Integrative structure determination of the GLP-1 receptor-Gs complex

Summary

The GLP-1 receptor (GLP-1R) is a prototypical class B G protein-coupled receptor (GPCR) that is predominantly coupled to the stimulatory Gs protein, which increases intracellular cAMP levels. Despite the determination of multiple high-resolution structures of the active-state GLP-1R-Gs complex, deciphering its structure and function mechanisms through conventional methods has been challenging. In this study, by combining cross-linking mass spectrometry (CLMS) with integrative structure modeling, we map the conformational ensemble of an activated GLP-1R-Gs complex at near atomic resolution. The integrative structures describe heterogeneous conformations for a high number of potential alternative active states of the GLP-1 receptor-Gs complex. These structures show marked differences from the previously determined cryo-EM structure, especially at the receptor-Gs interface and in the interior of the Gs heterotrimer. Alanine-scanning mutagenesis coupled with pharmacological assays validates the functional significance of 24 interface residue contacts only observed in the integrative structures, yet absent in the cryo-EM structure.

These scripts demonstrate the use of IMP in the modeling of the GLP-1R-Gs complex using multi-crosslinking datasets. The scripts work with the IMP (Release 2.12.0).

List of files and directories:

• data contains the relevant information: experimental data, statistical analyses, and prior information.
• modeling_scripts contains the modeling script for determining structures to reproduce the ensemble of solutions.
• results contains the analysis scripts and the relevent results discussed in the published paper.

Integrative modeling approach summary for this project

Information

Author(s): Liping Sun, Chenxi Wang

License: CC BY-SA 4.0 This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.

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