Notch signaling induced by immobilized Delta4 ligand modulates the DNA-binding activity of EBF in 230-238 pre-B cells. (A-B) The resulting autoradiogram of an EMSA experiment where radiolabeled Oct1 protein-binding sites, (A) Cd79a promoter EBF-binding site or (B) λ5 promoter EBF-binding site, were incubated with nuclear extracts from the 230-238 pre-B cell line cultured on either Fc-TRAIL-R4- or Fc-Delta4-coated plates for 48 hours. (C) Display and EMSA results as in panel A, but here the cells were incubated in the presence of the γ-secretase inhibitor DAPT. (D) Diagrams display Q-PCR analysis from the 230-238 cells used in the EMSA. The relative mRNA expression levels of EBF, Cd79a, Pax-5, CD19, B29, and λ5. The data are based on 6 PCR experiments from 2 independent stimulation experiments. Error bars indicate SD.