DNA-BINDING PROPERTIES OF THE OVEREXPRESSED RECOMBINANT ESTROGEN-RECEPTOR-ALPHA

Estrogen receptor a was overexpressed in COS-7 cells by transformation of an expression vector with the full length open reading frame of th e receptor a. The nuclear estradiol-receptor complex and the soluble r eceptor from the COS-7 cells were cross-linked with an estrogen respon se element (ERE), which was substituted with 5-bromo-2'-deoxyuridine ( BrdUVRE), as the receptor dimers by UV irradiation. In gel retardation analysis, the specific bindings of both nuclear and soluble receptors to ERE were decreased with increasing of KCI concentration compared w ith 0.1 M KCl. The ionic interactions of both receptors with ERE are t hought to be similar.