scholarly journals Transient Receptor Potential Cation Channel Subfamily Vanilloid Member 3 is not Involved in Plasma Membrane Stretch-induced Intracellular Calcium Signaling in Merkel Cells

2015 ◽  
Vol 56 (4) ◽  
pp. 259-262
Author(s):  
Asuka Higashikawa ◽  
Yuki Kojima ◽  
Masaki Sato ◽  
Maki Kimura ◽  
Kazuhiro Ogura ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Calcium Signaling ◽  
Intracellular Calcium ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Cation Channel ◽  
Merkel Cells ◽  
Membrane Stretch ◽  
Intracellular Calcium Signaling ◽  
Transient Receptor

Opposing effects of podocin on the gating of podocyte TRPC6 channels evoked by membrane stretch or diacylglycerol

2013 ◽  
Vol 305 (3) ◽  
pp. C276-C289 ◽  
Author(s):  
Marc Anderson ◽  
Eun Young Kim ◽  
Henning Hagmann ◽  
Thomas Benzing ◽  
Stuart E. Dryer
Keyword(s):  
Plasma Membrane ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Stretch Activation ◽  
Gain Of Function ◽  
Gene Encoding ◽  
Membrane Stretch ◽  
Transient Receptor ◽  
Opposing Effects ◽  
Interfering Rna

Gain-of-function mutations in the transient receptor potential (TRP) cation channel subfamily C member 6 ( TRPC6) gene and mutations in the NPHS2 gene encoding podocin result in nephrotic syndromes. The purpose of this study was to determine the functional significance of biochemical interactions between these proteins. We observed that gating of TRPC6 channels in podocytes is markedly mechanosensitive and can be activated by hyposmotic stretch or indentation of the plasma membrane. Stretch activation of cationic currents was blocked by small interfering RNA knockdown of TRPC6, as well as by SKF-96365 or micromolar La3+. Stretch activation of podocyte TRPC6 persisted in the presence of inhibitors of phospholipase C (U-73122) and phospholipase A2 (ONO-RS-082). Robust stretch responses also persisted when recording electrodes contained guanosine 5′- O-(2-thiodiphosphate) at concentrations that completely suppressed responses to ANG II. Stretch responses were enhanced by cytochalasin D but were abolished by the peptide GsMTx4, suggesting that forces are transmitted to the channels through the plasma membrane. Podocin and TRPC6 interact at their respective COOH termini. Knockdown of podocin markedly increased stretch-evoked activation of TRPC6 but nearly abolished TRPC6 activation evoked by a diacylglycerol analog. These data suggest that podocin acts as a switch to determine the preferred mode of TRPC6 activation. They also suggest that podocin deficiencies will result in Ca2+ overload in foot processes, as with gain-of-function mutations in the TRPC6 gene. Finally, they suggest that mechanical activation of TRP family channels and the preferred mode of TRP channel activation may depend on whether members of the stomatin/prohibitin family of hairpin loop proteins are present.

scholarly journals Crosstalk Between Vascular Redox and Calcium Signaling in Hypertension Involves TRPM2 (Transient Receptor Potential Melastatin 2) Cation Channel

Hypertension ◽  
2020 ◽  
Vol 75 (1) ◽  
pp. 139-149 ◽  
Author(s):  
Rhéure Alves-Lopes ◽  
Karla B. Neves ◽  
Aikaterini Anagnostopoulou ◽  
Francisco J. Rios ◽  
Silvia Lacchini ◽  
...  
Keyword(s):  
Calcium Signaling ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Cation Channel ◽  
Transient Receptor Potential Melastatin ◽  
Transient Receptor

scholarly journals Transcriptomic Profiling of Ca2+ Transport Systems during the Formation of the Cerebral Cortex in Mice

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1800
Author(s):  
Alexandre Bouron
Keyword(s):  
Cerebral Cortex ◽  
Plasma Membrane ◽  
Transient Receptor Potential ◽  
Transmembrane Protein ◽  
Receptor Potential ◽  
Cytosolic Calcium ◽  
Cation Channel ◽  
Transport Systems ◽  
Transcriptomic Profiling ◽  
Transient Receptor

Cytosolic calcium (Ca2+) transients control key neural processes, including neurogenesis, migration, the polarization and growth of neurons, and the establishment and maintenance of synaptic connections. They are thus involved in the development and formation of the neural system. In this study, a publicly available whole transcriptome sequencing (RNA-Seq) dataset was used to examine the expression of genes coding for putative plasma membrane and organellar Ca2+-transporting proteins (channels, pumps, exchangers, and transporters) during the formation of the cerebral cortex in mice. Four ages were considered: embryonic days 11 (E11), 13 (E13), and 17 (E17), and post-natal day 1 (PN1). This transcriptomic profiling was also combined with live-cell Ca2+ imaging recordings to assess the presence of functional Ca2+ transport systems in E13 neurons. The most important Ca2+ routes of the cortical wall at the onset of corticogenesis (E11–E13) were TACAN, GluK5, nAChR β2, Cav3.1, Orai3, transient receptor potential cation channel subfamily M member 7 (TRPM7) non-mitochondrial Na+/Ca2+ exchanger 2 (NCX2), and the connexins CX43/CX45/CX37. Hence, transient receptor potential cation channel mucolipin subfamily member 1 (TRPML1), transmembrane protein 165 (TMEM165), and Ca2+ “leak” channels are prominent intracellular Ca2+ pathways. The Ca2+ pumps sarco/endoplasmic reticulum Ca2+ ATPase 2 (SERCA2) and plasma membrane Ca2+ ATPase 1 (PMCA1) control the resting basal Ca2+ levels. At the end of neurogenesis (E17 and onward), a more numerous and diverse population of Ca2+ uptake systems was observed. In addition to the actors listed above, prominent Ca2+-conducting systems of the cortical wall emerged, including acid-sensing ion channel 1 (ASIC1), Orai2, P2X2, and GluN1. Altogether, this study provides a detailed view of the pattern of expression of the main actors participating in the import, export, and release of Ca2+. This work can serve as a framework for further functional and mechanistic studies on Ca2+ signaling during cerebral cortex formation.

Inositol lipids and TRPC channel activation

2007 ◽  
Vol 74 ◽  
pp. 37-45 ◽  
Author(s):  
James W. Putney
Keyword(s):  
Plasma Membrane ◽  
Phospholipase C ◽  
Transient Receptor Potential ◽  
Calcium Signalling ◽  
Receptor Potential ◽  
Breakdown Product ◽  
Channel Activation ◽  
Inositol Lipids ◽  
Transient Receptor ◽  
Secondary Mechanism

The original hypothesis put forth by Bob Michell in his seminal 1975 review held that inositol lipid breakdown was involved in the activation of plasma membrane calcium channels or ‘gates’. Subsequently, it was demonstrated that while the interposition of inositol lipid breakdown upstream of calcium signalling was correct, it was predominantly the release of Ca2+ that was activated, through the formation of Ins(1,4,5)P3. Ca2+ entry across the plasma membrane involved a secondary mechanism signalled in an unknown manner by depletion of intracellular Ca2+ stores. In recent years, however, additional non-store-operated mechanisms for Ca2+ entry have emerged. In many instances, these pathways involve homologues of the Drosophila trp (transient receptor potential) gene. In mammalian systems there are seven members of the TRP superfamily, designated TRPC1–TRPC7, which appear to be reasonably close structural and functional homologues of Drosophila TRP. Although these channels can sometimes function as store-operated channels, in the majority of instances they function as channels more directly linked to phospholipase C activity. Three members of this family, TRPC3, 6 and 7, are activated by the phosphoinositide breakdown product, diacylglycerol. Two others, TRPC4 and 5, are also activated as a consequence of phospholipase C activity, although the precise substrate or product molecules involved are still unclear. Thus the TRPCs represent a family of ion channels that are directly activated by inositol lipid breakdown, confirming Bob Michell's original prediction 30 years ago.

scholarly journals Diacylglycerol activates the influx of extracellular cations in T-lymphocytes independently of intracellular calcium-store depletion and possibly involving endogenous TRP6 gene products

2002 ◽  
Vol 364 (1) ◽  
pp. 245-254 ◽  
Author(s):  
Alessandra GAMBERUCCI ◽  
Emanuele GIURISATO ◽  
Paola PIZZO ◽  
Maristella TASSI ◽  
Roberta GIUNTI ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
T Lymphocytes ◽  
Peripheral Blood ◽  
Transient Receptor Potential ◽  
Human Peripheral Blood ◽  
Receptor Potential ◽  
Animal Cells ◽  
Bivalent Cation ◽  
Intracellular Calcium Store ◽  
Transient Receptor

In Jurkat and human peripheral blood T-lymphocytes, 1-oleoyl-2-acetyl-sn-glycerol (OAG), a membrane-permeant analogue of diacylglycerol, activated the influx of Ca2+, Ba2+ and Sr2+. OAG also caused plasma-membrane depolarization in Ca2+-free media that was recovered by the addition of bivalent cation, indicating the activation of Na+ influx. OAG-induced cation influx was (i) mimicked by the natural dacylglycerol 1-stearoyl-2-arachidonyl-sn-glycerol, (ii) not blocked by inhibiting protein kinase C or in the absence of phopholipase C activity and (iii) blocked by La3+ and Gd3+. Differently from OAG, both thapsigargin and phytohaemagglutinin activated a potent influx of Ca2+, but little influx of Ba2+ and Sr2+. Moreover, the influx of Ca2+ activated by thapsigargin and that activated by OAG were additive. Furthermore, several drugs (i.e. econazole, SKF96365, carbonyl cyanide p-trifluoromethoxyphenylhydrazone, 2-aminoethoxy diphenylborate and calyculin-A), while inhibiting the influx of Ca2+ induced by both thapsigargin and phytohaemagglutinin, did not affect OAG-stimulated cation influx. Transient receptor potential (TRP) 3 and TRP6 proteins have been shown previously to be activated by diacylglycerol when expressed heterologously in animal cells [Hofmann, Obukhov, Schaefer, Harteneck, Gudermann and Schultz (1999) Nature (London) 397, 259–263]. In both Jurkat and peripheral blood T-lymphocytes, mRNA encoding TRP proteins 1, 3, 4 and 6 was detected by reverse transcriptase PCR, and the TRP6 protein was detected by Western blotting in a purified plasma-membrane fraction. We conclude that T-cells express a diacylglycerol-activated cation channel, unrelated to the channel involved in capacitative Ca2+ entry, and associated with the expression of TRP6 protein.

scholarly journals Two Decades of Evolution of Our Understanding of the Transient Receptor Potential Melastatin 2 (TRPM2) Cation Channel

Life ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 397
Author(s):  
Andras Szollosi
Keyword(s):  
Structure Function ◽  
Cell Activation ◽  
Transient Receptor Potential ◽  
Immune Cell ◽  
Receptor Potential ◽  
Cation Channel ◽  
Biophysical Properties ◽  
Vast Number ◽  
Transient Receptor Potential Melastatin ◽  
Transient Receptor

The transient receptor potential melastatin (TRPM) family belongs to the superfamily of TRP ion channels. It consists of eight family members that are involved in a plethora of cellular functions. TRPM2 is a homotetrameric Ca2+-permeable cation channel activated upon oxidative stress and is important, among others, for body heat control, immune cell activation and insulin secretion. Invertebrate TRPM2 proteins are channel enzymes; they hydrolyze the activating ligand, ADP-ribose, which is likely important for functional regulation. Since its cloning in 1998, the understanding of the biophysical properties of the channel has greatly advanced due to a vast number of structure–function studies. The physiological regulators of the channel have been identified and characterized in cell-free systems. In the wake of the recent structural biochemistry revolution, several TRPM2 cryo-EM structures have been published. These structures have helped to understand the general features of the channel, but at the same time have revealed unexplained mechanistic differences among channel orthologues. The present review aims at depicting the major research lines in TRPM2 structure-function. It discusses biophysical properties of the pore and the mode of action of direct channel effectors, and interprets these functional properties on the basis of recent three-dimensional structural models.

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