1
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Staudner T, Geiges L, Khamseekaew J, Sure F, Korbmacher C, Ilyaskin AV. Disease-associated missense mutations in the pore loop of polycystin-2 alter its ion channel function in a heterologous expression system. J Biol Chem 2024:107574. [PMID: 39009345 DOI: 10.1016/j.jbc.2024.107574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 06/20/2024] [Accepted: 07/03/2024] [Indexed: 07/17/2024] Open
Abstract
Polycystin-2 (PC2) is mutated in ∼15% of patients with autosomal dominant polycystic kidney disease (ADPKD). PC2 belongs to the family of transient receptor potential (TRP) channels and can function as homotetramer. We investigated whether three disease-associated mutations (F629S, C632R or R638C) localized in the channel's pore loop alter ion channel properties of human PC2 expressed in Xenopus laevis oocytes. Expression of wildtype (WT) PC2 typically resulted in small but measurable Na+ inward currents in the absence of extracellular divalent cations. These currents were no longer observed, when individual pore mutations were introduced in WT PC2. Similarly, Na+ inward currents mediated by the F604P gain-of-function (GOF) PC2 construct (PC2 F604P) were abolished by each of the three pore mutations. In contrast, when the mutations were introduced in another GOF construct, PC2 L677A N681A, only C632R had a complete loss-of-function effect, whereas significant residual Na+ inward currents were observed with F629S (∼15 %) and R638C (∼30 %). Importantly, the R638C mutation also abolished the Ca2+ permeability of PC2 L677A N681A and altered its monovalent cation selectivity. To elucidate the molecular mechanisms by which the R638C mutation affects channel function, molecular dynamics (MD) simulations were used in combination with functional experiments and site-directed mutagenesis. Our findings suggest that R638C stabilizes ionic interactions between Na+ ions and the selectivity filter residue D643. This probably explains the reduced monovalent cation conductance of the mutant channel. In summary, our data support the concept that altered ion channel properties of PC2 contribute to the pathogenesis of ADPKD.
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Affiliation(s)
- Tobias Staudner
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany
| | - Linda Geiges
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany
| | - Juthamas Khamseekaew
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany
| | - Florian Sure
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany
| | - Christoph Korbmacher
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany
| | - Alexandr V Ilyaskin
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany.
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2
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Hu M, Feng X, Liu Q, Liu S, Huang F, Xu H. The ion channels of endomembranes. Physiol Rev 2024; 104:1335-1385. [PMID: 38451235 DOI: 10.1152/physrev.00025.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 02/20/2024] [Accepted: 02/25/2024] [Indexed: 03/08/2024] Open
Abstract
The endomembrane system consists of organellar membranes in the biosynthetic pathway [endoplasmic reticulum (ER), Golgi apparatus, and secretory vesicles] as well as those in the degradative pathway (early endosomes, macropinosomes, phagosomes, autophagosomes, late endosomes, and lysosomes). These endomembrane organelles/vesicles work together to synthesize, modify, package, transport, and degrade proteins, carbohydrates, and lipids, regulating the balance between cellular anabolism and catabolism. Large ion concentration gradients exist across endomembranes: Ca2+ gradients for most endomembrane organelles and H+ gradients for the acidic compartments. Ion (Na+, K+, H+, Ca2+, and Cl-) channels on the organellar membranes control ion flux in response to cellular cues, allowing rapid informational exchange between the cytosol and organelle lumen. Recent advances in organelle proteomics, organellar electrophysiology, and luminal and juxtaorganellar ion imaging have led to molecular identification and functional characterization of about two dozen endomembrane ion channels. For example, whereas IP3R1-3 channels mediate Ca2+ release from the ER in response to neurotransmitter and hormone stimulation, TRPML1-3 and TMEM175 channels mediate lysosomal Ca2+ and H+ release, respectively, in response to nutritional and trafficking cues. This review aims to summarize the current understanding of these endomembrane channels, with a focus on their subcellular localizations, ion permeation properties, gating mechanisms, cell biological functions, and disease relevance.
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Affiliation(s)
- Meiqin Hu
- Department of Neurology and Department of Cardiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, People's Republic of China
- New Cornerstone Science Laboratory, Liangzhu Laboratory and School of Basic Medical Sciences, Zhejiang University, Hangzhou, People's Republic of China
| | - Xinghua Feng
- Department of Neurology and Department of Cardiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, People's Republic of China
- New Cornerstone Science Laboratory, Liangzhu Laboratory and School of Basic Medical Sciences, Zhejiang University, Hangzhou, People's Republic of China
| | - Qiang Liu
- New Cornerstone Science Laboratory, Liangzhu Laboratory and School of Basic Medical Sciences, Zhejiang University, Hangzhou, People's Republic of China
| | - Siyu Liu
- New Cornerstone Science Laboratory, Liangzhu Laboratory and School of Basic Medical Sciences, Zhejiang University, Hangzhou, People's Republic of China
| | - Fangqian Huang
- New Cornerstone Science Laboratory, Liangzhu Laboratory and School of Basic Medical Sciences, Zhejiang University, Hangzhou, People's Republic of China
| | - Haoxing Xu
- Department of Neurology and Department of Cardiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, People's Republic of China
- New Cornerstone Science Laboratory, Liangzhu Laboratory and School of Basic Medical Sciences, Zhejiang University, Hangzhou, People's Republic of China
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States
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3
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Yuan Y, Jaślan D, Rahman T, Bracher F, Grimm C, Patel S. Coordinating activation of endo-lysosomal two-pore channels and TRP mucolipins. J Physiol 2024; 602:1623-1636. [PMID: 38598430 DOI: 10.1113/jp283829] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 02/12/2024] [Indexed: 04/12/2024] Open
Abstract
Two-pore channels and TRP mucolipins are ubiquitous endo-lysosomal cation channels of pathophysiological relevance. Both are Ca2+-permeable and regulated by phosphoinositides, principally PI(3,5)P2. Accumulating evidence has uncovered synergistic channel activation by PI(3,5)P2 and endogenous metabolites such as the Ca2+ mobilizing messenger NAADP, synthetic agonists including approved drugs and physical cues such as voltage and osmotic pressure. Here, we provide an overview of this coordination.
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Affiliation(s)
- Yu Yuan
- Department of Cell and Developmental Biology, UCL, London, UK
| | - Dawid Jaślan
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilian University, Munich, Germany
| | - Taufiq Rahman
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Franz Bracher
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians University, Munich, Germany
| | - Christian Grimm
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilian University, Munich, Germany
- Immunology, Infection and Pandemic Research IIP, Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Frankfurt, Germany
| | - Sandip Patel
- Department of Cell and Developmental Biology, UCL, London, UK
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4
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Wang Z, Chen M, Su Q, Morais TDC, Wang Y, Nazginov E, Pillai AR, Qian F, Shi Y, Yu Y. Molecular and structural basis of the dual regulation of the polycystin-2 ion channel by small-molecule ligands. Proc Natl Acad Sci U S A 2024; 121:e2316230121. [PMID: 38483987 PMCID: PMC10962963 DOI: 10.1073/pnas.2316230121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 02/12/2024] [Indexed: 03/19/2024] Open
Abstract
Mutations in the PKD2 gene, which encodes the polycystin-2 (PC2, also called TRPP2) protein, lead to autosomal dominant polycystic kidney disease (ADPKD). As a member of the transient receptor potential (TRP) channel superfamily, PC2 functions as a non-selective cation channel. The activation and regulation of the PC2 channel are largely unknown, and direct binding of small-molecule ligands to this channel has not been reported. In this work, we found that most known small-molecule agonists of the mucolipin TRP (TRPML) channels inhibit the activity of the PC2_F604P, a gain-of-function mutant of the PC2 channel. However, two of them, ML-SA1 and SF-51, have dual regulatory effects, with low concentration further activating PC2_F604P, and high concentration leading to inactivation of the channel. With two cryo-electron microscopy (cryo-EM) structures, a molecular docking model, and mutagenesis results, we identified two distinct binding sites of ML-SA1 in PC2_F604P that are responsible for activation and inactivation, respectively. These results provide structural and functional insights into how ligands regulate PC2 channel function through unusual mechanisms and may help design compounds that are more efficient and specific in regulating the PC2 channel and potentially also for ADPKD treatment.
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Affiliation(s)
- Zhifei Wang
- Department of Biological Sciences, St. John’s University, Queens, NY11375
| | - Mengying Chen
- Research Center for Industries of the Future, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang province310024, China
- Westlake Laboratory of Life Sciences and Biomedicine, Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang province310024, China
- Beijing Frontier Research Center for Biological Structures, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Qiang Su
- Research Center for Industries of the Future, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang province310024, China
- Westlake Laboratory of Life Sciences and Biomedicine, Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang province310024, China
| | - Tiago D. C. Morais
- Department of Biological Sciences, St. John’s University, Queens, NY11375
| | - Yan Wang
- Department of Biological Sciences, St. John’s University, Queens, NY11375
| | - Elianna Nazginov
- Department of Biological Sciences, St. John’s University, Queens, NY11375
| | - Akhilraj R. Pillai
- Department of Biological Sciences, St. John’s University, Queens, NY11375
| | - Feng Qian
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD21201
| | - Yigong Shi
- Research Center for Industries of the Future, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang province310024, China
- Westlake Laboratory of Life Sciences and Biomedicine, Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang province310024, China
- Beijing Frontier Research Center for Biological Structures, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Yong Yu
- Department of Biological Sciences, St. John’s University, Queens, NY11375
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5
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Humer C, Radiskovic T, Horváti K, Lindinger S, Groschner K, Romanin C, Höglinger C. Bidirectional Allosteric Coupling between PIP 2 Binding and the Pore of the Oncochannel TRPV6. Int J Mol Sci 2024; 25:618. [PMID: 38203789 PMCID: PMC10779433 DOI: 10.3390/ijms25010618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 12/31/2023] [Accepted: 01/01/2024] [Indexed: 01/12/2024] Open
Abstract
The epithelial ion channel TRPV6 plays a pivotal role in calcium homeostasis. Channel function is intricately regulated at different stages, involving the lipid phosphatidylinositol-4,5-bisphosphate (PIP2). Given that dysregulation of TRPV6 is associated with various diseases, including different types of cancer, there is a compelling need for its pharmacological targeting. Structural studies provide insights on how TRPV6 is affected by different inhibitors, with some binding to sites else occupied by lipids. These include the small molecule cis-22a, which, however, also binds to and thereby blocks the pore. By combining calcium imaging, electrophysiology and optogenetics, we identified residues within the pore and the lipid binding site that are relevant for regulation by cis-22a and PIP2 in a bidirectional manner. Yet, mutation of the cytosolic pore exit reduced inhibition by cis-22a but preserved sensitivity to PIP2 depletion. Our data underscore allosteric communication between the lipid binding site and the pore and vice versa for most sites along the pore.
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Affiliation(s)
- Christina Humer
- Institute of Biophysics, Johannes Kepler University Linz, 4020 Linz, Austria; (C.H.); (T.R.); (C.R.)
| | - Tamara Radiskovic
- Institute of Biophysics, Johannes Kepler University Linz, 4020 Linz, Austria; (C.H.); (T.R.); (C.R.)
| | - Kata Horváti
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, 1117 Budapest, Hungary;
| | - Sonja Lindinger
- Institute of Biophysics, Johannes Kepler University Linz, 4020 Linz, Austria; (C.H.); (T.R.); (C.R.)
| | - Klaus Groschner
- Gottfried Schatz Research Center, Division of Biophysics, Medical University of Graz, 8010 Graz, Austria;
| | - Christoph Romanin
- Institute of Biophysics, Johannes Kepler University Linz, 4020 Linz, Austria; (C.H.); (T.R.); (C.R.)
| | - Carmen Höglinger
- Institute of Biophysics, Johannes Kepler University Linz, 4020 Linz, Austria; (C.H.); (T.R.); (C.R.)
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6
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Marini M, Titiz M, Souza Monteiro de Araújo D, Geppetti P, Nassini R, De Logu F. TRP Channels in Cancer: Signaling Mechanisms and Translational Approaches. Biomolecules 2023; 13:1557. [PMID: 37892239 PMCID: PMC10605459 DOI: 10.3390/biom13101557] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 10/29/2023] Open
Abstract
Ion channels play a crucial role in a wide range of biological processes, including cell cycle regulation and cancer progression. In particular, the transient receptor potential (TRP) family of channels has emerged as a promising therapeutic target due to its involvement in several stages of cancer development and dissemination. TRP channels are expressed in a large variety of cells and tissues, and by increasing cation intracellular concentration, they monitor mechanical, thermal, and chemical stimuli under physiological and pathological conditions. Some members of the TRP superfamily, namely vanilloid (TRPV), canonical (TRPC), melastatin (TRPM), and ankyrin (TRPA), have been investigated in different types of cancer, including breast, prostate, lung, and colorectal cancer. TRP channels are involved in processes such as cell proliferation, migration, invasion, angiogenesis, and drug resistance, all related to cancer progression. Some TRP channels have been mechanistically associated with the signaling of cancer pain. Understanding the cellular and molecular mechanisms by which TRP channels influence cancer provides new opportunities for the development of targeted therapeutic strategies. Selective inhibitors of TRP channels are under initial scrutiny in experimental animals as potential anti-cancer agents. In-depth knowledge of these channels and their regulatory mechanisms may lead to new therapeutic strategies for cancer treatment, providing new perspectives for the development of effective targeted therapies.
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Affiliation(s)
| | | | | | | | - Romina Nassini
- Department of Health Sciences, Clinical Pharmacology and Oncology Section, University of Florence, 50139 Florence, Italy; (M.M.); (M.T.); (D.S.M.d.A.); (P.G.); (F.D.L.)
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7
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Ma H, Xing F, Zhou Y, Yu P, Luo R, Xu J, Xiang Z, Rommens PM, Duan X, Ritz U. Design and fabrication of intracellular therapeutic cargo delivery systems based on nanomaterials: current status and future perspectives. J Mater Chem B 2023; 11:7873-7912. [PMID: 37551112 DOI: 10.1039/d3tb01008b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Intracellular cargo delivery, the introduction of small molecules, proteins, and nucleic acids into a specific targeted site in a biological system, is an important strategy for deciphering cell function, directing cell fate, and reprogramming cell behavior. With the advancement of nanotechnology, many researchers use nanoparticles (NPs) to break through biological barriers to achieving efficient targeted delivery in biological systems, bringing a new way to realize efficient targeted drug delivery in biological systems. With a similar size to many biomolecules, NPs possess excellent physical and chemical properties and a certain targeting ability after functional modification on the surface of NPs. Currently, intracellular cargo delivery based on NPs has emerged as an important strategy for genome editing regimens and cell therapy. Although researchers can successfully deliver NPs into biological systems, many of them are delivered very inefficiently and are not specifically targeted. Hence, the development of efficient, target-capable, and safe nanoscale drug delivery systems to deliver therapeutic substances to cells or organs is a major challenge today. In this review, on the basis of describing the research overview and classification of NPs, we focused on the current research status of intracellular cargo delivery based on NPs in biological systems, and discuss the current problems and challenges in the delivery process of NPs in biological systems.
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Affiliation(s)
- Hong Ma
- Department of Orthopedic Surgery, Orthopedic Research Institute, West China Hospital, Sichuan University, Chengdu, China.
| | - Fei Xing
- Department of Orthopedic Surgery, Orthopedic Research Institute, West China Hospital, Sichuan University, Chengdu, China.
| | - Yuxi Zhou
- Department of Periodontology, Justus-Liebig-University of Giessen, Ludwigstraße 23, 35392 Giessen, Germany
| | - Peiyun Yu
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany
| | - Rong Luo
- Department of Orthopedic Surgery, Orthopedic Research Institute, West China Hospital, Sichuan University, Chengdu, China.
| | - Jiawei Xu
- Department of Orthopedic Surgery, Orthopedic Research Institute, West China Hospital, Sichuan University, Chengdu, China.
| | - Zhou Xiang
- Department of Orthopedic Surgery, Orthopedic Research Institute, West China Hospital, Sichuan University, Chengdu, China.
| | - Pol Maria Rommens
- Department of Orthopaedics and Traumatology, Biomatics Group, University Medical Center of the Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany.
| | - Xin Duan
- Department of Orthopedic Surgery, Orthopedic Research Institute, West China Hospital, Sichuan University, Chengdu, China.
- Department of Orthopedic Surgery, The Fifth People's Hospital of Sichuan Province, Chengdu, China
| | - Ulrike Ritz
- Department of Orthopaedics and Traumatology, Biomatics Group, University Medical Center of the Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany.
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8
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Xu M, Zhong XZ, Huang P, Jaślan D, Wang P, Sun X, Weiden EM, EL Hiani Y, Grimm C, Dong XP. TRPML3/BK complex promotes autophagy and bacterial clearance by providing a positive feedback regulation of mTOR via PI3P. Proc Natl Acad Sci U S A 2023; 120:e2215777120. [PMID: 37585464 PMCID: PMC10450854 DOI: 10.1073/pnas.2215777120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 06/22/2023] [Indexed: 08/18/2023] Open
Abstract
TRPML3 is a Ca2+/Na+ release channel residing in both phagophores and endolysosomal membranes. It is activated by PI3P and PI3,5P2. Its activity can be enhanced by high luminal pH and by replacing luminal Na+ with K+. Here, we report that big-conductance Ca2+-activated potassium (BK) channels form a positive feedback loop with TRPML3. Ca2+ release via TRPML3 activates BK, which in turn facilitates TRPML3-mediated Ca2+ release, potentially through removing luminal Na+ inhibition. We further show that TRPML3/BK and mammalian target of rapamycin (mTOR) form another positive feedback loop to facilitate autophagy induction in response to nutrient starvation, i.e., mTOR inhibition upon nutrient starvation activates TRPML3/BK, and this further reduces mTOR activity, thereby increasing autophagy induction. Mechanistically, the feedback regulation between TRPML3/BK and mTOR is mediated by PI3P, an endogenous TRPML3 activator that is enriched in phagophores and is up-regulated by mTOR reduction. Importantly, bacterial infection activates TRPML3 in a BK-dependent manner, and both TRPML3 and BK are required for mTOR suppression and autophagy induction responding to bacterial infection. Suppressing either TRPML3 or BK helps bacteria survival whereas increasing either TRPML3 or BK favors bacterial clearance. Considering that TRPML3/BK is inhibited by low luminal pH but activated by high luminal pH and PI3P in phagophores, we suggest that TRPML3/BK and mTOR form a positive feedback loop via PI3P to ensure efficient autophagy induction in response to nutrient deprivation and bacterial infection. Our study reveals a role of TRPML3-BK coupling in controlling cellular homeostasis and intracellular bacterial clearance via regulating mTOR signaling.
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Affiliation(s)
- Mengnan Xu
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Xi Zoë Zhong
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Peng Huang
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
- Chongming Hospital, Shanghai University of Medicine and Health Sciences, Shanghai202150, China
| | - Dawid Jaślan
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich80336, Germany
| | - Pingping Wang
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Xue Sun
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
- Department of Developmental Cell Biology, China Medical University, Shenbei New District, Shenyang110122, China
| | - Eva-Maria Weiden
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich80336, Germany
| | - Yassine EL Hiani
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Christian Grimm
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich80336, Germany
- Immunology, Infection and Pandemic Research, Fraunhofer Institute for Translational Medicine and Pharmacology, Munich80799, Germany
| | - Xian-Ping Dong
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
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9
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Wang Y, Wang Z, Pavel MA, Ng C, Kashyap P, Li B, Morais TDC, Ulloa GA, Yu Y. The diverse effects of pathogenic point mutations on ion channel activity of a gain-of-function polycystin-2. J Biol Chem 2023; 299:104674. [PMID: 37028763 PMCID: PMC10192930 DOI: 10.1016/j.jbc.2023.104674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 02/27/2023] [Accepted: 03/06/2023] [Indexed: 04/08/2023] Open
Abstract
Autosomal dominant polycystic kidney disease is caused by mutations in PKD1 or PKD2 genes. The latter encodes polycystin-2 (PC2, also known as TRPP2), a member of the transient receptor potential ion channel family. Despite most pathogenic mutations in PKD2 being truncation variants, there are also many point mutations, which cause small changes in protein sequences but dramatic changes in the in vivo function of PC2. How these mutations affect PC2 ion channel function is largely unknown. In this study, we systematically tested the effects of 31 point mutations on the ion channel activity of a gain-of-function PC2 mutant, PC2_F604P, expressed in Xenopus oocytes. The results show that all mutations in the transmembrane domains and channel pore region, and most mutations in the extracellular tetragonal opening for polycystins domain, are critical for PC2_F604P channel function. In contrast, the other mutations in the tetragonal opening for polycystins domain and most mutations in the C-terminal tail cause mild or no effects on channel function as assessed in Xenopus oocytes. To understand the mechanism of these effects, we have discussed possible conformational consequences of these mutations based on the cryo-EM structures of PC2. The results help gain insight into the structure and function of the PC2 ion channel and the molecular mechanism of pathogenesis caused by these mutations.
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Affiliation(s)
- Yan Wang
- Department of Biological Sciences, St. John's University, Queens, New York, USA
| | - Zhifei Wang
- Department of Biological Sciences, St. John's University, Queens, New York, USA
| | - Mahmud Arif Pavel
- Department of Biological Sciences, St. John's University, Queens, New York, USA
| | - Courtney Ng
- Department of Biological Sciences, St. John's University, Queens, New York, USA
| | - Parul Kashyap
- Department of Biological Sciences, St. John's University, Queens, New York, USA
| | - Bin Li
- Department of Biological Sciences, St. John's University, Queens, New York, USA
| | - Tiago D C Morais
- Department of Biological Sciences, St. John's University, Queens, New York, USA
| | - Gabriella A Ulloa
- Department of Biological Sciences, St. John's University, Queens, New York, USA
| | - Yong Yu
- Department of Biological Sciences, St. John's University, Queens, New York, USA.
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10
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Zuo Y, Chai Y, Liu X, Gao Z, Jin X, Wang F, Bai Y, Zheng Z. A ratiometric fluorescent probe based on spiropyran in situ switching for tracking dynamic changes of lysosomal autophagy and anticounterfeiting. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 291:122338. [PMID: 36657288 DOI: 10.1016/j.saa.2023.122338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/28/2022] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
Autophagy is the controlled breakdown of cellular components that dysfunctional or nonessential, and the decomposition products are further recycled and synthesized for the normal physiological activities of cells. Lysosomal autophagy has been implicated in cancer, neurological disorders, Parkinson's disease, etc. Therefore, it is necessary to develop a fluorescent probe that can clearly describe the process of lysosomal autophagy. However, there are currently limited fluorescent probes for ratiometric monitoring of the autophagic process in dual channels. To solve this problem, a fluorescent probe based on spiropyran with lysosomal targeting and pH response for ratiometric monitoring the autophagy process of lysosomes were designed. The sensitive response of the probe to pH in vitro was verified by UV and fluorescence spectrum tests. Meanwhile, the probe demonstrated the ability to monitor the intracellular pH fluctuations. In addition, the application of Lyso-SD in the field of anti-counterfeiting has been proposed based on the obvious photoluminescence ability of Lyso-SD under UV irradiation.
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Affiliation(s)
- Yujing Zuo
- Tianjin Key Laboratory of Composite & Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China; Ningbo Yinzhou Chinaust Automobile Fittings Corp. Ltd., Ningbo 315142, China
| | - Yanfu Chai
- Tianjin Key Laboratory of Composite & Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China; School of Mechanical and Electrical Engineering, Shaoxing University, Shaoxing 312000, China; Ningbo Yinzhou Chinaust Automobile Fittings Corp. Ltd., Ningbo 315142, China.
| | - Xiaofei Liu
- Tianjin Key Laboratory of Composite & Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Zhiming Gao
- Tianjin Key Laboratory of Composite & Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Xiaofeng Jin
- Ningbo Yinzhou Chinaust Automobile Fittings Corp. Ltd., Ningbo 315142, China
| | - Feng Wang
- Ningbo Yinzhou Chinaust Automobile Fittings Corp. Ltd., Ningbo 315142, China
| | - Yongjie Bai
- Ningbo Yinzhou Chinaust Automobile Fittings Corp. Ltd., Ningbo 315142, China
| | - Zhijun Zheng
- Ningbo Yinzhou Chinaust Automobile Fittings Corp. Ltd., Ningbo 315142, China
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11
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Abstract
This chapter explores the existing structural and functional studies on the endo-lysosomal channel TRPML1 and its analogs TRPML2, TRPML3. These channels represent the mucolipin subfamily of the TRP channel superfamily comprising important roles in sensory physiology, ion homeostasis, and signal transduction. Since 2016, numerous structures have been determined for all three members using either cryo-EM or X-ray crystallography. These studies along with recent functional analysis have considerably strengthened our knowledge on TRPML channels and its related endo-lysosomal function. This chapter, together with relevant reports in other chapters from this handbook, provides an informative and detailed tool to study the endo-lysosomal cation channels.
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Affiliation(s)
- Michael Fine
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Xiaochun Li
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
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12
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Lugmayr W, Kotov V, Goessweiner-Mohr N, Wald J, DiMaio F, Marlovits TC. StarMap: a user-friendly workflow for Rosetta-driven molecular structure refinement. Nat Protoc 2023; 18:239-264. [PMID: 36323866 DOI: 10.1038/s41596-022-00757-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/08/2022] [Indexed: 01/13/2023]
Abstract
Cryogenic electron microscopy (cryo-EM) data represent density maps of macromolecular systems at atomic or near-atomic resolution. However, building and refining 3D atomic models by using data from cryo-EM maps is not straightforward and requires significant hands-on experience and manual intervention. We recently developed StarMap, an easy-to-use interface between the popular structural display program ChimeraX and Rosetta, a powerful molecular modeling engine. StarMap offers a general approach for refining structural models of biological macromolecules into cryo-EM density maps by combining Monte Carlo sampling with local density-guided optimization, Rosetta-based all-atom refinement and real-space B-factor calculations in a straightforward workflow. StarMap includes options for structural symmetry, local refinements and independent model validation. The overall quality of the refinement and the structure resolution is then assessed via analytical outputs, such as magnification calibration (pixel size calibration) and Fourier shell correlations. Z-scores reported by StarMap provide an easily interpretable indicator of the goodness of fit for each residue and can be plotted to evaluate structural models and improve local residue refinements, as well as to identify flexible regions and potentially functional sites in large macromolecular complexes. The protocol requires general computer skills, without the need for coding expertise, because most parts of the workflow can be operated by clicking tabs within the ChimeraX graphical user interface. Time requirements for the model refinement depend on the size and quality of the input data; however, this step can typically be completed within 1 d. The analytical parts of the workflow are completed within minutes.
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Affiliation(s)
- Wolfgang Lugmayr
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany.,CSSB Centre for Structural Systems Biology, Hamburg, Germany.,Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany.,Research Institute of Molecular Pathology (IMP), Vienna, Austria.,Institute for Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria
| | - Vadim Kotov
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany.,CSSB Centre for Structural Systems Biology, Hamburg, Germany.,Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany.,Research Institute of Molecular Pathology (IMP), Vienna, Austria.,Institute for Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria.,Evotec SE, Hamburg, Germany
| | - Nikolaus Goessweiner-Mohr
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany.,CSSB Centre for Structural Systems Biology, Hamburg, Germany.,Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany.,Research Institute of Molecular Pathology (IMP), Vienna, Austria.,Institute for Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria.,Johannes Kepler University, Institute of Biophysics, Linz, Austria
| | - Jiri Wald
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany.,CSSB Centre for Structural Systems Biology, Hamburg, Germany.,Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany.,Research Institute of Molecular Pathology (IMP), Vienna, Austria.,Institute for Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria
| | - Frank DiMaio
- University of Washington, Department of Biochemistry, Seattle, WA, USA
| | - Thomas C Marlovits
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany. .,CSSB Centre for Structural Systems Biology, Hamburg, Germany. .,Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany. .,Research Institute of Molecular Pathology (IMP), Vienna, Austria. .,Institute for Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria.
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13
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Yelshanskaya MV, Sobolevsky AI. Ligand-Binding Sites in Vanilloid-Subtype TRP Channels. Front Pharmacol 2022; 13:900623. [PMID: 35652046 PMCID: PMC9149226 DOI: 10.3389/fphar.2022.900623] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 04/06/2022] [Indexed: 02/02/2023] Open
Abstract
Vanilloid-subfamily TRP channels TRPV1-6 play important roles in various physiological processes and are implicated in numerous human diseases. Advances in structural biology, particularly the "resolution revolution" in cryo-EM, have led to breakthroughs in molecular characterization of TRPV channels. Structures with continuously improving resolution uncover atomic details of TRPV channel interactions with small molecules and protein-binding partners. Here, we provide a classification of structurally characterized binding sites in TRPV channels and discuss the progress that has been made by structural biology combined with mutagenesis, functional recordings, and molecular dynamics simulations toward understanding of the molecular mechanisms of ligand action. Given the similarity in structural architecture of TRP channels, 16 unique sites identified in TRPV channels may be shared between TRP channel subfamilies, although the chemical identity of a particular ligand will likely depend on the local amino-acid composition. The characterized binding sites and molecular mechanisms of ligand action create a diversity of druggable targets to aid in the design of new molecules for tuning TRP channel function in disease conditions.
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Affiliation(s)
| | - Alexander I. Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, United States
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14
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Identification of putative binding interface of PI(3,5)P2 lipid on rice black-streaked dwarf virus (RBSDV) P10 protein. Virology 2022; 570:81-95. [DOI: 10.1016/j.virol.2022.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/15/2022] [Accepted: 03/27/2022] [Indexed: 11/18/2022]
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15
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Chen CC, Krogsaeter E, Kuo CY, Huang MC, Chang SY, Biel M. Endolysosomal cation channels point the way towards precision medicine of cancer and infectious diseases. Biomed Pharmacother 2022; 148:112751. [PMID: 35240524 DOI: 10.1016/j.biopha.2022.112751] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 11/02/2022] Open
Abstract
Infectious diseases and cancer are among the key medical challenges that humankind is facing today. A growing amount of evidence suggests that ion channels in the endolysosomal system play a crucial role in the pathology of both groups of diseases. The development of advanced patch-clamp technologies has allowed us to directly characterize ion fluxes through endolysosomal ion channels in their native environments. Endolysosomes are essential organelles for intracellular transport, digestion and metabolism, and maintenance of homeostasis. The endolysosomal ion channels regulate the function of the endolysosomal system through four basic mechanisms: calcium release, control of membrane potential, pH change, and osmolarity regulation. In this review, we put particular emphasis on the endolysosomal cation channels, including TPC2 and TRPML2, which are particularly important in monocyte function. We discuss existing endogenous and synthetic ligands of these channels and summarize current knowledge of their impact on channel activity and function in different cell types. Moreover, we summarize recent findings on the importance of TPC2 and TRPML2 channels as potential drug targets for the prevention and treatment of the emerging infectious diseases and cancer.
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Affiliation(s)
- Cheng-Chang Chen
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
| | | | - Ching-Ying Kuo
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Min-Chuan Huang
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Sui-Yuan Chang
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Martin Biel
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
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16
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Current Methods to Unravel the Functional Properties of Lysosomal Ion Channels and Transporters. Cells 2022; 11:cells11060921. [PMID: 35326372 PMCID: PMC8946281 DOI: 10.3390/cells11060921] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/04/2022] [Accepted: 03/05/2022] [Indexed: 02/07/2023] Open
Abstract
A distinct set of channels and transporters regulates the ion fluxes across the lysosomal membrane. Malfunctioning of these transport proteins and the resulting ionic imbalance is involved in various human diseases, such as lysosomal storage disorders, cancer, as well as metabolic and neurodegenerative diseases. As a consequence, these proteins have stimulated strong interest for their suitability as possible drug targets. A detailed functional characterization of many lysosomal channels and transporters is lacking, mainly due to technical difficulties in applying the standard patch-clamp technique to these small intracellular compartments. In this review, we focus on current methods used to unravel the functional properties of lysosomal ion channels and transporters, stressing their advantages and disadvantages and evaluating their fields of applicability.
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17
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Structural mechanism of allosteric activation of TRPML1 by PI(3,5)P 2 and rapamycin. Proc Natl Acad Sci U S A 2022; 119:2120404119. [PMID: 35131932 PMCID: PMC8851561 DOI: 10.1073/pnas.2120404119] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2022] [Indexed: 12/22/2022] Open
Abstract
Rapamycin is a specific inhibitor of mammalian target of rapamycin (mTOR). Rapamycin can also activate transient receptor potential mucolipin 1 (TRPML1), a phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2]–gated lysosomal cation channel whose loss-of-function mutations directly cause mucolipidosis type IV disease. We determined the high-resolution cryoelectron microscopy structures of TRPML1 in various ligand-bound states, including the open TRPML1 in complex with PI(3,5)P2 and a rapamycin analog at 2.1 Å. These structures reveal how rapamycin and PI(3,5)P2 bind at two distinct sites and allosterically activate the channel. Considering the high potency of TRPML1 activation by rapamycin and PI(3,5)P2, it is conceivable that some pharmacological effects from the therapeutic use of rapamycin may come from the TRPML1-dependent mechanism rather than mTOR inhibition. Transient receptor potential mucolipin 1 (TRPML1) is a Ca2+-permeable, nonselective cation channel ubiquitously expressed in the endolysosomes of mammalian cells and its loss-of-function mutations are the direct cause of type IV mucolipidosis (MLIV), an autosomal recessive lysosomal storage disease. TRPML1 is a ligand-gated channel that can be activated by phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2] as well as some synthetic small-molecule agonists. Recently, rapamycin has also been shown to directly bind and activate TRPML1. Interestingly, both PI(3,5)P2 and rapamycin have low efficacy in channel activation individually but together they work cooperatively and activate the channel with high potency. To reveal the structural basis underlying the synergistic activation of TRPML1 by PI(3,5)P2 and rapamycin, we determined the high-resolution cryoelectron microscopy (cryo-EM) structures of the mouse TRPML1 channel in various states, including apo closed, PI(3,5)P2-bound closed, and PI(3,5)P2/temsirolimus (a rapamycin analog)-bound open states. These structures, combined with electrophysiology, elucidate the molecular details of ligand binding and provide structural insight into how the TRPML1 channel integrates two distantly bound ligand stimuli and facilitates channel opening.
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18
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Cai R, Chen XZ. Roles of Intramolecular Interactions in the Regulation of TRP Channels. Rev Physiol Biochem Pharmacol 2022; 186:29-56. [PMID: 35882668 DOI: 10.1007/112_2022_74] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The transient receptor potential (TRP) channels, classified into six (-A, -V, -P, -C, -M, -ML, -N and -Y) subfamilies, are important membrane sensors and mediators of diverse stimuli including pH, light, mechano-force, temperature, pain, taste, and smell. The mammalian TRP superfamily of 28 members share similar membrane topology with six membrane-spanning helices (S1-S6) and cytosolic N-/C-terminus. Abnormal function or expression of TRP channels is associated with cancer, skeletal dysplasia, immunodeficiency, and cardiac, renal, and neuronal diseases. The majority of TRP members share common functional regulators such as phospholipid PIP2, 2-aminoethoxydiphenyl borate (2-APB), and cannabinoid, while other ligands are more specific, such as allyl isothiocyanate (TRPA1), vanilloids (TRPV1), menthol (TRPM8), ADP-ribose (TRPM2), and ML-SA1 (TRPML1). The mechanisms underlying the gating and regulation of TRP channels remain largely unclear. Recent advances in cryogenic electron microscopy provided structural insights into 19 different TRP channels which all revealed close proximity of the C-terminus with the N-terminus and intracellular S4-S5 linker. Further studies found that some highly conserved residues in these regions of TRPV, -P, -C and -M members mediate functionally critical intramolecular interactions (i.e., within one subunit) between these regions. This review provides an overview on (1) intramolecular interactions in TRP channels and their effect on channel function; (2) functional roles of interplays between PIP2 (and other ligands) and TRP intramolecular interactions; and (3) relevance of the ligand-induced modulation of intramolecular interaction to diseases.
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Affiliation(s)
- Ruiqi Cai
- Program in Cell Biology, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, ON, Canada.,Department of Physiology, Membrane Protein Disease Research Group, University of Alberta, Edmonton, AB, Canada
| | - Xing-Zhen Chen
- Department of Physiology, Membrane Protein Disease Research Group, University of Alberta, Edmonton, AB, Canada.
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19
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Gan N, Jiang Y. Structural biology of cation channels important for lysosomal calcium release. Cell Calcium 2022; 101:102519. [PMID: 34952412 PMCID: PMC8752501 DOI: 10.1016/j.ceca.2021.102519] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 01/03/2023]
Abstract
Calcium is one of the most important second messengers in cells. The uptake and release of calcium ions are conducted by channels and transporters. Inside a eukaryotic cell, calcium is stored in intracellular organelles including the endoplasmic reticulum (ER), mitochondrion, and lysosome. Lysosomes are acid membrane-bounded organelles serving as the crucial degradation and recycling center of the cell. Lysosomes involve in multiple important signaling events, including nutrient sensing, lipid metabolism, and trafficking. Hitherto, two lysosomal cation channel families have been suggested to function as calcium release channels, namely the Two-pore Channel (TPC) family, and the Transient Receptor Potential Channel Mucolipin (TRPML) family. Additionally, a few plasma membrane calcium channels have also been found in the lysosomal membrane under certain circumstances. In this review, we will discuss the structural mechanism of the cation channels that may be important for lysosomal calcium release, primarily focusing on the TPCs and TRPMLs.
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Affiliation(s)
- Ninghai Gan
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390 USA,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390 USA
| | - Youxing Jiang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390 USA,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390 USA
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20
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Song X, Li J, Tian M, Zhu H, Hu X, Zhang Y, Cao Y, Ye H, McCormick PJ, Zeng B, Fu Y, Duan J, Zhang J. Cryo-EM structure of mouse TRPML2 in lipid nanodiscs. J Biol Chem 2021; 298:101487. [PMID: 34915027 PMCID: PMC8808176 DOI: 10.1016/j.jbc.2021.101487] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 11/27/2022] Open
Abstract
In mammalians, transient receptor potential mucolipin ion channels (TRPMLs) exhibit variable permeability to cations such as Ca2+, Fe2+, Zn2+, and Na+, and can be activated by the phosphoinositide PI(3,5)P2 in the endolysosomal system. Loss or dysfunction of TRPMLs has been implicated in lysosomal storage disorders, infectious diseases, and metabolic diseases. TRPML2 has recently been identified as a mechanosensitive and hypotonicity-sensitive channel in endolysosomal organelles, which distinguishes it from TRPML1 and TRPML3. However, the molecular and gating mechanism of TRPML2 remains elusive. Here, we present the cryo-EM structure of the full-length mouse TRPML2 in lipid nanodiscs at 3.14 Å resolution. The TRPML2 homo-tetramer structure at pH 7.4 in the apo state reveals an inactive conformation and some unique features of the extracytosolic/luminal domain and voltage sensor-like domain that have implications for the ion-conducting pathway. This structure enables new comparisons between the different subgroups of TRPML channels with available structures and provides structural insights into the conservation and diversity of TRPML channels. These comparisons have broad implications for understanding a variety of molecular mechanisms of TRPMLs in different pH conditions, including with and without bound agonists and antagonists.
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Affiliation(s)
- Xiaojing Song
- School of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, 330031, China
| | - Jian Li
- College of Pharmaceutical Sciences, Ganan Medical University, Ganzhou, 341000, China
| | - Miao Tian
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Huaiyi Zhu
- Human Aging Research Institute, School of Life Sciences, Nanchang University, Nanchang, Jiangxi, 330031, China
| | - Xiaohui Hu
- School of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, 330031, China
| | - Yuting Zhang
- School of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, 330031, China
| | - Yanru Cao
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Heyang Ye
- College of Pharmaceutical Sciences, Ganan Medical University, Ganzhou, 341000, China
| | - Peter J McCormick
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - Bo Zeng
- Key Laboratory of Medical Electrophysiology, Ministry of Education & Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, China
| | - Yang Fu
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.
| | - Jingjing Duan
- Human Aging Research Institute, School of Life Sciences, Nanchang University, Nanchang, Jiangxi, 330031, China.
| | - Jin Zhang
- School of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, 330031, China.
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21
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Zhao Y, McVeigh BM, Moiseenkova-Bell VY. Structural Pharmacology of TRP Channels. J Mol Biol 2021; 433:166914. [PMID: 33676926 PMCID: PMC8338738 DOI: 10.1016/j.jmb.2021.166914] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 12/15/2022]
Abstract
Transient receptor potential (TRP) ion channels are a super-family of ion channels that mediate transmembrane cation flux with polymodal activation, ranging from chemical to physical stimuli. Furthermore, due to their ubiquitous expression and role in human diseases, they serve as potential pharmacological targets. Advances in cryo-EM TRP channel structural biology has revealed general, as well as diverse, architectural elements and regulatory sites among TRP channel subfamilies. Here, we review the endogenous and pharmacological ligand-binding sites of TRP channels and their regulatory mechanisms.
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Affiliation(s)
- Yaxian Zhao
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bridget M McVeigh
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Vera Y Moiseenkova-Bell
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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22
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Structural basis for Ca 2+ activation of the heteromeric PKD1L3/PKD2L1 channel. Nat Commun 2021; 12:4871. [PMID: 34381056 PMCID: PMC8357825 DOI: 10.1038/s41467-021-25216-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/23/2021] [Indexed: 02/07/2023] Open
Abstract
The heteromeric complex between PKD1L3, a member of the polycystic kidney disease (PKD) protein family, and PKD2L1, also known as TRPP2 or TRPP3, has been a prototype for mechanistic characterization of heterotetrametric TRP-like channels. Here we show that a truncated PKD1L3/PKD2L1 complex with the C-terminal TRP-fold fragment of PKD1L3 retains both Ca2+ and acid-induced channel activities. Cryo-EM structures of this core heterocomplex with or without supplemented Ca2+ were determined at resolutions of 3.1 Å and 3.4 Å, respectively. The heterotetramer, with a pseudo-symmetric TRP architecture of 1:3 stoichiometry, has an asymmetric selectivity filter (SF) guarded by Lys2069 from PKD1L3 and Asp523 from the three PKD2L1 subunits. Ca2+-entrance to the SF vestibule is accompanied by a swing motion of Lys2069 on PKD1L3. The S6 of PKD1L3 is pushed inward by the S4-S5 linker of the nearby PKD2L1 (PKD2L1-III), resulting in an elongated intracellular gate which seals the pore domain. Comparison of the apo and Ca2+-loaded complexes unveils an unprecedented Ca2+ binding site in the extracellular cleft of the voltage-sensing domain (VSD) of PKD2L1-III, but not the other three VSDs. Structure-guided mutagenic studies support this unconventional site to be responsible for Ca2+-induced channel activation through an allosteric mechanism.
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23
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Schmiege P, Fine M, Li X. Atomic insights into ML-SI3 mediated human TRPML1 inhibition. Structure 2021; 29:1295-1302.e3. [PMID: 34171299 DOI: 10.1016/j.str.2021.06.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/28/2021] [Accepted: 06/04/2021] [Indexed: 11/19/2022]
Abstract
Transient receptor potential mucolipin 1 (TRPML1) regulates lysosomal calcium signaling, lipid trafficking, and autophagy-related processes. This channel is regulated by phosphoinositides and the low pH environment of the lysosome, maintaining calcium levels essential for proper lysosomal function. Recently, several small molecules specifically targeting the TRPML family have been demonstrated to modulate channel activity. One of these, a synthetic antagonist ML-SI3, can prevent lysosomal calcium efflux and has been reported to block downstream TRPML1-mediated induction of autophagy. Here, we report a cryo-electron microscopy structure of human TRPML1 with ML-SI3 at 2.9-Å resolution. ML-SI3 binds to the hydrophobic cavity created by S5, S6, and PH1, the same cavity where the synthetic agonist ML-SA1 binds. Electrophysiological characterizations show that ML-SI3 can compete with ML-SA1, blocking channel activation yet does not inhibit PI(3,5)P2-dependent activation of the channel. Consequently, this work provides molecular insight into how ML-SI3 and native lipids regulate TRPML1 activity.
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Affiliation(s)
- Philip Schmiege
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael Fine
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Xiaochun Li
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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24
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Cao E. Structural mechanisms of transient receptor potential ion channels. J Gen Physiol 2021; 152:133640. [PMID: 31972006 PMCID: PMC7054860 DOI: 10.1085/jgp.201811998] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 01/03/2020] [Indexed: 12/26/2022] Open
Abstract
Transient receptor potential (TRP) ion channels are evolutionarily ancient sensory proteins that detect and integrate a wide range of physical and chemical stimuli. TRP channels are fundamental for numerous biological processes and are therefore associated with a multitude of inherited and acquired human disorders. In contrast to many other major ion channel families, high-resolution structures of TRP channels were not available before 2013. Remarkably, however, the subsequent “resolution revolution” in cryo-EM has led to an explosion of TRP structures in the last few years. These structures have confirmed that TRP channels assemble as tetramers and resemble voltage-gated ion channels in their overall architecture. But beyond the relatively conserved transmembrane core embedded within the lipid bilayer, each TRP subtype appears to be endowed with a unique set of soluble domains that may confer diverse regulatory mechanisms. Importantly, TRP channel structures have revealed sites and mechanisms of action of numerous synthetic and natural compounds, as well as those for endogenous ligands such as lipids, Ca2+, and calmodulin. Here, I discuss these recent findings with a particular focus on the conserved transmembrane region and how these structures may help to rationally target this important class of ion channels for the treatment of numerous human conditions.
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Affiliation(s)
- Erhu Cao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT
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25
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Schwickert K, Andrzejewski M, Grabowsky S, Schirmeister T. Synthesis, X-ray Structure Determination, and Comprehensive Photochemical Characterization of (Trifluoromethyl)diazirine-Containing TRPML1 Ligands. J Org Chem 2021; 86:6169-6183. [PMID: 33835801 DOI: 10.1021/acs.joc.0c02993] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Potential (trifluoromethyl)diazirine-based TRPML1 ion channel ligands were designed and synthesized, and their structures were determined by single-crystal X-ray diffraction analysis. Photoactivation studies via 19F NMR spectroscopy and HPLC-MS analysis revealed distinct kinetical characteristics in selected solvents and favorable photochemical properties in an aqueous buffer. These photoactivatable TRPML activators represent useful and valuable tools for TRPML photoaffinity labeling combined with mass spectrometry.
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Affiliation(s)
- Kevin Schwickert
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University Mainz, Staudinger Weg 5, 55128 Mainz, Germany
| | - Michał Andrzejewski
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Simon Grabowsky
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Tanja Schirmeister
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University Mainz, Staudinger Weg 5, 55128 Mainz, Germany
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26
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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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27
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Amphipathic environments for determining the structure of membrane proteins by single-particle electron cryo-microscopy. Q Rev Biophys 2021; 54:e6. [PMID: 33785082 DOI: 10.1017/s0033583521000044] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Over the past decade, the structural biology of membrane proteins (MPs) has taken a new turn thanks to epoch-making technical progress in single-particle electron cryo-microscopy (cryo-EM) as well as to improvements in sample preparation. The present analysis provides an overview of the extent and modes of usage of the various types of surfactants for cryo-EM studies. Digitonin, dodecylmaltoside, protein-based nanodiscs, lauryl maltoside-neopentyl glycol, glyco-diosgenin, and amphipols (APols) are the most popular surfactants at the vitrification step. Surfactant exchange is frequently used between MP purification and grid preparation, requiring extensive optimization each time the study of a new MP is undertaken. The variety of both the surfactants and experimental approaches used over the past few years bears witness to the need to continue developing innovative surfactants and optimizing conditions for sample preparation. The possibilities offered by novel APols for EM applications are discussed.
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28
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Goretzki B, Guhl C, Tebbe F, Harder JM, Hellmich UA. Unstructural Biology of TRP Ion Channels: The Role of Intrinsically Disordered Regions in Channel Function and Regulation. J Mol Biol 2021; 433:166931. [PMID: 33741410 DOI: 10.1016/j.jmb.2021.166931] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 03/02/2021] [Accepted: 03/06/2021] [Indexed: 12/13/2022]
Abstract
The first genuine high-resolution single particle cryo-electron microscopy structure of a membrane protein determined was a transient receptor potential (TRP) ion channel, TRPV1, in 2013. This methodical breakthrough opened up a whole new world for structural biology and ion channel aficionados alike. TRP channels capture the imagination due to the sheer endless number of tasks they carry out in all aspects of animal physiology. To date, structures of at least one representative member of each of the six mammalian TRP channel subfamilies as well as of a few non-mammalian families have been determined. These structures were instrumental for a better understanding of TRP channel function and regulation. However, all of the TRP channel structures solved so far are incomplete since they miss important information about highly flexible regions found mostly in the channel N- and C-termini. These intrinsically disordered regions (IDRs) can represent between a quarter to almost half of the entire protein sequence and act as important recruitment hubs for lipids and regulatory proteins. Here, we analyze the currently available TRP channel structures with regard to the extent of these "missing" regions and compare these findings to disorder predictions. We discuss select examples of intra- and intermolecular crosstalk of TRP channel IDRs with proteins and lipids as well as the effect of splicing and post-translational modifications, to illuminate their importance for channel function and to complement the prevalently discussed structural biology of these versatile and fascinating proteins with their equally relevant 'unstructural' biology.
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Affiliation(s)
- Benedikt Goretzki
- Faculty of Chemistry and Earth Sciences, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich-Schiller-University, Humboldtstrasse 10, 07743 Jena, Germany; Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany
| | - Charlotte Guhl
- Faculty of Chemistry and Earth Sciences, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich-Schiller-University, Humboldtstrasse 10, 07743 Jena, Germany; Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany; TransMED - Mainz Research School of Translational Medicine, Johannes Gutenberg-University, University Medical Center, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Frederike Tebbe
- Faculty of Chemistry and Earth Sciences, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich-Schiller-University, Humboldtstrasse 10, 07743 Jena, Germany; Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany
| | - Jean-Martin Harder
- Faculty of Chemistry and Earth Sciences, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich-Schiller-University, Humboldtstrasse 10, 07743 Jena, Germany
| | - Ute A Hellmich
- Faculty of Chemistry and Earth Sciences, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich-Schiller-University, Humboldtstrasse 10, 07743 Jena, Germany; Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany; TransMED - Mainz Research School of Translational Medicine, Johannes Gutenberg-University, University Medical Center, Langenbeckstr. 1, 55131 Mainz, Germany; Cluster of Excellence Balance of the Microverse, Friedrich-Schiller-University, 07743 Jena, Germany.
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29
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Ji C, McCulloch CA. TRPV4 integrates matrix mechanosensing with Ca 2+ signaling to regulate extracellular matrix remodeling. FEBS J 2020; 288:5867-5887. [PMID: 33300268 DOI: 10.1111/febs.15665] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/23/2020] [Indexed: 12/23/2022]
Abstract
In healthy connective tissues, mechanosensors trigger the generation of Ca2+ signals, which enable cells to maintain the structure of the fibrillar collagen matrix through actomyosin contractile forces. Transient receptor potential vanilloid type 4 (TRPV4) is a mechanosensitive Ca2+ -permeable channel that, when expressed in cell-matrix adhesions of the plasma membrane, regulates extracellular matrix (ECM) remodeling. In high prevalence disorders such as fibrosis and tumor metastasis, dysregulated matrix remodeling is associated with disruptions of Ca2+ homeostasis and TRPV4 function. Here, we consider that ECM polymers transmit cell-activating mechanical signals to TRPV4 in cell adhesions. When activated, TRPV4 regulates fibrillar collagen remodeling, thereby altering the mechanical properties of the ECM. In this review, we integrate functionally connected processes of matrix remodeling to highlight how TRPV4 in cell adhesions and matrix mechanics are reciprocally regulated through Ca2+ signaling.
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Affiliation(s)
- Chenfan Ji
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, ON, Canada
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30
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Walsh S, Izquierdo-Serra M, Acosta S, Edo A, Lloret M, Moret R, Bosch E, Oliva B, Bertranpetit J, Fernández-Fernández JM. Adaptive selection drives TRPP3 loss-of-function in an Ethiopian population. Sci Rep 2020; 10:20999. [PMID: 33268808 PMCID: PMC7710729 DOI: 10.1038/s41598-020-78081-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 11/20/2020] [Indexed: 11/15/2022] Open
Abstract
TRPP3 (also called PKD2L1) is a nonselective, cation-permeable channel activated by multiple stimuli, including extracellular pH changes. TRPP3 had been considered a candidate for sour sensor in humans, due to its high expression in a subset of tongue receptor cells detecting sour, along with its membership to the TRP channel family known to function as sensory receptors. Here, we describe the functional consequences of two non-synonymous genetic variants (R278Q and R378W) found to be under strong positive selection in an Ethiopian population, the Gumuz. Electrophysiological studies and 3D modelling reveal TRPP3 loss-of-functions produced by both substitutions. R278Q impairs TRPP3 activation after alkalinisation by mislocation of H+ binding residues at the extracellular polycystin mucolipin domain. R378W dramatically reduces channel activity by altering conformation of the voltage sensor domain and hampering channel transition from closed to open state. Sour sensitivity tests in R278Q/R378W carriers argue against both any involvement of TRPP3 in sour detection and the role of such physiological process in the reported evolutionary positive selection past event.
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Affiliation(s)
- Sandra Walsh
- Institut de Biologia Evolutiva (UPF-CSIC), Universitat Pompeu Fabra, Dr. Aiguader, 88, 08003, Barcelona, Catalonia, Spain
| | - Mercè Izquierdo-Serra
- Laboratory of Molecular Physiology, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, 08003, Barcelona, Spain
| | - Sandra Acosta
- Institut de Biologia Evolutiva (UPF-CSIC), Universitat Pompeu Fabra, Dr. Aiguader, 88, 08003, Barcelona, Catalonia, Spain
| | - Albert Edo
- Laboratory of Molecular Physiology, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, 08003, Barcelona, Spain
| | - María Lloret
- Laboratory of Molecular Physiology, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, 08003, Barcelona, Spain
| | - Roser Moret
- Institut de Biologia Evolutiva (UPF-CSIC), Universitat Pompeu Fabra, Dr. Aiguader, 88, 08003, Barcelona, Catalonia, Spain
| | - Elena Bosch
- Institut de Biologia Evolutiva (UPF-CSIC), Universitat Pompeu Fabra, Dr. Aiguader, 88, 08003, Barcelona, Catalonia, Spain.,Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), 43206, Reus, Spain
| | - Baldo Oliva
- Structural Bioinformatics Lab, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, 08003, Barcelona, Spain
| | - Jaume Bertranpetit
- Institut de Biologia Evolutiva (UPF-CSIC), Universitat Pompeu Fabra, Dr. Aiguader, 88, 08003, Barcelona, Catalonia, Spain.
| | - José Manuel Fernández-Fernández
- Laboratory of Molecular Physiology, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, 08003, Barcelona, Spain.
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31
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Ha K, Nobuhara M, Wang Q, Walker RV, Qian F, Schartner C, Cao E, Delling M. The heteromeric PC-1/PC-2 polycystin complex is activated by the PC-1 N-terminus. eLife 2020; 9:60684. [PMID: 33164752 PMCID: PMC7728438 DOI: 10.7554/elife.60684] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/06/2020] [Indexed: 12/28/2022] Open
Abstract
Mutations in the polycystin proteins, PC-1 and PC-2, result in autosomal dominant polycystic kidney disease (ADPKD) and ultimately renal failure. PC-1 and PC-2 enrich on primary cilia, where they are thought to form a heteromeric ion channel complex. However, a functional understanding of the putative PC-1/PC-2 polycystin complex is lacking due to technical hurdles in reliably measuring its activity. Here we successfully reconstitute the PC-1/PC-2 complex in the plasma membrane of mammalian cells and show that it functions as an outwardly rectifying channel. Using both reconstituted and ciliary polycystin channels, we further show that a soluble fragment generated from the N-terminal extracellular domain of PC-1 functions as an intrinsic agonist that is necessary and sufficient for channel activation. We thus propose that autoproteolytic cleavage of the N-terminus of PC-1, a hotspot for ADPKD mutations, produces a soluble ligand in vivo. These findings establish a mechanistic framework for understanding the role of PC-1/PC-2 heteromers in ADPKD and suggest new therapeutic strategies that would expand upon the limited symptomatic treatments currently available for this progressive, terminal disease. On the surface of most animal and other eukaryotic cells are small rod-like protrusions known as primary cilia. Each cilium is encased by a specialized membrane which is enriched in protein complexes that help the cell sense its local environment. Some of these complexes help transport ions in out of the cell, while others act as receptors that receive chemical signals called ligands. A unique ion channel known as the polycystin complex is able to perform both of these roles as it contains a receptor called PC-1 in addition to an ion channel called PC-2. Various mutations in the genes that code for PC-1 and PC-2 can result in autosomal dominant polycystic kidney disease (ADPKD), which is the most common monogenetic disease in humans. However, due to the small size of primary cilia – which are less than a thousandth of a millimeter thick – little is known about how polycystin complexes are regulated and how mutations lead to ADPKD. To overcome this barrier, Ha et al. modified kidney cells grown in the lab so that PC-1 and PC-2 form a working channel in the plasma membrane which surrounds the entire cell. As the body of a cell is around 10,000 times bigger than the cilium, this allowed the movement of ions across the polycystin complex to be studied using conventional techniques. Experiments using this newly developed assay revealed that a region at one of the ends of the PC-1 protein, named the C-type lectin domain, is essential for stimulating polycystin complexes. Ha et al. found that this domain of PC-1 is able to cut itself from the protein complex. Further experiments showed that when fragments of PC-1, which contain the C-type lectin domain, are no longer bound to the membrane, they can activate the polycystin channels in cilia as well as the plasma membrane. This suggests that this region of PC-1 may also act as a secreted ligand that can activate other polycystin channels. Some of the genetic mutations that cause ADPKD likely disrupt the activity of the polycystin complex and reduce its ability to transport ions across the cilia membrane. Therefore, the cell assay created in this study could be used to screen for small molecules that can restore the activity of these ion channels in patients with ADPKD.
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Affiliation(s)
- Kotdaji Ha
- Department of Physiology, University of California, San Francisco, San Francisco, United States
| | - Mai Nobuhara
- Department of Physiology, University of California, San Francisco, San Francisco, United States
| | - Qinzhe Wang
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, United States
| | - Rebecca V Walker
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, United States
| | - Feng Qian
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, United States
| | - Christoph Schartner
- Department of Physiology, University of California, San Francisco, San Francisco, United States
| | - Erhu Cao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, United States
| | - Markus Delling
- Department of Physiology, University of California, San Francisco, San Francisco, United States
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32
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Chen CC, Krogsaeter E, Butz ES, Li Y, Puertollano R, Wahl-Schott C, Biel M, Grimm C. TRPML2 is an osmo/mechanosensitive cation channel in endolysosomal organelles. SCIENCE ADVANCES 2020; 6:6/46/eabb5064. [PMID: 33177082 PMCID: PMC7673730 DOI: 10.1126/sciadv.abb5064] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 09/24/2020] [Indexed: 05/12/2023]
Abstract
Endolysosomes are dynamic, intracellular compartments, regulating their surface-to-volume ratios to counteract membrane swelling or shrinkage caused by osmotic challenges upon tubulation and vesiculation events. While osmosensitivity has been extensively described on the plasma membrane, the mechanisms underlying endolysosomal surface-to-volume ratio changes and identities of involved ion channels remain elusive. Endolysosomes mediate endocytosis, exocytosis, cargo transport, and sorting of material for recycling or degradation. We demonstrate the endolysosomal cation channel TRPML2 to be hypotonicity/mechanosensitive, a feature crucial to its involvement in fast-recycling processes of immune cells. We demonstrate that the phosphoinositide binding pocket is required for TRPML2 hypotonicity-sensitivity, as substitution of L314 completely abrogates hypotonicity-sensitivity. Last, the hypotonicity-insensitive TRPML2 mutant L314R slows down the fast recycling pathway, corroborating the functional importance of hypotonicity-sensitive TRPML2. Our results highlight TRPML2 as an accelerator of endolysosomal trafficking by virtue of its hypotonicity-sensitivity, with implications in immune cell surveillance and viral trafficking.
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Affiliation(s)
- Cheng-Chang Chen
- 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
| | - Elisabeth S Butz
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Yanfen Li
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Rosa Puertollano
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | | | - Martin Biel
- 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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33
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Two-pore and TRPML cation channels: Regulators of phagocytosis, autophagy and lysosomal exocytosis. Pharmacol Ther 2020; 220:107713. [PMID: 33141027 DOI: 10.1016/j.pharmthera.2020.107713] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 10/19/2020] [Indexed: 02/07/2023]
Abstract
The old Greek saying "Panta Rhei" ("everything flows") is true for all life and all living things in general. It also becomes nicely evident when looking closely into cells. There, material from the extracellular space is taken up by endocytic processes and transported to endosomes where it is sorted either for recycling or degradation. Cargo is also packaged for export through exocytosis involving the Golgi network, lysosomes and other organelles. Everything in this system is in constant motion and many proteins are necessary to coordinate transport along the different intracellular pathways to avoid chaos. Among these proteins are ion channels., in particular TRPML channels (mucolipins) and two-pore channels (TPCs) which reside on endosomal and lysosomal membranes to speed up movement between organelles, e.g. by regulating fusion and fission; they help readjust pH and osmolarity changes due to such processes, or they promote exocytosis of export material. Pathophysiologically, these channels are involved in neurodegenerative, metabolic, retinal and infectious diseases, cancer, pigmentation defects, and immune cell function, and thus have been proposed as novel pharmacological targets, e.g. for the treatment of lysosomal storage disorders, Duchenne muscular dystrophy, or different types of cancer. Here, we discuss the similarities but also differences of TPCs and TRPMLs in regulating phagocytosis, autophagy and lysosomal exocytosis, and we address the contradictions and open questions in the field relating to the roles TPCs and TRPMLs play in these different processes.
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34
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Huffer KE, Aleksandrova AA, Jara-Oseguera A, Forrest LR, Swartz KJ. Global alignment and assessment of TRP channel transmembrane domain structures to explore functional mechanisms. eLife 2020; 9:e58660. [PMID: 32804077 PMCID: PMC7431192 DOI: 10.7554/elife.58660] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 07/31/2020] [Indexed: 12/20/2022] Open
Abstract
The recent proliferation of published TRP channel structures provides a foundation for understanding the diverse functional properties of this important family of ion channel proteins. To facilitate mechanistic investigations, we constructed a structure-based alignment of the transmembrane domains of 120 TRP channel structures. Comparison of structures determined in the absence or presence of activating stimuli reveals similar constrictions in the central ion permeation pathway near the intracellular end of the S6 helices, pointing to a conserved cytoplasmic gate and suggesting that most available structures represent non-conducting states. Comparison of the ion selectivity filters toward the extracellular end of the pore supports existing hypotheses for mechanisms of ion selectivity. Also conserved to varying extents are hot spots for interactions with hydrophobic ligands, lipids and ions, as well as discrete alterations in helix conformations. This analysis therefore provides a framework for investigating the structural basis of TRP channel gating mechanisms and pharmacology, and, despite the large number of structures included, reveals the need for additional structural data and for more functional studies to establish the mechanistic basis of TRP channel function.
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Affiliation(s)
- Katherine E Huffer
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Diseases and Stroke, National Institutes of HealthBethesdaUnited States
| | - Antoniya A Aleksandrova
- Computational Structural Biology Section, Porter Neuroscience Research Center, National Institute of Neurological Diseases and Stroke, National Institutes of HealthBethesdaUnited States
| | - Andrés Jara-Oseguera
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Diseases and Stroke, National Institutes of HealthBethesdaUnited States
| | - Lucy R Forrest
- Computational Structural Biology Section, Porter Neuroscience Research Center, National Institute of Neurological Diseases and Stroke, National Institutes of HealthBethesdaUnited States
| | - Kenton J Swartz
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Diseases and Stroke, National Institutes of HealthBethesdaUnited States
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35
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Zheng X, Fu Z, Su D, Zhang Y, Li M, Pan Y, Li H, Li S, Grassucci RA, Ren Z, Hu Z, Li X, Zhou M, Li G, Frank J, Yang J. Mechanism of ligand activation of a eukaryotic cyclic nucleotide-gated channel. Nat Struct Mol Biol 2020; 27:625-634. [PMID: 32483338 PMCID: PMC7354226 DOI: 10.1038/s41594-020-0433-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/10/2020] [Indexed: 01/21/2023]
Abstract
Cyclic nucleotide-gated (CNG) channels convert cyclic nucleotide (CN) binding and unbinding into electrical signals in sensory receptors and neurons. The molecular conformational changes underpinning ligand activation are largely undefined. We report both closed- and open-state atomic cryo-EM structures of a full-length Caenorhabditis elegans cyclic GMP-activated channel TAX-4, reconstituted in lipid nanodiscs. These structures, together with computational and functional analyses and a mutant channel structure, reveal a double-barrier hydrophobic gate formed by two S6 amino acids in the central cavity. cGMP binding produces global conformational changes that open the cavity gate located ~52 Å away but do not alter the structure of the selectivity filter-the commonly presumed activation gate. Our work provides mechanistic insights into the allosteric gating and regulation of CN-gated and nucleotide-modulated channels and CNG channel-related channelopathies.
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Affiliation(s)
- Xiangdong Zheng
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA,These authors contributed equally to this work
| | - Ziao Fu
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA,These authors contributed equally to this work
| | - Deyuan Su
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Chinese Academy of Sciences, Kunming 650223, China,These authors contributed equally to this work
| | - Yuebin Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Minghui Li
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA,Current address: HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Yaping Pan
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Huan Li
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Shufang Li
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA,Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Robert A. Grassucci
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Zhenning Ren
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zhengshan Hu
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Xueming Li
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Ming Zhou
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Guohui Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Joachim Frank
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA,Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Jian Yang
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA,Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Chinese Academy of Sciences, Kunming 650223, China
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36
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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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37
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Lyu L, Jin X, Li Z, Liu S, Li Y, Su R, Su H. TBBPA regulates calcium-mediated lysosomal exocytosis and thereby promotes invasion and migration in hepatocellular carcinoma. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 192:110255. [PMID: 32018154 DOI: 10.1016/j.ecoenv.2020.110255] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/22/2020] [Accepted: 01/26/2020] [Indexed: 06/10/2023]
Abstract
Tetrabromobisphenol A (TBBPA) and its derivatives are the common flame-retardants that may increase the risk of development of many types of cancers, including liver cancer. However, the effects of TBBPA in the development and progression of liver cancer remains unknown. This study investigated the potential effects of TBBPA on a metastatic phenotype of hepatocellular carcinoma cell line-HepG2. Our results revealed that TBBPA significantly promoted the migration and invasion via affecting the number and distribution of lysosomes in HepG2 cells in a dose-dependent manner. Moreover, TBBPA decreased the intracellular protein levels of Beta-Hexosaminidase (HEXB), Cathepsin B (CTSB) and Cathepsin D (CTSD) while increased the extracellular CTSB and CTSD. It entailed that TBBPA exposure could promote the lysosomal exocytosis in cancer cells. The reversal results were obtained after adding lysosomal exocytosis inhibitor vacuolin-1. Docking results suggested that TBBPA could bind to TRPML1. It was consistent with the binding position of agonist ML-SA1. TRPML1 knockdown significantly decreased the invasion and migration, and the results were reversed when TBBPA was added. The results were indicated that TRPML1 was critical in lysosomal exocytosis. In addition, our results showed that TBBPA-TRPML1 complex regulated the calcium-mediated lysosomal exocytosis, thereby promoting the metastasis in liver cancer cells. It was expected that our data could provide important basis for understanding the molecular mechanism(s) of TBBPA promoting invasion and migration of hepatoma cells and give rise to profound concerns of TBBPA exposure on human health.
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Affiliation(s)
- Liang Lyu
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Wucheng Road 92, Taiyuan Shanxi Prov, 030006, Taiyuan, China.
| | - Xiaoting Jin
- Institutes of Biomedical Sciences, Shanxi University, Wucheng Road 92, Taiyuan Shanxi Prov, 030006, Taiyuan, China.
| | - Zhuoyu Li
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Wucheng Road 92, Taiyuan Shanxi Prov, 030006, Taiyuan, China; School of Life Science, Shanxi University, Wucheng Road 92, Taiyuan Shanxi Prov, 030006, Taiyuan, China.
| | - Sha Liu
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Jiefang nan Road 85, Taiyuan Shanxi Prov, 030001, Taiyuan, China.
| | - Yi Li
- Department of Computer Science, Technische Universität Darmstadt, Hochschulstraße 10, 64289, Darmstadt, Germany.
| | - Ruijun Su
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Wucheng Road 92, Taiyuan Shanxi Prov, 030006, Taiyuan, China.
| | - Huilan Su
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Wucheng Road 92, Taiyuan Shanxi Prov, 030006, Taiyuan, China.
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Yelshanskaya MV, Nadezhdin KD, Kurnikova MG, Sobolevsky AI. Structure and function of the calcium-selective TRP channel TRPV6. J Physiol 2020; 599:2673-2697. [PMID: 32073143 DOI: 10.1113/jp279024] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 02/03/2020] [Indexed: 12/23/2022] Open
Abstract
Epithelial calcium channel TRPV6 is a member of the vanilloid subfamily of TRP channels that is permeable to cations and highly selective to Ca2+ ; it shows constitutive activity regulated negatively by Ca2+ and positively by phosphoinositol and cholesterol lipids. In this review, we describe the molecular structure of TRPV6 and discuss how its structural elements define its unique functional properties. High Ca2+ selectivity of TRPV6 originates from the narrow selectivity filter, where Ca2+ ions are directly coordinated by a ring of anionic aspartate side chains. Divalent cations Ca2+ and Ba2+ permeate TRPV6 pore according to the knock-off mechanism, while tight binding of Gd3+ to the aspartate ring blocks the channel and prevents Na+ from permeating the pore. The iris-like channel opening is accompanied by an α-to-π helical transition in the pore-lining transmembrane helix S6. As a result of this transition, the intracellular halves of the S6 helices bend and rotate by about 100 deg, exposing different residues to the channel pore in the open and closed states. Channel opening is also associated with changes in occupancy of the transmembrane domain lipid binding sites. The inhibitor 2-aminoethoxydiphenyl borate (2-APB) binds to TRPV6 in a pocket formed by the cytoplasmic half of the S1-S4 transmembrane helical bundle and shifts open-closed channel equilibrium towards the closed state by outcompeting lipids critical for activation. Ca2+ inhibits TRPV6 via binding to calmodulin (CaM), which mediates Ca2+ -dependent inactivation. The TRPV6-CaM complex exhibits 1:1 stoichiometry; one TRPV6 tetramer binds both CaM lobes, which adopt a distinct head-to-tail arrangement. The CaM C-terminal lobe plugs the channel through a unique cation-π interaction by inserting the side chain of lysine K115 into a tetra-tryptophan cage at the ion channel pore intracellular entrance. Recent studies of TRPV6 structure and function described in this review advance our understanding of the role of this channel in physiology and pathophysiology and inform new therapeutic design.
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Affiliation(s)
- Maria V Yelshanskaya
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168th Street, New York, NY, 10032, USA
| | - Kirill D Nadezhdin
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168th Street, New York, NY, 10032, USA
| | - Maria G Kurnikova
- Chemistry Department, Carnegie Mellon University, 4400 Fifth Ave, Pittsburgh, PA, 15213, USA
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168th Street, New York, NY, 10032, USA
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39
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Butorac C, Krizova A, Derler I. Review: Structure and Activation Mechanisms of CRAC Channels. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:547-604. [PMID: 31646526 DOI: 10.1007/978-3-030-12457-1_23] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Ca2+ release activated Ca2+ (CRAC) channels represent a primary pathway for Ca2+ to enter non-excitable cells. The two key players in this process are the stromal interaction molecule (STIM), a Ca2+ sensor embedded in the membrane of the endoplasmic reticulum, and Orai, a highly Ca2+ selective ion channel located in the plasma membrane. Upon depletion of the internal Ca2+ stores, STIM is activated, oligomerizes, couples to and activates Orai. This review provides an overview of novel findings about the CRAC channel activation mechanisms, structure and gating. In addition, it highlights, among diverse STIM and Orai mutants, also the disease-related mutants and their implications.
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Affiliation(s)
- Carmen Butorac
- Institute of Biophysics, Johannes Kepler University of Linz, Linz, Austria
| | - Adéla Krizova
- Institute of Biophysics, Johannes Kepler University of Linz, Linz, Austria
| | - Isabella Derler
- Institute of Biophysics, Johannes Kepler University of Linz, Linz, Austria.
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40
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Terwilliger TC, Adams PD, Afonine PV, Sobolev OV. Cryo-EM map interpretation and protein model-building using iterative map segmentation. Protein Sci 2020; 29:87-99. [PMID: 31599033 PMCID: PMC6933853 DOI: 10.1002/pro.3740] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/30/2019] [Accepted: 10/01/2019] [Indexed: 11/17/2022]
Abstract
A procedure for building protein chains into maps produced by single-particle electron cryo-microscopy (cryo-EM) is described. The procedure is similar to the way an experienced structural biologist might analyze a map, focusing first on secondary structure elements such as helices and sheets, then varying the contour level to identify connections between these elements. Since the high density in a map typically follows the main-chain of the protein, the main-chain connection between secondary structure elements can often be identified as the unbranched path between them with the highest minimum value along the path. This chain-tracing procedure is then combined with finding side-chain positions based on the presence of density extending away from the main path of the chain, allowing generation of a Cα model. The Cα model is converted to an all-atom model and is refined against the map. We show that this procedure is as effective as other existing methods for interpretation of cryo-EM maps and that it is considerably faster and produces models with fewer chain breaks than our previous methods that were based on approaches developed for crystallographic maps.
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Affiliation(s)
- Thomas C. Terwilliger
- Los Alamos National LaboratoryLos AlamosNew Mexico
- New Mexico ConsortiumLos AlamosNew Mexico
| | - Paul D. Adams
- Molecular Biophysics & Integrated Bioimaging DivisionLawrence Berkeley National LaboratoryBerkeleyCalifornia
- Department of BioengineeringUniversity of California BerkeleyBerkeleyCalifornia
| | - Pavel V. Afonine
- Molecular Biophysics & Integrated Bioimaging DivisionLawrence Berkeley National LaboratoryBerkeleyCalifornia
| | - Oleg V. Sobolev
- Molecular Biophysics & Integrated Bioimaging DivisionLawrence Berkeley National LaboratoryBerkeleyCalifornia
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41
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Chernov-Rogan T, Gianti E, Liu C, Villemure E, Cridland AP, Hu X, Ballini E, Lange W, Deisemann H, Li T, Ward SI, Hackos DH, Magnuson S, Safina B, Klein ML, Volgraf M, Carnevale V, Chen J. TRPA1 modulation by piperidine carboxamides suggests an evolutionarily conserved binding site and gating mechanism. Proc Natl Acad Sci U S A 2019; 116:26008-26019. [PMID: 31796582 PMCID: PMC6926016 DOI: 10.1073/pnas.1913929116] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The transient receptor potential ankyrin 1 (TRPA1) channel functions as an irritant sensor and is a therapeutic target for treating pain, itch, and respiratory diseases. As a ligand-gated channel, TRPA1 can be activated by electrophilic compounds such as allyl isothiocyanate (AITC) through covalent modification or activated by noncovalent agonists through ligand binding. However, how covalent modification leads to channel opening and, importantly, how noncovalent binding activates TRPA1 are not well-understood. Here we report a class of piperidine carboxamides (PIPCs) as potent, noncovalent agonists of human TRPA1. Based on their species-specific effects on human and rat channels, we identified residues critical for channel activation; we then generated binding modes for TRPA1-PIPC interactions using structural modeling, molecular docking, and mutational analysis. We show that PIPCs bind to a hydrophobic site located at the interface of the pore helix 1 (PH1) and S5 and S6 transmembrane segments. Interestingly, this binding site overlaps with that of known allosteric modulators, such as A-967079 and propofol. Similar binding sites, involving π-helix rearrangements on S6, have been recently reported for other TRP channels, suggesting an evolutionarily conserved mechanism. Finally, we show that for PIPC analogs, predictions from computational modeling are consistent with experimental structure-activity studies, thereby suggesting strategies for rational drug design.
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Affiliation(s)
- Tania Chernov-Rogan
- Biochemical and Cellular Pharmacology, Genentech, Inc., South San Francisco, CA 94080
| | - Eleonora Gianti
- Institute for Computational Molecular Science, Department of Chemistry, Temple University, Philadelphia, PA 19122;
| | - Chang Liu
- Biochemical and Cellular Pharmacology, Genentech, Inc., South San Francisco, CA 94080
| | - Elisia Villemure
- Discovery Chemistry, Genentech, Inc., South San Francisco, CA 94080
| | | | - Xiaoyu Hu
- Biochemical and Cellular Pharmacology, Genentech, Inc., South San Francisco, CA 94080
| | - Elisa Ballini
- Ion Channel Group, Evotec AG, 22419 Hamburg, Germany
| | - Wienke Lange
- Ion Channel Group, Evotec AG, 22419 Hamburg, Germany
| | | | - Tianbo Li
- Biochemical and Cellular Pharmacology, Genentech, Inc., South San Francisco, CA 94080
| | - Stuart I Ward
- Charles River, CM19 5TR Harlow, Essex, United Kingdom
| | - David H Hackos
- Neuroscience, Genentech, Inc., South San Francisco, CA 94080
| | - Steven Magnuson
- Discovery Chemistry, Genentech, Inc., South San Francisco, CA 94080
| | - Brian Safina
- Discovery Chemistry, Genentech, Inc., South San Francisco, CA 94080
| | - Michael L Klein
- Institute for Computational Molecular Science, Department of Chemistry, Temple University, Philadelphia, PA 19122
| | - Matthew Volgraf
- Discovery Chemistry, Genentech, Inc., South San Francisco, CA 94080
| | - Vincenzo Carnevale
- Institute for Computational Molecular Science, Department of Chemistry, Temple University, Philadelphia, PA 19122;
| | - Jun Chen
- Biochemical and Cellular Pharmacology, Genentech, Inc., South San Francisco, CA 94080;
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42
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Alharbi AF, Parrington J. Endolysosomal Ca 2+ Signaling in Cancer: The Role of TPC2, From Tumorigenesis to Metastasis. Front Cell Dev Biol 2019; 7:302. [PMID: 31867325 PMCID: PMC6904370 DOI: 10.3389/fcell.2019.00302] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/08/2019] [Indexed: 12/20/2022] Open
Abstract
Ca2+ homeostasis is dysregulated in cancer cells and affects processes such as tumorigenesis, angiogenesis, autophagy, progression, and metastasis. Emerging evidence has suggested that endolysosomal cation channels sustain several cancer hallmarks involving proliferation, metastasis, and angiogenesis. Here, we investigate the role of TPC1-2, TRPML1-3, and P2×4 in cancer, with a particular focus on the role of TPC2 in cancer development, melanoma, and other cancer types as well as its endogenous and exogenous modulators. It has become evident that TPC2 plays a role in cancer; however, the precise mechanisms underlying its exact role remain elusive. TPC2 is a potential candidate for cancer biomarkers and a druggable target for future cancer therapy.
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Affiliation(s)
- Abeer F. Alharbi
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
- Department of Pharmaceutical Sciences, College of Pharmacy, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - John Parrington
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
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43
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Structural insights into group II TRP channels. Cell Calcium 2019; 86:102107. [PMID: 31841954 DOI: 10.1016/j.ceca.2019.102107] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/29/2019] [Accepted: 10/29/2019] [Indexed: 01/01/2023]
Abstract
The seven members of the TRP channel superfamily are divided into two main groups with five members comprising group I (TRPC/V/M/N/A) and TRPML (TRP MucoLipin) and TRPP (TRP Polycystin) making up group II. Group II channels share a high sequence homology on their transmembrane domains and are distinct from group I members as they contain a large luminal/extracellular domain between transmembrane helix 1 (S1) and S2. Since 2016, there are more than ten research papers reporting various structures of group II channels by either cryo-EM or X-ray crystallography. These studies along with recent functional analysis by the other groups have considerably strengthened our knowledge on TRPML and TRPP channels. In this review, we summarize and discuss these reports providing molecular insights into the group II TRP channel family.
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44
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Diver MM, Cheng Y, Julius D. Structural insights into TRPM8 inhibition and desensitization. Science 2019; 365:1434-1440. [PMID: 31488702 PMCID: PMC7262954 DOI: 10.1126/science.aax6672] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/26/2019] [Indexed: 12/27/2022]
Abstract
The transient receptor potential melastatin 8 (TRPM8) ion channel is the primary detector of environmental cold and an important target for treating pathological cold hypersensitivity. Here, we present cryo-electron microscopy structures of TRPM8 in ligand-free, antagonist-bound, or calcium-bound forms, revealing how robust conformational changes give rise to two nonconducting states, closed and desensitized. We describe a malleable ligand-binding pocket that accommodates drugs of diverse chemical structures, and we delineate the ion permeation pathway, including the contribution of lipids to pore architecture. Furthermore, we show that direct calcium binding mediates stimulus-evoked desensitization, clarifying this important mechanism of sensory adaptation. We observe large rearrangements within the S4-S5 linker that reposition the S1-S4 and pore domains relative to the TRP helix, leading us to propose a distinct model for modulation of TRPM8 and possibly other TRP channels.
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Affiliation(s)
- Melinda M Diver
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA.
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, USA
| | - David Julius
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA.
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45
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Abstract
Transient receptor potential (TRP) ion channels are molecular sensors of a large variety of stimuli including temperature, mechanical stress, voltage, small molecules including capsaicin and menthol, and lipids such as phosphatidylinositol 4,5-bisphosphate (PIP2). Since the same TRP channels may respond to different physical and chemical stimuli, they can serve as signal integrators. Many TRP channels are calcium permeable and contribute to Ca2+ homeostasis and signaling. Although the TRP channel family was discovered decades ago, only recently have the structures of many of these channels been solved, largely by cryo-electron microscopy (cryo-EM). Complimentary to cryo-EM, X-ray crystallography provides unique tools to unambiguously identify specific atoms and can be used to study ion binding in channel pores. In this review we describe crystallographic studies of the TRP channel TRPV6. The methodology used in these studies may serve as a template for future structural analyses of different types of TRP and other ion channels.
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Affiliation(s)
- Appu K Singh
- a Department of Biochemistry and Molecular Biophysics , Columbia University , New York , NY
| | - Luke L McGoldrick
- a Department of Biochemistry and Molecular Biophysics , Columbia University , New York , NY.,b Integrated Program in Cellular, Molecular and Biomedical Studies, Columbia University , New York , NY
| | - Kei Saotome
- a Department of Biochemistry and Molecular Biophysics , Columbia University , New York , NY
| | - Alexander I Sobolevsky
- a Department of Biochemistry and Molecular Biophysics , Columbia University , New York , NY
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46
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Zubcevic L, Lee SY. The role of π-helices in TRP channel gating. Curr Opin Struct Biol 2019; 58:314-323. [PMID: 31378426 DOI: 10.1016/j.sbi.2019.06.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 12/21/2022]
Abstract
Transient Receptor Potential (TRP) channels are a large superfamily of polymodal ion channels, which perform important roles in numerous physiological processes. The architecture of their transmembrane (TM) domains closely resembles that of voltage-gated potassium channels (KV). However, recent cryoEM and crystallographic studies of TRP channels have identified π-helices in functionally important regions, and it is increasingly recognized that they utilize a distinct mechanism of gating that relies on α-to-π secondary structure transitions. Here we review our current understanding of the role of π-helices in TRP channel function and their broader impact on different classes of ion channels.
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Affiliation(s)
- Lejla Zubcevic
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Seok-Yong Lee
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA.
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47
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Viet KK, Wagner A, Schwickert K, Hellwig N, Brennich M, Bader N, Schirmeister T, Morgner N, Schindelin H, Hellmich UA. Structure of the Human TRPML2 Ion Channel Extracytosolic/Lumenal Domain. Structure 2019; 27:1246-1257.e5. [DOI: 10.1016/j.str.2019.04.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 04/16/2019] [Accepted: 04/29/2019] [Indexed: 11/28/2022]
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48
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Krogsaeter EK, Biel M, Wahl-Schott C, Grimm C. The protein interaction networks of mucolipins and two-pore channels. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2019; 1866:1111-1123. [PMID: 30395881 PMCID: PMC7111325 DOI: 10.1016/j.bbamcr.2018.10.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/24/2018] [Accepted: 10/26/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND The endolysosomal, non-selective cation channels, two-pore channels (TPCs) and mucolipins (TRPMLs), regulate intracellular membrane dynamics and autophagy. While partially compensatory for each other, isoform-specific intracellular distribution, cell-type expression patterns, and regulatory mechanisms suggest different channel isoforms confer distinct properties to the cell. SCOPE OF REVIEW Briefly, established TPC/TRPML functions and interaction partners ('interactomes') are discussed. Novel TRPML3 interactors are shown, and a meta-analysis of experimentally obtained channel interactomes conducted. Accordingly, interactomes are compared and contrasted, and subsequently described in detail for TPC1, TPC2, TRPML1, and TRPML3. MAJOR CONCLUSIONS TPC interactomes are well-defined, encompassing intracellular membrane organisation proteins. TRPML interactomes are varied, encompassing cardiac contractility- and chaperone-mediated autophagy proteins, alongside regulators of intercellular signalling. GENERAL SIGNIFICANCE Comprising recently proposed targets to treat cancers, infections, metabolic disease and neurodegeneration, the advancement of TPC/TRPML understanding is of considerable importance. This review proposes novel directions elucidating TPC/TRPML relevance in health and disease. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.
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Affiliation(s)
- Einar K Krogsaeter
- Department of Pharmacology and Toxicology, Faculty of Medicine, University of Munich (LMU) Nussbaumstrasse 26, 80336 Munich
| | - Martin Biel
- Department of Pharmacy - Center for Drug Research and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität München, Germany
| | - Christian Wahl-Schott
- Hannover Medical School, Institute for Neurophysiology, OE 4230, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Christian Grimm
- Department of Pharmacology and Toxicology, Faculty of Medicine, University of Munich (LMU) Nussbaumstrasse 26, 80336 Munich.
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49
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Vangeel L, Voets T. Transient Receptor Potential Channels and Calcium Signaling. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a035048. [PMID: 30910771 DOI: 10.1101/cshperspect.a035048] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Transient receptor potential (TRP) cation channels play diverse roles in cellular Ca2+ signaling. First, as Ca2+-permeable channels that respond to a variety of stimuli, TRP channels can directly initiate cellular Ca2+ signals. Second, as nonselective cation channels, TRP channel activation leads to membrane depolarization, influencing Ca2+ influx via voltage-gated and store-operated Ca2+ channels. Finally, Ca2+ modulates the activity of most TRP channels, allowing them to function as molecular effectors downstream of intracellular Ca2+ signals. Whereas the TRP channel field has long been devoid of detailed channel structures, recent advances, particularly in cryo-electron microscopy-based structural approaches, have yielded a flurry of TRP channel structures, including members from all seven subfamilies. These structures, in conjunction with mutagenesis-based functional approaches, provided important new insights into the mechanisms whereby TRP channels permeate and sense Ca2+ These insights will be highly instrumental in the rational design of novel treatments for the multitude of TRP channel-related diseases.
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Affiliation(s)
- Laura Vangeel
- Laboratory of Ion Channel Research, VIB Center for Brain and Disease Research & Department of Cellular and Molecular Medicine, University of Leuven, B-3000 Leuven, Belgium
| | - Thomas Voets
- Laboratory of Ion Channel Research, VIB Center for Brain and Disease Research & Department of Cellular and Molecular Medicine, University of Leuven, B-3000 Leuven, Belgium
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50
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Zhang X, Chen W, Gao Q, Yang J, Yan X, Zhao H, Su L, Yang M, Gao C, Yao Y, Inoki K, Li D, Shao R, Wang S, Sahoo N, Kudo F, Eguchi T, Ruan B, Xu H. Rapamycin directly activates lysosomal mucolipin TRP channels independent of mTOR. PLoS Biol 2019; 17:e3000252. [PMID: 31112550 PMCID: PMC6528971 DOI: 10.1371/journal.pbio.3000252] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 04/18/2019] [Indexed: 02/06/2023] Open
Abstract
Rapamycin (Rap) and its derivatives, called rapalogs, are being explored in clinical trials targeting cancer and neurodegeneration. The underlying mechanisms of Rap actions, however, are not well understood. Mechanistic target of rapamycin (mTOR), a lysosome-localized protein kinase that acts as a critical regulator of cellular growth, is believed to mediate most Rap actions. Here, we identified mucolipin 1 (transient receptor potential channel mucolipin 1 [TRPML1], also known as MCOLN1), the principle Ca2+ release channel in the lysosome, as another direct target of Rap. Patch-clamping of isolated lysosomal membranes showed that micromolar concentrations of Rap and some rapalogs activated lysosomal TRPML1 directly and specifically. Pharmacological inhibition or genetic inactivation of mTOR failed to mimic the Rap effect. In vitro binding assays revealed that Rap bound directly to purified TRPML1 proteins with a micromolar affinity. In both healthy and disease human fibroblasts, Rap and rapalogs induced autophagic flux via nuclear translocation of transcription factor EB (TFEB). However, such effects were abolished in TRPML1-deficient cells or by TRPML1 inhibitors. Hence, Rap and rapalogs promote autophagy via a TRPML1-dependent mechanism. Given the demonstrated roles of TRPML1 and TFEB in cellular clearance, we propose that lysosomal TRPML1 may contribute a significant portion to the in vivo neuroprotective and anti-aging effects of Rap via an augmentation of autophagy and lysosomal biogenesis.
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Affiliation(s)
- Xiaoli Zhang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Wei Chen
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Qiong Gao
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Junsheng Yang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| | - Xueni Yan
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| | - Han Zhao
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| | - Lin Su
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| | - Meimei Yang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Neurology, The Fourth Hospital of Harbin Medical University, Harbin, China
| | - Chenlang Gao
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Yao Yao
- Department of Integrative and Molecular Physiology and Internal Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Ken Inoki
- Department of Integrative and Molecular Physiology and Internal Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Dan Li
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| | - Rong Shao
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| | - Shiyi Wang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Nirakar Sahoo
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Fumitaka Kudo
- Department of Chemistry, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, Japan
| | - Tadashi Eguchi
- Department of Chemistry, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, Japan
| | - Benfang Ruan
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
- * E-mail: (HX); (BR)
| | - Haoxing Xu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (HX); (BR)
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