Identification of an ets motif within the −88/−59 fragment. Nuclear extracts from TGF-β–treated or untreated U937 cells and BAEC were incubated with the [³²P]-labeled −88/−59WT (A and B) or −88/−59Mut fragments (A), in the absence or in the presence of competitor oligonucleotides or specific antibodies as indicated. Excess of unlabeled −88/−59 probe was used as a control for specificity (A and B). The oligonucleotide CD11c-PU.1, containing a consensus binding site for the PU.1 member of the ets family of transcription factors, and fragment BR1, a negative control, were used in competition experiments (B). Specific antibodies to ets-2 or fos/jun were incubated with the nuclear extracts, using a preimmune serum as a negative control (B). Samples were electrophoresed on a 5% polyacrylamide gel and autoradiographed. The presence of specific complexes is indicated by an arrow at the margins. The open arrowheads indicate complexes formed by proteolytic products of ets as previously described.66