TitleGUANYL NUCLEOTIDES MODULATE BINDING TO STEROID-RECEPTORS IN NEURONAL MEMBRANES
Publication TypeJournal Article
Year of Publication1992
AuthorsOrchinik, M, Murray, TF, Franklin, PH, Moore, FL
JournalProceedings of the National Academy of Sciences of the United States of America
Volume89
Pagination3830-3834
Type of ArticleJournal Article
ISSN0027-8424
Abstract

The recently characterized corticosteroid receptor on amphibian neuronal membranes appears to mediate rapid, stress-induced changes in male reproductive behaviors. Because the transduction mechanisms associated with this receptor are unknown, we performed radioligand binding studies to determine whether this steroid receptor is negatively modulated by guanyl nucleotides. The binding of [H-3]corticosterone to neuronal membranes was inhibited by nonhydrolyzable guanyl nucleotides in both equilibrium saturation binding and titration studies. The addition of guanyl nucleotide plus unlabeled corticosterone induced a rapid phase of [H-3]corticosterone dissociation from membranes that was not induced by addition of unlabeled ligand alone. Furthermore, the equilibrium binding of [H-3]corticosterone and the sensitivity of the receptor to modulation by guanyl nucleotides were both enhanced by Mg2+. These results are consistent with the formation of a ternary complex of steroid, receptor, and guanine nucleotide-binding protein that is subject to regulation by guanyl nucleotides. Therefore, rapid signal transduction through corticosteroid receptors on neuronal membranes appears to be mediated by guanine nucleotide-binding proteins.

URL<Go to ISI>://WOS:A1992HR85300033
DOI10.1073/pnas.89.9.3830