Piezo1
Family:
Piezo channels; piezo-type mechanosensitive ion channel.
Members:
Piezo1 and Piezo2 in vertebrates, encoded by PIEZO1 and PIEZO2 genes, respectively.
Topology:
Piezo 1 is a trimeric mechanosensitive ion channel.Piezos are very large proteins with numerous (>14) predicted transmembrane (TM) domains per subunit.
Regulation and Function:
Piezo1 opens in response to mechanical stimuli such as shear stress and membrane stretch, allowing positively charged ions, including calcium, to flow into the cell.
Piezo1: Background information
Overview:
Piezo proteins are the pore-forming subunits of trimeric mechanosensitive ion channels that open in response to mechanical stimuli such as shear stress and membrane stretch, allowing positively charged ions, including calcium, to flow into the cell.
Data Sheet:
Gene:
PIEZO1
Human Protein:
UniProt Q92508
Tissue:
Expressed in tissues of hollow organs such as stomach, lungs, bladder, intestines, and endothelial cells lining the lumen of blood vessels. Also expressed red blood cells.
Function and pathology:
Gain-of-function (GOF) mutations in human Piezo1 cause hereditary xerocytosis (also known as dehydrated stomatocytosis), a familial anemia. Loss-of-function (LOF) mutations cause generalized lymphatic dysplasia characterized by varying degrees of anemia. Both channelopathies suggest a central role that Piezo1 plays in erythrocyte volume control.
Pathology:
Hereditary xerocytosis
Selective activators:
Yoda1; jedi1 (mouse); jedi1 (mouse)
Inhibitors:
Dooku1; ruthenium red; gadolinium
Assays:
Patch Clamp: whole cell, single channel, bilayers, mechanosensitive activation
Data and Applications
Piezo1 in red blood cells - Hereditary Xerocytosis
SyncroPatch 384PE (a predecessor model of the SyncroPatch 384) data and applications:
Whole-cell recordings of ion currents from RBCs of healthy donors and Hereditary Xerocytosis patients. Different mutations in the PIEZO1 gene were compared with controls. Aa The P50.2 mutation resulted in current conductance that was unchanged compared with transport controls, but showed increased conductance compared with general controls (Ab). The mutation P52.1 showed decreased conductance compared with transportation controls (Ba) and general controls (Bb).
Data from Petkova-Kirova et al, 2019.
Piezo1 in red blood cells - activation by Yoda1
SyncroPatch 384PE (a predecessor model of the SyncroPatch 384) data and applications:
Current response of Piezo1 activated by Yoda1 in patient cells with the novel PIEZO1 mutation (R2110W) compared to healthy red blood cells (RBCs). Shown are raw data traces (top) and statistical analysis of all measured cells, independent of their response to Yoda1 (bottom).
Data from Rotordam et al, 2019.
Piezo1 in Neuro2A cells - activation by Yoda1
SyncroPatch 384PE (a predecessor model of the SyncroPatch 384) data and applications:
Piezo1 channels endogenously expressed in Neuro2A cells were investigated on the SyncroPatch 384PE (a predecessor model of the SyncroPatch 384). A Screenshot of PatchControl 384 software during an experiment. B Statistical analysis of the currents at -100mV (left) and at 80 mV (right). 140 out of 384 Neuro2A cells (37%) passed the quality criteria and 85 cells (60% of the valid cells) were considered as Yoda1 responders.
Data from Rotordam et al, 2019.
Mechanical Stimulation of Piezo1 Channels
SyncroPatch 384 data and applications:
Cells were kindly provided by Prof. David Beech, University of Leeds, UK
HEK-hPiezo1, HEK-mPiezo1 and empty control HEK cells were activated in the same experiment by fluid shear stress: a small amount of solution was applied locally to the cell at 110µl/s pipetting speed in synch with a triggered recording of the voltage protocol.
Webinars
20.11.2018 | Webinar: The RELEVANCE of ion channel interplay – Voltage-activated channels in non-excitable cells
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i), 
Patchliner, 
Port-a-Patch Webinar
Date: November 20. 2018, 4:00 PM CET (11:00 AM EDT)
The Webinar focuses on the automated patch clamp assay development for the study of red blood cells in health and disease and the RELEVANCE project, an international consortium of 13 partners from academia, diagnostic labs, blood supply centers, and small companies that combines basic and translational research to improve prognostic, diagnostic and therapeutic approaches on red blood cell function in health and disease. To this end, Nanion contributes assays for the electrophysiological characterization of healthy and patient-derived red blood cells.
Podcast
Introducing Professor Lars Kaestner (Saarland University) - Red Blood Cells
In this edition of the podcast - we speak to Prof. Lars Kaestner and his work with Red Blood Cells; specifically looking at advances in diagnostic tools for Neuroacanthocytosis.
Publications
2019 - Red Blood Cell Membrane Conductance in Hereditary Haemolytic Anaemias
Patchliner publication in Frontiers in Physiology (2019)
Authors:
Petkova-Kirova P., Hertz L., Danielczok J., Huisjes R., Makhro A., Bogdanova A., del Mar Mañú-Pereira M., Vives Corrons J.-L., van Wijk R., Kaestner L.
2019 - A Novel Gain-Of-Function Mutation Of Piezo1 Is Functionally Affirmed In Red Blood Cells By High-Throughput Patch Clamp
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) publication in Haematologica (2019)
Authors:
Rotordam G.M., Fermo E., Becker N., Barcellini W., Brüggemann A., Fertig N., Egée S., Rapedius M., Bianchi P., Kaestner L.