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Liu H, Fu M, Zhang Y, You Q, Wang L. Small molecules targeting canonical transient receptor potential channels: an update. Drug Discov Today 2024; 29:103951. [PMID: 38514041 DOI: 10.1016/j.drudis.2024.103951] [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: 10/25/2023] [Revised: 03/06/2024] [Accepted: 03/14/2024] [Indexed: 03/23/2024]
Abstract
Transient receptor potential canonical (TRPC) channels belong to an important class of non-selective cation channels. This channel family consists of multiple members that widely participate in various physiological and pathological processes. Previous studies have uncovered the intricate regulation of these channels, as well as the spatial arrangement of TRPCs and the binding sites for various small molecule compounds. Multiple small molecules have been identified as selective agonists or inhibitors targeting different subtypes of TRPC, including potential preclinical drug candidates. This review covers recent advancements in the understanding of TRPC regulation and structure and the discovery of TRPC small molecules over the past few years, with the aim of facilitating research on TRPCs and small-molecule drug discovery.
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Affiliation(s)
- Hua Liu
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China; Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Min Fu
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China; Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Yifan Zhang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China; Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Qidong You
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China; Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
| | - Lei Wang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China; Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
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Rohacs T. Phosphoinositide Regulation of TRP Channels: A Functional Overview in the Structural Era. Annu Rev Physiol 2024; 86:329-355. [PMID: 37871124 DOI: 10.1146/annurev-physiol-042022-013956] [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] [Indexed: 10/25/2023]
Abstract
Transient receptor potential (TRP) ion channels have diverse activation mechanisms including physical stimuli, such as high or low temperatures, and a variety of intracellular signaling molecules. Regulation by phosphoinositides and their derivatives is their only known common regulatory feature. For most TRP channels, phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] serves as a cofactor required for activity. Such dependence on PI(4,5)P2 has been demonstrated for members of the TRPM subfamily and for the epithelial TRPV5 and TRPV6 channels. Intracellular TRPML channels show specific activation by PI(3,5)P2. Structural studies uncovered the PI(4,5)P2 and PI(3,5)P2 binding sites for these channels and shed light on the mechanism of channel opening. PI(4,5)P2 regulation of TRPV1-4 as well as some TRPC channels is more complex, involving both positive and negative effects. This review discusses the functional roles of phosphoinositides in TRP channel regulation and molecular insights gained from recent cryo-electron microscopy structures.
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Affiliation(s)
- Tibor Rohacs
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey;
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3
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Kang H, Kim J, Park CH, Jeong B, So I. Direct modulation of TRPC ion channels by Gα proteins. Front Physiol 2024; 15:1362987. [PMID: 38384797 PMCID: PMC10880550 DOI: 10.3389/fphys.2024.1362987] [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: 12/29/2023] [Accepted: 01/26/2024] [Indexed: 02/23/2024] Open
Abstract
GPCR-Gi protein pathways are involved in the regulation of vagus muscarinic pathway under physiological conditions and are closely associated with the regulation of internal visceral organs. The muscarinic receptor-operated cationic channel is important in GPCR-Gi protein signal transduction as it decreases heart rate and increases GI rhythm frequency. In the SA node of the heart, acetylcholine binds to the M2 receptor and the released Gβγ activates GIRK (I(K,ACh)) channel, inducing a negative chronotropic action. In gastric smooth muscle, there are two muscarinic acetylcholine receptor (mAChR) subtypes, M2 and M3. M2 receptor activates the muscarinic receptor-operated nonselective cationic current (mIcat, NSCC(ACh)) and induces positive chronotropic effect. Meanwhile, M3 receptor induces hydrolysis of PIP2 and releases DAG and IP3. This IP3 increases intracellular Ca2+ and then leads to contraction of GI smooth muscles. The activation of mIcat is inhibited by anti-Gi/o protein antibodies in GI smooth muscle, indicating the involvement of Gαi/o protein in the activation of mIcat. TRPC4 channel is a molecular candidate for mIcat and can be directly activated by constitutively active Gαi QL proteins. TRPC4 and TRPC5 belong to the same subfamily and both are activated by Gi/o proteins. Initial studies suggested that the binding sites for G protein exist at the rib helix or the CIRB domain of TRPC4/5 channels. However, recent cryo-EM structure showed that IYY58-60 amino acids at ARD of TRPC5 binds with Gi3 protein. Considering the expression of TRPC4/5 in the brain, the direct G protein activation on TRPC4/5 is important in terms of neurophysiology. TRPC4/5 channels are also suggested as a coincidence detector for Gi and Gq pathway as Gq pathway increases intracellular Ca2+ and the increased Ca2+ facilitates the activation of TRPC4/5 channels. More complicated situation would occur when GIRK, KCNQ2/3 (IM) and TRPC4/5 channels are co-activated by stimulation of muscarinic receptors at the acetylcholine-releasing nerve terminals. This review highlights the effects of GPCR-Gi protein pathway, including dopamine, μ-opioid, serotonin, glutamate, GABA, on various oragns, and it emphasizes the importance of considering TRPC4/5 channels as crucial players in the field of neuroscience.
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Affiliation(s)
- Hana Kang
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jinhyeong Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Christine Haewon Park
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
| | - Byeongseok Jeong
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Insuk So
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
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Shen M, Li L, Li Y, Gu X, Bai L, Xia C, Xiong W, Zuo Z. Discovery of potential novel TRPC5 inhibitors by virtual screening and bioassay. Bioorg Med Chem 2023; 94:117477. [PMID: 37738708 DOI: 10.1016/j.bmc.2023.117477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/22/2023] [Accepted: 09/13/2023] [Indexed: 09/24/2023]
Abstract
The transient receptor potential canonical channel 5 (TRPC5), a member of the TRPC family, plays a crucial role in the regulation of various physiological activities and diseases, including those related to the central nervous system, cardiovascular system, kidney, and cancer. As a nonselective cation channel, TRPC5 mainly controls the influx of extracellular Ca2+ into cells, thereby modulating cellular depolarization and intracellular ion concentration. Inhibition of TRPC5 by small molecules presents a promising approach for the treatment of TRPC5-associated diseases. In this study, we conducted a comprehensive virtual screening of more than 1.5 million molecules from the Chemdiv database (https://www.chemdiv.com) to identify potential inhibitors of hTRPC5, utilizing the published structures and binding sites of hTRPC5 as a basis. Lipinski's rule, Veber's rule, PAINS filters, pharmacophore analysis, molecular docking, ADMET evaluation and cluster analysis methods were applied for the screening. From this rigorous screening process, 18 candidates exhibiting higher affinities to hTRPC5 were subsequently evaluated for their inhibitory effects on Ca2+ influx using a fluorescence-based assay. Notably, two molecules, namely SML-1 and SML-13, demonstrated significant inhibition of intracellular Ca2+ levels in hTRPC5-overexpressing HEK 293T cells, with IC50 values of 10.2 μM and 10.3 μM, respectively. These findings highlight SML-1 and SML-13 as potential lead molecules for the development of therapeutics targeting hTRPC5 and its associated physiological activities and diseases.
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Affiliation(s)
- Meiling Shen
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Lingfeng Li
- Key Laboratory of Medicinal Chemistry for Natural Resource (Ministry of Education), School of Pharmacy, Yunnan University, Kunming 650091, China
| | - Yue Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Xi Gu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Longhui Bai
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Chengfeng Xia
- Key Laboratory of Medicinal Chemistry for Natural Resource (Ministry of Education), School of Pharmacy, Yunnan University, Kunming 650091, China
| | - Wenyong Xiong
- Key Laboratory of Medicinal Chemistry for Natural Resource (Ministry of Education), School of Pharmacy, Yunnan University, Kunming 650091, China.
| | - Zhili Zuo
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
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Kumar J, Popescu GK, Gantz SC. GluD receptors are functional ion channels. Biophys J 2023; 122:2383-2395. [PMID: 37177782 PMCID: PMC10323023 DOI: 10.1016/j.bpj.2023.05.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/27/2023] [Accepted: 05/09/2023] [Indexed: 05/15/2023] Open
Abstract
In this article, we review contemporary evidence that GluD receptors are functional ion channels whose depolarizing currents contribute to their biological functions, akin to all other members of the ionotropic glutamate receptor (iGluR) family.
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Affiliation(s)
- Janesh Kumar
- Laboratory of Membrane Protein Biology, Council of Scientific and Industrial Research (CSIR)-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Gabriela K Popescu
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, SUNY, Buffalo, New York
| | - Stephanie C Gantz
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, Iowa; Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa.
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Cohen CF, Roh J, Lee SH, Park CK, Berta T. Targeting Nociceptive Neurons and Transient Receptor Potential Channels for the Treatment of Migraine. Int J Mol Sci 2023; 24:ijms24097897. [PMID: 37175602 PMCID: PMC10177956 DOI: 10.3390/ijms24097897] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 04/22/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Migraine is a neurovascular disorder that affects approximately 12% of the global population. While its exact causes are still being studied, researchers believe that nociceptive neurons in the trigeminal ganglia play a key role in the pain signals of migraine. These nociceptive neurons innervate the intracranial meninges and convey pain signals from the meninges to the thalamus. Targeting nociceptive neurons is considered promising due to their accessibility and distinct molecular profile, which includes the expression of several transient receptor potential (TRP) channels. These channels have been linked to various pain conditions, including migraine. This review discusses the role and mechanisms of nociceptive neurons in migraine, the challenges of current anti-migraine drugs, and the evidence for well-studied and emerging TRP channels, particularly TRPC4, as novel targets for migraine prevention and treatment.
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Affiliation(s)
- Cinder Faith Cohen
- Pain Research Center, Department of Anesthesiology, Medical Center, University of Cincinnati, Cincinnati, OH 45219, USA
- Neuroscience Graduate Program, College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Jueun Roh
- Pain Research Center, Department of Anesthesiology, Medical Center, University of Cincinnati, Cincinnati, OH 45219, USA
- Department of Physiology, Gachon Pain Center, College of Medicine, Gachon University, Incheon 21936, Republic of Korea
| | - Sang Hoon Lee
- Pain Research Center, Department of Anesthesiology, Medical Center, University of Cincinnati, Cincinnati, OH 45219, USA
- Neuroscience Graduate Program, College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Chul-Kyu Park
- Department of Physiology, Gachon Pain Center, College of Medicine, Gachon University, Incheon 21936, Republic of Korea
| | - Temugin Berta
- Pain Research Center, Department of Anesthesiology, Medical Center, University of Cincinnati, Cincinnati, OH 45219, USA
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Kytikova OY, Denisenko YK, Novgorodtseva TP, Kovalenko IS. Cannabinoids And Cannabinoid-Like Compounds: Biochemical Characterization And Pharmacological Perspectives. RUSSIAN OPEN MEDICAL JOURNAL 2023. [DOI: 10.15275/rusomj.2023.0107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023] Open
Abstract
Publication interest in cannabinoids, including phytocannabinoids, endogenous cannabinoids, synthetic cannabinoids and cannabinomimetic compounds, is due to the therapeutic potential of these compounds in inflammatory pathology. Since recent years, scientific interest was focused on compounds with cannabinomimetic activity. The therapeutic use of phytocannabinoids and endocannabinoids is somewhat limited due to unresolved issues of dosing, toxicity and safety in humans, while cannabinoid-like compounds combine similar therapeutic effects with a high confirmed safety. Targets for endocannabinoids and phytocannabinoids are endocannabinoid receptors 1 and 2, G protein-coupled receptors (GPCRs), peroxisome proliferator-activated receptors (PPARs), and transient receptor potential ion channels (TRPs). Non-endocannabinoid N-acylethanolamines do not interact with cannabinoid receptors and exhibit agonist activity towards non-cannabinoid receptors, such as PPARs, GPCRs and TRPs. This literature review includes contemporary information on the biological activity, metabolism and pharmacological properties of cannabinoids and cannabinoid-like compounds, as well as their receptors. We established that only a few studies were devoted to the relationship of non-endocannabinoid N-acylethanolamines with non-cannabinoid receptors, such as PPARs, GPCRs, and also with TRPs. We have focused on issues that were insufficiently covered in the published sources in order to identify gaps in existing knowledge and determine the prospects for scientific research.
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Ko J, Kim J, Myeong J, Kwak M, So I. Negative self-regulation of transient receptor potential canonical 4 by the specific interaction with phospholipase C-δ1. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2023; 27:187-196. [PMID: 36815258 PMCID: PMC9968946 DOI: 10.4196/kjpp.2023.27.2.187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 12/27/2022] [Accepted: 12/29/2022] [Indexed: 02/24/2023]
Abstract
Transient receptor potential canonical (TRPC) channels are non-selective calcium-permeable cation channels. It is suggested that TRPC4β is regulated by phospholipase C (PLC) signaling and is especially maintained by phosphatidylinositol 4,5-bisphosphate (PIP2). In this study, we present the regulation mechanism of the TRPC4 channel with PIP2 hydrolysis which is mediated by a channel-bound PLCδ1 but not by the GqPCR signaling pathway. Our electrophysiological recordings demonstrate that the Ca2+ via an open TRPC4 channel activates PLCδ1 in the physiological range, and it causes the decrease of current amplitude. The existence of PLCδ1 accelerated PIP2 depletion when the channel was activated by an agonist. Interestingly, PLCδ1 mutants which have lost the ability to regulate PIP2 level failed to reduce the TRPC4 current amplitude. Our results demonstrate that TRPC4 self-regulates its activity by allowing Ca2+ ions into the cell and promoting the PIP2 hydrolyzing activity of PLCδ1.
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Affiliation(s)
- Juyeon Ko
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jinhyeong Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jongyun Myeong
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Misun Kwak
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Insuk So
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea,Correspondence Insuk So, E-mail:
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Davies A, Tomas A. Appreciating the potential for GPCR crosstalk with ion channels. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 195:101-120. [PMID: 36707150 DOI: 10.1016/bs.pmbts.2022.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
G protein-coupled receptors (GPCRs) are expressed by most tissues in the body and are exploited pharmacologically in a variety of pathological conditions including diabetes, cardiovascular disease, neurological diseases, and cancers. Numerous cell signaling pathways can be regulated by GPCR activation, depending on the specific GPCR, ligand and cell type. Ion channels are among the many effector proteins downstream of these signaling pathways. Saliently, ion channels are also recognized as druggable targets, and there is evidence that their activity may regulate GPCR function via membrane potential and cytoplasmic ion concentration. Overall, there appears to be a large potential for crosstalk between ion channels and GPCRs. This might have implications not only for targeting GPCRs for drug development, but also opens the possibility of co-targeting them with ion channels to achieve improved therapeutic outcomes. In this review, we highlight the large variety of possible GPCR-ion channel crosstalk modes.
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Affiliation(s)
- Amy Davies
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom.
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Ojha NK, Zufall F, Leinders-Zufall T. Optical Activation of Photoswitchable TRPC Ligands in the Mammalian Olfactory System Using Laser Scanning Confocal Microscopy. Methods Mol Biol 2023; 2710:31-47. [PMID: 37688722 DOI: 10.1007/978-1-0716-3425-7_3] [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] [Indexed: 09/11/2023]
Abstract
The transient receptor potential canonical (TRPC) ion channels play important biological roles, but their activation mechanisms are incompletely understood. Here, we describe recent methodological advances using small molecular probes designed for photopharmacology of TRPC channels by focusing on results obtained from the mouse olfactory system. These studies developed and used photoswitchable diacylglycerol (DAG) analogs for ultrarapid activation of native TRPC2 channels in vomeronasal sensory neurons and type B cells of the main olfactory epithelium. Further studies investigated the role of TRPC5 channels in prolactin regulation of dopamine neurons in the arcuate nucleus of the hypothalamus. Here, the first photoswitchable TRPC5 modulator, BTDAzo, was developed and shown to control endogenous TRPC5-based neuronal Ca2+ responses in mouse brain slices. Thus, photoswitchable reagents are rapidly gaining widespread recognition for investigating various types of TRPC channels including TRPC2, TRPC3, TRPC5, and TRPC6, enabling to gain new insights into the gating mechanisms and functions of these channels.
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Affiliation(s)
- Navin K Ojha
- Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
| | - Frank Zufall
- Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany.
| | - Trese Leinders-Zufall
- Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany.
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Manning D, Barrett-Jolley R, Evans RL, Dart C. TRPC1 channel clustering during store-operated Ca 2+ entry in keratinocytes. Front Physiol 2023; 14:1141006. [PMID: 36950299 PMCID: PMC10025536 DOI: 10.3389/fphys.2023.1141006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 02/20/2023] [Indexed: 03/08/2023] Open
Abstract
Skin is the largest organ in the human body with ∼95% of its surface made up of keratinocytes. These cells maintain a healthy skin barrier through regulated differentiation driven by Ca2+-transcriptional coupling. Many important skin conditions arise from disruption of this process although not all stages are fully understood. We know that elevated extracellular Ca2+ at the skin surface is detected by keratinocyte Gαq-coupled receptors that signal to empty endoplasmic reticulum Ca2+ stores. Orai channel store-operated Ca2+ entry (SOCE) and Ca2+ influx via "canonical" transient receptor potential (TRPC)-composed channels then activates transcription factors that drive differentiation. While STIM-mediated activation of Orai channels following store depletion is well defined, how TRPC channels are activated is less clear. Multiple modes of TRPC channel activation have been proposed, including 1) independent TRPC activation by STIM, 2) formation of Orai-TRPC-STIM complexes, and 3) the insertion of constitutively-active TRPC channels into the membrane during SOCE. To help distinguish between these models, we used high-resolution microscopy of intact keratinocyte (HaCaT) cells and immunogold transmission electron microscopy (TEM) of HaCaT plasma membrane sheets. Our data shows no evidence of significant insertion of Orai1 or TRPC subunits into the membrane during SOCE. Analysis of transmission electron microscopy data shows that during store-depletion and SOCE, Orai1 and TRPC subunits form separate membrane-localized clusters that migrate towards each other. This clustering of TRPC channel subunits in keratinocytes may support the formation of TRPC-STIM interactions at ER-plasma membrane junctions that are distinct from Orai-STIM junctions.
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Affiliation(s)
- Declan Manning
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Richard Barrett-Jolley
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Richard L. Evans
- Unilever Research & Development, Port Sunlight Laboratory, Wirral, United Kingdom
| | - Caroline Dart
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
- *Correspondence: Caroline Dart,
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Staruschenko A, Ma R, Palygin O, Dryer SE. Ion channels and channelopathies in glomeruli. Physiol Rev 2023; 103:787-854. [PMID: 36007181 PMCID: PMC9662803 DOI: 10.1152/physrev.00013.2022] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/15/2022] [Accepted: 08/21/2022] [Indexed: 11/22/2022] Open
Abstract
An essential step in renal function entails the formation of an ultrafiltrate that is delivered to the renal tubules for subsequent processing. This process, known as glomerular filtration, is controlled by intrinsic regulatory systems and by paracrine, neuronal, and endocrine signals that converge onto glomerular cells. In addition, the characteristics of glomerular fluid flow, such as the glomerular filtration rate and the glomerular filtration fraction, play an important role in determining blood flow to the rest of the kidney. Consequently, disease processes that initially affect glomeruli are the most likely to lead to end-stage kidney failure. The cells that comprise the glomerular filter, especially podocytes and mesangial cells, express many different types of ion channels that regulate intrinsic aspects of cell function and cellular responses to the local environment, such as changes in glomerular capillary pressure. Dysregulation of glomerular ion channels, such as changes in TRPC6, can lead to devastating glomerular diseases, and a number of channels, including TRPC6, TRPC5, and various ionotropic receptors, are promising targets for drug development. This review discusses glomerular structure and glomerular disease processes. It also describes the types of plasma membrane ion channels that have been identified in glomerular cells, the physiological and pathophysiological contexts in which they operate, and the pathways by which they are regulated and dysregulated. The contributions of these channels to glomerular disease processes, such as focal segmental glomerulosclerosis (FSGS) and diabetic nephropathy, as well as the development of drugs that target these channels are also discussed.
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Affiliation(s)
- Alexander Staruschenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
- Hypertension and Kidney Research Center, University of South Florida, Tampa, Florida
- James A. Haley Veterans Hospital, Tampa, Florida
| | - Rong Ma
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Oleg Palygin
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
- Department of Biomedical Sciences, Tilman J. Fertitta Family College of Medicine, University of Houston, Houston, Texas
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Heckman CA, Ademuyiwa OM, Cayer ML. How filopodia respond to calcium in the absence of a calcium-binding structural protein: non-channel functions of TRP. Cell Commun Signal 2022; 20:130. [PMID: 36028898 PMCID: PMC9414478 DOI: 10.1186/s12964-022-00927-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 06/21/2022] [Indexed: 11/18/2022] Open
Abstract
Background For many cell types, directional locomotion depends on their maintaining filopodia at the leading edge. Filopodia lack any Ca2+-binding structural protein but respond to store-operated Ca2+ entry (SOCE). Methods SOCE was induced by first replacing the medium with Ca2+-free salt solution with cyclopiazonic acid (CPA). This lowers Ca2+ in the ER and causes stromal interacting molecule (STIM) to be translocated to the cell surface. After this priming step, CPA was washed out, and Ca2+ influx restored by addition of extracellular Ca2+. Intracellular Ca2+ levels were measured by calcium orange fluorescence. Regulatory mechanisms were identified by pharmacological treatments. Proteins mediating SOCE were localized by immunofluorescence and analyzed after image processing. Results Depletion of the ER Ca2+ increased filopodia prevalence briefly, followed by a spontaneous decline that was blocked by inhibitors of endocytosis. Intracellular Ca2+ increased continuously for ~ 50 min. STIM and a transient receptor potential canonical (TRPC) protein were found in separate compartments, but an aquaporin unrelated to SOCE was present in both. STIM1- and TRPC1-bearing vesicles were trafficked on microtubules. During depletion, STIM1 migrated to the surface where it coincided with Orai in punctae, as expected. TRPC1 was partially colocalized with Vamp2, a rapidly releasable pool marker, and with phospholipases (PLCs). TRPC1 retreated to internal compartments during ER depletion. Replenishment of extracellular Ca2+ altered the STIM1 distribution, which came to resemble that of untreated cells. Vamp2 and TRPC1 underwent exocytosis and became homogeneously distributed on the cell surface. This was accompanied by an increased prevalence of filopodia, which was blocked by inhibitors of TRPC1/4/5 and endocytosis. Conclusions Because the media were devoid of ligands that activate receptors during depletion and Ca2+ replenishment, we could attribute filopodia extension to SOCE. We propose that the Orai current stimulates exocytosis of TRPC-bearing vesicles, and that Ca2+ influx through TRPC inhibits PLC activity. This allows regeneration of the substrate, phosphatidylinositol 4,5 bisphosphate (PIP2), a platform for assembling proteins, e. g. Enabled and IRSp53. TRPC contact with PLC is required but is broken by TRPC dissemination. This explains how STIM1 regulates the cell’s ability to orient itself in response to attractive or repulsive cues. Video Abstract
Supplementary Information The online version contains supplementary material available at 10.1186/s12964-022-00927-y.
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Affiliation(s)
- C A Heckman
- Department of Biological Sciences, 217 Life Science Building, Bowling Green State University, Bowling Green, OH, 43403-0001, USA.
| | - O M Ademuyiwa
- Department of Biological Sciences, 217 Life Science Building, Bowling Green State University, Bowling Green, OH, 43403-0001, USA
| | - M L Cayer
- Center for Microscopy and Microanalysis, Bowling Green State University, Bowling Green, OH, 43403, USA
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14
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Zimova L, Ptakova A, Mitro M, Krusek J, Vlachova V. Activity dependent inhibition of TRPC1/4/5 channels by duloxetine involves voltage sensor-like domain. Biomed Pharmacother 2022; 152:113262. [PMID: 35691156 DOI: 10.1016/j.biopha.2022.113262] [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: 04/20/2022] [Revised: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 11/18/2022] Open
Abstract
Transient receptor potential canonical 5 (TRPC5) is a polymodal, calcium-permeable, nonselective ion channel that is expressed in the brain and 75 % of human sensory neurons. Its pharmacological or genetic inhibition leads to the relief of neuropathic and inflammatory pain. The clinically approved drug duloxetine is superior to other serotonin and norepinephrine reuptake inhibitors at managing painful neuropathies, but it is not known why. Here we ask whether the TRPC5 receptor is modulated by duloxetine and may contribute to its analgesic effect. Electrophysiological measurements of heterologously expressed human TRPC5 in HEK293T cells were performed to evaluate the effect of duloxetine. The interaction site was identified by molecular docking and molecular dynamics simulations in combination with point mutagenesis. We found that duloxetine inhibits TRPC5 in a concentration-dependent manner with a high potency (IC50 = 0.54 ± 0.03 µM). Our data suggest that duloxetine binds into a voltage sensor-like domain. For the interaction, Glu418 exhibited particular importance due to putative hydrogen bond formation. Duloxetine effectively inhibits TRPC5 currents induced by cooling, voltage, direct agonists and by the stimulation of the PLC pathway. The finding that this TRPC5 inhibitor is widely used and well tolerated provides a scaffold for new pain treatment strategies.
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Affiliation(s)
- Lucie Zimova
- Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
| | - Alexandra Ptakova
- Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic; Faculty of Science, Charles University in Prague, Prague, Czech Republic.
| | - Michal Mitro
- Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic; Faculty of Science, Charles University in Prague, Prague, Czech Republic.
| | - Jan Krusek
- Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
| | - Viktorie Vlachova
- Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
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15
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Erkan‐Candag H, Clarke A, Tiapko O, Gsell MAF, Stockner T, Groschner K. Diacylglycerols interact with the L2 lipidation site in TRPC3 to induce a sensitized channel state. EMBO Rep 2022; 23:e54276. [PMID: 35604352 PMCID: PMC9253791 DOI: 10.15252/embr.202154276] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 04/11/2022] [Accepted: 04/25/2022] [Indexed: 11/09/2022] Open
Abstract
Coordination of lipids within transient receptor potential canonical channels (TRPCs) is essential for their Ca2+ signaling function. Single particle cryo-EM studies identified two lipid interaction sites, designated L1 and L2, which are proposed to accommodate diacylglycerols (DAGs). To explore the role of L1 and L2 in TRPC3 function, we combined structure-guided mutagenesis and electrophysiological recording with molecular dynamics (MD) simulations. MD simulations indicate rapid DAG accumulation within both L1 and L2 upon its availability within the plasma membrane. Electrophysiological experiments using a photoswitchable DAG-probe reveal potentiation of TRPC3 currents during repetitive activation by DAG. Importantly, initial DAG exposure generates a subsequently sensitized channel state that is associated with significantly faster activation kinetics. TRPC3 sensitization is specifically promoted by mutations within L2, with G652A exhibiting sensitization at very low levels of active DAG. We demonstrate the ability of TRPC3 to adopt a closed state conformation that features partial lipidation of L2 sites by DAG and enables fast activation of the channel by the phospholipase C-DAG pathway.
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Affiliation(s)
- Hazel Erkan‐Candag
- Gottfried‐Schatz‐Research‐Center – BiophysicsMedical University of GrazGrazAustria
| | - Amy Clarke
- Institute of PharmacologyMedical University of ViennaViennaAustria
| | - Oleksandra Tiapko
- Gottfried‐Schatz‐Research‐Center – BiophysicsMedical University of GrazGrazAustria
| | - Mathias AF Gsell
- Gottfried‐Schatz‐Research‐Center – BiophysicsMedical University of GrazGrazAustria
| | - Thomas Stockner
- Institute of PharmacologyMedical University of ViennaViennaAustria
| | - Klaus Groschner
- Gottfried‐Schatz‐Research‐Center – BiophysicsMedical University of GrazGrazAustria
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16
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Ptakova A, Mitro M, Zimova L, Vlachova V. Cellular context determines primary characteristics of human TRPC5 as a cold-activated channel. J Cell Physiol 2022; 237:3614-3626. [PMID: 35762104 DOI: 10.1002/jcp.30821] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/23/2022] [Accepted: 06/17/2022] [Indexed: 11/11/2022]
Abstract
The human transient receptor potential canonical 5 (TRPC5) is a calcium-permeable, nonselective cation channel expressed in the central and peripheral nervous system and also in other tissues such as the kidney, synovium, and odontoblasts. TRPC5 has been recently confirmed to play a key role in spontaneous, inflammatory mechanical, and cold pain. Although TRPC5 activation is known to be cold sensitive, it is unclear whether this property is intrinsic to the channel protein and whether or to what extent it may be determined by the cellular environment. In this study, we explored the cold sensitivity of human TRPC5 at the single-channel level using transiently transfected HEK293T cells. Upon decreasing the temperature, the channel demonstrated prolonged mean open dwell times and a robust increase in the open probability (Po ), whereas the amplitude of unitary currents decreased ~1.5-fold per 10°C of temperature difference. In the absence of any agonists, the temperature dependence of Po was sigmoidal, with a steep slope within the temperature range of 16°C-11°C, and exhibited saturation below 8-5°C. Thermodynamic analysis revealed significant changes in enthalpy and entropy, suggesting that substantial conformational changes accompany cold-induced gating. The mutant channel T970A, in which the regulation downstream of G-protein coupled receptor signaling was abrogated, exhibited higher basal activity at room temperature and a less steep temperature response profile, with an apparent threshold below 22°C. An even more pronounced decrease in the activation threshold was observed in a mutant that disrupted the electrostatic interaction of TRPC5 with the endoplasmic reticulum calcium sensor stromal interaction molecule 1. Thus, TRPC5 exhibits features of an intrinsically cold-gated channel; its sensitivity to cold tightly depends on the phosphorylation status of the protein and intracellular calcium homeostasis.
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Affiliation(s)
- Alexandra Ptakova
- Department of Cellular Neurophysiology, Institute of Physiology Czech Academy of Sciences, Prague, Czech Republic.,Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Michal Mitro
- Department of Cellular Neurophysiology, Institute of Physiology Czech Academy of Sciences, Prague, Czech Republic.,Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Lucie Zimova
- Department of Cellular Neurophysiology, Institute of Physiology Czech Academy of Sciences, Prague, Czech Republic
| | - Viktorie Vlachova
- Department of Cellular Neurophysiology, Institute of Physiology Czech Academy of Sciences, Prague, Czech Republic
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17
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PKC regulation of ion channels: The involvement of PIP 2. J Biol Chem 2022; 298:102035. [PMID: 35588786 PMCID: PMC9198471 DOI: 10.1016/j.jbc.2022.102035] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 11/24/2022] Open
Abstract
Ion channels are integral membrane proteins whose gating has been increasingly shown to depend on the presence of the low-abundance membrane phospholipid, phosphatidylinositol (4,5) bisphosphate. The expression and function of ion channels is tightly regulated via protein phosphorylation by specific kinases, including various PKC isoforms. Several channels have further been shown to be regulated by PKC through altered surface expression, probability of channel opening, shifts in voltage dependence of their activation, or changes in inactivation or desensitization. In this review, we survey the impact of phosphorylation of various ion channels by PKC isoforms and examine the dependence of phosphorylated ion channels on phosphatidylinositol (4,5) bisphosphate as a mechanistic endpoint to control channel gating.
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18
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Liu H, Lin WY, Leibow SR, Morateck AJ, Ahuja M, Muallem S. TRPC3 channel gating by lipids requires localization at the ER/PM junctions defined by STIM1. J Biophys Biochem Cytol 2022; 221:213134. [PMID: 35416932 PMCID: PMC9011324 DOI: 10.1083/jcb.202107120] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 12/08/2021] [Accepted: 03/08/2022] [Indexed: 12/21/2022] Open
Abstract
TRPC3, a member of the transient receptor potential (TRP) superfamily of cation channels, is a lipid-regulated, Ca2+-permeable channel that mediates essential components of the receptor evoked Ca2+ signal. The modes and mechanisms by which lipids regulate TRPC3 and other members of the TRPC channel family are not well understood. Here, we report that PI(4,5)P2 regulates TRPC3 in three independent modes. PLC-dependent hydrolysis generates diacylglycerol (DAG) that interacts with lipid-binding site 2 in the channel pore. PI(4,5)P2 interacts with lipid site 1 to inhibit TRPC3 opening and regulate access of DAG to the pore lipid site 2. PI(4,5)P2 is required for regulating pore ionic selectivity by receptor stimulation. Notably, the activation and regulation of TRPC3 by PI(4,5)P2 require recruitment of TRPC3 to the ER/PM junctions at a PI(4,5)P2-rich domain. Accordingly, we identified an FFAT site at the TRPC3 N-terminal loop within the linker helices that envelope the C-terminus pole helix. The FFAT site interacts with the ER-resident VAPB to recruit TRPC3 to the ER/PM junctions and control its receptor-mediated activation. The TRPC3’s lipid interacting sites are fully conserved in TRPC6 and TRPC7 and in part in other TRPC channels. These findings inform on multiple modes of regulation of ion channels by lipids that may be relevant to diseases affected by aberrant TRPC channel functions.
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Affiliation(s)
- Haiping Liu
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
| | - Wei-Yin Lin
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
| | - Spencer R Leibow
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
| | - Alexander J Morateck
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
| | - Malini Ahuja
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
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19
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Hermann C, Treder A, Näher M, Geiseler R, Gudermann T, Mederos Y Schnitzler M, Storch U. The normalized slope conductance as a tool for quantitative analysis of current-voltage relations. Biophys J 2022; 121:1435-1448. [PMID: 35300969 PMCID: PMC9072577 DOI: 10.1016/j.bpj.2022.03.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 12/02/2021] [Accepted: 03/11/2022] [Indexed: 11/29/2022] Open
Abstract
The patch-clamp method which was rewarded with the Nobel Prize in 1991 is a well-established and indispensable method to study ion channels in living cells and to biophysically characterize non-voltage-gated ion channels that comprise about 70% of all ion channels in the human genome. To investigate the biophysical properties of non-voltage-gated ion channels, whole-cell measurements with application of continuous voltage-ramps are routinely conducted to obtain current-voltage (IV) relationships. However, adequate tools for detailed and quantitative analysis of IV curves are still missing. We use the example of the transient receptor potential classical (TRPC) channel family to elucidate whether the normalized slope conductance (NSC) is an appropriate tool for a reliable discrimination of the IV curves of diverse TRPC channels that differ in their individual curve progression. We provide a robust calculation method for the NSC, and by applying this method we find that TRPC channel activators and modulators can evoke different NSC progressions independent from their expression levels which is pointing to distinguishable active channel states. TRPC6 mutations of patients suffering from focal segmental glomerulosclerosis (FSGS) resulted in distinct NSC progressions suggesting that the NSC is suitable to investigate structure-function relations and might help unravel the unknown pathomechanisms leading to FSGS. Altogether, the NCS represents an effective algorithm for extended biophysical characterization of non-voltage-gated ion channels.
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Affiliation(s)
- Christian Hermann
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany
| | - Aaron Treder
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany
| | - Marius Näher
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany
| | - Roman Geiseler
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany;; Comprehensive Pneumology Center Munich (CPC-M), German Center for Lung Research, Munich, Germany
| | - Michael Mederos Y Schnitzler
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany;; DZHK (German Centre for Cardiovascular Research), Munich Heart Alliance, Munich, Germany.
| | - Ursula Storch
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany;; Institute for Cardiovascular Prevention (IPEK), Ludwig Maximilian University of Munich, 80336 Munich, Germany.
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20
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Bon RS, Wright DJ, Beech DJ, Sukumar P. Pharmacology of TRPC Channels and Its Potential in Cardiovascular and Metabolic Medicine. Annu Rev Pharmacol Toxicol 2022; 62:427-446. [PMID: 34499525 DOI: 10.1146/annurev-pharmtox-030121-122314] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Transient receptor potential canonical (TRPC) proteins assemble to form homo- or heterotetrameric, nonselective cation channels permeable to K+, Na+, and Ca2+. TRPC channels are thought to act as complex integrators of physical and chemical environmental stimuli. Although the understanding of essential physiological roles of TRPC channels is incomplete, their implication in various pathological mechanisms and conditions of the nervous system, kidneys, and cardiovascular system in combination with the lack of major adverse effects of TRPC knockout or TRPC channel inhibition is driving the search of TRPC channel modulators as potential therapeutics. Here, we review the most promising small-molecule TRPC channel modulators, the understanding of their mode of action, and their potential in the study and treatment of cardiovascular and metabolic disease.
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Affiliation(s)
- Robin S Bon
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom;
| | - David J Wright
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom;
| | - David J Beech
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom;
| | - Piruthivi Sukumar
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom;
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21
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Zhao Y, McVeigh BM, Moiseenkova-Bell VY. Structural Pharmacology of TRP Channels. J Mol Biol 2021; 433:166914. [PMID: 33676926 PMCID: PMC8338738 DOI: 10.1016/j.jmb.2021.166914] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 12/15/2022]
Abstract
Transient receptor potential (TRP) ion channels are a super-family of ion channels that mediate transmembrane cation flux with polymodal activation, ranging from chemical to physical stimuli. Furthermore, due to their ubiquitous expression and role in human diseases, they serve as potential pharmacological targets. Advances in cryo-EM TRP channel structural biology has revealed general, as well as diverse, architectural elements and regulatory sites among TRP channel subfamilies. Here, we review the endogenous and pharmacological ligand-binding sites of TRP channels and their regulatory mechanisms.
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Affiliation(s)
- Yaxian Zhao
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bridget M McVeigh
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Vera Y Moiseenkova-Bell
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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22
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Faria J, Gerritsen KGF, Nguyen TQ, Mihaila SM, Masereeuw R. Diabetic proximal tubulopathy: Can we mimic the disease for in vitro screening of SGLT inhibitors? Eur J Pharmacol 2021; 908:174378. [PMID: 34303664 DOI: 10.1016/j.ejphar.2021.174378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/15/2021] [Accepted: 07/21/2021] [Indexed: 11/27/2022]
Abstract
Diabetic kidney disease (DKD) is the foremost cause of renal failure. While the glomeruli are severely affected in the course of the disease, the main determinant for disease progression is the tubulointerstitial compartment. DKD does not develop in the absence of hyperglycemia. Since the proximal tubule is the major player in glucose reabsorption, it has been widely studied as a therapeutic target for the development of new therapies. Currently, there are several proximal tubule cell lines available, being the human kidney-2 (HK-2) and human kidney clone-8 (HKC-8) cell lines the ones widely used for studying mechanisms of DKD. Studies in these models have pushed forward the understanding on how DKD unravels, however, these cell culture models possess limitations that hamper research, including lack of transporters and dedifferentiation. The sodium-glucose cotransporters (SGLT) are identified as key players in glucose reabsorption and pharmacological inhibitors have shown to be beneficial for the long-term clinical outcome in DKD. However, their mechanism of action has, as of yet, not been fully elucidated. To comprehend the protective effects of SGLT inhibitors, it is essential to understand the complete functional, structural, and molecular features of the disease, which until now have been difficult to recapitulate. This review addresses the molecular events of diabetic proximal tubulopathy. In addition, we evaluate the protective role of SGLT inhibitors in cardiovascular and renal outcomes, and provide an overview of various in vitro models mimicking diabetic proximal tubulopathy used so far. Finally, new insights on advanced in vitro systems to surpass past limitations are postulated.
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Affiliation(s)
- João Faria
- Div. Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, the Netherlands
| | - Karin G F Gerritsen
- Dept. Nephrology and Hypertension, University Medical Center Utrecht, the Netherlands
| | - Tri Q Nguyen
- Dept. Pathology, University Medical Center Utrecht, the Netherlands
| | - Silvia M Mihaila
- Div. Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, the Netherlands; Dept. Nephrology and Hypertension, University Medical Center Utrecht, the Netherlands
| | - Rosalinde Masereeuw
- Div. Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, the Netherlands.
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23
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Leinders-Zufall T, Storch U, Mederos y Schnitzler M, Ojha NK, Koike K, Gudermann T, Zufall F. A diacylglycerol photoswitching protocol for studying TRPC channel functions in mammalian cells and tissue slices. STAR Protoc 2021; 2:100527. [PMID: 34027485 PMCID: PMC8121987 DOI: 10.1016/j.xpro.2021.100527] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Small molecular probes designed for photopharmacology and opto-chemogenetics are rapidly gaining widespread recognition for investigations of transient receptor potential canonical (TRPC) channels. This protocol describes the use of three photoswitchable diacylglycerol analogs—PhoDAG-1, PhoDAG-3, and OptoDArG—for ultrarapid activation and deactivation of native TRPC2 channels in mouse vomeronasal sensory neurons and olfactory type B cells, as well as heterologously expressed human TRPC6 channels. Photoconversion can be achieved in mammalian tissue slices and enables all-optical stimulation and shutoff of TRPC channels. For complete details on the use and execution of this protocol, please refer to Leinders-Zufall et al. (2018). DAG photoswitching enables ultrarapid activation and deactivation of TRPC channels Multiple photoswitchable DAG analogs are now available DAG photoconversion is sufficient for the gating of TRPC2, TRPC3, and TRPC6 Photoswitching combined with Ca2+ imaging enables all-optical stimulation and recording
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Affiliation(s)
- Trese Leinders-Zufall
- Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Germany
| | - Ursula Storch
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 München, Germany
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-Universität München, 80336 München, Germany
| | - Michael Mederos y Schnitzler
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 München, Germany
| | - Navin K. Ojha
- Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Germany
| | - Kohei Koike
- Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Germany
| | - Thomas Gudermann
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 München, Germany
| | - Frank Zufall
- Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Germany
- Corresponding author
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24
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Ningoo M, Plant LD, Greka A, Logothetis DE. PIP 2 regulation of TRPC5 channel activation and desensitization. J Biol Chem 2021; 296:100726. [PMID: 33933453 PMCID: PMC8191310 DOI: 10.1016/j.jbc.2021.100726] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 04/20/2021] [Accepted: 04/28/2021] [Indexed: 10/27/2022] Open
Abstract
Transient receptor potential canonical type 5 (TRPC5) ion channels are expressed in the brain and kidney and have been identified as promising therapeutic targets whose selective inhibition can protect against diseases driven by a leaky kidney filter, such as focal segmental glomerular sclerosis. TRPC5 channels are activated not only by elevated levels of extracellular Ca2+or lanthanide ions but also by G protein (Gq/11) stimulation. Phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis by phospholipase C enzymes leads to PKC-mediated phosphorylation of TRPC5 channels and their subsequent desensitization. However, the roles of PIP2 in activation and maintenance of TRPC5 channel activity via its hydrolysis product diacyl glycerol (DAG), as well as the mechanism of desensitization of TRPC5 activity by DAG-stimulated PKC activity, remain unclear. Here, we designed experiments to distinguish between the processes underlying channel activation and inhibition. Employing whole-cell patch-clamp, we used an optogenetic tool to dephosphorylate PIP2 and assess channel-PIP2 interactions influenced by activators, such as DAG, or inhibitors, such as PKC phosphorylation. Using total internal reflection microscopy, we assessed channel cell surface density. We show that PIP2 controls both the PKC-mediated inhibition and the DAG- and lanthanide-mediated activation of TRPC5 currents via control of gating rather than channel cell surface density. These mechanistic insights promise to aid in the development of more selective and precise inhibitors to block TRPC5 channel activity and illuminate new opportunities for targeted therapies for a group of chronic kidney diseases for which there is currently a great unmet need.
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Affiliation(s)
- Mehek Ningoo
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts, USA
| | - Leigh D Plant
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts, USA; Center for Drug Discovery, Northeastern University, Boston, Massachusetts, USA
| | - Anna Greka
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA; Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Diomedes E Logothetis
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts, USA; Center for Drug Discovery, Northeastern University, Boston, Massachusetts, USA; Department of Chemistry and Chemical Biology, College of Science, Northeastern University, Boston, Massachusetts, USA.
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25
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Storch U, Mederos Y Schnitzler M, Gudermann T. A greasy business: Identification of a diacylglycerol binding site in human TRPC5 channels by cryo-EM. Cell Calcium 2021; 97:102414. [PMID: 33930818 DOI: 10.1016/j.ceca.2021.102414] [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: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 11/22/2022]
Abstract
The transient receptor potential classical or canonical (TRPC) 5 channel is a non-selective calcium-permeable cation channel that recently emerged as a promising target for the treatment of various diseases such as mental disorders and kidney diseases. Thus, detailed insight into the structural properties of TRPC5 channels is of utmost importance to further advance TRPC5 channels as drug targets. Recently, Song et al. (2021) have presented cryo-EM structures of the human TRPC5 channel alone or in complex with two different inhibitors thereby revealing two new distinct drug binding sites. Moreover, a binding site for the second messenger diacylglycerol (DAG) has been identified commensurate with a key role of DAG for TRPC5 channel activation.
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Affiliation(s)
- Ursula Storch
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336, Munich, Germany; Institute for Cardiovascular Prevention (IPEK), Ludwig Maximilian University of Munich, 80336, Munich, Germany
| | - Michael Mederos Y Schnitzler
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Munich Heart Alliance, Munich, Germany.
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336, Munich, Germany; German Center for Lung Research, Munich, Germany.
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26
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TRPC channel-derived calcium fluxes differentially regulate ATP and flow-induced activation of eNOS. Nitric Oxide 2021; 111-112:1-13. [PMID: 33813098 DOI: 10.1016/j.niox.2021.03.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 03/27/2021] [Indexed: 12/28/2022]
Abstract
Endothelial dysfunction, characterised by impaired nitric oxide (NO) bioavailability, arises in response to a variety of cardiovascular risk factors and precedes atherosclerosis. NO is produced by tight regulation of endothelial nitric oxide synthase (eNOS) activity in response to vasodilatory stimuli. This regulation of eNOS is mediated in part by store-operated calcium entry (SOCE). We hypothesized that both ATP- and flow-induced eNOS activation are regulated by SOCE derived from Orai1 channels and members of the transient receptor potential canonical (TRPC) channel family. Bovine aortic endothelial cells (BAECs) were pre-treated with pharmacological inhibitors of TRPC channels and Orai1 to examine their effect on calcium signaling and eNOS activation in response to flow and ATP. The peak and sustained ATP-induced calcium signal and the resulting eNOS activation were attenuated by inhibition of TRPC3, which we found to be store operated. TRPC4 blockade reduced the transient peak in calcium concentration following ATP stimulation, but did not significantly reduce eNOS activity. Simultaneous TRPC3 & 4 inhibition reduced flow-induced NO production via alterations in phosphorylation-mediated eNOS activity. Inhibition of TRPC1/6 or Orai1 failed to lower ATP-induced calcium entry or eNOS activation. Our results suggest that TRPC3 is a store-operated channel in BAECs and is the key regulator of ATP-induced eNOS activation, whereas flow stimulation also recruits TRPC4 into the pathway for the synthesis of NO.
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27
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Song K, Wei M, Guo W, Quan L, Kang Y, Wu JX, Chen L. Structural basis for human TRPC5 channel inhibition by two distinct inhibitors. eLife 2021; 10:63429. [PMID: 33683200 PMCID: PMC7987348 DOI: 10.7554/elife.63429] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 03/05/2021] [Indexed: 02/06/2023] Open
Abstract
TRPC5 channel is a nonselective cation channel that participates in diverse physiological processes. TRPC5 inhibitors show promise in the treatment of anxiety disorder, depression, and kidney disease. However, the binding sites and inhibitory mechanism of TRPC5 inhibitors remain elusive. Here, we present the cryo-EM structures of human TRPC5 in complex with two distinct inhibitors, namely clemizole and HC-070, to the resolution of 2.7 Å. The structures reveal that clemizole binds inside the voltage sensor-like domain of each subunit. In contrast, HC-070 is wedged between adjacent subunits and replaces the glycerol group of a putative diacylglycerol molecule near the extracellular side. Moreover, we found mutations in the inhibitor binding pockets altered the potency of inhibitors. These structures suggest that both clemizole and HC-070 exert the inhibitory functions by stabilizing the ion channel in a nonconductive closed state. These results pave the way for further design and optimization of inhibitors targeting human TRPC5.
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Affiliation(s)
- Kangcheng Song
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China
| | - Miao Wei
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China
| | - Wenjun Guo
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China
| | - Li Quan
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China
| | - Yunlu Kang
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China
| | - Jing-Xiang Wu
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Lei Chen
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
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28
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Transient Receptor Potential Canonical Channels in Health and Disease: A 2020 Update. Cells 2021; 10:cells10030496. [PMID: 33668918 PMCID: PMC7996490 DOI: 10.3390/cells10030496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 02/21/2021] [Indexed: 11/16/2022] Open
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29
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Jeon J, Bu F, Sun G, Tian JB, Ting SM, Li J, Aronowski J, Birnbaumer L, Freichel M, Zhu MX. Contribution of TRPC Channels in Neuronal Excitotoxicity Associated With Neurodegenerative Disease and Ischemic Stroke. Front Cell Dev Biol 2021; 8:618663. [PMID: 33490083 PMCID: PMC7820370 DOI: 10.3389/fcell.2020.618663] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 12/11/2020] [Indexed: 12/12/2022] Open
Abstract
The seven canonical members of transient receptor potential (TRPC) proteins form cation channels that evoke membrane depolarization and intracellular calcium concentration ([Ca2+] i ) rise, which are not only important for regulating cell function but their deregulation can also lead to cell damage. Recent studies have implicated complex roles of TRPC channels in neurodegenerative diseases including ischemic stroke. Brain ischemia reduces oxygen and glucose supply to neurons, i.e., Oxygen and Glucose Deprivation (OGD), resulting in [Ca2+] i elevation, ion dyshomeostasis, and excitotoxicity, which are also common in many forms of neurodegenerative diseases. Although ionotropic glutamate receptors, e.g., N-methyl-D-aspartate receptors, are well established to play roles in excitotoxicity, the contribution of metabotropic glutamate receptors and their downstream effectors, i.e., TRPC channels, should not be neglected. Here, we summarize the current findings about contributions of TRPC channels in neurodegenerative diseases, with a focus on OGD-induced neuronal death and rodent models of cerebral ischemia/reperfusion. TRPC channels play both detrimental and protective roles to neurodegeneration depending on the TRPC subtype and specific pathological conditions involved. When illustrated the mechanisms by which TRPC channels are involved in neuronal survival or death seem differ greatly, implicating diverse and complex regulation. We provide our own data showing that TRPC1/C4/C5, especially TRPC4, may be generally detrimental in OGD and cerebral ischemia/reperfusion. We propose that although TRPC channels significantly contribute to ischemic neuronal death, detailed mechanisms and specific roles of TRPC subtypes in brain injury at different stages of ischemia/reperfusion and in different brain regions need to be carefully and systematically investigated.
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Affiliation(s)
- Jaepyo Jeon
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Fan Bu
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Guanghua Sun
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Jin-Bin Tian
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Shun-Ming Ting
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Jun Li
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Jaroslaw Aronowski
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Lutz Birnbaumer
- Institute for Biomedical Research (BIOMED UCA-CONICET), Buenos Aires, Argentina.,School of Medical Sciences, Catholic University of Argentina (UCA), Buenos Aires, Argentina.,Neurobiology Laboratory, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Marc Freichel
- Department of Pharmacology, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
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30
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Kammala AK, Syed M, Yang C, Occhiuto CJ, Subramanian H. A Critical Role for Na +/H + Exchanger Regulatory Factor 1 in Modulating FcεRI-Mediated Mast Cell Activation. THE JOURNAL OF IMMUNOLOGY 2020; 206:471-480. [PMID: 33361207 DOI: 10.4049/jimmunol.2000671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 11/23/2020] [Indexed: 01/01/2023]
Abstract
Mast cells are tissue-resident immune cells that play pivotal roles in initiating and amplifying allergic/anaphylactic reactions in humans. Their activation occurs via multiple mechanisms, which include cross-linking of the IgE-bound, high-affinity IgE receptors (FcεRI) by allergens or Ags and the binding of anaphylatoxins such as C3a to its receptor, C3aR. We have previously demonstrated that the Na+/H+ exchanger regulatory factor 1 (NHERF1) promotes C3aR functions in human mast cells. In the current study, we show that NHERF1 regulates mast cell response following FcεRI stimulation. Specifically, intracellular Ca2+ mobilization, activation of the MAPKs (ERK1/2 and P38), and production of cytokines (IL-13 and IL-6) following exposure to IgE/Ag were significantly reduced in mast cells from NHERF1+/‒ mice. In agreement with our in vitro data, mast cell-mediated passive cutaneous anaphylaxis and passive systemic anaphylaxis were reduced in NHERF1+/‒ mice and mast cell-deficient KitW-sh/W-sh mice engrafted with NHERF1+/‒ mast cells. Mechanistically, the levels of microRNAs (miRNAs) that regulate mast cell responses, miRNA 155-3p and miRNA 155-5p, were altered in mast cells from NHERF1+/‒ mice. Moreover, NHERF1 rapidly localized to the nucleus of mast cells following FcεRI stimulation. In summary, our results suggest that the NHERF1 acts as an adapter molecule and promotes IgE/Ag-induced mast cell activation. Further elucidating the mechanisms through which NHERF1 modulates mast cell responses will lend insights into the development of new therapeutic strategies to target mast cells during anaphylaxis or other allergic diseases.
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Affiliation(s)
- Ananth K Kammala
- Department of Physiology, Michigan State University, East Lansing, MI 48824
| | - Meesum Syed
- Department of Physiology, Michigan State University, East Lansing, MI 48824
| | - Canchai Yang
- Department of Physiology, Michigan State University, East Lansing, MI 48824
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31
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Vinayagam D, Quentin D, Yu-Strzelczyk J, Sitsel O, Merino F, Stabrin M, Hofnagel O, Yu M, Ledeboer MW, Nagel G, Malojcic G, Raunser S. Structural basis of TRPC4 regulation by calmodulin and pharmacological agents. eLife 2020; 9:e60603. [PMID: 33236980 PMCID: PMC7735759 DOI: 10.7554/elife.60603] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023] Open
Abstract
Canonical transient receptor potential channels (TRPC) are involved in receptor-operated and/or store-operated Ca2+ signaling. Inhibition of TRPCs by small molecules was shown to be promising in treating renal diseases. In cells, the channels are regulated by calmodulin (CaM). Molecular details of both CaM and drug binding have remained elusive so far. Here, we report structures of TRPC4 in complex with three pyridazinone-based inhibitors and CaM. The structures reveal that all the inhibitors bind to the same cavity of the voltage-sensing-like domain and allow us to describe how structural changes from the ligand-binding site can be transmitted to the central ion-conducting pore of TRPC4. CaM binds to the rib helix of TRPC4, which results in the ordering of a previously disordered region, fixing the channel in its closed conformation. This represents a novel CaM-induced regulatory mechanism of canonical TRP channels.
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Affiliation(s)
| | - Dennis Quentin
- Department of Structural Biochemistry, Max Planck Institute of Molecular PhysiologyDortmundGermany
| | - Jing Yu-Strzelczyk
- Department of Neurophysiology, Physiological Institute, Julius-Maximilians-Universität WürzburgWürzburgGermany
| | - Oleg Sitsel
- Department of Structural Biochemistry, Max Planck Institute of Molecular PhysiologyDortmundGermany
| | - Felipe Merino
- Department of Structural Biochemistry, Max Planck Institute of Molecular PhysiologyDortmundGermany
| | - Markus Stabrin
- Department of Structural Biochemistry, Max Planck Institute of Molecular PhysiologyDortmundGermany
| | - Oliver Hofnagel
- Department of Structural Biochemistry, Max Planck Institute of Molecular PhysiologyDortmundGermany
| | | | | | - Georg Nagel
- Department of Neurophysiology, Physiological Institute, Julius-Maximilians-Universität WürzburgWürzburgGermany
| | | | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular PhysiologyDortmundGermany
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32
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Liu B, Zhang W, Guo S, Zuo Z. Discovery of novel modulators targeting human TRPC5: Docking-based virtual screening, molecular dynamics simulation and binding affinity predication. J Mol Graph Model 2020; 102:107795. [PMID: 33161371 DOI: 10.1016/j.jmgm.2020.107795] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 10/28/2020] [Accepted: 10/28/2020] [Indexed: 11/20/2022]
Abstract
Canonical transient receptor potential channel 5 (TRPC5) plays a key role in the regulation of central nervous system, cardiovascular system, kidney disease, cancer, and could be also involved in liver function, arthritis, diabetes-associated complications and so on. However, evidence of TRPC5 function on cellular or organismic levels is sparse. There is still a need for identifying novel and efficient TRPC5 channel modulators to study TRPC5 function. In this study, based on the hTRPC5 structure obtained by homology modeling and the predicted binding site, we have performed virtual screening of 212,736 compounds from the specs database(http://www.specs.net) to find potential hTRPC5 modulators. Lipinski and Veber rules, ADMET (Absorption, Distribution, Metabolism, Excretion, Toxicity) and PAINS (Pan Assay Interference structures) filters were used to screen the large database. Further, multi-software combination docking, cluster analysis and interaction analysis were used to select 20 potential active candidates with novel skeleton. 4 Hits, bearing appreciable binding affinity with hTRPC5 were selected for 40ns all-atom molecular dynamics (MD) simulations under explicit water conditions. The MD simulation results suggested that the 4 Hits binding induces a slight structural change and stabilizes the hTRPC5 structure. In addition, decomposition free energy demonstrated that residues TRP434, LEU437, MET438, ALA441, ILE484, ILE487, LEU488, LEU491, LEU515, ILE517, LEU518, LEU521, PHE531, THR607, VAL610, ILE611, VAL615 played the critical role on system stability. 4 Hits, as potential modulators of hTRPC5, may be potential leads to develop effective therapeutics hTRPC5-associated diseases.
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Affiliation(s)
- Bin Liu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Wei Zhang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
| | - Sheng Guo
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
| | - Zhili Zuo
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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33
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Bacsa B, Tiapko O, Stockner T, Groschner K. Mechanisms and significance of Ca 2+ entry through TRPC channels. CURRENT OPINION IN PHYSIOLOGY 2020; 17:25-33. [PMID: 33210055 PMCID: PMC7116371 DOI: 10.1016/j.cophys.2020.06.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The transient receptor potential (TRP) superfamily of plasma membrane cation channels has been recognized as a signaling hub in highly diverse settings of human physiopathology. In the past three decades of TRP research, attention was focused mainly on the channels Ca2+ signaling function, albeit additional cellular functions, aside of providing a Ca2+ entry pathway, have been identified. Our understanding of Ca2+ signaling by TRP proteins has recently been advanced by a gain in high-resolution structure information on these pore complexes, and by the development of novel tools to investigate their role in spatiotemporal Ca2+ handling. This review summarizes recent discoveries as well as remaining, unresolved aspects of the canonical subfamily of transient receptor potential channels (TRPC) research. We aim at a concise overview on current mechanistic concepts of Ca2+ entry through- and Ca2+ signaling by TRPC channels.
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Affiliation(s)
- Bernadett Bacsa
- Gottfried-Schatz-Research-Center - Biophysics, Medical University of Graz, Neue Stiftingtalstrasse 6/D04, 8010 Graz, Austria
| | - Oleksandra Tiapko
- Gottfried-Schatz-Research-Center - Biophysics, Medical University of Graz, Neue Stiftingtalstrasse 6/D04, 8010 Graz, Austria
| | - Thomas Stockner
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Waehringerstr. 13A, 1090 Vienna, Austria
| | - Klaus Groschner
- Gottfried-Schatz-Research-Center - Biophysics, Medical University of Graz, Neue Stiftingtalstrasse 6/D04, 8010 Graz, Austria
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34
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Chen X, Sooch G, Demaree IS, White FA, Obukhov AG. Transient Receptor Potential Canonical (TRPC) Channels: Then and Now. Cells 2020; 9:E1983. [PMID: 32872338 PMCID: PMC7565274 DOI: 10.3390/cells9091983] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 12/13/2022] Open
Abstract
Twenty-five years ago, the first mammalian Transient Receptor Potential Canonical (TRPC) channel was cloned, opening the vast horizon of the TRPC field. Today, we know that there are seven TRPC channels (TRPC1-7). TRPCs exhibit the highest protein sequence similarity to the Drosophila melanogaster TRP channels. Similar to Drosophila TRPs, TRPCs are localized to the plasma membrane and are activated in a G-protein-coupled receptor-phospholipase C-dependent manner. TRPCs may also be stimulated in a store-operated manner, via receptor tyrosine kinases, or by lysophospholipids, hypoosmotic solutions, and mechanical stimuli. Activated TRPCs allow the influx of Ca2+ and monovalent alkali cations into the cytosol of cells, leading to cell depolarization and rising intracellular Ca2+ concentration. TRPCs are involved in the continually growing number of cell functions. Furthermore, mutations in the TRPC6 gene are associated with hereditary diseases, such as focal segmental glomerulosclerosis. The most important recent breakthrough in TRPC research was the solving of cryo-EM structures of TRPC3, TRPC4, TRPC5, and TRPC6. These structural data shed light on the molecular mechanisms underlying TRPCs' functional properties and propelled the development of new modulators of the channels. This review provides a historical overview of the major advances in the TRPC field focusing on the role of gene knockouts and pharmacological tools.
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Affiliation(s)
- Xingjuan Chen
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an 710072, China;
| | - Gagandeep Sooch
- The Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (G.S.); (I.S.D.)
| | - Isaac S. Demaree
- The Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (G.S.); (I.S.D.)
| | - Fletcher A. White
- The Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Alexander G. Obukhov
- The Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (G.S.); (I.S.D.)
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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35
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Huang Q, Wang X, Lin X, Zhang J, You X, Shao A. The Role of Transient Receptor Potential Channels in Blood-Brain Barrier Dysfunction after Ischemic Stroke. Biomed Pharmacother 2020; 131:110647. [PMID: 32858500 DOI: 10.1016/j.biopha.2020.110647] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 08/11/2020] [Accepted: 08/16/2020] [Indexed: 12/25/2022] Open
Abstract
Stroke is the leading cause of long-term disability, demanding an ever-increasing need to find treatment. Transient receptor potential (TRP) channels are nonselective Ca2+-permeable channels, among which TRPC, TRPM, and TRPV are widely expressed in the brain. Dysfunction of the blood brain barrier (BBB) is a core feature of stroke and is associated with severity of injury. As studies have shown, TRP channels influence various neuronal functions by regulating the BBB. Here, we briefly review the role of TRP channel in the BBB dysfunction after stroke, and explore the therapeutic potential of TRP-targeted therapy.
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Affiliation(s)
- Qingxia Huang
- Department of Echocardiography, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoyu Wang
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Xianyi Lin
- Department of anesthesiology, Sir run run shaw hospital, school of medicine, zhejiang university, China
| | - Jianmin Zhang
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China; Brain Research Institute, Zhejiang University, Hangzhou, China; Collaborative Innovation Center for Brain Science, Zhejiang University, Hangzhou, China
| | - Xiangdong You
- Department of Echocardiography, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.
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36
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Balla T, Gulyas G, Kim YJ, Pemberton J. PHOSPHOINOSITIDES AND CALCIUM SIGNALING. A MARRIAGE ARRANGED IN ER-PM CONTACT SITES. CURRENT OPINION IN PHYSIOLOGY 2020; 17:149-157. [PMID: 32944676 DOI: 10.1016/j.cophys.2020.08.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Calcium (Ca2+) ions are critically important in orchestrating countless regulatory processes in eukaryotic cells. Consequently, cells tightly control cytoplasmic Ca2+ concentrations using a complex array of Ca2+-selective ion channels, transporters, and signaling effectors. Ca2+ transport through various cellular membranes is highly dependent on the intrinsic properties of specific membrane compartments and conversely, local Ca2+ changes have profound effects on the membrane lipid composition of such membrane sub-domains. In particular, inositol phospholipids are a minor class of phospholipids that play pivotal roles in the control of Ca2+-dependent signaling pathways. In this review, we will highlight some of the recent advances in this field as well as their impact in defining future research directions.
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Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Gergo Gulyas
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Yeun Ju Kim
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Joshua Pemberton
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
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37
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Camacho Londoño JE, Kuryshev V, Zorn M, Saar K, Tian Q, Hübner N, Nawroth P, Dietrich A, Birnbaumer L, Lipp P, Dieterich C, Freichel M. Transcriptional signatures regulated by TRPC1/C4-mediated Background Ca 2+ entry after pressure-overload induced cardiac remodelling. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 159:86-104. [PMID: 32738354 DOI: 10.1016/j.pbiomolbio.2020.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/03/2020] [Accepted: 07/21/2020] [Indexed: 01/17/2023]
Abstract
AIMS After summarizing current concepts for the role of TRPC cation channels in cardiac cells and in processes triggered by mechanical stimuli arising e.g. during pressure overload, we analysed the role of TRPC1 and TRPC4 for background Ca2+ entry (BGCE) and for cardiac pressure overload induced transcriptional remodelling. METHODS AND RESULTS Mn2+-quench analysis in cardiomyocytes from several Trpc-deficient mice revealed that both TRPC1 and TRPC4 are required for BGCE. Electrically-evoked cell shortening of cardiomyocytes from TRPC1/C4-DKO mice was reduced, whereas parameters of cardiac contractility and relaxation assessed in vivo were unaltered. As pathological cardiac remodelling in mice depends on their genetic background, and the development of cardiac remodelling was found to be reduced in TRPC1/C4-DKO mice on a mixed genetic background, we studied TRPC1/C4-DKO mice on a C57BL6/N genetic background. Cardiac hypertrophy was reduced in those mice after chronic isoproterenol infusion (-51.4%) or after one week of transverse aortic constriction (TAC; -73.0%). This last manoeuvre was preceded by changes in the pressure overload induced transcriptional program as analysed by RNA sequencing. Genes encoding specific collagens, the Mef2 target myomaxin and the gene encoding the mechanosensitive channel Piezo2 were up-regulated after TAC in wild type but not in TRPC1/C4-DKO hearts. CONCLUSIONS Deletion of the TRPC1 and TRPC4 channel proteins protects against development of pathological cardiac hypertrophy independently of the genetic background. To determine if the TRPC1/C4-dependent changes in the pressure overload induced alterations in the transcriptional program causally contribute to cardio-protection needs to be elaborated in future studies.
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Affiliation(s)
- Juan E Camacho Londoño
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, 69120, Germany.
| | - Vladimir Kuryshev
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120, Heidelberg, Germany; Innere Medizin III, Bioinformatik und Systemkardiologie, Klaus Tschira Institute for Computational Cardiology, Ruprecht-Karls-Universität Heidelberg, 69120, Heidelberg, Germany
| | - Markus Zorn
- Department of Medicine I and Clinical Chemistry, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Kathrin Saar
- Max-Delbrück-Centrum für Molekulare Medizin (MDC), 13125, Berlin, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, 13347, Berlin, Germany
| | - Qinghai Tian
- Medical Faculty, Centre for Molecular Signalling (PZMS), Institute for Molecular Cell Biology and Research Center for Molecular Imaging and Screening, Saarland University, 66421 Homburg/Saar, Germany
| | - Norbert Hübner
- Max-Delbrück-Centrum für Molekulare Medizin (MDC), 13125, Berlin, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, 13347, Berlin, Germany; Berlin Institute of Health (BIH), 10178, Berlin, Germany; Charité -Universitätsmedizin, 10117, Berlin, Germany
| | - Peter Nawroth
- Department of Medicine I and Clinical Chemistry, University Hospital Heidelberg, 69120, Heidelberg, Germany; German Center for Diabetes Research (DZD), Germany; Institute for Diabetes and Cancer IDC Helmholtz Center Munich, Neuherberg, Germany; Joint Heidelberg-IDC Translational Diabetes Program, Dept. of Medicine I, Heidelberg University Hospital, Heidelberg, Germany
| | - Alexander Dietrich
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Member of the German Center for Lung Research (DZL), Ludwig-Maximilians-Universität, 80336, München, Germany
| | - Lutz Birnbaumer
- Laboratory of Neurobiology, NIEHS, North Carolina, USA and Institute of Biomedical Research (BIOMED), Catholic University of Argentina, C1107AFF Buenos Aires, Argentina
| | - Peter Lipp
- Medical Faculty, Centre for Molecular Signalling (PZMS), Institute for Molecular Cell Biology and Research Center for Molecular Imaging and Screening, Saarland University, 66421 Homburg/Saar, Germany
| | - Christoph Dieterich
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, 69120, Germany; Innere Medizin III, Bioinformatik und Systemkardiologie, Klaus Tschira Institute for Computational Cardiology, Ruprecht-Karls-Universität Heidelberg, 69120, Heidelberg, Germany
| | - Marc Freichel
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, 69120, Germany.
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How TRPC Channels Modulate Hippocampal Function. Int J Mol Sci 2020; 21:ijms21113915. [PMID: 32486187 PMCID: PMC7312571 DOI: 10.3390/ijms21113915] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022] Open
Abstract
Transient receptor potential canonical (TRPC) proteins constitute a group of receptor-operated calcium-permeable nonselective cationic membrane channels of the TRP superfamily. They are largely expressed in the hippocampus and are able to modulate neuronal functions. Accordingly, they have been involved in different hippocampal functions such as learning processes and different types of memories, as well as hippocampal dysfunctions such as seizures. This review covers the mechanisms of activation of these channels, how these channels can modulate neuronal excitability, in particular the after-burst hyperpolarization, and in the persistent activity, how they control synaptic plasticity including pre- and postsynaptic processes and how they can interfere with cell survival and neurogenesis.
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Thakur DP, Wang Q, Jeon J, Tian JB, Zhu MX. Intracellular acidification facilitates receptor-operated TRPC4 activation through PLCδ1 in a Ca 2+ -dependent manner. J Physiol 2020; 598:2651-2667. [PMID: 32338378 DOI: 10.1113/jp279658] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 04/20/2020] [Indexed: 12/28/2022] Open
Abstract
KEY POINTS Receptor-operated activation of TRPC4 cation channels requires Gi/o proteins and phospholipase-Cδ1 (PLCδ1) activation by intracellular Ca2+ . Concurrent stimulation of the Gq/11 pathway accelerates Gi/o activation of TRPC4, which is not mimicked by increasing cytosolic Ca2+ . The kinetic effect of Gq/11 was diminished by alkaline intracellular pH (pHi ) and increased pHi buffer capacity. Acidic pHi (6.75-6.25) together with the cytosolic Ca2+ rise accelerated Gi/o -mediated TRPC4 activation. Protons exert their facilitation effect through Ca2+ -dependent activation of PLCδ1. The data suggest that the Gq/11 -PLCβ pathway facilitates Gi/o activation of TRPC4 through hydrolysing phosphatidylinositol 4,5-bisphosphate (PIP2 ) to produce the initial proton signal that triggers a self-propagating PLCδ1 activity supported by regenerative H+ and Ca2+ . The findings provide novel mechanistic insights into receptor-operated TRPC4 activation by coincident Gq/11 and Gi/o pathways and shed light on how aberrant activation of TRPC4 may occur under pathological conditions to cause cell damage. ABSTRACT Transient Receptor Potential Canonical 4 (TRPC4) forms non-selective cation channels activated downstream from receptors that signal through G proteins. Our recent work suggests that TRPC4 channels are particularly coupled to pertussis toxin-sensitive Gi/o proteins, with a co-dependence on phospholipase-Cδ1 (PLCδ1). The Gi/o -mediated TRPC4 activation is dually dependent on and bimodally regulated by phosphatidylinositol 4,5-bisphosphate (PIP2 ), the substrate hydrolysed by PLC, and intracellular Ca2+ . As a byproduct of PLC-mediated PIP2 hydrolysis, protons have been shown to play an important role in the activation of Drosophila TRP channels. However, how intracellular pH affects mammalian TRPC channels remains obscure. Here, using patch-clamp recordings of HEK293 cells heterologously co-expressing mouse TRPC4β and the Gi/o -coupled μ opioid receptor, we investigated the role of intracellular protons on Gi/o -mediated TRPC4 activation. We found that acidic cytosolic pH greatly accelerated the rate of TRPC4 activation without altering the maximal current density and this effect was dependent on intracellular Ca2+ elevation. However, protons did not accelerate channel activation by directly acting upon TRPC4. We additionally demonstrated that protons exert their effect through sensitization of PLCδ1 to Ca2+ , which in turn promotes PLCδ1 activity and further potentiates TRPC4 via a positive feedback mechanism. The mechanism elucidated here helps explain how Gi/o and Gq/11 co-stimulation induces a faster activation of TRPC4 than Gi/o activation alone and highlights again the critical role of PLCδ1 in TRPC4 gating.
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Affiliation(s)
- Dhananjay P Thakur
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Qiaochu Wang
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Jaepyo Jeon
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Jin-Bin Tian
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
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Genova T, Gaglioti D, Munaron L. Regulation of Vessel Permeability by TRP Channels. Front Physiol 2020; 11:421. [PMID: 32431625 PMCID: PMC7214926 DOI: 10.3389/fphys.2020.00421] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 04/07/2020] [Indexed: 12/13/2022] Open
Abstract
The vascular endothelium constitutes a semi-permeable barrier between blood and interstitial fluids. Since an augmented endothelial permeability is often associated to pathological states, understanding the molecular basis for its regulation is a crucial biomedical and clinical challenge. This review focuses on the processes controlling paracellular permeability that is the permeation of fluids between adjacent endothelial cells (ECs). Cytosolic calcium changes are often detected as early events preceding the alteration of the endothelial barrier (EB) function. For this reason, great interest has been devoted in the last decades to unveil the molecular mechanisms underlying calcium fluxes and their functional relationship with vessel permeability. Beyond the dicotomic classification between store-dependent and independent calcium entry at the plasma membrane level, the search for the molecular components of the related calcium-permeable channels revealed a difficult task for intrinsic and technical limitations. The contribution of redundant channel-forming proteins including members of TRP superfamily and Orai1, together with the very complex intracellular modulatory pathways, displays a huge variability among tissues and along the vascular tree. Moreover, calcium-independent events could significantly concur to the regulation of vascular permeability in an intricate and fascinating multifactorial framework.
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Affiliation(s)
- Tullio Genova
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Deborah Gaglioti
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Luca Munaron
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
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Formoso K, Susperreguy S, Freichel M, Birnbaumer L. RNA-seq analysis reveals TRPC genes to impact an unexpected number of metabolic and regulatory pathways. Sci Rep 2020; 10:7227. [PMID: 32350291 PMCID: PMC7190874 DOI: 10.1038/s41598-020-61177-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 02/21/2020] [Indexed: 12/12/2022] Open
Abstract
The seven-member transient receptor potential canonical genes (TRPC1-7) encode cation channels linked to several human diseases. There is little understanding of the participation of each TRPC in each pathology, considering functional redundancy. Also, most of the inhibitors available are not specific. Thus, we developed mice that lack all of the TRPCs and performed a transcriptome analysis in eight tissues. The aim of this research was to address the impact of the absence of all TRPC channels on gene expression. We obtained a total of 4305 differentially expressed genes (DEGs) in at least one tissue where spleen showed the highest number of DEGs (1371). Just 21 genes were modified in all the tissues. Performing a pathway enrichment analysis, we found that many important signaling pathways were modified in more than one tissue, including PI3K (phosphatidylinositol 3-kinase/protein kinase-B) signaling pathway, cytokine-cytokine receptor interaction, extracellular matrix (ECM)-receptor interaction and circadian rhythms. We describe for the first time the changes at the transcriptome level due to the lack of all TRPC proteins in a mouse model and provide a starting point to understand the function of TRPC channels and their possible roles in pathologies.
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Affiliation(s)
- Karina Formoso
- Institute for Biomedical Research (BIOMED UCA-CONICET). School of Medical Sciences, Catholic University of Argentina (UCA), Buenos Aires, C1107AFF, Argentina
| | - Sebastian Susperreguy
- Institute for Biomedical Research (BIOMED UCA-CONICET). School of Medical Sciences, Catholic University of Argentina (UCA), Buenos Aires, C1107AFF, Argentina
| | - Marc Freichel
- Institute of Physiology and Pathophysiology, Heidelberg University, 69120, Heidelberg, Germany
| | - Lutz Birnbaumer
- Institute for Biomedical Research (BIOMED UCA-CONICET). School of Medical Sciences, Catholic University of Argentina (UCA), Buenos Aires, C1107AFF, Argentina. .,Neurobiology Laboratory, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, 27709, USA.
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Bendiks L, Geiger F, Gudermann T, Feske S, Dietrich A. Store-operated Ca 2+ entry in primary murine lung fibroblasts is independent of classical transient receptor potential (TRPC) channels and contributes to cell migration. Sci Rep 2020; 10:6812. [PMID: 32321939 PMCID: PMC7176639 DOI: 10.1038/s41598-020-63677-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 03/16/2020] [Indexed: 12/14/2022] Open
Abstract
Stromal interaction molecules (STIM1, 2) are acting as sensors for Ca2+ in intracellular stores and activate Orai channels at the plasma membrane for store-operated Ca2+ entry (SOCE), while classical transient receptor potential (TRPC) channel mediate receptor-operated Ca2+ entry (ROCE). Several reports, however, indicate a role for TRPC in SOCE in certain cell types. Here, we analyzed Ca2+ influx and cell function in TRPC1/6-deficient (TRPC1/6-/-) and STIM1/2- deficient (STIM1/2ΔpmLF) primary murine lung fibroblasts (pmLF). As expected, SOCE was decreased in STIM1/2- deficient pmLF and ROCE was decreased in TRPC1/6-/- pmLF compared to control cells. By contrast, SOCE was not significantly different in TRPC1/6-/- pmLF and ROCE was similar in STIM1/2-deficient pmLF compared to Wt cells. Most interestingly, cell proliferation, migration and nuclear localization of nuclear factor of activated T-cells (NFATc1 and c3) were decreased after ablation of STIM1/2 proteins in pmLF. In conclusion, TRPC1/6 channels are not involved in SOCE and STIM1/2 deficiency resulted in decreased cell proliferation and migration in pmLF.
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Affiliation(s)
- Larissa Bendiks
- Walther Straub Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL), Medical Faculty, LMU-Munich, Munich, Germany
| | - Fabienne Geiger
- Walther Straub Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL), Medical Faculty, LMU-Munich, Munich, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL), Medical Faculty, LMU-Munich, Munich, Germany
| | - Stefan Feske
- Department of Pathology, New York University School of Medicine, New York, NY, 10016, USA
| | - Alexander Dietrich
- Walther Straub Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL), Medical Faculty, LMU-Munich, Munich, Germany.
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Kytikova OY, Novgorodtseva TP, Denisenko YK, Antonyuk MV, Gvozdenko TA. Dysfunction of transient receptor potential ion channels as an important pathophysiological mechanism in asthma. RUSSIAN OPEN MEDICAL JOURNAL 2020. [DOI: 10.15275/rusomj.2020.0102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Asthma is a chronic heterogeneous disease characterized by chronic inflammation and bronchial hyperreactivity. Neurogenic inflammation is one of the important causes of hyperreactivity. Dysfunction of transient receptor potential (TRP) ion channels underlies the development of neurogenic inflammation, bronchial hyperreactivity and respiratory symptoms of asthma such as bronchospasm and cough. TRP channels are expressed in the respiratory tract. Their activation is mediated by endogenous and exogenous factors involved in the pathogenesis of asthma. The study of functioning and regulation of TRP channels is relevant, as they could be important therapeutic targets for asthma. The aim of the review is to summarize modern ideas about the mechanisms of functioning and regulation of members of the TRP channel superfamily, the role of which in lung pathology and physiology are the best studied.
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Affiliation(s)
- Oxana Yu. Kytikova
- Vladivostok Branch of Far Eastern Scientific Center of Physiology and Pathology of Respiration – Institute of Medical Climatology and Rehabilitative Treatment
| | - Tatyana P. Novgorodtseva
- Vladivostok Branch of Far Eastern Scientific Center of Physiology and Pathology of Respiration – Institute of Medical Climatology and Rehabilitative Treatment
| | - Yulia K. Denisenko
- Vladivostok Branch of Far Eastern Scientific Center of Physiology and Pathology of Respiration – Institute of Medical Climatology and Rehabilitative Treatment
| | - Marina V. Antonyuk
- Vladivostok Branch of Far Eastern Scientific Center of Physiology and Pathology of Respiration – Institute of Medical Climatology and Rehabilitative Treatment
| | - Tatyana A. Gvozdenko
- Vladivostok Branch of Far Eastern Scientific Center of Physiology and Pathology of Respiration – Institute of Medical Climatology and Rehabilitative Treatment
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Graziani A, Bacsa B, Krivic D, Wiedner P, Curcic S, Schindl R, Tiapko O, Groschner K. Light-Mediated Control over TRPC3-Mediated NFAT Signaling. Cells 2020; 9:cells9030556. [PMID: 32120825 PMCID: PMC7140526 DOI: 10.3390/cells9030556] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 01/20/2023] Open
Abstract
Canonical transient receptor potential (TRPC) channels were identified as key players in maladaptive remodeling, with nuclear factor of activated T-cells (NFAT) transcription factors serving as downstream targets of TRPC-triggered Ca2+ entry in these pathological processes. Strikingly, the reconstitution of TRPC-NFAT signaling by heterologous expression yielded controversial results. Specifically, nuclear translocation of NFAT1 was found barely responsive to recombinant TRPC3, presumably based on the requirement of certain spatiotemporal signaling features. Here, we report efficient control of NFAT1 nuclear translocation in human embryonic kidney 293 (HEK293) cells by light, using a new photochromic TRPC benzimidazole activator (OptoBI-1) and a TRPC3 mutant with modified activator sensitivity. NFAT1 nuclear translocation was measured along with an all-optical protocol to record local and global Ca2+ pattern generated during light-mediated activation/deactivation cycling of TRPC3. Our results unveil the ability of wild-type TRPC3 to produce constitutive NFAT nuclear translocation. Moreover, we demonstrate that TRPC3 mutant that lacks basal activity enables spatiotemporally precise control over NFAT1 activity by photopharmacology. Our results suggest tight linkage between TRPC3 activity and NFAT1 nuclear translocation based on global cellular Ca2+ signals.
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Affiliation(s)
| | | | | | | | | | | | | | - Klaus Groschner
- Correspondence: (O.T.); (K.G.); Tel.: +43-316-385-71500 (K.G)
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TRPC Channels in Cardiac Plasticity. Cells 2020; 9:cells9020454. [PMID: 32079284 PMCID: PMC7072762 DOI: 10.3390/cells9020454] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/13/2020] [Accepted: 02/14/2020] [Indexed: 01/21/2023] Open
Abstract
The heart flexibly changes its structure in response to changing environments and oxygen/nutrition demands of the body. Increased and decreased mechanical loading induces hypertrophy and atrophy of cardiomyocytes, respectively. In physiological conditions, these structural changes of the heart are reversible. However, chronic stresses such as hypertension or cancer cachexia cause irreversible remodeling of the heart, leading to heart failure. Accumulating evidence indicates that calcium dyshomeostasis and aberrant reactive oxygen species production cause pathological heart remodeling. Canonical transient receptor potential (TRPC) is a nonselective cation channel subfamily whose multimodal activation or modulation of channel activity play important roles in a plethora of cellular physiology. Roles of TRPC channels in cardiac physiology have been reported in pathological cardiac remodeling. In this review, we summarize recent findings regarding the importance of TRPC channels in flexible cardiac remodeling (i.e., cardiac plasticity) in response to environmental stresses and discuss questions that should be addressed in the near future.
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Wang H, Cheng X, Tian J, Xiao Y, Tian T, Xu F, Hong X, Zhu MX. TRPC channels: Structure, function, regulation and recent advances in small molecular probes. Pharmacol Ther 2020; 209:107497. [PMID: 32004513 DOI: 10.1016/j.pharmthera.2020.107497] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/14/2020] [Indexed: 02/08/2023]
Abstract
Transient receptor potential canonical (TRPC) channels constitute a group of receptor-operated calcium-permeable nonselective cation channels of the TRP superfamily. The seven mammalian TRPC members, which can be further divided into four subgroups (TRPC1, TRPC2, TRPC4/5, and TRPC3/6/7) based on their amino acid sequences and functional similarities, contribute to a broad spectrum of cellular functions and physiological roles. Studies have revealed complexity of their regulation involving several components of the phospholipase C pathway, Gi and Go proteins, and internal Ca2+ stores. Recent advances in cryogenic electron microscopy have provided several high-resolution structures of TRPC channels. Growing evidence demonstrates the involvement of TRPC channels in diseases, particularly the link between genetic mutations of TRPC6 and familial focal segmental glomerulosclerosis. Because TRPCs were discovered by the molecular identity first, their pharmacology had lagged behind. This is rapidly changing in recent years owning to great efforts from both academia and industry. A number of potent tool compounds from both synthetic and natural products that selective target different subtypes of TRPC channels have been discovered, including some preclinical drug candidates. This review will cover recent advancements in the understanding of TRPC channel regulation, structure, and discovery of novel TRPC small molecular probes over the past few years, with the goal of facilitating drug discovery for the study of TRPCs and therapeutic development.
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Affiliation(s)
- Hongbo Wang
- Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education; Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China.
| | - Xiaoding Cheng
- State Key Laboratory of Virology, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (MOE) and Hubei Province Engineering and Technology Research Center for Fluorinated Pharmaceuticals, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
| | - Jinbin Tian
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Yuling Xiao
- State Key Laboratory of Virology, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (MOE) and Hubei Province Engineering and Technology Research Center for Fluorinated Pharmaceuticals, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
| | - Tian Tian
- Innovation Center for Traditional Tibetan Medicine Modernization and Quality Control, Medical College, Department of Chemistry and Environmental Science, School of Science, Tibet University, Lhasa 850000, China
| | - Fuchun Xu
- Innovation Center for Traditional Tibetan Medicine Modernization and Quality Control, Medical College, Department of Chemistry and Environmental Science, School of Science, Tibet University, Lhasa 850000, China
| | - Xuechuan Hong
- State Key Laboratory of Virology, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (MOE) and Hubei Province Engineering and Technology Research Center for Fluorinated Pharmaceuticals, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China; Innovation Center for Traditional Tibetan Medicine Modernization and Quality Control, Medical College, Department of Chemistry and Environmental Science, School of Science, Tibet University, Lhasa 850000, China.
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
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TRPC Channels: Dysregulation and Ca 2+ Mishandling in Ischemic Heart Disease. Cells 2020; 9:cells9010173. [PMID: 31936700 PMCID: PMC7017417 DOI: 10.3390/cells9010173] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/03/2020] [Accepted: 01/08/2020] [Indexed: 12/17/2022] Open
Abstract
Transient receptor potential canonical (TRPC) channels are ubiquitously expressed in excitable and non-excitable cardiac cells where they sense and respond to a wide variety of physical and chemical stimuli. As other TRP channels, TRPC channels may form homo or heterotetrameric ion channels, and they can associate with other membrane receptors and ion channels to regulate intracellular calcium concentration. Dysfunctions of TRPC channels are involved in many types of cardiovascular diseases. Significant increase in the expression of different TRPC isoforms was observed in different animal models of heart infarcts and in vitro experimental models of ischemia and reperfusion. TRPC channel-mediated increase of the intracellular Ca2+ concentration seems to be required for the activation of the signaling pathway that plays minor roles in the healthy heart, but they are more relevant for cardiac responses to ischemia, such as the activation of different factors of transcription and cardiac hypertrophy, fibrosis, and angiogenesis. In this review, we highlight the current knowledge regarding TRPC implication in different cellular processes related to ischemia and reperfusion and to heart infarction.
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Post-Translational Modification and Natural Mutation of TRPC Channels. Cells 2020; 9:cells9010135. [PMID: 31936014 PMCID: PMC7016788 DOI: 10.3390/cells9010135] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/03/2020] [Accepted: 01/03/2020] [Indexed: 02/06/2023] Open
Abstract
Transient Receptor Potential Canonical (TRPC) channels are homologues of Drosophila TRP channel first cloned in mammalian cells. TRPC family consists of seven members which are nonselective cation channels with a high Ca2+ permeability and are activated by a wide spectrum of stimuli. These channels are ubiquitously expressed in different tissues and organs in mammals and exert a variety of physiological functions. Post-translational modifications (PTMs) including phosphorylation, N-glycosylation, disulfide bond formation, ubiquitination, S-nitrosylation, S-glutathionylation, and acetylation play important roles in the modulation of channel gating, subcellular trafficking, protein-protein interaction, recycling, and protein architecture. PTMs also contribute to the polymodal activation of TRPCs and their subtle regulation in diverse physiological contexts and in pathological situations. Owing to their roles in the motor coordination and regulation of kidney podocyte structure, mutations of TRPCs have been implicated in diseases like cerebellar ataxia (moonwalker mice) and focal and segmental glomerulosclerosis (FSGS). The aim of this review is to comprehensively integrate all reported PTMs of TRPCs, to discuss their physiological/pathophysiological roles if available, and to summarize diseases linked to the natural mutations of TRPCs.
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Structure-Function Relationship and Physiological Roles of Transient Receptor Potential Canonical (TRPC) 4 and 5 Channels. Cells 2019; 9:cells9010073. [PMID: 31892199 PMCID: PMC7017149 DOI: 10.3390/cells9010073] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/24/2019] [Accepted: 12/24/2019] [Indexed: 12/11/2022] Open
Abstract
The study of the structure–function relationship of ion channels has been one of the most challenging goals in contemporary physiology. Revelation of the three-dimensional (3D) structure of ion channels has facilitated our understanding of many of the submolecular mechanisms inside ion channels, such as selective permeability, voltage dependency, agonist binding, and inter-subunit multimerization. Identifying the structure–function relationship of the ion channels is clinically important as well since only such knowledge can imbue potential therapeutics with practical possibilities. In a sense, recent advances in the understanding of the structure–relationship of transient receptor potential canonical (TRPC) channels look promising since human TRPC channels are calcium-permeable, non-selective cation channels expressed in many tissues such as the gastrointestinal (GI) tract, kidney, heart, vasculature, and brain. TRPC channels are known to regulate GI contractility and motility, pulmonary hypertension, right ventricular hypertrophy, podocyte injury, seizure, fear, anxiety-like behavior, and many others. In this article, we tried to elaborate recent findings of Cryo-EM (cryogenic-electron microscopy) based structural information of TRPC 4 and 5 channels and domain-specific functions of the channel, such as G-protein mediated activation mechanism, extracellular modification of the channel, homo/hetero-tetramerization, and pharmacological gating mechanisms.
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Fiedler S, Storch U, Erdogmus S, Gudermann T, Mederos Y Schnitzler M, Dietrich A. Small Fluorescein Arsenical Hairpin-Based Förster Resonance Energy Transfer Analysis Reveals Changes in Amino- to Carboxyl-Terminal Interactions upon OAG Activation of Classical Transient Receptor Potential 6. Mol Pharmacol 2019; 96:90-98. [PMID: 31171574 DOI: 10.1124/mol.119.115949] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 05/02/2019] [Indexed: 01/19/2023] Open
Abstract
Although the overall structure of many classical transient receptor potential proteins (TRPC), including human and murine TRPC6, were recently resolved by cryoelectron microscopy analysis, structural changes during channel activation by 1-oleoyl-1-acetyl-sn-glycerol (OAG), the membrane-permeable analog of diacylglycerol, were not defined. Moreover, data on carboxyl- and amino-terminal interactions were not provided, as the amino-terminal regions of murine and human TRPC6 were not resolved. Therefore, we employed a Förster resonance energy transfer (FRET) approach using a small fluorescein arsenical hairpin (FlAsH) targeted to a short tetracysteine sequence at the unresolved amino-terminus and cerulean, a cyan fluorescent protein, as a tag at the carboxyl-terminus of the murine TRPC6 protein. After OAG as well as GSK-1702934A activation, FRET efficiency was simultaneously and significantly reduced, indicating a decreased interaction between the amino to carboxyl termini in the functional tagged murine TRPC6 tetramer (TRPC6 WT) heterologously expressed in human embryonic kidney 293T cells. There was a significant reduction in the FRET signal obtained from analysis of murine TRPC6 FRET constructs with homologous amino-terminal mutations (M131T, G108S) that had been identified in human patients with inherited focal segmental glomerulosclerosis, a condition that can lead to end-stage renal disease. A novel, designed loss-of-function TRPC6 mutation (N109A) in the amino-terminus in close proximity to the carboxyl-terminus produced similar FRET ratios. SIGNIFICANCE STATEMENT: Our data show for the first time that FlAsH-tagging of ion channels is a promising tool to study conformational changes after channel opening and may significantly advance the analysis of ion channel activation as well as their mutants involved in channelopathies.
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Affiliation(s)
- Susanne Fiedler
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL) (S.F., U.S., S.E., T.G., M.M.S., A.D.) and Institute for Cardiovascular Prevention (IPEK) (U.S.), Ludwig-Maximilians-Universitaet Muenchen, Munich, Germany; German Centre for Cardiovascular Research (DZHK), Munich Heart Alliance, Munich, Germany (T.G., M.M.S.); and Comprehensive Pneumology Center Munich (CPC-M), Munich, Germany (T.G., A.D.)
| | - Ursula Storch
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL) (S.F., U.S., S.E., T.G., M.M.S., A.D.) and Institute for Cardiovascular Prevention (IPEK) (U.S.), Ludwig-Maximilians-Universitaet Muenchen, Munich, Germany; German Centre for Cardiovascular Research (DZHK), Munich Heart Alliance, Munich, Germany (T.G., M.M.S.); and Comprehensive Pneumology Center Munich (CPC-M), Munich, Germany (T.G., A.D.)
| | - Serap Erdogmus
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL) (S.F., U.S., S.E., T.G., M.M.S., A.D.) and Institute for Cardiovascular Prevention (IPEK) (U.S.), Ludwig-Maximilians-Universitaet Muenchen, Munich, Germany; German Centre for Cardiovascular Research (DZHK), Munich Heart Alliance, Munich, Germany (T.G., M.M.S.); and Comprehensive Pneumology Center Munich (CPC-M), Munich, Germany (T.G., A.D.)
| | - Thomas Gudermann
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL) (S.F., U.S., S.E., T.G., M.M.S., A.D.) and Institute for Cardiovascular Prevention (IPEK) (U.S.), Ludwig-Maximilians-Universitaet Muenchen, Munich, Germany; German Centre for Cardiovascular Research (DZHK), Munich Heart Alliance, Munich, Germany (T.G., M.M.S.); and Comprehensive Pneumology Center Munich (CPC-M), Munich, Germany (T.G., A.D.)
| | - Michael Mederos Y Schnitzler
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL) (S.F., U.S., S.E., T.G., M.M.S., A.D.) and Institute for Cardiovascular Prevention (IPEK) (U.S.), Ludwig-Maximilians-Universitaet Muenchen, Munich, Germany; German Centre for Cardiovascular Research (DZHK), Munich Heart Alliance, Munich, Germany (T.G., M.M.S.); and Comprehensive Pneumology Center Munich (CPC-M), Munich, Germany (T.G., A.D.)
| | - Alexander Dietrich
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL) (S.F., U.S., S.E., T.G., M.M.S., A.D.) and Institute for Cardiovascular Prevention (IPEK) (U.S.), Ludwig-Maximilians-Universitaet Muenchen, Munich, Germany; German Centre for Cardiovascular Research (DZHK), Munich Heart Alliance, Munich, Germany (T.G., M.M.S.); and Comprehensive Pneumology Center Munich (CPC-M), Munich, Germany (T.G., A.D.)
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