Biology subjects

Roettger, L.

Publications and source records attributed to Roettger, L..

3 recordsLinked to original sources

bioRxiv2026

State-dependent binding of the wedge domain controls inactivation of the mechanosensitive ion channel PIEZO1

The mechanically activated ion channel PIEZO1 transduces membrane tension into intracellular calcium signals and is critical for a wide range of physiological processes. Recent structural and functional studies have established a detailed framework for PIEZO1 activation, but the molecular mechanisms governing its rapid inactivation remain incompletely understood. Here, we examined the contribution of the intracellular wedge domain to PIEZO1 inactivation using site-directed mutagenesis, electrophysiological recordings and MINFLUX nanoscopy. We show that wedge deletion and disruption of specific {pi}-{pi} and cation-{pi} interactions between the wedge 1-helix and the pore module abolishes inactivation without impairing channel activation. Moreover, MINFLUX nanoscopy reveals that the wedge stabilizes a flat inactivated conformation of PIEZO1 and suggests that wedge dissociation is required for recovery from inactivation. Together, our data support a ball-and-chain-like mechanism with the wedge acting as a state-dependent inactivation particle that docks to the pore module to terminate channel activity during sustained mechanical stimulation.

physiology↗

bioRxiv2025

3D-MINFLUX nanoscopy reveals distinct allosteric mechanisms for activation and modulation of PIEZO1 by Yoda1

PIEZO1 underpins numerous physiological processes by which cells detect and respond to mechanical stimuli. The small molecule Yoda1 has become an indispensable tool that is frequently used for dissecting the role of PIEZO1 in physiological and pathological contexts, yet its mode of action remains incompletely understood. Here, using site-directed mutagenesis, electrophysiology, computational modelling and 3D-MINFLUX nanoscopy, we demonstrate that mutation of the previously proposed Yoda1 binding site, solely abolishes Yoda1-induced activation and channel flattening but preserves modulation of mechanically-evoked PIEZO1 currents, whereas mutation of F1715, which lines a transient binding cavity accessible only in the flattened PIEZO1 conformation, eliminated modulation without affecting Yoda-induced calcium entry. Thus, our data support a two-site induced-fit-like mechanism where Yoda first engages binding site-1 to promote blade flattening and pore opening and then transitions to a deeper binding site to modulate the mechanical activation threshold and inactivation kinetics. This revised model distinguishes discrete allosteric pathways for PIEZO1 activation versus modulation and provides a framework for the design of next-generation use-dependent PIEZO1 modulators.

pharmacology and toxicology↗

bioRxiv2024

Cluster nanoarchitecture and structural diversity of PIEZO1 in intact cells

The force-gated ion channel PIEZO1 confers mechanosensitivity to many cell types. While the structure and physiological roles of PIEZO1 are well-described, the subcellular distribution and the impact of the cellular microenvironment on PIEZO1 conformation and function are poorly understood. Here, using MINFLUX nanoscopy we demonstrate that PIEZO1 channels collectively deform the membrane into pit-shaped invaginations, thereby creating mechano-responsive microdomains capable of amplifying mechanical stimuli via subtle changes in their topology. Moreover, by measuring intramolecular distances in individual PIEZO1 channels with nanometer precision, we reveal subcellular compartment-specific differences in PIEZO1 conformation at rest and during activation that correlate with differences in PIEZO1 function and are possibly caused by differences in cytoskeletal architecture. Together, our data provide previously unrecognized insights into the complex interplay of forces that determine how PIEZO1 alters membrane shape and, vice versa, how the membrane together with the cytoskeleton affect the conformation and function of individual PIEZO1 channels. TeaserMINFLUX nanoscopy reveals subcellular distribution and conformational diversity of PIEZO1 channels in intact cells.

cell biology↗