Figure 3.

Mad3 binds to the Id2 promoter. (A) Cell extracts from CD74−/− or control B cells were incubated in with or without an anti-Mad3 Ab (Mad3) or an isotype control antibody (Con) and analyzed by EMSA with the oligonucleotide CAAATG. (B) Cell extracts from CD74−/− or control B cells were incubated with or without anti-Mad4 (Mad4), anti-Max (Max), or isotype control (Con) Abs and analyzed by EMSA with the CAAATG oligonucleotide probe. (C and D) ChIP analysis of Mad3 (C) or Mad 4 (D) binding to the Id2 promoter. Chromatin prepared from CD74−/− (C) or control (D) B cells was immunoprecipitated with control or anti-Mad3 (C) or anti-Mad4 (D) antibodies. Presence of the promoter sequence was then quantified by quantitative real-time PCR. Results presented are representative of at least three separate experiments.