Mechanism of gating and partial agonist action in the glycine receptor.
Cell
; 184(4): 957-968.e21, 2021 02 18.
Article
en En
| MEDLINE
| ID: mdl-33567265
ABSTRACT
Ligand-gated ion channels mediate signal transduction at chemical synapses and transition between resting, open, and desensitized states in response to neurotransmitter binding. Neurotransmitters that produce maximum open channel probabilities (Po) are full agonists, whereas those that yield lower than maximum Po are partial agonists. Cys-loop receptors are an important class of neurotransmitter receptors, yet a structure-based understanding of the mechanism of partial agonist action has proven elusive. Here, we study the glycine receptor with the full agonist glycine and the partial agonists taurine and γ-amino butyric acid (GABA). We use electrophysiology to show how partial agonists populate agonist-bound, closed channel states and cryo-EM reconstructions to illuminate the structures of intermediate, pre-open states, providing insights into previously unseen conformational states along the receptor reaction pathway. We further correlate agonist-induced conformational changes to Po across members of the receptor family, providing a hypothetical mechanism for partial and full agonist action at Cys-loop receptors.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Activación del Canal Iónico
/
Receptores de Glicina
Límite:
Animals
/
Humans
Idioma:
En
Año:
2021
Tipo del documento:
Article