Removal of the mechanoprotective influence of the cytoskeleton reveals PIEZO1 is gated by bilayer tension
نویسندگان
چکیده
Mechanosensitive ion channels are force-transducing enzymes that couple mechanical stimuli to ion flux. Understanding the gating mechanism of mechanosensitive channels is challenging because the stimulus seen by the channel reflects forces shared between the membrane, cytoskeleton and extracellular matrix. Here we examine whether the mechanosensitive channel PIEZO1 is activated by force-transmission through the bilayer. To achieve this, we generate HEK293 cell membrane blebs largely free of cytoskeleton. Using the bacterial channel MscL, we calibrate the bilayer tension demonstrating that activation of MscL in blebs is identical to that in reconstituted bilayers. Utilizing a novel PIEZO1-GFP fusion, we then show PIEZO1 is activated by bilayer tension in bleb membranes, gating at lower pressures indicative of removal of the cortical cytoskeleton and the mechanoprotection it provides. Thus, PIEZO1 channels must sense force directly transmitted through the bilayer.
منابع مشابه
Mechanical sensitivity of Piezo1 ion channels can be tuned by cellular membrane tension
Piezo1 ion channels mediate the conversion of mechanical forces into electrical signals and are critical for responsiveness to touch in metazoans. The apparent mechanical sensitivity of Piezo1 varies substantially across cellular environments, stimulating methods and protocols, raising the fundamental questions of what precise physical stimulus activates the channel and how its stimulus sensiti...
متن کاملMolecular basis of mechanotransduction in living cells.
The simplest cell-like structure, the lipid bilayer vesicle, can respond to mechanical deformation by elastic membrane dilation/thinning and curvature changes. When a protein is inserted in the lipid bilayer, an energetic cost may arise because of hydrophobic mismatch between the protein and bilayer. Localized changes in bilayer thickness and curvature may compensate for this mismatch. The pept...
متن کاملGating the mechanical channel Piezo1
Piezo1 is a eukaryotic cation-selective mechanosensitive ion channel. To understand channel function in vivo, we first need to analyze and compare the response in the whole cell and the patch. In patches, Piezo1 inactivates and the current is fit well by a 3-state model with a single pressure-dependent rate. However, repeated stimulation led to an irreversible loss of inactivation. Remarkably, ...
متن کاملMechanoprotection of the plasma membrane in neurons and other non-erythroid cells by the spectrin-based membrane skeleton.
Though the cytomechanics of spectrin have been explored only for erythrocytes, it is thought that the spectrin skeleton acts universally to support the otherwise mechanically vulnerable cell surface bilayer. Evidence for this role is beginning to accumulate and is reviewed here. Compared to that for erythrocytes, cells whose simplicity facilitates biophysical approaches, the evidence is indirec...
متن کاملMechanical Properties Analysis of Bilayer Euler-Bernoulli Beams Based on Elasticity Theory
This paper analyzes the effects of structures and loads on the static bending and free vibration problems of bilayer beams. Based on static mechanical equilibrium and energy equilibrium, the static and dynamic governing equations of bilayer beam are established. It is found that the value of the thickness ratio has a significant effect on the static and dynamic responses of the beam, and the st...
متن کامل