scholarly journals Glutathione depletion activates the yeast vacuolar transient receptor potential channel, Yvc1p, by reversible glutathionylation of specific cysteines

2016 ◽  
Vol 27 (24) ◽  
pp. 3913-3925 ◽  
Author(s):  
Avinash Chandel ◽  
Krishna K. Das ◽  
Anand K. Bachhawat
Keyword(s):  
Calcium Channel ◽  
Transient Receptor Potential ◽  
Transmembrane Domain ◽  
Trp Channels ◽  
Calcium Influx ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Glutathione Depletion ◽  
Glutathione S Transferase ◽  
Transient Receptor

Glutathione depletion and calcium influx into the cytoplasm are two hallmarks of apoptosis. We have been investigating how glutathione depletion leads to apoptosis in yeast. We show here that glutathione depletion in yeast leads to the activation of two cytoplasmically inward-facing channels: the plasma membrane, Cch1p, and the vacuolar calcium channel, Yvc1p. Deletion of these channels partially rescues cells from glutathione depletion–induced cell death. Subsequent investigations on the Yvc1p channel, a homologue of the mammalian TRP channels, revealed that the channel is activated by glutathionylation. Yvc1p has nine cysteine residues, of which eight are located in the cytoplasmic regions and one on the transmembrane domain. We show that three of these cysteines, Cys-17, Cys-79, and Cys-191, are specifically glutathionylated. Mutation of these cysteines to alanine leads to a loss in glutathionylation and a concomitant loss in calcium channel activity. We further investigated the mechanism of glutathionylation and demonstrate a role for the yeast glutathione S-transferase Gtt1p in glutathionylation. Yvc1p is also deglutathionylated, and this was found to be mediated by the yeast thioredoxin, Trx2p. A model for redox activation and deactivation of the yeast Yvc1p channel is presented.

Intragastric administration of capsiate, a transient receptor potential channel agonist, triggers thermogenic sympathetic responses

2011 ◽  
Vol 110 (3) ◽  
pp. 789-798 ◽  
Author(s):  
Kaori Ono ◽  
Masako Tsukamoto-Yasui ◽  
Yoshiko Hara-Kimura ◽  
Naohiko Inoue ◽  
Yoshihito Nogusa ◽  
...  
Keyword(s):  
Sympathetic Nerve ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Low Frequency ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Intragastric Administration ◽  
Brown Adipose ◽  
Reflex Arc ◽  
Transient Receptor

The sympathetic thermoregulatory system controls the magnitude of adaptive thermogenesis in correspondence with the environmental temperature or the state of energy intake and plays a key role in determining the resultant energy storage. However, the nature of the trigger initiating this reflex arc remains to be determined. Here, using capsiate, a digestion-vulnerable capsaicin analog, we examined the involvement of specific activation of transient receptor potential (TRP) channels within the gastrointestinal tract in the thermogenic sympathetic system by measuring the efferent activity of the postganglionic sympathetic nerve innervating brown adipose tissue (BAT) in anesthetized rats. Intragastric administration of capsiate resulted in a time- and dose-dependent increase in integrated BAT sympathetic nerve activity (SNA) over 180 min, which was characterized by an emergence of sporadic high-activity phases composed of low-frequency bursts. This increase in BAT SNA was abolished by blockade of TRP channels as well as of sympathetic ganglionic transmission and was inhibited by ablation of the gastrointestinal vagus nerve. The activation of SNA was delimited to BAT and did not occur in the heart or pancreas. These results point to a neural pathway enabling the selective activation of the central network regulating the BAT SNA in response to a specific stimulation of gastrointestinal TRP channels and offer important implications for understanding the dietary-dependent regulation of energy metabolism and control of obesity.

scholarly journals Differential epitope masking reveals synapse-specific complexes of TRPM1

2018 ◽  
Vol 35 ◽  
Author(s):  
MELINA A. AGOSTO ◽  
IVAN A. ANASTASSOV ◽  
THEODORE G. WENSEL
Keyword(s):  
Binding Site ◽  
Transient Receptor Potential ◽  
Transmembrane Domain ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Bipolar Cells ◽  
Mouse Retina ◽  
Binding Partners ◽  
Transient Receptor ◽  
Quantitative Immunoblotting

AbstractThe transient receptor potential channel TRPM1 is required for synaptic transmission between photoreceptors and the ON subtype of bipolar cells (ON-BPC), mediating depolarization in response to light. TRPM1 is present in the somas and postsynaptic dendritic tips of ON-BPCs. Monoclonal antibodies generated against full-length TRPM1 were found to have differential labeling patterns when used to immunostain the mouse retina, with some yielding reduced labeling of dendritic tips relative to the labeling of cell bodies. Epitope mapping revealed that those antibodies that poorly label the dendritic tips share a binding site (N2d) in the N-terminal arm near the transmembrane domain. A major splice variant of TRPM1 lacking exon 19 does not contain the N2d binding site, but quantitative immunoblotting revealed no enrichment of this variant in synaptsomes. One explanation of the differential labeling is masking of the N2d epitope by formation of a synapse-specific multiprotein complex. Identifying the binding partners that are specific for the fraction of TRPM1 present at the synapses is an ongoing challenge for understanding TRPM1 function.

scholarly journals Design, Synthesis and In Vitro Experimental Validation of Novel TRPV4 Antagonists Inspired by Labdane Diterpenes

Marine Drugs ◽  
2020 ◽  
Vol 18 (10) ◽  
pp. 519
Author(s):  
Sarah Mazzotta ◽  
Gabriele Carullo ◽  
Aniello Schiano Moriello ◽  
Pietro Amodeo ◽  
Vincenzo Di Marzo ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Calcium Influx ◽  
Biological Activities ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Design Synthesis ◽  
Cellular Assays ◽  
Transient Receptor ◽  
Trpv4 Channel

Labdane diterpenes are widespread classes of natural compounds present in variety of marine and terrestrial organisms and plants. Many of them represents “natural libraries” of compounds with interesting biological activities due to differently functionalized drimane nucleus exploitable for potential pharmacological applications. The transient receptor potential channel subfamily V member 4 (TRPV4) channel has recently emerged as a pharmacological target for several respiratory diseases, including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Inspired by the labdane-like bicyclic core, a series of homodrimane-derived esters and amides was designed and synthesized by modifying the flexible tail in position 1 of (+)-sclareolide, an oxidized derivative of the bioactive labdane-type diterpene sclareol. The potency and selectivity towards rTRPV4 and hTRPV1 receptors were assessed by calcium influx cellular assays. Molecular determinants critical for eliciting TRPV4 antagonism were identified by structure-activity relationships. Among the selective TRPV4 antagonists identified, compound 6 was the most active with an IC50 of 5.3 μM. This study represents the first report of semisynthetic homodrimane TRPV4 antagonists, selective over TRPV1, and potentially useful as pharmacological tools for the development of novel TRPV4 channel modulators.

Calciotropic and Magnesiotropic TRP Channels

Physiology ◽  
2008 ◽  
Vol 23 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Joost G. J. Hoenderop ◽  
René J. M. Bindels
Keyword(s):  
Divalent Cation ◽  
Molecular Mechanisms ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Significant Progress ◽  
Functional Aspects ◽  
Health And Disease ◽  
Transient Receptor

Significant progress has been made into our understanding of the molecular mechanisms responsible for Ca2+ and Mg2+ homeostasis. Members of the transient receptor potential channel (TRP) superfamily proved essential to the maintenance of divalent cation levels by regulating their absorption from renal and intestinal lumina. This review highlights the molecular and functional aspects of these new calciotropic and magnesiotropic TRPs in health and disease.

scholarly journals The Calcium-Dependent Protease Calpain-1 Links TRPC6 Activity to Podocyte Injury

2018 ◽  
Vol 29 (8) ◽  
pp. 2099-2109 ◽  
Author(s):  
Kim A.T. Verheijden ◽  
Ramon Sonneveld ◽  
Marinka Bakker-van Bebber ◽  
Jack F.M. Wetzels ◽  
Johan van der Vlag ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Calcium Influx ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Slit Diaphragm ◽  
Calpain Inhibitor ◽  
Podocyte Injury ◽  
Calcium Dependent ◽  
Transient Receptor ◽  
Calcineurin Activity

BackgroundThe hallmark of podocytopathies, such as FSGS, is podocyte injury resulting in proteinuria. Transient receptor potential channel C6 (TRPC6) is a calcium-conducting ion channel expressed at the slit diaphragm. TRPC6 gain-of-function mutations and glomerular TRPC6 overexpression are associated with proteinuria. However, the pathways linking TRPC6 to podocyte injury, which is characterized by loss of the slit diaphragm protein nephrin, activation of several intracellular pathways (including calcineurin-NFAT signaling), and cytoskeletal rearrangement, remain elusive.MethodsWe tested whether the calcium-dependent protease calpain-1 mediates TRPC6-dependent podocyte injury in human and experimental FSGS and cultured podocytes.ResultsCompared with kidneys of healthy controls, kidneys of patients with FSGS had increased TRPC6 expression, increased calpain and calcineurin activity, and reduced expression of the calpain target Talin-1, which links the actin cytoskeleton to integrins and is critical for podocyte cytoskeletal stability. In a rat model of human FSGS, increased glomerular and urinary calpain activity associated with reduced Talin-1 abundance, enhanced calcineurin activity, and increased proteinuria. Treatment with the calpain inhibitor calpeptin prevented these effects. In cultured podocytes, pharmacologic stimulation of TRPC6-dependent calcium influx increased calpain-1 and calcineurin activity and reduced Talin-1 expression, and knockdown of TRPC6 or calpain-1 prevented these effects.ConclusionsWe elucidated a novel mechanism that links TRPC6 activity to calpain-1 activation and through Talin-1 loss and possibly, calcineurin activation, the podocyte injury characterizing FSGS. Therefore, calpain-1 and/or TRPC6 inhibition could be future therapeutic options to treat patients with FSGS or other podocytopathies.

Transient Receptor Potential Channel TRPM8 Agonists Stimulate Calcium Influx and Neurotensin Secretion in Neuroendocrine Tumor Cells

2007 ◽  
Vol 85 (2) ◽  
pp. 81-92 ◽  
Author(s):  
Stefan Mergler ◽  
Mathias Z. Strowski ◽  
Simone Kaiser ◽  
Thomas Plath ◽  
Yvonne Giesecke ◽  
...  
Keyword(s):  
Neuroendocrine Tumor ◽  
Tumor Cells ◽  
Transient Receptor Potential ◽  
Calcium Influx ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Transient Receptor

scholarly journals TRPC5 Does Not Cause or Aggravate Glomerular Disease

2017 ◽  
Vol 29 (2) ◽  
pp. 409-415 ◽  
Author(s):  
Xuexiang Wang ◽  
Ranadheer R. Dande ◽  
Hao Yu ◽  
Beata Samelko ◽  
Rachel E. Miller ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Calcium Influx ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Transgenic Mouse Models ◽  
Cytoskeletal Remodeling ◽  
Englerin A ◽  
Transient Receptor ◽  
Ion Pore

Transient receptor potential channel 5 (TRPC5) is highly expressed in brain and kidney and mediates calcium influx and promotes cell migration. In the kidney, loss of TRPC5 function has been reported to benefit kidney filter dynamics by balancing podocyte cytoskeletal remodeling. However, in vivo gain-in-function studies of TRPC5 with respect to kidney function have not been reported. To address this gap, we developed two transgenic mouse models on the C57BL/6 background by overexpressing either wild-type TRPC5 or a TRPC5 ion-pore mutant. Compared with nontransgenic controls, neither transgenic model exhibited an increase in proteinuria at 8 months of age or a difference in LPS-induced albuminuria. Moreover, activation of TRPC5 by Englerin A did not stimulate proteinuria, and inhibition of TRPC5 by ML204 did not significantly lower the level of LPS-induced proteinuria in any group. Collectively, these data suggest that the overexpression or activation of the TRPC5 ion channel does not cause kidney barrier injury or aggravate such injury under pathologic conditions.

scholarly journals Structure of the ancestral TRPY1 channel from Saccharomyces cerevisiae reveals mechanisms of modulation by lipids and calcium

2020 ◽  
Author(s):  
Tofayel Ahmed ◽  
Collin R. Nisler ◽  
Edwin C. Fluck ◽  
Marcos Sotomayor ◽  
Vera Y. Moiseenkova-Bell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transient Receptor Potential ◽  
Transmembrane Domain ◽  
Trp Channels ◽  
Receptor Potential ◽  
Lipid Binding ◽  
Channel Modulation ◽  
Channel Inhibition ◽  
Transient Receptor ◽  
Dynamics Simulations

ABSTRACTTransient Receptor Potential (TRP) channels have evolved in eukaryotes to control various cellular functions in response to a wide variety of chemical and physical stimuli. This large and diverse family of channels emerged in fungi as mechanosensitive osmoregulators. The Saccharomyces cerevisiae vacuolar TRP yeast 1 (TRPY1) is the most studied TRP channel from fungi, but the molecular details of channel modulation remain elusive so far. Here, we describe the full-length cryo-electron microscopy structure of TRPY1 at 3.1 Å resolution. The structure reveals a distinctive architecture for TRPY1 among all eukaryotic TRP channels with an evolutionarily conserved and archetypical transmembrane domain, but distinct structural folds for the cytosolic N- and C-termini. We identified the inhibitory phosphatidylinositol 3-phosphate (PI(3)P) lipid binding site, which sheds light into the lipid modulation of TRPY1 in the vacuolar membrane. The structure also exhibited two Ca2+-binding sites: one in the cytosolic side, implicated in channel activation, and the other in the vacuolar lumen side, involved in channel inhibition. These findings, together with data from molecular dynamics simulations, provide structural insights into the basis of TRPY1 channel modulation by lipids and Ca2+.

scholarly journals Structure–function analyses of the ion channel TRPC3 reveal that its cytoplasmic domain allosterically modulates channel gating

2018 ◽  
Vol 293 (41) ◽  
pp. 16102-16114 ◽  
Author(s):  
Francisco Sierra-Valdez ◽  
Caleigh M. Azumaya ◽  
Luis O. Romero ◽  
Terunaga Nakagawa ◽  
Julio F. Cordero-Morales
Keyword(s):  
Conformational Changes ◽  
Transient Receptor Potential ◽  
Transmembrane Domain ◽  
Trp Channels ◽  
Channel Gating ◽  
Memory Loss ◽  
Receptor Potential ◽  
Cytoplasmic Domain ◽  
Terminal Loop ◽  
Transient Receptor

The transient receptor potential ion channels support Ca2+ permeation in many organs, including the heart, brain, and kidney. Genetic mutations in transient receptor potential cation channel subfamily C member 3 (TRPC3) are associated with neurodegenerative diseases, memory loss, and hypertension. To better understand the conformational changes that regulate TRPC3 function, we solved the cryo-EM structures for the full-length human TRPC3 and its cytoplasmic domain (CPD) in the apo state at 5.8- and 4.0-Å resolution, respectively. These structures revealed that the TRPC3 transmembrane domain resembles those of other TRP channels and that the CPD is a stable module involved in channel assembly and gating. We observed the presence of a C-terminal domain swap at the center of the CPD where horizontal helices (HHs) transition into a coiled-coil bundle. Comparison of TRPC3 structures revealed that the HHs can reside in two distinct positions. Electrophysiological analyses disclosed that shortening the length of the C-terminal loop connecting the HH with the TRP helices increases TRPC3 activity and that elongating the length of the loop has the opposite effect. Our findings indicate that the C-terminal loop affects channel gating by altering the allosteric coupling between the cytoplasmic and transmembrane domains. We propose that molecules that target the HH may represent a promising strategy for controlling TRPC3-associated neurological disorders and hypertension.

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