Structure of the full-length glucagon class B G-protein-coupled receptor

Nature. 2017 Jun 8;546(7657):259-264. doi: 10.1038/nature22363. Epub 2017 May 17.

Abstract

The human glucagon receptor, GCGR, belongs to the class B G-protein-coupled receptor family and plays a key role in glucose homeostasis and the pathophysiology of type 2 diabetes. Here we report the 3.0 Å crystal structure of full-length GCGR containing both the extracellular domain and transmembrane domain in an inactive conformation. The two domains are connected by a 12-residue segment termed the stalk, which adopts a β-strand conformation, instead of forming an α-helix as observed in the previously solved structure of the GCGR transmembrane domain. The first extracellular loop exhibits a β-hairpin conformation and interacts with the stalk to form a compact β-sheet structure. Hydrogen-deuterium exchange, disulfide crosslinking and molecular dynamics studies suggest that the stalk and the first extracellular loop have critical roles in modulating peptide ligand binding and receptor activation. These insights into the full-length GCGR structure deepen our understanding of the signalling mechanisms of class B G-protein-coupled receptors.

Publication types

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

MeSH terms

  • Allosteric Site / drug effects
  • Benzamides / chemistry
  • Benzamides / metabolism
  • Benzamides / pharmacology
  • Cell Membrane / metabolism
  • Cross-Linking Reagents / chemistry
  • Crystallography, X-Ray
  • Deuterium Exchange Measurement
  • Disulfides / chemistry
  • Humans
  • Ligands
  • Models, Molecular
  • Molecular Dynamics Simulation
  • Phenylurea Compounds / chemistry
  • Phenylurea Compounds / metabolism
  • Phenylurea Compounds / pharmacology
  • Protein Domains
  • Protein Stability
  • Receptors, Glucagon / agonists
  • Receptors, Glucagon / chemistry*
  • Receptors, Glucagon / classification*
  • Receptors, Glucagon / metabolism

Substances

  • Benzamides
  • Cross-Linking Reagents
  • Disulfides
  • Ligands
  • NNC0640
  • Phenylurea Compounds
  • Receptors, Glucagon