Transcriptional Regulation of the HMGA1 Gene by Octamer-Binding Proteins Oct-1 and Oct-2
Figure 2
Nuclear protein-DNA interaction within P3 and P5 fragments of the HMGA1 promoter.
(A) Nuclear extracts (NE) from IM-9 cells were incubated with P3 (left) or P5 (right) probe (0.2 ng each), in the presence of 0.2 µg of poly(dI-dC), which was used as the competitor DNA for nonspecific DNA-binding proteins in the nuclear extracts. DNA protein complexes were resolved on a 6% non-denaturing polyacrylamide gel. (B) Labeled P3 and P5, and a mutant version of either P3 (P3m) or P5 (P5m) probe were used in EMSAs with 4 µg of NE from IM-9 cells under the same conditions as in (A). Sequence specificity of HMGA1 DNA binding proteins was determined by using 10–30 fold molar excess of unlabeled fragment P3 (left) or P5 (right) as competitors. Free (DNA) and bound (DNA-P) probe is indicated. A representative of three separate assays is shown for each condition.