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. In previous studies, Piezo1 channels in lipid vesicles adopted a somewhat flattened conformation mediated by membrane curvature; however, the ion conduction pore remained closed. In line with the closed pore, Piezo1 channels do not open and conduct ions in the kind of lipids that were used in the structural studies. Here, we show first that Piezo1 channels in cell-derived membranes retain the ability to open and conduct ions under mechanical force, and second, that in cell-derived membrane vesicles, they adopt a more 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 complements mechanical force to activate Piezo1.