Structural basis and mechanism of activation of two different families of G proteins by the same GPCR. Academic Article uri icon

Overview

abstract

  • The β1-adrenergic receptor (β1-AR) can activate two families of G proteins. When coupled to Gs, β1-AR increases cardiac output, and coupling to Gi leads to decreased responsiveness in myocardial infarction. By comparative structural analysis of turkey β1-AR complexed with either Gi or Gs, we investigate how a single G-protein-coupled receptor simultaneously signals through two G proteins. We find that, although the critical receptor-interacting C-terminal α5-helices on Gαi and Gαs interact similarly with β1-AR, the overall interacting modes between β1-AR and G proteins vary substantially. Functional studies reveal the importance of the differing interactions and provide evidence that the activation efficacy of G proteins by β1-AR is determined by the entire three-dimensional interaction surface, including intracellular loops 2 and 4 (ICL2 and ICL4).

publication date

  • November 10, 2021

Research

keywords

  • GTP-Binding Protein alpha Subunits, Gi-Go
  • GTP-Binding Protein alpha Subunits, Gs
  • Protein Structure, Tertiary
  • Receptors, Adrenergic, beta-1

Identity

PubMed Central ID

  • PMC8719444

Scopus Document Identifier

  • 85118823775

Digital Object Identifier (DOI)

  • 10.1038/s41594-021-00679-2

PubMed ID

  • 34759376

Additional Document Info

volume

  • 28

issue

  • 11