Rearrangements of Piezo1 blade domains correlate with pore opening
PIEZO1 channels open in response to numerous mechanical stimuli, such as physical membrane deformations, which modulate the curvature of flexible domains called blades. Yet, whether different stimuli cause similar blade motions and whether these rearrangements correlate with pore opening remain unclear. Here, we scan local conformational changes along the PIEZO1 blade using fluorescent probes. We identify two distant probes, one intracellular proximal and the other extracellular distal, which independently and robustly respond to flow stimuli. Flow-induced signals from both probes exquisitely correlate with PIEZO1-dependent calcium influx and specifically increase in presence of fast-inactivating pore mutations. In contrast, both probes remain fluorimetrically silent to hypotonic shocks and indentations, two stimuli that otherwise evoke normal electrochemical responses in both engineered channels. This study reveals that flow-induced blade motions are functionally coupled to the pore and that at least two distant blade regions discriminate flow from two other stimuli, suggesting that PIEZO1 mobilizes distinct mechanisms to sense a broad range of mechanical cues. TeaserFluorimetric evidence suggests that different mechanical stimuli impart distinct rearrangements in PIEZO1s mechanosensory domains.