PMID: 28538729

Authors:

Zhang Y, Sun B, Feng D, Hu H, Chu M, Qu Q, Tarrasch JT, Li S, Sun Kobilka T, Kobilka BK, Skiniotis G

Title:

Cryo-EM structure of the activated GLP-1 receptor in complex with a G protein.

Journal:

Nature. 2017 Jun 8;546(7657):248-253. doi: 10.1038/nature22394. Epub 2017 May 24.

Abstract:

Glucagon-like peptide 1 (GLP-1) is a hormone with essential roles in regulating insulin secretion, carbohydrate metabolism and appetite. GLP-1 effects are mediated through binding to the GLP-1 receptor (GLP-1R), a class B G-protein-coupled receptor (GPCR) that signals primarily through the stimulatory G protein Gs. Class B GPCRs are important therapeutic targets; however, our understanding of their mechanism of action is limited by the lack of structural information on activated and full-length receptors. Here we report the cryo-electron microscopy structure of the peptide-activated GLP-1R-Gs complex at near atomic resolution. The peptide is clasped between the N-terminal domain and the transmembrane core of the receptor, and further stabilized by extracellular loops. Conformational changes in the transmembrane domain result in a sharp kink in the middle of transmembrane helix 6, which pivots its intracellular half outward to accommodate the alpha5-helix of the Ras-like domain of Gs. These results provide a structural framework for understanding class B GPCR activation through hormone binding.