Download MendeleyStructural basis of PTH1R-beta-arrestin core engagement reveals design principles for G-protein-biased therapeutics.
Zhao, L.H., He, Q., Yuan, Q., Zhang, M., Zhao, G.G., Sun, J., Hu, W., Shan, H., Xu, H.E.(2026) Nat Struct Mol Biol 33: 868-881
- PubMed: 42115346 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1038/s41594-026-01806-7
- Primary Citation Related Structures:
8YFO, 8YG4, 9LXP, 9LXR, 9LY2, 9LY3 - PubMed Abstract:
G-protein-coupled receptors (GPCRs) transmit cellular signals through both G protein and arrestin pathways and biased signaling offers potential therapeutic advantages through selective activation. Although GPCR-G protein complexes are well characterized, structural understanding of class B GPCR-arrestin interactions remains limited. Here we show the cryo-electron microscopy structure of parathyroid hormone receptor 1 in core engagement with β-arrestin 1, revealing the molecular basis of arrestin coupling. The structure shows a rearrangement in which inward movement of extracellular transmembrane helix 5 (TM5) and extracellular loop 3 (ECL3) drives outward displacement of cytoplasmic TM5, forming a configuration required for arrestin binding. Guided by comparison with the G s -coupled state, we designed peptide analogs that prevent these TM5/ECL3 conformational changes, producing G-protein-biased agonists that preserve agonist efficacy while reducing arrestin recruitment. In an ovariectomized mouse model, a lead compound shows comparable therapeutic efficacy, providing a framework for structure-guided design of biased therapeutics targeting class B GPCRs.
- Research Center for Medicinal Structural Biology, National Research Center for Translational Medicine at Shanghai, State Key Laboratory of Medical Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. zlh13131@rjh.com.cn.
Organizational Affiliation:
