Figure 3.

Forkhead box transcription factors bind to the ACE2 proximal promoter region. (a) An EMSA was conducted with the R4 DNA probe. Nuclear extracts were from untransfected 832/13 cells or 832/13 cells transfected with COUP-TFII or PPARγ expression plasmids. Antibodies against COUP-TFII and PPARγ were included in the binding reactions as indicated. (b) The R6 region has similarity to FOXO1 and FOXA1 motifs as indicated by the BKL TRANSFAC program, whereas the mutation destroys the similarity. (c) An EMSA was done with the R6 probe and nuclear extracts from 832/13 cells that were untransfected or transfected with a FOXO1 expression plasmid (left panel). The right panel shows the effect on the band pattern when an antibody against FOXO1 is included. (d) An EMSA was done with the R6 probe and nuclear extracts from 832/13 cells that were untransfected or transfected with FOXA1, FOXA2, or FOXA3 expression plasmids (left panel). The right panel shows the effects on the band pattern when antibodies against the FOXA transcription factors are included in the binding reactions. (e) An EMSA was conducted with a nuclear extract from 832/13 cells. The probes were the human and mouse R6 regions as well as regions in the distal promoter region with a putative FOXA binding site. An antibody recognizing FOXA1 and FOXA2 was included in the binding reactions as indicated.