Structural basis for the ethanol action on G-protein-activated inwardly rectifying potassium channel 1 revealed by NMR spectroscopy

Yuki Toyama, Hanaho Kano, Yoko Mase, Mariko Yokogawa, Masanori Osawa, Ichio Shimada

研究成果: Article

5 引用 (Scopus)

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Ethanol consumption leads to a wide range of pharmacological effects by acting on the signaling proteins in the human nervous system, such as ion channels. Despite its familiarity and biological importance, very little is known about the molecular mechanisms underlying the ethanol action, due to extremely weak binding affinity and the dynamic nature of the ethanol interaction. In this research, we focused on the primary in vivo target of ethanol, G-protein-activated inwardly rectifying potassium channel (GIRK), which is responsible for the ethanol-induced analgesia. By utilizing solution NMR spectroscopy, we characterized the changes in the structure and dynamics of GIRK induced by ethanol binding. We demonstrated here that ethanol binds to GIRK with an apparent dissociation constant of 1.0 M and that the actual physiological binding site of ethanol is located on the cavity formed between the neighboring cytoplasmic regions of the GIRK tetramer. From the methyl-based NMR relaxation analyses, we revealed that ethanol activates GIRK by shifting the conformational equilibrium processes, which are responsible for the gating of GIRK, to stabilize an open conformation of the cytoplasmic ion gate. We suggest that the dynamic molecular mechanism of the ethanol-induced activation of GIRK represents a general model of the ethanol action on signaling proteins in the human nervous system.

元の言語English
ページ(範囲)3858-3863
ページ数6
ジャーナルProceedings of the National Academy of Sciences of the United States of America
115
発行部数15
DOI
出版物ステータスPublished - 2018 1 1

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