Figure 4.

Site-directed mutation of CREB, NF-Y, and ETS/RFX sites. Sequence elements were exchanged between the HLA-A and HLA-C genes. The CREB and NF-Y sites of HLA-C were inserted into the HLA-A gene either alone (A+CREB; A+NF-Y) or in combination (A+CREB/NF-Y). The RFX-binding site was mutated to the HLA-C sequence (A-RFX). Conversely, HLA-A sequence was used to disrupt the CREB (C-CREB) or NF-Y (C-NF-Y) sites, add the RFX (C+RFX) site, or add the RFX site and mutate the ETS site (C+RFX-ETS) of the HLA-C core promoter. Constructs were transfected into HEK293T (A), BeWo (B), or JAR (C) and promoter activity was normalized to HLA-C core promoter activity. Results are the average of four independent experiments. Error bars represent +/− SEM.