Probing the gating mechanism of the mechanosensitive channel Piezol with the small molecule Yoda1

Piezo proteins are transmembrane ion channels which transduce many forms of mechanical stimuli into electrochemical signals. Their pore, formed by the assembly of three identical subunits, opens by an unknown mechanism. Here, to probe this mechanism, we investigate the interaction of Piezol with the small molecule agonist Yodal. By engineering chimeras between mouse Piezol and its Yodal-insensitive paralog Piezo2, we first identify a minimal protein region required for Yodal sensitivity. We next study the effect of Yodal on heterotrimeric Piezol channels harboring wild type subunits and Yodal-insensitive mutant subunits. Using calcium imaging and patch-clamp electrophysiology, we show that hybrid channels harboring as few as one Yodal-sensitive subunit exhibit Yodal sensitivity undistinguishable from homotrimeric wild type channels. Our results show that the Piezol pore remains fully open if only one subunit remains activated. This study sheds light on the gating and pharmacological mechanisms of a member of the Piezo channel family.