FIG. 2.

Cloning of the proximal Ebf1β promoter and comparison with the distal Ebf1α promoter. (A) Schematic overview of the Ebf1α and Ebf1β promoter luciferase reporter constructs. (B) Comparison of the promoter activities of the two Ebf1 promoters in transient-transfection assays of B- and non-B-cell lines. Three micrograms of α(−1.1)-luc, β(−1.7)-luc, or pGl3-luc was transfected together with 1 μg cytomegalovirus β-galactosidase reporter into PD36 pre-B cells, Raji mature B cells, 3T3L1 preadipocytes, EL4 pre-T cells, or NIH 3T3 fibroblasts. The activation (n-fold) compared to that of pGl3-luc is depicted. (C) Transient transfection of Ebf1β promoter constructs into Raji B cells. The empty-vector control pGl3-luc was compared to the Ebf1 promoter constructs α(−1.1)-luc, α(flip)-luc, β(−1.7)-luc, β(flip)-luc, β(−0.5)-luc, α-β-luc, and α(flip)-β-luc. Three micrograms of each luciferase construct was transfected together with 1 μg cytomegalovirus β-galactosidase reporter into Raji B cells. The levels of luciferase activity, normalized to the activity of the cotransfected β-galactosidase reporter, are expressed as activation (n-fold) relative to the luciferase levels of cells transfected with pGl3-luc. All transfections were performed at least three times, and results from representative experiments with standard deviations are shown.