Elf1, Tel and Fli1 in splenic NE bind to EBS1, EBS2 and EBS3, respectively. Labeled oligos containing the GATA/EBS1 (A), EBS2 (B) or EBS3 (C) cis-regulatory elements from the murine Fli1 promoter were incubated with NE isolated from BALB/c spleens and unlabeled specific or nonspecific oligos as competitors (Comp) or the antibodies indicated. Elf1, Elf1 binding; Tel, Tel binding; Fli1, Fli1 binding; and ss, supershift are indicated to the right of each gel. Specific competitors: GE (GATA/EBS1), EBS2 and EBS3 are unlabeled wild type oligos. Nonspecific competitors: GmutE contains a wild type EBS1 site and mutated GATA site; GEmut contains a wild type GATA site and a mutated EBS1 site; EBS2mut, contains a mutation disrupting binding to the overlapping EBS2, STATa and Ikaros sites. EMSAs were performed at least three times with multiple NE preparations. EBS3 binding reactions with antibodies to Elf1, GABPα, and GABPβ and unlabeled nonspecific competitor containing a mutated EBS3 site showed no change in binding (data not shown).