Beyond the heterodimer model for mineralocorticoid and glucocorticoid receptor interactions in nuclei and at DNA

PLoS One. 2020 Jan 10;15(1):e0227520. doi: 10.1371/journal.pone.0227520. eCollection 2020.

Abstract

Glucocorticoid (GR) and mineralocorticoid receptors (MR) are believed to classically bind DNA as homodimers or MR-GR heterodimers to influence gene regulation in response to pulsatile basal or stress-evoked glucocorticoid secretion. Pulsed corticosterone presentation reveals MR and GR co-occupy DNA only at the peaks of glucocorticoid oscillations, allowing interaction. GR DNA occupancy was pulsatile, while MR DNA occupancy was prolonged through the inter-pulse interval. In mouse mammary 3617 cells MR-GR interacted in the nucleus and at a chromatin-associated DNA binding site. Interactions occurred irrespective of ligand type and receptors formed complexes of higher order than heterodimers. We also detected MR-GR interactions ex-vivo in rat hippocampus. An expanded range of MR-GR interactions predicts structural allostery allowing a variety of transcriptional outcomes and is applicable to the multiple tissue types that co-express both receptors in the same cells whether activated by the same or different hormones.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allosteric Regulation
  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Cell Line
  • Cell Nucleus / metabolism*
  • Chromatin / metabolism
  • Corticosterone / pharmacology
  • DNA / chemistry
  • DNA / metabolism*
  • Dimerization
  • Hippocampus / metabolism
  • Male
  • Protein Interaction Domains and Motifs / drug effects
  • Protein Structure, Quaternary
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Glucocorticoid / chemistry
  • Receptors, Glucocorticoid / genetics
  • Receptors, Glucocorticoid / metabolism*
  • Receptors, Mineralocorticoid / chemistry
  • Receptors, Mineralocorticoid / genetics
  • Receptors, Mineralocorticoid / metabolism*
  • Sequence Alignment
  • Ultradian Rhythm

Substances

  • Chromatin
  • Receptors, Glucocorticoid
  • Receptors, Mineralocorticoid
  • DNA
  • Corticosterone