Download MendeleyStructural equilibrium underlying ligand-dependent activation of beta2-adrenoreceptor.
Imai, S., Yokomizo, T., Kofuku, Y., Shiraishi, Y., Ueda, T., Shimada, I.(2020) Nat Chem Biol 16: 430-439
- PubMed: 31959965 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1038/s41589-019-0457-5
- Primary Citation Related Structures:
6KR8 - PubMed Abstract:
G-protein-coupled receptors (GPCRs) are seven-transmembrane proteins mediating cellular signals in response to extracellular stimuli. Although three-dimensional structures showcase snapshots that can be sampled in the process and nuclear magnetic resonance detects conformational equilibria, the mechanism by which agonist-activated GPCRs interact with various effectors remains elusive. Here, we used paramagnetic nuclear magnetic resonance for leucine amide resonances to visualize the structure of β 2 -adrenoreceptor in the full agonist-bound state, without thermostabilizing mutations abolishing its activity. The structure exhibited a unique orientation of the intracellular half of the transmembrane helix 6, forming a cluster of G-protein-interacting residues. Furthermore, analyses of efficacy-dependent chemical shifts of the residues near the pivotal PIF microswitch identified an equilibrium among three conformations, including one responsible for the varied signal level in each ligand-bound state. Together, these results provide a structural basis for the dynamic activation of GPCRs and shed light on GPCR-mediated signal transduction.
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
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