Fig. 1. The Slug transcription factor binds to the E-pal element of E-cadherin promoter through the E-boxes. (A) Recombinant GST-Slug protein (1 µg) was incubated with the ³²P-labeled E-pal probe in the absence or presence of 500-fold molar excess of wild-type or mutant cold oligonucleotides or in the presence of 5 µg of anti-Slug monoclonal antibody or control mouse IgG. The retarded complexes are indicated by arrows and the supershifted complex by an arrowhead. (B). Recombinant GST, GST-Snail, GST-Slug and GST-E47 proteins were incubated at the indicated combinations with the ³²P-labeled wild-type E-pal probe. The different retarded complexes detected are indicated by arrows. The complete sequence of the E-pal probe is indicated at the bottom of the figure with the two E-boxes showed in black letters. Asterisks indicate the position of the mutated nucleotides in the mEpal oligonucleotide.