Transcriptional Regulation of Mouse PXR Gene: An Interplay of Transregulatory Factors
Figure 7
Sequence specific binding of Ets and LEF transcription factors to −297/−163 mouse proximal PXR promoter. A
) A 134 bp (−297 to −163) PCR amplified fragment was radiolabeled and incubated with Hepa 1–6 cell lysate and competition assays were performed with 50- to 100-fold molar excess of unlabelled self-nucleotides (lanes 3 and 4), unlabelled oligonucleotide −283/−252 (lanes 5 and 6) and unlabelled oligonucleotide −243/−219 (lanes 7 and 8). B) Supershift EMSA, designed to identify specific protein interactions with −297/−163 radiolabeled probe. The reaction mixtures were incubated with pre-immune (lane 3), Sp-1(lane 4), β-catenin (lane 5), PU.1 (lane 6) and Ets-1(lane 7) antibodies before DNA-protein complexes were subjected to electrophoresis on 5% native PAGE (15 μg of protein/lane). Specific bands are shown with the filled arrows and super-shifted bands are shown with an open arrow.