TRPC1: a core component of store-operated calcium channels

2007 ◽  
Vol 35 (1) ◽  
pp. 96-100 ◽  
Author(s):  
I.S. Ambudkar
Keyword(s):  
Calcium Release ◽  
Transient Receptor Potential ◽  
Calcium Signalling ◽  
Receptor Potential ◽  
Cell Types ◽  
Surface Expression ◽  
Membrane Microdomains ◽  
Store Operated Calcium Entry ◽  
Transient Receptor ◽  
And Function

The TRPC (transient receptor potential canonical) proteins are activated in response to agonist-stimulated PIP2 (phosphatidylinositol 4,5-bisphosphate) hydrolysis and have been suggested as candidate components of the elusive SOC (store-operated calcium channel). TRPC1 is currently the strongest candidate component of SOC. Endogenous TRPC1 has been shown to contribute to SOCE (store-operated calcium entry) in several different cell types. However, the mechanisms involved in the regulation of TRPC1 and its exact physiological function have yet to be established. Studies from our laboratory and several others have demonstrated that TRPC1 is assembled in a signalling complex with key calcium signalling proteins in functionally specific plasma membrane microdomains. Furthermore, critical interactions between TRPC1 monomers as well as interactions between TRPC1 and other proteins determine the surface expression and function of TRPC1-containing channels. Recent studies have revealed novel regulators of TRPC1-containing SOCs and have demonstrated a common molecular basis for the regulation of CRAC (calcium-release-activated calcium) and SOC channels. In the present paper, we will revisit the role of TRPC1 in SOCE and discuss how studies with TRPC1 provide an experimental basis for validating the mechanism of SOCE.

scholarly journals Nanomolar ouabain increases NCX1 expression and enhances Ca2+ signaling in human arterial myocytes: a mechanism that links salt to increased vascular resistance?

2012 ◽  
Vol 303 (7) ◽  
pp. H784-H794 ◽  
Author(s):  
Cristina I. Linde ◽  
Laura K. Antos ◽  
Vera A. Golovina ◽  
Mordecai P. Blaustein
Keyword(s):  
Vascular Resistance ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Whole Body ◽  
Membrane Microdomains ◽  
Α Subunit ◽  
Plasmic Reticulum ◽  
Endogenous Ouabain ◽  
Transient Receptor ◽  
And Function

The mechanisms by which NaCl raises blood pressure (BP) in hypertension are unresolved, but much evidence indicates that endogenous ouabain is involved. In rodents, arterial smooth muscle cell (ASMC) Na+ pumps with an α2-catalytic subunit (ouabain EC50 ≤1.0 nM) are crucial for some hypertension models, even though ≈80% of ASMC Na+ pumps have an α1-subunit (ouabain EC50 ≈ 5 μM). Human α1-Na+ pumps, however, have high ouabain affinity (EC50 ≈ 10–20 nM). We used immunoblotting, immunocytochemistry, and Ca2+ imaging (fura-2) to examine the expression, distribution, and function of Na+ pump α-subunit isoforms in human arteries and primary cultured human ASMCs (hASMCs). hASMCs express α1- and α2-Na+ pumps. Further, α2-, but not α1-, pumps are confined to plasma membrane microdomains adjacent to sarcoplasmic reticulum (SR), where they colocalize with Na/Ca exchanger-1 (NCX1) and C-type transient receptor potential-6 (receptor-operated channels, ROCs). Prolonged inhibition (72 h) with 100 nM ouabain (blocks nearly all α1- and α2-pumps) was toxic to most cultured hASMCs. Treatment with 10 nM ouabain (72 h), however, increased NCX1 and sarco(endo)plasmic reticulum Ca2+-ATPase expression and augmented ATP (10 μM)-induced SR Ca2+ release in 0 Ca2+, ouabain-free media, and Ca2+ influx after external Ca2+ restoration. The latter was likely mediated primarily by ROCs and store-operated Ca2+ channels. These hASMC protein expression and Ca2+ signaling changes are comparable with previous observations on myocytes isolated from arteries of many rat hypertension models. We conclude that the same structurally and functionally coupled mechanisms (α2-Na+ pumps, NCX1, ROCs, and the SR) regulate Ca2+ homeostasis and signaling in hASMCs and rodent ASMCs. These ouabain/endogenous ouabain-modulated mechanisms underlie the whole body autoregulation associated with increased vascular resistance and elevation of BP in human, salt-sensitive hypertension.

Regulation of calcium signalling by adenine-based second messengers

2007 ◽  
Vol 35 (1) ◽  
pp. 109-114 ◽  
Author(s):  
R. Fliegert ◽  
A. Gasser ◽  
A.H. Guse
Keyword(s):  
Transient Receptor Potential ◽  
Second Messengers ◽  
Calcium Signalling ◽  
Receptor Potential ◽  
Cell Types ◽  
Cellular Systems ◽  
Membrane Receptors ◽  
Transient Receptor Potential Melastatin ◽  
Transient Receptor ◽  
Plasma Membrane Receptors

cADPR [cyclic ADPR (ADP-ribose)], NAADP (nicotinic acid–adenine dinucleotide phosphate) and ADPR belong to the family of adenine-containing second messengers. They are metabolically related and are all involved in the regulation of cellular Ca2+ homoeostasis. Activation of specific plasma membrane receptors is connected to cADPR formation in many cell types and tissues. In contrast receptor-mediated formation of NAADP and ADPR has been shown only in a few selected cellular systems. The intracellular Ca2+ channel triggered by cADPR is the RyR (ryanodine receptor); in the case of NAADP, both activation of RyR and a novel Ca2+ channel have been proposed. In contrast, ADPR opens the non-specific cation channel TRPM2 [TRP (transient receptor potential) melastatin 2] that belongs to the TRP family of ion channels.

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.

TRPC1, TRPC3, and TRPC4 in Rat Orofacial Structures

2017 ◽  
Vol 204 (5-6) ◽  
pp. 293-303 ◽  
Author(s):  
Masatoshi Fujita ◽  
Tadasu Sato ◽  
Takehiro Yajima ◽  
Eiji Masaki ◽  
Hiroyuki Ichikawa
Keyword(s):  
Transient Receptor Potential ◽  
Sympathetic Neurons ◽  
Receptor Potential ◽  
Monovalent Cation ◽  
Calcitonin Gene ◽  
Cervical Ganglion ◽  
Parasympathetic Neurons ◽  
Transient Receptor ◽  
And Function ◽  
And Control

TRPC (transient receptor potential cation channel subfamily C) members are nonselective monovalent cation channels and control Ca2+ inflow. In this study, immunohistochemistry for TRPC1, TRPC3, and TRPC4 was performed on rat oral and craniofacial structures to elucidate their distribution and function in the peripheries. In the trigeminal ganglion (TG), 56.1, 84.1, and 68.3% of sensory neurons were immunoreactive (IR) for TRPC1, TRPC3, and TRPC4, respectively. A double immunofluorescence method revealed that small to medium-sized TG neurons co-expressed TRPCs and calcitonin gene-related peptide. In the superior cervical ganglion, all sympathetic neurons showed TRPC1 and TRPC3 immunoreactivity. Parasympathetic neurons in the submandibular ganglion, tongue, and parotid gland were TRPC1, TRPC3, and TRPC4 IR. Gustatory and olfactory cells were also IR for TRPC1, TRPC3, and/or TRPC4. In the musculature, motor endplates expressed TRPC1 and TRPC4 immunoreactivity. It is likely that TRPCs are associated with sensory, autonomic, and motor functions in oral and craniofacial structures.

DISTRIBUTION AND FUNCTION OF TRANSIENT RECEPTOR POTENTIAL ION CHANNEL A1 (TRPA1) AND CANNABINOID RECEPTORS IN THE HUMAN PROSTATE

2009 ◽  
Vol 181 (4S) ◽  
pp. 506-506
Author(s):  
Christian Gratzke ◽  
Philipp Weinhold ◽  
Oliver Reich ◽  
Christian G Stief ◽  
Karl-Erik Andersson ◽  
...  
Keyword(s):  
Ion Channel ◽  
Cannabinoid Receptors ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Human Prostate ◽  
Transient Receptor ◽  
And Function

scholarly journals Analgesic Effects of Lipid Raft Disruption by Sphingomyelinase and Myriocin via Transient Receptor Potential Vanilloid 1 and Transient Receptor Potential Ankyrin 1 Ion Channel Modulation

2021 ◽  
Vol 11 ◽  
Author(s):  
Ádám Horváth ◽  
Maja Payrits ◽  
Anita Steib ◽  
Boglárka Kántás ◽  
Tünde Biró-Süt ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Lipid Raft ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Membrane Microdomains ◽  
Neuronal Cultures ◽  
Transient Receptor Potential Vanilloid ◽  
Peripheral Sensitization ◽  
Transient Receptor

Transient Receptor Potential (TRP) Vanilloid 1 and Ankyrin 1 (TRPV1, TRPA1) cation channels are expressed in nociceptive primary sensory neurons, and integratively regulate nociceptor and inflammatory functions. Lipid rafts are liquid-ordered plasma membrane microdomains rich in cholesterol, sphingomyelin and gangliosides. We earlier showed that lipid raft disruption inhibits TRPV1 and TRPA1 functions in primary sensory neuronal cultures. Here we investigated the effects of sphingomyelinase (SMase) cleaving membrane sphingomyelin and myriocin (Myr) prohibiting sphingolipid synthesis in mouse pain models of different mechanisms. SMase (50 mU) or Myr (1 mM) pretreatment significantly decreased TRPV1 activation (capsaicin)-induced nocifensive eye-wiping movements by 37 and 41%, respectively. Intraplantar pretreatment by both compounds significantly diminished TRPV1 stimulation (resiniferatoxin)-evoked thermal allodynia developing mainly by peripheral sensitization. SMase (50 mU) also decreased mechanical hyperalgesia related to both peripheral and central sensitizations. SMase (50 mU) significantly reduced TRPA1 activation (formalin)-induced acute nocifensive behaviors by 64% in the second, neurogenic inflammatory phase. Myr, but not SMase altered the plasma membrane polarity related to the cholesterol composition as shown by fluorescence spectroscopy. These are the first in vivo results showing that sphingolipids play a key role in lipid raft integrity around nociceptive TRP channels, their activation and pain sensation. It is concluded that local SMase administration might open novel perspective for analgesic therapy.

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