1
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Wilk LS, Doppegieter M, van der Beek N, van Leeuwen TG, Aalders MCG. Modeling pulsed dye laser treatment of psoriatic plaques by combining numerical methods and image-derived lesion morphologies. Lasers Surg Med 2024; 56:508-522. [PMID: 38576388 DOI: 10.1002/lsm.23781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/27/2024] [Accepted: 03/20/2024] [Indexed: 04/06/2024]
Abstract
OBJECTIVES Knowledge of the physical effects of pulsed dye laser (PDL) treatment of psoriatic lesions is essential in unraveling the remedial mechanisms of this treatment and hence also in maximizing in its disease-modifying potential. Therefore, the main objective of this study was to provide estimates of these physical effects (for laser wavelengths of 585 and 595 nm), with the aim of identifying pathogenic processes that may be affected by these conditions. METHODS We modeled the laser light propagation and subsequent photothermal heating by numerically solving the transient diffusion and heat equations simultaneously. To this end, we used the finite element method in conjunction with an image-derived psoriatic lesion morphology (which was defined by segmenting blood vessels from a confocal microscopy image of a fluorescently labeled section of a 3 mm punch biopsy of a psoriatic lesion). The resulting predictions of the generated temperature field within the lesion were then used to assess the possibility of stalling or arresting some suspected pathogenic processes. RESULTS According to our results, it is conceivable that perivascular nerves are thermally denatured, as almost all locations that reach 60°C were found to be within 18 µm (at 585 nm) and 11 µm (at 595 nm) of a blood vessel wall. Furthermore, activation of TRPV1 and TRPV2 channels in perivascular neuronal and immune cells is highly likely, since a critical temperature of 43°C is generated at locations within up to 350 µm of a vessel wall (at both wavelengths) and sustained for up to 700 ms (at 585 nm) and 40 ms (at 595 nm), while a critical temperature of 52°C is reached by locations within 80 µm (at 585 nm) and 30 µm (at 595 nm) of a vessel wall and sustained for up to 100 ms (at 585 nm) and 30 ms (at 595 nm). Finally, we found that the blood vessel coagulation-inducing temperature of 70°C is sustained in the vascular epithelium for up to 19 and 5 ms at 585 and 595 nm, respectively, rendering partial or total loss of vascular functionality a distinct possibility. CONCLUSIONS The presented approach constitutes a useful tool to provide realistic estimates of the photothermal effects of PDL treatment of psoriatic plaques (as well as other selective photothermolysis-based treatments), yielding information that is essential in guiding future experimental studies toward unraveling the remedial mechanisms of these treatments.
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Affiliation(s)
- Leah S Wilk
- Amsterdam UMC, location University of Amsterdam, Biomedical Engineering and Physics, Amsterdam, The Netherlands
- Co van Ledden Hulsebosch Center, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Public Health, Methodology, Amsterdam, The Netherlands
| | - Meagan Doppegieter
- Amsterdam UMC, location University of Amsterdam, Biomedical Engineering and Physics, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Microcirculation, Amsterdam, The Netherlands
| | - Nick van der Beek
- ZBC MultiCare, Independent Treatment Center for Dermatology, Hilversum, The Netherlands
| | - Ton G van Leeuwen
- Amsterdam UMC, location University of Amsterdam, Biomedical Engineering and Physics, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure and Arrythmias, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
| | - Maurice C G Aalders
- Amsterdam UMC, location University of Amsterdam, Biomedical Engineering and Physics, Amsterdam, The Netherlands
- Co van Ledden Hulsebosch Center, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Public Health, Methodology, Amsterdam, The Netherlands
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2
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Wang G. Thermo-ring basis for heat unfolding-induced inactivation in TRPV1. RESEARCH SQUARE 2024:rs.3.rs-3280283. [PMID: 37674717 PMCID: PMC10479453 DOI: 10.21203/rs.3.rs-3280283/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Transient receptor potential vanilloid-1 (TRPV1) is a capsaicin receptor and employs the use-dependent desensitization to protect mammals from noxious heat damage in response to repeated or constant heat stimuli. However, the underlying structural factor or motif has not been resolved precisely. In this computational study, the graph theory-based grid thermodynamic model was used to reveal how the temperature-dependent noncovalent interactions as identified in the 3D structures of rat TRPV1 could develop a well-organized fluidic grid-like mesh network, featuring various topological grids constrained as the thermo-rings that range in size from the biggest to the smallest to govern distinct structural and functional traits of the channel in response to varying temperature degrees. Following the findings that the heat unfolding of three specific biggest grids, one in the closed state and two in the open state, was respectively responsible for the reversible activation at 43 °C and thermal inactivation from 56 °C to 61 °C, a random smaller grid was further identified for the irreversible inactivation and the relevant use-dependent desensitization from the pre-open closed state between 43 °C and 61 °C. Thus, these two distinct inactivation pathways of TRPV1 may be involved in protecting mammals against noxious heat damages.
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Affiliation(s)
- Guangyu Wang
- Department of Physiology and Membrane Biology, University of California School of Medicine, Davis, CA 95616, USA
- Department of Drug Research and Development, Institute of Biophysical Medico-chemistry, Reno, NV 89523, USA
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3
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Maximiano TKE, Carneiro JA, Fattori V, Verri WA. TRPV1: Receptor structure, activation, modulation and role in neuro-immune interactions and pain. Cell Calcium 2024; 119:102870. [PMID: 38531262 DOI: 10.1016/j.ceca.2024.102870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 03/06/2024] [Accepted: 03/06/2024] [Indexed: 03/28/2024]
Abstract
In the 1990s, the identification of a non-selective ion channel, especially responsive to capsaicin, revolutionized the studies of somatosensation and pain that were to follow. The TRPV1 channel is expressed mainly in neuronal cells, more specifically, in sensory neurons responsible for the perception of noxious stimuli. However, its presence has also been detected in other non-neuronal cells, such as immune cells, β- pancreatic cells, muscle cells and adipocytes. Activation of the channel occurs in response to a wide range of stimuli, such as noxious heat, low pH, gasses, toxins, endocannabinoids, lipid-derived endovanilloid, and chemical agents, such as capsaicin and resiniferatoxin. This activation results in an influx of cations through the channel pore, especially calcium. Intracellular calcium triggers different responses in sensory neurons. Dephosphorylation of the TRPV1 channel leads to its desensitization, which disrupts its function, while its phosphorylation increases the channel's sensitization and contributes to the channel's rehabilitation after desensitization. Kinases, phosphoinositides, and calmodulin are the main signaling pathways responsible for the channel's regulation. Thus, in this review we provide an overview of TRPV1 discovery, its tissue expression as well as on the mechanisms by which TRPV1 activation (directly or indirectly) induces pain in different disease models.
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Affiliation(s)
- Thaila Kawane Euflazio Maximiano
- Laboratory of Pain, Inflammation, Neuropathy, and Cancer, Department of Pathology, Center of Biological Sciences, Londrina State University, Londrina, Paraná, Brazil
| | - Jessica Aparecida Carneiro
- Laboratory of Pain, Inflammation, Neuropathy, and Cancer, Department of Pathology, Center of Biological Sciences, Londrina State University, Londrina, Paraná, Brazil
| | - Victor Fattori
- Vascular Biology Program, Department of Surgery, Boston Children's Hospital-Harvard Medical School, Karp Research Building, 300 Longwood Ave, 02115, Boston, Massachusetts, United States.
| | - Waldiceu A Verri
- Laboratory of Pain, Inflammation, Neuropathy, and Cancer, Department of Pathology, Center of Biological Sciences, Londrina State University, Londrina, Paraná, Brazil.
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4
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York JM. Temperature activated transient receptor potential ion channels from Antarctic fishes. Open Biol 2023; 13:230215. [PMID: 37848053 PMCID: PMC10581778 DOI: 10.1098/rsob.230215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/01/2023] [Indexed: 10/19/2023] Open
Abstract
Antarctic notothenioid fishes (cryonotothenioids) live in waters that range between -1.86°C and an extreme maximum +4°C. Evidence suggests these fish sense temperature peripherally, but the molecular mechanism of temperature sensation in unknown. Previous work identified transient receptor potential (TRP) channels TRPA1b, TRPM4 and TRPV1a as the top candidates for temperature sensors. Here, cryonotothenioid TRPA1b and TRPV1a are characterized using Xenopus oocyte electrophysiology. TRPA1b and TRPV1a showed heat-evoked currents with Q10s of 11.1 ± 2.2 and 20.5 ± 2.4, respectively. Unexpectedly, heat activation occurred at a threshold of 22.9 ± 1.3°C for TRPA1b and 32.1 ± 0.6°C for TRPV1a. These fish have not experienced such temperatures for at least 15 Myr. Either (1) another molecular mechanism underlies temperature sensation, (2) these fishes do not sense temperatures below these thresholds despite having lethal limits as low as 5°C, or (3) native cellular conditions modify the TRP channels to function at relevant temperatures. The effects of osmolytes, pH, oxidation, phosphorylation, lipids and accessory proteins were tested. No conditions shifted the activity range of TRPV1a. Oxidation in combination with reduced cholesterol significantly dropped activation threshold of TRPA1b to 11.3 ± 2.3°C, it is hypothesized the effect may be due to lipid raft disruption.
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Affiliation(s)
- Julia M. York
- Department of Integrative Biology, Institute for Neuroscience, University of Texas at Austin, Austin, TX, USA
- School of Integrative Biology, University of Illinois Urbana–Champaign, Urbana, Illinois, USA
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5
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Mugo A, Chou R, Chin F, Liu B, Jiang QX, Qin F. A suicidal mechanism for the exquisite temperature sensitivity of TRPV1. Proc Natl Acad Sci U S A 2023; 120:e2300305120. [PMID: 37639609 PMCID: PMC10483596 DOI: 10.1073/pnas.2300305120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 07/21/2023] [Indexed: 08/31/2023] Open
Abstract
The vanilloid receptor TRPV1 is an exquisite nociceptive sensor of noxious heat, but its temperature-sensing mechanism is yet to define. Thermodynamics dictate that this channel must undergo an unusually energetic allosteric transition. Thus, it is of fundamental importance to measure directly the energetics of this transition in order to properly decipher its temperature-sensing mechanism. Previously, using submillisecond temperature jumps and patch-clamp recording, we estimated that the heat activation for TRPV1 opening incurs an enthalpy change on the order of 100 kcal/mol. Although this energy is on a scale unparalleled by other known biological receptors, the generally imperfect allosteric coupling in proteins implies that the actual amount of heat uptake driving the TRPV1 transition could be much larger. In this paper, we apply differential scanning calorimetry to directly monitor the heat flow in TRPV1 that accompanies its temperature-induced conformational transition. Our measurements show that heat invokes robust, complex thermal transitions in TRPV1 that include both channel opening and a partial protein unfolding transition and that these two processes are inherently coupled. Our findings support that irreversible protein unfolding, which is generally thought to be destructive to physiological function, is essential to TRPV1 thermal transduction and, possibly, to other strongly temperature-dependent processes in biology.
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Affiliation(s)
- Andrew Mugo
- Department of Physiology and Biophysical Sciences, State University of New York at Buffalo, Buffalo, NY14214
| | - Ryan Chou
- Trinity College of Arts and Sciences, Duke University, Durham, NC27708
| | - Felix Chin
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104
| | - Beiying Liu
- Department of Physiology and Biophysical Sciences, State University of New York at Buffalo, Buffalo, NY14214
| | - Qiu-Xing Jiang
- Department of Physiology and Biophysical Sciences, State University of New York at Buffalo, Buffalo, NY14214
- Hauptman-Woodward Medical Research Institute, Buffalo, NY14203
| | - Feng Qin
- Department of Physiology and Biophysical Sciences, State University of New York at Buffalo, Buffalo, NY14214
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Yeh F, Jara-Oseguera A, Aldrich RW. Implications of a temperature-dependent heat capacity for temperature-gated ion channels. Proc Natl Acad Sci U S A 2023; 120:e2301528120. [PMID: 37279277 PMCID: PMC10268252 DOI: 10.1073/pnas.2301528120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 04/26/2023] [Indexed: 06/08/2023] Open
Abstract
Temperature influences dynamics and state-equilibrium distributions in all molecular processes, and only a relatively narrow range of temperatures is compatible with life-organisms must avoid temperature extremes that can cause physical damage or metabolic disruption. Animals evolved a set of sensory ion channels, many of them in the family of transient receptor potential cation channels that detect biologically relevant changes in temperature with remarkable sensitivity. Depending on the specific ion channel, heating or cooling elicits conformational changes in the channel to enable the flow of cations into sensory neurons, giving rise to electrical signaling and sensory perception. The molecular mechanisms responsible for the heightened temperature-sensitivity in these ion channels, as well as the molecular adaptations that make each channel specifically heat- or cold-activated, are largely unknown. It has been hypothesized that a heat capacity difference (ΔCp) between two conformational states of these biological thermosensors can drive their temperature-sensitivity, but no experimental measurements of ΔCp have been achieved for these channel proteins. Contrary to the general assumption that the ΔCp is constant, measurements from soluble proteins indicate that the ΔCp is likely to be a function of temperature. By investigating the theoretical consequences for a linearly temperature-dependent ΔCp on the open-closed equilibrium of an ion channel, we uncover a range of possible channel behaviors that are consistent with experimental measurements of channel activity and that extend beyond what had been generally assumed to be possible for a simple two-state model, challenging long-held assumptions about ion channel gating models at equilibrium.
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Affiliation(s)
- Frank Yeh
- Institute for Neuroscience, University of Texas at Austin, Austin, TX78712
- Department of Neuroscience, University of Texas at Austin, Austin, TX78712
| | - Andrés Jara-Oseguera
- Institute for Neuroscience, University of Texas at Austin, Austin, TX78712
- Department of Neuroscience, University of Texas at Austin, Austin, TX78712
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX78712
| | - Richard W. Aldrich
- Institute for Neuroscience, University of Texas at Austin, Austin, TX78712
- Department of Neuroscience, University of Texas at Austin, Austin, TX78712
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7
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Abstract
The ability to detect stimuli from the environment plays a pivotal role in our survival. The molecules that allow the detection of such signals include ion channels, which are proteins expressed in different cells and organs. Among these ion channels, the transient receptor potential (TRP) family responds to the presence of diverse chemicals, temperature, and osmotic changes, among others. This family of ion channels includes the TRPV or vanilloid subfamily whose members serve several physiological functions. Although these proteins have been studied intensively for the last two decades, owing to their structural and functional complexities, a number of controversies regarding their function still remain. Here, we discuss some salient features of their regulation in light of these controversies and outline some of the efforts pushing the field forward.
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Affiliation(s)
- Tamara Rosenbaum
- Department of Cognitive Neuroscience, Neuroscience Division, Institute for Cellular Physiology, National Autonomous University of Mexico, Coyoacán, México;
| | - León D Islas
- Department of Physiology, School of Medicine, National Autonomous University of Mexico, Coyoacán, México
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8
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Wohlrab J, Mentel T, Eichner A. Efficiency of cutaneous heat diffusion after local hyperthermia for the treatment of itch. Skin Res Technol 2023; 29:e13277. [PMID: 36823504 PMCID: PMC10155804 DOI: 10.1111/srt.13277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 12/30/2022] [Indexed: 02/05/2023]
Abstract
BACKGROUND Today, itching is understood as an independent sensory perception, which is based on a complex etiology of a disturbed neuronal activity and leads to clinical symptoms. The primary afferents (pruriceptors) have functional overlaps with afferents of thermoregulation (thermoceptors). Thus, an antipruritic effect can be caused by antagonizing heat-sensitive receptors of the skin. The ion channel TRP-subfamily V member 1 (TRPV1) is of particular importance in this context. Repeated heat application can induce irreversible inactivation by unfolding of the protein, causing a persistent functional deficit and thus clinically and therapeutically reducing itch sensation. MATERIAL AND METHODS To demonstrate relevant heat diffusion after local application of heat (45°C to 52°C for 3 and 5 seconds) by a technical medical device, the temperature profile for the relevant skin layer was recorded synchronously on ex vivo human skin using an infrared microscope. RESULTS The results showed that the necessary activation temperature for TRPV1 of (≥43°C) in the upper relevant skin layers was safely reached after 3 and 5 seconds of application time. There were no indications of undesirable thermal effects. CONCLUSION The test results show that the objectified performance of the investigated medical device can be expected to provide the necessary temperature input for the activation of heat-sensitive receptors in the skin. Clinical studies are necessary to prove therapeutic efficacy in the indication pruritus.
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Affiliation(s)
- Johannes Wohlrab
- Department of Dermatology and VenereologyMartin Luther University Halle‐WittenbergHalle (Saale)Germany
- Institute of applied DermatopharmacyMartin Luther University Halle‐WittenbergHalle (Saale)Germany
| | | | - Adina Eichner
- Institute of applied DermatopharmacyMartin Luther University Halle‐WittenbergHalle (Saale)Germany
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9
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Gochman A, Tan X, Bae C, Chen H, Swartz KJ, Jara-Oseguera A. Cannabidiol sensitizes TRPV2 channels to activation by 2-APB. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.27.525817. [PMID: 36747846 PMCID: PMC9900902 DOI: 10.1101/2023.01.27.525817] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The cation-permeable TRPV2 channel is essential for cardiac and immune cells. Cannabidiol (CBD), a non-psychoactive cannabinoid of clinical relevance, is one of the few molecules known to activate TRPV2. Using the patch-clamp technique we discover that CBD can sensitize current responses of the rat TRPV2 channel to the synthetic agonist 2-aminoethoxydiphenyl borate (2- APB) by over two orders of magnitude, without sensitizing channels to activation by moderate (40 ⁰C) heat. Using cryo-EM we uncover a new small-molecule binding site in the pore domain of rTRPV2 that can be occupied by CBD in addition to a nearby CBD site that had already been reported. The TRPV1 and TRPV3 channels share >40% sequence identity with TRPV2 are also activated by 2-APB and CBD, but we only find a strong sensitizing effect of CBD on the response of mouse TRPV3 to 2-APB. Mutations at non-conserved positions between rTRPV2 and rTRPV1 in either the pore domain or the CBD sites failed to confer strong sensitization by CBD in mutant rTRPV1 channels. Together, our results indicate that CBD-dependent sensitization of TRPV2 channels engages multiple channel regions and possibly involves more than one CBD and 2-APB sites. The remarkably robust effect of CBD on TRPV2 and TRPV3 channels offers a promising new tool to both understand and overcome one of the major roadblocks in the study of these channels - their resilience to activation.
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Affiliation(s)
- Aaron Gochman
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892 USA,Current affiliation: Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Xiaofeng Tan
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892 USA
| | - Chanhyung Bae
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892 USA,Current affiliation: Janssen R&D, Biologics Discovery, Spring House, PA, USA
| | - Helen Chen
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, TX, 78712 USA
| | - Kenton J. Swartz
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892 USA
| | - Andrés Jara-Oseguera
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, TX, 78712 USA.,Corresponding author: Andrés Jara-Oseguera ()
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10
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Cowgill J, Chanda B. Charge-voltage curves of Shaker potassium channel are not hysteretic at steady state. J Gen Physiol 2023; 155:213823. [PMID: 36692860 PMCID: PMC9884579 DOI: 10.1085/jgp.202112883] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/16/2022] [Accepted: 01/03/2023] [Indexed: 01/25/2023] Open
Abstract
Charge-voltage curves of many voltage-gated ion channels exhibit hysteresis but such curves are also a direct measure of free energy of channel gating and, hence, should be path-independent. Here, we identify conditions to measure steady-state charge-voltage curves and show that these are curves are not hysteretic. Charged residues in transmembrane segments of voltage-gated ion channels (VGICs) sense and respond to changes in the electric field. The movement of these gating charges underpins voltage-dependent activation and is also a direct metric of the net free-energy of channel activation. However, for most voltage-gated ion channels, the charge-voltage (Q-V) curves appear to be dependent on initial conditions. For instance, Q-V curves of Shaker potassium channel obtained by hyperpolarizing from 0 mV is left-shifted compared to those obtained by depolarizing from a holding potential of -80 mV. This hysteresis in Q-V curves is a common feature of channels in the VGIC superfamily and raises profound questions about channel energetics because the net free-energy of channel gating is a state function and should be path independent. Due to technical limitations, conventional gating current protocols are limited to test pulse durations of <500 ms, which raises the possibility that the dependence of Q-V on initial conditions reflects a lack of equilibration. Others have suggested that the hysteresis is fundamental thermodynamic property of voltage-gated ion channels and reflects energy dissipation due to measurements under non-equilibrium conditions inherent to rapid voltage jumps (Villalba-Galea. 2017. Channels. https://doi.org/10.1080/19336950.2016.1243190). Using an improved gating current and voltage-clamp fluorometry protocols, we show that the gating hysteresis arising from different initial conditions in Shaker potassium channel is eliminated with ultra-long (18-25 s) test pulses. Our study identifies a modified gating current recording protocol to obtain steady-state Q-V curves of a voltage-gated ion channel. Above all, these findings demonstrate that the gating hysteresis in Shaker channel is a kinetic phenomenon rather than a true thermodynamic property of the channel and the charge-voltage curve is a true measure of the net-free energy of channel gating.
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Affiliation(s)
- John Cowgill
- Departments of Anesthesiology, Neuroscience, Biochemistry and Molecular Biophysics, Center for Investigation of Membrane Excitability Diseases, Washington University School of Medicine, St. Louis, MO, USA,John Cowgill:
| | - Baron Chanda
- Departments of Anesthesiology, Neuroscience, Biochemistry and Molecular Biophysics, Center for Investigation of Membrane Excitability Diseases, Washington University School of Medicine, St. Louis, MO, USA,Correspondence to Baron Chanda:
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11
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Progress in the Structural Basis of thermoTRP Channel Polymodal Gating. Int J Mol Sci 2023; 24:ijms24010743. [PMID: 36614186 PMCID: PMC9821180 DOI: 10.3390/ijms24010743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/26/2022] [Accepted: 12/27/2022] [Indexed: 01/03/2023] Open
Abstract
The thermosensory transient receptor potential (thermoTRP) family of ion channels is constituted by several nonselective cation channels that are activated by physical and chemical stimuli functioning as paradigmatic polymodal receptors. Gating of these ion channels is achieved through changes in temperature, osmolarity, voltage, pH, pressure, and by natural or synthetic chemical compounds that directly bind to these proteins to regulate their activity. Given that thermoTRP channels integrate diverse physical and chemical stimuli, a thorough understanding of the molecular mechanisms underlying polymodal gating has been pursued, including the interplay between stimuli and differences between family members. Despite its complexity, recent advances in cryo-electron microscopy techniques are facilitating this endeavor by providing high-resolution structures of these channels in different conformational states induced by ligand binding or temperature that, along with structure-function and molecular dynamics, are starting to shed light on the underlying allosteric gating mechanisms. Because dysfunctional thermoTRP channels play a pivotal role in human diseases such as chronic pain, unveiling the intricacies of allosteric channel gating should facilitate the development of novel drug-based resolving therapies for these disorders.
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12
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Rosenbaum T, Morales-Lázaro SL, Islas LD. TRP channels: a journey towards a molecular understanding of pain. Nat Rev Neurosci 2022; 23:596-610. [PMID: 35831443 DOI: 10.1038/s41583-022-00611-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2022] [Indexed: 12/18/2022]
Abstract
The perception of nociceptive signals, which are translated into pain, plays a fundamental role in the survival of organisms. Because pain is linked to a negative sensation, animals learn to avoid noxious signals. These signals are detected by receptors, which include some members of the transient receptor potential (TRP) family of ion channels that act as transducers of exogenous and endogenous noxious cues. These proteins have been in the focus of the field of physiology for several years, and much knowledge of how they regulate the function of the cell types and organs where they are expressed has been acquired. The last decade has been especially exciting because the 'resolution revolution' has allowed us to learn the molecular intimacies of TRP channels using cryogenic electron microscopy. These findings, in combination with functional studies, have provided insights into the role played by these channels in the generation and maintenance of pain.
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Affiliation(s)
- Tamara Rosenbaum
- Departamento de Neurociencia Cognitiva, Instituto de Fisiología Celular, UNAM, Mexico City, Mexico.
| | - Sara L Morales-Lázaro
- Departamento de Neurociencia Cognitiva, Instituto de Fisiología Celular, UNAM, Mexico City, Mexico
| | - León D Islas
- Departamento de Fisiología, Facultad de Medicina, UNAM, Mexico City, Mexico
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13
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York JM, Zakon HH. OUP accepted manuscript. Genome Biol Evol 2022; 14:6519823. [PMID: 35106545 PMCID: PMC8857925 DOI: 10.1093/gbe/evac009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2022] [Indexed: 11/14/2022] Open
Abstract
Animals rely on their sensory systems to inform them of ecologically relevant environmental variation. In the Southern Ocean, the thermal environment has remained between −1.9 and 5 °C for 15 Myr, yet we have no knowledge of how an Antarctic marine organism might sense their thermal habitat as we have yet to discover a thermosensitive ion channel that gates (opens/closes) below 10 °C. Here, we investigate the evolutionary dynamics of transient receptor potential (TRP) channels, which are the primary thermosensors in animals, within cryonotothenioid fishes—the dominant fish fauna of the Southern Ocean. We found cryonotothenioids have a similar complement of TRP channels as other teleosts (∼28 genes). Previous work has shown that thermosensitive gating in a given channel is species specific, and multiple channels act together to sense the thermal environment. Therefore, we combined evidence of changes in selective pressure, gene gain/loss dynamics, and the first sensory ganglion transcriptome in this clade to identify the best candidate TRP channels that might have a functional dynamic range relevant for frigid Antarctic temperatures. We concluded that TRPV1a, TRPA1b, and TRPM4 are the likeliest putative thermosensors, and found evidence of diversifying selection at sites across these proteins. We also put forward hypotheses for molecular mechanisms of other cryonotothenioid adaptations, such as reduced skeletal calcium deposition, sensing oxidative stress, and unusual magnesium homeostasis. By completing a comprehensive and unbiased survey of these genes, we lay the groundwork for functional characterization and answering long-standing thermodynamic questions of thermosensitive gating and protein adaptation to low temperatures.
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Affiliation(s)
- Julia M York
- Department of Integrative Biology, University of Texas at Austin, USA
- Corresponding author: E-mail:
| | - Harold H Zakon
- Department of Integrative Biology, University of Texas at Austin, USA
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14
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Thermodynamic and structural basis of temperature-dependent gating in TRP channels. Biochem Soc Trans 2021; 49:2211-2219. [PMID: 34623379 DOI: 10.1042/bst20210301] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 09/16/2021] [Accepted: 09/21/2021] [Indexed: 11/17/2022]
Abstract
Living organisms require detecting the environmental thermal clues for survival, allowing them to avoid noxious stimuli or find prey moving in the dark. In mammals, the Transient Receptor Potential ion channels superfamily is constituted by 27 polymodal receptors whose activity is controlled by small ligands, peptide toxins, protons and voltage. The thermoTRP channels subgroup exhibits unparalleled temperature dependence -behaving as heat and cold sensors. Functional studies have dissected their biophysical features in detail, and the advances of single-particle Cryogenic Electron microscopy provided the structural framework required to propose detailed channel gating mechanisms. However, merging structural and functional evidence for temperature-driven gating of thermoTRP channels has been a hard nut to crack, remaining an open question nowadays. Here we revisit the highlights on the study of heat and cold sensing in thermoTRP channels in the light of the structural data that has emerged during recent years.
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15
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Luu DD, Owens AM, Mebrat MD, Van Horn WD. A molecular perspective on identifying TRPV1 thermosensitive regions and disentangling polymodal activation. Temperature (Austin) 2021; 10:67-101. [PMID: 37187836 PMCID: PMC10177694 DOI: 10.1080/23328940.2021.1983354] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 09/10/2021] [Accepted: 09/16/2021] [Indexed: 10/20/2022] Open
Abstract
TRPV1 is a polymodal receptor ion channel that is best known to function as a molecular thermometer. It is activated in diverse ways, including by heat, protons (low pH), and vanilloid compounds, such as capsaicin. In this review, we summarize molecular studies of TRPV1 thermosensing, focusing on the cross-talk between heat and other activation modes. Additional insights from TRPV1 isoforms and non-rodent/non-human TRPV1 ortholog studies are also discussed in this context. While the molecular mechanism of heat activation is still emerging, it is clear that TRPV1 thermosensing is modulated allosterically, i.e., at a distance, with contributions from many distinct regions of the channel. Similarly, current studies identify cross-talk between heat and other TRPV1 activation modes, such as protons and capsaicin, and that these modes can generally be selectively disentangled. In aggregate, this suggests that future TRPV1 molecular studies should define allosteric pathways and provide mechanistic insight, thereby enabling mode-selective manipulation of the polymodal receptor. These advances are anticipated to have significant implications in both basic and applied biomedical sciences.
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Affiliation(s)
- Dustin D. Luu
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
- The Biodesign Institute Virginia G. Piper Center for Personalized Diagnostics,Arizona State University, Tempe, Arizona,USA
| | - Aerial M. Owens
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
- The Biodesign Institute Virginia G. Piper Center for Personalized Diagnostics,Arizona State University, Tempe, Arizona,USA
| | - Mubark D. Mebrat
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
- The Biodesign Institute Virginia G. Piper Center for Personalized Diagnostics,Arizona State University, Tempe, Arizona,USA
| | - Wade D. Van Horn
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
- The Biodesign Institute Virginia G. Piper Center for Personalized Diagnostics,Arizona State University, Tempe, Arizona,USA
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16
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Liu B, Qin F. Identification of a helix-turn-helix motif for high temperature dependence of vanilloid receptor TRPV2. J Physiol 2021; 599:4831-4844. [PMID: 34605028 DOI: 10.1113/jp282073] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 08/26/2021] [Indexed: 12/27/2022] Open
Abstract
Pain and thermosensation rely on temperature-sensitive ion channels at peripheral nerve endings for transducing thermal cues into electrical signals. Members of the transient receptor potential (TRP) family are prominent candidates for temperature transducers in mammals. These thermal TRP channels possess an unprecedentedly steep temperature dependence, allowing them to discriminate small temperature variations. Thermodynamically, it is understood that the strong temperature sensitivity of the channel arises because opening of the channel undergoes reactions involving large enthalpy and entropy changes. However, the underlying molecular mechanisms have remained elusive. Here we investigated the molecular basis for heat activation of TRPV2, a thermal TRP channel in the vanilloid subfamily with the strongest temperature dependence among TRP channels. We unravel a minimum molecular region in the proximal N-terminus which dictates the slope temperature sensitivity of the channel. Structurally, the region comprises a helix-turn-helix motif and is positioned among the TRP helix from the C-terminus, the S2-S3 linker from the transmembrane domain and the ankyrin repeats from the distal N-terminus. Chimeric exchanges of the subregion alone sufficed to diminish the high temperature dependence in the wild-type TRPV2. Our results support a pivotal role for the structural assembly around the TRP domain in the gating of thermal TRP channels by temperature. The findings also shed insight into how the proximal N-terminal domain plays its role in the heat activation of vanilloid receptors. KEY POINTS: The vanilloid receptor subtype 2 (TRPV2) is a heat-sensitive transient receptor potential (TRP) channel with the strongest temperature dependence among thermal TRP channels. The channel also has a high temperature activation threshold above 50°C which has rendered it difficult to study by conventional patch-clamp methods. Here we utilize fast laser temperature jumps to address the challenges of technical accessibility and explore the molecular basis underlying the high temperature dependence of the channel. We unravel a short helix-turn-helix motif in the proximal N-terminus, which controls the heat activation profile of the channel. Chimeric exchanges of the subregion alone sufficed to diminish the high temperature dependence in the wild-type TRPV2. Our results provide insights on how the proximal N-terminal domain plays its role in the heat activation of vanilloid receptors.
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Affiliation(s)
- Beiying Liu
- Department of Physiology and Biophysical Sciences, State University of New York at Buffalo, Buffalo, NY, 14214, USA
| | - Feng Qin
- Department of Physiology and Biophysical Sciences, State University of New York at Buffalo, Buffalo, NY, 14214, USA
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17
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Hapgood JE, Chabal C, Dunbar PJ. The Effectiveness of Thermal Neuromodulation Using Precise Heat in the Treatment of Chronic Low Back Pain Over 60 Days: An In-Home User Trial. J Pain Res 2021; 14:2793-2806. [PMID: 34526814 PMCID: PMC8436780 DOI: 10.2147/jpr.s316865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/16/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose Two previous independent double-blind randomized studies demonstrated that thermal neuromodulation using high temperature pulsed heat reduced pain in subjects with chronic low back pain. The present study examined the effects of high temperature pulsed heat via an experimental device in a real-world In-Home Use Trial (IHUT) over a sixty-day period. Materials and Methods This in-home study recruited 34 subjects with chronic low back pain, provided them with an experimental device that delivered treatment session of high temperature pulsed heat up to 45°C, and followed them for eight weeks. Subjects were allowed to use the device as needed. Primary outcome was pain rating as measured by the 11-point Numeric Pain Scale at baseline, four and eight weeks of treatment. The secondary outcome measures were the interference with daily living components of the Brief Pain Inventory at baseline versus eight weeks of treatment. Results Thirty-two subjects completed the study. Pain levels were 5.81 at baseline, 2.79 at four weeks and 2.25 at eight weeks. All changes in pain levels between baseline and four weeks, baseline, and eight weeks and between four and eight weeks were statistically significant (p < 0.05). At eight weeks, the seven components of pain interference with activities of daily living and pain interference with walking were statistically reduced (P < 0.05). About 72% of subjects reported a single 30-minute treatment session produced over 3 hours of pain relief. Conclusion An eight-week in-home trial of high-temperature thermal modulation devices produced significant reductions in pain and pain interference with activities of daily living, an important measure of function. Efforts were made to control and reduce study contamination. This study provides important initial data for long-term outcome studies of thermal neuromodulation using high temperature pulsed heat to treat low back pain and to improve subject function and demonstrated that individuals with chronic pain can effectively self-manage pain.
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18
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Heat-dependent opening of TRPV1 in the presence of capsaicin. Nat Struct Mol Biol 2021; 28:554-563. [PMID: 34239123 PMCID: PMC8335751 DOI: 10.1038/s41594-021-00616-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/03/2021] [Indexed: 02/06/2023]
Abstract
Transient receptor potential vanilloid member 1 (TRPV1) is a Ca2+-permeable cation channel that serves as the primary heat and capsaicin sensor in humans. Using cryo-EM, we have determined the structures of apo and capsaicin-bound full-length rat TRPV1 reconstituted into lipid nanodiscs over a range of temperatures. This has allowed us to visualize the noxious heat-induced opening of TRPV1 in the presence of capsaicin. Notably, noxious heat-dependent TRPV1 opening comprises stepwise conformational transitions. Global conformational changes across multiple subdomains of TRPV1 are followed by the rearrangement of the outer pore, leading to gate opening. Solvent-accessible surface area analyses and functional studies suggest that a subset of residues form an interaction network that is directly involved in heat sensing. Our study provides a glimpse of the molecular principles underlying noxious physical and chemical stimuli sensing by TRPV1, which can be extended to other thermal sensing ion channels.
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19
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Cao E. Structural mechanisms of transient receptor potential ion channels. J Gen Physiol 2021; 152:133640. [PMID: 31972006 PMCID: PMC7054860 DOI: 10.1085/jgp.201811998] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 01/03/2020] [Indexed: 12/26/2022] Open
Abstract
Transient receptor potential (TRP) ion channels are evolutionarily ancient sensory proteins that detect and integrate a wide range of physical and chemical stimuli. TRP channels are fundamental for numerous biological processes and are therefore associated with a multitude of inherited and acquired human disorders. In contrast to many other major ion channel families, high-resolution structures of TRP channels were not available before 2013. Remarkably, however, the subsequent “resolution revolution” in cryo-EM has led to an explosion of TRP structures in the last few years. These structures have confirmed that TRP channels assemble as tetramers and resemble voltage-gated ion channels in their overall architecture. But beyond the relatively conserved transmembrane core embedded within the lipid bilayer, each TRP subtype appears to be endowed with a unique set of soluble domains that may confer diverse regulatory mechanisms. Importantly, TRP channel structures have revealed sites and mechanisms of action of numerous synthetic and natural compounds, as well as those for endogenous ligands such as lipids, Ca2+, and calmodulin. Here, I discuss these recent findings with a particular focus on the conserved transmembrane region and how these structures may help to rationally target this important class of ion channels for the treatment of numerous human conditions.
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Affiliation(s)
- Erhu Cao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT
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20
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Molecular sensors for temperature detection during behavioral thermoregulation in turtle embryos. Curr Biol 2021; 31:2995-3003.e4. [PMID: 34015251 DOI: 10.1016/j.cub.2021.04.054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/29/2021] [Accepted: 04/21/2021] [Indexed: 01/14/2023]
Abstract
Temperature sensing is essential for the survival of living organisms. Some reptile embryos can reposition themselves within the egg to seek optimal temperatures, but the molecular sensors involved in this temperature detection remain unknown. Here, we show that such thermotaxic behavior is directly determined by the activation of two heat-sensitive ion channels of the turtle: the transient receptor potential ankyrin 1 (MrTRPA1) and transient receptor potential vanilloid-1 (MrTRPV1). These two TRP channels were found to exhibit distinctive distributions among turtle dorsal root ganglion (DRG) neurons. Additionally, our laser irradiation assays illustrated that the heat activation thresholds of MrTRPA1 and MrTRPV1 are consistent with the mild (28-33°C) and noxious (>33°C) heat determined by behavioral tests, respectively. Further pharmacological studies have demonstrated that ligand-induced intervention of MrTRPA1 or MrTRPV1 is sufficient to mimic heat stimuli or block temperature signaling, causing changes in embryo movement. These findings indicate that the initiation of thermotaxic response in turtle embryos relies on a delicate functional balance between the heat activation of MrTRPA1 and MrTRPV1. Our study reveals, for the first time, a unique molecular mechanism underlying thermal detection: the two TRP channels act as a physiological tandem to control the thermotaxic behavior of turtle embryos.
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21
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Fischer MJM, Ciotu CI, Szallasi A. The Mysteries of Capsaicin-Sensitive Afferents. Front Physiol 2020; 11:554195. [PMID: 33391007 PMCID: PMC7772409 DOI: 10.3389/fphys.2020.554195] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 11/13/2020] [Indexed: 12/11/2022] Open
Abstract
A fundamental subdivision of nociceptive sensory neurons is named after their unique sensitivity to capsaicin, the pungent ingredient in hot chili peppers: these are the capsaicin-sensitive afferents. The initial excitation by capsaicin of these neurons manifested as burning pain sensation is followed by a lasting refractory state, traditionally referred to as "capsaicin desensitization," during which the previously excited neurons are unresponsive not only to capsaicin but a variety of unrelated stimuli including noxious heat. The long sought-after capsaicin receptor, now known as TRPV1 (transient receptor potential cation channel, subfamily V member 1), was cloned more than two decades ago. The substantial reduction of the inflammatory phenotype of Trpv1 knockout mice has spurred extensive efforts in the pharmaceutical industry to develop small molecule TRPV1 antagonists. However, adverse effects, most importantly hyperthermia and burn injuries, have so far prevented any compounds from progressing beyond Phase 2. There is increasing evidence that these limitations can be at least partially overcome by approaches outside of the mainstream pharmaceutical development, providing novel therapeutic options through TRPV1. Although ablation of the whole TRPV1-expressing nerve population by high dose capsaicin, or more selectively by intersectional genetics, has allowed researchers to investigate the functions of capsaicin-sensitive afferents in health and disease, several "mysteries" remain unsolved to date, including the molecular underpinnings of "capsaicin desensitization," and the exact role these nerves play in thermoregulation and heat sensation. This review tries to shed some light on these capsaicin mechanisms.
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Affiliation(s)
- Michael J. M. Fischer
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Cosmin I. Ciotu
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Arpad Szallasi
- 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
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22
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Jiang Y, Idikuda V, Chowdhury S, Chanda B. Activation of the archaeal ion channel MthK is exquisitely regulated by temperature. eLife 2020; 9:e59055. [PMID: 33274718 PMCID: PMC7717905 DOI: 10.7554/elife.59055] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 11/17/2020] [Indexed: 11/13/2022] Open
Abstract
Physiological response to thermal stimuli in mammals is mediated by a structurally diverse class of ion channels, many of which exhibit polymodal behavior. To probe the diversity of biophysical mechanisms of temperature-sensitivity, we characterized the temperature-dependent activation of MthK, a two transmembrane calcium-activated potassium channel from thermophilic archaebacteria. Our functional complementation studies show that these channels are more efficient at rescuing K+ transport at 37°C than at 24°C. Electrophysiological activity of the purified MthK is extremely sensitive (Q10 >100) to heating particularly at low-calcium concentrations whereas channels lacking the calcium-sensing RCK domain are practically insensitive. By analyzing single-channel activities at limiting calcium concentrations, we find that temperature alters the coupling between the cytoplasmic RCK domains and the pore domain. These findings reveal a hitherto unexplored mechanism of temperature-dependent regulation of ion channel gating and shed light on ancient origins of temperature-sensitivity.
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Affiliation(s)
- Yihao Jiang
- Department of Anesthesiology, Washington University School of MedicineSt. LouisUnited States
- Center for the Investigation of Membrane Excitability Diseases (CIMED)St. LouisUnited States
| | - Vinay Idikuda
- Department of Anesthesiology, Washington University School of MedicineSt. LouisUnited States
- Center for the Investigation of Membrane Excitability Diseases (CIMED)St. LouisUnited States
| | - Sandipan Chowdhury
- Department of Anesthesiology, Washington University School of MedicineSt. LouisUnited States
- Center for the Investigation of Membrane Excitability Diseases (CIMED)St. LouisUnited States
| | - Baron Chanda
- Department of Anesthesiology, Washington University School of MedicineSt. LouisUnited States
- Center for the Investigation of Membrane Excitability Diseases (CIMED)St. LouisUnited States
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23
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Zubcevic L. TRP Channels, Conformational Flexibility, and the Lipid Membrane. J Membr Biol 2020; 253:299-308. [DOI: 10.1007/s00232-020-00127-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 06/11/2020] [Indexed: 02/06/2023]
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24
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Pumroy RA, Fluck EC, Ahmed T, Moiseenkova-Bell VY. Structural insights into the gating mechanisms of TRPV channels. Cell Calcium 2020; 87:102168. [PMID: 32004816 DOI: 10.1016/j.ceca.2020.102168] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/22/2020] [Accepted: 01/22/2020] [Indexed: 02/06/2023]
Abstract
Transient Receptor Potential channels from the vanilloid subfamily (TRPV) are a group of cation channels modulated by a variety of endogenous stimuli as well as a range of natural and synthetic compounds. Their roles in human health make them of keen interest, particularly from a pharmacological perspective. However, despite this interest, the complexity of these channels has made it difficult to obtain high resolution structures until recently. With the cryo-EM resolution revolution, TRPV channel structural biology has blossomed to produce dozens of structures, covering every TRPV family member and a variety of approaches to examining channel modulation. Here, we review all currently available TRPV structures and the mechanistic insights into gating that they reveal.
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Affiliation(s)
- Ruth A Pumroy
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
| | - Edwin C Fluck
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
| | - Tofayel Ahmed
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
| | - Vera Y Moiseenkova-Bell
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA.
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25
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Garami A, Shimansky YP, Rumbus Z, Vizin RCL, Farkas N, Hegyi J, Szakacs Z, Solymar M, Csenkey A, Chiche DA, Kapil R, Kyle DJ, Van Horn WD, Hegyi P, Romanovsky AA. Hyperthermia induced by transient receptor potential vanilloid-1 (TRPV1) antagonists in human clinical trials: Insights from mathematical modeling and meta-analysis. Pharmacol Ther 2020; 208:107474. [PMID: 31926897 DOI: 10.1016/j.pharmthera.2020.107474] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 12/23/2019] [Indexed: 02/06/2023]
Abstract
Antagonists of the transient receptor potential vanilloid-1 (TRPV1) channel alter body temperature (Tb) in laboratory animals and humans: most cause hyperthermia; some produce hypothermia; and yet others have no effect. TRPV1 can be activated by capsaicin (CAP), protons (low pH), and heat. First-generation (polymodal) TRPV1 antagonists potently block all three TRPV1 activation modes. Second-generation (mode-selective) TRPV1 antagonists potently block channel activation by CAP, but exert different effects (e.g., potentiation, no effect, or low-potency inhibition) in the proton mode, heat mode, or both. Based on our earlier studies in rats, only one mode of TRPV1 activation - by protons - is involved in thermoregulatory responses to TRPV1 antagonists. In rats, compounds that potently block, potentiate, or have no effect on proton activation cause hyperthermia, hypothermia, or no effect on Tb, respectively. A Tb response occurs when a TRPV1 antagonist blocks (in case of hyperthermia) or potentiates (hypothermia) the tonic TRPV1 activation by protons somewhere in the trunk, perhaps in muscles, and - via the acido-antithermogenic and acido-antivasoconstrictor reflexes - modulates thermogenesis and skin vasoconstriction. In this work, we used a mathematical model to analyze Tb data from human clinical trials of TRPV1 antagonists. The analysis suggests that, in humans, the hyperthermic effect depends on the antagonist's potency to block TRPV1 activation not only by protons, but also by heat, while the CAP activation mode is uninvolved. Whereas in rats TRPV1 drives thermoeffectors by mediating pH signals from the trunk, but not Tb signals, our analysis suggests that TRPV1 mediates both pH and thermal signals driving thermoregulation in humans. Hence, in humans (but not in rats), TRPV1 is likely to serve as a thermosensor of the thermoregulation system. We also conducted a meta-analysis of Tb data from human trials and found that polymodal TRPV1 antagonists (ABT-102, AZD1386, and V116517) increase Tb, whereas the mode-selective blocker NEO6860 does not. Several strategies of harnessing the thermoregulatory effects of TRPV1 antagonists in humans are discussed.
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Affiliation(s)
- Andras Garami
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary.
| | - Yury P Shimansky
- Department of Neurobiology, Barrow Neurological Institute, Dignity Health, Phoenix, AZ, USA
| | - Zoltan Rumbus
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Robson C L Vizin
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Dignity Health, Phoenix, AZ, USA
| | - Nelli Farkas
- Institute for Translational Medicine, Medical School and Szentagothai Research Centre, University of Pecs, Pecs, Hungary
| | - Judit Hegyi
- Institute for Translational Medicine, Medical School and Szentagothai Research Centre, University of Pecs, Pecs, Hungary
| | - Zsolt Szakacs
- Institute for Translational Medicine, Medical School and Szentagothai Research Centre, University of Pecs, Pecs, Hungary
| | - Margit Solymar
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Alexandra Csenkey
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | | | | | | | - Wade D Van Horn
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
| | - Peter Hegyi
- Institute for Translational Medicine, Medical School and Szentagothai Research Centre, University of Pecs, Pecs, Hungary; Department of Translational Medicine, First Department of Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Andrej A Romanovsky
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Dignity Health, Phoenix, AZ, USA; School of Molecular Sciences, Arizona State University, Tempe, AZ, USA; Zharko Pharma Inc., Olympia, WA, USA.
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26
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Ladrón-de-Guevara E, Dominguez L, Rangel-Yescas GE, Fernández-Velasco DA, Torres-Larios A, Rosenbaum T, Islas LD. The Contribution of the Ankyrin Repeat Domain of TRPV1 as a Thermal Module. Biophys J 2019; 118:836-845. [PMID: 31757360 DOI: 10.1016/j.bpj.2019.10.041] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 10/10/2019] [Accepted: 10/30/2019] [Indexed: 12/22/2022] Open
Abstract
The TRPV1 cation nonselective ion channel plays an essential role in thermosensation and perception of other noxious stimuli. TRPV1 can be activated by low extracellular pH, high temperature, or naturally occurring pungent molecules such as allicin, capsaicin, or resiniferatoxin. Its noxious thermal sensitivity makes it an important participant as a thermal sensor in mammals. However, details of the mechanism of channel activation by increases in temperature remain unclear. Here, we used a combination of approaches to try to understand the role of the ankyrin repeat domain (ARD) in channel behavior. First, a computational modeling approach by coarse-grained molecular dynamics simulation of the whole TRPV1 embedded in a phosphatidylcholine and phosphatidylethanolamine membrane provides insight into the dynamics of this channel domain. Global analysis of the structural ensemble shows that the ARD is a region that sustains high fluctuations during dynamics at different temperatures. We then performed biochemical and thermal stability studies of the purified ARD by the means of circular dichroism and tryptophan fluorescence and demonstrate that this region undergoes structural changes at similar temperatures that lead to TRPV1 activation. Our data suggest that the ARD is a dynamic module and that it may participate in controlling the temperature sensitivity of TRPV1.
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Affiliation(s)
| | - Laura Dominguez
- Facultad de Química, Departamento de Fisicoquímica, Mexico City, Mexico
| | | | | | - Alfredo Torres-Larios
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Tamara Rosenbaum
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Leon D Islas
- Facultad de Medicina, Departamento de Fisiología, Mexico City, Mexico.
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27
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Macikova L, Vyklicka L, Barvik I, Sobolevsky AI, Vlachova V. Cytoplasmic Inter-Subunit Interface Controls Use-Dependence of Thermal Activation of TRPV3 Channel. Int J Mol Sci 2019; 20:E3990. [PMID: 31426314 PMCID: PMC6719031 DOI: 10.3390/ijms20163990] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 02/07/2023] Open
Abstract
The vanilloid transient receptor potential channel TRPV3 is a putative molecular thermosensor widely considered to be involved in cutaneous sensation, skin homeostasis, nociception, and pruritus. Repeated stimulation of TRPV3 by high temperatures above 50 °C progressively increases its responses and shifts the activation threshold to physiological temperatures. This use-dependence does not occur in the related heat-sensitive TRPV1 channel in which responses decrease, and the activation threshold is retained above 40 °C during activations. By combining structure-based mutagenesis, electrophysiology, and molecular modeling, we showed that chimeric replacement of the residues from the TRPV3 cytoplasmic inter-subunit interface (N251-E257) with the homologous residues of TRPV1 resulted in channels that, similarly to TRPV1, exhibited a lowered thermal threshold, were sensitized, and failed to close completely after intense stimulation. Crosslinking of this interface by the engineered disulfide bridge between substituted cysteines F259C and V385C (or, to a lesser extent, Y382C) locked the channel in an open state. On the other hand, mutation of a single residue within this region (E736) resulted in heat resistant channels. We propose that alterations in the cytoplasmic inter-subunit interface produce shifts in the channel gating equilibrium and that this domain is critical for the use-dependence of the heat sensitivity of TRPV3.
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Affiliation(s)
- Lucie Macikova
- Department of Cellular Neurophysiology, Institute of Physiology Czech Academy of Sciences, 142 20 Prague, Czech Republic
- Department of Physiology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Lenka Vyklicka
- Department of Cellular Neurophysiology, Institute of Physiology Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Ivan Barvik
- Division of Biomolecular Physics, Institute of Physics, Faculty of Mathematics and Physics, Charles University, 121 16 Prague, Czech Republic
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Viktorie Vlachova
- Department of Cellular Neurophysiology, Institute of Physiology Czech Academy of Sciences, 142 20 Prague, Czech Republic.
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28
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Luo L, Wang Y, Li B, Xu L, Kamau PM, Zheng J, Yang F, Yang S, Lai R. Molecular basis for heat desensitization of TRPV1 ion channels. Nat Commun 2019; 10:2134. [PMID: 31086183 PMCID: PMC6513986 DOI: 10.1038/s41467-019-09965-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Accepted: 04/09/2019] [Indexed: 12/26/2022] Open
Abstract
The transient receptor potential vanilloid 1 (TRPV1) ion channel is a prototypical molecular sensor for noxious heat in mammals. Its role in sustained heat response remains poorly understood, because rapid heat-induced desensitization (Dh) follows tightly heat-induced activation (Ah). To understand the physiological role and structural basis of Dh, we carried out a comparative study of TRPV1 channels in mouse (mV1) and those in platypus (pV1), which naturally lacks Dh. Here we show that a temperature-sensitive interaction between the N- and C-terminal domains of mV1 but not pV1 drives a conformational rearrangement in the pore leading to Dh. We further show that knock-in mice expressing pV1 sensed heat normally but suffered scald damages in a hot environment. Our findings suggest that Dh evolved late during evolution as a protective mechanism and a delicate balance between Ah and Dh is crucial for mammals to sense and respond to noxious heat.
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Affiliation(s)
- Lei Luo
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, 650223, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yunfei Wang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, 650223, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bowen Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, 650223, China
| | - Lizhen Xu
- Key Laboratory of Medical Neurobiology, Department of Biophysics and Kidney Disease Center, First Affiliated Hospital, Institute of Neuroscience, National Health Commission and Chinese Academy of Medical Sciences, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China
| | - Peter Muiruri Kamau
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, 650223, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jie Zheng
- Department of Physiology and Membrane Biology, University of California, Davis, CA, 95616, USA.
| | - Fan Yang
- Key Laboratory of Medical Neurobiology, Department of Biophysics and Kidney Disease Center, First Affiliated Hospital, Institute of Neuroscience, National Health Commission and Chinese Academy of Medical Sciences, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China.
| | - Shilong Yang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, 650223, China.
| | - Ren Lai
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, 650223, China.
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29
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Zubcevic L, Borschel WF, Hsu AL, Borgnia MJ, Lee SY. Regulatory switch at the cytoplasmic interface controls TRPV channel gating. eLife 2019; 8:47746. [PMID: 31070581 PMCID: PMC6538378 DOI: 10.7554/elife.47746] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 05/08/2019] [Indexed: 12/12/2022] Open
Abstract
Temperature-sensitive transient receptor potential vanilloid (thermoTRPV) channels are activated by ligands and heat, and are involved in various physiological processes. ThermoTRPV channels possess a large cytoplasmic ring consisting of N-terminal ankyrin repeat domains (ARD) and C-terminal domains (CTD). The cytoplasmic inter-protomer interface is unique and consists of a CTD coiled around a β-sheet which makes contacts with the neighboring ARD. Despite much existing evidence that the cytoplasmic ring is important for thermoTRPV function, the mechanism by which this unique structure is involved in thermoTRPV gating has not been clear. Here, we present cryo-EM and electrophysiological studies which demonstrate that TRPV3 gating involves large rearrangements at the cytoplasmic inter-protomer interface and that this motion triggers coupling between cytoplasmic and transmembrane domains, priming the channel for opening. Furthermore, our studies unveil the role of this interface in the distinct biophysical and physiological properties of individual thermoTRPV subtypes.
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Affiliation(s)
- Lejla Zubcevic
- Department of Biochemistry, Duke University School of Medicine, Durham, United States
| | - William F Borschel
- Department of Biochemistry, Duke University School of Medicine, Durham, United States
| | - Allen L Hsu
- Genome Integrity and Structural Biology Laboratory, Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, United States
| | - Mario J Borgnia
- Department of Biochemistry, Duke University School of Medicine, Durham, United States.,Genome Integrity and Structural Biology Laboratory, Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, United States
| | - Seok-Yong Lee
- Department of Biochemistry, Duke University School of Medicine, Durham, United States
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30
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García-Ávila M, Islas LD. What is new about mild temperature sensing? A review of recent findings. Temperature (Austin) 2019; 6:132-141. [PMID: 31286024 PMCID: PMC6601417 DOI: 10.1080/23328940.2019.1607490] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/02/2019] [Accepted: 04/05/2019] [Indexed: 12/15/2022] Open
Abstract
The superfamily of Transient Receptor Potential (TRP) channels is composed by a group of calcium-permeable ionic channels with a generally shared topology. The thermoTRP channels are a subgroup of 11 members, found in the TRPA, TRPV, TRPC, and TRPM subfamilies. Historically, members of this subgroup have been classified as cold, warm or hot-specific temperature sensors. Recently, new experimental results have shown that the role that has been given to the thermoTRPs in thermosensation is not necessarily strict. In addition, it has been shown that these channels activate over temperature ranges, which can have variations depending on the species and the interaction with a specific biological context. Investigation of these interactions could help to elucidate the mechanisms of activation by temperature, which remains uncertain. Abbreviations: Cryo-EM: Cryogenic electron microscopy; DRG: Dorsal root ganglia; H: Human; ROS: Reactive Oxygen Species; TG: Trigeminal ganglia; TRP: Transient Receptor Potential; TRPA: TRP ankyrin; TRPV: TRP vanilloid; TRPC: TRP canonical; TRPM: TRP melastatin.
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Affiliation(s)
| | - León D. Islas
- Departamento de Fisiología, Facultad de Medicina, UNAM, México City, México
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31
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Stan RC, Françoso KS, Alves RPS, Ferreira LCS, Soares IS, de Camargo MM. Febrile temperatures increase in vitro antibody affinity for malarial and dengue antigens. PLoS Negl Trop Dis 2019; 13:e0007239. [PMID: 30943193 PMCID: PMC6464238 DOI: 10.1371/journal.pntd.0007239] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 04/15/2019] [Accepted: 02/12/2019] [Indexed: 01/03/2023] Open
Abstract
Fever is a regulated increase of the body temperature resulting from both infectious and non-infectious causes. Fever is known to play a role in modulating immune responses to infection, but the potential of febrile temperatures in regulating antigen binding affinity to antibodies has not been explored. Here we investigated this process under in vitro conditions using Isothermal titration calorimetry and ELISA. We used selected malarial and dengue antigens against specific monoclonal antibodies, and observed a marked increase in the affinity of these antibody-antigen complexes at 40°C, compared to physiological (37°C) or pathophysiological temperatures (42°C). Induced thermal equilibration of the protein partners at these temperatures in vitro, prior to measurements, further increased their binding affinity. These results suggest another positive and adaptive role for fever in vivo, and highlight the favourable role of thermal priming in enhancing protein-protein affinity for samples with limited availability.
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Affiliation(s)
- Razvan C. Stan
- Department of Immunology, Institute for Biomedical Sciences, University of São Paulo, Brazil
| | - Katia S. Françoso
- Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, Brazil
| | - Rubens P. S. Alves
- Department of Microbiology, Institute for Biomedical Sciences, University of São Paulo, Brazil
| | - Luís Carlos S. Ferreira
- Department of Microbiology, Institute for Biomedical Sciences, University of São Paulo, Brazil
| | - Irene S. Soares
- Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, Brazil
| | - Maristela M. de Camargo
- Department of Immunology, Institute for Biomedical Sciences, University of São Paulo, Brazil
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32
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Affiliation(s)
- Razvan C. Stan
- Immunology DepartmentUniversity of São Paulo Brazil
- Cantacuzino Military-Medical Research-Development National Institute, Bucharest Romania
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33
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Zheng W, Wen H. Heat activation mechanism of TRPV1: New insights from molecular dynamics simulation. Temperature (Austin) 2019; 6:120-131. [PMID: 31286023 DOI: 10.1080/23328940.2019.1578634] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/30/2018] [Accepted: 01/30/2019] [Indexed: 02/07/2023] Open
Abstract
As a member of the transient receptor potential (TRP) channels superfamily, the TRPV1 channel undergoes a closed-to-open gating transition in response to various physical and chemical stimuli including heat. Thanks to recent progress in cryo-electron microscopy, high-resolution structures are becoming available for various TRP channels including TRPV1. This has enabled us to study the molecular mechanism of TRPV1 channel gating by using molecular simulation. Here we review recent progress in molecular simulations of TRPV1 channel by us and others, with focus on our molecular dynamics (MD) simulations of TRPV1 at different temperatures. While no consensus has been reached on the heat activation mechanism of TRPV1, the simulations have offered specific predictions and models for future experimental studies to test.
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Affiliation(s)
- Wenjun Zheng
- Department of Physics, State University of New York at Buffalo, Buffalo, NY, USA
| | - Han Wen
- Department of Physics, State University of New York at Buffalo, Buffalo, NY, USA
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34
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Zhang F, Swartz KJ, Jara-Oseguera A. Conserved allosteric pathways for activation of TRPV3 revealed through engineering vanilloid-sensitivity. eLife 2019; 8:42756. [PMID: 30644819 PMCID: PMC6333442 DOI: 10.7554/elife.42756] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 01/02/2019] [Indexed: 01/07/2023] Open
Abstract
The Transient Receptor Potential Vanilloid 1 (TRPV) channel is activated by an array of stimuli, including heat and vanilloid compounds. The TRPV1 homologues TRPV2 and TRPV3 are also activated by heat, but sensitivity to vanilloids and many other agonists is not conserved among TRPV subfamily members. It was recently discovered that four mutations in TRPV2 are sufficient to render the channel sensitive to the TRPV1-specific vanilloid agonist resiniferatoxin (RTx). Here, we show that mutation of six residues in TRPV3 corresponding to the vanilloid site in TRPV1 is sufficient to engineer RTx binding. However, robust activation of TRPV3 by RTx requires facilitation of channel opening by introducing mutations in the pore, temperatures > 30°C, or sensitization with another agonist. Our results demonstrate that the energetics of channel activation can determine the apparent sensitivity to a stimulus and suggest that allosteric pathways for activation are conserved in the TRPV family.
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Affiliation(s)
- Feng Zhang
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States.,Department of Biochemistry, University of Utah, Salt Lake City, United States
| | - Kenton Jon Swartz
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Andres Jara-Oseguera
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
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35
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Mucke HA. Drug Repurposing Patent Applications July–September 2018. Assay Drug Dev Technol 2018; 16:472-477. [DOI: 10.1089/adt.2018.29083.pq3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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