Sandbox Reserved 1653: Difference between revisions
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== Structure == | == Structure == | ||
==='''[https://en.wikipedia.org/wiki/Gating_(electrophysiology) Gating mechanism]'''=== | |||
Piezo 1 possesses delicate force sensing and mechanotransduction mechanisms. Here, we explain how Piezo channels sense and transduce mechanical force | |||
to gate the central ion-conducting pore. | |||
Piezo 1 can sense membrane tension through changes in the local curvature of the membrane and channel open in response to this change thanks to this structure. <ref name ="Piezo Senses Tension"/> | |||
Indeed, mPiezo trimer is non-planar conformation inside lipid bilayer, it produces a local dome-shaped deformation of the membrane. In cells, this membrane curvature project towards the cytoplasm and some electrostatics interactions stabilize the trimeric assembly in its curved conformation. | |||
<ref name = "nv article"> DOI 10.7554/eLife.33660</ref> | |||
The structure of Piezo1 offers a plausible explanation for the origin of its tension gating. Indeed, if the semi-spherical dome becomes flatter when Piezo opens, then the channel membrane system will expand thanks to the flexibility of the blades. | |||
However, because flattening does not constrain the pore to open wide, expansion and pore diameter are decoupled such that Piezo can exhibit is small conductance and cation selecticity, properties that are essential to its function.<ref name ="Piezo Senses Tension"/> <ref name="Fanny"> DOI 10.1038/s41586-019-1499-2</ref> | |||
image gating ?? ou morphing ?? | |||
==='''CED or cap'''=== | ==='''CED or cap'''=== | ||
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This position and connections of the beam render it an ideal structure for mechanical transmission from the distal THUs to the central ion-conducting pore. | This position and connections of the beam render it an ideal structure for mechanical transmission from the distal THUs to the central ion-conducting pore. | ||
The lever-like mechanotransduction apparatus constituted by the beam is possible because of its uneven movement. It displays large motion at the distal beam while subtle movement at the proximal end. It enables Piezo channels to effectively convert a large conformational change of the distal blades to a relatively slight opening of the central pore, allowing cation-selective permeation. The L1342 and L1345 residues of the beam act as a pivot to form the lever-like apparatus.<ref name="mechanogating"/> | The lever-like mechanotransduction apparatus constituted by the beam is possible because of its uneven movement. It displays large motion at the distal beam while subtle movement at the proximal end. It enables Piezo channels to effectively convert a large conformational change of the distal blades to a relatively slight opening of the central pore, allowing cation-selective permeation. The L1342 and L1345 residues of the beam act as a pivot to form the lever-like apparatus.<ref name="mechanogating"/> | ||
==='''Blade'''=== | ==='''Blade'''=== | ||
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for omnidirectional sensitivity <ref name="Piezo Senses Tension "/> <ref> DOI 10.7554/eLife.33660 </ref> | for omnidirectional sensitivity <ref name="Piezo Senses Tension "/> <ref> DOI 10.7554/eLife.33660 </ref> | ||
