We investigated the interaction between the nuclear factors from HeLa and rnt pituitary GC cells and DNA fragment containing sequences -335∼-240 upstream of bovine growth hormone (bGH) gene, which down-regulates its expression. The putative NF-I bin...
We investigated the interaction between the nuclear factors from HeLa and rnt pituitary GC cells and DNA fragment containing sequences -335∼-240 upstream of bovine growth hormone (bGH) gene, which down-regulates its expression. The putative NF-I binding site on this negative regulatory site (NRS) was shown to bind some nuclear factors by gel mobility shift and footprinting analysis. It was observed that many factors bind to NRS specifically in both HeLa and GC cells. The band patterns in gel mobility shift assay were similar in two cells with only minor differences. To localize the binding site on NRS, we performed footprinting analysis using DNase I and hydroxyl radical cleavage. Not only the protected footprints in -293∼-286, -268∼-258, and -251∼-243 region, but the hypersensitive sites at -295, -281, -276, -275, -263, -262 and -252 were observed in common in both cell lines. However, the protected regions in -319∼-302 and -285∼-268 were observed only in HeLa cell, which may imply the differences in cell specificity of NRS activity.