Figure 5.

TF binding to the HLA enhanceosome. A. EMSA of HLA probes from the upstream CREB site (UP-CREB), ETS/RFX site, and CREB site. Nuclear lysate from JAR, BeWo, or HEK293 cells was used, as indicated below each panel. Probe regions are indicated at the top of each panel, with brackets encompassing the individual HLA gene probes used. Arrows indicate CREB-binding protein complex (CREB), ELF1 complex (ELF1), HLA-C-specific (C-sp), and HLA-A-specific (A-sp) complexes. B. Competition of HLA-C ETS/RFX complexes formed in JAR cell nuclear lysate with unlabeled TF consensus oligonucleotides. The left panel shows results with decreasing amount of a consensus ETS oligonucleotide from 50-fold excess (50×) to equimolar (1×). Arrows indicate inhibited complexes. The right panel shows competition with a 50-fold excess of C/EBP, ETS, and STAT consensus oligonucleotides. C. Supershift analysis with anti-ETS family antibodies. JAR nuclear lysate was pre-incubated with the indicated antibodies prior to adding the labeled HLA-C ETS/RFX probe. The positions of the ELF1 complex and the supershifted antibody bands are indicated by arrows.