The dioxin receptor: characterization of its DNA-binding properties.
The binding of the rat hepatic dioxin and glucocorticoid receptors to the polyanionic matrices heparin-Sepharose and DNA-cellulose in vitro and to cell nuclei in vivo was studied under various conditions. In a non-liganded and non-activated state both receptors eluted from heparin-Sepharose at a low ionic strength and were not retained on DNA-cellulose. Following ligandation and activation in vitro both receptors showed an increased affinity for heparin-Sepharose and were retained on DNA-cellulose. In analogy to these in vitro data, it was found that a high salt concentration (0.4 M KCl) was required to extract in vivo liganded dioxin receptor from purified nuclear preparations in contrast to that previously reported for non-liganded nuclear receptors. Limited proteolysis of both dioxin and glucocorticoid receptors resulted in molecular species of similar binding properties with regard to DNA-cellulose and heparin-Sepharose. We conclude that, in addition to the dioxin and glucocorticoid receptors showing considerable similarities in their physicochemical properties, they may also share a similar structural organization with regard to functional domains.
Mason
G G
GG
Department of Medical Nutrition, Karolinska Institutet, Huddinge University Hospital, Sweden.
Wilhelmsson
A
A
Cuthill
S
S
Gillner
M
M
Poellinger
L
L
Gustafsson
J A
JA
D000818:Animals; D004247:DNA / Q000378:metabolism*; D004147:Dioxins / Q000378:metabolism*; D008024:Ligands; D008099:Liver / Q000378:metabolism*; D008970:Molecular Weight; D011485:Protein Binding; D051381:Rats; D011955:Receptors, Drug / Q000302:isolation & purification / Q000378:metabolism*; D011965:Receptors, Glucocorticoid / Q000302:isolation & purification / Q000378:metabolism*
D004147:Dioxins; D008024:Ligands; D011955:Receptors, Drug; D011965:Receptors, Glucocorticoid; D004247:DNA