Valine 571 functions as a regional organizer in programming the glucocorticoid receptor for differential binding of glucocorticoids and mineralocorticoids
1999 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 274, no 26, 18515-18523 p.Article in journal (Refereed) Published
The glucocorticoid receptor (GR) interacts specifically with glucocorticoids, whereas its closest relative, the mineralocorticoid receptor (MR), interacts with both glucocorticoids and mineralocorticoids, such as aldosterone. To investigate the mechanism underlying the glucocorticoid/mineralocorticoid specificity of the GR, we used a yeast model system to screen for GR ligand-binding domain mutants, substituted with MR residues in the segment 565-574, that can be efficiently activated by aldosterone. In all such increased activity mutants, valine 571 was replaced by methionine, even though most mutants also contained substitutions of other residues with their MR counterparts. Further analysis in yeast and COS-7 cells has revealed that the identity of residue 571 determines the behavior of other MR substituted residues in the 565-574 segment. Generally, MR substitutions in this region are only consistent with aldosterone binding if residue 571 is also replaced with methionine (MR conformation). If residue 571 is valine (GR conformation), most other MR substitution mutants drastically reduce interaction with both mineralocorticoid and glucocorticoid hormones. Based on these functional data, we hypothesize that residue 571 functions as a regional organizer involved in discriminating between glucocorticoid and mineralocorticoid hormones. We have used a molecular model of the GR ligand-binding domain in an attempt to interpret our functional data in structural terms.
Place, publisher, year, edition, pages
1999. Vol. 274, no 26, 18515-18523 p.
glucocorticoid receptor, mineralocorticoid, amino acid substitution, animal cell, article, cell strain cos1, conformational transition, hormone receptor interaction, nonhuman, priority journal, protein conformation, receptor affinity, receptor binding, Aldosterone, Amino Acid Sequence, Animals, Binding, Competitive, COS Cells, Glucocorticoids, Ligands, Mineralocorticoids, Models, Molecular, Molecular Sequence Data, Mutagenesis, Site-Directed, Receptors, Glucocorticoid, Receptors, Mineralocorticoid, Structure-Activity Relationship, Trans-Activation (Genetics), Triamcinolone Acetonide, Valine, Animalia
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:sh:diva-22925DOI: 10.1074/jbc.274.26.18515ISI: 000081056700052PubMedID: 10373460ScopusID: 2-s2.0-0033603421OAI: oai:DiVA.org:sh-22925DiVA: diva2:715565