and visualized by autoradiography. Vertical line in B indicates cropping of irrelevant lanes in center of image. D, quantitation. Shifted complexes from each gel in B were measured by phosphorimaging. Each complex was normalized to the complexes formed by GST-RBP-Jκ and labeled Mta-proximal DNA alone, in each gel, which was set as 100%. Blue text indicates RBP-Jκ motifs from promoters activated by Rta in Fig. 7. prox dist, proximal distal.