PIEZO1 and PIEZO2 Blade domains are differentially required for channel localization and function

Abstract

PIEZO1 and PIEZO2 are critical force-gated ion channels, detecting and transducing mechanical forces into ionic currents in many eukaryotic cell types, serving essential physiological roles. CryoEM and structure-function studies have revealed that three PIEZO monomers assemble as a 3-blade propeller, highlighting essential structural aspects for channel function. One of the most prominent features in PIEZO architecture is the Blade, a large membrane embedded domain that comprises 36 transmembrane fragments organized in 9 THU (Transmembrane Helix Units). Despite its suggested role in force transduction, the contribution of the Blade domain in channel physiology remains unclear. By systematically generating different truncated versions of PIEZO1 and PIEZO2, lacking parts of the Blade, we show the intact PIEZO1 Blade is essential for proper localization and function. Conversely, our results indicate the PIEZO2 Distal Blade segments (THU1-3) are dispensable for normal mechanical sensitivity. However, it plays a central role in channel stability and localization, containing a region that mediates the intracellular retention of a chimeric membrane protein. Our study indicates that, in addition to their biophysical properties, PIEZO1 and PIEZO2 also differ in the regulation of their localization, adding a new layer of control on PIEZO2 activity.