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-Structure paper
Title | Conserved class B GPCR activation by a biased intracellular agonist. |
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Journal, issue, pages | Nature, Vol. 621, Issue 7979, Page 635-641, Year 2023 |
Publish date | Jul 31, 2023 |
Authors | Li-Hua Zhao / Qian He / Qingning Yuan / Yimin Gu / Xinheng He / Hong Shan / Junrui Li / Kai Wang / Yang Li / Wen Hu / Kai Wu / Jianhua Shen / H Eric Xu / |
PubMed Abstract | Class B G-protein-coupled receptors (GPCRs), including glucagon-like peptide 1 receptor (GLP1R) and parathyroid hormone 1 receptor (PTH1R), are important drug targets. Injectable peptide drugs ...Class B G-protein-coupled receptors (GPCRs), including glucagon-like peptide 1 receptor (GLP1R) and parathyroid hormone 1 receptor (PTH1R), are important drug targets. Injectable peptide drugs targeting these receptors have been developed, but orally available small-molecule drugs remain under development. Here we report the high-resolution structure of human PTH1R in complex with the stimulatory G protein (G) and a small-molecule agonist, PCO371, which reveals an unexpected binding mode of PCO371 at the cytoplasmic interface of PTH1R with G. The PCO371-binding site is totally different from all binding sites previously reported for small molecules or peptide ligands in GPCRs. The residues that make up the PCO371-binding pocket are conserved in class B GPCRs, and a single alteration in PTH2R and two residue alterations in GLP1R convert these receptors to respond to PCO371. Functional assays reveal that PCO371 is a G-protein-biased agonist that is defective in promoting PTH1R-mediated arrestin signalling. Together, these results uncover a distinct binding site for designing small-molecule agonists for PTH1R and possibly other members of the class B GPCRs and define a receptor conformation that is specific only for G-protein activation but not arrestin signalling. These insights should facilitate the design of distinct types of class B GPCR small-molecule agonist for various therapeutic indications. |
External links | Nature / PubMed:37524305 |
Methods | EM (single particle) |
Resolution | 2.57 Å |
Structure data | EMDB-36593, PDB-8jr9: |
Chemicals | ChemComp-KHF: |
Source |
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Keywords | MEMBRANE PROTEIN / Class B / GPCR |