(A) Transcription factor binding elements within the region of −230 to −50 bp of the human TF promoter. The start site of transcription is indicated by an arrow. Numbering is from the human TF sequence as given in Mackman et al.59 Oligonucleotides spanning the EGR-1/Sp1 sites (designated OL1 to OL6) were used in electrophoretic mobility shift assays. (B) Binding of nuclear proteins to the GC-rich region. Oligonucleotides OL1 to OL6 were radiolabeled and incubated with nuclear extracts from uninduced cells (−) and cells stimulated with VEGF (+) for 1 hour. Protein-DNA complexes I, II, III, and IV are indicated; ns, nonspecific binding. OL4 and OL6 showed identical protein/DNA complexes. Shown is one experiment that is representative of four experiments with similar results.