Close spatio-association of the transient receptor potential canonical 4 (TRPC4) channel with Gαi in TRPC4 activation process

2015 ◽  
Vol 308 (11) ◽  
pp. C879-C889 ◽  
Author(s):  
JongYun Myeong ◽  
Misun Kwak ◽  
Jae-Pyo Jeon ◽  
Chansik Hong ◽  
Ju-hong Jeon ◽  
...  
Keyword(s):  
G Protein ◽  
Molecular Mechanisms ◽  
Transient Receptor Potential ◽  
Hek293 Cells ◽  
Activation Process ◽  
Mutant Form ◽  
Muscarinic Agonist ◽  
Direct Binding ◽  
Fret Efficiency ◽  
Trpc4 Channel

TPRC channels are Ca2+-permeable, nonselective cation channels that are activated by a wide variety of stimuli, including G protein-coupled receptors (GPCRs). TRPC4 is commonly assumed to be activated by Gq/phospholipase C-coupled receptors. However, the other molecular mechanisms by which Gα proteins regulate TRPC4 remain unclear. Here, we found that Gαi2 regulates TRPC4 activation by direct binding. To investigate this mechanism, we used whole patch clamp and fluorescence resonance energy transfer (FRET). We tagged an isoform of mTRPC4 and G protein with CFP and YFP, respectively, and transiently transfected cells with the FRET pair. The FRET efficiency between TRPC4β-CFP and the constitutively active mutant form of Gαi2 was nearly 15% and was greater than that observed with wild-type Gαi2 (nearly 5%). Gβγ and the TRPC4 channel showed a FRET efficiency lower than 6%. In HEK293 cells transfected with the M2 muscarinic receptor, the application of carbachol increased the FRET efficiency between TRPC4β-CFP and Gαi2(WT)-YFP from 4.7 ± 0.4% ( n = 7) to 12.6 ± 1.4% ( n = 7). We also found that the TRPC4 channel directly interacts with Gαi2, but not with Gαq, when the channel is open. We analyzed the calcium levels in HEK293 cells expressing the channels and Gαi2 or Gαq using the calcium indicator YC6.1 (Yellow Cameleon 6.1). In response to the muscarinic agonist carbachol, M2-, Gαi2-, and TRPC4-expressing cells showed a prolonged Ca2+ influx compared with cells expressing only M2. Together, these data suggest that Gαi2 activates the TRPC4 channel by direct binding, which then induces Ca2+ entry.

scholarly journals Molecular Targets of Cannabidiol in Experimental Models of Neurological Disease

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5186 ◽  
Author(s):  
Serena Silvestro ◽  
Giovanni Schepici ◽  
Placido Bramanti ◽  
Emanuela Mazzon
Keyword(s):  
G Protein ◽  
Serotonin Receptor ◽  
Molecular Mechanisms ◽  
Transient Receptor Potential ◽  
Neurological Diseases ◽  
In Vivo Studies ◽  
Receptor Subtype ◽  
Transient Receptor Potential Vanilloid ◽  
Neuroprotective Effects ◽  
G Protein Coupled

Cannabidiol (CBD) is a non-psychoactive phytocannabinoid known for its beneficial effects including antioxidant and anti-inflammatory properties. Moreover, CBD is a compound with antidepressant, anxiolytic, anticonvulsant and antipsychotic effects. Thanks to all these properties, the interest of the scientific community for it has grown. Indeed, CBD is a great candidate for the management of neurological diseases. The purpose of our review is to summarize the in vitro and in vivo studies published in the last 15 years that describe the biochemical and molecular mechanisms underlying the effects of CBD and its therapeutic application in neurological diseases. CBD exerts its neuroprotective effects through three G protein coupled-receptors (adenosine receptor subtype 2A, serotonin receptor subtype 1A and G protein-coupled receptor 55), one ligand-gated ion channel (transient receptor potential vanilloid channel-1) and one nuclear factor (peroxisome proliferator-activated receptor γ). Moreover, the therapeutical properties of CBD are also due to GABAergic modulation. In conclusion, CBD, through multi-target mechanisms, represents a valid therapeutic tool for the management of epilepsy, Alzheimer’s disease, multiple sclerosis and Parkinson’s disease.

scholarly journals Monoterpenoids Induce Agonist-Specific Desensitization of Transient Receptor Potential Vanilloid-3 (TRPV3) ion Channels

2009 ◽  
Vol 12 (1) ◽  
pp. 116 ◽  
Author(s):  
Muhammad Azhar Sherkheli ◽  
Heike Benecke ◽  
Julia Franca Doerner ◽  
Olaf Kletke ◽  
A. K. Vogt-Eisele ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Transient Receptor Potential ◽  
Prolonged Exposure ◽  
Trp Channels ◽  
Receptor Potential ◽  
Hek293 Cells ◽  
Transient Receptor Potential Vanilloid ◽  
Neural Cells ◽  
Hacat Cells ◽  
Transient Receptor

Transient receptor potential vanilloid-3 (TRPV3) is a thermo-sensitive ion channel expressed in skin keratinocytes and in a variety of neural cells. It is activated by warmth as well as monoterpenoids including camphor, menthol, dihydrocarveol and 1,8-cineol. TRPV3 is described as a putative nociceptor and previous studies revealed sensitization of the channel during repeated short-term stimulation with different agonists. In the present investigation TRPV3 was transiently expressed in either Xenopus oocytes or HEK293 cells. Whole-cell voltage-clamp techniques were used to characterize the behavior of TRPV3 when challenged with different agonists. Similarly, a human keratinocyte-derived cell line (HaCaT cells) was used to monitor the behavior of native TRPV3 when challenged with different agonists. We report here that prolonged exposure (5-15 minutes) of monoterpenoids results in agonist-specific desensitization of TRPV3. Long-term exposure to camphor and 1,8-cineol elicits desensitizing currents in TRPV3 expressing oocytes, whereas the non-terpenoid agonist 2-APB induces sustained currents. Agonist-specific desensitization of endogenous TRPV3 was also found in HaCaT cells, which may be taken as a representative for the native system. Terpenoids have a long history of use in therapeutics, pharmaceuticals and cosmetics but knowledge about underpinning molecular mechanisms is incomplete. Our finding on agonist-induced desensitization of TRPV3 by some monoterpenoids displays a novel mechanism through which TRP channels could be functionally modulated. Therefore, we conclude that desensitization of TRPV3 channels might be the molecular basis of action for some of the medicinal properties of camphor and 1,8-cineol.

scholarly journals Regulator of G-protein signalling and GoLoco proteins suppress TRPC4 channel function via acting at Gαi/o

2016 ◽  
Vol 473 (10) ◽  
pp. 1379-1390 ◽  
Author(s):  
Jae-Pyo Jeon ◽  
Dhananjay P. Thakur ◽  
Jin-bin Tian ◽  
Insuk So ◽  
Michael X. Zhu
Keyword(s):  
G Protein ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Cation Channels ◽  
Transient Receptor Potential Canonical ◽  
Channel Function ◽  
G Protein Signalling ◽  
Trpc4 Channel ◽  
Transient Receptor

Transient receptor potential canonical 4 (TRPC4) form Ca2+-permeable cation channels activated downstream from receptor-activated Gi/o signalling. We show here that regulator of G-protein signalling (RGS) and Gαi/o-Loco (GoLoco) domain proteins suppress TRPC4 currents probably through regulation of lifetime and availability of Gαi/o-GTP, revealing new components of receptor-operated channel function.

scholarly journals Molecular mechanisms of metabotropic GABAB receptor function

2021 ◽  
Vol 7 (22) ◽  
pp. eabg3362
Author(s):  
Hamidreza Shaye ◽  
Benjamin Stauch ◽  
Cornelius Gati ◽  
Vadim Cherezov
Keyword(s):  
G Protein ◽  
Molecular Mechanisms ◽  
Gabab Receptor ◽  
Neurological Diseases ◽  
Activation Mechanism ◽  
Allosteric Modulators ◽  
Inhibitory Neurotransmitter ◽  
Therapeutic Drugs ◽  
G Protein Coupled ◽  
The Brain

Metabotropic γ-aminobutyric acid G protein–coupled receptors (GABAB) represent one of the two main types of inhibitory neurotransmitter receptors in the brain. These receptors act both pre- and postsynaptically by modulating the transmission of neuronal signals and are involved in a range of neurological diseases, from alcohol addiction to epilepsy. A series of recent cryo-EM studies revealed critical details of the activation mechanism of GABAB. Structures are now available for the receptor bound to ligands with different modes of action, including antagonists, agonists, and positive allosteric modulators, and captured in different conformational states from the inactive apo to the fully active state bound to a G protein. These discoveries provide comprehensive insights into the activation of the GABAB receptor, which not only broaden our understanding of its structure, pharmacology, and physiological effects but also will ultimately facilitate the discovery of new therapeutic drugs and neuromodulators.

G-protein-coupled receptors signalling at the cell nucleus: an emerging paradigmThis paper is one of a selection of papers published in this Special Issue, entitled The Nucleus: A Cell Within A Cell.

2006 ◽  
Vol 84 (3-4) ◽  
pp. 287-297 ◽  
Author(s):  
Fernand Gobeil ◽  
Audrey Fortier ◽  
Tang Zhu ◽  
Michela Bossolasco ◽  
Martin Leduc ◽  
...  
Keyword(s):  
G Protein ◽  
Cell Nucleus ◽  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Cell Metabolism ◽  
Hormone Secretion ◽  
G Protein Coupled Receptors ◽  
A Cell ◽  
G Protein Coupled

G-protein-coupled receptors (GPCRs) comprise a wide family of monomeric heptahelical glycoproteins that recognize a broad array of extracellular mediators including cationic amines, lipids, peptides, proteins, and sensory agents. Thus far, much attention has been given towards the comprehension of intracellular signaling mechanisms activated by cell membrane GPCRs, which convert extracellular hormonal stimuli into acute, non-genomic (e.g., hormone secretion, muscle contraction, and cell metabolism) and delayed, genomic biological responses (e.g., cell division, proliferation, and apoptosis). However, with respect to the latter response, there is compelling evidence for a novel intracrine mode of genomic regulation by GPCRs that implies either the endocytosis and nuclear translocation of peripheral-liganded GPCR and (or) the activation of nuclearly located GPCR by endogenously produced, nonsecreted ligands. A noteworthy example of the last scenario is given by heptahelical receptors that are activated by bioactive lipoids (e.g., PGE2 and PAF), many of which may be formed from bilayer membranes including those of the nucleus. The experimental evidence for the nuclear localization and signalling of GPCRs will be reviewed. We will also discuss possible molecular mechanisms responsible for the atypical compartmentalization of GPCRs at the cell nucleus, along with their role in gene expression.

scholarly journals Regulator of G Protein Signaling (RGS) and Goloco Proteins Suppress TRPC4 Channel Function via Acting at GAI/O

2016 ◽  
Vol 110 (3) ◽  
pp. 611a
Author(s):  
Jaepyo Jeon ◽  
Dhananjay P. Thakur ◽  
Jin Bin Tian ◽  
Michael X. Zhu
Keyword(s):  
G Protein ◽  
G Protein Signaling ◽  
Protein Signaling ◽  
Channel Function ◽  
Trpc4 Channel

scholarly journals Ionotropic and Metabotropic Proton-Sensing Receptors Involved in Airway Inflammation in Allergic Asthma

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Haruka Aoki ◽  
Chihiro Mogi ◽  
Fumikazu Okajima
Keyword(s):  
Airway Inflammation ◽  
Allergic Asthma ◽  
G Protein ◽  
Molecular Mechanisms ◽  
G Protein Coupled Receptors ◽  
Airway Smooth Muscle Cells ◽  
Transient Receptor Potential Vanilloid ◽  
Acidic Ph ◽  
Airway Responses ◽  
G Protein Coupled

An acidic microenvironment has been shown to evoke a variety of airway responses, including cough, bronchoconstriction, airway hyperresponsiveness (AHR), infiltration of inflammatory cells in the lung, and stimulation of mucus hyperproduction. Except for the participation of transient receptor potential vanilloid-1 (TRPV1) and acid-sensing ion channels (ASICs) in severe acidic pH (of less than 6.0)-induced cough and bronchoconstriction through sensory neurons, the molecular mechanisms underlying extracellular acidic pH-induced actions in the airways have not been fully understood. Recent studies have revealed that ovarian cancer G protein-coupled receptor 1 (OGR1)-family G protein-coupled receptors, which sense pH of more than 6.0, are expressed in structural cells, such as airway smooth muscle cells and epithelial cells, and in inflammatory and immune cells, such as eosinophils and dendritic cells. They function in a variety of airway responses related to the pathophysiology of inflammatory diseases, including allergic asthma. In the present review, we discuss the roles of ionotropic TRPV1 and ASICs and metabotropic OGR1-family G protein-coupled receptors in the airway inflammation and AHR in asthma and respiratory diseases.

Abstract 292: TRPA1 Promoting Myofibroblast Differentiation Mediate Pressure Overload-Induced Cardiac Fibrosis

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Shuang Li ◽  
Dong Han ◽  
Dachun Yang
Keyword(s):  
Knockout Mice ◽  
Molecular Mechanisms ◽  
Cardiac Fibrosis ◽  
Transient Receptor Potential ◽  
Transforming Growth Factor ◽  
Ventricular Remodeling ◽  
Cardiac Fibroblasts ◽  
Gene Transfection ◽  
Pressure Overload

Background: Hypertensive ventricular remodeling is a common cause of heart failure. Activation and accumulation of cardiac fibroblasts is the key contributors to this progression. Our previous studies indicate that transient receptor potential ankyrin 1 (TRPA1), a Ca 2+ channel necessary and sufficient, play a prominent role in ventricular remodeling. However, the molecular mechanisms regulating remain poorly understood. Methods: We used TRPA1 agonists cinnamaldehyde (CA) pretreatment and TRPA1 knockout mice to understand the role of TRPA1 in ventricular remodeling of hypertensive heart. We also examine the mechanisms through gene transfection and in vitro experiments. Results: TRPA1 overexpression fully activated myofibroblast transformation, while fibroblasts lacking TRPA1 were refractory to transforming growth factor β (TGF-β) -induced transdifferentiation. TRPA1 knockout mice showed hypertensive ventricular remodeling reversal following pressure overload. We found that the TGF-β induced TRPA1 expression through calcineurin-NFAT-Dyrk1A signaling pathway via the TRPA1 promoter. Once induced, TRPA1 activates the Ca 2+ -responsive protein phosphatase calcineurin, which itself induced myofibroblast transdifferentiation. Moreover, inhibition of calcineurin prevented TRPA1-dependent transdifferentiation. Conclusion: Our study provides the first evidence that TRPA1 regulation in cardiac fibroblasts transformation in response to hypertensive stimulation. The results suggesting a comprehensive pathway for myofibroblast formation in conjunction with TGF-β, Calcineurin, NFAT and Dyrk1A. Furthermore, these data indicate that negative modulation of cardiac fibroblast TRPA1 may represent a therapeutic strategy against hypertensive cardiac remodeling.

scholarly journals Interaction of CREB and PGC-1α Induces Fibronectin Type III Domain-Containing Protein 5 Expression in C2C12 Myotubes

2018 ◽  
Vol 50 (4) ◽  
pp. 1574-1584 ◽  
Author(s):  
Xiu-ying Yang ◽  
Margaret C.L. Tse ◽  
Xiang Hu ◽  
Wei-hua Jia ◽  
Guan-hua Du ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Molecular Mechanisms ◽  
Metabolic Effects ◽  
Hek293 Cells ◽  
Metabolic Phenotype ◽  
C2c12 Myotubes ◽  
Type Iii ◽  
Fibronectin Type Iii ◽  
Fibronectin Type Iii Domain ◽  
Fibronectin Type

Background/Aims: Fibronectin type III domain-containing protein 5 (FNDC5), also known as irisin, is a myokine secreted from muscle in response to exercise. However, the molecular mechanisms that regulate FNDC5 expression and the functional significance of irisn in skeletal muscle remain unknown. In this study, we explored the potential pathways that induce FNDC5 expression and delineated the metabolic effects of irisin on skeletal muscle. Methods: C2C12 myotubes were treated with drugs at various concentrations and durations. The expression and activation of genes were measured by real-time polymerase chain reaction (qRT-PCR) and Western blotting. Oxidative phosphorylation was quantified by measuring the oxygen consumption rate (OCR). Results: We found that the exercise-mimicking treatment (cAMP, forskolin and isoproterenol) increased Fndc5 expression in C2C12 myotubes. CREB over-expressed C2C12 myotubes displayed higher Fndc5 expression. CREB over-expression also promoted peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) expression. PGC-1α-induced Fndc5 expression was blocked when the dominant negative form of CREB (S133A) was present. PGC-1α mutation (S570A) also decreased Fndc5 expression. Immunoprecipitation showed that overexpressed PGC-1α complexed with CREB in HEK293 cells. C2C12 myotubes treated with forskolin also increased endogenous CREB and PGC-1α binding. Functionally, irisin treatment increased mitochondrial respiration, enhanced ATP production, promoted fatty acid oxidation but decreased glycolysis in myotubes. Conclusion: Our observation indicates that cAMP-mediated PGC-1α/CREB interaction triggers Fndc5 expression, which acts as an autocrine/paracrine to shape the metabolic phenotype of myotubes.

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