Interaction of the Mechanosensitive Channel, MscS, with the Membrane Bilayer through Lipid Intercalation into Grooves and Pockets

Tim Rasmussen, Akiko Rasmussen, Limin Yang, Corinna Kaul, Susan Black, Heloisa Galbiati, Stuart J Conway, Samantha Miller (Corresponding Author), Paul Blount (Corresponding Author), Ian Rylance Booth (Corresponding Author)

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

All membrane proteins have dynamic and intimate relationships with the lipids of the bilayer that may determine their activity. Mechanosensitive channels sense tension through their interaction with the lipids of the membrane. We have proposed a mechanism for the bacterial channel of small conductance, MscS, that envisages variable occupancy of pockets in the channel by lipid chains. Here, we analyze protein–lipid interactions for MscS by quenching of tryptophan fluorescence with brominated lipids. By this strategy, we define the limits of the bilayer for TM1, which is the most lipid exposed helix of this protein. In addition, we show that residues deep in the pockets, created by the oligomeric assembly, interact with lipid chains. On the cytoplasmic side, lipids penetrate as far as the pore-lining helices and lipid molecules can align along TM3b perpendicular to lipids in the bilayer. Cardiolipin, free fatty acids, and branched lipids can access the pockets where the latter have a distinct effect on function. Cholesterol is excluded from the pockets. We demonstrate that introduction of hydrophilic residues into TM3b severely impairs channel function and that even “conservative” hydrophobic substitutions can modulate the stability of the open pore. The data provide important insights into the interactions between phospholipids and MscS and are discussed in the light of recent developments in the study of Piezo1 and TrpV4.

Original languageEnglish
Pages (from-to)3339-3352
Number of pages14
JournalJournal of Molecular Biology
Volume431
Issue number17
Early online date4 Jun 2019
DOIs
Publication statusPublished - 9 Aug 2019

Fingerprint

Lipid Bilayers
Lipids
Membranes
Cardiolipins
Membrane Lipids
Nonesterified Fatty Acids
Tryptophan
Phospholipids
Membrane Proteins
Fluorescence
Cholesterol
Proteins

Keywords

  • lipid-protein interaction
  • fluorescence quenching
  • brominated lipids
  • tension sensing
  • electrophysiology

Cite this

Interaction of the Mechanosensitive Channel, MscS, with the Membrane Bilayer through Lipid Intercalation into Grooves and Pockets. / Rasmussen, Tim; Rasmussen, Akiko; Yang, Limin; Kaul, Corinna ; Black, Susan; Galbiati, Heloisa; Conway, Stuart J; Miller, Samantha (Corresponding Author); Blount, Paul (Corresponding Author); Booth, Ian Rylance (Corresponding Author).

In: Journal of Molecular Biology, Vol. 431, No. 17, 09.08.2019, p. 3339-3352.

Research output: Contribution to journalArticle

Rasmussen, Tim ; Rasmussen, Akiko ; Yang, Limin ; Kaul, Corinna ; Black, Susan ; Galbiati, Heloisa ; Conway, Stuart J ; Miller, Samantha ; Blount, Paul ; Booth, Ian Rylance. / Interaction of the Mechanosensitive Channel, MscS, with the Membrane Bilayer through Lipid Intercalation into Grooves and Pockets. In: Journal of Molecular Biology. 2019 ; Vol. 431, No. 17. pp. 3339-3352.
@article{52ec5a6b060a4b448fbfdbda78375792,
title = "Interaction of the Mechanosensitive Channel, MscS, with the Membrane Bilayer through Lipid Intercalation into Grooves and Pockets",
abstract = "All membrane proteins have dynamic and intimate relationships with the lipids of the bilayer that may determine their activity. Mechanosensitive channels sense tension through their interaction with the lipids of the membrane. We have proposed a mechanism for the bacterial channel of small conductance, MscS, that envisages variable occupancy of pockets in the channel by lipid chains. Here, we analyze protein–lipid interactions for MscS by quenching of tryptophan fluorescence with brominated lipids. By this strategy, we define the limits of the bilayer for TM1, which is the most lipid exposed helix of this protein. In addition, we show that residues deep in the pockets, created by the oligomeric assembly, interact with lipid chains. On the cytoplasmic side, lipids penetrate as far as the pore-lining helices and lipid molecules can align along TM3b perpendicular to lipids in the bilayer. Cardiolipin, free fatty acids, and branched lipids can access the pockets where the latter have a distinct effect on function. Cholesterol is excluded from the pockets. We demonstrate that introduction of hydrophilic residues into TM3b severely impairs channel function and that even “conservative” hydrophobic substitutions can modulate the stability of the open pore. The data provide important insights into the interactions between phospholipids and MscS and are discussed in the light of recent developments in the study of Piezo1 and TrpV4.",
keywords = "lipid-protein interaction, fluorescence quenching, brominated lipids, tension sensing, electrophysiology",
author = "Tim Rasmussen and Akiko Rasmussen and Limin Yang and Corinna Kaul and Susan Black and Heloisa Galbiati and Conway, {Stuart J} and Samantha Miller and Paul Blount and Booth, {Ian Rylance}",
note = "The authors are grateful to Tony Lee (Southampton) and Jim Naismith (St Andrews and Oxford) for helpful discussions. IRB, SM, AR, TR, SB were supported by a Wellcome Programme Grant (WT092552MA); HG and CK were funded by the EU FP7 ITN programme NICHE. The MscS F151W mutant was created by N. J. Hayward during his PhD studies at the University of Aberdeen. We thank Vanessa Flegler for assistance in the electron microscopy experiment. IRB was a recipient of a Leverhulme Emeritus Research Fellowship and a CEMI research grant from Caltech; PB was supported by Grant I-1420 of the Welch Foundation and Grant GM121780 from the National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or other funding organizations.",
year = "2019",
month = "8",
day = "9",
doi = "10.1016/j.jmb.2019.05.043",
language = "English",
volume = "431",
pages = "3339--3352",
journal = "Journal of Molecular Biology",
issn = "0022-2836",
publisher = "Academic Press Inc.",
number = "17",

}

TY - JOUR

T1 - Interaction of the Mechanosensitive Channel, MscS, with the Membrane Bilayer through Lipid Intercalation into Grooves and Pockets

AU - Rasmussen, Tim

AU - Rasmussen, Akiko

AU - Yang, Limin

AU - Kaul, Corinna

AU - Black, Susan

AU - Galbiati, Heloisa

AU - Conway, Stuart J

AU - Miller, Samantha

AU - Blount, Paul

AU - Booth, Ian Rylance

N1 - The authors are grateful to Tony Lee (Southampton) and Jim Naismith (St Andrews and Oxford) for helpful discussions. IRB, SM, AR, TR, SB were supported by a Wellcome Programme Grant (WT092552MA); HG and CK were funded by the EU FP7 ITN programme NICHE. The MscS F151W mutant was created by N. J. Hayward during his PhD studies at the University of Aberdeen. We thank Vanessa Flegler for assistance in the electron microscopy experiment. IRB was a recipient of a Leverhulme Emeritus Research Fellowship and a CEMI research grant from Caltech; PB was supported by Grant I-1420 of the Welch Foundation and Grant GM121780 from the National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or other funding organizations.

PY - 2019/8/9

Y1 - 2019/8/9

N2 - All membrane proteins have dynamic and intimate relationships with the lipids of the bilayer that may determine their activity. Mechanosensitive channels sense tension through their interaction with the lipids of the membrane. We have proposed a mechanism for the bacterial channel of small conductance, MscS, that envisages variable occupancy of pockets in the channel by lipid chains. Here, we analyze protein–lipid interactions for MscS by quenching of tryptophan fluorescence with brominated lipids. By this strategy, we define the limits of the bilayer for TM1, which is the most lipid exposed helix of this protein. In addition, we show that residues deep in the pockets, created by the oligomeric assembly, interact with lipid chains. On the cytoplasmic side, lipids penetrate as far as the pore-lining helices and lipid molecules can align along TM3b perpendicular to lipids in the bilayer. Cardiolipin, free fatty acids, and branched lipids can access the pockets where the latter have a distinct effect on function. Cholesterol is excluded from the pockets. We demonstrate that introduction of hydrophilic residues into TM3b severely impairs channel function and that even “conservative” hydrophobic substitutions can modulate the stability of the open pore. The data provide important insights into the interactions between phospholipids and MscS and are discussed in the light of recent developments in the study of Piezo1 and TrpV4.

AB - All membrane proteins have dynamic and intimate relationships with the lipids of the bilayer that may determine their activity. Mechanosensitive channels sense tension through their interaction with the lipids of the membrane. We have proposed a mechanism for the bacterial channel of small conductance, MscS, that envisages variable occupancy of pockets in the channel by lipid chains. Here, we analyze protein–lipid interactions for MscS by quenching of tryptophan fluorescence with brominated lipids. By this strategy, we define the limits of the bilayer for TM1, which is the most lipid exposed helix of this protein. In addition, we show that residues deep in the pockets, created by the oligomeric assembly, interact with lipid chains. On the cytoplasmic side, lipids penetrate as far as the pore-lining helices and lipid molecules can align along TM3b perpendicular to lipids in the bilayer. Cardiolipin, free fatty acids, and branched lipids can access the pockets where the latter have a distinct effect on function. Cholesterol is excluded from the pockets. We demonstrate that introduction of hydrophilic residues into TM3b severely impairs channel function and that even “conservative” hydrophobic substitutions can modulate the stability of the open pore. The data provide important insights into the interactions between phospholipids and MscS and are discussed in the light of recent developments in the study of Piezo1 and TrpV4.

KW - lipid-protein interaction

KW - fluorescence quenching

KW - brominated lipids

KW - tension sensing

KW - electrophysiology

UR - https://linkinghub.elsevier.com/retrieve/pii/S002228361930333X

UR - http://www.mendeley.com/research/interaction-mechanosensitive-channel-mscs-membrane-bilayer-through-lipid-intercalation-grooves-pocke

U2 - 10.1016/j.jmb.2019.05.043

DO - 10.1016/j.jmb.2019.05.043

M3 - Article

VL - 431

SP - 3339

EP - 3352

JO - Journal of Molecular Biology

JF - Journal of Molecular Biology

SN - 0022-2836

IS - 17

ER -