scholarly journals Emerging Roles of Diacylglycerol-Sensitive TRPC4/5 Channels

Cells ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 218 ◽  
Author(s):  
Michael Mederos y Schnitzler ◽  
Thomas Gudermann ◽  
Ursula Storch
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Receptor Activation ◽  
Activation Mechanism ◽  
Regulatory Function ◽  
Cation Channels ◽  
Trpc Channels ◽  
Trpc Channel ◽  
Transient Receptor ◽  
Trpc5 Channels

Transient receptor potential classical or canonical 4 (TRPC4) and TRPC5 channels are members of the classical or canonical transient receptor potential (TRPC) channel family of non-selective cation channels. TRPC4 and TRPC5 channels are widely accepted as receptor-operated cation channels that are activated in a phospholipase C-dependent manner, following the Gq/11 protein-coupled receptor activation. However, their precise activation mechanism has remained largely elusive for a long time, as the TRPC4 and TRPC5 channels were considered as being insensitive to the second messenger diacylglycerol (DAG) in contrast to the other TRPC channels. Recent findings indicate that the C-terminal interactions with the scaffolding proteins Na+/H+ exchanger regulatory factor 1 and 2 (NHERF1 and NHERF2) dynamically regulate the DAG sensitivity of the TRPC4 and TRPC5 channels. Interestingly, the C-terminal NHERF binding suppresses, while the dissociation of NHERF enables, the DAG sensitivity of the TRPC4 and TRPC5 channels. This leads to the assumption that all of the TRPC channels are DAG sensitive. The identification of the regulatory function of the NHERF proteins in the TRPC4/5-NHERF protein complex offers a new starting point to get deeper insights into the molecular basis of TRPC channel activation. Future studies will have to unravel the physiological and pathophysiological functions of this multi-protein channel complex.

scholarly journals Elucidation of a TRPC6-TRPC5 Channel Cascade That Restricts Endothelial Cell Movement

2008 ◽  
Vol 19 (8) ◽  
pp. 3203-3211 ◽  
Author(s):  
Pinaki Chaudhuri ◽  
Scott M. Colles ◽  
Manjunatha Bhat ◽  
David R. Van Wagoner ◽  
Lutz Birnbaumer ◽  
...  
Keyword(s):  
Intracellular Calcium ◽  
Calcium Concentration ◽  
Transient Receptor Potential ◽  
Calcium Influx ◽  
Cell Movement ◽  
Receptor Potential ◽  
Receptor Activation ◽  
Calcium Stores ◽  
Trpc Channels ◽  
Transient Receptor

Canonical transient receptor potential (TRPC) channels are opened by classical signal transduction events initiated by receptor activation or depletion of intracellular calcium stores. Here, we report a novel mechanism for opening TRPC channels in which TRPC6 activation initiates a cascade resulting in TRPC5 translocation. When endothelial cells (ECs) are incubated in lysophosphatidylcholine (lysoPC), rapid translocation of TRPC6 initiates calcium influx that results in externalization of TRPC5. Activation of this TRPC6–5 cascade causes a prolonged increase in intracellular calcium concentration ([Ca2+]i) that inhibits EC movement. When TRPC5 is down-regulated with siRNA, the lysoPC-induced rise in [Ca2+]i is shortened and the inhibition of EC migration is lessened. When TRPC6 is down-regulated or EC from TRPC6−/− mice are studied, lysoPC has minimal effect on [Ca2+]i and EC migration. In addition, TRPC5 is not externalized in response to lysoPC, supporting the dependence of TRPC5 translocation on the opening of TRPC6 channels. Activation of this novel TRPC channel cascade by lysoPC, resulting in the inhibition of EC migration, could adversely impact on EC healing in atherosclerotic arteries where lysoPC is abundant.

Pharmacology of TRPC Channels and Its Potential in Cardiovascular and Metabolic Medicine

2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Robin S. Bon ◽  
David J. Wright ◽  
David J. Beech ◽  
Piruthivi Sukumar
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Annual Review ◽  
Publication Date ◽  
Trpc Channels ◽  
Trpc Channel ◽  
Channel Inhibition ◽  
Transient Receptor ◽  
Physical And Chemical ◽  
Trpc Proteins

Transient receptor potential canonical (TRPC) proteins assemble to form homo- or heterotetrameric, nonselective cation channels permeable to K+, Na+, and Ca2+. TRPC channels are thought to act as complex integrators of physical and chemical environmental stimuli. Although the understanding of essential physiological roles of TRPC channels is incomplete, their implication in various pathological mechanisms and conditions of the nervous system, kidneys, and cardiovascular system in combination with the lack of major adverse effects of TRPC knockout or TRPC channel inhibition is driving the search of TRPC channel modulators as potential therapeutics. Here, we review the most promising small-molecule TRPC channel modulators, the understanding of their mode of action, and their potential in the study and treatment of cardiovascular and metabolic disease. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Canonical transient receptor potential TRPC7 can function as both a receptor- and store-operated channel in HEK-293 cells

2004 ◽  
Vol 287 (6) ◽  
pp. C1709-C1716 ◽  
Author(s):  
Jean-Philippe Lièvremont ◽  
Gary St. J. Bird ◽  
James W. Putney
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Receptor Activation ◽  
Activation Mechanism ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
Canonical Transient Receptor Potential ◽  
Store Depletion ◽  
293 Cells ◽  
Transient Receptor

Previous studies on the activation mechanism of canonical transient receptor potential (TRPC) channels have often produced conflicting conclusions. All seven have been shown to be activated by phospholipase C (PLC)-coupled receptors, but TRPC1, TRPC2, TRPC3, TRPC4, TRPC5, and TRPC7 have also been proposed to function as store-operated channels. 1 1 Although PLC activation inevitably leads to activation of store-operated channels, in this report when we refer to PLC-activated channels, we mean those channels that are specifically activated by PLC independently of store depletion. In the case of TRPC3, the expression environment and the expression level appear to determine the mode of regulation. Evidence of a close structural relative of TRPC3, TRPC7, has been presented that this channel is activated by receptor activation or by store depletion. On the basis of previous findings for TRPC3, we reasoned that subtle differences in structure or expression conditions might account for the apparent distinct gating mechanisms of TRPC7. To reexamine the mode of activation of TRPC7, we stably and transiently transfected human embryonic kidney (HEK)-293 cells with cDNA encoding for human TRPC7. We examined the ability of a PLC-activating agonist and an intracellular Ca2+ store-depleting agent to activate these channels. Our findings demonstrate that when transiently expressed in HEK-293 cells, TRPC7 forms channels that are activated by PLC-stimulating agonists, but not by Ca2+ store depletion. However, when stably expressed in HEK-293 cells, TRPC7 can be activated by either Ca2+ store depletion or PLC activation. To our knowledge, this is the first demonstration of a channel protein that can be activated by both receptor- and store-operated modes in the same cell. In addition, the results reconcile the apparently conflicting findings of other laboratories regarding TRPC7 regulation.

scholarly journals Transient Receptor Potential Canonical Channels in Health and Disease: A 2020 Update

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 496
Author(s):  
Priya R. Kirtley ◽  
Gagandeep S. Sooch ◽  
Fletcher A. White ◽  
Alexander G. Obukhov
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Trpc Channels ◽  
Special Issue ◽  
25Th Anniversary ◽  
Trpc Channel ◽  
Transient Receptor Potential Canonical ◽  
Health And Disease ◽  
Transient Receptor

This 2020 Special Issue “TRPC channels” of Cells was dedicated to commemorating the 25th anniversary of discovery of the Transient Receptor Potential Canonical (TRPC) channel subfamily [...]

scholarly journals Dynamic NHERF interaction with TRPC4/5 proteins is required for channel gating by diacylglycerol

2016 ◽  
Vol 114 (1) ◽  
pp. E37-E46 ◽  
Author(s):  
Ursula Storch ◽  
Anna-Lena Forst ◽  
Franziska Pardatscher ◽  
Serap Erdogmus ◽  
Maximilian Philipp ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Transient Receptor Potential Channels ◽  
Activation Mechanism ◽  
Binding Motif ◽  
Trpc Channels ◽  
Channel Activity ◽  
C Terminus ◽  
Potential Channels ◽  
Transient Receptor

The activation mechanism of the classical transient receptor potential channels TRPC4 and -5 via the Gq/11 protein-phospholipase C (PLC) signaling pathway has remained elusive so far. In contrast to all other TRPC channels, the PLC product diacylglycerol (DAG) is not sufficient for channel activation, whereas TRPC4/5 channel activity is potentiated by phosphatidylinositol 4,5-bisphosphate (PIP2) depletion. As a characteristic structural feature, TRPC4/5 channels contain a C-terminal PDZ-binding motif allowing for binding of the scaffolding proteins Na+/H+ exchanger regulatory factor (NHERF) 1 and 2. PKC inhibition or the exchange of threonine for alanine in the C-terminal PDZ-binding motif conferred DAG sensitivity to the channel. Altogether, we present a DAG-mediated activation mechanism for TRPC4/5 channels tightly regulated by NHERF1/2 interaction. PIP2 depletion evokes a C-terminal conformational change of TRPC5 proteins leading to dynamic dissociation of NHERF1/2 from the C terminus of TRPC5 as a prerequisite for DAG sensitivity. We show that NHERF proteins are direct regulators of ion channel activity and that DAG sensitivity is a distinctive hallmark of TRPC channels.

scholarly journals Transient Receptor Potential Cation Channels and Calcium Dyshomeostasis in a Mouse Model Relevant to Malignant Hyperthermia

2020 ◽  
Vol 133 (2) ◽  
pp. 364-376 ◽  
Author(s):  
Jose Rafael Lopez ◽  
Vikas Kaura ◽  
Phillip Hopkins ◽  
Xiaochen Liu ◽  
Arkady Uryach ◽  
...  
Keyword(s):  
Mouse Model ◽  
Malignant Hyperthermia ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Muscle Cells ◽  
Cation Channels ◽  
Trpc Channels ◽  
Dependent Manner ◽  
Wild Type ◽  
Transient Receptor

Background Until recently, the mechanism for the malignant hyperthermia crisis has been attributed solely to sustained massive Ca2+ release from the sarcoplasmic reticulum on exposure to triggering agents. This study tested the hypothesis that transient receptor potential cation (TRPC) channels are important contributors to the Ca2+ dyshomeostasis in a mouse model relevant to malignant hyperthermia. Methods This study examined the mechanisms responsible for Ca2+ dyshomeostasis in RYR1-p.G2435R mouse muscles and muscle cells using calcium and sodium ion selective microelectrodes, manganese quench of Fura2 fluorescence, and Western blots. Results RYR1-p.G2435R mouse muscle cells have chronically elevated intracellular resting calcium and sodium and rate of manganese quench (homozygous greater than heterozygous) compared with wild-type muscles. After exposure to 1-oleoyl-2-acetyl-sn-glycerol, a TRPC3/6 activator, increases in intracellular resting calcium/sodium were significantly greater in RYR1-p.G2435R muscles (from 153 ± 11 nM/10 ± 0.5 mM to 304 ± 45 nM/14.2 ± 0.7 mM in heterozygotes P < 0.001] and from 251 ± 25 nM/13.9 ± 0.5 mM to 534 ± 64 nM/20.9 ± 1.5 mM in homozygotes [P < 0.001] compared with 123 ± 3 nM/8 ± 0.1 mM to 196 ± 27 nM/9.4 ± 0.7 mM in wild type). These increases were inhibited both by simply removing extracellular Ca2+ and by exposure to either a nonspecific (gadolinium) or a newly available, more specific pharmacologic agent (SAR7334) to block TRPC6- and TRPC3-mediated cation influx into cells. Furthermore, local pretreatment with SAR7334 partially decreased the elevation of intracellular resting calcium that is seen in RYR1-p.G2435R muscles during exposure to halothane. Western blot analysis showed that expression of TRPC3 and TRPC6 were significantly increased in RYR1-p.G2435R muscles in a gene–dose–dependent manner, supporting their being a primary molecular basis for increased sarcolemmal cation influx. Conclusions Muscle cells in knock-in mice expressing the RYR1-p.G2435R mutation are hypersensitive to TRPC3/6 activators. This hypersensitivity can be negated with pharmacologic agents that block TRPC3/6 activity. This reinforces the working hypothesis that transient receptor potential cation channels play a critical role in causing intracellular calcium and sodium overload in malignant hyperthermia–susceptible muscle, both at rest and during the malignant hyperthermia crisis. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Abstract 138: Transient Receptor Potential Channel C1 Deficiency Protects the Murine Heart from Pressure Overload

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Malini Seth ◽  
Zhu-Shan Zhang ◽  
Lan Mao ◽  
Jarrett Burch ◽  
Victoria Graham ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Transient Receptor Potential ◽  
Pressure Overload ◽  
Receptor Potential ◽  
Receptor Activation ◽  
Trpc Channels ◽  
Loss Of Function ◽  
Aortic Banding ◽  
Trpc1 Channels ◽  
Transient Receptor

Transient receptor potential canonical (TRPC) channels are non-selective cation channels that are activated in response to G-protein coupled receptor activation, depletion of internal stores and mechanical stretch. Recent reports suggest that cardiac TRPC channels mediate calcineurin dependent cardiac hypertrophy, yet few details exist as to the mechanism for activation of these channels. Here, we provide evidence that TRPC1 channels are the dominant TRPC channel in mouse cardiomyocytes and cardiac TRPC1 protein expression is augmented by seven fold following thoracic aortic banding (TAC). In addition, we provide the first loss of function studies to show that mice lacking TRPC1 channels developed significantly less cardiac hypertrophy following pressure overload induced by thoracic aortic banding suggesting that TRPC1 may confer deleterious calcium entry. Whole cell voltage clamp studies of isolated adult cardiomyocytes reveal a non-selective cation current that is induced by pressure overload that is absent in TRPC1−/− cardiomyocytes and in which TRP blockers such as gadolinium, 2-amino biphenyl boric acid and SKF96365 inhibit the TAC induced current. Finally, neonatal cardiomyocytes lacking functional TRPC1 display reduced TRPC current in response to cell stretch or angiotensin-II; the functional consequence of which includes reduced calcium oscillation frequency and reduced BNP expression. These results provide the first loss of function evidence for TRPC1 channels in cardiac hypertrophy and implicate TRPC1 as a stretch activated channel.

scholarly journals The Na+/Ca2+ Exchanger Inhibitor, KB-R7943, Blocks a Nonselective Cation Channel Implicated in Chemosensory Transduction

2009 ◽  
Vol 101 (3) ◽  
pp. 1151-1159 ◽  
Author(s):  
A. Pezier ◽  
Y. V. Bobkov ◽  
B. W. Ache
Keyword(s):  
Transient Receptor Potential ◽  
Single Channel ◽  
Receptor Potential ◽  
Trpc Channels ◽  
Dependent Manner ◽  
Open Probability ◽  
Olfactory Transduction ◽  
Voltage Dependent ◽  
Chemosensory Transduction ◽  
Transient Receptor

The mechanism(s) of olfactory transduction in invertebrates remains to be fully understood. In lobster olfactory receptor neurons (ORNs), a nonselective sodium-gated cation (SGC) channel, a presumptive transient receptor potential (TRP)C channel homolog, plays a crucial role in olfactory transduction, at least in part by amplifying the primary transduction current. To better determine the functional role of the channel, it is important to selectively block the channel independently of other elements of the transduction cascade, causing us to search for specific pharmacological blockers of the SGC channel. Given evidence that the Na+/Ca2+ exchange inhibitor, KB-R7943, blocks mammalian TRPC channels, we studied this probe as a potential blocker of the lobster SGC channel. KB-R7943 reversibly blocked the SGC current in both inside- and outside-out patch recordings in a dose- and voltage-dependent manner. KB-R7943 decreased the channel open probability without changing single channel amplitude. KB-R7943 also reversibly and in a dose-dependent manner inhibited both the odorant-evoked discharge of lobster ORNs and the odorant-evoked whole cell current. Our findings strongly imply that KB-R7943 potently blocks the lobster SGC channel and likely does so directly and not through its ability to block the Na+/Ca2+ exchanger.

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