scholarly journals Analysis of the Mechanosensor Channel Functionality of TACAN

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Yiming Niu ◽  
Xiao Tao ◽  
George Vaisey ◽  
Paul D B Olinares ◽  
Hanan Alwaseem ◽  
...  
Keyword(s):  
Ion Channel ◽  
Physiological Function ◽  
Transmembrane Protein ◽  
Dimensional Structure ◽  
Mechanical Forces ◽  
Channel Activity ◽  
Fatty Acid Elongase ◽  
Membrane Reconstitution ◽  
3 Dimensional ◽  
Mechanosensitive Ion Channel

Mechanosensitive ion channels mediate transmembrane ion currents activated by mechanical forces. A mechanosensitive ion channel called TACAN was recently reported. We began to study TACAN with the intent to understand how it senses mechanical forces and functions as an ion channel. Using cellular patch-recording methods we failed to identify mechanosensitive ion channel activity. Using membrane reconstitution methods we found that TACAN, at high protein concentrations, produces heterogeneous conduction levels that are not mechanosensitive and are most consistent with disruptions of the lipid bilayer. We determined the structure of TACAN using single particle cryo-EM and observe that it forms a symmetrical dimeric transmembrane protein. Each protomer contains an intracellular-facing cleft with a coenzyme-A cofactor, confirmed by mass spectrometry. The TACAN protomers are related in 3-dimensional structure to a fatty acid elongase, ELOVL. Whilst its physiological function remains unclear, we anticipate that TACAN is not a mechanosensitive ion channel.

scholarly journals Analysis of the Mechanosensor Channel Functionality of TACAN

2021 ◽  
Author(s):  
Yiming Niu ◽  
Xiao Tao ◽  
George Vaisey ◽  
Paul Dominic B. Olinares ◽  
Hanan Alwaseem ◽  
...  
Keyword(s):  
Ion Channel ◽  
Physiological Function ◽  
Transmembrane Protein ◽  
Dimensional Structure ◽  
Mechanical Forces ◽  
Channel Activity ◽  
Fatty Acid Elongase ◽  
Membrane Reconstitution ◽  
3 Dimensional ◽  
Mechanosensitive Ion Channel

Mechanosensitive ion channels mediate transmembrane ion currents activated by mechanical forces. A mechanosensitive ion channel called TACAN was recently reported. We began to study TACAN with the intent to understand how it senses mechanical forces and functions as an ion channel. Using cellular patch-recording methods we failed to identify mechanosensitive ion channel activity. Using membrane reconstitution methods we found that TACAN, at high protein concentrations, produces non-selective, heterogeneous conduction levels that are not mechanosensitive and are most consistent with disruptions of the lipid bilayer. We determined the structure of TACAN using single particle cryo-EM and observe that it forms a symmetrical dimeric transmembrane protein. Each protomer contains an intracellular-facing cleft with a coenzyme-A co-factor, confirmed by mass spectrometry. The TACAN protomers are related in 3-dimensional structure to a fatty acid elongase, ELOVL. Whilst its physiological function remains unclear, we anticipate that TACAN is not a mechanosensitive ion channel.

scholarly journals Arabidopsis MSL10 Has a Regulated Cell Death Signaling Activity That Is Separable from Its Mechanosensitive Ion Channel Activity

2014 ◽  
Vol 26 (7) ◽  
pp. 3115-3131 ◽  
Author(s):  
Kira M. Veley ◽  
Grigory Maksaev ◽  
Elizabeth M. Frick ◽  
Emma January ◽  
Sarah C. Kloepper ◽  
...  
Keyword(s):  
Cell Death ◽  
Ion Channel ◽  
Channel Activity ◽  
Regulated Cell Death ◽  
Mechanosensitive Ion Channel ◽  
Cell Death Signaling ◽  
Signaling Activity

scholarly journals Fluorescence Microscopy of Piezo1 in Droplet Hydrogel Bilayers

2018 ◽  
Author(s):  
Oskar B. Jaggers ◽  
Pietro Ridone ◽  
Boris Martinac ◽  
Matthew A. B. Baker
Keyword(s):  
Ion Channels ◽  
Ion Channel ◽  
Simultaneous Recording ◽  
Mechanical Stimuli ◽  
Channel Activity ◽  
Channel Proteins ◽  
Mechanosensitive Ion Channel ◽  
Lymphatic Dysplasia ◽  
Hydrogel Bilayer

AbstractMechanosensitive ion channels are membrane gated pores which are activated by mechanical stimuli. The focus of this study is on Piezo1, a newly discovered, large, mammalian, mechanosensitive ion channel, which has been linked to diseases such as dehydrated hereditary stomatocytosis (Xerocytosis) and lymphatic dysplasia. Here we utilize an established in-vitro artificial bilayer system to interrogate single Piezo1 channel activity. The droplet-hydrogel bilayer (DHB) system uniquely allows the simultaneous recording of electrical activity and fluorescence imaging of labelled protein. We successfully reconstituted fluorescently labelled Piezo1 ion channels in DHBs and verified activity using electrophysiology in the same system. We demonstrate successful insertion and activation of hPiezo1-GFP in bilayers of varying composition. Furthermore, we compare the Piezo1 bilayer reconstitution with measurements of insertion and activation of KcsA channels to reproduce the channel conductances reported in the literature. Together, our results showcase the use of DHBs for future experiments allowing simultaneous measurements of ion channel gating while visualising the channel proteins using fluorescence.

scholarly journals Mechanosensitive ion channel Piezo2 is important for enterochromaffin cell response to mechanical forces

2016 ◽  
Vol 595 (1) ◽  
pp. 79-91 ◽  
Author(s):  
Fan Wang ◽  
Kaitlyn Knutson ◽  
Constanza Alcaino ◽  
David R. Linden ◽  
Simon J. Gibbons ◽  
...  
Keyword(s):  
Ion Channel ◽  
Cell Response ◽  
Mechanical Forces ◽  
Enterochromaffin Cell ◽  
Mechanosensitive Ion Channel

scholarly journals Coordination of WNT signaling and ciliogenesis during odontogenesis by piezo type mechanosensitive ion channel component 1

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Aya Miyazaki ◽  
Asuna Sugimoto ◽  
Keigo Yoshizaki ◽  
Keita Kawarabayashi ◽  
Kokoro Iwata ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Ion Channel ◽  
Wnt Signaling ◽  
Primary Cilia ◽  
Nuclear Translocation ◽  
Calcium Deposition ◽  
Marker Genes ◽  
Mechanical Forces ◽  
Odontoblast Differentiation ◽  
Mechanosensitive Ion Channel

Abstract Signal transmission from the mechanical forces to the various intracellular activities is a fundamental process during tissue development. Despite their critical role, the mechanism of mechanical forces in the biological process is poorly understood. In this study, we demonstrated that in the response to hydrostatic pressure (HP), the piezo type mechanosensitive ion channel component 1 (PIEZO1) is a primary mechanosensing receptor for odontoblast differentiation through coordination of the WNT expression and ciliogenesis. In stem cells from human exfoliated deciduous teeth (SHED), HP significantly promoted calcium deposition as well as the expression of odontogenic marker genes, PANX3 and DSPP, and WNT related-genes including WNT5b and WNT16, whereas HP inhibited cell proliferation and enhanced primary cilia expression. WNT signaling inhibitor XAV939 and primary cilia inhibitor chloral hydrate blocked the HP-induced calcium deposition. The PIEZO1 activator Yoda1 inhibited cell proliferation but induced ciliogenesis and WNT16 expression. Interestingly, HP and Yoda1 promoted nuclear translocation of RUNX2, whereas siRNA-mediated silencing of PIEZO1 decreased HP-induced nuclear translocation of RUNX2. Taken together, these results suggest that PIEZO1 functions as a mechanotransducer that connects HP signal to the intracellular signalings during odontoblast differentiation.

scholarly journals The 3-dimensional structure of a hepatitis C virus p7 ion channel by electron microscopy

2009 ◽  
Vol 106 (31) ◽  
pp. 12712-12716 ◽  
Author(s):  
P. Luik ◽  
C. Chew ◽  
J. Aittoniemi ◽  
J. Chang ◽  
P. Wentworth ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Ion Channel ◽  
Dimensional Structure ◽  
3 Dimensional

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

A Novel Reconstitution Method for Inducing the Formation of Regular 2-Dimensional Arrays of Membrane Proteins and Lipids

1988 ◽  
Vol 46 ◽  
pp. 152-153 ◽  
Author(s):  
A. Engel ◽  
A. Holzenburg ◽  
K. Stauffer ◽  
J. Rosenbusch ◽  
U. Aebi
Keyword(s):  
Membrane Proteins ◽  
Flow Rate ◽  
Lipid Membranes ◽  
Functional Characterization ◽  
Dimensional Structure ◽  
Electron Crystallography ◽  
Peltier Element ◽  
Protein Ratio ◽  
Precise Control ◽  
3 Dimensional

Reconstitution of solubilized and purified membrane proteins in the presence of phospholipids into vesicles allows their functions to be studied by simple bulk measurements (e.g. diffusion of differently sized solutes) or by conductance measurements after transformation into planar membranes. On the other hand, reconstitution into regular protein-lipid arrays, usually forming at a specific lipid-to-protein ratio, provides the basis for determining the 3-dimensional structure of membrane proteins employing the tools of electron crystallography.To refine reconstitution conditions for reproducibly inducing formation of large and highly ordered protein-lipid membranes that are suitable for both electron crystallography and patch clamping experiments aimed at their functional characterization, we built a flow-dialysis device that allows precise control of temperature and flow-rate (Fig. 1). The flow rate is generated by a peristaltic pump and can be adjusted from 1 to 500 ml/h. The dialysis buffer is brought to a preselected temperature during its travel through a meandering path before it enters the dialysis reservoir. A Z-80 based computer controls a Peltier element allowing the temperature profile to be programmed as function of time.

Structure and Interaction of Protamine by Dark Field Electron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 160-161
Author(s):  
D.P. Bazett-Jones ◽  
F.P. Ottensmeyer
Keyword(s):  
Electron Microscopy ◽  
Dark Field ◽  
Amino Acid Sequences ◽  
Dimensional Structure ◽  
3 Dimensional ◽  
Field Electron ◽  
Proposed Model ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Positively Charged

It has been shown for some time that it is possible to obtain images of small unstained proteins, with a resolution of approximately 5Å using dark field electron microscopy (1,2). Applying this technique, we have observed a uniformity in size and shape of the 2-dimensional images of pure specimens of fish protamines (salmon, herring (clupeine, Y-l) and rainbow trout (Salmo irideus)). On the basis of these images, a model for the 3-dimensional structure of the fish protamines has been proposed (2).The known amino acid sequences of fish protamines show stretches of positively charged arginines, separated by regions of neutral amino acids (3). The proposed model for protamine structure (2) consists of an irregular, right-handed helix with the segments of adjacent arginines forming the loops of the coil.

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