1
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Luo Z, Zhang X, Fleig A, Romo D, Hull KG, Horgen FD, Sun HS, Feng ZP. TRPM7 in neurodevelopment and therapeutic prospects for neurodegenerative disease. Cell Calcium 2024; 120:102886. [PMID: 38631163 DOI: 10.1016/j.ceca.2024.102886] [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: 12/17/2023] [Revised: 04/02/2024] [Accepted: 04/05/2024] [Indexed: 04/19/2024]
Abstract
Neurodevelopment, a complex and highly regulated process, plays a foundational role in shaping the structure and function of the nervous system. The transient receptor potential melastatin 7 (TRPM7), a divalent cation channel with an α-kinase domain, mediates a wide range of cellular functions, including proliferation, migration, cell adhesion, and survival, all of which are essential processes in neurodevelopment. The global knockout of either TRPM7 or TRPM7-kinase is embryonically lethal, highlighting the crucial role of TRPM7 in development in vivo. Subsequent research further revealed that TRPM7 is indeed involved in various key processes throughout neurodevelopment, from maintaining pluripotency during embryogenesis to regulating gastrulation, neural tube closure, axonal outgrowth, synaptic density, and learning and memory. Moreover, a discrepancy in TRPM7 expression and/or function has been associated with neuropathological conditions, including ischemic stroke, Alzheimer's disease, and Parkinson's disease. Understanding the mechanisms of proper neurodevelopment may provide us with the knowledge required to develop therapeutic interventions that can overcome the challenges of regeneration in CNS injuries and neurodegenerative diseases. Considering that ion channels are the third-largest class targeted for drug development, TRPM7's dual roles in development and degeneration emphasize its therapeutic potential. This review provides a comprehensive overview of the current literature on TRPM7 in various aspects of neurodevelopment. It also discusses the links between neurodevelopment and neurodegeneration, and highlights TRPM7 as a potential therapeutic target for neurodegenerative disorders, with a focus on repair and regeneration.
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Affiliation(s)
- Zhengwei Luo
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada; Department of Surgery, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Xinyang Zhang
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada; Department of Surgery, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Andrea Fleig
- Center for Biomedical Research at The Queen's Medical Center and John A. Burns School of Medicine and Cancer Center at the University of Hawaii, Honolulu, HI, 96720, USA
| | - Daniel Romo
- Department of Chemistry & Biochemistry, Baylor University, Waco, TX 76798-7348, USA; The CPRIT Synthesis and Drug-Lead Discovery Laboratory, Baylor University, Waco, TX 76798, USA
| | - Kenneth G Hull
- Department of Chemistry & Biochemistry, Baylor University, Waco, TX 76798-7348, USA
| | - F David Horgen
- Department of Natural Sciences, Hawaii Pacific University, Kaneohe, HI, 96744, USA
| | - Hong-Shuo Sun
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada; Department of Surgery, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada; Department of Pharmacology, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada; Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario, M5S 3M2, Canada.
| | - Zhong-Ping Feng
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
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2
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Yao G, Parris MR, Kuo WC, Pörzgen P, Castillo B, Mason ES, Chinchilla A, Huang J, Suzuki S, Ross R, Akana E, Vander Schuit S, Miller SP, Penner R, Sun HS, Feng ZP, Hull KG, Romo D, Fleig A, Horgen FD. Transient Receptor Potential Melastatin 7 (TRPM7) Ion Channel Inhibitors: Preliminary SAR and Conformational Studies of Xenicane Diterpenoids from the Hawaiian Soft Coral Sarcothelia edmondsoni. JOURNAL OF NATURAL PRODUCTS 2024; 87:783-797. [PMID: 38537009 DOI: 10.1021/acs.jnatprod.3c00942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Waixenicin A, a xenicane diterpene from the octocoral Sarcothelia edmondsoni, is a selective, potent inhibitor of the TRPM7 ion channel. To study the structure-activity relationship (SAR) of waixenicin A, we isolated and assayed related diterpenes from S. edmondsoni. In addition to known waixenicins A (1) and B (2), we purified six xenicane diterpenes, 7S,8S-epoxywaixenicins A (3) and B (4), 12-deacetylwaixenicin A (5), waixenicin E (6), waixenicin F (7), and 20-acetoxyxeniafaraunol B (8). We elucidated the structures of 3-8 by NMR and MS analyses. Compounds 1, 2, 3, 4, and 6 inhibited TRPM7 activity in a cell-based assay, while 5, 7, and 8 were inactive. A preliminary SAR emerged showing that alterations to the nine-membered ring of 1 did not reduce activity, while the 12-acetoxy group, in combination with the dihydropyran, appears to be necessary for TRPM7 inhibition. The bioactive compounds are proposed to be latent electrophiles by formation of a conjugated oxocarbenium ion intermediate. Whole-cell patch-clamp experiments demonstrated that waixenicin A inhibition is irreversible, consistent with a covalent inhibitor, and showed nanomolar potency for waixenicin B (2). Conformational analysis (DFT) of 1, 3, 7, and 8 revealed insights into the conformation of waixenicin A and congeners and provided information regarding the stabilization of the proposed pharmacophore.
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Affiliation(s)
- Guangmin Yao
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
- Chemistry and Biochemistry, Hawaii Pacific University, Kaneohe, Hawaii 96744, United States
| | - Matthew R Parris
- Department of Chemistry & Biochemistry, Baylor University, Waco, Texas 76798-7348, United States
| | - W Cedric Kuo
- Chemistry and Biochemistry, Hawaii Pacific University, Kaneohe, Hawaii 96744, United States
| | - Peter Pörzgen
- Chemistry and Biochemistry, Hawaii Pacific University, Kaneohe, Hawaii 96744, United States
| | - Brandi Castillo
- Chemistry and Biochemistry, Hawaii Pacific University, Kaneohe, Hawaii 96744, United States
| | - Evan S Mason
- Department of Chemistry & Biochemistry, Baylor University, Waco, Texas 76798-7348, United States
| | - Andres Chinchilla
- Department of Chemistry & Biochemistry, Baylor University, Waco, Texas 76798-7348, United States
| | - Junhao Huang
- Laboratory of Cell and Molecular Signaling, Center for Biomedical Research at The Queen's Medical Center, Honolulu, Hawaii 96813, United States
| | - Sayuri Suzuki
- Laboratory of Cell and Molecular Signaling, Center for Biomedical Research at The Queen's Medical Center, Honolulu, Hawaii 96813, United States
| | - Rylee Ross
- Chemistry and Biochemistry, Hawaii Pacific University, Kaneohe, Hawaii 96744, United States
| | - Ellis Akana
- Chemistry and Biochemistry, Hawaii Pacific University, Kaneohe, Hawaii 96744, United States
| | - Savana Vander Schuit
- Chemistry and Biochemistry, Hawaii Pacific University, Kaneohe, Hawaii 96744, United States
| | - Steven P Miller
- Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, British Columbia V6H 3N1, Canada
| | - Reinhold Penner
- Laboratory of Cell and Molecular Signaling, Center for Biomedical Research at The Queen's Medical Center, Honolulu, Hawaii 96813, United States
| | | | | | - Kenneth G Hull
- Department of Chemistry & Biochemistry, Baylor University, Waco, Texas 76798-7348, United States
- The Baylor Synthesis and Drug-Lead Discovery Laboratory, Baylor University, Waco, Texas 76798, United States
| | - Daniel Romo
- Department of Chemistry & Biochemistry, Baylor University, Waco, Texas 76798-7348, United States
| | - Andrea Fleig
- Laboratory of Cell and Molecular Signaling, Center for Biomedical Research at The Queen's Medical Center, Honolulu, Hawaii 96813, United States
| | - F David Horgen
- Chemistry and Biochemistry, Hawaii Pacific University, Kaneohe, Hawaii 96744, United States
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3
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Xie Z, Abumaria N. Effect of truncation on TRPM7 channel activity. Channels (Austin) 2023; 17:2200874. [PMID: 37040321 PMCID: PMC10761173 DOI: 10.1080/19336950.2023.2200874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 04/04/2023] [Indexed: 04/12/2023] Open
Abstract
Transient receptor potential melastatin-like 7 (TRPM7) is a key player in various physiological and pathological processes. TRPM7 channel activity is regulated by different factors. The effects of cleavage of different domains on channel activity remain unknown. Here, we constructed several TRPM7 clones and explored the effects of truncating the mouse TRPM7 at different locations on the ion channel activity in two cell lines. We compared the clones' activity with the full-length TRPM7 and the native TRPM7 in transfected and untransfected cells. We also expressed fluorescently tagged truncated clones to examine their protein stability and membrane targeting. We found that truncating the kinase domain induced reduction in TRPM7 channel activity. Further truncations beyond the kinase (serine/threonine rich domain and/or coiled-coil domain) did not result in further reductions in channel activity. Two truncated clones lacking the TRP domain or the melastatin homology domain had a completely nonfunctional channel apparently due to disruption of protein stability. We identified the shortest structure of TRPM7 with measurable channel activity. We found that the truncated TRPM7 containing only S5 and S6 domains retained some channel activity. Adding the TRP domain to the S5-S6 resulted in a significant increase in channel activity. Finally, our analysis showed that TRPM7 outward currents are more sensitive to truncations than inward currents. Our data provide insights on the effects of truncating TRPM7 at different locations on the channel functions, highlighting the importance of different domains in impacting channel activity, protein stability, and/or membrane targeting.
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Affiliation(s)
- Zhuqing Xie
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Nashat Abumaria
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
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Okada Y, Numata T, Sabirov RZ, Kashio M, Merzlyak PG, Sato-Numata K. Cell death induction and protection by activation of ubiquitously expressed anion/cation channels. Part 3: the roles and properties of TRPM2 and TRPM7. Front Cell Dev Biol 2023; 11:1246955. [PMID: 37842082 PMCID: PMC10576435 DOI: 10.3389/fcell.2023.1246955] [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: 06/25/2023] [Accepted: 09/15/2023] [Indexed: 10/17/2023] Open
Abstract
Cell volume regulation (CVR) is a prerequisite for animal cells to survive and fulfill their functions. CVR dysfunction is essentially involved in the induction of cell death. In fact, sustained normotonic cell swelling and shrinkage are associated with necrosis and apoptosis, and thus called the necrotic volume increase (NVI) and the apoptotic volume decrease (AVD), respectively. Since a number of ubiquitously expressed ion channels are involved in the CVR processes, these volume-regulatory ion channels are also implicated in the NVI and AVD events. In Part 1 and Part 2 of this series of review articles, we described the roles of swelling-activated anion channels called VSOR or VRAC and acid-activated anion channels called ASOR or PAC in CVR and cell death processes. Here, Part 3 focuses on therein roles of Ca2+-permeable non-selective TRPM2 and TRPM7 cation channels activated by stress. First, we summarize their phenotypic properties and molecular structure. Second, we describe their roles in CVR. Since cell death induction is tightly coupled to dysfunction of CVR, third, we focus on their participation in the induction of or protection against cell death under oxidative, acidotoxic, excitotoxic, and ischemic conditions. In this regard, we pay attention to the sensitivity of TRPM2 and TRPM7 to a variety of stress as well as to their capability to physicall and functionally interact with other volume-related channels and membrane enzymes. Also, we summarize a large number of reports hitherto published in which TRPM2 and TRPM7 channels are shown to be involved in cell death associated with a variety of diseases or disorders, in some cases as double-edged swords. Lastly, we attempt to describe how TRPM2 and TRPM7 are organized in the ionic mechanisms leading to cell death induction and protection.
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Affiliation(s)
- Yasunobu Okada
- National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Department of Integrative Physiology, Graduate School of Medicine, AkitaUniversity, Akita, Japan
- Department of Physiology, School of Medicine, Aichi Medical Uniersity, Nagakute, Japan
- Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan
- Cardiovascular Research Institute, Yokohama City University, Yokohama, Japan
| | - Tomohiro Numata
- Department of Integrative Physiology, Graduate School of Medicine, AkitaUniversity, Akita, Japan
| | - Ravshan Z. Sabirov
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent, Uzbekistan
| | - Makiko Kashio
- National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Department of Physiology, School of Medicine, Aichi Medical Uniersity, Nagakute, Japan
| | - Peter G. Merzlyak
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent, Uzbekistan
| | - Kaori Sato-Numata
- Department of Integrative Physiology, Graduate School of Medicine, AkitaUniversity, Akita, Japan
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5
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Cheng XY, Li SF, Chen Y, Zhao YJ, Hu W, Lu C, Zhou RP. Transient receptor potential melastatin 7 and their modulators. Eur J Pharmacol 2022; 931:175180. [DOI: 10.1016/j.ejphar.2022.175180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 07/20/2022] [Accepted: 08/01/2022] [Indexed: 11/03/2022]
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6
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Schmidt E, Narangoda C, Nörenberg W, Egawa M, Rössig A, Leonhardt M, Schaefer M, Zierler S, Kurnikova MG, Gudermann T, Chubanov V. Structural mechanism of TRPM7 channel regulation by intracellular magnesium. Cell Mol Life Sci 2022; 79:225. [PMID: 35389104 PMCID: PMC8989868 DOI: 10.1007/s00018-022-04192-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/26/2022] [Accepted: 02/02/2022] [Indexed: 01/03/2023]
Abstract
Zn2+, Mg2+ and Ca2+ are essential divalent cations implicated in many metabolic processes and signalling pathways. An emerging new paradigm is that the organismal balance of these cations predominantly depends on a common gatekeeper, the channel-kinase TRPM7. Despite extensive electrophysiological studies and recent cryo-EM analysis, an open question is how the channel activity of TRPM7 is activated. Here, we performed site-directed mutagenesis of mouse TRPM7 in conjunction with patch-clamp assessment of whole-cell and single-channel activity and molecular dynamics (MD) simulations to show that the side chains of conserved N1097 form an inter-subunit Mg2+ regulatory site located in the lower channel gate of TRPM7. Our results suggest that intracellular Mg2+ binds to this site and stabilizes the TRPM7 channel in the closed state, whereas the removal of Mg2+ favours the opening of TRPM7. Hence, our study identifies the structural underpinnings through which the TRPM7 channel is controlled by cytosolic Mg2+, representing a new structure–function relationship not yet explored among TRPM channels.
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Affiliation(s)
- Eva Schmidt
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Chamali Narangoda
- Chemistry Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Wolfgang Nörenberg
- Rudolf-Boehm Institute of Pharmacology and Toxicology, Leipzig University, Leipzig, Germany
| | - Miyuki Egawa
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Anna Rössig
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Marion Leonhardt
- Rudolf-Boehm Institute of Pharmacology and Toxicology, Leipzig University, Leipzig, Germany
| | - Michael Schaefer
- Rudolf-Boehm Institute of Pharmacology and Toxicology, Leipzig University, Leipzig, Germany
| | - Susanna Zierler
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.,Institute of Pharmacology, Johannes Kepler University Linz, Linz, Austria
| | - Maria G Kurnikova
- Chemistry Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Thomas Gudermann
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany. .,Comprehensive Pneumology Center, a member of the German Center for Lung Research (DZL), Munich, Germany.
| | - Vladimir Chubanov
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.
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7
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Waixenicin A, a marine-derived TRPM7 inhibitor: a promising CNS drug lead. Acta Pharmacol Sin 2020; 41:1519-1524. [PMID: 32994545 DOI: 10.1038/s41401-020-00512-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 08/17/2020] [Indexed: 12/17/2022] Open
Abstract
Ion channels are the third largest class of targets for therapeutic drugs. The pharmacology of ion channels is an important research area for identifying new treatment options for human diseases. The past decade or so has seen increasing interest in an ion channel protein belonging to the transient receptor potential (TRP) family, namely the melastatin subfamily member 7 (TRPM7), as an emerging drug target. TRPM7 is a bifunctional protein with a magnesium and calcium-conducting divalent ion channel fused with an active kinase domain. TRPM7 is ubiquitously expressed in human tissues, including the brain, and regulates various cell biology processes such as magnesium and calcium homeostasis, cell growth and proliferation, and embryonic development. TRPM7 provides a link between cellular metabolic status and intracellular calcium homeostasis in neurons due to TRPM7's unique sensitivity to fluctuating intracellular Mg·ATP levels. Thus, the protein plays a key role in ischemic and hypoxic neuronal cell death and brain injury, and is one of the key nonglutamate mechanisms in cerebral ischemia and stroke. Currently, the most potent and specific TRPM7 inhibitor is waixenicin A, a xenicane diterpenoid from the Hawaiian soft coral Sarcothelia edmondsoni. Using waixenicin A as a pharmacological tool, we demonstrated that TRPM7 is involved in promoting neurite outgrowth in vitro. Most recently, we found that waixenicin A reduced hypoxic-ischemic brain injury and preserved long-term behavioral outcomes in mouse neonates. We here suggest that TRPM7 is an emerging drug target for CNS diseases and disorders, and waixenicin A is a viable drug lead for these disorders.
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Wong R, Gong H, Alanazi R, Bondoc A, Luck A, Sabha N, Horgen FD, Fleig A, Rutka JT, Feng ZP, Sun HS. Inhibition of TRPM7 with waixenicin A reduces glioblastoma cellular functions. Cell Calcium 2020; 92:102307. [PMID: 33080445 DOI: 10.1016/j.ceca.2020.102307] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/27/2020] [Accepted: 10/04/2020] [Indexed: 12/28/2022]
Abstract
Glioblastoma (GBM) is the most common malignant primary brain tumour originating in the CNS. Median patient survival is <15 months with standard treatment which consists of surgery alongside radiation therapy and temozolomide chemotherapy. However, because of the aggressive nature of GBM, and the significant toxicity of these adjuvant therapies, long-term therapeutic effects are unsatisfactory. Thus, there is urgency to identify new drug targets for GBM. Recent evidence shows that the transient receptor potential melastatin 7 (TRPM7) cation channel is aberrantly upregulated in GBM and its inhibition leads to reduction of GBM cellular functions. This suggests that TRPM7 may be a potential drug target for GBM treatment. In this study, we assessed the effects of the specific TRPM7 antagonist waixenicin A on human GBM cell lines U87 or U251 both in vitro and in vivo. First, we demonstrated in vitro that application of waixenicin A reduced TRPM7 protein expression and inhibited the TRPM7-like currents in GBM cells. We also observed reduction of GBM cell viability, migration, and invasion. Using an intracranial xenograft GBM mouse model, we showed that with treatment of waixenicin A, there was increased cleaved caspase 3 activity, alongside reduction in Ki-67, cofilin, and Akt activity in vivo. Together, these data demonstrate higher GBM cell apoptosis, and lower proliferation, migration, invasion and survivability following treatment with waixenicin A.
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Affiliation(s)
- Raymond Wong
- Departments of Surgery, Faculty of Medicine, University of Toronto, Toronto, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Haifan Gong
- Departments of Surgery, Faculty of Medicine, University of Toronto, Toronto, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Rahmah Alanazi
- Departments of Surgery, Faculty of Medicine, University of Toronto, Toronto, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Andrew Bondoc
- Departments of Cell Biology SickKids Research Institute, The Hospital for Sick Children, Toronto, Canada
| | - Amanda Luck
- Departments of Cell Biology SickKids Research Institute, The Hospital for Sick Children, Toronto, Canada
| | - Nesrin Sabha
- Departments of Genetics and Genome Biology, SickKids Research Institute, The Hospital for Sick Children, Toronto, Canada
| | - F David Horgen
- Department of Natural Sciences, Hawaii Pacific University, Kaneohe, Hawaii, 96744, USA
| | - Andrea Fleig
- Center for Biomedical Research at The Queen's Medical Center and John A. Burns School of Medicine at the University of Hawaii, Honolulu, Hawaii, 96720, USA
| | - James T Rutka
- Departments of Surgery, Faculty of Medicine, University of Toronto, Toronto, Canada.
| | - Zhong-Ping Feng
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada.
| | - Hong-Shuo Sun
- Departments of Surgery, Faculty of Medicine, University of Toronto, Toronto, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada; Department of Pharmacology, Faculty of Medicine, University of Toronto, Toronto, Canada; Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada.
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9
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Polat OK, Uno M, Maruyama T, Tran HN, Imamura K, Wong CF, Sakaguchi R, Ariyoshi M, Itsuki K, Ichikawa J, Morii T, Shirakawa M, Inoue R, Asanuma K, Reiser J, Tochio H, Mori Y, Mori MX. Contribution of Coiled-Coil Assembly to Ca 2+/Calmodulin-Dependent Inactivation of TRPC6 Channel and its Impacts on FSGS-Associated Phenotypes. J Am Soc Nephrol 2019; 30:1587-1603. [PMID: 31266820 DOI: 10.1681/asn.2018070756] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 04/23/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND TRPC6 is a nonselective cation channel, and mutations of this gene are associated with FSGS. These mutations are associated with TRPC6 current amplitude amplification and/or delay of the channel inactivation (gain-of-function phenotype). However, the mechanism of the gain-of-function in TRPC6 activity has not yet been clearly solved. METHODS We performed electrophysiologic, biochemical, and biophysical experiments to elucidate the molecular mechanism underlying calmodulin (CaM)-mediated Ca2+-dependent inactivation (CDI) of TRPC6. To address the pathophysiologic contribution of CDI, we assessed the actin filament organization in cultured mouse podocytes. RESULTS Both lobes of CaM helped induce CDI. Moreover, CaM binding to the TRPC6 CaM-binding domain (CBD) was Ca2+-dependent and exhibited a 1:2 (CaM/CBD) stoichiometry. The TRPC6 coiled-coil assembly, which brought two CBDs into adequate proximity, was essential for CDI. Deletion of the coiled-coil slowed CDI of TRPC6, indicating that the coiled-coil assembly configures both lobes of CaM binding on two CBDs to induce normal CDI. The FSGS-associated TRPC6 mutations within the coiled-coil severely delayed CDI and often increased TRPC6 current amplitudes. In cultured mouse podocytes, FSGS-associated channels and CaM mutations led to sustained Ca2+ elevations and a disorganized cytoskeleton. CONCLUSIONS The gain-of-function mechanism found in FSGS-causing mutations in TRPC6 can be explained by impairments of the CDI, caused by disruptions of TRPC's coiled-coil assembly which is essential for CaM binding. The resulting excess Ca2+ may contribute to structural damage in the podocytes.
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Affiliation(s)
- Onur K Polat
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering
| | - Masatoshi Uno
- Department of Biophysics, Graduate School of Science.,Department of Molecular Engineering, Graduate School of Engineering
| | - Terukazu Maruyama
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering
| | - Ha Nam Tran
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering.,Department of Technology and Ecology, Laboratory of Environmental Systems Biology, Graduate School of Global Environmental Studies
| | - Kayo Imamura
- Department of Biophysics, Graduate School of Science
| | - Chee Fah Wong
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering.,Department of Biology, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, Perak, Malaysia
| | - Reiko Sakaguchi
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering.,Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto, Japan
| | - Mariko Ariyoshi
- Department of Molecular Engineering, Graduate School of Engineering
| | - Kyohei Itsuki
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Jun Ichikawa
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Takashi Morii
- Institute of Advanced Energy, Kyoto University, Kyoto, Japan
| | | | - Ryuji Inoue
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Katsuhiko Asanuma
- Department of Nephrology, School of Medicine, Chiba University, Chiba, Japan
| | - Jochen Reiser
- Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | | | - Yasuo Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering
| | - Masayuki X Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering,
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10
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Redox TRPs in diabetes and diabetic complications: Mechanisms and pharmacological modulation. Pharmacol Res 2019; 146:104271. [PMID: 31096011 DOI: 10.1016/j.phrs.2019.104271] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 04/04/2019] [Accepted: 05/08/2019] [Indexed: 12/12/2022]
Abstract
Transient receptor potential (TRP) channels have shown to be involved in a wide variety of physiological functions and pathophysiological conditions. Modulation of TRP channels reported to play a major role in number of disorders starting from central nervous system related disorders to cardiovascular, inflammatory, cancer, gastrointestinal and metabolic diseases. Recently, a subset of TRP ion channels called redox TRPs gained importance on account of their ability to sense the cellular redox environment and respond accordingly to such redox stimuli. Diabetes, the silent epidemic of the world is increasing at an alarming rate in spite of novel therapeutic interventions. Moreover, diabetes and its associated complications are reported to arise due to a change in oxidative status of cell induced by hyperglycemia. Such a change in cellular oxidative status can modulate the activities of various redox TRP channels (TRPA1, TRPC5, TRPMs and TRPV1). Targeting redox TRPs have potential in diabetes and diabetic complications like neuropathy, cardiomyopathy, retinopathy, cystopathy, and encephalopathy. Thus in this review, we have discussed the activities of different redox sensing TRPs in diabetes and diabetic complications and how they can be modulated pharmacologically, so as to consider them a potential novel therapeutic target in treating diabetes and its comorbidity.
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11
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Broertjes J, Klarenbeek J, Habani Y, Langeslag M, Jalink K. TRPM7 residue S1269 mediates cAMP dependence of Ca2+ influx. PLoS One 2019; 14:e0209563. [PMID: 30615643 PMCID: PMC6322742 DOI: 10.1371/journal.pone.0209563] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 12/07/2018] [Indexed: 02/06/2023] Open
Abstract
The nonspecific divalent cation channel TRPM7 (transient receptor potential-melastatin-like 7) is involved in many Ca2+ and Mg2+-dependent cellular processes, including survival, proliferation and migration. TRPM7 expression predicts metastasis and recurrence in breast cancer and several other cancers. In cultured cells, it can induce an invasive phenotype by promoting Ca2+-mediated epithelial-mesenchymal transition. We previously showed that in neuroblastoma cells that overexpress TRPM7 moderately, stimulation with Ca2+-mobilizing agonists leads to a characteristic sustained influx of Ca2+. Here we report that sustained influx through TRPM7 is abruptly abrogated by elevating intracellular levels of cyclic adenosine monophosphate (cAMP). Using pharmacological inhibitors and overexpression studies we show that this blockage is mediated by the cAMP effector Protein Kinase A (PKA). Mutational analysis demonstrates that the Serine residue S1269, which is present proximal to the coiled-coil domain within the protein c-terminus, is responsible for sensitivity to cAMP.
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Affiliation(s)
- Jorrit Broertjes
- Division of Cell Biology I, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Jeffrey Klarenbeek
- Division of Cell Biology I, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Yasmin Habani
- Division of Cell Biology I, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Michiel Langeslag
- Division of Cell Biology I, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Kees Jalink
- Division of Cell Biology I, The Netherlands Cancer Institute, Amsterdam, The Netherlands
- * E-mail:
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12
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Chubanov V, Mittermeier L, Gudermann T. TRPM7 reflected in Cryo-EMirror. Cell Calcium 2018; 76:129-131. [PMID: 30470536 DOI: 10.1016/j.ceca.2018.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 11/13/2018] [Accepted: 11/13/2018] [Indexed: 10/27/2022]
Abstract
TRPM7 is an atypical type of ion channel because its pore-forming moiety is covalently linked to a protein kinase domain. The channel-kinase TRPM7 controls a wide range of biological processes such as mineral homeostasis, immune responses, cell motility, proliferation and differentiation. Earlier this year, Duan J & co-workers [1] published three TRPM7 structures resolved by cryo-electron microscopy (cryo-EM). This study tremendously advances our mechanistic understanding of TRPM7 channel function and forms the basis for informed structure-function assessment of this extraordinary protein.
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Affiliation(s)
- Vladimir Chubanov
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Germany.
| | - Lorenz Mittermeier
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Germany; German Center for Lung Research, Munich, Germany; German Centre for Cardiovascular Research, Munich Heart Alliance, Munich, Germany.
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13
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14
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Komiya Y, Bai Z, Cai N, Lou L, Al-Saadi N, Mezzacappa C, Habas R, Runnels LW. A Nonredundant Role for the TRPM6 Channel in Neural Tube Closure. Sci Rep 2017; 7:15623. [PMID: 29142255 PMCID: PMC5688082 DOI: 10.1038/s41598-017-15855-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 10/19/2017] [Indexed: 01/17/2023] Open
Abstract
In humans, germline mutations in Trpm6 cause autosomal dominant hypomagnesemia with secondary hypocalcemia disorder. Loss of Trpm6 in mice also perturbs cellular magnesium homeostasis but additionally results in early embryonic lethality and neural tube closure defects. To define the mechanisms by which TRPM6 influences neural tube closure, we functionally characterized the role of TRPM6 during early embryogenesis in Xenopus laevis. The expression of Xenopus TRPM6 (XTRPM6) is elevated at the onset of gastrulation and is concentrated in the lateral mesoderm and ectoderm at the neurula stage. Loss of XTRPM6 produced gastrulation and neural tube closure defects. Unlike XTRPM6's close homologue XTRPM7, whose loss interferes with mediolateral intercalation, depletion of XTRPM6 but not XTRPM7 disrupted radial intercalation cell movements. A zinc-influx assay demonstrated that TRPM6 has the potential to constitute functional channels in the absence of TRPM7. The results of our study indicate that XTRPM6 regulates radial intercalation with little or no contribution from XTRPM7 in the region lateral to the neural plate, whereas XTRPM7 is mainly involved in regulating mediolateral intercalation in the medial region of the neural plate. We conclude that both TRPM6 and TRPM7 channels function cooperatively but have distinct and essential roles during neural tube closure.
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Affiliation(s)
- Yuko Komiya
- Rutgers-Robert Wood Johnson Medical School, Deptartment of Pharmacology, Piscataway, 08854, USA.
| | - Zhiyong Bai
- Rutgers-Robert Wood Johnson Medical School, Deptartment of Pharmacology, Piscataway, 08854, USA
| | - Na Cai
- Rutgers-Robert Wood Johnson Medical School, Deptartment of Pharmacology, Piscataway, 08854, USA
| | - Liping Lou
- Rutgers-Robert Wood Johnson Medical School, Deptartment of Pharmacology, Piscataway, 08854, USA
| | - Namariq Al-Saadi
- Rutgers-Robert Wood Johnson Medical School, Deptartment of Pharmacology, Piscataway, 08854, USA
| | | | - Raymond Habas
- Temple University, Deptartment of Biology, Philadelphia, 19122, USA.
| | - Loren W Runnels
- Rutgers-Robert Wood Johnson Medical School, Deptartment of Pharmacology, Piscataway, 08854, USA.
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15
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Assessment of TRPM7 functions by drug-like small molecules. Cell Calcium 2017; 67:166-173. [DOI: 10.1016/j.ceca.2017.03.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 03/08/2017] [Indexed: 12/28/2022]
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16
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Kühn F, Kühn C, Lückhoff A. Different Principles of ADP-Ribose-Mediated Activation and Opposite Roles of the NUDT9 Homology Domain in the TRPM2 Orthologs of Man and Sea Anemone. Front Physiol 2017; 8:879. [PMID: 29163217 PMCID: PMC5671594 DOI: 10.3389/fphys.2017.00879] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/18/2017] [Indexed: 01/31/2023] Open
Abstract
A decisive element in the human cation channel TRPM2 is a region in its cytosolic C-terminus named NUDT9H because of its homology to the NUDT9 enzyme, a pyrophosphatase degrading ADP-ribose (ADPR). In hTRPM2, however, the NUDT9H domain has lost its enzymatic activity but serves as a binding domain for ADPR. As consequence of binding, gating of the channel is initiated. Since ADPR is produced after oxidative DNA damage, hTRPM2 mediates Ca2+ influx in response to oxidative stress which may lead to cell death. In the genome of the sea anemone Nematostella vectensis (nv), a preferred model organism for the evolution of key bilaterian features, a TRPM2 ortholog has been identified that contains a NUDT9H domain as well. Heterologous expression of nvTRPM2 in HEK-293 cells reveals a cation channel with many close similarities to the human counterpart. Most notably, nvTRPM2 is activated by ADPR, and Ca2+ is a co-agonist. However, the intramolecular mechanisms of ADPR gating as well as the role of NUDT9H are strikingly different in the two species. Whereas already subtle changes of NUDT9H abolish ADPR gating in hTRPM2, the region can be completely removed from nvTRPM2 without loss of responses to ADPR. An alternative ADPR binding site seems to be present but has not yet been characterized. The ADP-ribose pyrophosphatase (ADPRase) function of nvNUDT9H has been preserved but can be abolished by numerous genetic manipulations. All these manipulations create channels that are sensitive to hydrogen peroxide which fails to induce channel activity in wild-type nvTRPM2. Therefore, the function of NUDT9H in nvTRPM2 is the degradation of ADPR, thereby reducing agonist concentration in the presence of oxidative stress. Thus, the two TRPM2 orthologs have evolved divergently but nevertheless gained analogous functional properties, i.e., gating by ADPR with Ca2+ as co-factor. Opposite roles are played by the respective NUDT9H domains, either binding of ADPR and mediating channel activity, or controlling the availability of ADPR at the binding site located in a different domain.
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Affiliation(s)
- Frank Kühn
- Medical Faculty, Institute of Physiology, RWTH Aachen University, Aachen, Germany
| | - Cornelia Kühn
- Medical Faculty, Institute of Physiology, RWTH Aachen University, Aachen, Germany
| | - Andreas Lückhoff
- Medical Faculty, Institute of Physiology, RWTH Aachen University, Aachen, Germany
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17
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Ferioli S, Zierler S, Zaißerer J, Schredelseker J, Gudermann T, Chubanov V. TRPM6 and TRPM7 differentially contribute to the relief of heteromeric TRPM6/7 channels from inhibition by cytosolic Mg 2+ and Mg·ATP. Sci Rep 2017; 7:8806. [PMID: 28821869 PMCID: PMC5562840 DOI: 10.1038/s41598-017-08144-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 07/05/2017] [Indexed: 02/04/2023] Open
Abstract
TRPM6 and its homologue TRPM7 are α-kinase-coupled divalent cation-selective channels activated upon reduction of cytosolic levels of Mg2+ and Mg·ATP. TRPM6 is vital for organismal Mg2+ balance. However, mechanistically the cellular role and functional nonredundancy of TRPM6 remain incompletely understood. Comparative analysis of native currents in primary cells from TRPM6- versus TRPM7-deficient mice supported the concept that native TRPM6 primarily functions as a constituent of heteromeric TRPM6/7 channels. However, heterologous expression of the human TRPM6 protein engendered controversial results with respect to channel characteristics including its regulation by Mg2+ and Mg·ATP. To resolve this issue, we cloned the mouse TRPM6 (mTRPM6) cDNA and compared its functional characteristics to mouse TRPM7 (mTRPM7) after heterologous expression. Notably, we observed that mTRPM6 and mTRPM7 differentially regulate properties of heteromeric mTRPM6/7 channels: In the presence of mTRPM7, the extreme sensitivity of functionally expressed homomeric mTRPM6 to Mg2+ is tuned to higher concentrations, whereas mTRPM6 relieves mTRPM7 from the tight inhibition by Mg·ATP. Consequently, the association of mTRPM6 with mTRPM7 allows for high constitutive activity of mTRPM6/7 in the presence of physiological levels of Mg2+ and Mg·ATP, thus laying the mechanistic foundation for constant vectorial Mg2+ transport specifically into epithelial cells.
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Affiliation(s)
- Silvia Ferioli
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Susanna Zierler
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Joanna Zaißerer
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Johann Schredelseker
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany. .,German Center for Lung Research, Munich, Germany. .,German Centre for Cardiovascular Research, Munich Heart Alliance, Munich, Germany.
| | - Vladimir Chubanov
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.
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18
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Kühn FJP, Mathis W, Cornelia K, Hoffmann DC, Lückhoff A. Modulation of activation and inactivation by Ca 2+ and 2-APB in the pore of an archetypal TRPM channel from Nematostella vectensis. Sci Rep 2017; 7:7245. [PMID: 28775320 PMCID: PMC5543165 DOI: 10.1038/s41598-017-07652-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 06/06/2017] [Indexed: 12/19/2022] Open
Abstract
The archetypal TRPM2-like channel of the sea anemone Nematostella vectensis is gated by ADPR like its human orthologue but additionally exhibits properties of other vertebrate TRPM channels. Thus it can help towards an understanding of gating and regulation of the whole subfamily. To elucidate further the role of Ca2+ as a co-factor of ADPR, we exploited 2-aminoethyl diphenylborinate (2-APB), previously shown to exert either inhibitory or stimulatory effects on diverse TRPM channels, or both in a concentration-dependent manner. 2-APB in high concentrations (1 mM) induced large, non-inactivating currents through nvTRPM2. In lower concentrations (≤0.5 mM), it prevented the fast current inactivation typical for nvTRPM2 stimulated with ADPR. Both these effects were rapidly reversed after wash-out of 2-APB, in contrast to a considerable lag time of their onset. A detailed analysis of nvTRPM2 mutants with modified selectivity filter or reduced ADP-ribose sensitivity revealed that the actions of 2-APB depend on its access to the pore which is enhanced by channel opening. Moreover, access of Ca2+ to the pore is decisive which again depends on the open state of the channel. We conclude that separate regulatory processes by Ca2+ on the pore can be discriminated with the aid of 2-APB.
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Affiliation(s)
- Frank J P Kühn
- Institute of Physiology, Medical Faculty, RWTH Aachen, D52057, Aachen, Germany.
| | - Winking Mathis
- Institute of Physiology, Medical Faculty, RWTH Aachen, D52057, Aachen, Germany
| | - Kühn Cornelia
- Institute of Physiology, Medical Faculty, RWTH Aachen, D52057, Aachen, Germany
| | - Daniel C Hoffmann
- Institute of Physiology, Medical Faculty, RWTH Aachen, D52057, Aachen, Germany
| | - Andreas Lückhoff
- Institute of Physiology, Medical Faculty, RWTH Aachen, D52057, Aachen, Germany
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Faouzi M, Kilch T, Horgen FD, Fleig A, Penner R. The TRPM7 channel kinase regulates store-operated calcium entry. J Physiol 2017; 595:3165-3180. [PMID: 28130783 DOI: 10.1113/jp274006] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 01/20/2017] [Indexed: 12/11/2022] Open
Abstract
KEY POINTS Pharmacological and molecular inhibition of transient receptor potential melastatin 7 (TRPM7) reduces store-operated calcium entry (SOCE). Overexpression of TRPM7 in TRPM7-/- cells restores SOCE. TRPM7 is not a store-operated calcium channel. TRPM7 kinase rather than channel modulates SOCE. TRPM7 channel activity contributes to the maintenance of store Ca2+ levels at rest. ABSTRACT The transient receptor potential melastatin 7 (TRPM7) is a protein that combines an ion channel with an intrinsic kinase domain, enabling it to modulate cellular functions either by conducting ions through the pore or by phosphorylating downstream proteins via its kinase domain. In the present study, we report store-operated calcium entry (SOCE) as a novel target of TRPM7 kinase activity. TRPM7-deficient chicken DT40 B lymphocytes exhibit a strongly impaired SOCE compared to wild-type cells as a result of reduced calcium release activated calcium currents, and independently of potassium channel regulation, membrane potential changes or changes in cell-cycle distribution. Pharmacological blockade of TRPM7 with NS8593 or waixenicin A in wild-type B lymphocytes results in a significant decrease in SOCE, confirming that TRPM7 activity is acutely linked to SOCE, without TRPM7 representing a store-operated channel itself. Using kinase-deficient mutants, we find that TRPM7 regulates SOCE through its kinase domain. Furthermore, Ca2+ influx through TRPM7 is essential for the maintenance of endoplasmic reticulum Ca2+ concentration in resting cells, and for the refilling of Ca2+ stores after a Ca2+ signalling event. We conclude that the channel kinase TRPM7 and SOCE are synergistic mechanisms regulating intracellular Ca2+ homeostasis.
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Affiliation(s)
- Malika Faouzi
- Centre for Biomedical Research, The Queen's Medical Centre, University of Hawaii Cancer Centre and John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| | - Tatiana Kilch
- Centre for Biomedical Research, The Queen's Medical Centre, University of Hawaii Cancer Centre and John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| | - F David Horgen
- Laboratory of Marine Biological Chemistry, Department of Natural Sciences, Hawaii Pacific University, Kaneohe, HI, USA
| | - Andrea Fleig
- Centre for Biomedical Research, The Queen's Medical Centre, University of Hawaii Cancer Centre and John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| | - Reinhold Penner
- Centre for Biomedical Research, The Queen's Medical Centre, University of Hawaii Cancer Centre and John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
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