Molecular mechanisms underlying menthol binding and activation of TRPM8 ion channel

• Published in: Nature communications Vol. 11; no. 1; pp. 3790 - 13
• Main Authors: Xu, Lizhen, Han, Yalan, Chen, Xiaoying, Aierken, Aerziguli, Wen, Han, Zheng, Wenjun, Wang, Hongkun, Lu, Xiancui, Zhao, Zhenye, Ma, Cheng, Liang, Ping, Yang, Wei, Yang, Shilong, Yang, Fan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29.07.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 631/57/2272/2273; 631/92/269/1153; Amino acids; Binding; Binding Sites - genetics; Biophysics; Energy; Fluorescence; Functional testing; HEK293 Cells; Humanities and Social Sciences; Humans; Hydroxyl groups; Ion Channel Gating - drug effects; Ion channels; Laboratories; Ligands; Medicine; Menthol; Menthol - chemistry; Menthol - pharmacology; Molecular Docking Simulation; Molecular Dynamics Simulation; Molecular modelling; multidisciplinary; Mutagenesis; Mutants; Mutation; Patch-Clamp Techniques; Point Mutation; Protein Binding; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Science; Science (multidisciplinary); Selectivity; Structure-Activity Relationship; Transient receptor potential proteins; Transmembrane domains; TRPM Cation Channels - agonists; TRPM Cation Channels - chemistry; TRPM Cation Channels - genetics
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-17582-x

Menthol in mints elicits coolness sensation by selectively activating TRPM8 channel. Although structures of TRPM8 were determined in the apo and liganded states, the menthol-bounded state is unresolved. To understand how menthol activates the channel, we docked menthol to the channel and systematically validated our menthol binding models with thermodynamic mutant cycle analysis. We observed that menthol uses its hydroxyl group as a hand to specifically grab with R842, and its isopropyl group as legs to stand on I846 and L843. By imaging with fluorescent unnatural amino acid, we found that menthol binding induces wide-spread conformational rearrangements within the transmembrane domains. By Φ analysis based on single-channel recordings, we observed a temporal sequence of conformational changes in the S6 bundle crossing and the selectivity filter leading to channel activation. Therefore, our study suggested a ‘grab and stand’ mechanism of menthol binding and how menthol activates TRPM8 at the atomic level. Menthol in mints elicits a coolness sensation by selective activation of TRPM8 ion channel. Here authors dock menthol to TRPM8 and systematically validate their menthol binding models with thermodynamic mutant cycle analysis in functional tests, and shed light on TRPM8 activation by menthol at the atomic level.