Structure of the M2 muscarinic receptor-β-arrestin complex in a lipid nanodisc.

Published

Journal Article

After activation by an agonist, G-protein-coupled receptors (GPCRs) recruit β-arrestin, which desensitizes heterotrimeric G-protein signalling and promotes receptor endocytosis1. Additionally, β-arrestin directly regulates many cell signalling pathways that can induce cellular responses distinct from that of G proteins2. In contrast to G proteins, for which there are many high-resolution structures in complex with GPCRs, the molecular mechanisms underlying the interaction of β-arrestin with GPCRs are much less understood. Here we present a cryo-electron microscopy structure of β-arrestin 1 (βarr1) in complex with M2 muscarinic receptor (M2R) reconstituted in lipid nanodiscs. The M2R-βarr1 complex displays a multimodal network of flexible interactions, including binding of the N domain of βarr1 to phosphorylated receptor residues and insertion of the finger loop of βarr1 into the M2R seven-transmembrane bundle, which adopts a conformation similar to that in the M2R-heterotrimeric Go protein complex3. Moreover, the cryo-electron microscopy map reveals that the C-edge of βarr1 engages the lipid bilayer. Through atomistic simulations and biophysical, biochemical and cellular assays, we show that the C-edge is critical for stable complex formation, βarr1 recruitment, receptor internalization, and desensitization of G-protein activation. Taken together, these data suggest that the cooperative interactions of β-arrestin with both the receptor and the phospholipid bilayer contribute to its functional versatility.

Full Text

Duke Authors

Cited Authors

  • Staus, DP; Hu, H; Robertson, MJ; Kleinhenz, ALW; Wingler, LM; Capel, WD; Latorraca, NR; Lefkowitz, RJ; Skiniotis, G

Published Date

  • March 2020

Published In

Volume / Issue

  • 579 / 7798

Start / End Page

  • 297 - 302

PubMed ID

  • 31945772

Pubmed Central ID

  • 31945772

Electronic International Standard Serial Number (EISSN)

  • 1476-4687

Digital Object Identifier (DOI)

  • 10.1038/s41586-020-1954-0

Language

  • eng

Conference Location

  • England