1
|
Fairweather SJ, Shah N, Brӧer S. Heteromeric Solute Carriers: Function, Structure, Pathology and Pharmacology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 21:13-127. [PMID: 33052588 DOI: 10.1007/5584_2020_584] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Solute carriers form one of three major superfamilies of membrane transporters in humans, and include uniporters, exchangers and symporters. Following several decades of molecular characterisation, multiple solute carriers that form obligatory heteromers with unrelated subunits are emerging as a distinctive principle of membrane transporter assembly. Here we comprehensively review experimentally established heteromeric solute carriers: SLC3-SLC7 amino acid exchangers, SLC16 monocarboxylate/H+ symporters and basigin/embigin, SLC4A1 (AE1) and glycophorin A exchanger, SLC51 heteromer Ost α-Ost β uniporter, and SLC6 heteromeric symporters. The review covers the history of the heteromer discovery, transporter physiology, structure, disease associations and pharmacology - all with a focus on the heteromeric assembly. The cellular locations, requirements for complex formation, and the functional role of dimerization are extensively detailed, including analysis of the first complete heteromer structures, the SLC7-SLC3 family transporters LAT1-4F2hc, b0,+AT-rBAT and the SLC6 family heteromer B0AT1-ACE2. We present a systematic analysis of the structural and functional aspects of heteromeric solute carriers and conclude with common principles of their functional roles and structural architecture.
Collapse
Affiliation(s)
- Stephen J Fairweather
- Research School of Biology, Australian National University, Canberra, ACT, Australia. .,Resarch School of Chemistry, Australian National University, Canberra, ACT, Australia.
| | - Nishank Shah
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Stefan Brӧer
- Research School of Biology, Australian National University, Canberra, ACT, Australia.
| |
Collapse
|
2
|
TASK channels: channelopathies, trafficking, and receptor-mediated inhibition. Pflugers Arch 2020; 472:911-922. [DOI: 10.1007/s00424-020-02403-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/08/2020] [Accepted: 05/18/2020] [Indexed: 01/06/2023]
|
3
|
Capera J, Serrano-Novillo C, Navarro-Pérez M, Cassinelli S, Felipe A. The Potassium Channel Odyssey: Mechanisms of Traffic and Membrane Arrangement. Int J Mol Sci 2019; 20:ijms20030734. [PMID: 30744118 PMCID: PMC6386995 DOI: 10.3390/ijms20030734] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/06/2019] [Accepted: 02/08/2019] [Indexed: 12/29/2022] Open
Abstract
Ion channels are transmembrane proteins that conduct specific ions across biological membranes. Ion channels are present at the onset of many cellular processes, and their malfunction triggers severe pathologies. Potassium channels (KChs) share a highly conserved signature that is necessary to conduct K⁺ through the pore region. To be functional, KChs require an exquisite regulation of their subcellular location and abundance. A wide repertoire of signatures facilitates the proper targeting of the channel, fine-tuning the balance that determines traffic and location. These signature motifs can be part of the secondary or tertiary structure of the protein and are spread throughout the entire sequence. Furthermore, the association of the pore-forming subunits with different ancillary proteins forms functional complexes. These partners can modulate traffic and activity by adding their own signatures as well as by exposing or masking the existing ones. Post-translational modifications (PTMs) add a further dimension to traffic regulation. Therefore, the fate of a KCh is not fully dependent on a gene sequence but on the balance of many other factors regulating traffic. In this review, we assemble recent evidence contributing to our understanding of the spatial expression of KChs in mammalian cells. We compile specific signatures, PTMs, and associations that govern the destination of a functional channel.
Collapse
Affiliation(s)
- Jesusa Capera
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Avda. Diagonal 643, 08028 Barcelona, Spain.
| | - Clara Serrano-Novillo
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Avda. Diagonal 643, 08028 Barcelona, Spain.
| | - María Navarro-Pérez
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Avda. Diagonal 643, 08028 Barcelona, Spain.
| | - Silvia Cassinelli
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Avda. Diagonal 643, 08028 Barcelona, Spain.
| | - Antonio Felipe
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Avda. Diagonal 643, 08028 Barcelona, Spain.
| |
Collapse
|
4
|
Gigante A, Grad JN, Briels J, Bartel M, Hoffmann D, Ottmann C, Schmuck C. A new class of supramolecular ligands stabilizes 14-3-3 protein-protein interactions by up to two orders of magnitude. Chem Commun (Camb) 2019; 55:111-114. [PMID: 30515494 DOI: 10.1039/c8cc07946c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We report the first supramolecular stabilizers of the interaction between 14-3-3ζ and two of its effectors, Tau and C-Raf, which are involved in neurodegenerative diseases and proliferative signal transduction, respectively. These supramolecular ligands open up an opportunity to modulate functions of 14-3-3 with these effectors.
Collapse
Affiliation(s)
- A Gigante
- Institute of Organic Chemistry, University of Duisburg Essen, Universitätstr. 7, 45141, Essen, Germany.
| | | | | | | | | | | | | |
Collapse
|
5
|
Leanza L, Checchetto V, Biasutto L, Rossa A, Costa R, Bachmann M, Zoratti M, Szabo I. Pharmacological modulation of mitochondrial ion channels. Br J Pharmacol 2019; 176:4258-4283. [PMID: 30440086 DOI: 10.1111/bph.14544] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 10/15/2018] [Accepted: 10/22/2018] [Indexed: 12/17/2022] Open
Abstract
The field of mitochondrial ion channels has undergone a rapid development during the last three decades, due to the molecular identification of some of the channels residing in the outer and inner membranes. Relevant information about the function of these channels in physiological and pathological settings was gained thanks to genetic models for a few, mitochondria-specific channels. However, many ion channels have multiple localizations within the cell, hampering a clear-cut determination of their function by pharmacological means. The present review summarizes our current knowledge about the ins and outs of mitochondrial ion channels, with special focus on the channels that have received much attention in recent years, namely, the voltage-dependent anion channels, the permeability transition pore (also called mitochondrial megachannel), the mitochondrial calcium uniporter and some of the inner membrane-located potassium channels. In addition, possible strategies to overcome the difficulties of specifically targeting mitochondrial channels versus their counterparts active in other membranes are discussed, as well as the possibilities of modulating channel function by small peptides that compete for binding with protein interacting partners. Altogether, these promising tools along with large-scale chemical screenings set up to identify new, specific channel modulators will hopefully allow us to pinpoint the actual function of most mitochondrial ion channels in the near future and to pharmacologically affect important pathologies in which they are involved, such as neurodegeneration, ischaemic damage and cancer. LINKED ARTICLES: This article is part of a themed section on Mitochondrial Pharmacology: Featured Mechanisms and Approaches for Therapy Translation. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.22/issuetoc.
Collapse
Affiliation(s)
- Luigi Leanza
- Department of Biology, University of Padova, Padova, Italy
| | | | - Lucia Biasutto
- CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Andrea Rossa
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Roberto Costa
- Department of Biology, University of Padova, Padova, Italy
| | | | - Mario Zoratti
- CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ildiko Szabo
- Department of Biology, University of Padova, Padova, Italy.,CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
| |
Collapse
|
6
|
Inoue M, Matsuoka H, Lesage F, Harada K. Lack of p11 expression facilitates acidity‐sensing function of TASK1 channels in mouse adrenal medullary cells. FASEB J 2018; 33:455-468. [DOI: 10.1096/fj.201800407rr] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Masumi Inoue
- Department of Cell and Systems PhysiologySchool of MedicineUniversity of Occupational and Environmental Health Kitakyushu Japan
| | - Hidetada Matsuoka
- Department of Cell and Systems PhysiologySchool of MedicineUniversity of Occupational and Environmental Health Kitakyushu Japan
| | - Florian Lesage
- Université Côte d'AzurINSERMCentre National de la Recherche Scientifique (CNRS)Institut de Pharmacologie Moléculaire et CellulaireLaboratory of Excellence in Ion Channel Science and Therapeutics (LabEx ICST) Valbonne France
| | - Keita Harada
- Department of Cell and Systems PhysiologySchool of MedicineUniversity of Occupational and Environmental Health Kitakyushu Japan
| |
Collapse
|
7
|
Vierra NC, Dadi PK, Milian SC, Dickerson MT, Jordan KL, Gilon P, Jacobson DA. TALK-1 channels control β cell endoplasmic reticulum Ca 2+ homeostasis. Sci Signal 2017; 10:eaan2883. [PMID: 28928238 PMCID: PMC5672804 DOI: 10.1126/scisignal.aan2883] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Ca2+ handling by the endoplasmic reticulum (ER) serves critical roles in controlling pancreatic β cell function and becomes perturbed during the pathogenesis of diabetes. ER Ca2+ homeostasis is determined by ion movements across the ER membrane, including K+ flux through K+ channels. We demonstrated that K+ flux through ER-localized TALK-1 channels facilitated Ca2+ release from the ER in mouse and human β cells. We found that β cells from mice lacking TALK-1 exhibited reduced basal cytosolic Ca2+ and increased ER Ca2+ concentrations, suggesting reduced ER Ca2+ leak. These changes in Ca2+ homeostasis were presumably due to TALK-1-mediated ER K+ flux, because we recorded K+ currents mediated by functional TALK-1 channels on the nuclear membrane, which is continuous with the ER. Moreover, overexpression of K+-impermeable TALK-1 channels in HEK293 cells did not reduce ER Ca2+ stores. Reduced ER Ca2+ content in β cells is associated with ER stress and islet dysfunction in diabetes, and islets from TALK-1-deficient mice fed a high-fat diet showed reduced signs of ER stress, suggesting that TALK-1 activity exacerbated ER stress. Our data establish TALK-1 channels as key regulators of β cell ER Ca2+ and suggest that TALK-1 may be a therapeutic target to reduce ER Ca2+ handling defects in β cells during the pathogenesis of diabetes.
Collapse
Affiliation(s)
- Nicholas C Vierra
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Prasanna K Dadi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Sarah C Milian
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Matthew T Dickerson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Kelli L Jordan
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Patrick Gilon
- Pôle d'endocrinologie, diabète et nutrition, Institut de recherche expérimentale et clinique, Université catholique de Louvain, Brussels 1200, Belgium
| | - David A Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA.
| |
Collapse
|
8
|
Leist M, Rinné S, Datunashvili M, Aissaoui A, Pape HC, Decher N, Meuth SG, Budde T. Acetylcholine-dependent upregulation of TASK-1 channels in thalamic interneurons by a smooth muscle-like signalling pathway. J Physiol 2017; 595:5875-5893. [PMID: 28714121 DOI: 10.1113/jp274527] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/10/2017] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS The ascending brainstem transmitter acetylcholine depolarizes thalamocortical relay neurons while it induces hyperpolarization in local circuit inhibitory interneurons. Sustained K+ currents are modulated in thalamic neurons to control their activity modes; for the interneurons the molecular nature of the underlying ion channels is as yet unknown. Activation of TASK-1 K+ channels results in hyperpolarization of interneurons and suppression of their action potential firing. The modulation cascade involves a non-receptor tyrosine kinase, c-Src. The present study identifies a novel pathway for the activation of TASK-1 channels in CNS neurons that resembles cholinergic signalling and TASK-1 current modulation during hypoxia in smooth muscle cells. ABSTRACT The dorsal part of the lateral geniculate nucleus (dLGN) is the main thalamic site for state-dependent transmission of visual information. Non-retinal inputs from the ascending arousal system and inhibition provided by γ-aminobutyric acid (GABA)ergic local circuit interneurons (INs) control neuronal activity within the dLGN. In particular, acetylcholine (ACh) depolarizes thalamocortical relay neurons by inhibiting two-pore domain potassium (K2P ) channels. Conversely, ACh also hyperpolarizes INs via an as-yet-unknown mechanism. By using whole cell patch-clamp recordings in brain slices and appropriate pharmacological tools we here report that stimulation of type 2 muscarinic ACh receptors induces IN hyperpolarization by recruiting the G-protein βγ subunit (Gβγ), class-1A phosphatidylinositol-4,5-bisphosphate 3-kinase, and cellular and sarcoma (c-Src) tyrosine kinase, leading to activation of two-pore domain weakly inwardly rectifying K+ channel (TWIK)-related acid-sensitive K+ (TASK)-1 channels. The latter was confirmed by the use of TASK-1-deficient mice. Furthermore inhibition of phospholipase Cβ as well as an increase in the intracellular level of phosphatidylinositol-3,4,5-trisphosphate facilitated the muscarinic effect. Our results have uncovered a previously unknown role of c-Src tyrosine kinase in regulating IN function in the brain and identified a novel mechanism by which TASK-1 channels are activated in neurons.
Collapse
Affiliation(s)
- Michael Leist
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Susanne Rinné
- Institut für Physiologie und Pathophysiologie, AG Vegetative Physiologie, Philipps-Universität, Deutschhausstraße 1-2, D-35037, Marburg, Germany
| | - Maia Datunashvili
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Ania Aissaoui
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Hans-Christian Pape
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Niels Decher
- Institut für Physiologie und Pathophysiologie, AG Vegetative Physiologie, Philipps-Universität, Deutschhausstraße 1-2, D-35037, Marburg, Germany
| | - Sven G Meuth
- Department of Neurology, Westfälische Wilhelms-Universität, Albert-Schweitzer-Campus 1, D-48149, Münster, Germany
| | - Thomas Budde
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| |
Collapse
|
9
|
Xiao Y, Dai Q, Hu R, Pacheco S, Yang Y, Liang G, Soberón M, Bravo A, Liu K, Wu K. A Single Point Mutation Resulting in Cadherin Mislocalization Underpins Resistance against Bacillus thuringiensis Toxin in Cotton Bollworm. J Biol Chem 2017; 292:2933-2943. [PMID: 28082675 DOI: 10.1074/jbc.m116.768671] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 01/10/2017] [Indexed: 01/01/2023] Open
Abstract
Transgenic plants that produce Bacillus thuringiensis (Bt) crystalline (Cry) toxins are cultivated worldwide to control insect pests. Resistance to B. thuringiensis toxins threatens this technology, and although different resistance mechanisms have been identified, some have not been completely elucidated. To gain new insights into these mechanisms, we performed multiple back-crossing from a 3000-fold Cry1Ac-resistant BtR strain from cotton bollworm (Helicoverpa armigera), isolating a 516-fold Cry1Ac-resistant strain (96CAD). Cry1Ac resistance in 96CAD was tightly linked to a mutant cadherin allele (mHaCad) that contained 35 amino acid substitutions compared with HaCad from a susceptible strain (96S). We observed significantly reduced levels of the mHaCad protein on the surface of the midgut epithelium in 96CAD as compared with 96S. Expression of both cadherin alleles from 96CAD and 96S in insect cells and immunofluorescence localization in insect midgut tissue sections showed that the HaCAD protein from 96S localizes on the cell membrane, whereas the mutant 96CAD-mHaCad was retained in the endoplasmic reticulum (ER). Mapping of the mutations identified a D172G substitution mainly responsible for cadherin mislocalization. Our finding of a mutation affecting membrane receptor trafficking represents an unusual and previously unrecognized B. thuringiensis resistance mechanism.
Collapse
Affiliation(s)
- Yutao Xiao
- From the State Key Laboratory for Biology of Plant Disease and Insect Pests, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, China.,the Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Qing Dai
- the College of Life Science, Central China Normal University, No. 152 Luoyu Avenue, Wuhan 430079, China, and
| | - Ruqin Hu
- From the State Key Laboratory for Biology of Plant Disease and Insect Pests, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, China.,the College of Life Science, Central China Normal University, No. 152 Luoyu Avenue, Wuhan 430079, China, and
| | - Sabino Pacheco
- the Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | - Yongbo Yang
- the College of Life Science, Central China Normal University, No. 152 Luoyu Avenue, Wuhan 430079, China, and
| | - Gemei Liang
- From the State Key Laboratory for Biology of Plant Disease and Insect Pests, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, China
| | - Mario Soberón
- the Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | - Alejandra Bravo
- the Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | - Kaiyu Liu
- the College of Life Science, Central China Normal University, No. 152 Luoyu Avenue, Wuhan 430079, China, and
| | - Kongming Wu
- From the State Key Laboratory for Biology of Plant Disease and Insect Pests, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, China,
| |
Collapse
|
10
|
Taguchi YH. Principal component analysis based unsupervised feature extraction applied to publicly available gene expression profiles provides new insights into the mechanisms of action of histone deacetylase inhibitors. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.nepig.2016.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
11
|
Chen YD, Fang YT, Chang CP, Lin CF, Hsu LJ, Wu SR, Chiu YC, Anderson R, Lin YS. S100A10 Regulates ULK1 Localization to ER-Mitochondria Contact Sites in IFN-γ-Triggered Autophagy. J Mol Biol 2016; 429:142-157. [PMID: 27871932 DOI: 10.1016/j.jmb.2016.11.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 10/28/2016] [Accepted: 11/15/2016] [Indexed: 01/07/2023]
Abstract
During the process of autophagy, the autophagy-related proteins are translocated to autophagosome formation sites. Here, we demonstrate that S100A10 is required for ULK1 localization to autophagosome formation sites. Silencing of S100A10 reduces IFN-γ-induced autophagosome formation. We also determined the role of annexin A2 (ANXA2), a binding partner of S100A10, which has been reported to promote phagophore assembly. Silencing of ANXA2 reduced S100A10 expression. However, overexpression of S100A10 in ANXA2-silenced cells was still able to enhance autophagosome formation, suggesting that ANXA2 regulates IFN-γ-induced autophagy through S100A10. We also observed that S100A10 interacted with ULK1 after IFN-γ stimulation, and S100A10 knockdown prevented ULK1 localization to autophagosome formation sites. Finally, the release of high mobility group protein B1, one of the functions mediated by IFN-γ-induced autophagy, was inhibited in S100A10 knockdown cells. These results elucidate the importance of S100A10 in autophagosome formation and reveal the relationship between S100A10 and ULK1 in IFN-γ-induced autophagy.
Collapse
Affiliation(s)
- Ying-Da Chen
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Yi-Ting Fang
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Chih-Peng Chang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Chiou-Feng Lin
- Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; Department of Microbiology and Immunology, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
| | - Li-Jin Hsu
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Shang-Rung Wu
- Institute of Oral Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Yen-Chi Chiu
- Institute of Oral Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Robert Anderson
- Departments of Microbiology & Immunology and Pediatrics, and Canadian Center for Vaccinology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Yee-Shin Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan.
| |
Collapse
|
12
|
TASK-1 Regulates Apoptosis and Proliferation in a Subset of Non-Small Cell Lung Cancers. PLoS One 2016; 11:e0157453. [PMID: 27294516 PMCID: PMC4905626 DOI: 10.1371/journal.pone.0157453] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 05/31/2016] [Indexed: 12/29/2022] Open
Abstract
Lung cancer is the leading cause of cancer deaths worldwide; survival times are poor despite therapy. The role of the two-pore domain K+ (K2P) channel TASK-1 (KCNK3) in lung cancer is at present unknown. We found that TASK-1 is expressed in non-small cell lung cancer (NSCLC) cell lines at variable levels. In a highly TASK-1 expressing NSCLC cell line, A549, a characteristic pH- and hypoxia-sensitive non-inactivating K+ current was measured, indicating the presence of functional TASK-1 channels. Inhibition of TASK-1 led to significant depolarization in these cells. Knockdown of TASK-1 by siRNA significantly enhanced apoptosis and reduced proliferation in A549 cells, but not in weakly TASK-1 expressing NCI-H358 cells. Na+-coupled nutrient transport across the cell membrane is functionally coupled to the efflux of K+ via K+ channels, thus TASK-1 may potentially influence Na+-coupled nutrient transport. In contrast to TASK-1, which was not differentially expressed in lung cancer vs. normal lung tissue, we found the Na+-coupled nutrient transporters, SLC5A3, SLC5A6, and SLC38A1, transporters for myo-inositol, biotin and glutamine, respectively, to be significantly overexpressed in lung adenocarcinomas. In summary, we show for the first time that the TASK-1 channel regulates apoptosis and proliferation in a subset of NSCLC.
Collapse
|
13
|
Characterization and small-molecule stabilization of the multisite tandem binding between 14-3-3 and the R domain of CFTR. Proc Natl Acad Sci U S A 2016; 113:E1152-61. [PMID: 26888287 DOI: 10.1073/pnas.1516631113] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Cystic fibrosis is a fatal genetic disease, most frequently caused by the retention of the CFTR (cystic fibrosis transmembrane conductance regulator) mutant protein in the endoplasmic reticulum (ER). The binding of the 14-3-3 protein to the CFTR regulatory (R) domain has been found to enhance CFTR trafficking to the plasma membrane. To define the mechanism of action of this protein-protein interaction, we have examined the interaction in vitro. The disordered multiphosphorylated R domain contains nine different 14-3-3 binding motifs. Furthermore, the 14-3-3 protein forms a dimer containing two amphipathic grooves that can potentially bind these phosphorylated motifs. This results in a number of possible binding mechanisms between these two proteins. Using multiple biochemical assays and crystal structures, we show that the interaction between them is governed by two binding sites: The key binding site of CFTR (pS768) occupies one groove of the 14-3-3 dimer, and a weaker, secondary binding site occupies the other binding groove. We show that fusicoccin-A, a natural-product tool compound used in studies of 14-3-3 biology, can stabilize the interaction between 14-3-3 and CFTR by selectively interacting with a secondary binding motif of CFTR (pS753). The stabilization of this interaction stimulates the trafficking of mutant CFTR to the plasma membrane. This definition of the druggability of the 14-3-3-CFTR interface might offer an approach for cystic fibrosis therapeutics.
Collapse
|
14
|
Ohya S, Kito H, Hatano N, Muraki K. Recent advances in therapeutic strategies that focus on the regulation of ion channel expression. Pharmacol Ther 2016; 160:11-43. [PMID: 26896566 DOI: 10.1016/j.pharmthera.2016.02.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A number of different ion channel types are involved in cell signaling networks, and homeostatic regulatory mechanisms contribute to the control of ion channel expression. Profiling of global gene expression using microarray technology has recently provided novel insights into the molecular mechanisms underlying the homeostatic and pathological control of ion channel expression. It has demonstrated that the dysregulation of ion channel expression is associated with the pathogenesis of neural, cardiovascular, and immune diseases as well as cancers. In addition to the transcriptional, translational, and post-translational regulation of ion channels, potentially important evidence on the mechanisms controlling ion channel expression has recently been accumulated. The regulation of alternative pre-mRNA splicing is therefore a novel therapeutic strategy for the treatment of dominant-negative splicing disorders. Epigenetic modification plays a key role in various pathological conditions through the regulation of pluripotency genes. Inhibitors of pre-mRNA splicing and histone deacetyalase/methyltransferase have potential as potent therapeutic drugs for cancers and autoimmune and inflammatory diseases. Moreover, membrane-anchoring proteins, lysosomal and proteasomal degradation-related molecules, auxiliary subunits, and pharmacological agents alter the protein folding, membrane trafficking, and post-translational modifications of ion channels, and are linked to expression-defect channelopathies. In this review, we focused on recent insights into the transcriptional, spliceosomal, epigenetic, and proteasomal regulation of ion channel expression: Ca(2+) channels (TRPC/TRPV/TRPM/TRPA/Orai), K(+) channels (voltage-gated, KV/Ca(2+)-activated, KCa/two-pore domain, K2P/inward-rectifier, Kir), and Ca(2+)-activated Cl(-) channels (TMEM16A/TMEM16B). Furthermore, this review highlights expression of these ion channels in expression-defect channelopathies.
Collapse
Affiliation(s)
- Susumu Ohya
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Hiroaki Kito
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Noriyuki Hatano
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan
| | - Katsuhiko Muraki
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan.
| |
Collapse
|
15
|
Kilisch M, Lytovchenko O, Arakel EC, Bertinetti D, Schwappach B. A dual phosphorylation switch controls 14-3-3-dependent cell surface expression of TASK-1. J Cell Sci 2016; 129:831-42. [PMID: 26743085 PMCID: PMC4760375 DOI: 10.1242/jcs.180182] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 12/29/2015] [Indexed: 11/20/2022] Open
Abstract
The transport of the K+ channels TASK-1 and TASK-3 (also known as KCNK3 and KCNK9, respectively) to the cell surface is controlled by the binding of 14-3-3 proteins to a trafficking control region at the extreme C-terminus of the channels. The current model proposes that phosphorylation-dependent binding of 14-3-3 sterically masks a COPI-binding motif. However, the direct effects of phosphorylation on COPI binding and on the binding parameters of 14-3-3 isoforms are still unknown. We find that phosphorylation of the trafficking control region prevents COPI binding even in the absence of 14-3-3, and we present a quantitative analysis of the binding of all human 14-3-3 isoforms to the trafficking control regions of TASK-1 and TASK-3. Surprisingly, the affinities of 14-3-3 proteins for TASK-1 are two orders of magnitude lower than for TASK-3. Furthermore, we find that phosphorylation of a second serine residue in the C-terminus of TASK-1 inhibits 14-3-3 binding. Thus, phosphorylation of the trafficking control region can stimulate or inhibit transport of TASK-1 to the cell surface depending on the target serine residue. Our findings indicate that control of TASK-1 trafficking by COPI, kinases, phosphatases and 14-3-3 proteins is highly dynamic. Summary: Phosphorylation of a previously neglected serine residue in the trafficking control region of TASK-1 interferes with the binding of trafficking machinery and enables complex regulation by physiological stimuli.
Collapse
Affiliation(s)
- Markus Kilisch
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, Göttingen 37073, Germany
| | - Olga Lytovchenko
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, Göttingen 37073, Germany
| | - Eric C Arakel
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, Göttingen 37073, Germany
| | | | - Blanche Schwappach
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, Göttingen 37073, Germany Max-Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| |
Collapse
|
16
|
Renigunta V, Schlichthörl G, Daut J. Much more than a leak: structure and function of K₂p-channels. Pflugers Arch 2015; 467:867-94. [PMID: 25791628 DOI: 10.1007/s00424-015-1703-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 03/09/2015] [Indexed: 11/27/2022]
Abstract
Over the last decade, we have seen an enormous increase in the number of experimental studies on two-pore-domain potassium channels (K2P-channels). The collection of reviews and original articles compiled for this special issue of Pflügers Archiv aims to give an up-to-date summary of what is known about the physiology and pathophysiology of K2P-channels. This introductory overview briefly describes the structure of K2P-channels and their function in different organs. Its main aim is to provide some background information for the 19 reviews and original articles of this special issue of Pflügers Archiv. It is not intended to be a comprehensive review; instead, this introductory overview focuses on some unresolved questions and controversial issues, such as: Do K2P-channels display voltage-dependent gating? Do K2P-channels contribute to the generation of action potentials? What is the functional role of alternative translation initiation? Do K2P-channels have one or two or more gates? We come to the conclusion that we are just beginning to understand the extremely complex regulation of these fascinating channels, which are often inadequately described as 'leak channels'.
Collapse
Affiliation(s)
- Vijay Renigunta
- Institute of Physiology and Pathophysiology, Marburg University, 35037, Marburg, Germany
| | | | | |
Collapse
|