Figure 2.

Interaction of ETS proteins with target promoters. (A) EMSA of ETS1 and FLI1 with Egr1 SREI and SREII. The ETS1 and FLI1 proteins were expressed in insect cells, and the cell extracts were prepared as described (19). Cell extracts (1 μg) contained ETS1 (lanes 1–8) and FLI1 (lanes 9–16) and SREI oligonucleotides (lanes 1–4 and 9–12) and SREII oligonucleotides (lanes 5–8 and 13–16) (19). The binding was performed in the presence of excess oligonucleotides (lanes 2, 4, 6, 8, 10, 12, 14, and 16) and specific mAb (lanes 3, 7, 11, and 15). Arrows indicate protein–DNA complexes in the absence (I) or presence (II) of mAb. (B) EMSA of FLI1 with preproapolipoprotein C II serglycin promoters. ³²P-labeled EBS containing oligonucleotides were incubated with FLI1 protein in the presence (lanes 2 and 4) or absence (lanes 1 and 3) of competitor. Arrow indicates the binding of FLI1 to preproapolipoprotein C II and serglycin promoter EBSs.