Premium
Oligodeoxynucleotide base recognition by steroid hormone receptors
Author(s) -
Kumar S. Anand,
Beach Thaisa A.,
Dickerman Herbert W.
Publication year - 1983
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240210104
Subject(s) - iodoacetamide , receptor , chemistry , biochemistry , binding site , microbiology and biotechnology , biology , enzyme , cysteine
Oligodeoxynucleotides covalently linked to cellulose were used as probes of the DNA‐binding domains of mouse steroid holoreceptors. With uterine cytosol estrogen receptor (E 2 R) the relative binding order, in prior studies, was oligo(dG) > oligo(dT) ≧ oligo(dC) > > oligo(dA) > oligo(dI). The binding reactions were salt‐sensitive with an optimal KCl concentration of 0.1–0.2 M. There was no enhancement of binding by activation, either temperature‐ or salt‐induced. In the present study, using the oligomer ligands at a lower concentration, oligo(dT) binding was greater than that to oligo(dC). Quantitative differences in oligodeoxynucleotide binding were elicited by a number of inhibitors. These differences are again seen by exposure of E 2 R to chaotropic salts such as SCN − , ClO 4 − and NO 3 − as well as to putative modifiers of receptor amino acids, ie, iodoacetamide, 1,2 cyclohexanedione, and Rose Bengal. These results, and the quantitative differences following heat and purification, led to a designation of two types of subsites within the DNA‐binding domain of uterine E 2 R. These are stable G sites, which interact with oligo(dG); and labile N sites, which bind to oligo(dT), oligo(dC) and oligo(dA). Stimulation of binding to N sites and stabilization of the holoreceptor was effected by histones H2A and H2B. However, the differential response to incubation at 37°C was not altered by addition of H2B. Treatment of uterine E 2 R by limited proteolysis also eliminated the stimulatory response to H2B. The above data, as well as prior studies, indicate that steroid holoreceptors can discriminate between the structural features of deoxynucleotide bases and this recognition process can be modulated by accessory proteins.