FIG. 4.

Sequence-specific binding activity of REST to the human IB1 NRSE. (A) EMSA with ³²P-labeled IB1 NRSE using nuclear extracts from HeLa cells. A slow-migrating complex (arrowhead A) was detected, compared to free-probe migration (arrowhead B). This pattern was supershifted by using REST antibodies (arrowhead C). (B) The DNA-binding activity with IB1 NRSE was competed by adding a 100- or 600-fold molar excess of unlabeled wild-type NRSE (Wt) but not by adding unlabeled mutated NRSE (Mut). NS, nonspecific competitor.