Fig. 7. SMAD1 potentiates Notch 1 ICD activation from promoters lacking SMAD1-binding sites. (A) Transfection of Gal4-Notch 1 ICD (100 ng) and SMAD1 (100 ng) in COS-7 cells, in the absence (white bars) or presence (black bars) of exogenous BMP4 (50 ng/ml), measured by activation of the UAS-luc reporter construct. (B) Transfection of Notch 1 ICD (100 ng) and SMAD1 (100 ng) in COS-7 cells, in the absence (white bars) or presence (black bars) of exogenous BMP4 (50 ng/ml), measured by activation of the 12xCSL-luc reporter construct.