Activating mechanosensitive channels embedded in droplet interface bilayers using membrane asymmetry

Chemical Science ◽

10.1039/d0sc03889j ◽

2021 ◽

Author(s):

Robert Strutt ◽

James W. Hindley ◽

Jordan Gregg ◽

Paula J. Booth ◽

John D. Harling ◽

...

Keyword(s):

Channel Gating ◽

Mechanosensitive Channel ◽

Mechanosensitive Channels ◽

Membrane Asymmetry

Electrophysiology shows asymmetric lysophosphatidylcholine-containing DIBs trigger mechanosensitive channel gating, enabling user-designed, autonomous flux pathways in droplet networks.

Download Full-text

Lipid Bilayer Pressure Profiles and Mechanosensitive Channel Gating

Biophysical Journal ◽

10.1529/biophysj.103.034322 ◽

2004 ◽

Vol 86 (6) ◽

pp. 3496-3509 ◽

Cited By ~ 238

Author(s):

Justin Gullingsrud ◽

Klaus Schulten

Keyword(s):

Lipid Bilayer ◽

Channel Gating ◽

Mechanosensitive Channel ◽

Pressure Profiles

Download Full-text

The Purified Mechanosensitive Channel TREK-1 Is Directly Sensitive to Membrane Tension

Journal of Biological Chemistry ◽

10.1074/jbc.m113.478321 ◽

2013 ◽

Vol 288 (38) ◽

pp. 27307-27314 ◽

Cited By ~ 52

Author(s):

Catherine Berrier ◽

Alexandre Pozza ◽

Agnes de Lacroix de Lavalette ◽

Solenne Chardonnet ◽

Agnes Mesneau ◽

...

Keyword(s):

Lipid Bilayer ◽

Mechanosensitive Channel ◽

Positive Pressure ◽

Mechanosensitive Channels ◽

Membrane Tension ◽

Animal Cells ◽

Patch Clamp Recording ◽

Electrophysiological Properties ◽

Pressure Suction ◽

Pore Domain

Mechanosensitive channels are detected in all cells and are speculated to play a key role in many functions including osmoregulation, growth, hearing, balance, and touch. In prokaryotic cells, a direct gating of mechanosensitive channels by membrane tension was clearly demonstrated because the purified channels could be functionally reconstituted in a lipid bilayer. No such evidence has been presented yet in the case of mechanosensitive channels from animal cells. TREK-1, a two-pore domain K+ channel, was the first animal mechanosensitive channel identified at the molecular level. It is the target of a large variety of agents such as volatile anesthetics, neuroprotective agents, and antidepressants. We have produced the mouse TREK-1 in yeast, purified it, and reconstituted the protein in giant liposomes amenable to patch clamp recording. The protein exhibited the expected electrophysiological properties in terms of kinetics, selectivity, and pharmacology. Negative pressure (suction) applied through the pipette had no effect on the channel, but positive pressure could completely and reversibly close the channel. Our interpretation of these data is that the intrinsic tension in the lipid bilayer is sufficient to maximally activate the channel, which can be closed upon modification of the tension. These results indicate that TREK-1 is directly sensitive to membrane tension.

Download Full-text

The MscS and MscL Families of Mechanosensitive Channels Act as Microbial Emergency Release Valves

Journal of Bacteriology ◽

10.1128/jb.00576-12 ◽

2012 ◽

Vol 194 (18) ◽

pp. 4802-4809 ◽

Cited By ~ 119

Author(s):

Ian R. Booth ◽

Paul Blount

Keyword(s):

Structure And Function ◽

Mechanosensitive Channel ◽

Protective Mechanism ◽

Mechanosensitive Channels ◽

Additional Pressure ◽

Environmental Extremes ◽

Life Threatening ◽

And Function ◽

Compare And Contrast ◽

Plant Organelles

ABSTRACTSingle-celled organisms must survive exposure to environmental extremes. Perhaps one of the most variable and potentially life-threatening changes that can occur is that of a rapid and acute decrease in external osmolarity. This easily translates into several atmospheres of additional pressure that can build up within the cell. Without a protective mechanism against such pressures, the cell will lyse. Hence, most microbes appear to possess members of one or both families of bacterial mechanosensitive channels, MscS and MscL, which can act as biological emergency release valves that allow cytoplasmic solutes to be jettisoned rapidly from the cell. While this is undoubtedly a function of these proteins, the discovery of the presence of MscS homologues in plant organelles and MscL in fungus and mycoplasma genomes may complicate this simplistic interpretation of the physiology underlying these proteins. Here we compare and contrast these two mechanosensitive channel families, discuss their potential physiological roles, and review some of the most relevant data that underlie the current models for their structure and function.

Download Full-text