Unraveling the Allosteric Cross-Talk Between Coactivator Peptide and Ligand Binding Site in Glucocorticoid Receptor

Glucocorticoid receptor (GR) is a nuclear receptor that controls critical biological processes by regulating the transcription of specific genes. There is a known allosteric cross-talk between the ligand and coregulator binding sites within the GR ligand binding domain that is crucial for the control of the functional response. However, the molecular mechanisms underlying such an allosteric control remain elusive. Here, molecular dynamics (MD) simulations, bioinformatic analysis and biophysical measurements are integrated to capture the structural and dynamic features of the allosteric cross-talk within GR. We identified a network of evolutionarily conserved residues that enables the allosteric signal transduction, in agreement with experimental data. MD simulations clarify how such network is dynamically interconnected and offer a mechanistic explanation of how the different peptides affect the intensity of the allosteric signal. This study provides useful insights to elucidate the GR allosteric regulation, ultimately, posing the foundation for designing novel drugs.