Figure 3
A novel MAZ binding motif in the 34-nt region. (A) The 32P-labeled 34-nt wild type (wt) probes were incubated with HepG2 nuclear extract, and the protein-DNA complexes were separated by 6% nondenaturing acrylamide gel electrophoresis. The DNA-protein complexes were competed by 200-fold molar excess of unlabeled wild type or mutant oligonucleotides. The major complex, minor complex, and free probe are indicated by an arrowhead, a star, and F, respectively. (B) The end-labeled wild type 34-nt probe was incubated with 20 μg cell nuclear extract proteins from HepG2 cells in the absence of competitor (lane 1) and presence of 200-fold molar excess of different unlabeled consensus oligonucleotides representing wild type 34-nt (lane 2), AP2 (lane 3), MAZ (lane 4), HNF-4 (lane 5), Sp1 (lane 6), LF-A1 (lane 7), c-myb (lane 8) and SRE (lane 9) promoter sequences. (C) The effect of 200-fold molar excess of mutant MAZ (mMAZ) and mutant Sp1 (mSp1) oligonucleotides on the mobility shift of the 32P-labeled wild type 34-nt sequence.