Sodium is a negative allosteric regulator of the ghrelin receptor.
Cell Rep
; 42(4): 112320, 2023 04 25.
Article
em En
| MEDLINE
| ID: mdl-37027306
ABSTRACT
The functional properties of G protein-coupled receptors (GPCRs) are intimately associated with the different components in their cellular environment. Among them, sodium ions have been proposed to play a substantial role as endogenous allosteric modulators of GPCR-mediated signaling. However, this sodium effect and the underlying mechanisms are still unclear for most GPCRs. Here, we identified sodium as a negative allosteric modulator of the ghrelin receptor GHSR (growth hormone secretagogue receptor). Combining 23Na-nuclear magnetic resonance (NMR), molecular dynamics, and mutagenesis, we provide evidence that, in GHSR, sodium binds to the allosteric site conserved in class A GPCRs. We further leveraged spectroscopic and functional assays to show that sodium binding shifts the conformational equilibrium toward the GHSR-inactive ensemble, thereby decreasing basal and agonist-induced receptor-catalyzed G protein activation. All together, these data point to sodium as an allosteric modulator of GHSR, making this ion an integral component of the ghrelin signaling machinery.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sódio
/
Receptores de Grelina
Idioma:
En
Revista:
Cell Rep
Ano de publicação:
2023
Tipo de documento:
Article