FIG. 5.
Loss of hERα DNA binding is due to inhibition of dimerization. (A) Gel shifts were performed with extracts prepared from COS-1 cells transfected with HEG0 alone (lane 2) or together with wild-type HEG19 or serine 236 mutants (lanes 3 to 6) and HEG19 alone (lane 7) or together with serine 236 mutants of HEG0 (lanes 8 to 10). (B) HEG0, HEG19, HEG0236E, and HEG19236E were synthesised in vitro either separately or together in the presence of [35S]methionine. The in vitro translation products were divided in two and immunoprecipitated with the B10 monoclonal antibody (lanes 1 to 7). Immunoprecipitation with the F3 (lanes 8 to 14) monoclonal antibody was used to show that HEG0, HEG19, and the 236E mutants are present in the appropriate in vitro translations. (C) HEG0, HEG0236E, and hERβ1 were synthesized in vitro either separately or together in the presence of [35S]methionine. The in vitro translation products were divided in two and immunoprecipitated with B10 (lanes 1 to 5) or M2 (lanes 6 to 10) monoclonal antibodies.