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Voltage-gating and cytosolic Ca 2+ activation mechanisms of Arabidopsis two-pore channel AtTPC1. Proc Natl Acad Sci U S A 2021; 118:2113946118. [PMID: 34845029 DOI: 10.1073/pnas.2113946118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2021] [Indexed: 11/18/2022] Open
Abstract
Arabidopsis thaliana two-pore channel AtTPC1 is a voltage-gated, Ca2+-modulated, nonselective cation channel that is localized in the vacuolar membrane and responsible for generating slow vacuolar (SV) current. Under depolarizing membrane potential, cytosolic Ca2+ activates AtTPC1 by binding at the EF-hand domain, whereas luminal Ca2+ inhibits the channel by stabilizing the voltage-sensing domain II (VSDII) in the resting state. Here, we present 2.8 to 3.3 Å cryoelectron microscopy (cryo-EM) structures of AtTPC1 in two conformations, one in closed conformation with unbound EF-hand domain and resting VSDII and the other in a partially open conformation with Ca2+-bound EF-hand domain and activated VSDII. Structural comparison between the two different conformations allows us to elucidate the structural mechanisms of voltage gating, cytosolic Ca2+ activation, and their coupling in AtTPC1. This study also provides structural insight into the general voltage-gating mechanism among voltage-gated ion channels.
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52
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Davis LC, Morgan AJ, Galione A. Acidic Ca 2+ stores and immune-cell function. Cell Calcium 2021; 101:102516. [PMID: 34922066 DOI: 10.1016/j.ceca.2021.102516] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/03/2021] [Accepted: 12/04/2021] [Indexed: 12/11/2022]
Abstract
Acidic organelles act as intracellular Ca2+ stores; they actively sequester Ca2+ in their lumina and release it to the cytosol upon activation of endo-lysosomal Ca2+ channels. Recent data suggest important roles of endo-lysosomal Ca2+ channels, the Two-Pore Channels (TPCs) and the TRPML channels (mucolipins), in different aspects of immune-cell function, particularly impacting membrane trafficking, vesicle fusion/fission and secretion. Remarkably, different channels on the same acidic vesicles can couple to different downstream physiology. Endo-lysosomal Ca2+ stores can act under different modalities, be they acting alone (via local Ca2+ nanodomains around TPCs/TRPMLs) or in conjunction with the ER Ca2+ store (to either promote or suppress global ER Ca2+ release). These different modalities impinge upon functions as broad as phagocytosis, cell-killing, anaphylaxis, immune memory, thrombostasis, and chemotaxis.
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Affiliation(s)
- Lianne C Davis
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
| | - Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
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53
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Hijikata A, Shionyu-Mitsuyama C, Nakae S, Shionyu M, Ota M, Kanaya S, Hirokawa T, Nakajima S, Watashi K, Shirai T. Evaluating cepharanthine analogues as natural drugs against SARS-CoV-2. FEBS Open Bio 2021; 12:285-294. [PMID: 34850606 PMCID: PMC8727928 DOI: 10.1002/2211-5463.13337] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/01/2021] [Accepted: 11/27/2021] [Indexed: 12/12/2022] Open
Abstract
Cepharanthine (CEP) is a natural biscoclaurine alkaloid of plant origin and was recently demonstrated to have anti‐severe acute respiratory syndrome coronavirus 2 (anti‐SARS‐CoV‐2) activity. In this study, we evaluated whether natural analogues of CEP may act as potential anti‐coronavirus disease 2019 drugs. A total of 24 compounds resembling CEP were extracted from the KNApSAcK database, and their binding affinities to target proteins, including the spike protein and main protease of SARS‐CoV‐2, NPC1 and TPC2 in humans, were predicted via molecular docking simulations. Selected analogues were further evaluated by a cell‐based SARS‐CoV‐2 infection assay. In addition, the efficacies of CEP and its analogue tetrandrine were assessed. A comparison of the docking conformations of these compounds suggested that the diphenyl ester moiety of the molecules was a putative pharmacophore of the CEP analogues.
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Affiliation(s)
- Atsushi Hijikata
- Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Japan
| | | | - Setsu Nakae
- Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Japan
| | - Masafumi Shionyu
- Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Japan
| | - Motonori Ota
- Department of Complex Systems Science, Graduate School of Informatics, Nagoya University, Japan
| | - Shigehiko Kanaya
- Computational Biology Laboratory Division of Information Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Ikoma, Japan
| | - Takatsugu Hirokawa
- Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Japan.,Transborder Medical Research Center, University of Tsukuba, Japan.,Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, Tokyo, Japan
| | - Shogo Nakajima
- Department of Virology II, National Institute of Infectious Diseases, Shinjuku-ku, Japan
| | - Koichi Watashi
- Department of Virology II, National Institute of Infectious Diseases, Shinjuku-ku, Japan.,Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Shinjuku-ku, Japan.,Department of Applied Biological Sciences, Tokyo University of Science, Noda, Japan
| | - Tsuyoshi Shirai
- Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Japan
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54
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Hirazawa K, Tateyama M, Kubo Y, Shimomura T. Phosphoinositide regulates dynamic movement of the S4 voltage sensor in the second repeat in two-pore channel 3. J Biol Chem 2021; 297:101425. [PMID: 34800436 PMCID: PMC8665364 DOI: 10.1016/j.jbc.2021.101425] [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: 06/23/2021] [Revised: 11/11/2021] [Accepted: 11/15/2021] [Indexed: 11/24/2022] Open
Abstract
The two-pore channels (TPCs) are voltage-gated cation channels consisting of single polypeptides with two repeats of a canonical 6-transmembrane unit. TPCs are known to be regulated by various physiological signals such as membrane voltage and phosphoinositide (PI). The fourth helix in the second repeat (second S4) plays a major role in detecting membrane voltage, whereas the first repeat contains a PI binding site. Therefore, each of these stimuli is detected by a unique repeat to regulate the gating of the TPC central pore. How these various stimuli regulate the dynamic structural rearrangement of the TPC molecule remain unknown. Here, we found that PI binding to the first repeat in TPC3 regulates the movement of the distally located second S4 helix, showing that the PI-binding signal is not confined to the pore gate but also transmitted to the voltage sensor. Using voltage clamp fluorometry, measurement of gating charges, and Cys-accessibility analysis, we observed that PI binding significantly potentiates the voltage dependence of the movement of the second S4 helix. Notably, voltage clamp fluorometry analysis revealed that the voltage-dependent movement of the second S4 helix occurred in two phases, of which the second phase corresponds to the transfer of the gating charges. This movement was observed in the voltage range where gate-opening occurs and was potentiated by PI. In conclusion, this regulation of the second S4 helix by PI indicates a tight inter-repeat coupling within TPC3, a feature which might be conserved among TPC family members to integrate various physiological signals.
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Affiliation(s)
- Kiichi Hirazawa
- Division of Biophysics and Neurobiology, National Institute for Physiological Sciences, Okazaki, Japan; Department of Physiological Sciences, The Graduate University for Advanced Studies, Hayama, Japan
| | - Michihiro Tateyama
- Division of Biophysics and Neurobiology, National Institute for Physiological Sciences, Okazaki, Japan; Department of Physiological Sciences, The Graduate University for Advanced Studies, Hayama, Japan
| | - Yoshihiro Kubo
- Division of Biophysics and Neurobiology, National Institute for Physiological Sciences, Okazaki, Japan; Department of Physiological Sciences, The Graduate University for Advanced Studies, Hayama, Japan
| | - Takushi Shimomura
- Division of Biophysics and Neurobiology, National Institute for Physiological Sciences, Okazaki, Japan; Department of Physiological Sciences, The Graduate University for Advanced Studies, Hayama, Japan.
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55
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Dendrite tapering actuates a self-organizing signaling circuit for stochastic filopodia initiation in neurons. Proc Natl Acad Sci U S A 2021; 118:2106921118. [PMID: 34686599 DOI: 10.1073/pnas.2106921118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2021] [Indexed: 01/09/2023] Open
Abstract
How signaling units spontaneously arise from a noisy cellular background is not well understood. Here, we show that stochastic membrane deformations can nucleate exploratory dendritic filopodia, dynamic actin-rich structures used by neurons to sample its surroundings for compatible transcellular contacts. A theoretical analysis demonstrates that corecruitment of positive and negative curvature-sensitive proteins to deformed membranes minimizes the free energy of the system, allowing the formation of long-lived curved membrane sections from stochastic membrane fluctuations. Quantitative experiments show that once recruited, curvature-sensitive proteins form a signaling circuit composed of interlinked positive and negative actin-regulatory feedback loops. As the positive but not the negative feedback loop can sense the dendrite diameter, this self-organizing circuit determines filopodia initiation frequency along tapering dendrites. Together, our findings identify a receptor-independent signaling circuit that employs random membrane deformations to simultaneously elicit and limit formation of exploratory filopodia to distal dendritic sites of developing neurons.
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56
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Milenkovic S, Bodrenko IV, Carpaneto A, Ceccarelli M. The key role of the central cavity in sodium transport through ligand-gated two-pore channels. Phys Chem Chem Phys 2021; 23:18461-18474. [PMID: 34612386 DOI: 10.1039/d1cp02947a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Subcellular and organellar mechanisms have manifested a prominent importance for a broad variety of processes that maintain cellular life at its most basic level. Mammalian two-pore channels (TPCs) appear to be cornerstones of these processes in endo-lysosomes by controlling delicate ion-concentrations in their interiors. With evolutionary remarkable architecture and one-of-a-kind selectivity filter, TPCs are an extremely attractive topic per se. In the light of the current COVID-19 pandemic, hTPC2 emerges to be more than attractive. As a key regulator of the endocytosis pathway, it is potentially essential for diverse viral infections in humans, as demonstrated. Here, by means of multiscale molecular simulations, we propose a model of sodium transport from the lumen to the cytosol where the central cavity works as a reservoir. Since the inhibition of hTPC2 is proven to stop SARS-CoV2 in vitro, shedding light on the hTPC2 function and mechanism is the first step towards the selection of potential inhibiting candidates.
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Affiliation(s)
- Stefan Milenkovic
- Department of Physics, University of Cagliari, 09042 Monserrato, Italy.
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57
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Lv L, Zhang L. Host proviral and antiviral factors for SARS-CoV-2. Virus Genes 2021; 57:475-488. [PMID: 34510331 PMCID: PMC8435179 DOI: 10.1007/s11262-021-01869-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 08/28/2021] [Indexed: 12/12/2022]
Abstract
Throughout the viral life cycle, interplays between cellular host factors and virus determine the infectious capacity of the virus. The pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a great threat to human life and health. Extensive studies identified a number of host proviral and antiviral factors for SARS-CoV-2. In this review, we summarize the current understanding of the interplay between SARS-CoV-2 and cellular factors during virus entry and replication. Our review will highlight the future direction of study on the infection and pathogenesis of SARS-CoV-2, as well as novel therapeutic strategies and effective antiviral targets for COVID-19.
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Affiliation(s)
- Lu Lv
- Department of Pathogen Biology, School of Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117, Shandong, China.,Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117, Shandong, China
| | - Leiliang Zhang
- Department of Pathogen Biology, School of Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117, Shandong, China. .,Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117, Shandong, China.
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58
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Ayele AG, Enyew EF, Kifle ZD. Roles of existing drug and drug targets for COVID-19 management. Metabol Open 2021; 11:100103. [PMID: 34222852 PMCID: PMC8239316 DOI: 10.1016/j.metop.2021.100103] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 06/27/2021] [Indexed: 02/07/2023] Open
Abstract
In December 2019, a highly transmissible, pneumonia epidemic caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), erupted in China and other countries, resulting in devastation and health crisis worldwide currently. The search and using existing drugs support to curb the current highly contagious viral infection is spirally increasing since the pandemic began. This is based on these drugs had against other related RNA-viruses such as MERS-Cov, and SARS-Cov. Moreover, researchers are scrambling to identify novel drug targets and discover novel therapeutic options to vanquish the current pandemic. Since there is no definitive treatment to control Covid-19 vaccines are remain to be a lifeline. Currently, many vaccine candidates are being developed with most of them are reported to have positive results. Therapeutic targets such as helicases, transmembrane serine protease 2, cathepsin L, cyclin G-associated kinase, adaptor-associated kinase 1, two-pore channel, viral virulence factors, 3-chymotrypsin-like protease, suppression of excessive inflammatory response, inhibition of viral membrane, nucleocapsid, envelope, and accessory proteins, and inhibition of endocytosis were identified as a potential target against COVID-19 infection. This review also summarizes plant-based medicines for the treatment of COVID-19 such as saposhnikoviae divaricata, lonicerae japonicae flos, scutellaria baicalensis, lonicera japonicae, and some others. Thus, this review aimed to focus on the most promising therapeutic targets being repurposed against COVID-19 and viral elements that are used in COVID-19 vaccine candidates.
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Key Words
- 3CLpro, 3-chymotrypsin-like protease
- AAK1, adaptor-associated kinase 1
- ACE-2, Angiotensin-Converting Enzyme-2
- CEF, Cepharanthine
- COVID-19
- COVID-19, coronavirus disease-2019
- Existing drug
- GAK, cyclin G-associated kinase
- MERS-CoV, Middle East respiratory syndrome coronavirus
- Management
- Nsp, non-structure protein
- ORF, open reading frame
- PLpro, papain-like protease
- RdRp, RNA-dependence RNA-polymerase
- SARS-COV-2, severe acute respiratory syndrome coronavirus-2
- TMPRSS2, transmembrane Serine Protease 2
- TPC2, two-pore channel 2
- Therapeutic target
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Affiliation(s)
- Akeberegn Gorems Ayele
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Science, Addis Ababa University, Addis Ababa, Ethiopia
| | - Engidaw Fentahun Enyew
- Department of Human Anatomy, School of Medicine, College of Medicine and Health Sciences, Gondar, Ethiopia
| | - Zemene Demelash Kifle
- Department of Pharmacology, School of Pharmacy, College of Medicine and Health Science, University of Gondar, Gondar, Ethiopia
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59
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Jin X, Zhang Y, Alharbi A, Hanbashi A, Alhoshani A, Parrington J. Targeting Two-Pore Channels: Current Progress and Future Challenges. Trends Pharmacol Sci 2021; 41:582-594. [PMID: 32679067 PMCID: PMC7365084 DOI: 10.1016/j.tips.2020.06.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/04/2020] [Accepted: 06/04/2020] [Indexed: 12/19/2022]
Abstract
Two-pore channels (TPCs) are cation-permeable channels located on endolysosomal membranes and important mediators of intracellular Ca2+ signalling. TPCs are involved in various pathophysiological processes, including cell growth and development, metabolism, and cancer progression. Most studies of TPCs have used TPC–/– cell or whole-animal models, or Ned-19, an indirect inhibitor. The TPC activation mechanism remains controversial, which has made it difficult to develop selective modulators. Recent studies of TPC structure and their interactomes are aiding the development of direct pharmacological modulators. This process is still in its infancy, but will facilitate future research and TPC targeting for therapeutical purposes. Here, we review the progress of current research into TPCs, including recent insights into their structures, functional roles, mechanisms of activation, and pharmacological modulators. Two-pore channel (TPC)-mediated endolysosomal Ca2+ signalling regulates a variety of processes, including cell proliferation, differentiation, metabolism, viral infection, and cardiac function. Despite the well-established model that TPCs are Ca2+-selective channels indirectly activated by nicotinic acid adenine dinucleotide phosphate (NAADP), it has also been proposed that TPCs as Na+ channels are activated directly by phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2]. 3D structures of mouse TPC1 and human TPC2 were recently determined, which made it possible for structure-based virtual screening methods to identify pharmacological modulators of TPC. Recent identification by high-throughput screens of pharmacological modulators that target TPCs will help reveal the molecular mechanisms underlying the role of endolysosomal Ca2+ signalling in different pathophysiological processes, and to develop new therapeutics.
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Affiliation(s)
- Xuhui Jin
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Yuxuan Zhang
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Abeer Alharbi
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Ali Hanbashi
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Ali Alhoshani
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, PO Box 2457, Riyadh 11454, Kingdom of Saudi Arabia
| | - John Parrington
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
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60
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Abstract
Calcium (Ca2+) is a unique mineral that serves as both a nutrient and a signal in all eukaryotes. To maintain Ca2+ homeostasis for both nutrition and signaling purposes, the toolkit for Ca2+ transport has expanded across kingdoms of eukaryotes to encode specific Ca2+ signals referred to as Ca2+ signatures. In parallel, a large array of Ca2+-binding proteins has evolved as specific sensors to decode Ca2+ signatures. By comparing these coding and decoding mechanisms in fungi, animals, and plants, both unified and divergent themes have emerged, and the underlying complexity will challenge researchers for years to come. Considering the scale and breadth of the subject, instead of a literature survey, in this review we focus on a conceptual framework that aims to introduce to readers to the principles and mechanisms of Ca2+ signaling. We finish with several examples of Ca2+-signaling pathways, including polarized cell growth, immunity and symbiosis, and systemic signaling, to piece together specific coding and decoding mechanisms in plants versus animals. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Sheng Luan
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Chao Wang
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
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61
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Koirala M, Shashikala HBM, Jeffries J, Wu B, Loftus SK, Zippin JH, Alexov E. Computational Investigation of the pH Dependence of Stability of Melanosome Proteins: Implication for Melanosome formation and Disease. Int J Mol Sci 2021; 22:ijms22158273. [PMID: 34361043 PMCID: PMC8347052 DOI: 10.3390/ijms22158273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/27/2021] [Accepted: 07/29/2021] [Indexed: 11/16/2022] Open
Abstract
Intravesicular pH plays a crucial role in melanosome maturation and function. Melanosomal pH changes during maturation from very acidic in the early stages to neutral in late stages. Neutral pH is critical for providing optimal conditions for the rate-limiting, pH-sensitive melanin-synthesizing enzyme tyrosinase (TYR). This dramatic change in pH is thought to result from the activity of several proteins that control melanosomal pH. Here, we computationally investigated the pH-dependent stability of several melanosomal membrane proteins and compared them to the pH dependence of the stability of TYR. We confirmed that the pH optimum of TYR is neutral, and we also found that proteins that are negative regulators of melanosomal pH are predicted to function optimally at neutral pH. In contrast, positive pH regulators were predicted to have an acidic pH optimum. We propose a competitive mechanism among positive and negative regulators that results in pH equilibrium. Our findings are consistent with previous work that demonstrated a correlation between the pH optima of stability and activity, and they are consistent with the expected activity of positive and negative regulators of melanosomal pH. Furthermore, our data suggest that disease-causing variants impact the pH dependence of melanosomal proteins; this is particularly prominent for the OCA2 protein. In conclusion, melanosomal pH appears to affect the activity of multiple melanosomal proteins.
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Affiliation(s)
- Mahesh Koirala
- Department of Physics, Clemson University, Clemson, SC 29634, USA; (M.K.); (H.B.M.S.); (J.J.); (B.W.)
| | - H. B. Mihiri Shashikala
- Department of Physics, Clemson University, Clemson, SC 29634, USA; (M.K.); (H.B.M.S.); (J.J.); (B.W.)
| | - Jacob Jeffries
- Department of Physics, Clemson University, Clemson, SC 29634, USA; (M.K.); (H.B.M.S.); (J.J.); (B.W.)
| | - Bohua Wu
- Department of Physics, Clemson University, Clemson, SC 29634, USA; (M.K.); (H.B.M.S.); (J.J.); (B.W.)
| | - Stacie K. Loftus
- Genetic Disease Research Branch, National Human Genome Research Branch, National Institutes of Health, Bethesda, MD 22066, USA;
| | - Jonathan H. Zippin
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA;
| | - Emil Alexov
- Department of Physics, Clemson University, Clemson, SC 29634, USA; (M.K.); (H.B.M.S.); (J.J.); (B.W.)
- Correspondence:
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62
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Two-Pore Channels Regulate Expression of Various Receptors and Their Pathway-Related Proteins in Multiple Ways. Cells 2021; 10:cells10071807. [PMID: 34359976 PMCID: PMC8307395 DOI: 10.3390/cells10071807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 11/17/2022] Open
Abstract
Two-pore channels (TPCs) constitute a small family of ion channels within membranes of intracellular acidic compartments, such as endosomes and lysosomes. They were shown to provide transient and locally restricted Ca2+-currents, likely responsible for fusion and/or fission events of endolysosomal membranes and thereby for intracellular vesicle trafficking. Genetic deletion of TPCs not only affects endocytosis, recycling, and degradation of various surface receptors but also uptake and impact of bacterial protein toxins and entry and intracellular processing of some types of viruses. This review points to important examples of these trafficking defects on one part but mainly focuses on the resulting impact of the TPC inactivation on receptor expression and receptor signaling. Thus, a detailed RNA sequencing analysis using TPC1-deficient fibroblasts uncovered a multitude of changes in the expression levels of surface receptors and their pathway-related signaling proteins. We refer to several classes of receptors such as EGF, TGF, and insulin as well as proteins involved in endocytosis.
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63
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Ritter M, Bresgen N, Kerschbaum HH. From Pinocytosis to Methuosis-Fluid Consumption as a Risk Factor for Cell Death. Front Cell Dev Biol 2021; 9:651982. [PMID: 34249909 PMCID: PMC8261248 DOI: 10.3389/fcell.2021.651982] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/29/2021] [Indexed: 12/11/2022] Open
Abstract
The volumes of a cell [cell volume (CV)] and its organelles are adjusted by osmoregulatory processes. During pinocytosis, extracellular fluid volume equivalent to its CV is incorporated within an hour and membrane area equivalent to the cell's surface within 30 min. Since neither fluid uptake nor membrane consumption leads to swelling or shrinkage, cells must be equipped with potent volume regulatory mechanisms. Normally, cells respond to outwardly or inwardly directed osmotic gradients by a volume decrease and increase, respectively, i.e., they shrink or swell but then try to recover their CV. However, when a cell death (CD) pathway is triggered, CV persistently decreases in isotonic conditions in apoptosis and it increases in necrosis. One type of CD associated with cell swelling is due to a dysfunctional pinocytosis. Methuosis, a non-apoptotic CD phenotype, occurs when cells accumulate too much fluid by macropinocytosis. In contrast to functional pinocytosis, in methuosis, macropinosomes neither recycle nor fuse with lysosomes but with each other to form giant vacuoles, which finally cause rupture of the plasma membrane (PM). Understanding methuosis longs for the understanding of the ionic mechanisms of cell volume regulation (CVR) and vesicular volume regulation (VVR). In nascent macropinosomes, ion channels and transporters are derived from the PM. Along trafficking from the PM to the perinuclear area, the equipment of channels and transporters of the vesicle membrane changes by retrieval, addition, and recycling from and back to the PM, causing profound changes in vesicular ion concentrations, acidification, and-most importantly-shrinkage of the macropinosome, which is indispensable for its proper targeting and cargo processing. In this review, we discuss ion and water transport mechanisms with respect to CVR and VVR and with special emphasis on pinocytosis and methuosis. We describe various aspects of the complex mutual interplay between extracellular and intracellular ions and ion gradients, the PM and vesicular membrane, phosphoinositides, monomeric G proteins and their targets, as well as the submembranous cytoskeleton. Our aim is to highlight important cellular mechanisms, components, and processes that may lead to methuotic CD upon their derangement.
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Affiliation(s)
- Markus Ritter
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria
- Institute for Physiology and Pathophysiology, Paracelsus Medical University, Nuremberg, Germany
- Gastein Research Institute, Paracelsus Medical University, Salzburg, Austria
- Ludwig Boltzmann Institute for Arthritis und Rehabilitation, Salzburg, Austria
- Kathmandu University School of Medical Sciences, Dhulikhel, Nepal
| | - Nikolaus Bresgen
- Department of Biosciences, University of Salzburg, Salzburg, Austria
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64
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Overduin M, Trieber C, Prosser RS, Picard LP, Sheff JG. Structures and Dynamics of Native-State Transmembrane Protein Targets and Bound Lipids. MEMBRANES 2021; 11:451. [PMID: 34204456 PMCID: PMC8235241 DOI: 10.3390/membranes11060451] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/08/2021] [Accepted: 06/15/2021] [Indexed: 02/06/2023]
Abstract
Membrane proteins work within asymmetric bilayers of lipid molecules that are critical for their biological structures, dynamics and interactions. These properties are lost when detergents dislodge lipids, ligands and subunits, but are maintained in native nanodiscs formed using styrene maleic acid (SMA) and diisobutylene maleic acid (DIBMA) copolymers. These amphipathic polymers allow extraction of multicomponent complexes of post-translationally modified membrane-bound proteins directly from organ homogenates or membranes from diverse types of cells and organelles. Here, we review the structures and mechanisms of transmembrane targets and their interactions with lipids including phosphoinositides (PIs), as resolved using nanodisc systems and methods including cryo-electron microscopy (cryo-EM) and X-ray diffraction (XRD). We focus on therapeutic targets including several G protein-coupled receptors (GPCRs), as well as ion channels and transporters that are driving the development of next-generation native nanodiscs. The design of new synthetic polymers and complementary biophysical tools bodes well for the future of drug discovery and structural biology of native membrane:protein assemblies (memteins).
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Affiliation(s)
- Michael Overduin
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada;
| | - Catharine Trieber
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada;
| | - R. Scott Prosser
- Department of Chemistry, University of Toronto, UTM, Mississauga, ON L5L 1C6, Canada; (R.S.P.); (L.-P.P.)
| | - Louis-Philippe Picard
- Department of Chemistry, University of Toronto, UTM, Mississauga, ON L5L 1C6, Canada; (R.S.P.); (L.-P.P.)
| | - Joey G. Sheff
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, ON K1A 0R6, Canada;
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Kawanabe A, Mizutani N, Polat OK, Yonezawa T, Kawai T, Mori MX, Okamura Y. Engineering an enhanced voltage-sensing phosphatase. J Gen Physiol 2021; 152:133870. [PMID: 32167537 PMCID: PMC7201886 DOI: 10.1085/jgp.201912491] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 12/05/2019] [Accepted: 02/16/2020] [Indexed: 01/11/2023] Open
Abstract
Voltage-sensing phosphatases (VSP) consist of a membrane-spanning voltage sensor domain and a cytoplasmic region that has enzymatic activity toward phosphoinositides (PIs). VSP enzyme activity is regulated by membrane potential, and its activation leads to rapid and reversible alteration of cellular PIP levels. These properties enable VSPs to be used as a tool for studying the effects of phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) binding to ion channels and transporters. For example, by applying simple changes in the membrane potential, Danio rerio VSP (Dr-VSP) has been used effectively to manipulate PI(4,5)P2 in mammalian cells with few, if any, side effects. In the present study, we report an enhanced version of Dr-VSP as an improved molecular tool for depleting PI(4,5)P2 from cultured mammalian cells. We modified Dr-VSP in two ways. Its voltage-dependent phosphatase activity was enhanced by introducing an aromatic residue at the position of Leu-223 within a membrane-interacting region of the phosphatase domain called the hydrophobic spine. In addition, selective plasma membrane targeting of Dr-VSP was facilitated by fusion with the N-terminal region of Ciona intestinalis VSP. This modified Dr-VSP (CiDr-VSPmChe L223F, or what we call eVSP) induced more drastic voltage-evoked changes in PI(4,5)P2 levels, using the activities of Kir2.1, KCNQ2/3, and TRPC6 channels as functional readouts. eVSP is thus an improved molecular tool for evaluating the PI(4,5)P2 sensitivity of ion channels in living cells.
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Affiliation(s)
- Akira Kawanabe
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Natsuki Mizutani
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Onur K Polat
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Tomoko Yonezawa
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Takafumi Kawai
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Masayuki X Mori
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Yasushi Okamura
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.,Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
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D’Amore A, Gradogna A, Palombi F, Minicozzi V, Ceccarelli M, Carpaneto A, Filippini A. The Discovery of Naringenin as Endolysosomal Two-Pore Channel Inhibitor and Its Emerging Role in SARS-CoV-2 Infection. Cells 2021; 10:1130. [PMID: 34067054 PMCID: PMC8150892 DOI: 10.3390/cells10051130] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/01/2021] [Accepted: 05/04/2021] [Indexed: 12/23/2022] Open
Abstract
The flavonoid naringenin (Nar), present in citrus fruits and tomatoes, has been identified as a blocker of an emerging class of human intracellular channels, namely the two-pore channel (TPC) family, whose role has been established in several diseases. Indeed, Nar was shown to be effective against neoangiogenesis, a process essential for solid tumor progression, by specifically impairing TPC activity. The goal of the present review is to illustrate the rationale that links TPC channels to the mechanism of coronavirus infection, and how their inhibition by Nar could be an efficient pharmacological strategy to fight the current pandemic plague COVID-19.
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Affiliation(s)
- Antonella D’Amore
- Unit of Histology and Medical Embryology, Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Sapienza University of Rome, 16 Via A. Scarpa, 00161 Rome, Italy; (A.D.); (F.P.)
| | - Antonella Gradogna
- Institute of Biophysics, National Research Council, Via De Marini 6, 16149 Genova, Italy
| | - Fioretta Palombi
- Unit of Histology and Medical Embryology, Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Sapienza University of Rome, 16 Via A. Scarpa, 00161 Rome, Italy; (A.D.); (F.P.)
| | - Velia Minicozzi
- INFN and Department of Physics, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma, Italy;
| | - Matteo Ceccarelli
- Department of Physics, University of Cagliari, 09042 Monserrato, Italy;
- IOM-CNR Unità di Cagliari, Cittadella Universitaria, 09042 Monserrato, Italy
| | - Armando Carpaneto
- Institute of Biophysics, National Research Council, Via De Marini 6, 16149 Genova, Italy
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, Viale Benedetto XV 5, 16132 Genova, Italy
| | - Antonio Filippini
- Unit of Histology and Medical Embryology, Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Sapienza University of Rome, 16 Via A. Scarpa, 00161 Rome, Italy; (A.D.); (F.P.)
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Negri S, Faris P, Moccia F. Endolysosomal Ca 2+ signaling in cardiovascular health and disease. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 363:203-269. [PMID: 34392930 DOI: 10.1016/bs.ircmb.2021.03.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
An increase in intracellular Ca2+ concentration ([Ca2+]i) regulates a plethora of functions in the cardiovascular (CV) system, including contraction in cardiomyocytes and vascular smooth muscle cells (VSMCs), and angiogenesis in vascular endothelial cells and endothelial colony forming cells. The sarco/endoplasmic reticulum (SR/ER) represents the largest endogenous Ca2+ store, which releases Ca2+ through ryanodine receptors (RyRs) and/or inositol-1,4,5-trisphosphate receptors (InsP3Rs) upon extracellular stimulation. The acidic vesicles of the endolysosomal (EL) compartment represent an additional endogenous Ca2+ store, which is targeted by several second messengers, including nicotinic acid adenine dinucleotide phosphate (NAADP) and phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2], and may release intraluminal Ca2+ through multiple Ca2+ permeable channels, including two-pore channels 1 and 2 (TPC1-2) and Transient Receptor Potential Mucolipin 1 (TRPML1). Herein, we discuss the emerging, pathophysiological role of EL Ca2+ signaling in the CV system. We describe the role of cardiac TPCs in β-adrenoceptor stimulation, arrhythmia, hypertrophy, and ischemia-reperfusion injury. We then illustrate the role of EL Ca2+ signaling in VSMCs, where TPCs promote vasoconstriction and contribute to pulmonary artery hypertension and atherosclerosis, whereas TRPML1 sustains vasodilation and is also involved in atherosclerosis. Subsequently, we describe the mechanisms whereby endothelial TPCs promote vasodilation, contribute to neurovascular coupling in the brain and stimulate angiogenesis and vasculogenesis. Finally, we discuss about the possibility to target TPCs, which are likely to mediate CV cell infection by the Severe Acute Respiratory Disease-Coronavirus-2, with Food and Drug Administration-approved drugs to alleviate the detrimental effects of Coronavirus Disease-19 on the CV system.
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Affiliation(s)
- Sharon Negri
- Laboratory of Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy
| | - Pawan Faris
- Laboratory of Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy
| | - Francesco Moccia
- Laboratory of Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy.
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Morgan AJ, Davis LC, Galione A. Choreographing endo-lysosomal Ca 2+ throughout the life of a phagosome. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119040. [PMID: 33872669 DOI: 10.1016/j.bbamcr.2021.119040] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/05/2021] [Accepted: 04/07/2021] [Indexed: 12/20/2022]
Abstract
The emergence of endo-lysosomes as ubiquitous Ca2+ stores with their unique cohort of channels has resulted in their being implicated in a growing number of processes in an ever-increasing number of cell types. The architectural and regulatory constraints of these acidic Ca2+ stores distinguishes them from other larger Ca2+ sources such as the ER and influx across the plasma membrane. In view of recent advances in the understanding of the modes of operation, we discuss phagocytosis as a template for how endo-lysosomal Ca2+ signals (generated via TPC and TRPML channels) can be integrated in multiple sophisticated ways into biological processes. Phagocytosis illustrates how different endo-lysosomal Ca2+ signals drive different phases of a process, and how these can be altered by disease or infection.
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Affiliation(s)
- Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Park, Oxford OX1 3QT, UK.
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Mansfield Park, Oxford OX1 3QT, UK
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Mansfield Park, Oxford OX1 3QT, UK.
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Abstract
The COVID-19, an acute respiratory syndrome caused by SARS-CoV2 is a major catastrophic event of the twenty first century. Relentless efforts for the development of effective pharmaco-therapeutics are in progress but the respite is the development of effective vaccines. However, monotherapy might not always exhibit complete efficacy and may culminate in the rapid evolution of drug-resistant viral strains. Hence, simultaneous modulation of multiple druggable targets not only enhances therapeutic efficacy but also quell the prospects of mutant viruses. Currently, milk peptides have bloomed beyond just being a quintessential part of nutrition to prominent therapeutic implications in human health and diseases. Hence, we have focused on colostrum/milk peptides as they have already been acknowledged for their high potency, target specificity with significantly low or no side effects and bio-toleration. The results presented provide a conceptual strategy for the rational designing of prospective multitargeted peptide inhibitors for SARS-CoV2.
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70
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Wakamatsu K, Zippin JH, Ito S. Chemical and biochemical control of skin pigmentation with special emphasis on mixed melanogenesis. Pigment Cell Melanoma Res 2021; 34:730-747. [PMID: 33751833 DOI: 10.1111/pcmr.12970] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 02/24/2021] [Accepted: 03/07/2021] [Indexed: 02/06/2023]
Abstract
Melanins are widely distributed in animals and plants; in vertebrates, most melanins are present on the body surface. The diversity of pigmentation in vertebrates is mainly attributed to the quantity and ratio of eumelanin and pheomelanin synthesis. Most natural melanin pigments in animals consist of both eumelanin and pheomelanin in varying ratios, and thus, their combined synthesis is called "mixed melanogenesis." Gene expression is an established mechanism for controlling melanin synthesis; however, there are multiple factors that affect melanin synthesis besides gene expression. Due to the differential sensitivity of the eumelanin and pheomelanin synthetic pathways to pH, melanosomal pH likely plays a major role in mixed melanogenesis. Here, we focused on various factors affecting mixed melanogenesis including (1) chemical regulation of melanin synthesis, (2) melanosomal pH regulation during normal melanogenesis and effect on mixed melanogenesis, and (3) mechanisms of melanosomal pH control (proton pumps, channels, transporters, and signaling pathways).
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Affiliation(s)
- Kazumasa Wakamatsu
- Institute for Melanin Chemistry, Fujita Health University, Toyoake, Japan
| | - Jonathan H Zippin
- Department of Dermatology, Joan and Sanford I. Weill Medical College of Cornell University, New York, NY, USA
| | - Shosuke Ito
- Institute for Melanin Chemistry, Fujita Health University, Toyoake, Japan
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Waman VP, Sen N, Varadi M, Daina A, Wodak SJ, Zoete V, Velankar S, Orengo C. The impact of structural bioinformatics tools and resources on SARS-CoV-2 research and therapeutic strategies. Brief Bioinform 2021; 22:742-768. [PMID: 33348379 PMCID: PMC7799268 DOI: 10.1093/bib/bbaa362] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/06/2020] [Accepted: 11/09/2020] [Indexed: 01/18/2023] Open
Abstract
SARS-CoV-2 is the causative agent of COVID-19, the ongoing global pandemic. It has posed a worldwide challenge to human health as no effective treatment is currently available to combat the disease. Its severity has led to unprecedented collaborative initiatives for therapeutic solutions against COVID-19. Studies resorting to structure-based drug design for COVID-19 are plethoric and show good promise. Structural biology provides key insights into 3D structures, critical residues/mutations in SARS-CoV-2 proteins, implicated in infectivity, molecular recognition and susceptibility to a broad range of host species. The detailed understanding of viral proteins and their complexes with host receptors and candidate epitope/lead compounds is the key to developing a structure-guided therapeutic design. Since the discovery of SARS-CoV-2, several structures of its proteins have been determined experimentally at an unprecedented speed and deposited in the Protein Data Bank. Further, specialized structural bioinformatics tools and resources have been developed for theoretical models, data on protein dynamics from computer simulations, impact of variants/mutations and molecular therapeutics. Here, we provide an overview of ongoing efforts on developing structural bioinformatics tools and resources for COVID-19 research. We also discuss the impact of these resources and structure-based studies, to understand various aspects of SARS-CoV-2 infection and therapeutic development. These include (i) understanding differences between SARS-CoV-2 and SARS-CoV, leading to increased infectivity of SARS-CoV-2, (ii) deciphering key residues in the SARS-CoV-2 involved in receptor-antibody recognition, (iii) analysis of variants in host proteins that affect host susceptibility to infection and (iv) analyses facilitating structure-based drug and vaccine design against SARS-CoV-2.
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Affiliation(s)
| | | | | | - Antoine Daina
- Molecular Modeling Group at SIB, Swiss Institute of Bioinformatics
| | | | - Vincent Zoete
- Department of Fundamental Oncology at the University of Lausanne and Group leader at SIB
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Abstract
Lysosomes offer a unique arrangement of degradative, exocytic, and signaling capabilities that make their continued function critical to cellular homeostasis. Lysosomes owe their function to the activity of lysosomal ion channels and transporters, which maintain concentration gradients of H+, K+, Ca2+, Na+, and Cl- across the lysosomal membrane. This review examines the contributions of lysosomal ion channels to lysosome function, showing how ion channel function is integral to degradation and autophagy, maintaining lysosomal membrane potential, controlling Ca2+ signaling, and facilitating exocytosis. Evidence of lysosome dysfunction in a variety of disease pathologies creates a need to understand how lysosomal ion channels contribute to lysosome dysfunction. For example, the loss of function of the TRPML1 Ca2+ lysosome channel in multiple lysosome storage diseases leads to lysosome dysfunction and disease pathogenesis while neurodegenerative diseases are marked by lysosome dysfunction caused by changes in ion channel activity through the TRPML1, TPC, and TMEM175 ion channels. Autoimmune disease is marked by dysregulated autophagy, which is dependent on the function of multiple lysosomal ion channels. Understanding the role of lysosomal ion channel activity in lysosome membrane permeability and NLRP3 inflammasome activation could provide valuable mechanistic insight into NLRP3 inflammasome-mediated diseases. Finally, this review seeks to show that understanding the role of lysosomal ion channels in lysosome dysfunction could give mechanistic insight into the efficacy of certain drug classes, specifically those that target the lysosome, such as cationic amphiphilic drugs.
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Affiliation(s)
- Rebekah L Kendall
- Department of Biomedical and Pharmaceutical Sciences, Center for Environmental Health Sciences, University of Montana, Missoula, MT, USA
| | - Andrij Holian
- Department of Biomedical and Pharmaceutical Sciences, Center for Environmental Health Sciences, University of Montana, Missoula, MT, USA
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Zhou JG, Donaubauer AJ, Frey B, Becker I, Rutzner S, Eckstein M, Sun R, Ma H, Schubert P, Schweizer C, Fietkau R, Deutsch E, Gaipl U, Hecht M. Prospective development and validation of a liquid immune profile-based signature (LIPS) to predict response of patients with recurrent/metastatic cancer to immune checkpoint inhibitors. J Immunother Cancer 2021; 9:jitc-2020-001845. [PMID: 33593828 PMCID: PMC7888377 DOI: 10.1136/jitc-2020-001845] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2020] [Indexed: 12/15/2022] Open
Abstract
Background The predictive power of novel biological markers for treatment response to immune checkpoint inhibitors (ICI) is still not satisfactory for the majority of patients with cancer. One should identify valid predictive markers in the peripheral blood, as this is easily available before and during treatment. The current interim analysis of patients of the ST-ICI cohort therefore focuses on the development and validation of a liquid immune profile-based signature (LIPS) to predict response of patients with metastatic cancer to ICI targeting the programmed cell death protein 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) axis. Methods A total of 104 patients were prospectively enrolled. 54 immune cell subsets were prospectively analyzed in patients’ peripheral blood by multicolor flow cytometry before treatment with ICI (pre-ICI; n=89), and after the first application of ICI (n=65). Pre-ICI, patients were randomly allocated to a training (n=56) and a validation cohort (n=33). Univariate Cox proportional hazards regression analysis and least absolute shrinkage and selection operator Cox model were used to create a predictive immune signature, which was also checked after the first ICI, to consider the dynamics of changes in the immune status. Results Whole blood samples were provided by 89 patients pre-ICI and by 65 patients after the first ICI. We identified a LIPS which is based on five immune cell subtypes: CD14high monocytes, CD8+/PD-1+ T cells, plasmacytoid dendritic cells, neutrophils, and CD3+/CD56+/CD16+ natural killer (NK)T cells. The signature achieved a high accuracy (C-index 0.74 vs 0.71) for predicting overall survival (OS) benefit in both the training and the validation cohort. In both cohorts, the low-risk group had significantly longer OS than the high-risk group (HR 0.26, 95% CI 0.12 to 0.56, p=0.00025; HR 0.30, 95% CI 0.10 to 0.91, p=0.024, respectively). Regarding the whole cohort, LIPS also predicted progression-free survival (PFS). The identified LIPS was not affected by clinicopathological features with the exception of brain metastases. NKT cells and neutrophils of the LIPS can be used as dynamic predictive biomarkers for OS and PFS after first administration of the ICI. Conclusion Our study identified a predictive LIPS for survival of patients with cancer treated with PD-1/PD-L1 ICI, which is based on immune cell subsets in the peripheral whole blood. Trial registration number NCT03453892.
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Affiliation(s)
- Jian-Guo Zhou
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany.,Department of Oncology, The Second Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Anna-Jasmina Donaubauer
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany
| | - Benjamin Frey
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany
| | - Ina Becker
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany
| | - Sandra Rutzner
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany
| | - Markus Eckstein
- Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany.,Institute of Pathology, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Roger Sun
- Department of Radiation Oncology, Gustave Roussy - CentraleSupélec - TheraPanacea Center of Artificial Intelligence in Radiation Therapy and Oncology, Villejuif, France.,Université Paris-Saclay, INSERM1030 Radiothérapie Moléculaire, Villejuif, France
| | - Hu Ma
- Department of Oncology, The Second Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Philipp Schubert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany
| | - Claudia Schweizer
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany
| | - Eric Deutsch
- Department of Radiation Oncology, Gustave Roussy - CentraleSupélec - TheraPanacea Center of Artificial Intelligence in Radiation Therapy and Oncology, Villejuif, France.,Université Paris-Saclay, INSERM1030 Radiothérapie Moléculaire, Villejuif, France
| | - Udo Gaipl
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Erlangen, Germany .,Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany
| | - Markus Hecht
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany
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Böck J, Krogsaeter E, Passon M, Chao YK, Sharma S, Grallert H, Peters A, Grimm C. Human genome diversity data reveal that L564P is the predominant TPC2 variant and a prerequisite for the blond hair associated M484L gain-of-function effect. PLoS Genet 2021; 17:e1009236. [PMID: 33465068 PMCID: PMC7845996 DOI: 10.1371/journal.pgen.1009236] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 01/29/2021] [Accepted: 10/29/2020] [Indexed: 12/29/2022] Open
Abstract
The endo-lysosomal two-pore channel (TPC2) has been established as an intracellular cation channel of significant physiological and pathophysiological relevance in recent years. For example, TPC2-/- mice show defects in cholesterol degradation, leading to hypercholesterinemia; TPC2 absence also results in mature-onset obesity, and a role in glucagon secretion and diabetes has been proposed. Infections with bacterial toxins or viruses e.g., cholera toxin or Ebola virus result in reduced infectivity rates in the absence of TPC2 or after pharmacological blockage, and TPC2-/- cancer cells lose their ability to migrate and metastasize efficiently. Finally, melanin production is affected by changes in hTPC2 activity, resulting in pigmentation defects and hair color variation. Here, we analyzed several publicly available genome variation data sets and identified multiple variations in the TPC2 protein in distinct human populations. Surprisingly, one variation, L564P, was found to be the predominant TPC2 isoform on a global scale. By applying endo-lysosomal patch-clamp electrophysiology, we found that L564P is a prerequisite for the previously described M484L gain-of-function effect that is associated with blond hair. Additionally, other gain-of-function variants with distinct geographical and ethnic distribution were discovered and functionally characterized. A meta-analysis of genome-wide association studies was performed, finding the polymorphisms to be associated with both distinct and overlapping traits. In sum, we present the first systematic analysis of variations in TPC2. We functionally characterized the most common variations and assessed their association with various disease traits. With TPC2 emerging as a novel drug target for the treatment of various diseases, this study provides valuable insights into ethnic and geographical distribution of TPC2 polymorphisms and their effects on channel activity.
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Affiliation(s)
- Julia Böck
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Einar Krogsaeter
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Marcel Passon
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Yu-Kai Chao
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Sapna Sharma
- Helmholtz Zentrum–Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Institute of Epidemiology, Neuherberg, Germany
| | - Harald Grallert
- Helmholtz Zentrum–Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Institute of Epidemiology, Neuherberg, Germany
| | - Annette Peters
- Helmholtz Zentrum–Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Institute of Epidemiology, Neuherberg, Germany
| | - Christian Grimm
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
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Thompson MJ, Baenziger JE. Ion channels as lipid sensors: from structures to mechanisms. Nat Chem Biol 2020; 16:1331-1342. [PMID: 33199909 DOI: 10.1038/s41589-020-00693-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 10/08/2020] [Indexed: 12/18/2022]
Abstract
Ion channels play critical roles in cellular function by facilitating the flow of ions across the membrane in response to chemical or mechanical stimuli. Ion channels operate in a lipid bilayer, which can modulate or define their function. Recent technical advancements have led to the solution of numerous ion channel structures solubilized in detergent and/or reconstituted into lipid bilayers, thus providing unprecedented insight into the mechanisms underlying ion channel-lipid interactions. Here, we describe how ion channel structures have evolved to respond to both lipid modulators and lipid activators to control the electrical activities of cells, highlighting diverse mechanisms and common themes.
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Affiliation(s)
- Mackenzie J Thompson
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - John E Baenziger
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada.
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76
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Gibb R, Franklinos LHV, Redding DW, Jones KE. Ecosystem perspectives are needed to manage zoonotic risks in a changing climate. BMJ 2020; 371:m3389. [PMID: 33187958 PMCID: PMC7662085 DOI: 10.1136/bmj.m3389] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Rory Gibb
- Centre for Biodiversity and Environment Research, Division of Biosciences, University College London, London, UK
| | - Lydia H V Franklinos
- Centre for Biodiversity and Environment Research, Division of Biosciences, University College London, London, UK
- Institute for Global Health, University College London, London, UK
| | - David W Redding
- Centre for Biodiversity and Environment Research, Division of Biosciences, University College London, London, UK
- Institute of Zoology, Zoological Society of London, London, UK
| | - Kate E Jones
- Centre for Biodiversity and Environment Research, Division of Biosciences, University College London, London, UK
- Institute of Zoology, Zoological Society of London, London, UK
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77
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Gil C, Ginex T, Maestro I, Nozal V, Barrado-Gil L, Cuesta-Geijo MÁ, Urquiza J, Ramírez D, Alonso C, Campillo NE, Martinez A. COVID-19: Drug Targets and Potential Treatments. J Med Chem 2020; 63:12359-12386. [PMID: 32511912 PMCID: PMC7323060 DOI: 10.1021/acs.jmedchem.0c00606] [Citation(s) in RCA: 290] [Impact Index Per Article: 72.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Indexed: 02/07/2023]
Abstract
Currently, humans are immersed in a pandemic caused by the emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which threatens public health worldwide. To date, no drug or vaccine has been approved to treat the severe disease caused by this coronavirus, COVID-19. In this paper, we will focus on the main virus-based and host-based targets that can guide efforts in medicinal chemistry to discover new drugs for this devastating disease. In principle, all CoV enzymes and proteins involved in viral replication and the control of host cellular machineries are potentially druggable targets in the search for therapeutic options for SARS-CoV-2. This Perspective provides an overview of the main targets from a structural point of view, together with reported therapeutic compounds with activity against SARS-CoV-2 and/or other CoVs. Also, the role of innate immune response to coronavirus infection and the related therapeutic options will be presented.
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Affiliation(s)
- Carmen Gil
- Centro de Investigaciones
Biológicas Margarita Salas (CSIC), Ramiro
de Maeztu 9, 28040 Madrid, Spain
| | - Tiziana Ginex
- Centro de Investigaciones
Biológicas Margarita Salas (CSIC), Ramiro
de Maeztu 9, 28040 Madrid, Spain
| | - Inés Maestro
- Centro de Investigaciones
Biológicas Margarita Salas (CSIC), Ramiro
de Maeztu 9, 28040 Madrid, Spain
| | - Vanesa Nozal
- Centro de Investigaciones
Biológicas Margarita Salas (CSIC), Ramiro
de Maeztu 9, 28040 Madrid, Spain
| | - Lucía Barrado-Gil
- Centro de Investigaciones
Biológicas Margarita Salas (CSIC), Ramiro
de Maeztu 9, 28040 Madrid, Spain
| | - Miguel Ángel Cuesta-Geijo
- Centro de Investigaciones
Biológicas Margarita Salas (CSIC), Ramiro
de Maeztu 9, 28040 Madrid, Spain
| | - Jesús Urquiza
- Department of Biotechnology,
Instituto Nacional de Investigación y
Tecnología Agraria y Alimentaria (INIA),
Ctra. de la Coruña km 7.5, 28040 Madrid,
Spain
| | - David Ramírez
- Instituto de Ciencias Biomédicas,
Universidad Autónoma de Chile,
Llano Subercaseaux 2801- piso 6, 7500912 Santiago,
Chile
| | - Covadonga Alonso
- Department of Biotechnology,
Instituto Nacional de Investigación y
Tecnología Agraria y Alimentaria (INIA),
Ctra. de la Coruña km 7.5, 28040 Madrid,
Spain
| | - Nuria E. Campillo
- Centro de Investigaciones
Biológicas Margarita Salas (CSIC), Ramiro
de Maeztu 9, 28040 Madrid, Spain
| | - Ana Martinez
- Centro de Investigaciones
Biológicas Margarita Salas (CSIC), Ramiro
de Maeztu 9, 28040 Madrid, Spain
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78
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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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79
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Schrecker M, Korobenko J, Hite RK. Cryo-EM structure of the lysosomal chloride-proton exchanger CLC-7 in complex with OSTM1. eLife 2020; 9:e59555. [PMID: 32749217 PMCID: PMC7440919 DOI: 10.7554/elife.59555] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 07/29/2020] [Indexed: 01/21/2023] Open
Abstract
The chloride-proton exchanger CLC-7 plays critical roles in lysosomal homeostasis and bone regeneration and its mutation can lead to osteopetrosis, lysosomal storage disease and neurological disorders. In lysosomes and the ruffled border of osteoclasts, CLC-7 requires a β-subunit, OSTM1, for stability and activity. Here, we present electron cryomicroscopy structures of CLC-7 in occluded states by itself and in complex with OSTM1, determined at resolutions up to 2.8 Å. In the complex, the luminal surface of CLC-7 is entirely covered by a dimer of the heavily glycosylated and disulfide-bonded OSTM1, which serves to protect CLC-7 from the degradative environment of the lysosomal lumen. OSTM1 binding does not induce large-scale rearrangements of CLC-7, but does have minor effects on the conformation of the ion-conduction pathway, potentially contributing to its regulatory role. These studies provide insights into the role of OSTM1 and serve as a foundation for understanding the mechanisms of CLC-7 regulation.
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Affiliation(s)
- Marina Schrecker
- Structural Biology Program, Memorial Sloan Kettering Cancer CenterNew YorkUnited States
| | - Julia Korobenko
- Structural Biology Program, Memorial Sloan Kettering Cancer CenterNew YorkUnited States
| | - Richard K Hite
- Structural Biology Program, Memorial Sloan Kettering Cancer CenterNew YorkUnited States
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80
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Milenkovic S, Bodrenko IV, Lagostena L, Gradogna A, Serra G, Bosin A, Carpaneto A, Ceccarelli M. The mechanism and energetics of a ligand-controlled hydrophobic gate in a mammalian two pore channel. Phys Chem Chem Phys 2020; 22:15664-15674. [PMID: 32618303 DOI: 10.1039/d0cp00805b] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In the last decade two-pore intracellular channels (TPCs) attracted the interest of researchers, still some key questions remain open. Their importance for vacuolar (plants) and endo-lysosomal (animals) function highlights them as a very attractive system to study, both theoretically and experimentally. Indicated as key players in the trafficking of the cell, today they are considered a new potential target for avoiding virus infections, including those from coronaviruses. A particular boost for theoretical examinations has been made with recent high-resolution X-ray and cryo-EM structures. These findings have opened the way for efficient and precise computational studies at the atomistic level. Here we report a set of multiscale-calculations performed on the mTPC1, a ligand- and voltage-gated sodium selective channel. The molecular dynamics and enhanced molecular dynamics simulations were used for a thorough analysis of the mammalian TPC1 behaviour in the presence and absence of the ligand molecule, with a special accent on the supposed bottleneck, the hydrophobic gate. Moreover, from the reconstructed free energy obtained from enhanced simulations, we have calculated the macroscopic conductance of sodium ions through the mTPC1, which we compared with measured single-channel conductance values. The hydrophobic gate works as a steric barrier and the key parameters are its flexibility and the dimension of the sodium first hydration shell.
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Affiliation(s)
- Stefan Milenkovic
- Department of Physics and IOM/CNR, University of Cagliari, 09042 Monserrato, Italy.
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81
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Molecular Basis for PI(3,5)P2 Recognition by SNX11, a Protein Involved in Lysosomal Degradation and Endosome Homeostasis Regulation. J Mol Biol 2020; 432:4750-4761. [DOI: 10.1016/j.jmb.2020.06.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 11/23/2022]
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82
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Gerndt S, Krogsaeter E, Patel S, Bracher F, Grimm C. Discovery of lipophilic two‐pore channel agonists. FEBS J 2020; 287:5284-5293. [DOI: 10.1111/febs.15432] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/14/2020] [Accepted: 05/27/2020] [Indexed: 11/27/2022]
Affiliation(s)
- Susanne Gerndt
- Department of Pharmacy – Center for Drug Research Ludwig‐Maximilians‐Universität Munich Germany
| | - Einar Krogsaeter
- Walther Straub Institute of Pharmacology and Toxicology Faculty of Medicine Ludwig‐Maximilians‐Universität Munich Germany
| | - Sandip Patel
- Department of Cell and Developmental Biology University College London London UK
| | - Franz Bracher
- Department of Pharmacy – Center for Drug Research Ludwig‐Maximilians‐Universität Munich Germany
| | - Christian Grimm
- Walther Straub Institute of Pharmacology and Toxicology Faculty of Medicine Ludwig‐Maximilians‐Universität Munich Germany
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83
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Davis LC, Morgan AJ, Galione A. NAADP-regulated two-pore channels drive phagocytosis through endo-lysosomal Ca 2+ nanodomains, calcineurin and dynamin. EMBO J 2020; 39:e104058. [PMID: 32510172 PMCID: PMC7360967 DOI: 10.15252/embj.2019104058] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/22/2020] [Accepted: 04/29/2020] [Indexed: 12/15/2022] Open
Abstract
Macrophages clear pathogens by phagocytosis and lysosomes that fuse with phagosomes are traditionally regarded as to a source of membranes and luminal degradative enzymes. Here, we reveal that endo-lysosomes act as platforms for a new phagocytic signalling pathway in which FcγR activation recruits the second messenger NAADP and thereby promotes the opening of Ca2+ -permeable two-pore channels (TPCs). Remarkably, phagocytosis is driven by these local endo-lysosomal Ca2+ nanodomains rather than global cytoplasmic or ER Ca2+ signals. Motile endolysosomes contact nascent phagosomes to promote phagocytosis, whereas endo-lysosome immobilization prevents it. We show that TPC-released Ca2+ rapidly activates calcineurin, which in turn dephosphorylates and activates the GTPase dynamin-2. Finally, we find that different endo-lysosomal Ca2+ channels play diverse roles, with TPCs providing a universal phagocytic signal for a wide range of particles and TRPML1 being only required for phagocytosis of large targets.
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Affiliation(s)
- Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, UK
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84
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Wiriyasermkul P, Moriyama S, Nagamori S. Membrane transport proteins in melanosomes: Regulation of ions for pigmentation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183318. [PMID: 32333855 PMCID: PMC7175901 DOI: 10.1016/j.bbamem.2020.183318] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/17/2020] [Accepted: 04/18/2020] [Indexed: 12/12/2022]
Abstract
Melanosomes are unique organelles in melanocytes that produce melanin, the pigment for skin, hair, and eye color. Tyrosinase is the essential and rate-limiting enzyme for melanin production, that strictly requires neutral pH for activity. pH maintenance is a result of the combinational function of multiple ion transport proteins. Thus, ion homeostasis in melanosomes is crucial for melanin synthesis. Defect of the ion transport system causes various pigmentation phenotypes, from mild effect to severe disorders such as albinism. In this review, we summarize the up-to-date knowledge of the ion transport system, such as transport function, structure, and the physiological roles and mechanisms of the ion transport proteins in melanosomes. In addition, we propose a model of melanosomal ion transport system-how the functional coupling of multiple transport proteins modulates and maintains ion homeostasis. We discuss melanin synthesis in terms of the ion transport system.
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Affiliation(s)
- Pattama Wiriyasermkul
- Department of Collaborative Research for Bio-Molecular Dynamics, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan
| | - Satomi Moriyama
- Department of Collaborative Research for Bio-Molecular Dynamics, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan
| | - Shushi Nagamori
- Department of Collaborative Research for Bio-Molecular Dynamics, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan.
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85
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Hammond GRV, Burke JE. Novel roles of phosphoinositides in signaling, lipid transport, and disease. Curr Opin Cell Biol 2020; 63:57-67. [PMID: 31972475 PMCID: PMC7247936 DOI: 10.1016/j.ceb.2019.12.007] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/12/2019] [Accepted: 12/14/2019] [Indexed: 12/22/2022]
Abstract
Phosphoinositides (PPIns) are lipid signaling molecules that act as master regulators of cellular signaling. Recent studies have revealed novel roles of PPIns in myriad cellular processes and multiple human diseases mediated by misregulation of PPIn signaling. This review will present a timely summary of recent discoveries in PPIn biology, specifically their role in regulating unexpected signaling pathways, modification of signaling outcomes downstream of integral membrane proteins, and novel roles in lipid transport. This has revealed new roles of PPIns in regulating membrane trafficking, immunity, cell polarity, and response to extracellular signals. A specific focus will be on novel opportunities to target PPIn metabolism for treatment of human diseases, including cancer, pathogen infection, developmental disorders, and immune disorders.
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Affiliation(s)
- Gerald R V Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA.
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8W 2Y2, Canada.
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86
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Gerndt S, Chen CC, Chao YK, Yuan Y, Burgstaller S, Scotto Rosato A, Krogsaeter E, Urban N, Jacob K, Nguyen ONP, Miller MT, Keller M, Vollmar AM, Gudermann T, Zierler S, Schredelseker J, Schaefer M, Biel M, Malli R, Wahl-Schott C, Bracher F, Patel S, Grimm C. Agonist-mediated switching of ion selectivity in TPC2 differentially promotes lysosomal function. eLife 2020; 9:54712. [PMID: 32167471 PMCID: PMC7108868 DOI: 10.7554/elife.54712] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/12/2020] [Indexed: 12/16/2022] Open
Abstract
Ion selectivity is a defining feature of a given ion channel and is considered immutable. Here we show that ion selectivity of the lysosomal ion channel TPC2, which is hotly debated (Calcraft et al., 2009; Guo et al., 2017; Jha et al., 2014; Ruas et al., 2015; Wang et al., 2012), depends on the activating ligand. A high-throughput screen identified two structurally distinct TPC2 agonists. One of these evoked robust Ca2+-signals and non-selective cation currents, the other weaker Ca2+-signals and Na+-selective currents. These properties were mirrored by the Ca2+-mobilizing messenger, NAADP and the phosphoinositide, PI(3,5)P2, respectively. Agonist action was differentially inhibited by mutation of a single TPC2 residue and coupled to opposing changes in lysosomal pH and exocytosis. Our findings resolve conflicting reports on the permeability and gating properties of TPC2 and they establish a new paradigm whereby a single ion channel mediates distinct, functionally-relevant ionic signatures on demand.
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Affiliation(s)
- Susanne Gerndt
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany.,Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Cheng-Chang Chen
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Yu-Kai Chao
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Yu Yuan
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Sandra Burgstaller
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Anna Scotto Rosato
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Einar Krogsaeter
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Nicole Urban
- Rudolf-Boehm-Institute for Pharmacology and Toxicology, Universität Leipzig, Leipzig, Germany
| | - Katharina Jacob
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Ong Nam Phuong Nguyen
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Meghan T Miller
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany.,Pharma Research and Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Marco Keller
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Angelika M Vollmar
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Susanna Zierler
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Johann Schredelseker
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany.,Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Michael Schaefer
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany.,Rudolf-Boehm-Institute for Pharmacology and Toxicology, Universität Leipzig, Leipzig, Germany
| | - Martin Biel
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | | | - Franz Bracher
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Sandip Patel
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Christian Grimm
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
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87
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Yan Y, He J, Feng Y, Lin P, Tao H, Huang SY. Challenges and opportunities of automated protein-protein docking: HDOCK server vs human predictions in CAPRI Rounds 38-46. Proteins 2020; 88:1055-1069. [PMID: 31994779 DOI: 10.1002/prot.25874] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 01/02/2020] [Accepted: 01/22/2020] [Indexed: 12/12/2022]
Abstract
Protein-protein docking plays an important role in the computational prediction of the complex structure between two proteins. For years, a variety of docking algorithms have been developed, as witnessed by the critical assessment of prediction interactions (CAPRI) experiments. However, despite their successes, many docking algorithms often require a series of manual operations like modeling structures from sequences, incorporating biological information, and selecting final models. The difficulties in these manual steps have significantly limited the applications of protein-protein docking, as most of the users in the community are nonexperts in docking. Therefore, automated docking like a web server, which can give a comparable performance to human docking protocol, is pressingly needed. As such, we have participated in the blind CAPRI experiments for Rounds 38-45 and CASP13-CAPRI challenge for Round 46 with both our HDOCK automated docking web server and human docking protocol. It was shown that our HDOCK server achieved an "acceptable" or higher CAPRI-rated model in the top 10 submitted predictions for 65.5% and 59.1% of the targets in the docking experiments of CAPRI and CASP13-CAPRI, respectively, which are comparable to 66.7% and 54.5% for human docking protocol. Similar trends can also be observed in the scoring experiments. These results validated our HDOCK server as an efficient automated docking protocol for nonexpert users. Challenges and opportunities of automated docking are also discussed.
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Affiliation(s)
- Yumeng Yan
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Jiahua He
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Yuyu Feng
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Peicong Lin
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Huanyu Tao
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Sheng-You Huang
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
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88
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Resting state structure of the hyperdepolarization activated two-pore channel 3. Proc Natl Acad Sci U S A 2020; 117:1988-1993. [PMID: 31924746 DOI: 10.1073/pnas.1915144117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Voltage-gated ion channels endow membranes with excitability and the means to propagate action potentials that form the basis of all neuronal signaling. We determined the structure of a voltage-gated sodium channel, two-pore channel 3 (TPC3), which generates ultralong action potentials. TPC3 is distinguished by activation only at extreme membrane depolarization (V50 ∼ +75 mV), in contrast to other TPCs and NaV channels that activate between -20 and 0 mV. We present electrophysiological evidence that TPC3 voltage activation depends only on voltage sensing domain 2 (VSD2) and that each of the three gating arginines in VSD2 reduces the activation threshold. The structure presents a chemical basis for sodium selectivity, and a constricted gate suggests a closed pore consistent with extreme voltage dependence. The structure, confirmed by our electrophysiology, illustrates the configuration of a bona fide resting state voltage sensor, observed without the need for any inhibitory ligand, and independent of any chemical or mutagenic alteration.
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89
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Zhang X, Chen W, Li P, Calvo R, Southall N, Hu X, Bryant-Genevier M, Feng X, Geng Q, Gao C, Yang M, Tang K, Ferrer M, Marugan JJ, Xu H. Agonist-specific voltage-dependent gating of lysosomal two-pore Na + channels. eLife 2019; 8:e51423. [PMID: 31825310 PMCID: PMC6905855 DOI: 10.7554/elife.51423] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/23/2019] [Indexed: 12/12/2022] Open
Abstract
Mammalian two-pore-channels (TPC1, 2; TPCN1, TPCN2) are ubiquitously- expressed, PI(3,5)P2-activated, Na+-selective channels in the endosomes and lysosomes that regulate luminal pH homeostasis, membrane trafficking, and Ebola viral infection. Whereas the channel activity of TPC1 is strongly dependent on membrane voltage, TPC2 lacks such voltage dependence despite the presence of the presumed 'S4 voltage-sensing' domains. By performing high-throughput screening followed by lysosomal electrophysiology, here we identified a class of tricyclic anti-depressants (TCAs) as small-molecule agonists of TPC channels. TCAs activate both TPC1 and TPC2 in a voltage-dependent manner, referred to as Lysosomal Na+ channel Voltage-dependent Activators (LyNa-VAs). We also identified another compound which, like PI(3,5)P2, activates TPC2 independent of voltage, suggesting the existence of agonist-specific gating mechanisms. Our identification of small-molecule TPC agonists should facilitate the studies of the cell biological roles of TPCs and can also readily explain the reported effects of TCAs in the modulation of autophagy and lysosomal functions.
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Affiliation(s)
- Xiaoli Zhang
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
| | - Wei Chen
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
| | - Ping Li
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
- Collaborative Innovation Center of Yangtze River Delta Region Green PharmaceuticalsZhejiang University of TechnologyHangzhouChina
| | - Raul Calvo
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Noel Southall
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Xin Hu
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Melanie Bryant-Genevier
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Xinghua Feng
- Collaborative Innovation Center of Yangtze River Delta Region Green PharmaceuticalsZhejiang University of TechnologyHangzhouChina
| | - Qi Geng
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
| | - Chenlang Gao
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
| | - Meimei Yang
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
- Department of NeurologyThe Fourth Hospital of Harbin Medical UniversityHarbinChina
| | - Kaiyuan Tang
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
| | - Marc Ferrer
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Juan Jose Marugan
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Haoxing Xu
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
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90
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Abstract
Of the established Ca2+-mobilizing messengers, NAADP is arguably the most tantalizing. It is the most potent, often efficacious at low nanomolar concentrations, and its receptors undergo dramatic desensitization. Recent studies have identified a new class of calcium-release channel, the two-pore channels (TPCs), as the likely targets for NAADP regulation, even though the effect may be indirect. These channels localized at endolysosomes, where they mediate local Ca2+ release, and have highlighted a new role of acidic organelles as targets for messenger-evoked Ca2+ mobilization. Three distinct roles of TPCs have been identified. The first is to effect local Ca2+ release that may play a role in endolysosomal function including vesicular fusion and trafficking. The second is to trigger global calcium release by recruiting Ca2+-induced Ca2+-release (CICR) channels at lysosomal-endoplasmic reticulum (ER) junctions. The third is to regulate plasma membrane excitability by the targeting of Ca2+ release from appropriately positioned subplasma membrane stores to regulate plasma membrane Ca2+-activated channels. In this review, I discuss the role of nicotinic acid adenine nucleotide diphosphate (NAADP)-mediated Ca2+ release from endolysosomal stores as a widespread trigger for intracellular calcium signaling mechanisms, and how studies of TPCs are beginning to enhance our understanding of the central role of lysosomes in Ca2+ signaling.
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Affiliation(s)
- Antony Galione
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
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91
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Senning EN. With PIPs, you get ZIPs and blips. J Gen Physiol 2019; 151:971-973. [PMID: 31235474 PMCID: PMC6683672 DOI: 10.1085/jgp.201912402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Senning discusses new research on the regulation of two-pore sodium channels by different phosphoinositide phosphates.
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Affiliation(s)
- Eric N. Senning
- Department of Neuroscience, University of Texas at Austin, Austin, TX
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92
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Shimomura T, Kubo Y. Phosphoinositides modulate the voltage dependence of two-pore channel 3. J Gen Physiol 2019; 151:986-1006. [PMID: 31182502 PMCID: PMC6683669 DOI: 10.1085/jgp.201812285] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 04/26/2019] [Accepted: 05/23/2019] [Indexed: 02/03/2023] Open
Abstract
Two-pore channels, or two-pore Na+ channels (TPCs), contain two homologous domains, each containing a functional unit typical of voltage-dependent cation channels. Each domain is considered to be responsible for either phosphoinositide (PI) binding or voltage sensing. Among the three members of the TPC family, TPC1 and TPC2 are activated by PI(3,5)P2, while TPC3 has been thought not to be affected by any PIs. Here, we report that TPC3 is sensitive to PI(3,4)P2 and PI(3,5)P2, but not to PI(4,5)P2, and that the extremely slow increase in TPC3 currents induced by depolarization in Xenopus oocytes is due to the production of PI(3,4)P2 Similarly to TPC1, the cluster of basic amino acid residues in domain I is critical for PI sensitivity, but with a slight variation that may allow TPC3 to be sensitive to both PI(3,4)P2 and PI(3,5)P2 We also found that TPC3 has a unique PI-dependent modulation mechanism of voltage dependence, which is achieved by a specific bridging interaction between domain I and domain II. Taken together, these findings show that TPC3 is a unique member of the TPC family that senses PIs and displays a strong coupling between PI binding and voltage-dependent gating.
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Affiliation(s)
- Takushi Shimomura
- Division of Biophysics and Neurobiology, National Institute for Physiological Sciences, Okazaki, Japan .,Department of Physiological Sciences, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Hayama, Japan
| | - Yoshihiro Kubo
- Division of Biophysics and Neurobiology, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Physiological Sciences, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Hayama, Japan
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