Activation of the Mammalian Cells by Using Light-Sensitive Ion Channels

2012 ◽  
pp. 241-251
Author(s):  
Mandy Siu Yu Lung ◽  
Paul Pilowsky ◽  
Ewa M. Goldys
Keyword(s):  
Ion Channels ◽  
Mammalian Cells

scholarly journals Hydrogen, Bicarbonate, and Their Associated Exchangers in Cell Volume Regulation

2021 ◽  
Vol 9 ◽  
Author(s):  
Yizeng Li ◽  
Xiaohan Zhou ◽  
Sean X. Sun
Keyword(s):  
Ion Channels ◽  
Cell Volume ◽  
Volume Regulation ◽  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Cell Function ◽  
Water Flux ◽  
Cell Volume Regulation ◽  
Sodium Potassium ◽  
Before And After

Cells lacking a stiff cell wall, e.g., mammalian cells, must actively regulate their volume to maintain proper cell function. On the time scale that protein production is negligible, water flow in and out of the cell determines the cell volume variation. Water flux follows hydraulic and osmotic gradients; the latter is generated by various ion channels, transporters, and pumps in the cell membrane. Compared to the widely studied roles of sodium, potassium, and chloride in cell volume regulation, the effects of proton and bicarbonate are less understood. In this work, we use mathematical models to analyze how proton and bicarbonate, combined with sodium, potassium, chloride, and buffer species, regulate cell volume upon inhibition of ion channels, transporters, and pumps. The model includes several common, widely expressed ion transporters and focuses on obtaining generic outcomes. Results show that the intracellular osmolarity remains almost constant before and after cell volume change. The steady-state cell volume does not depend on water permeability. In addition, to ensure the stability of cell volume and ion concentrations, cells need to develop redundant mechanisms to maintain homeostasis, i.e., multiple ion channels or transporters are involved in the flux of the same ion species. These results provide insights for molecular mechanisms of cell volume regulation with additional implications for water-driven cell migration.

Delivering Ion Channels to Mammalian Cells by Membrane Fusion

2003 ◽  
pp. 275-296
Author(s):  
David C. Johns ◽  
Uta C. Hoppe ◽  
Eduardo Marbán ◽  
Brian O'Rourke
Keyword(s):  
Ion Channels ◽  
Membrane Fusion ◽  
Mammalian Cells

Use of a bicistronic GFP-expression vector to characterise ion channels after transfection in mammalian cells

1997 ◽  
Vol 434 (5) ◽  
pp. 632-638 ◽  
Author(s):  
Dominique Trouet ◽  
Bernd Nilius ◽  
Thomas Voets ◽  
G. Droogmans ◽  
J. Eggermont
Keyword(s):  
Ion Channels ◽  
Mammalian Cells ◽  
Expression Vector ◽  
Gfp Expression

scholarly journals PIEZO ion channel is required for root mechanotransduction in Arabidopsis thaliana

2020 ◽  
Author(s):  
Seyed A. R. Mousavi ◽  
Adrienne E Dubin ◽  
Wei-Zheng Zeng ◽  
Adam M. Coombs ◽  
Khai Do ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Ion Channels ◽  
Ion Channel ◽  
Mammalian Cells ◽  
Plant Root ◽  
Mechanical Strain ◽  
Root Tip ◽  
Root Tips ◽  
Mechanosensitive Ion Channels ◽  
Mechanical Constraints

SummaryPlant roots adapt to the mechanical constraints of the soil to grow and absorb water and nutrients. As in animal species, mechanosensitive ion channels in plants are proposed to transduce external mechanical forces into biological signals. However, the identity of these plant root ion channels remains unknown. Here, we show that Arabidopsis thaliana PIEZO (AtPIEZO) has preserved the function of its animal relatives and acts as an ion channel. We present evidence that plant PIEZO is highly expressed in the columella and lateral root cap cells of the root tip which experience robust mechanical strain during root growth. Deleting PIEZO from the whole plant significantly reduced the ability of its roots to penetrate denser barriers compared to wild type plants. piezo mutant root tips exhibited diminished calcium transients in response to mechanical stimulation, supporting a role of AtPIEZO in root mechanotransduction. Finally, a chimeric PIEZO channel that includes the C-terminal half of AtPIEZO containing the putative pore region was functional and mechanosensitive when expressed in naive mammalian cells. Collectively, our data suggest that Arabidopsis PIEZO plays an important role in root mechanotransduction and establishes PIEZOs as physiologically relevant mechanosensitive ion channels across animal and plant kingdoms.

scholarly journals Hydrogen sulfide upregulates acid-sensing ion channels via the MAPK-Erk1/2 signaling pathway

Function ◽  
2021 ◽  
Author(s):  
Zhong Peng ◽  
Stephan Kellenberger
Keyword(s):  
Hydrogen Sulfide ◽  
Ion Channels ◽  
Signaling Pathway ◽  
Cortical Neurons ◽  
Mammalian Cells ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Membrane Expression ◽  
Concentration Dependent Manner ◽  
Acid Sensing Ion Channels

Abstract Hydrogen sulfide (H2S) emerged recently as a new gasotransmitter and was shown to exert cellular effects by interacting with proteins, among them many ion channels. Acid-sensing ion channels (ASICs) are neuronal voltage-insensitive Na+ channels activated by extracellular protons. ASICs are involved in many physiological and pathological processes, such as fear conditioning, pain sensation and seizures. We characterize here the regulation of ASICs by H2S. In transfected mammalian cells, the H2S donor NaHS increased the acid-induced ASIC1a peak currents in a time- and concentration-dependent manner. Similarly, NaHS potentiated also the acid-induced currents of ASIC1b, ASIC2a and ASIC3. An upregulation induced by the H2S donors NaHS and GYY4137 was also observed with the endogenous ASIC currents of cultured hypothalamus neurons. In parallel with the effect on function, the total and plasma membrane expression of ASIC1a was increased by GYY4137, as determined in cultured cortical neurons. H2S also enhanced the phosphorylation of extracellular signal-regulated kinase, which belongs to the family of mitogen-activated protein kinases (MAPKs). Pharmacological blockade of the MAPK signaling pathway prevented the GYY4137-induced increase of ASIC function and expression, indicating that this pathway is required for ASIC regulation by H2S. Our study demonstrates that H2S regulates ASIC expression and function, and identifies the involved signaling mechanism. Since H2S shares several roles with ASICs, as e.g. facilitation of learning and memory, protection during seizure activity and modulation of nociception, it may be possible that H2S exerts some of these effects via a regulation of ASIC function.

scholarly journals High-throughput characterization of 309 photocrosslinker-bearing ASIC1a variants maps residues critical for channel function and pharmacology

2020 ◽  
Author(s):  
Nina Braun ◽  
Søren Friis ◽  
Christian Ihling ◽  
Andrea Sinz ◽  
Jacob Andersen ◽  
...  
Keyword(s):  
Ion Channels ◽  
High Throughput ◽  
Mammalian Cells ◽  
Great Precision ◽  
Pharmacological Modulation ◽  
Current Decay ◽  
Human Acid ◽  
Automated Patch Clamp ◽  
Insight Into

AbstractIncorporation of non-canonical amino acids (ncAAs) can endow proteins with novel functionalities, such as crosslinking or fluorescence. In ion channels, the function of these variants can be studied with great precision using standard electrophysiology, but this approach is typically labor intensive and low throughput. Here, we establish a high-throughput protocol to conduct functional and pharmacological investigations of ncAA-containing hASIC1a (human acid-sensing ion channel 1a) variants in transiently transfected mammalian cells. We introduce three different photocrosslinking ncAAs into 103 positions and assess the function of the resulting 309 variants with automated patch-clamp (APC). We demonstrate that the approach is efficient and versatile, as it is amenable to assessing even complex pharmacological modulation by peptides. The data show that the acidic pocket is a major determinant for current decay and live-cell crosslinking provides insight into the hASIC1a-psalmotoxin-1 interaction. Overall, this protocol will enable future APC-based studies of ncAA-containing ion channels in mammalian cells.

scholarly journals Cardiac optogenetics

2013 ◽  
Vol 304 (9) ◽  
pp. H1179-H1191 ◽  
Author(s):  
Emilia Entcheva
Keyword(s):  
Ion Channels ◽  
Mammalian Cells ◽  
High Specificity ◽  
Emerging Technology ◽  
Inhibitory Response ◽  
Research Activity ◽  
Spatiotemporal Resolution ◽  
And Control ◽  
The Impact

Optogenetics is an emerging technology for optical interrogation and control of biological function with high specificity and high spatiotemporal resolution. Mammalian cells and tissues can be sensitized to respond to light by a relatively simple and well-tolerated genetic modification using microbial opsins (light-gated ion channels and pumps). These can achieve fast and specific excitatory or inhibitory response, offering distinct advantages over traditional pharmacological or electrical means of perturbation. Since the first demonstrations of utility in mammalian cells (neurons) in 2005, optogenetics has spurred immense research activity and has inspired numerous applications for dissection of neural circuitry and understanding of brain function in health and disease, applications ranging from in vitro to work in behaving animals. Only recently (since 2010), the field has extended to cardiac applications with less than a dozen publications to date. In consideration of the early phase of work on cardiac optogenetics and the impact of the technique in understanding another excitable tissue, the brain, this review is largely a perspective of possibilities in the heart. It covers the basic principles of operation of light-sensitive ion channels and pumps, the available tools and ongoing efforts in optimizing them, overview of neuroscience use, as well as cardiac-specific questions of implementation and ideas for best use of this emerging technology in the heart.

The Diverse Physiological Functions of Mechanically Activated Ion Channels in Mammals

2021 ◽  
Vol 84 (1) ◽  
Author(s):  
Kate Poole
Keyword(s):  
Plasma Membrane ◽  
Ion Channels ◽  
Mammalian Cells ◽  
Annual Review ◽  
Publication Date ◽  
Research Focus ◽  
Ionic Flux ◽  
Touch Sensation ◽  
Mechanical Sensing

Many aspects of mammalian physiology are mechanically regulated. One set of molecules that can mediate mechanotransduction are the mechanically activated ion channels. These ionotropic force sensors are directly activated by mechanical inputs, resulting in ionic flux across the plasma membrane. While there has been much research focus on the role of mechanically activated ion channels in touch sensation and hearing, recent data have highlighted the broad expression pattern of these molecules in mammalian cells. Disruption of mechanically activated channels has been shown to impact ( a) the development of mechanoresponsive structures, ( b) acute mechanical sensing, and ( c) mechanically driven homeostatic maintenance in multiple tissue types. The diversity of processes impacted by these molecules highlights the importance of mechanically activated ion channels in mammalian physiology. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Ion channels and transporters in cancer. 1. Ion channels and cell proliferation in cancer

2011 ◽  
Vol 301 (2) ◽  
pp. C255-C265 ◽  
Author(s):  
Andrea Becchetti
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Ion Channels ◽  
Mammalian Cells ◽  
Malignant Cell ◽  
Cell Cycle Checkpoints ◽  
Environmental Signals ◽  
Functional Flexibility ◽  
Research Fields ◽  
Functional Relations

Progress through the cell mitotic cycle requires precise timing of the intrinsic molecular steps and tight coordination with the environmental signals that maintain a cell into the proper physiological context. Because of their great functional flexibility, ion channels coordinate the upstream and downstream signals that converge on the cell cycle machinery. Both voltage- and ligand-gated channels have been implicated in the control of different cell cycle checkpoints in normal as well as neoplastic cells. Ion channels mediate the calcium signals that punctuate the mitotic process, the cell volume oscillations typical of cycling cells, and the exocytosis of autocrine or angiogenetic factors. Other functions of ion channels in proliferation are still matter of debate. These may or may not depend on ion transport, as the channel proteins can form macromolecular complexes with growth factor and cell adhesion receptors. Direct conformational coupling with the cytoplasmic regulatory proteins is also possible. Derangement or relaxed control of the above processes can promote neoplasia. Specific types of ion channels have turned out to participate in the different stages of the tumor progression, in which cell heterogeneity is increased by the selection of malignant cell clones expressing the ion channel types that better support unrestrained growth. However, a comprehensive mechanistic picture of the functional relations between ion channels and cell proliferation is yet not available, partly because of the considerable experimental challenges offered by studying these processes in living mammalian cells. No doubt, such studies will constitute one of the most fruitful research fields for the next generation of cell physiologists.

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