@article{MTMT:34064647, title = {Functional characterization of the transient receptor potential melastatin 2 (TRPM2) cation channel from Nematostella vectensis reconstituted into lipid bilayer}, url = {https://m2.mtmt.hu/api/publication/34064647}, author = {Szöllősi, András and Almássy, János}, doi = {10.1038/s41598-023-38640-6}, journal-iso = {SCI REP}, journal = {SCIENTIFIC REPORTS}, volume = {13}, unique-id = {34064647}, issn = {2045-2322}, abstract = {Transient receptor potential melastatin 2 (TRPM2) cation channel activity is required for insulin secretion, immune cell activation and body heat control. Channel activation upon oxidative stress is involved in the pathology of stroke and neurodegenerative disorders. Cytosolic Ca 2+ , ADP-ribose (ADPR) and phosphatidylinositol-4,5-bisphosphate (PIP 2 ) are the obligate activators of the channel. Several TRPM2 cryo-EM structures have been resolved to date, yet functionality of the purified protein has not been tested. Here we reconstituted overexpressed and purified TRPM2 from Nematostella vectensis (nvTRPM2) into lipid bilayers and found that the protein is fully functional. Consistent with the observations in native membranes, nvTRPM2 in lipid bilayers is co-activated by cytosolic Ca 2+ and either ADPR or ADPR-2′-phosphate (ADPRP). The physiological metabolite ADPRP has a higher apparent affinity than ADPR. In lipid bilayers nvTRPM2 displays a large linear unitary conductance, its open probability (P o ) shows little voltage dependence and is stable over several minutes. P o is high without addition of exogenous PIP 2 , but is largely blunted by treatment with poly- l -Lysine, a polycation that masks PIP 2 headgroups. These results indicate that PIP 2 or some other activating phosphoinositol lipid co-purifies with nvTRPM2, suggesting a high PIP 2 binding affinity of nvTRPM2 under physiological conditions.}, year = {2023}, eissn = {2045-2322}, orcid-numbers = {Szöllősi, András/0000-0002-5570-4609} } @article{MTMT:33262968, title = {Dual amplification strategy turns TRPM2 channels into supersensitive central heat detectors}, url = {https://m2.mtmt.hu/api/publication/33262968}, author = {Bartók, Ádám and Csanády, László}, doi = {10.1073/pnas.2212378119}, journal-iso = {P NATL ACAD SCI USA}, journal = {PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, volume = {119}, unique-id = {33262968}, issn = {0027-8424}, abstract = {The Ca 2+ and ADP ribose (ADPR)-activated cation channel TRPM2 is the closest homolog of the cold sensor TRPM8 but serves as a deep-brain warmth sensor. To unravel the molecular mechanism of heat sensing by the TRPM2 protein, we study here temperature dependence of TRPM2 currents in cell-free membrane patches across ranges of agonist concentrations. We find that channel gating remains strictly agonist-dependent even at 40°C: heating alone or in combination with just Ca 2+ , just ADPR, Ca 2+ + cyclic ADPR, or H 2 O 2 pretreatment only marginally activates TRPM2. For fully liganded TRPM2, pore opening is intrinsically endothermic, due to ~10-fold larger activation enthalpy for opening (~200 kJ/mol) than for closure (~20 kJ/mol). However, the temperature threshold is too high (>40°C) for unliganded but too low (<15°C) for fully liganded channels. Thus, warmth sensitivity around 37°C is restricted to narrow ranges of agonist concentrations. For ADPR, that range matches, but for Ca 2+ , it exceeds bulk cytosolic values. The supraphysiological [Ca 2+ ] needed for TRPM2 warmth sensitivity is provided by Ca 2+ entering through the channel’s pore. That positive feedback provides further strong amplification to the TRPM2 temperature response (Q 10 ~ 1,000), enabling the TRPM2 protein to autonomously respond to tiny temperature fluctuations around 37°C. These functional data together with published structures suggest a molecular mechanism for opposite temperature dependences of two closely related channel proteins.}, year = {2022}, eissn = {1091-6490}, orcid-numbers = {Bartók, Ádám/0000-0002-1232-5246; Csanády, László/0000-0002-6547-5889} } @article{MTMT:32793002, title = {cADPR Does Not Activate TRPM2}, url = {https://m2.mtmt.hu/api/publication/32793002}, author = {Riekehr, W.M. and Sander, S. and Pick, J. and Tidow, H. and Bauche, A. and Guse, A.H. and Fliegert, R.}, doi = {10.3390/ijms23063163}, journal-iso = {INT J MOL SCI}, journal = {INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES}, volume = {23}, unique-id = {32793002}, issn = {1661-6596}, abstract = {cADPR is a second messenger that releases Ca2+ from intracellular stores via the ryanodine receptor. Over more than 15 years, it has been controversially discussed whether cADPR also contributes to the activation of the nucleotide-gated cation channel TRPM2. While some groups have observed activation of TRPM2 by cADPR alone or in synergy with ADPR, sometimes only at 37◦ C, others have argued that this is due to the contamination of cADPR by ADPR. The identification of a novel nucleotide-binding site in the N-terminus of TRPM2 that binds ADPR in a horseshoe-like conformation resembling cADPR as well as the cADPR antagonist 8-Br-cADPR, and another report that demonstrates activation of TRPM2 by binding of cADPR to the NUDT9H domain raised the question again and led us to revisit the topic. Here we show that (i) the N-terminal MHR1/2 domain and the C-terminal NUDT9H domain are required for activation of human TRPM2 by ADPR and 2′-deoxy-ADPR (2dADPR), (ii) that pure cADPR does not activate TRPM2 under a variety of conditions that have previously been shown to result in channel activation, (iii) the cADPR antagonist 8-Br-cADPR also inhibits activation of TRPM2 by ADPR, and (iv) cADPR does not bind to the MHR1/2 domain of TRPM2 while ADPR does. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.}, keywords = {transient receptor potential channel; second messenger; Calcium signalling; Cyclic adenosine 5′-diphosphate ribose}, year = {2022}, eissn = {1422-0067} } @article{MTMT:33063833, title = {The crystal structure of TRPM2 MHR1/2 domain reveals a conserved Zn2+-binding domain essential for structural integrity and channel activity}, url = {https://m2.mtmt.hu/api/publication/33063833}, author = {Sander, S. and Pick, J. and Gattkowski, E. and Fliegert, R. and Tidow, H.}, doi = {10.1002/pro.4320}, journal-iso = {PROTEIN SCI}, journal = {PROTEIN SCIENCE}, volume = {31}, unique-id = {33063833}, issn = {0961-8368}, abstract = {Transient receptor potential melastatin 2 (TRPM2) is a Ca2+-permeable, nonselective cation channel involved in diverse physiological processes such as immune response, apoptosis, and body temperature sensing. TRPM2 is activated by ADP-ribose (ADPR) and 2′-deoxy-ADPR in a Ca2+-dependent manner. While two distinct binding sites exist for ADPR that exert different functions dependent on the species, the involvement of either binding site regarding the superagonistic effect of 2′-deoxy-ADPR is not clear yet. Here, we report the crystal structure of the MHR1/2 domain of TRPM2 from zebrafish (Danio rerio), and show that both ligands bind to this domain and activate the channel. We identified a so far unrecognized Zn2+-binding domain that was not resolved in previous cryo-EM structures and that is conserved in most TRPM channels. In combination with patch clamp experiments we comprehensively characterize the effect of the Zn2+-binding domain on TRPM2 activation. Our results provide insight into a conserved motif essential for structural integrity and channel activity. © 2022 The Authors. Protein Science published by Wiley Periodicals LLC on behalf of The Protein Society.}, keywords = {Animals; metabolism; calcium; calcium; GENETICS; ZEBRAFISH; animal; Chemistry; Electrophysiology; ZINC; ZINC; ZINC; crystal structure; adenosine diphosphate ribose; adenosine diphosphate ribose; zebra fish; transient receptor potential channel M; TRPM Cation Channels; TRPM2; ADPR; 2′-deoxy-ADPR}, year = {2022}, eissn = {1469-896X} } @article{MTMT:32793001, title = {On the Connections between TRPM Channels and SOCE}, url = {https://m2.mtmt.hu/api/publication/32793001}, author = {Sousza, Bomfim G.H. and Niemeyer, B.A. and Lacruz, R.S. and Lis, A.}, doi = {10.3390/cells11071190}, journal-iso = {CELLS-BASEL}, journal = {CELLS}, volume = {11}, unique-id = {32793001}, abstract = {Plasma membrane protein channels provide a passageway for ions to access the intracellular milieu. Rapid entry of calcium ions into cells is controlled mostly by ion channels, while Ca2+-ATPases and Ca2+ exchangers ensure that cytosolic Ca2+ levels ([Ca2+ ]cyt) are maintained at low (~100 nM) concentrations. Some channels, such as the Ca2+-release-activated Ca2+ (CRAC) channels and voltagedependent Ca2+ channels (CACNAs), are highly Ca2+-selective, while others, including the Transient Receptor Potential Melastatin (TRPM) family, have broader selectivity and are mostly permeable to monovalent and divalent cations. Activation of CRAC channels involves the coupling between ORAI1-3 channels with the endoplasmic reticulum (ER) located Ca2+ store sensor, Stromal Interaction Molecules 1-2 (STIM1/2), a pathway also termed store-operated Ca2+ entry (SOCE). The TRPM family is formed by 8 members (TRPM1-8) permeable to Mg2+, Ca2+, Zn2+ and Na+ cations, and is activated by multiple stimuli. Recent studies indicated that SOCE and TRPM structure-function are interlinked in some instances, although the molecular details of this interaction are only emerging. Here we review the role of TRPM and SOCE in Ca2+ handling and highlight the available evidence for this interaction. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.}, keywords = {PHOSPHORYLATION; calcium; calcium; CALCIUM CHANNELS; Neuropathic pain; review; human; Electrophysiology; neutrophil; endoplasmic reticulum; Calcium ion; protein phosphorylation; action potential; Transient Receptor Potential Channels; transient receptor potential channel; Adenosine Triphosphate; Circular Dichroism; cyclic GMP; structure activity relation; calcium channel; Calcium Signaling; calcium transport; G protein coupled receptor; calcium homeostasis; protein kinase C alpha; Ca2+ signaling; channel gating; myosin heavy chain; Smad2 protein; transient receptor potential channel M4; transient receptor potential channel M8; stromal interaction molecule 1; calcium release activated calcium channel 1; transient receptor potential channel M3; AMPK signaling; calcium release activated calcium channel; ORAI1 Protein; lipocortin 1; clusterin; store operated calcium entry; transient receptor potential channel M; transient receptor potential channel M1; transient receptor potential channel M6; transient receptor potential channel M7; SOCE; TRPM Cation Channels; stromal interaction molecule 2; TRPM channels; transient receptor potential channel M5; Orai channels; Calcium Release Activated Calcium Channels}, year = {2022}, eissn = {2073-4409} } @article{MTMT:32008293, title = {Species-specific regulation of trpm2 by pi(4,5)p2 via the membrane interfacial cavity}, url = {https://m2.mtmt.hu/api/publication/32008293}, author = {Barth, D. and Lückhoff, A. and Kühn, F.J.P.}, doi = {10.3390/ijms22094637}, journal-iso = {INT J MOL SCI}, journal = {INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES}, volume = {22}, unique-id = {32008293}, issn = {1661-6596}, abstract = {The human apoptosis channel TRPM2 is stimulated by intracellular ADR-ribose and cal-cium. Recent studies show pronounced species-specific activation mechanisms. Our aim was to an-alyse 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. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.}, keywords = {phospholipid; patch clamp; Phosphoinositides; PIP2; TRPM2}, year = {2021}, eissn = {1422-0067} } @article{MTMT:32040119, title = {Two decades of evolution of our understanding of the transient receptor potential melastatin 2 (Trpm2) cation channel}, url = {https://m2.mtmt.hu/api/publication/32040119}, author = {Szöllősi, András}, doi = {10.3390/life11050397}, journal-iso = {LIFE-BASEL}, journal = {LIFE-BASEL}, volume = {11}, unique-id = {32040119}, 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. © 2021 by the author. Licensee MDPI, Basel, Switzerland.}, keywords = {ION CHANNELS; ADP-ribose; Single particle cryo-EM; TRPM2; Nudix hydrolase}, year = {2021}, eissn = {2075-1729}, orcid-numbers = {Szöllősi, András/0000-0002-5570-4609} } @article{MTMT:31697230, title = {Does Cyclic ADP-Ribose (cADPR) Activate the Non-selective Cation Channel TRPM2?}, url = {https://m2.mtmt.hu/api/publication/31697230}, author = {Fliegert, Ralf and Riekehr, Winnie M. and Guse, Andreas H.}, doi = {10.3389/fimmu.2020.02018}, journal-iso = {FRONT IMMUNOL}, journal = {FRONTIERS IN IMMUNOLOGY}, volume = {11}, unique-id = {31697230}, issn = {1664-3224}, 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 Ca(2+)mobilizing second messenger cyclic ADP ribose (cADPR) might also directly activate Ca(2+)entry via TRPM2. Here we will review the status of this discussion.}, keywords = {calcium; signal transduction; ion channel; TRPM2; cADPR}, year = {2020}, eissn = {1664-3224} } @article{MTMT:31721367, title = {Transient receptor potential channels: current perspectives on evolution, structure, function and nomenclature}, url = {https://m2.mtmt.hu/api/publication/31721367}, author = {Himmel, Nathaniel J. and Cox, Daniel N.}, doi = {10.1098/rspb.2020.1309}, journal-iso = {P ROY SOC B-BIOL SCI}, journal = {PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES}, volume = {287}, unique-id = {31721367}, issn = {0962-8452}, abstract = {The transient receptor potential superfamily of ion channels (TRP channels) is widely recognized for the roles its members play in sensory nervous systems. However, the incredible diversity within the TRP superfamily, and the wide range of sensory capacities found therein, has also allowed TRP channels to function beyond sensing an organism's external environment, and TRP channels have thus become broadly critical to (at least) animal life. TRP channels were originally discovered inDrosophilaand have since been broadly studied in animals; however, thanks to a boom in genomic and transcriptomic data, we now know that TRP channels are present in the genomes of a variety of creatures, including green algae, fungi, choanoflagellates and a number of other eukaryotes. As a result, the organization of the TRP superfamily has changed radically from its original description. Moreover, modern comprehensive phylogenetic analyses have brought to light the vertebrate-centricity of much of the TRP literature; much of the nomenclature has been grounded in vertebrate TRP subfamilies, resulting in a glossing over of TRP channels in other taxa. Here, we provide a comprehensive review of the function, structure and evolutionary history of TRP channels, and put forth a more complete set of non-vertebrate-centric TRP family, subfamily and other subgroup nomenclature.}, keywords = {molecular evolution; transient receptor potential evolution; transient receptor potential phylogeny; ion channel evolution}, year = {2020}, eissn = {1471-2954} } @article{MTMT:31697231, title = {Structure-Function Relationship of TRPM2: Recent Advances, Contradictions, and Open Questions}, url = {https://m2.mtmt.hu/api/publication/31697231}, author = {Kuehn, Frank J. P.}, doi = {10.3390/ijms21186481}, journal-iso = {INT J MOL SCI}, journal = {INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES}, volume = {21}, unique-id = {31697231}, issn = {1661-6596}, 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.}, keywords = {transient receptor potential; cryogenic electron microscopy; adenosine diphospho ribose; NUDT9; ion channel orthologous}, year = {2020}, eissn = {1422-0067} } @article{MTMT:31366156, title = {The N-terminal domain in TRPM2 channel is a conserved nucleotide binding site}, url = {https://m2.mtmt.hu/api/publication/31366156}, author = {Lu, Wei and Du, Juan}, doi = {10.1085/jgp.201912555}, journal-iso = {J GEN PHYSIOL}, journal = {JOURNAL OF GENERAL PHYSIOLOGY}, volume = {152}, unique-id = {31366156}, issn = {0022-1295}, year = {2020}, eissn = {1540-7748} } @article{MTMT:31721987, title = {Medicinal chemistry perspective of TRPM2 channel inhibitors: where we are and where we might be heading?}, url = {https://m2.mtmt.hu/api/publication/31721987}, author = {Zhang, H. and Zhao, S. and Yu, J. and Yang, W. and Liu, Z. and Zhang, L.}, doi = {10.1016/j.drudis.2020.09.039}, journal-iso = {DRUG DISCOV TODAY}, journal = {DRUG DISCOVERY TODAY}, volume = {25}, unique-id = {31721987}, issn = {1359-6446}, abstract = {Transient receptor potential melastatin 2 (TRPM2) is a Ca2+- permeable nonselective cation channel that is involved in diverse biological functions as a cellular sensor for oxidative stress and temperature. It has been considered a promising therapeutic target for the treatment of ischemia/reperfusion (IR) injury, inflammation, cancer, and neurodegenerative diseases. Development of highly potent and selective TRPM2 inhibitors and validation of their use in relevant disease models will advance drug discovery. In this review, we describe the molecular structures and gating mechanism of the TRPM2 channel, and offer a comprehensive review of advances in the discovery of TRPM2 inhibitors. Furthermore, we analyze the properties of reported TRPM2 inhibitors with an emphasis on how specific inhibitors targeting this channel could be better developed. © 2020 Elsevier Ltd}, year = {2020}, eissn = {1878-5832}, pages = {2326-2334} }