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Schlessinger A, Zatorski N, Hutchinson K, Colas C. Targeting SLC transporters: small molecules as modulators and therapeutic opportunities. Trends Biochem Sci 2023; 48:801-814. [PMID: 37355450 PMCID: PMC10525040 DOI: 10.1016/j.tibs.2023.05.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 06/26/2023]
Abstract
Solute carrier (SLCs) transporters mediate the transport of a broad range of solutes across biological membranes. Dysregulation of SLCs has been associated with various pathologies, including metabolic and neurological disorders, as well as cancer and rare diseases. SLCs are therefore emerging as key targets for therapeutic intervention with several recently approved drugs targeting these proteins. Unlocking this large and complex group of proteins is essential to identifying unknown SLC targets and developing next-generation SLC therapeutics. Recent progress in experimental and computational techniques has significantly advanced SLC research, including drug discovery. Here, we review emerging topics in therapeutic discovery of SLCs, focusing on state-of-the-art approaches in structural, chemical, and computational biology, and discuss current challenges in transporter drug discovery.
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Affiliation(s)
- Avner Schlessinger
- Department of Pharmacological Sciences Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Nicole Zatorski
- Department of Pharmacological Sciences Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Keino Hutchinson
- Department of Pharmacological Sciences Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Claire Colas
- University of Vienna, Department of Pharmaceutical Chemistry, Vienna, Austria.
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2
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Lycas MD, Ejdrup AL, Sørensen AT, Haahr NO, Jørgensen SH, Guthrie DA, Støier JF, Werner C, Newman AH, Sauer M, Herborg F, Gether U. Nanoscopic dopamine transporter distribution and conformation are inversely regulated by excitatory drive and D2 autoreceptor activity. Cell Rep 2022; 40:111431. [PMID: 36170827 PMCID: PMC9617621 DOI: 10.1016/j.celrep.2022.111431] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 07/22/2022] [Accepted: 09/08/2022] [Indexed: 11/30/2022] Open
Abstract
The nanoscopic organization and regulation of individual molecular components in presynaptic varicosities of neurons releasing modulatory volume neurotransmitters like dopamine (DA) remain largely elusive. Here we show, by application of several super-resolution microscopy techniques to cultured neurons and mouse striatal slices, that the DA transporter (DAT), a key protein in varicosities of dopaminergic neurons, exists in the membrane in dynamic equilibrium between an inward-facing nanodomain-localized and outward-facing unclustered configuration. The balance between these configurations is inversely regulated by excitatory drive and DA D2 autoreceptor activation in a manner dependent on Ca2+ influx via N-type voltage-gated Ca2+ channels. The DAT nanodomains contain tens of transporters molecules and overlap with nanodomains of PIP2 (phosphatidylinositol-4,5-bisphosphate) but show little overlap with D2 autoreceptor, syntaxin-1, and clathrin nanodomains. The data reveal a mechanism for rapid alterations of nanoscopic DAT distribution and show a striking link of this to the conformational state of the transporter.
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Affiliation(s)
- Matthew D Lycas
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Maersk Tower 7.5, 2200 Copenhagen, Denmark
| | - Aske L Ejdrup
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Maersk Tower 7.5, 2200 Copenhagen, Denmark
| | - Andreas T Sørensen
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Maersk Tower 7.5, 2200 Copenhagen, Denmark
| | - Nicolai O Haahr
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Maersk Tower 7.5, 2200 Copenhagen, Denmark
| | - Søren H Jørgensen
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Maersk Tower 7.5, 2200 Copenhagen, Denmark
| | - Daryl A Guthrie
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Jonatan F Støier
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Maersk Tower 7.5, 2200 Copenhagen, Denmark
| | - Christian Werner
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Amy Hauck Newman
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Freja Herborg
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Maersk Tower 7.5, 2200 Copenhagen, Denmark
| | - Ulrik Gether
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Maersk Tower 7.5, 2200 Copenhagen, Denmark.
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3
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Mackie PM, Gopinath A, Montas DM, Nielsen A, Smith A, Nolan RA, Runner K, Matt SM, McNamee J, Riklan JE, Adachi K, Doty A, Ramirez-Zamora A, Yan L, Gaskill PJ, Streit WJ, Okun MS, Khoshbouei H. Functional characterization of the biogenic amine transporters on human macrophages. JCI Insight 2022; 7:151892. [PMID: 35015729 PMCID: PMC8876465 DOI: 10.1172/jci.insight.151892] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 01/05/2022] [Indexed: 11/17/2022] Open
Abstract
Monocyte-derived macrophages are key players in tissue homeostasis and diseases regulated by a variety of signaling molecules. Recent literature has highlighted the ability for biogenic amines to regulate macrophage functions, but the mechanisms governing biogenic amine signaling in and around immune cells remains nebulous. In the central nervous system (CNS), biogenic amine transporters are regarded as the master regulators of neurotransmitter signaling. While we and others have shown that macrophages express these transporters, relatively little is known of their function in these cells. To address these knowledge gaps, we investigated the function of norepinephrine (NET) and dopamine (DAT) transporters on human monocyte-derived macrophages. We found that both NET and DAT are present and can uptake substrate from the extracellular space at baseline. Not only was DAT expressed in cultured monocyte-derived macrophages (MDMs), but it was also detected in a subset of intestinal macrophages in situ. Surprisingly, we discovered a NET-independent, DAT-mediated immuno-modulatory mechanism in response to lipopolysaccharide (LPS). LPS induced reverse transport of dopamine through DAT, engaging an autocrine/paracrine signaling loop that regulated the macrophage response. Removing this signaling loop enhanced the pro-inflammatory response to LPS. Collectively, our data introduce a potential role for DAT in the regulation of innate immunity.
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Affiliation(s)
- Phillip M Mackie
- Department of Neuroscience, University of Florida, Gainesville, United States of America
| | - Adithya Gopinath
- Department of Neuroscience, McKnight Brain Insitute, University of Florida College of Medicine, Gainesville, United States of America
| | - Dominic M Montas
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Alyssa Nielsen
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Aidan Smith
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Rachel A Nolan
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, United States of America
| | - Kaitlyn Runner
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, United States of America
| | - Stephanie M Matt
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, United States of America
| | - John McNamee
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Joshua E Riklan
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Kengo Adachi
- Neuronal Signal Transduction Group, Max Plank Florida Institute for Neuroscience, Jupiter, United States of America
| | - Andria Doty
- Flow Cytometry Core Facility, University of Florida College of Medicine, Gainesville, United States of America
| | - Adolfo Ramirez-Zamora
- Department of Neurology, University of Florida College of Medicine, Gainesville, United States of America
| | - Long Yan
- Neuronal Signal Transduction Group, Max Plank Florida Institute for Neuroscience, Jupiter, United States of America
| | - Peter J Gaskill
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, United States of America
| | - Wolfgang J Streit
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Michael S Okun
- University of Florida College of Medicine, Gainesville, United States of America
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
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4
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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.
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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.
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5
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Ingram SM, Rana T, Manson AM, Yayah FM, Jackson EGB, Anderson C, Davids BO, Goodwin JS. Optogenetically-induced multimerization of the dopamine transporter increases uptake and trafficking to the plasma membrane. J Biol Chem 2021; 296:100787. [PMID: 34015332 PMCID: PMC8203837 DOI: 10.1016/j.jbc.2021.100787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 05/07/2021] [Accepted: 05/13/2021] [Indexed: 11/19/2022] Open
Abstract
The dopamine transporter (DAT) is essential for the reuptake of the released neurotransmitter dopamine (DA) in the brain. Psychostimulants, methamphetamine and cocaine, have been reported to induce the formation of DAT multimeric complexes in vivo and in vitro. The interpretation of DAT multimer function has been primarily in the context of compounds that induce structural and functional modifications of the DAT, complicating the understanding of the significance of DAT multimers. To examine multimerization in the absence of DAT ligands as well as in their presence, we developed a novel, optogenetic fusion chimera of cryptochrome 2 and DAT with an mCherry fluorescent reporter (Cry2-DAT). Using blue light to induce Cry2-DAT multimeric protein complex formation, we were able to simultaneously test the functional contributions of DAT multimerization in the absence or presence of substrates or inhibitors with high spatiotemporal precision. We found that blue light-stimulated Cry2-DAT multimers significantly increased IDT307 uptake and MFZ 9-18 binding in the absence of ligands as well as after methamphetamine and nomifensine treatment. Blue light-induced Cry2-DAT multimerization increased colocalization with recycling endosomal marker Rab11 and had decreased presence in Rab5-positive early endosomes and Rab7-positive late endosomes. Our data suggest that the increased uptake and binding results from induced and rapid trafficking of DAT multimers to the plasma membrane. Our data suggest that DAT multimers may function to help maintain DA homeostasis.
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Affiliation(s)
- Shalonda M Ingram
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - Tanu Rana
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - Ashley M Manson
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - Faisal M Yayah
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - Evan G B Jackson
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - Christopher Anderson
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - Benem-Orom Davids
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - J Shawn Goodwin
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA.
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6
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Lamothe SM, Sharmin N, Silver G, Satou M, Hao Y, Tateno T, Baronas VA, Kurata HT. Control of Slc7a5 sensitivity by the voltage-sensing domain of Kv1 channels. eLife 2020; 9:54916. [PMID: 33164746 PMCID: PMC7690953 DOI: 10.7554/elife.54916] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 11/06/2020] [Indexed: 01/13/2023] Open
Abstract
Many voltage-dependent ion channels are regulated by accessory proteins. We recently reported powerful regulation of Kv1.2 potassium channels by the amino acid transporter Slc7a5. In this study, we report that Kv1.1 channels are also regulated by Slc7a5, albeit with different functional outcomes. In heterologous expression systems, Kv1.1 exhibits prominent current enhancement ('disinhibition') with holding potentials more negative than −120 mV. Knockdown of endogenous Slc7a5 leads to larger Kv1.1 currents and strongly attenuates the disinhibition effect, suggesting that Slc7a5 regulation of Kv1.1 involves channel inhibition that can be reversed by supraphysiological hyperpolarizing voltages. We investigated chimeric combinations of Kv1.1 and Kv1.2, demonstrating that exchange of the voltage-sensing domain controls the sensitivity and response to Slc7a5, and localize a specific position in S1 with prominent effects on Slc7a5 sensitivity. Overall, our study highlights multiple Slc7a5-sensitive Kv1 subunits, and identifies the voltage-sensing domain as a determinant of Slc7a5 modulation of Kv1 channels.
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Affiliation(s)
- Shawn M Lamothe
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Nazlee Sharmin
- School of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, School of Dentistry, Edmonton Clinic Health Academy (ECHA), Edmonton, Canada
| | - Grace Silver
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Motoyasu Satou
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Tochigi, Japan.,Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Yubin Hao
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Toru Tateno
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Victoria A Baronas
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Harley T Kurata
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
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7
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Kessi M, Chen B, Peng J, Tang Y, Olatoutou E, He F, Yang L, Yin F. Intellectual Disability and Potassium Channelopathies: A Systematic Review. Front Genet 2020; 11:614. [PMID: 32655623 PMCID: PMC7324798 DOI: 10.3389/fgene.2020.00614] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/20/2020] [Indexed: 01/15/2023] Open
Abstract
Intellectual disability (ID) manifests prior to adulthood as severe limitations to intellectual function and adaptive behavior. The role of potassium channelopathies in ID is poorly understood. Therefore, we aimed to evaluate the relationship between ID and potassium channelopathies. We hypothesized that potassium channelopathies are strongly associated with ID initiation, and that both gain- and loss-of-function mutations lead to ID. This systematic review explores the burden of potassium channelopathies, possible mechanisms, advancements using animal models, therapies, and existing gaps. The literature search encompassed both PubMed and Embase up to October 2019. A total of 75 articles describing 338 cases were included in this review. Nineteen channelopathies were identified, affecting the following genes: KCNMA1, KCNN3, KCNT1, KCNT2, KCNJ10, KCNJ6, KCNJ11, KCNA2, KCNA4, KCND3, KCNH1, KCNQ2, KCNAB1, KCNQ3, KCNQ5, KCNC1, KCNB1, KCNC3, and KCTD3. Twelve of these genes presented both gain- and loss-of-function properties, three displayed gain-of-function only, three exhibited loss-of-function only, and one had unknown function. How gain- and loss-of-function mutations can both lead to ID remains largely unknown. We identified only a few animal studies that focused on the mechanisms of ID in relation to potassium channelopathies and some of the few available therapeutic options (channel openers or blockers) appear to offer limited efficacy. In conclusion, potassium channelopathies contribute to the initiation of ID in several instances and this review provides a comprehensive overview of which molecular players are involved in some of the most prominent disease phenotypes.
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Affiliation(s)
- Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China.,Kilimanjaro Christian Medical University College, Moshi, Tanzania.,Mawenzi Regional Referral Hospital, Moshi, Tanzania
| | - Baiyu Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Yulin Tang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Eleonore Olatoutou
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
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8
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Fagan RR, Kearney PJ, Sweeney CG, Luethi D, Schoot Uiterkamp FE, Schicker K, Alejandro BS, O'Connor LC, Sitte HH, Melikian HE. Dopamine transporter trafficking and Rit2 GTPase: Mechanism of action and in vivo impact. J Biol Chem 2020; 295:5229-5244. [PMID: 32132171 PMCID: PMC7170531 DOI: 10.1074/jbc.ra120.012628] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/20/2020] [Indexed: 12/20/2022] Open
Abstract
Following its evoked release, dopamine (DA) signaling is rapidly terminated by presynaptic reuptake, mediated by the cocaine-sensitive DA transporter (DAT). DAT surface availability is dynamically regulated by endocytic trafficking, and direct protein kinase C (PKC) activation acutely diminishes DAT surface expression by accelerating DAT internalization. Previous cell line studies demonstrated that PKC-stimulated DAT endocytosis requires both Ack1 inactivation, which releases a DAT-specific endocytic brake, and the neuronal GTPase, Rit2, which binds DAT. However, it is unknown whether Rit2 is required for PKC-stimulated DAT endocytosis in DAergic terminals or whether there are region- and/or sex-dependent differences in PKC-stimulated DAT trafficking. Moreover, the mechanisms by which Rit2 controls PKC-stimulated DAT endocytosis are unknown. Here, we directly examined these important questions. Ex vivo studies revealed that PKC activation acutely decreased DAT surface expression selectively in ventral, but not dorsal, striatum. AAV-mediated, conditional Rit2 knockdown in DAergic neurons impacted baseline DAT surface:intracellular distribution in DAergic terminals from female ventral, but not dorsal, striatum. Further, Rit2 was required for PKC-stimulated DAT internalization in both male and female ventral striatum. FRET and surface pulldown studies in cell lines revealed that PKC activation drives DAT-Rit2 surface dissociation and that the DAT N terminus is required for both PKC-mediated DAT-Rit2 dissociation and DAT internalization. Finally, we found that Rit2 and Ack1 independently converge on DAT to facilitate PKC-stimulated DAT endocytosis. Together, our data provide greater insight into mechanisms that mediate PKC-regulated DAT internalization and reveal unexpected region-specific differences in PKC-stimulated DAT trafficking in bona fide DAergic terminals.
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Affiliation(s)
- Rita R Fagan
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Patrick J Kearney
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Carolyn G Sweeney
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Dino Luethi
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna A-1090, Austria
| | - Florianne E Schoot Uiterkamp
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna A-1090, Austria
| | - Klaus Schicker
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna A-1090, Austria
| | - Brian S Alejandro
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Lauren C O'Connor
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Harald H Sitte
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna A-1090, Austria
| | - Haley E Melikian
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605.
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9
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Fowler PC, Garcia-Pardo ME, Simpson JC, O'Sullivan NC. NeurodegenERation: The Central Role for ER Contacts in Neuronal Function and Axonopathy, Lessons From Hereditary Spastic Paraplegias and Related Diseases. Front Neurosci 2019; 13:1051. [PMID: 31680803 PMCID: PMC6801308 DOI: 10.3389/fnins.2019.01051] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 09/19/2019] [Indexed: 12/17/2022] Open
Abstract
The hereditary spastic paraplegias (HSPs) are a group of inherited neurodegenerative conditions whose characteristic feature is degeneration of the longest axons within the corticospinal tract which leads to progressive spasticity and weakness of the lower limbs. Though highly genetically heterogeneous, the majority of HSP cases are caused by mutations in genes encoding proteins that are responsible for generating and organizing the tubular endoplasmic reticulum (ER). Despite this, the role of the ER within neurons, particularly the long axons affected in HSP, is not well understood. Throughout axons, ER tubules make extensive contacts with other organelles, the cytoskeleton and the plasma membrane. At these ER contacts, protein complexes work in concert to perform specialized functions including organelle shaping, calcium homeostasis and lipid biogenesis, all of which are vital for neuronal survival and may be disrupted by HSP-causing mutations. In this article we summarize the proteins which mediate ER contacts, review the functions these contacts are known to carry out within neurons, and discuss the potential contribution of disruption of ER contacts to axonopathy in HSP.
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Affiliation(s)
- Philippa C Fowler
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - M Elena Garcia-Pardo
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Jeremy C Simpson
- UCD School of Biology and Environmental Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Niamh C O'Sullivan
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
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10
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Wang X, Su Y, Yan H, Huang Z, Huang Y, Yue W. Association Study of KCNH7 Polymorphisms and Individual Responses to Risperidone Treatment in Schizophrenia. Front Psychiatry 2019; 10:633. [PMID: 31543842 PMCID: PMC6728906 DOI: 10.3389/fpsyt.2019.00633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Accepted: 08/06/2019] [Indexed: 12/31/2022] Open
Abstract
Risperidone has been used to treat the symptoms of schizophrenia and to reduce its relapse. However, the responses to treatment show great variability among patients. The potassium channel has been reported as an effective target for antipsychotics. KCNH7, a member of the voltage-gated K+ channel Kv11 family, is primarily expressed in the brain. Here, we assessed the genetic association of KCNH7 with risperidone responses in 393 schizophrenia patients. The patients were treated with risperidone for 6 weeks. The reduction rates of Positive and Negative Syndrome Scale (PANSS) scores were determined to quantify drug response. We also examined the associations between six single-nucleotide polymorphisms (SNPs) of KCNH7 and the risperidone responses for a total of 6 weeks. The SNP rs77699177 (C > T) in the KCNH7 gene intron was significantly associated with the treatment response reflected by the PANSS reduction rate (CC, 55.8 ± 23.0; TC, 70.9 ± 20.3, P = 0.000110), indicating that patients with the TC genotype have better efficacy for antipsychotic therapy. The rs2241240 SNP also showed a significant association with treatment responses after 6 weeks of treatment (P = 0.00256). The findings indicate that the voltage-gated K+ channel KCNH7 is a potential functional marker for the identification of the response to risperidone treatment in schizophrenia patients. Note: The study was registered under clinical trial number ChiCTR-RNC-09000522 (http://www.chictr.org/).
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Affiliation(s)
- Xueping Wang
- Peking University Sixth Hospital, Institute of Mental Health, Beijing, China.,NHC Key Laboratory of Mental Health, Peking University, Beijing, China.,National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital, Beijing, China
| | - Yi Su
- Peking University Sixth Hospital, Institute of Mental Health, Beijing, China.,NHC Key Laboratory of Mental Health, Peking University, Beijing, China.,National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital, Beijing, China
| | - Hao Yan
- Peking University Sixth Hospital, Institute of Mental Health, Beijing, China.,NHC Key Laboratory of Mental Health, Peking University, Beijing, China.,National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital, Beijing, China
| | - Zhuo Huang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education, Beijing, China
| | - Yu Huang
- National Engineering Research Center for Software Engineering, Peking University, Beijing, China
| | - Weihua Yue
- Peking University Sixth Hospital, Institute of Mental Health, Beijing, China.,NHC Key Laboratory of Mental Health, Peking University, Beijing, China.,National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital, Beijing, China
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