Direct Interaction with Rab11a Targets the Epithelial Ca2+ Channels TRPV5 and TRPV6 to the Plasma Membrane

ABSTRACT TRPV5 and TRPV6 are the most Ca2+-selective members of the transient receptor potential (TRP) family of cation channels and play a pivotal role in the maintenance of Ca2+ balance in the body. However, little is known about the mechanisms controlling the plasma membrane abundance of these channels to regulate epithelial Ca2+ transport. In this study, we demonstrated the direct and specific interaction of GDP-bound Rab11a with TRPV5 and TRPV6. Rab11a colocalized with TRPV5 and TRPV6 in vesicular structures underlying the apical plasma membrane of Ca2+-transporting epithelial cells. This GTPase recognized a conserved stretch in the carboxyl terminus of TRPV5 that is essential for channel trafficking. Furthermore, coexpression of GDP-locked Rab11a with TRPV5 or TRPV6 resulted in significantly decreased Ca2+ uptake, caused by diminished channel cell surface expression. Together, our data demonstrated the important role of Rab11a in the trafficking of TRPV5 and TRPV6. Rab11a exerts this function in a novel fashion, since it operates via direct cargo interaction while in the GDP-bound configuration.

Download Full-text

Counteracting effect of TRPC1-associated Ca2+influx on TNF-α-induced COX-2-dependent prostaglandin E2production in human colonic myofibroblasts

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00354.2010 ◽

2011 ◽

Vol 301 (2) ◽

pp. G356-G367 ◽

Cited By ~ 20

Author(s):

Lin Hai ◽

Yasuhiro Kawarabayashi ◽

Yuko Imai ◽

Akira Honda ◽

Ryuji Inoue

Keyword(s):

Transient Receptor Potential ◽

Nuclear Translocation ◽

Receptor Potential ◽

Selective Inhibition ◽

Surface Expression ◽

Cell Surface Expression ◽

Prostaglandin E ◽

Tnf Α ◽

Cox 2 ◽

Transient Receptor

TNF-α-NF-κB signaling plays a central role in inflammation, apoptosis, and neoplasia. One major consequence of this signaling in the gut is increased production of prostaglandin E2(PGE2) via cyclooxygenase-2 (COX-2) induction in myofibroblasts, which has been reported to be dependent on Ca2+. In this study, we explored a potential role of canonical transient receptor potential (TRPC) proteins in this Ca2+-mediated signaling using a human colonic myofibroblast cell line CCD-18Co. In CCD-18Co cell, treatment with TNF-α greatly enhanced Ca2+influx induced by store depletion along with increased cell-surface expression of TRPC1 protein (but not of the other TRPC isoforms) and induction of a Gd3+-sensitive nonselective cationic conductance. Selective inhibition of TRPC1 expression by small interfering RNA (siRNA) or functionally effective TRPC1 antibody targeting the near-pore region of TRPC1 (T1E3) antagonized the enhancement of store-dependent Ca2+influx by TNF-α, whereas potentiated TNF-α induced PGE2production. Overexpression of TRPC1 in CCD-18Co produced opposite consequences. Inhibitors of NF-κB (curcumin, SN-50) attenuated TNF-α-induced enhancement of TRPC1 expression, store-dependent Ca2+influx, and COX-2-dependent PGE2production. In contrast, inhibition of calcineurin-nuclear factor of activated T-cell proteins (NFAT) signaling by FK506 or NFAT Activation Inhibitor III enhanced the PGE2production without affecting TRPC1 expression and the Ca2+influx. Finally, the suppression of store-dependent Ca2+influx by T1E3 antibody or siRNA knockdown significantly facilitated TNF-α-induced NF-κB nuclear translocation. In aggregate, these results strongly suggest that, in colonic myofibroblasts, NF-κB and NFAT serve as important positive and negative transcriptional regulators of TNF-α-induced COX-2-dependent PGE2production, respectively, at the downstream of TRPC1-associated Ca2+influx.

Download Full-text

Inositol lipids and TRPC channel activation

Biochemical Society Symposium ◽

10.1042/bss2007c04 ◽

2007 ◽

Vol 74 ◽

pp. 37-45 ◽

Cited By ~ 12

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.

Download Full-text

The transient receptor potential, TRP4, cation channel is a novel member of the family of calmodulin binding proteins

Biochemical Journal ◽

10.1042/bj3550663 ◽

2001 ◽

Vol 355 (3) ◽

pp. 663-670 ◽

Cited By ~ 62

Author(s):

Claudia TROST ◽

Christiane BERGS ◽

Nina HIMMERKUS ◽

Veit FLOCKERZI

Keyword(s):

Amino Acid ◽

Ion Channels ◽

Transient Receptor Potential ◽

Direct Interaction ◽

Receptor Potential ◽

Amino Acid Residues ◽

Glutathione S Transferase ◽

Calmodulin Binding ◽

Transient Receptor

The mammalian gene products, transient receptor potential (trp)1 to trp7, are related to the Drosophila TRP and TRP-like ion channels, and are candidate proteins underlying agonist-activated Ca2+-permeable ion channels. Recently, the TRP4 protein has been shown to be part of native store-operated Ca2+-permeable channels. These channels, most likely, are composed of other proteins in addition to TRP4. In the present paper we report the direct interaction of TRP4 and calmodulin (CaM) by: (1) retention of in vitro translated TRP4 and of TRP4 protein solubilized from bovine adrenal cortex by CaM–Sepharose in the presence of Ca2+, and (2) TRP4–glutathione S-transferase pull-down experiments. Two domains of TRP4, amino acid residues 688–759 and 786–848, were identified as being able to interact with CaM. The binding of CaM to both domains occurred only in the presence of Ca2+ concentrations above 10µM, with half maximal binding occurring at 16.6µM (domain 1) and 27.9µM Ca2+ (domain 2). Synthetic peptides, encompassing the two putative CaM binding sites within these domains and covering amino acid residues 694–728 and 829–853, interacted directly with dansyl–CaM with apparent Kd values of 94–189nM. These results indicate that TRP4/Ca2+-CaM are parts of a signalling complex involved in agonist-induced Ca2+ entry.

Download Full-text

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

Biochemical Journal ◽

10.1042/bj3640245 ◽

2002 ◽

Vol 364 (1) ◽

pp. 245-254 ◽

Cited By ~ 60

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.

Download Full-text

Functional Interaction among KCa and TRP Channels for Cardiovascular Physiology: Modern Perspectives on Aging and Chronic Disease

International Journal of Molecular Sciences ◽

10.3390/ijms20061380 ◽

2019 ◽

Vol 20 (6) ◽

pp. 1380 ◽

Cited By ~ 6

Author(s):

Erik Behringer ◽

Md Hakim

Keyword(s):

Blood Flow ◽

Transient Receptor Potential ◽

Trp Channels ◽

Receptor Potential ◽

The Body ◽

Cardiovascular Physiology ◽

Treatment And Prevention ◽

Kca Channels ◽

Age Related ◽

Transient Receptor

Effective delivery of oxygen and essential nutrients to vital organs and tissues throughout the body requires adequate blood flow supplied through resistance vessels. The intimate relationship between intracellular calcium ([Ca2+]i) and regulation of membrane potential (Vm) is indispensable for maintaining blood flow regulation. In particular, Ca2+-activated K+ (KCa) channels were ascertained as transducers of elevated [Ca2+]i signals into hyperpolarization of Vm as a pathway for decreasing vascular resistance, thereby enhancing blood flow. Recent evidence also supports the reverse role for KCa channels, in which they facilitate Ca2+ influx into the cell interior through open non-selective cation (e.g., transient receptor potential; TRP) channels in accord with robust electrical (hyperpolarization) and concentration (~20,000-fold) transmembrane gradients for Ca2+. Such an arrangement supports a feed-forward activation of Vm hyperpolarization while potentially boosting production of nitric oxide. Furthermore, in vascular types expressing TRP channels but deficient in functional KCa channels (e.g., collecting lymphatic endothelium), there are profound alterations such as downstream depolarizing ionic fluxes and the absence of dynamic hyperpolarizing events. Altogether, this review is a refined set of evidence-based perspectives focused on the role of the endothelial KCa and TRP channels throughout multiple experimental animal models and vascular types. We discuss the diverse interactions among KCa and TRP channels to integrate Ca2+, oxidative, and electrical signaling in the context of cardiovascular physiology and pathology. Building from a foundation of cellular biophysical data throughout a wide and diverse compilation of significant discoveries, a translational narrative is provided for readers toward the treatment and prevention of chronic, age-related cardiovascular disease.

Download Full-text

TRP and the PDZ Protein, Inad, Form the Core Complex Required for Retention of the Signalplex in Drosophila Photoreceptor Cells

The Journal of Cell Biology ◽

10.1083/jcb.150.6.1411 ◽

2000 ◽

Vol 150 (6) ◽

pp. 1411-1422 ◽

Cited By ~ 126

Author(s):

Hong-Sheng Li ◽

Craig Montell

Keyword(s):

Transient Receptor Potential ◽

Direct Interaction ◽

Light Response ◽

Receptor Potential ◽

Photoreceptor Cells ◽

Macromolecular Complex ◽

Pdz Domains ◽

The Core ◽

Transient Receptor ◽

Drosophila Photoreceptor

The light response in Drosophila photoreceptor cells is mediated by a series of proteins that assemble into a macromolecular complex referred to as the signalplex. The central player in the signalplex is inactivation no afterpotential D (INAD), a protein consisting of a tandem array of five PDZ domains. At least seven proteins bind INAD, including the transient receptor potential (TRP) channel, which depends on INAD for localization to the phototransducing organelle, the rhabdomere. However, the determinants required for localization of INAD are not known. In this work, we showed that INAD was required for retention rather than targeting of TRP to the rhabdomeres. In addition, we demonstrated that TRP bound to INAD through the COOH terminus, and this interaction was required for localization of INAD. Other proteins that depend on INAD for localization, phospholipase C and protein kinase C, also mislocalized. However, elimination of any other member of the signalplex had no impact on the spatial distribution of INAD. A direct interaction between TRP and INAD did not appear to have a role in the photoresponse independent of localization of multiple signaling components. Rather, the primary function of the TRP/ INAD complex is to form the core unit required for localization of the signalplex to the rhabdomeres.

Download Full-text

TRP Channels as Sensors of Aldehyde and Oxidative Stress

Biomolecules ◽

10.3390/biom11101401 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1401

Author(s):

Katharina E. M. Hellenthal ◽

Laura Brabenec ◽

Eric R. Gross ◽

Nana-Maria Wagner

Keyword(s):

Lipid Peroxidation ◽

Transient Receptor Potential ◽

Trp Channels ◽

Treatment Options ◽

Receptor Potential ◽

The Body ◽

Trp Channel ◽

Alcoholic Beverages ◽

Organ Injury ◽

Transient Receptor

The transient receptor potential (TRP) cation channel superfamily comprises more than 50 channels that play crucial roles in physiological processes. TRP channels are responsive to several exogenous and endogenous biomolecules, with aldehydes emerging as a TRP channel trigger contributing to a cellular cascade that can lead to disease pathophysiology. The body is not only exposed to exogenous aldehydes via tobacco products or alcoholic beverages, but also to endogenous aldehydes triggered by lipid peroxidation. In response to lipid peroxidation from inflammation or organ injury, polyunsaturated fatty acids undergo lipid peroxidation to aldehydes, such as 4-hydroxynonenal. Reactive aldehydes activate TRP channels via aldehyde-induced protein adducts, leading to the release of pro-inflammatory mediators driving the pathophysiology caused by cellular injury, including inflammatory pain and organ reperfusion injury. Recent studies have outlined how aldehyde dehydrogenase 2 protects against aldehyde toxicity through the clearance of toxic aldehydes, indicating that targeting the endogenous aldehyde metabolism may represent a novel treatment strategy. An addition approach can involve targeting specific TRP channel regions to limit the triggering of a cellular cascade induced by aldehydes. In this review, we provide a comprehensive summary of aldehydes, TRP channels, and their interactions, as well as their role in pathological conditions and the different therapeutical treatment options.

Download Full-text

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

Frontiers in Pharmacology ◽

10.3389/fphar.2020.593319 ◽

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.

Download Full-text

Functional characterization of transient receptor potential channels in mouse urothelial cells

AJP Renal Physiology ◽

10.1152/ajprenal.00599.2009 ◽

2010 ◽

Vol 298 (3) ◽

pp. F692-F701 ◽

Cited By ~ 101

Author(s):

Wouter Everaerts ◽

Joris Vriens ◽

Grzegorz Owsianik ◽

Giovanni Appendino ◽

Thomas Voets ◽

...

Keyword(s):

Plasma Membrane ◽

Patch Clamp ◽

Calcium Imaging ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Functional Expression ◽

Sensory Function ◽

Trp Channel ◽

Urothelial Cells ◽

Transient Receptor

The bladder urothelium is currently believed to be a sensory structure, contributing to mechano- and chemosensation in the bladder. Transient receptor potential (TRP) cation channels act as polymodal sensors and may underlie some of the receptive properties of urothelial cells. However, the exact TRP channel expression profile of urothelial cells is unclear. In this study, we have performed a systematic analysis of the molecular and functional expression of various TRP channels in mouse urothelium. Urothelial cells from control and trpv4−/− mice were isolated, cultured (12–48 h), and used for quantitative real-time PCR, immunocytochemistry, calcium imaging, and whole cell patch-clamp experiments. At the mRNA level, TRPV4, TRPV2, and TRPM7 were the most abundantly expressed TRP genes. Immunohistochemistry showed a clear expression of TRPV4 in the plasma membrane, whereas TRPV2 was more prominent in the cytoplasm. TRPM7 was detected in the plasma membrane as well as cytoplasmic vesicles. Calcium imaging and patch-clamp experiments using TRP channel agonists and antagonists provided evidence for the functional expression of TRPV4, TRPV2, and TRPM7 but not of TRPA1, TRPV1, and TRPM8. In conclusion, we have demonstrated functional expression of TRPV4, TRPV2, and TRPM7 in mouse urothelial cells. These channels may contribute to the (mechano)sensory function of the urothelial layer and represent potential targets for the treatment of bladder dysfunction.

Download Full-text