Molecular Dynamics Simulations of the Allosteric Modulation of the Adenosine A2A Receptor by a Mini-G Protein

Sci Rep. 2019 Apr 2;9(1):5495. doi: 10.1038/s41598-019-41980-x.

Abstract

Through their coupling to G proteins, G Protein-Coupled Receptors (GPCRs) trigger cellular responses to various signals. Some recent experiments have interestingly demonstrated that the G protein can also act on the receptor by favoring a closed conformation of its orthosteric site, even in the absence of a bound agonist. In this work, we explored such an allosteric modulation by performing extensive molecular dynamics simulations on the adenosine A2 receptor (A2AR) coupled to the Mini-Gs protein. In the presence of the Mini-Gs, we confirmed a restriction of the receptor's agonist binding site that can be explained by a modulation of the intrinsic network of contacts of the receptor. Of interest, we observed similar effects with the C-terminal helix of the Mini-Gs, showing that the observed effect on the binding pocket results from direct local contacts with the bound protein partner that cause a rewiring of the whole receptor's interaction network.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine A2 Receptor Antagonists / chemistry
  • Adenosine A2 Receptor Antagonists / pharmacology
  • Allosteric Regulation
  • Binding Sites
  • Crystallography, X-Ray
  • GTP-Binding Proteins / chemistry*
  • GTP-Binding Proteins / metabolism*
  • Humans
  • Models, Molecular
  • Molecular Dynamics Simulation
  • Protein Binding
  • Protein Structure, Secondary
  • Receptor, Adenosine A2A / chemistry*
  • Receptor, Adenosine A2A / metabolism*

Substances

  • ADORA2A protein, human
  • Adenosine A2 Receptor Antagonists
  • Receptor, Adenosine A2A
  • GTP-Binding Proteins