1
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Gattkowski E, Rutherford TJ, Möckl F, Bauche A, Sander S, Fliegert R, Tidow H. Analysis of ligand binding and resulting conformational changes in pyrophosphatase NUDT9. FEBS J 2021; 288:6769-6782. [PMID: 34189846 PMCID: PMC7612441 DOI: 10.1111/febs.16097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 06/04/2021] [Accepted: 06/29/2021] [Indexed: 11/29/2022]
Abstract
Nudix hydrolase 9 (NUDT9) is a member of the nucleoside linked to another moiety X (NUDIX) protein superfamily, which hydrolyses a broad spectrum of organic pyrophosphates from metabolic processes. ADP‐ribose (ADPR) has been the only known endogenous substrate accepted by NUDT9 so far. The Ca2+‐permeable transient receptor potential melastatin subfamily 2 (TRPM2) channel contains a homologous NUDT9‐homology (NUDT9H) domain and is activated by ADPR. Sustained Ca2+ influx via ADPR‐activated TRPM2 triggers apoptotic mechanisms. Thus, a precise regulation of cellular ADPR levels by NUDT9 is essential. A detailed characterization of the enzyme‐substrate interaction would help to understand the high substrate specificity of NUDT9. Here, we analysed ligand binding to NUDT9 using a variety of biophysical techniques. We identified 2′‐deoxy‐ADPR as an additional substrate for NUDT9. Similar enzyme kinetics and binding affinities were determined for the two ligands. The high‐affinity binding was preserved in NUDT9 containing the mutated NUDIX box derived from the human NUDT9H domain. NMR spectroscopy indicated that ADPR and 2′‐deoxy‐ADPR bind to the same binding site of NUDT9. Backbone resonance assignment and subsequent molecular docking allowed further characterization of the binding pocket. Substantial conformational changes of NUDT9 upon ligand binding were observed which might allow for the development of NUDT9‐based ADPR fluorescence resonance energy transfer sensors that may help with the analysis of ADPR signalling processes in cells in the future.
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Affiliation(s)
- Ellen Gattkowski
- The Hamburg Advanced Research Center for Bioorganic Chemistry (HARBOR) & Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Germany
| | | | - Franziska Möckl
- Department of Biochemistry and Molecular Cell Biology, University Medical Centre Hamburg-Eppendorf, Germany
| | - Andreas Bauche
- Department of Biochemistry and Molecular Cell Biology, University Medical Centre Hamburg-Eppendorf, Germany
| | - Simon Sander
- The Hamburg Advanced Research Center for Bioorganic Chemistry (HARBOR) & Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Germany
| | - Ralf Fliegert
- Department of Biochemistry and Molecular Cell Biology, University Medical Centre Hamburg-Eppendorf, Germany
| | - Henning Tidow
- The Hamburg Advanced Research Center for Bioorganic Chemistry (HARBOR) & Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Germany
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2
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Tóth B, Iordanov I, Csanády L. Selective profiling of N- and C-terminal nucleotide-binding sites in a TRPM2 channel. J Gen Physiol 2021; 152:151583. [PMID: 32211872 PMCID: PMC7201885 DOI: 10.1085/jgp.201912533] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/20/2020] [Indexed: 11/23/2022] Open
Abstract
Transient receptor potential melastatin 2 (TRPM2) is a homotetrameric Ca2+-permeable cation channel important for the immune response, body temperature regulation, and insulin secretion, and is activated by cytosolic Ca2+ and ADP ribose (ADPR). ADPR binds to two distinct locations, formed by large N- and C-terminal cytosolic domains, respectively, of the channel protein. In invertebrate TRPM2 channels, the C-terminal site is not required for channel activity but acts as an active ADPR phosphohydrolase that cleaves the activating ligand. In vertebrate TRPM2 channels, the C-terminal site is catalytically inactive but cooperates with the N-terminal site in channel activation. The precise functional contributions to channel gating and the nucleotide selectivities of the two sites in various species have not yet been deciphered. For TRPM2 of the sea anemone Nematostella vectensis (nvTRPM2), catalytic activity is solely attributable to the C-terminal site. Here, we show that nvTRPM2 channel gating properties remain unaltered upon deletion of the C-terminal domain, indicating that the N-terminal site is single-handedly responsible for channel gating. Exploiting such functional independence of the N- and C-terminal sites, we selectively measure their affinity profiles for a series of ADPR analogues, as reflected by apparent affinities for channel activation and catalysis, respectively. Using site-directed mutagenesis, we confirm that the same N-terminal site observed in vertebrate TRPM2 channels was already present in ancient cnidarians. Finally, by characterizing the functional effects of six amino acid side chain truncations in the N-terminal site, we provide first insights into the mechanistic contributions of those side chains to TRPM2 channel gating.
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Affiliation(s)
- Balázs Tóth
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary.,MTA-SE Lendület Ion Channel Research Group, Semmelweis University, Budapest, Hungary
| | - Iordan Iordanov
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary.,MTA-SE Lendület Ion Channel Research Group, Semmelweis University, Budapest, Hungary
| | - László Csanády
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary.,MTA-SE Lendület Ion Channel Research Group, Semmelweis University, Budapest, Hungary
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3
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Species-Specific Regulation of TRPM2 by PI(4,5)P 2 via the Membrane Interfacial Cavity. Int J Mol Sci 2021; 22:ijms22094637. [PMID: 33924946 PMCID: PMC8125603 DOI: 10.3390/ijms22094637] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/21/2021] [Accepted: 04/26/2021] [Indexed: 12/13/2022] Open
Abstract
The human apoptosis channel TRPM2 is stimulated by intracellular ADR-ribose and calcium. Recent studies show pronounced species-specific activation mechanisms. Our aim was to analyse the functional effect of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), commonly referred to as PIP2, on different TRPM2 orthologues. Moreover, we wished to identify the interaction site between TRPM2 and PIP2. We demonstrate a crucial role of PIP2, in the activation of TRPM2 orthologues of man, zebrafish, and sea anemone. Utilizing inside-out patch clamp recordings of HEK-293 cells transfected with TRPM2, differential effects of PIP2 that were dependent on the species variant became apparent. While depletion of PIP2 via polylysine uniformly caused complete inactivation of TRPM2, restoration of channel activity by artificial PIP2 differed widely. Human TRPM2 was the least sensitive species variant, making it the most susceptible one for regulation by changes in intramembranous PIP2 content. Furthermore, mutations of highly conserved positively charged amino acid residues in the membrane interfacial cavity reduced the PIP2 sensitivity in all three TRPM2 orthologues to varying degrees. We conclude that the membrane interfacial cavity acts as a uniform PIP2 binding site of TRPM2, facilitating channel activation in the presence of ADPR and Ca2+ in a species-specific manner.
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4
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Two Decades of Evolution of Our Understanding of the Transient Receptor Potential Melastatin 2 (TRPM2) Cation Channel. Life (Basel) 2021; 11:life11050397. [PMID: 33925466 PMCID: PMC8145809 DOI: 10.3390/life11050397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 02/07/2023] Open
Abstract
The transient receptor potential melastatin (TRPM) family belongs to the superfamily of TRP ion channels. It consists of eight family members that are involved in a plethora of cellular functions. TRPM2 is a homotetrameric Ca2+-permeable cation channel activated upon oxidative stress and is important, among others, for body heat control, immune cell activation and insulin secretion. Invertebrate TRPM2 proteins are channel enzymes; they hydrolyze the activating ligand, ADP-ribose, which is likely important for functional regulation. Since its cloning in 1998, the understanding of the biophysical properties of the channel has greatly advanced due to a vast number of structure–function studies. The physiological regulators of the channel have been identified and characterized in cell-free systems. In the wake of the recent structural biochemistry revolution, several TRPM2 cryo-EM structures have been published. These structures have helped to understand the general features of the channel, but at the same time have revealed unexplained mechanistic differences among channel orthologues. The present review aims at depicting the major research lines in TRPM2 structure-function. It discusses biophysical properties of the pore and the mode of action of direct channel effectors, and interprets these functional properties on the basis of recent three-dimensional structural models.
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5
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Yu P, Cai X, Liang Y, Wang M, Yang W. Roles of NAD + and Its Metabolites Regulated Calcium Channels in Cancer. Molecules 2020; 25:molecules25204826. [PMID: 33092205 PMCID: PMC7587972 DOI: 10.3390/molecules25204826] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/11/2020] [Accepted: 10/16/2020] [Indexed: 02/08/2023] Open
Abstract
Nicotinamide adenine dinucleotide (NAD+) is an essential cofactor for redox enzymes, but also moonlights as a regulator for ion channels, the same as its metabolites. Ca2+ homeostasis is dysregulated in cancer cells and affects processes such as tumorigenesis, angiogenesis, autophagy, progression, and metastasis. Herein, we summarize the regulation of the most common calcium channels (TRPM2, TPCs, RyRs, and TRPML1) by NAD+ and its metabolites, with a particular focus on their roles in cancers. Although the mechanisms of NAD+ metabolites in these pathological processes are yet to be clearly elucidated, these ion channels are emerging as potential candidates of alternative targets for anticancer therapy.
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Affiliation(s)
- Peilin Yu
- Department of Toxicology, and Department of Medical Oncology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China; (P.Y.); (Y.L.)
| | - Xiaobo Cai
- Department of Biophysics, and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China;
| | - Yan Liang
- Department of Toxicology, and Department of Medical Oncology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China; (P.Y.); (Y.L.)
| | - Mingxiang Wang
- BrioPryme Biologics, Inc., Hangzhou 310058, Zhejiang, China;
| | - Wei Yang
- Department of Biophysics, and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China;
- Correspondence: ; Tel.: +86-571-8820-8713
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6
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Structure-Function Relationship of TRPM2: Recent Advances, Contradictions, and Open Questions. Int J Mol Sci 2020; 21:ijms21186481. [PMID: 32899872 PMCID: PMC7555694 DOI: 10.3390/ijms21186481] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/25/2020] [Accepted: 09/03/2020] [Indexed: 12/21/2022] Open
Abstract
When in a particular scientific field, major progress is rapidly reached after a long period of relative stand-still, this is often achieved by the development or exploitation of new techniques and methods. A striking example is the new insights brought into the understanding of the gating mechanism of the transient receptor potential melastatin type 2 cation channel (TRPM2) by cryogenic electron microscopy structure analysis. When conventional methods are complemented by new ones, it is quite natural that established researchers are not fully familiar with the possibilities and limitations of the new method. On the other hand, newcomers may need some assistance in perceiving the previous knowledge in detail; they may not realize that some of their interpretations are at odds with previous results and need refinement. This may in turn trigger further studies with new and promising perspectives, combining the promises of several methodological approaches. With this review, I aim to give a comprehensive overview on functional data of several orthologous of TRPM2 that are nicely explained by structural studies. Moreover, I wish to point out some functional contradictions raised by the structural data. Finally, some open questions and some lines of possible future experimental approaches shall be discussed.
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7
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Fliegert R, Riekehr WM, Guse AH. Does Cyclic ADP-Ribose (cADPR) Activate the Non-selective Cation Channel TRPM2? Front Immunol 2020; 11:2018. [PMID: 32903769 PMCID: PMC7438885 DOI: 10.3389/fimmu.2020.02018] [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: 04/01/2020] [Accepted: 07/24/2020] [Indexed: 12/18/2022] Open
Abstract
TRPM2 is a non-selective, Ca2+-permeable cation channel widely expressed in immune cells. It is firmly established that the channel can be activated by intracellular adenosine 5′-diphosphoribose (ADPR). Until recent cryo-EM structures have exhibited an additional nucleotide binding site in the N-terminus of the channel, this activation was thought to occur via binding to a C-terminal domain of the channel that is highly homologous to the ADPR pyrophosphatase NudT9. Over the years it has been controversially discussed whether the Ca2+ mobilizing second messenger cyclic ADP ribose (cADPR) might also directly activate Ca2+ entry via TRPM2. Here we will review the status of this discussion.
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Affiliation(s)
- Ralf Fliegert
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Winnie M Riekehr
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andreas H Guse
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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8
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Wang L, Negro R, Wu H. TRPM2, linking oxidative stress and Ca 2+ permeation to NLRP3 inflammasome activation. Curr Opin Immunol 2020; 62:131-135. [PMID: 32058297 DOI: 10.1016/j.coi.2020.01.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 12/12/2022]
Abstract
The NLRP3 inflammasome is an innate immune platform that senses various pathogens and sterile insults. NLRP3 stimulation leads to activation of caspase-1, the secretion of pro-inflammatory cytokines and an inflammatory cell death called pyroptosis. Effectors of the NLRP3 inflammasome efficiently drive an immune response, not only providing protection in physiological settings but also promoting pathology when over activated. Generation of reactive oxygen species (ROS) and intracellular calcium mobilization can activate the NLRP3 inflammasome. Recent studies suggest that TRPM2 is a calcium-permeable cation channel mediating ROS-dependent NLRP3 activation. Here, we review the role of TRPM2 in NLRP3 inflammasome activation and provide an update on new functional and structural discoveries. Understanding the molecular mechanism of TRPM2 dependent NLRP3 inflammasome activation will shed lights on this complex pathway and help the developing of therapeutic strategies.
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Affiliation(s)
- Longfei Wang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, and Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Roberto Negro
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, and Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Hao Wu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, and Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA.
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9
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Baszczyňski O, Watt JM, Rozewitz MD, Fliegert R, Guse AH, Potter BVL. Synthesis of phosphonoacetate analogues of the second messenger adenosine 5'-diphosphate ribose (ADPR). RSC Adv 2020; 10:1776-1785. [PMID: 31934327 PMCID: PMC6957348 DOI: 10.1039/c9ra09284f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Adenosine 5′-diphosphate ribose (ADPR) is an intracellular signalling molecule generated from nicotinamide adenine dinucleotide (NAD+). Synthetic ADPR analogues can shed light on the mechanism of activation of ADPR targets and their downstream effects. Such chemical biology studies, however, are often challenging due to the negatively charged pyrophosphate that is also sensitive to cellular pyrophosphatases. Prior work on an initial ADPR target, the transient receptor potential cation channel TRPM2, showed complete pyrophosphate group replacement to be a step too far in maintaining biological activity. Thus, we designed ADPR analogues with just one of the negatively charged phosphate groups removed, by employing a phosphonoacetate linker. Synthesis of two novel phosphonoacetate ADPR analogues is described via tandem N,N′-dicyclohexylcarbodiimide coupling to phosphonoacetic acid. Neither analogue, however, showed significant agonist or antagonist activity towards TRPM2, underlining the importance of a complete pyrophosphate motif in activation of this particular receptor. Pyrophosphate replacement using phosphonoacetate isosteres – tools to study biological targets of ADPR.![]()
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Affiliation(s)
- Ondřej Baszczyňski
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Bath, BA2 7AY, UK
| | - Joanna M Watt
- Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.,Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Bath, BA2 7AY, UK
| | - Monika D Rozewitz
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Ralf Fliegert
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Andreas H Guse
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Barry V L Potter
- Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.,Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Bath, BA2 7AY, UK
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10
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Functional importance of NUDT9H domain and N-terminal ADPR-binding pocket in two species variants of vertebrate TRPM2 channels. Sci Rep 2019; 9:19224. [PMID: 31844070 PMCID: PMC6914804 DOI: 10.1038/s41598-019-55232-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 11/25/2019] [Indexed: 12/22/2022] Open
Abstract
There are at least two different principles of how ADP-ribose (ADPR) induces activation of TRPM2 channels. In human TRPM2, gating requires the C-terminal NUDT9H domain as ADPR-binding module, whereas in sea anemone, NUDT9H is dispensable and binding of ADPR occurs N-terminally. Zebrafish TRPM2 needs both, the N-terminal ADPR-binding pocket and NUDT9H. Our aim was to pinpoint the relative functional contributions of NUDT9H and the N-terminal ADPR-binding pocket in zebrafish TRPM2, to identify fundamental mechanisms of ADPR-directed gating. We show that the NUDT9H domains of human and zebrafish TRPM2 are interchangeable since chimeras generate ADPR-sensitive channels. A point mutation at a highly conserved position within NUDT9H induces loss-of-function in both vertebrate channels. The substrate specificity of zebrafish TRPM2 corresponds to that of sea anemone TRPM2, indicating gating by the proposed N-terminal ADPR-binding pocket. However, a point mutation in this region abolishes ADPR activation also in human TRPM2. These findings provide functional evidence for an uniform N-terminal ADPR-binding pocket in TRPM2 of zebrafish and sea anemone with modified function in human TRPM2. The structural importance of NUDT9H in vertebrate TRPM2 can be associated with a single amino acid residue which is not directly involved in the binding of ADPR.
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11
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A structural overview of the ion channels of the TRPM family. Cell Calcium 2019; 85:102111. [PMID: 31812825 DOI: 10.1016/j.ceca.2019.102111] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 12/20/2022]
Abstract
The TRPM (transient receptor potential melastatin) family belongs to the superfamily of TRP cation channels. The TRPM subfamily is composed of eight members that are involved in diverse biological functions such as temperature sensing, inflammation, insulin secretion, and redox sensing. Since the first cloning of TRPM1 in 1998, tremendous progress has been made uncovering the function, structure, and pharmacology of this family. Complete structures of TRPM2, TRPM4, and TRPM8, as well as a partial structure of TRPM7, have been determined by cryo-EM, providing insights into their channel assembly, ion permeation, gating mechanisms, and structural pharmacology. Here we summarize the current knowledge about channel structure, emphasizing general features and principles of the structure of TRPM channels discovered since 2017. We also discuss some of the key unresolved issues in the field, including the molecular mechanisms underlying voltage and temperature dependence, as well as the functions of the TRPM channels' C-terminal domains.
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12
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Huang Y, Roth B, Lü W, Du J. Ligand recognition and gating mechanism through three ligand-binding sites of human TRPM2 channel. eLife 2019; 8:50175. [PMID: 31513012 PMCID: PMC6759353 DOI: 10.7554/elife.50175] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 09/11/2019] [Indexed: 12/17/2022] Open
Abstract
TRPM2 is critically involved in diverse physiological processes including core temperature sensing, apoptosis, and immune response. TRPM2’s activation by Ca2+ and ADP ribose (ADPR), an NAD+-metabolite produced under oxidative stress and neurodegenerative conditions, suggests a role in neurological disorders. We provide a central concept between triple-site ligand binding and the channel gating of human TRPM2. We show consecutive structural rearrangements and channel activation of TRPM2 induced by binding of ADPR in two indispensable locations, and the binding of Ca2+ in the transmembrane domain. The 8-Br-cADPR—an antagonist of cADPR—binds only to the MHR1/2 domain and inhibits TRPM2 by stabilizing the channel in an apo-like conformation. We conclude that MHR1/2 acts as a orthostatic ligand-binding site for TRPM2. The NUDT9-H domain binds to a second ADPR to assist channel activation in vertebrates, but not necessary in invertebrates. Our work provides insights into the gating mechanism of human TRPM2 and its pharmacology.
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Affiliation(s)
- Yihe Huang
- Van Andel Institute, Grand Rapids, United States
| | - Becca Roth
- Van Andel Institute, Grand Rapids, United States
| | - Wei Lü
- Van Andel Institute, Grand Rapids, United States
| | - Juan Du
- Van Andel Institute, Grand Rapids, United States
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13
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Baszczyňski O, Watt JM, Rozewitz MD, Guse AH, Fliegert R, Potter BVL. Synthesis of Terminal Ribose Analogues of Adenosine 5'-Diphosphate Ribose as Probes for the Transient Receptor Potential Cation Channel TRPM2. J Org Chem 2019; 84:6143-6157. [PMID: 30978018 PMCID: PMC6528165 DOI: 10.1021/acs.joc.9b00338] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
![]()
TRPM2
(transient receptor potential cation channel, subfamily M,
member 2) is a nonselective cation channel involved in the response
to oxidative stress and in inflammation. Its role in autoimmune and
neurodegenerative diseases makes it an attractive pharmacological
target. Binding of the nucleotide adenosine 5′-diphosphate
ribose (ADPR) to the cytosolic NUDT9 homology (NUDT9H) domain activates the channel. A detailed understanding of how ADPR
interacts with the TRPM2 ligand binding domain is lacking, hampering
the rational design of modulators, but the terminal ribose of ADPR
is known to be essential for activation. To study its role in more
detail, we designed synthetic routes to novel analogues of ADPR and
2′-deoxy-ADPR that were modified only by removal of a single
hydroxyl group from the terminal ribose. The ADPR analogues were obtained
by coupling nucleoside phosphorimidazolides to deoxysugar phosphates.
The corresponding C2″-based analogues proved to be unstable.
The C1″- and C3″-ADPR analogues were evaluated electrophysiologically
by patch-clamp in TRPM2-expressing HEK293 cells. In addition, a compound
with all hydroxyl groups of the terminal ribose blocked as its 1″-β-O-methyl-2″,3″-O-isopropylidene
derivative was evaluated. Removal of either C1″ or C3″
hydroxyl groups from ADPR resulted in loss of agonist activity. Both
these modifications and blocking all three hydroxyl groups resulted
in TRPM2 antagonists. Our results demonstrate the critical role of
these hydroxyl groups in channel activation.
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Affiliation(s)
- Ondřej Baszczyňski
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology , University of Bath , Bath BA2 7AY , U.K
| | - Joanna M Watt
- Medicinal Chemistry & Drug Discovery, Department of Pharmacology , University of Oxford , Mansfield Road , Oxford OX1 3QT , U.K.,Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology , University of Bath , Bath BA2 7AY , U.K
| | - Monika D Rozewitz
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology , University Medical Center Hamburg-Eppendorf , Martinistrasse 52 , 20246 Hamburg , Germany
| | - Andreas H Guse
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology , University Medical Center Hamburg-Eppendorf , Martinistrasse 52 , 20246 Hamburg , Germany
| | - Ralf Fliegert
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology , University Medical Center Hamburg-Eppendorf , Martinistrasse 52 , 20246 Hamburg , Germany
| | - Barry V L Potter
- Medicinal Chemistry & Drug Discovery, Department of Pharmacology , University of Oxford , Mansfield Road , Oxford OX1 3QT , U.K.,Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology , University of Bath , Bath BA2 7AY , U.K
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