Cargando…

Channel opening and gating mechanism in AMPA-subtype glutamate receptors

AMPA-subtype ionotropic glutamate receptors mediate fast excitatory neurotransmission throughout the central nervous system. Gated by the neurotransmitter glutamate, AMPA receptors are critical for synaptic strength and dysregulation of AMPA receptor-mediated signaling is linked to numerous neurolog...

Descripción completa

Detalles Bibliográficos
Autores principales: Twomey, Edward C., Yelshanskaya, Maria V., Grassucci, Robert A., Frank, Joachim, Sobolevsky, Alexander I.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5743206/
https://www.ncbi.nlm.nih.gov/pubmed/28737760
http://dx.doi.org/10.1038/nature23479
Descripción
Sumario:AMPA-subtype ionotropic glutamate receptors mediate fast excitatory neurotransmission throughout the central nervous system. Gated by the neurotransmitter glutamate, AMPA receptors are critical for synaptic strength and dysregulation of AMPA receptor-mediated signaling is linked to numerous neurological diseases. Here, we use cryo-electron microscopy to solve the structures of AMPA receptor-auxiliary subunit complexes in the apo, antagonist and agonist-bound states and elucidate the iris-like mechanism of ion channel opening. The ion channel selectivity filter is formed by the extended portions of the re-entrant M2 loops, while the helical portions of M2 contribute to extensive hydrophobic interfaces between AMPA receptor subunits in the ion channel. We show how the permeation pathway changes upon channel opening and identify conformational changes throughout the entire AMPA receptor that accompany activation and desensitization. Our findings provide a framework for understanding gating across the family of ionotropic glutamate receptors and the role of AMPA receptors in excitatory neurotransmission.