The role of MscL amphipathic N terminus indicates a blueprint for bilayer-mediated gating of mechanosensitive channels
Abstract
The bacterial mechanosensitive channel MscL gates in response to membrane tension as a result of mechanical force transmitted directly to the channel from the lipid bilayer. MscL represents an excellent model system to study the basic biophysical principles of mechanosensory transduction. However, understanding of the essential structural components that transduce bilayer tension into channel gating remains incomplete. Here using multiple experimental and computational approaches, we demonstrate that the amphipathic N-terminal helix of MscL acts as a crucial structural element during tension-induced gating, both stabilizing the closed state and coupling the channel to the membrane. We propose that this may also represent a common principle in the gating cycle of unrelated mechanosensitive ion channels, allowing the coupling of channel conformation to membrane dynamics.
Additional Information
© 2016 Macmillan Publishers Limited, part of Springer Nature. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Received 24 December 2015. Accepted 18 May 2016. Published 22 June 2016. We thank Dr Ulrike Schumann from the laboratory of Professor Ian R. Booth (Aberdeen University) for the construction and kind supply of the DE3 strain of MJF612.We also thank Dr Yoshitaka Nakayama, Dr Yousef Jamali, Professor Qing-hua Qin and Dr Chai-Ann Ng, for their useful suggestions and comments. Computational resources equipped with the commercial Abaqus/Standard software were provided by the National Computational Infrastructure (NCI) via the Merit Allocation and ANU Partner Schemes, supported by the Australian Commonwealth Government. We also acknowledge the supercomputing facility at CSIRO. N.B. has been supported by a University International Postgraduate Award (UIPA) from the University of New South Wales. This project was supported by a grant and a Principal Research Fellowship to B.M. from the National Health and Medical Research Council of Australia. This work was also supported in part by funds from the Office of Health and Medical Research, NSW State Government and a grant from the NIH (GM063617). Author contributions: N.B., C.D.C, E.P., D.R., W.L. and B.M. designed research; N.B. and O.B. performed the simulations. B.C. and A.P.H. helped and supported MD simulations. N.B., C.D.C., E.P., M.D.C., P.S., J.W.D. and W.L performed the experiments; M.C., B.M. and E.P. carried out all the EPR-related experiments. P.R.R., N.B. and C.D.C. designed and carried out the mutagenesis and spheroplast formation. B.M., A.P.H., B.C., E.P. and D.R. contributed reagents/analytic tools; N.B., M.C., C.D.C., E.P., P.S. and B.M. analysed data; and N.B., C.D.C., A.P.H., E.P. and B.M. wrote the manuscript. All authors read and approved the final manuscript.Attached Files
Published - ncomms11984.pdf
Supplemental Material - ncomms11984-s1.pdf
Supplemental Material - ncomms11984-s2.avi
Supplemental Material - ncomms11984-s3.zip
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Additional details
- PMCID
- PMC4917966
- Eprint ID
- 68690
- Resolver ID
- CaltechAUTHORS:20160627-123940721
- University of New South Wales
- National Health and Medical Research Council (NHMRC)
- Office of Health and Medical Research (New South Wales)
- GM063617
- NIH
- Created
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2016-06-28Created from EPrint's datestamp field
- Updated
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2022-04-26Created from EPrint's last_modified field