Structure of the M2 muscarinic receptor-beta-arrestin complex in a lipid nanodisc.Staus, D.P., Hu, H., Robertson, M.J., Kleinhenz, A.L.W., Wingler, L.M., Capel, W.D., Latorraca, N.R., Lefkowitz, R.J., Skiniotis, G.
(2020) Nature 579: 297-302
- PubMed: 31945772
- DOI: 10.1038/s41586-020-1954-0
- Primary Citation of Related Structures:
- PubMed Abstract:
After activation by an agonist, G-protein-coupled receptors (GPCRs) recruit β-arrestin, which desensitizes heterotrimeric G-protein signalling and promotes receptor endocytosis 1 . Additionally, β-arrestin directly regulates many cell signalli ...
After activation by an agonist, G-protein-coupled receptors (GPCRs) recruit β-arrestin, which desensitizes heterotrimeric G-protein signalling and promotes receptor endocytosis 1 . Additionally, β-arrestin directly regulates many cell signalling pathways that can induce cellular responses distinct from that of G proteins 2 . 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 G o protein complex 3 . 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.
Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA. email@example.com.