Sequences flanking the core-binding site modulate glucocorticoid receptor structure and activity

Nat Commun. 2016 Sep 1;7:12621. doi: 10.1038/ncomms12621.

Abstract

The glucocorticoid receptor (GR) binds as a homodimer to genomic response elements, which have particular sequence and shape characteristics. Here we show that the nucleotides directly flanking the core-binding site, differ depending on the strength of GR-dependent activation of nearby genes. Our study indicates that these flanking nucleotides change the three-dimensional structure of the DNA-binding site, the DNA-binding domain of GR and the quaternary structure of the dimeric complex. Functional studies in a defined genomic context show that sequence-induced changes in GR activity cannot be explained by differences in GR occupancy. Rather, mutating the dimerization interface mitigates DNA-induced changes in both activity and structure, arguing for a role of DNA-induced structural changes in modulating GR activity. Together, our study shows that DNA sequence identity of genomic binding sites modulates GR activity downstream of binding, which may play a role in achieving regulatory specificity towards individual target genes.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Base Sequence
  • Binding Sites / genetics
  • Cell Line, Tumor
  • DNA / genetics*
  • Humans
  • Protein Domains / genetics
  • Protein Structure, Quaternary / genetics
  • Receptors, Glucocorticoid* / genetics
  • Receptors, Glucocorticoid* / metabolism
  • Receptors, Glucocorticoid* / ultrastructure
  • Transcription Factors / genetics

Substances

  • Receptors, Glucocorticoid
  • Transcription Factors
  • DNA