An inter-channel cooperative mechanism mediates PIEZO1's exquisite mechanosensitivity

Abstract

The bowl-shaped structure of PIEZO channels is predicted to flatten in response to mechanical stimuli, gating their pore open. However, how this unique structure allows them to detect exquisitely small changes in membrane tension remains unclear. Here, using pressure clamp electrophysiology, modeling, and molecular dynamics simulations, we show that the single channel open probability of PIEZO1 increases weakly with respect to pressure-induced tension. In contrast, when multiple channels are present in a membrane patch, channel open probability increases steeply as a function of the number of open channels. These cooperative effects are consistent with an inter-channel energetic repulsion due to the local membrane deformation created by the non-planar PIEZO structure. When channels open, this deformation shrinks, allowing open channels to diffuse closer to each other, thus delaying closure. This study reveals how PIEZO1 channels acquire their exceptional mechanosensitivity and suggests a possible mechanism by which cells could rapidly tune mechanosensitivity.