Fig. 3.

Dlx3 binds to 2 cis-elements within the murine MMP-9 promoter fragment. A: bioinformatic investigation of the MMP-9 gene promoter identified 2 near-consensus Dlx3 binding sites based upon homology to a consensus Dlx3 site. Positions of these sites (designated as probes) were at −1,498 and −825 relative to the start site of transcription. B: with the use of EMSA, both binding sites were found to bind recombinant (r)Dlx3 with differing relative affinity. Dlx3 complexes as well as free probe are identified by arrows at left. C: with the use of JEG3 nuclear extracts as a source of Dlx3 binding activity, DNA affinity chromatography followed by Western blot studies revealed Dlx3 bound the −1,498 and −825 sites consistent with EMSA. Competition studies using the −1,498 and −825 binding sites at 20-fold molar excess of unbiotinylated oligonucleotides were used to demonstrate specificity of binding. All studies were replicated on at least 3 separate occasions with equivalent results.