Figure 5.

Ascl1a regulates the α1T promoter through the −954 E-box. a, Luciferase reporter vectors with either a minimal β-globin promoter alone (light gray bars) or three copies of the −954 E-box (dark gray bars) or the mutant E-box from probe 4–4 (see Fig. 2b) (black bars) were transfected in combination with ascl1a into HEK293T cells. Ascl1a transactivates the reporter when a functional E-box is present but not when the E-box is mutated. b, Full-length α1T constructs harboring either the wild-type (-1696) or mutant E-box promoters were transfected into HEK293T cells with or without ascl1a. Ascl1a induces reporter expression when the E-box is intact, but not when the E-box is mutated. Error bars indicate SEM for three replicates.