ASSESSMENT OF SPECIFICITY OF ESTROGEN RECEPTOR-DNA INTERACTION BY A COMPETITIVE ASSAY

ALTHOUGH hormonal regulation of gene expression and the nature of specific interactions between steroid hormone receptor and genome have attracted growing interest1-5, very little is known about the molecular nature of receptor-DNA interaction4-6. As a first step in unravelling the specificity and the dynamics of the interaction between uterine oestrogen receptor and DNA7-11, we have selected a well defined model system: a synthetic DNA and DNA-cellulose competition assay. We have found that the AT-rich segment of the double stranded DNA in its intact conformation is required for optimum receptor binding. We have examined oestrogen receptor binding to synthetic DNA with well defined sequences, and determined whether the receptor favours double-stranded or single-stranded regions of the DNA (unwinding protein generally binds preferentially to single-stranded DNA 12). Finally, we have studied the effect of an intercalating drug, actinomycin D, on the receptor binding. © 1978 Nature Publishing Group.