title: Long distance effect on ligand-gated ion channels extracellular domain may affect interactions with the intracellular machinery.
abstract: Modulation of receptor trafficking is critical for controlling neurotransmission. A γ2(R43Q) point mutation on GABAA receptor subunit is linked to epilepsy in human. We recently analyzed the effect of this amino-acid substitution on GABAA receptor trafficking and showed that this mutation as well as agonist application, both affecting GABAA receptor extracellular domain, have an effect on receptor endocytosis. By comparing homology models based on ligand gated ion channels in their active and resting states, we reveal that the γ2R43 domain is located in a loop that is affected by motion resulting from receptor activation. Taken together, these results suggest that endocytosis of GABAA receptors is linked to agonist induced conformational changes. We propose that ligand or modulator binding is followed by a whole chain of interconnections, including the intracellular domain, that may influence ligand-gated channel trafficking.
authors.affiliation: Univ. Bordeaux; INCIA; UMR 5287; Bordeaux, France ; CNRS; INCIA; UMR 5287; Bordeaux, France.
authors.forename: Maurice
authors.initials: M
authors.lastname: Garret
authors.affiliation: Univ. de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France ; CNRS; Institut des Maladies Neurodégénératives; UMR 5293; Bordeaux, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Boué-Grabot
authors.affiliation: Laboratoire de Biochimie Théorique (CNRS-Université Paris Diderot); Paris, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Taly
keywords: internalization, receptor model; trafficking