FIG. 7.

Finb/RREB-1 interacts with BETA2/NeuroD. (A) Heparin-agarose-purified binding activity from HIT cell nuclear extract was examined in a gel shift assay in the absence (lane 1) or presence of anti-E47 (lane 2), anti-Sp1 (lane 3), or anti-BETA2 (lane 4) antibody. (B) C33A cells were cotransfected with an equal amount (1 μg) of Finb expression plasmid or pcDNA (empty vector) in the absence or presence of BETA2 expression plasmid (0.05 μg) and a reporter plasmid (0.25 μg) containing the wild-type secretin promoter (white bars), the mutant promoter lacking the functional upstream element (gray bars), or the E-box element (black bars). Results are shown as the means ± SEM for at least three separate experiments. *, significantly different (P < 0.001) from the respective control (pcDNA); **, significantly different (P < 0.001) from BETA2 alone.