(A) GATA1-dependent transcriptional activation of the γ-globin promoter in Med1+/+ MEFs in the presence of 10, 50, 100, and 200 ng of GATA1.
(B) GATA1-dependent and MED1-mediated transcriptional activation. The amounts of the expression vectors added are as follows: 100 ng of GATA1 and 10 or 100 ng of various MED1 fragments.
(C) CCAR1-enhanced activation of GATA1-dependent transcription in Med1+/+ MEFs. The amounts of expression vectors added are as follows: 20 ng of GATA1, 20 or 100 ng of CCAR1, and 100 ng of p300 (*p < .05, **p < .01).
(D) Mammalian two-hybrid assays. Luciferase activities of the reporter with 5× Gal4-binding sites are measured. Gal4-fused MED1 interacts with VP16-fused CCAR1(1–657) and CCAR1(640–1,146).
Values (mean ± SD) of a representative experiment performed in duplicate are shown (A–D). The results were reproducible in three independent experiments.