Monitoring the conformational ensemble and lipid environment of a mechanosensitive channel under cyclodextrin-induced membrane tension
Date
22/03/2024Author
Grant ID
RPG-2018-397
BB/R013780/1
BB/T017740/1
Keywords
Metadata
Show full item recordAbstract
Membrane forces shift the equilibria of mechanosensitive channels enabling them to convert mechanical cues into electrical signals. Molecular tools to stabilize and methods to capture their highly dynamic states are lacking. Cyclodextrins can mimic tension through the sequestering of lipids from membranes. Here we probe the conformational ensemble of MscS by EPR spectroscopy, the lipid environment with NMR, and function with electrophysiology under cyclodextrin-induced tension. We show the extent of MscS activation depends on the cyclodextrin-to-lipid ratio, and that lipids are depleted slower when MscS is present. This has implications in MscS’ activation kinetics when distinct membrane scaffolds such as nanodiscs or liposomes are used. We find MscS transits from closed to sub-conducting state(s) before it desensitizes, due to the lack of lipid availability in its vicinity required for closure. Our approach allows for monitoring tension-sensitive states in membrane proteins and screening molecules capable of inducing molecular tension in bilayers.
Citation
Lane , B J , Ma , Y , Yan , N , Wang , B , Ackermann , K , Karamanos , T K , Bode , B E & Pliotas , C 2024 , ' Monitoring the conformational ensemble and lipid environment of a mechanosensitive channel under cyclodextrin-induced membrane tension ' , Structure . https://doi.org/10.1016/j.str.2024.02.020
Publication
Structure
Status
Peer reviewed
ISSN
0969-2126Type
Journal article
Description
This project was supported by a Biotechnology and Biological Sciences Research Council (BBSRC) grant (BB/S018069/1) to C.P., who acknowledges support from the Wellcome Trust (WT) (219999/Z/19/Z) in the form of studentship for B.J.L. We also acknowledge support from the Chinese Scholarship Council (CSC) in the form of studentships for N.Y., Y.M., B.W., respectively. T.K.K. is supported by a Sir Henry Dale Fellowship funded by the WT and the Royal Society (223268/Z/21/Z). B.E.B. and C.P. thank the Leverhulme Trust (RPG-2018-397) for support. Funding from BBSRC (BB/R013780/1; BB/T017740/1) equipment grants enabled the purchase of the Qband Bruker pulse EPR spectrometer and University of Leeds funding the Bruker 950 MHz NMR spectrometer.Collections
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