Structural Basis for Allosteric Regulation of GPCRs by Sodium Ions

Abstract

GPCR Close-Up Structures of G protein–coupled receptors (GPCRs) determined in the past few years, have provided insight into the function of this important family of membrane proteins. Liu et al. (p. 232 ) used a protein-engineering strategy to produce a stabilized version of the human A 2A adenosine receptor (A 2A AR). The high-resolution structure reveals the position of about 60 internal waters, which suggests an almost continuous channel in the GPCR and can explain the allosteric effects of Na + on ligand binding and how cholesterol may contribute to GPCR stabilization.