Figure 6.

Co-immunoprecipitation POU1F1 with three cofactors. Interactions are compared among the WT POU1F1 and a series of derived alanine substitutions surrounding proline 76 site. HEK293T cells were co-transfected with plasmids pcDNA4-POU1F1-HA expressing POU1F1_WT or L74A, T75A, P76L, P76A, C77A, L78A and pcDNA3-PITX1 or pcDNA3-LHX3a-Flag or pcDNA3-ELK1-Flag. Co-immunoprecipitations were performed with an anti-PITX1 antibody (A) or Flag antibodies for LHX3a (B) and ELK1 (C) on nuclear extracts samples. Western blots were generated using an anti-HA antibody. Quantification of the complex formed, represented by histograms (right side), was evaluated as the ratio of protein immunoprecipitated to protein expressed (input).