Binding of USF1 and USF2 to the TME in HEL cells. (A) Detection of USF1 and USF2 among the TME binding proteins. Western blotting was performed with fractions from a DNA affinity column. Fraction numbers of affinity column elute are indicated above. *Faint USF1 band. TME binding activity of each fraction was measured by EMSA. (B-C) Detection of USF1 and USF2 in the TME binding complex in HEL cells by the supershift assay. A supershift assay was performed with nuclear extracts of HEL cells and factor-specific antibodies. Arrow indicates supershifted band. The TME probe (B) or TMEmut probe (C) that includes the mutations in the E-box motifs was used. (–) indicates no antibody.