Lipid composition and mechanical force underlie multi-modal regulation of Piezo1 gating

Piezo1 ion channels are widely expressed cellular mechanosensors. They adopt an intrinsically curved shape when closed and are thought to open when mechanical forces applied to the membrane favor a more flattened conformation. By reconstituting Piezo1 channels into lipid vesicles, a flattened conformation has been determined, however, the ion conduction pore remained closed. In line with this observation, Piezo1 channels do not exhibit mechanical activation in the kind of lipids used in the structural studies. Here we show first that Piezo1 channels in cell-derived membranes retain functional mechanical gating, and second, that in cell-derived membranes they adopt a completely flattened disk shape associated with large conformational changes within and around the ion conduction pathway. These conformational changes occurring in cell-derived lipid membranes, suggest that mechanical force is necessary but insufficient, and that a specific membrane-derived cofactor apparently complements mechanical force to activate Piezo1.