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Mohtasham Kia Y, Cannavo A, Bahiraie P, Alilou S, Saeedian B, Babajani N, Ghondaghsaz E, Khalaji A, Behnoush AH. Insights into the Role of Galectin-3 as a Diagnostic and Prognostic Biomarker of Atrial Fibrillation. DISEASE MARKERS 2023; 2023:2097012. [PMID: 37849915 PMCID: PMC10578984 DOI: 10.1155/2023/2097012] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 09/02/2023] [Accepted: 09/20/2023] [Indexed: 10/19/2023]
Abstract
Atrial fibrillation (AF) is an irregular atrial activity and the most prevalent type of arrhythmia. Although AF is easily diagnosed with an electrocardiogram, there is a keen interest in identifying an easy-to-dose biomarker that can predict the prognosis of AF and its recurrence. Galectin-3 (Gal-3) is a beta-galactoside binding protein from the lectin family with pro-fibrotic and -inflammatory effects and a pivotal role in a variety of biological processes, cell proliferation, and differentiation; therefore, it is implicated in the pathogenesis of many cardiovascular (e.g., heart failure (HF)) and noncardiovascular diseases. However, its specificity and sensitivity as a potential marker in AF patients remain debated and controversial. This article comprehensively reviewed the evidence regarding the interplay between Gal-3 and patients with AF. Clinical implications of measuring Gal-3 in AF patients for diagnosis and prognosis are mentioned. Moreover, the role of Gal-3 as a potential biomarker for the management of AF recurrence is investigated. The association of Gal-3 and AF in special populations (coronary artery disease, HF, metabolic syndrome, chronic kidney disease, and diabetes mellitus) has been explored in this review. Overall, although further studies are needed to enlighten the role of Gal-3 in the diagnosis and treatment of AF, our study demonstrated the high potential of this molecule to be used and focused on by researchers and clinicians.
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Affiliation(s)
| | - Alessandro Cannavo
- Department of Translational Medical Sciences, Federico II University of Naples, Naples, Italy
| | - Pegah Bahiraie
- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sanam Alilou
- School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Behrad Saeedian
- School of Medicine, Tehran University of Medical Sciences, Poursina St., Keshavarz Blvd., Tehran 1417613151, Iran
| | - Nastaran Babajani
- School of Medicine, Tehran University of Medical Sciences, Poursina St., Keshavarz Blvd., Tehran 1417613151, Iran
| | - Elina Ghondaghsaz
- Undergraduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada
| | - Amirmohammad Khalaji
- School of Medicine, Tehran University of Medical Sciences, Poursina St., Keshavarz Blvd., Tehran 1417613151, Iran
| | - Amir Hossein Behnoush
- School of Medicine, Tehran University of Medical Sciences, Poursina St., Keshavarz Blvd., Tehran 1417613151, Iran
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2
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Lemaigre C, Ceuppens A, Valades-Cruz CA, Ledoux B, Vanbeneden B, Hassan M, Zetterberg FR, Nilsson UJ, Johannes L, Wunder C, Renard HF, Morsomme P. N-BAR and F-BAR proteins-endophilin-A3 and PSTPIP1-control clathrin-independent endocytosis of L1CAM. Traffic 2023; 24:190-212. [PMID: 36843549 DOI: 10.1111/tra.12883] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/07/2023] [Accepted: 02/18/2023] [Indexed: 02/28/2023]
Abstract
Recent advances in the field demonstrate the high diversity and complexity of endocytic pathways. In the current study, we focus on the endocytosis of L1CAM. This glycoprotein plays a major role in the development of the nervous system, and is involved in cancer development and is associated with metastases and poor prognosis. Two L1CAM isoforms are subject to endocytosis: isoform 1, described as a clathrin-mediated cargo; isoform 2, whose endocytosis has never been studied. Deciphering the molecular machinery of isoform 2 internalisation should contribute to a better understanding of its pathophysiological role. First, we demonstrated in our cellular context that both isoforms of L1CAM are mainly a clathrin-independent cargo, which was not expected for isoform 1. Second, the mechanism of L1CAM endocytosis is specifically mediated by the N-BAR domain protein endophilin-A3. Third, we discovered PSTPIP1, an F-BAR domain protein, as a novel actor in this endocytic process. Finally, we identified galectins as endocytic partners and negative regulators of L1CAM endocytosis. In summary, the interplay of the BAR proteins endophilin-A3 and PSTPIP1, and galectins fine tune the clathrin-independent endocytosis of L1CAM.
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Affiliation(s)
- Camille Lemaigre
- UCLouvain, Louvain Institute of Biomolecular Science and Technology, Group of Molecular Physiology, Louvain-la-Neuve, Belgium
| | - Apolline Ceuppens
- UCLouvain, Louvain Institute of Biomolecular Science and Technology, Group of Molecular Physiology, Louvain-la-Neuve, Belgium
| | - Cesar Augusto Valades-Cruz
- Institut Curie, Université PSL, U1143 INSERM, UMR3666 CNRS, Cellular and Chemical Biology unit, Paris, France.,SERPICO Project Team, UMR144 CNRS Institut Curie, PSL Research University, Paris, France.,SERPICO Project Team, Inria Centre Rennes-Bretagne Atlantique, Campus Universitaire de Beaulieu, Rennes, France
| | - Benjamin Ledoux
- UCLouvain, Louvain Institute of Biomolecular Science and Technology, Group of Molecular Physiology, Louvain-la-Neuve, Belgium
| | - Bastien Vanbeneden
- UCLouvain, Louvain Institute of Biomolecular Science and Technology, Group of Molecular Physiology, Louvain-la-Neuve, Belgium
| | | | | | - Ulf J Nilsson
- Department of Chemistry, Lund University, Lund, Sweden
| | - Ludger Johannes
- Institut Curie, Université PSL, U1143 INSERM, UMR3666 CNRS, Cellular and Chemical Biology unit, Paris, France
| | - Christian Wunder
- Institut Curie, Université PSL, U1143 INSERM, UMR3666 CNRS, Cellular and Chemical Biology unit, Paris, France
| | - Henri-François Renard
- UNamur, NARILIS, Unité de recherche en biologie cellulaire animale (URBC), Namur, Belgium
| | - Pierre Morsomme
- UCLouvain, Louvain Institute of Biomolecular Science and Technology, Group of Molecular Physiology, Louvain-la-Neuve, Belgium
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3
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Nguyen NH, Brodsky JL. The cellular pathways that maintain the quality control and transport of diverse potassium channels. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194908. [PMID: 36638864 PMCID: PMC9908860 DOI: 10.1016/j.bbagrm.2023.194908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/20/2022] [Accepted: 01/03/2023] [Indexed: 01/12/2023]
Abstract
Potassium channels are multi-subunit transmembrane proteins that permit the selective passage of potassium and play fundamental roles in physiological processes, such as action potentials in the nervous system and organismal salt and water homeostasis, which is mediated by the kidney. Like all ion channels, newly translated potassium channels enter the endoplasmic reticulum (ER) and undergo the error-prone process of acquiring post-translational modifications, folding into their native conformations, assembling with other subunits, and trafficking through the secretory pathway to reach their final destinations, most commonly the plasma membrane. Disruptions in these processes can result in detrimental consequences, including various human diseases. Thus, multiple quality control checkpoints evolved to guide potassium channels through the secretory pathway and clear potentially toxic, aggregation-prone misfolded species. We will summarize current knowledge on the mechanisms underlying potassium channel quality control in the secretory pathway, highlight diseases associated with channel misfolding, and suggest potential therapeutic routes.
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Affiliation(s)
- Nga H Nguyen
- Department of Biological Sciences, University of Pittsburgh, A320 Langley Hall, Pittsburgh, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, A320 Langley Hall, Pittsburgh, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA.
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4
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Hager NA, McAtee CK, Lesko MA, O’Donnell AF. Inwardly Rectifying Potassium Channel Kir2.1 and its "Kir-ious" Regulation by Protein Trafficking and Roles in Development and Disease. Front Cell Dev Biol 2022; 9:796136. [PMID: 35223865 PMCID: PMC8864065 DOI: 10.3389/fcell.2021.796136] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 12/15/2021] [Indexed: 11/13/2022] Open
Abstract
Potassium (K+) homeostasis is tightly regulated for optimal cell and organismal health. Failure to control potassium balance results in disease, including cardiac arrythmias and developmental disorders. A family of inwardly rectifying potassium (Kir) channels helps cells maintain K+ levels. Encoded by KCNJ genes, Kir channels are comprised of a tetramer of Kir subunits, each of which contains two-transmembrane domains. The assembled Kir channel generates an ion selectivity filter for K+ at the monomer interface, which allows for K+ transit. Kir channels are found in many cell types and influence K+ homeostasis across the organism, impacting muscle, nerve and immune function. Kir2.1 is one of the best studied family members with well-defined roles in regulating heart rhythm, muscle contraction and bone development. Due to their expansive roles, it is not surprising that Kir mutations lead to disease, including cardiomyopathies, and neurological and metabolic disorders. Kir malfunction is linked to developmental defects, including underdeveloped skeletal systems and cerebellar abnormalities. Mutations in Kir2.1 cause the periodic paralysis, cardiac arrythmia, and developmental deficits associated with Andersen-Tawil Syndrome. Here we review the roles of Kir family member Kir2.1 in maintaining K+ balance with a specific focus on our understanding of Kir2.1 channel trafficking and emerging roles in development and disease. We provide a synopsis of the vital work focused on understanding the trafficking of Kir2.1 and its role in development.
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Affiliation(s)
| | | | | | - Allyson F. O’Donnell
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, United States
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5
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Estadella I, Pedrós-Gámez O, Colomer-Molera M, Bosch M, Sorkin A, Felipe A. Endocytosis: A Turnover Mechanism Controlling Ion Channel Function. Cells 2020; 9:E1833. [PMID: 32759790 PMCID: PMC7463639 DOI: 10.3390/cells9081833] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/30/2020] [Accepted: 08/02/2020] [Indexed: 01/08/2023] Open
Abstract
Ion channels (IChs) are transmembrane proteins that selectively drive ions across membranes. The function of IChs partially relies on their abundance and proper location in the cell, fine-tuned by the delicate balance between secretory, endocytic, and degradative pathways. The disruption of this balance is associated with several diseases, such as Liddle's and long QT syndromes. Because of the vital role of these proteins in human health and disease, knowledge of ICh turnover is essential. Clathrin-dependent and -independent mechanisms have been the primary mechanisms identified with ICh endocytosis and degradation. Several molecular determinants recognized by the cellular internalization machinery have been discovered. Moreover, specific conditions can trigger the endocytosis of many IChs, such as the activation of certain receptors, hypokalemia, and some drugs. Ligand-dependent receptor activation primarily results in the posttranslational modification of IChs and the recruitment of important mediators, such as β-arrestins and ubiquitin ligases. However, endocytosis is not a final fate. Once internalized into endosomes, IChs are either sorted to lysosomes for degradation or recycled back to the plasma membrane. Rab proteins are crucial participants during these turnover steps. In this review, we describe the major ICh endocytic pathways, the signaling inputs triggering ICh internalization, and the key mediators of this essential cellular process.
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Affiliation(s)
- Irene Estadella
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, 08028 Barcelona, Spain; (I.E.); (O.P.-G.); (M.C.-M.); (M.B.)
| | - Oriol Pedrós-Gámez
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, 08028 Barcelona, Spain; (I.E.); (O.P.-G.); (M.C.-M.); (M.B.)
| | - Magalí Colomer-Molera
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, 08028 Barcelona, Spain; (I.E.); (O.P.-G.); (M.C.-M.); (M.B.)
| | - Manel Bosch
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, 08028 Barcelona, Spain; (I.E.); (O.P.-G.); (M.C.-M.); (M.B.)
- Centres Científics i Tecnològics de la Universitat de Barcelona (CCiTUB), Universitat de Barcelona, 08028 Barcelona, Spain
| | - Alexander Sorkin
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA;
| | - Antonio Felipe
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, 08028 Barcelona, Spain; (I.E.); (O.P.-G.); (M.C.-M.); (M.B.)
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6
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Ríos H, Paganelli AR, Fosser NS. The role of PDLIM1, a PDZ-LIM domain protein, at the ribbon synapses in the chicken retina. J Comp Neurol 2020; 528:1820-1832. [PMID: 31930728 DOI: 10.1002/cne.24855] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 01/29/2023]
Abstract
PDLIM's protein family is involved in the rearrangement of the actin cytoskeleton. In the present study, we describe the localization of PDLIM1 in chicken photoreceptors. This study provides evidence that this protein is present at the cone pedicles, as well as in other synapses of the chicken retina. Here, we demonstrate the expression pattern of PDLIM1 through immunofluorescence staining, immunoblots, subcellular fractionation, and immunoprecipitation experiments. Also, we consider the possibility that PDLIM1 may be involved in the synaptic vesicle endocytosis and/or the presynaptic trafficking of synaptic vesicles back to the nonready releasable pool. This endocytotic/exocytotic coupling requires a tight link between exocytic vesicle fusion at defined release sites and endocytic retrieval of synaptic vesicle membranes. In turn, photoreceptor ribbon synaptic structure depends on the cytoskeleton arrangement, both at the active zone-related with exocytosis-as well as at the endocytic zone-periactive zone. To our knowledge, the PDLIM1 protein has not been observed in the pre synapses of the retina. Thus, the present study describes the expression and subcellular localization of PDLIM1 for the first time, as well as its modulation by visual environment in the chicken retina.
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Affiliation(s)
- Hugo Ríos
- Universidad de Buenos Aires, Facultad de Medicina, I° U.A. Histología, Embriología, Biología Celular y Genética, Ciudad de Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis" (IBCN), Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - Alejandra R Paganelli
- Universidad de Buenos Aires, Facultad de Medicina, I° U.A. Histología, Embriología, Biología Celular y Genética, Ciudad de Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis" (IBCN), Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - Nicolás S Fosser
- Universidad de Buenos Aires, Facultad de Medicina, I° U.A. Histología, Embriología, Biología Celular y Genética, Ciudad de Buenos Aires, Argentina
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7
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Endocytic Adaptor Proteins in Health and Disease: Lessons from Model Organisms and Human Mutations. Cells 2019; 8:cells8111345. [PMID: 31671891 PMCID: PMC6912373 DOI: 10.3390/cells8111345] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 12/11/2022] Open
Abstract
Cells need to exchange material and information with their environment. This is largely achieved via cell-surface receptors which mediate processes ranging from nutrient uptake to signaling responses. Consequently, their surface levels have to be dynamically controlled. Endocytosis constitutes a powerful mechanism to regulate the surface proteome and to recycle vesicular transmembrane proteins that strand at the plasma membrane after exocytosis. For efficient internalization, the cargo proteins need to be linked to the endocytic machinery via adaptor proteins such as the heterotetrameric endocytic adaptor complex AP-2 and a variety of mostly monomeric endocytic adaptors. In line with the importance of endocytosis for nutrient uptake, cell signaling and neurotransmission, animal models and human mutations have revealed that defects in these adaptors are associated with several diseases ranging from metabolic disorders to encephalopathies. This review will discuss the physiological functions of the so far known adaptor proteins and will provide a comprehensive overview of their links to human diseases.
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8
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OSR1 regulates a subset of inward rectifier potassium channels via a binding motif variant. Proc Natl Acad Sci U S A 2018; 115:3840-3845. [PMID: 29581290 DOI: 10.1073/pnas.1802339115] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The with-no-lysine (K) (WNK) signaling pathway to STE20/SPS1-related proline- and alanine-rich kinase (SPAK) and oxidative stress-responsive 1 (OSR1) kinase is an important mediator of cell volume and ion transport. SPAK and OSR1 associate with upstream kinases WNK 1-4, substrates, and other proteins through their C-terminal domains which interact with linear R-F-x-V/I sequence motifs. In this study we find that SPAK and OSR1 also interact with similar affinity with a motif variant, R-x-F-x-V/I. Eight of 16 human inward rectifier K+ channels have an R-x-F-x-V motif. We demonstrate that two of these channels, Kir2.1 and Kir2.3, are activated by OSR1, while Kir4.1, which does not contain the motif, is not sensitive to changes in OSR1 or WNK activity. Mutation of the motif prevents activation of Kir2.3 by OSR1. Both siRNA knockdown of OSR1 and chemical inhibition of WNK activity disrupt NaCl-induced plasma membrane localization of Kir2.3. Our results suggest a mechanism by which WNK-OSR1 enhance Kir2.1 and Kir2.3 channel activity by increasing their plasma membrane localization. Regulation of members of the inward rectifier K+ channel family adds functional and mechanistic insight into the physiological impact of the WNK pathway.
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9
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Matsuoka H, Inoue M. Molecular mechanism for muscarinic M 1 receptor-mediated endocytosis of TWIK-related acid-sensitive K + 1 channels in rat adrenal medullary cells. J Physiol 2017; 595:6851-6867. [PMID: 28944482 DOI: 10.1113/jp275039] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 09/15/2017] [Indexed: 01/25/2023] Open
Abstract
KEY POINTS The muscarinic acetylcholine receptor (mAChR)-mediated increase in excitability in rat adrenal medullary cells is at least in part due to inhibition of TWIK (tandem of P domains in a weak inwardly rectifying K+ channel)-related acid-sensitive K+ (TASK)1 channels. In this study we focused on the molecular mechanism of mAChR-mediated inhibition of TASK1 channels. Exposure to muscarine resulted in a clathrin-dependent endocytosis of TASK1 channels following activation of the muscarinic M1 receptor (M1 R). This muscarinic signal for the endocytosis was mediated in sequence by phospholipase C (PLC), protein kinase C (PKC), and then the non-receptor tyrosine kinase Src with the consequent tyrosine phosphorylation of TASK1. The present results establish that TASK1 channels are tyrosine phosphorylated and internalized in a clathrin-dependent manner in response to M1 R stimulation and this translocation is at least in part responsible for muscarinic inhibition of TASK1 channels in rat AM cells. ABSTRACT Activation of muscarinic receptor (mAChR) in rat adrenal medullary (AM) cells induces depolarization through the inhibition of TWIK-related acid-sensitive K+ (TASK)1 channels. Here, pharmacological and immunological approaches were used to elucidate the molecular mechanism for this mAChR-mediated inhibition. TASK1-like immunoreactive (IR) material was mainly located at the cell periphery in dissociated rat AM cells, and its majority was internalized in response to muscarine. The muscarine-induced inward current and translocation of TASK1 were suppressed by dynasore, a dynamin inhibitor. The muscarinic translocation was suppressed by MT7, a specific M1 antagonist, and the dose-response curves for muscarinic agonist-induced translocation were similar to those for the muscarinic inhibition of TASK1 currents. The muscarine-induced inward current and/or translocation of TASK1 were suppressed by inhibitors for phospholipase C (PLC), protein kinase C (PKC), and/or Src. TASK1 channels in AM cells and PC12 cells were transiently associated with Src and were tyrosine phosphorylated in response to muscarinic stimulation. After internalization, TASK1 channels were quickly dephosphorylated even while they remained in the cytoplasm. The cytoplasmic TASK1-like IR material quickly recycled back to the cell periphery after muscarine stimulation for 0.5 min, but not 10 min. We conclude that M1 R stimulation results in internalization of TASK1 channels through the PLC-PKC-Src pathway with the consequent phosphorylation of tyrosine and that this M1 R-mediated internalization is at least in part responsible for muscarinic inhibition of TASK1 channels in rat AM cells.
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Affiliation(s)
- Hidetada Matsuoka
- Department of Cell and Systems Physiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, 807-8555, Japan
| | - Masumi Inoue
- Department of Cell and Systems Physiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, 807-8555, Japan
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10
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Gururaj S, Evely KM, Pryce KD, Li J, Qu J, Bhattacharjee A. Protein kinase A-induced internalization of Slack channels from the neuronal membrane occurs by adaptor protein-2/clathrin-mediated endocytosis. J Biol Chem 2017; 292:19304-19314. [PMID: 28982974 DOI: 10.1074/jbc.m117.804716] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/13/2017] [Indexed: 02/01/2023] Open
Abstract
The sodium-activated potassium (KNa) channel Kcnt1 (Slack) is abundantly expressed in nociceptor (pain-sensing) neurons of the dorsal root ganglion (DRG), where they transmit the large outward conductance IKNa and arbitrate membrane excitability. Slack channel expression at the DRG membrane is necessary for their characteristic firing accommodation during maintained stimulation, and reduced membrane channel density causes hyperexcitability. We have previously shown that in a pro-inflammatory state, a decrease in membrane channel expression leading to reduced Slack-mediated IKNa expression underlies DRG neuronal sensitization. An important component of the inflammatory milieu, PKA internalizes Slack channels from the DRG membrane, reduces IKNa, and produces DRG neuronal hyperexcitability when activated in cultured primary DRG neurons. Here, we show that this PKA-induced retrograde trafficking of Slack channels also occurs in intact spinal cord slices and that it is carried out by adaptor protein-2 (AP-2) via clathrin-mediated endocytosis. We provide mass spectrometric and biochemical evidence of an association of native neuronal AP-2 adaptor proteins with Slack channels, facilitated by a dileucine motif housed in the cytoplasmic Slack C terminus that binds AP-2. By creating a competitive peptide blocker of AP-2-Slack binding, we demonstrated that this interaction is essential for clathrin recruitment to the DRG membrane, Slack channel endocytosis, and DRG neuronal hyperexcitability after PKA activation. Together, these findings uncover AP-2 and clathrin as players in Slack channel regulation. Given the significant role of Slack in nociceptive neuronal excitability, the AP-2 clathrin-mediated endocytosis trafficking mechanism may enable targeting of peripheral and possibly, central neuronal sensitization.
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Affiliation(s)
| | - Katherine M Evely
- the Program for Neuroscience, University at Buffalo, State University of New York, Buffalo, New York 14214 and
| | - Kerri D Pryce
- From the Department of Pharmacology and Toxicology and
| | - Jun Li
- the New York State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, New York 14203
| | - Jun Qu
- the New York State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, New York 14203
| | - Arin Bhattacharjee
- From the Department of Pharmacology and Toxicology and .,the Program for Neuroscience, University at Buffalo, State University of New York, Buffalo, New York 14214 and
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11
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Alcohol Regulates BK Surface Expression via Wnt/β-Catenin Signaling. J Neurosci 2017; 36:10625-10639. [PMID: 27733613 DOI: 10.1523/jneurosci.0491-16.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 07/27/2016] [Indexed: 12/26/2022] Open
Abstract
It has been suggested that drug tolerance represents a form of learning and memory, but this has not been experimentally established at the molecular level. We show that a component of alcohol molecular tolerance (channel internalization) from rat hippocampal neurons requires protein synthesis, in common with other forms of learning and memory. We identify β-catenin as a primary necessary protein. Alcohol increases β-catenin, and blocking accumulation of β-catenin blocks alcohol-induced internalization in these neurons. In transfected HEK293 cells, suppression of Wnt/β-catenin signaling blocks ethanol-induced internalization. Conversely, activation of Wnt/β-catenin reduces BK current density. A point mutation in a putative glycogen synthase kinase phosophorylation site within the S10 region of BK blocks internalization, suggesting that Wnt/β-catenin directly regulates alcohol-induced BK internalization via glycogen synthase kinase phosphorylation. These findings establish de novo protein synthesis and Wnt/β-catenin signaling as critical in mediating a persistent form of BK molecular alcohol tolerance establishing a commonality with other forms of long-term plasticity. SIGNIFICANCE STATEMENT Alcohol tolerance is a key step toward escalating alcohol consumption and subsequent dependence. Our research aims to make significant contributions toward novel, therapeutic approaches to prevent and treat alcohol misuse by understanding the molecular mechanisms of alcohol tolerance. In our current study, we identify the role of a key regulatory pathway in alcohol-induced persistent molecular changes within the hippocampus. The canonical Wnt/β-catenin pathway regulates BK channel surface expression in a protein synthesis-dependent manner reminiscent of other forms of long-term hippocampal neuronal adaptations. This unique insight opens the possibility of using clinically tested drugs, targeting the Wnt/β-catenin pathway, for the novel use of preventing and treating alcohol dependency.
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12
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Kyung JW, Cho IH, Lee S, Song WK, Ryan TA, Hoppa MB, Kim SH. Adaptor Protein 2 (AP-2) complex is essential for functional axogenesis in hippocampal neurons. Sci Rep 2017; 7:41620. [PMID: 28139716 PMCID: PMC5282494 DOI: 10.1038/srep41620] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 12/21/2016] [Indexed: 11/18/2022] Open
Abstract
The complexity and diversity of a neural network requires regulated elongation and branching of axons, as well as the formation of synapses between neurons. In the present study we explore the role of AP-2, a key endocytic adaptor protein complex, in the development of rat hippocampal neurons. We found that the loss of AP-2 during the early stage of development resulted in impaired axon extension and failed maturation of the axon initial segment (AIS). Normally the AIS performs two tasks in concert, stabilizing neural polarity and generating action potentials. In AP-2 silenced axons polarity is established, however there is a failure to establish action potential firing. Consequently, this impairs activity-driven Ca2+ influx and exocytosis at nerve terminals. In contrast, removal of AP-2 from older neurons does not impair axonal growth or signaling and synaptic function. Our data reveal that AP-2 has important roles in functional axogenesis by proper extension of axon as well as the formation of AIS during the early step of neurodevelopment.
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Affiliation(s)
- Jae Won Kyung
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, 02447, South Korea
| | - In Ha Cho
- Department of Biology, Molecular Cellular Biology Program, Dartmouth College, Hanover, NH, 03755, USA
| | - Sukmook Lee
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute, Chuncheon, 24341, South Korea
| | - Woo Keun Song
- School of Life Science, Bioimaging Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, South Korea
| | - Timothy A Ryan
- Department of Biochemistry, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Michael B Hoppa
- Department of Biology, Molecular Cellular Biology Program, Dartmouth College, Hanover, NH, 03755, USA
| | - Sung Hyun Kim
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, 02447, South Korea.,Department of Physiology, Neurodegeneration Control Research Center, School of Medicine, Kyung Hee University, Seoul, 02447, South Korea
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13
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Kortvely E, Hauck SM, Behler J, Ho N, Ueffing M. The unconventional secretion of ARMS2. Hum Mol Genet 2016; 25:3143-3151. [DOI: 10.1093/hmg/ddw162] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/18/2016] [Accepted: 05/19/2016] [Indexed: 11/13/2022] Open
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14
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Takemoto Y, Ramirez RJ, Yokokawa M, Kaur K, Ponce-Balbuena D, Sinno MC, Willis BC, Ghanbari H, Ennis SR, Guerrero-Serna G, Henzi BC, Latchamsetty R, Ramos-Mondragon R, Musa H, Martins RP, Pandit SV, Noujaim SF, Crawford T, Jongnarangsin K, Pelosi F, Bogun F, Chugh A, Berenfeld O, Morady F, Oral H, Jalife J. Galectin-3 Regulates Atrial Fibrillation Remodeling and Predicts Catheter Ablation Outcomes. JACC Basic Transl Sci 2016; 1:143-154. [PMID: 27525318 PMCID: PMC4979747 DOI: 10.1016/j.jacbts.2016.03.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Atrial fibrillation (AF) usually starts as paroxysmal but can evolve relentlessly to the persistent and permanent forms. However, the mechanisms governing such a transition are unknown. The authors show that intracardiac serum levels of galectin (Gal)-3 are greater in patients with persistent than paroxysmal AF and that Gal-3 independently predicts atrial tachyarrhythmia recurrences after a single ablation procedure. Using a sheep model of persistent AF the authors further demonstrate that upstream therapy targeting Gal-3 diminishes both electrical remodeling and fibrosis by impairing transforming growth factor beta–mediated signaling and reducing myofibroblast activation. Accordingly, Gal-3 inhibition therapy increases the probability of AF termination and reduces the overall burden of AF. Therefore the authors postulate that Gal-3 inhibition is a potential new upstream therapy to prevent AF progression. Intracardiac serum galectin (Gal)-3 levels are shown to be greater in patients with persistent than paroxysmal atrial fibrillation (AF), and the Gal-3 level was an independent predictor of AF recurrences after a single ablation procedure. In a sheep model, the Gal-3 inhibitor GM-CT-01 (GMCT) reduced atrial fibroblast proliferation in vitro. GMCT mitigated atrial dilation, myocyte hypertrophy, fibrosis, and the expected increase in DF during transition to persistent AF. GMCT-treated sheep hearts had longer action potential durations, and fewer rotors and wavebreaks during AF than control. GMCT increased the number of spontaneous AF terminations and reduced overall AF burden.
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Affiliation(s)
- Yoshio Takemoto
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Rafael J Ramirez
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Miki Yokokawa
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Kuljeet Kaur
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Daniela Ponce-Balbuena
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Mohamad C Sinno
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - B Cicero Willis
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Hamid Ghanbari
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Steven R Ennis
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Guadalupe Guerrero-Serna
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Bettina C Henzi
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Rakesh Latchamsetty
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Roberto Ramos-Mondragon
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Hassan Musa
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Raphael P Martins
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Sandeep V Pandit
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Sami F Noujaim
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA
| | - Thomas Crawford
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Krit Jongnarangsin
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Frank Pelosi
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Frank Bogun
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Aman Chugh
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Omer Berenfeld
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Fred Morady
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Hakan Oral
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - José Jalife
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
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15
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Talantikite M, Berenguer M, Gonzalez T, Alessi MC, Poggi M, Peiretti F, Govers R. The first intracellular loop of GLUT4 contains a retention motif. J Cell Sci 2016; 129:2273-84. [DOI: 10.1242/jcs.183525] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 04/20/2016] [Indexed: 01/02/2023] Open
Abstract
Glucose transporter GLUT4 plays a major role in glucose homeostasis and is efficiently retained intracellularly in adipocytes and myocytes. To simplify the analysis of its retention, various intracellular GLUT4 domains were fused individually to reporter molecules. Of the four short cytoplasmic loops of GLUT4, only the first nine-residue-long loop conferred intracellular retention of truncated forms of the transferrin receptor and CD4 in adipocytes. In contrast, the same loop of GLUT1 was without effect. The reporter molecules to which the first loop of GLUT4 was fused localized, unlike GLUT4, to the TGN, possibly explaining why these molecules did not respond to insulin. The retention induced by the GLUT4 loop was specific to adipocytes as it did not induce retention in preadipocytes. Of the SQWLGRKRA sequence that constitutes this loop, mutation of either the tryptophan or lysine residue abrogated reporter retention. Mutation of these residues individually into alanines in the full-length GLUT4 molecule resulted in a decreased retention for GLUT4-W105A. We conclude that the first intracellular loop of GLUT4 contains retention motif WLGRK, in which Trp105 plays a prominent role.
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Affiliation(s)
- Maya Talantikite
- Inserm U1062, INRA1260, Aix Marseille University, Faculty of Medicine, Marseille F-13385, France
| | - Marion Berenguer
- Inserm U895, Mediterranean Research Center for Molecular Medicine (C3M), Nice, F-06204, France
| | - Teresa Gonzalez
- Inserm U1062, INRA1260, Aix Marseille University, Faculty of Medicine, Marseille F-13385, France
| | - Marie Christine Alessi
- Inserm U1062, INRA1260, Aix Marseille University, Faculty of Medicine, Marseille F-13385, France
| | - Marjorie Poggi
- Inserm U1062, INRA1260, Aix Marseille University, Faculty of Medicine, Marseille F-13385, France
| | - Franck Peiretti
- Inserm U1062, INRA1260, Aix Marseille University, Faculty of Medicine, Marseille F-13385, France
| | - Roland Govers
- Inserm U1062, INRA1260, Aix Marseille University, Faculty of Medicine, Marseille F-13385, France
- Inserm U895, Mediterranean Research Center for Molecular Medicine (C3M), Nice, F-06204, France
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16
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Protein Network Interacting with BK Channels. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2016; 128:127-61. [DOI: 10.1016/bs.irn.2016.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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17
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Huang SS, Chen CL, Huang FW, Johnson FE, Huang JS. Ethanol Enhances TGF-β Activity by Recruiting TGF-β Receptors From Intracellular Vesicles/Lipid Rafts/Caveolae to Non-Lipid Raft Microdomains. J Cell Biochem 2015; 117:860-71. [PMID: 26419316 DOI: 10.1002/jcb.25389] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 09/28/2015] [Indexed: 12/16/2022]
Abstract
Regular consumption of moderate amounts of ethanol has important health benefits on atherosclerotic cardiovascular disease (ASCVD). Overindulgence can cause many diseases, particularly alcoholic liver disease (ALD). The mechanisms by which ethanol causes both beneficial and harmful effects on human health are poorly understood. Here we demonstrate that ethanol enhances TGF-β-stimulated luciferase activity with a maximum of 0.5-1% (v/v) in Mv1Lu cells stably expressing a luciferase reporter gene containing Smad2-dependent elements. In Mv1Lu cells, 0.5% ethanol increases the level of P-Smad2, a canonical TGF-β signaling sensor, by ∼ 2-3-fold. Ethanol (0.5%) increases cell-surface expression of the type II TGF-β receptor (TβR-II) by ∼ 2-3-fold from its intracellular pool, as determined by I(125) -TGF-β-cross-linking/Western blot analysis. Sucrose density gradient ultracentrifugation and indirect immunofluorescence staining analyses reveal that ethanol (0.5% and 1%) also displaces cell-surface TβR-I and TβR-II from lipid rafts/caveolae and facilitates translocation of these receptors to non-lipid raft microdomains where canonical signaling occurs. These results suggest that ethanol enhances canonical TGF-β signaling by increasing non-lipid raft microdomain localization of the TGF-β receptors. Since TGF-β plays a protective role in ASCVD but can also cause ALD, the TGF-β enhancer activity of ethanol at low and high doses appears to be responsible for both beneficial and harmful effects. Ethanol also disrupts the location of lipid raft/caveolae of other membrane proteins (e.g., neurotransmitter, growth factor/cytokine, and G protein-coupled receptors) which utilize lipid rafts/caveolae as signaling platforms. Displacement of these membrane proteins induced by ethanol may result in a variety of pathologies in nerve, heart and other tissues.
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Affiliation(s)
| | - Chun-Lin Chen
- Department of Biological Science, National Sun Yat-sen University, Kaohsiung, 804, Taiwan.,Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University and Academia Sinica, Kaohsiung, 804, Taiwan
| | - Franklin W Huang
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, 02115.,Harvard Medical School, Boston, Massachusetts, 02115
| | - Frank E Johnson
- Department of Surgery, Saint Louis University School of Medicine, St. Louis, Missouri, 63104
| | - Jung San Huang
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Doisy Research Center, St. Louis, Missouri, 63104
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18
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Abstract
The AP (adaptor protein) complexes are heterotetrameric protein complexes that mediate intracellular membrane trafficking along endocytic and secretory transport pathways. There are five different AP complexes: AP-1, AP-2 and AP-3 are clathrin-associated complexes; whereas AP-4 and AP-5 are not. These five AP complexes localize to different intracellular compartments and mediate membrane trafficking in distinct pathways. They recognize and concentrate cargo proteins into vesicular carriers that mediate transport from a donor membrane to a target organellar membrane. AP complexes play important roles in maintaining the normal physiological function of eukaryotic cells. Dysfunction of AP complexes has been implicated in a variety of inherited disorders, including: MEDNIK (mental retardation, enteropathy, deafness, peripheral neuropathy, ichthyosis and keratodermia) syndrome, Fried syndrome, HPS (Hermansky-Pudlak syndrome) and HSP (hereditary spastic paraplegia).
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Key Words
- adaptor protein complex
- arf1
- membrane trafficking
- polarized sorting
- signal recognition
- ampa, α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid
- ap, adaptor protein
- app, amyloid precursor protein
- arf, adp-ribosylation factors
- bfa, brefeldin a
- casr, calcium-sensing receptor
- copi, coatamer protein i
- egfr, epidermal growth factor receptor
- fhh3, familial hypocalciuric hypercalcaemia type 3
- hps, hermansky–pudlak syndrome
- hsp, hereditary spastic paraplegia
- lro, lysosome-related organelle
- mednik, mental retardation, enteropathy, deafness, peripheral neuropathy, ichthyosis and keratodermia
- pi4p, phosphatidylinositol 4 phosphate
- pip2, phosphatidylinositol (4,5)-bisphosphate
- re, recycling endosome
- spg, spastic paraplegia
- tgn, trans-golgi network
- vps41, vacuolar protein sorting 41
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Affiliation(s)
- Sang Yoon Park
- *Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, 20892, U.S.A
| | - Xiaoli Guo
- *Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, 20892, U.S.A
- 1To whom correspondence should be addressed (email )
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Nerve growth factor-induced endocytosis of TWIK-related acid-sensitive K+ 1 channels in adrenal medullary cells and PC12 cells. Pflugers Arch 2013; 465:1051-64. [DOI: 10.1007/s00424-013-1222-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 01/13/2013] [Accepted: 01/20/2013] [Indexed: 11/27/2022]
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20
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Inhibiting the clathrin-mediated endocytosis pathway rescues KIR2.1 downregulation by pentamidine. Pflugers Arch 2012. [DOI: 10.1007/s00424-012-1189-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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21
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Ortega B, Mason AK, Welling PA. A tandem Di-hydrophobic motif mediates clathrin-dependent endocytosis via direct binding to the AP-2 ασ2 subunits. J Biol Chem 2012; 287:26867-75. [PMID: 22711530 DOI: 10.1074/jbc.m112.341990] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Select plasma membrane proteins can be marked as cargo for inclusion into clathrin-coated pits by common internalization signals (e.g. YXXΦ, dileucine motifs, NPXY) that serve as universal recognition sites for the AP-2 adaptor complex or other clathrin-associated sorting proteins. However, some surface proteins, such as the Kir2.3 potassium channel, lack canonical signals but are still targeted for clathrin-dependent endocytosis. Here, we explore the mechanism. We found an unusual endocytic signal in Kir2.3 that is based on two consecutive pairs of hydrophobic residues. Characterized by the sequence ΦΦXΦΦ (a tandem di-hydrophobic (TDH) motif, where Φ is a hydrophobic amino acid), the signal shows no resemblance to other endocytic motifs, yet it directly interacts with AP-2 to target the Kir2.3 potassium channel into the endocytic pathway. We found that the tandem di-hydrophobic motif directly binds to the ασ2 subunits of AP-2, interacting within a large hydrophobic cleft that encompasses part of the docking site for di-Leu signals, but includes additional structures. These observations expand the repertoire of clathrin-dependent internalization signals and the ways in which AP-2 can coordinate endocytosis of cargo proteins.
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Affiliation(s)
- Bernardo Ortega
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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22
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SLC41A1 Mg2+ transport is regulated via Mg2+-dependent endosomal recycling through its N-terminal cytoplasmic domain. Biochem J 2011; 439:129-39. [DOI: 10.1042/bj20110807] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
SLC41A1 (solute carrier family 41, member A1) is a recently described vertebrate member of the MgtE family of Mg2+ transporters. Although MgtE transporters are found in both prokaryotic and eukaryotic organisms, and are highly conserved, little is known about the regulation of their Mg2+ transport function. In the present study, we have shown that endogenous SLC41A1 transporter expression is post-transcriptionally regulated by extracellular Mg2+ in TRPM7 (transient receptor potential cation channel, subfamily M, member 7)-deficient cells, suggesting that SLC41A1 transporters underlie a novel plasma membrane Mg2+ transport function. Consistent with this conclusion, structure–function analyses of heterologous SLC41A1 transporter expression demonstrate that SLC41A1 transporters exhibit the same plasma membrane orientation as homologous bacterial MgtE proteins, are capable of complementing growth of TRPM7-deficient cells only when the Mg2+ transporting pore is intact, and require an N-terminal cytoplasmic domain for Mg2+-dependent regulation of lysosomal degradation and surface expression. Taken together, our results indicate that SLC41A1 proteins are a central component of vertebrate Mg2+ transport systems, and that their Mg2+ transport function is regulated primarily through an endosomal recycling mechanism involving the SLC41A1 N-terminal cytoplasmic domain.
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Bruederle CE, Gay J, Shyng SL. A role of the sulfonylurea receptor 1 in endocytic trafficking of ATP-sensitive potassium channels. Traffic 2011; 12:1242-56. [PMID: 21649805 DOI: 10.1111/j.1600-0854.2011.01227.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The ATP-sensitive potassium (K(ATP) ) channel consisting of sulfonylurea receptor 1 (SUR1) and inward-rectifier potassium channel 6.2 (Kir6.2) has a well-established role in insulin secretion. Mutations in either subunit can lead to disease due to aberrant channel gating, altered channel density at the cell surface or a combination of both. Endocytic trafficking of channels at the plasma membrane is one way to influence surface channel numbers. It has been previously reported that channel endocytosis is dependent on a tyrosine-based motif in Kir6.2, while SUR1 alone is unable to internalize. In this study, we followed endocytic trafficking of surface channels in real time by live-cell imaging of channel subunits tagged with an extracellular minimal α-bungarotoxin-binding peptide labeled with a fluorescent dye. We show that SUR1 undergoes endocytosis independent of Kir6.2. Moreover, mutations in the putative endocytosis motif of Kir6.2, Y330C, Y330A and F333I are unable to prevent channel endocytosis. These findings challenge the notion that Kir6.2 bears the sole endocytic signal for K(ATP) channels and support a role of SUR1 in this trafficking process.
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Affiliation(s)
- Cathrin E Bruederle
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR 97239, USA.
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Lukashova V, Szabó EZ, Jinadasa T, Mokhov A, Litchfield DW, Orlowski J. CK2 phosphorylation of an acidic Ser/Thr di-isoleucine motif in the Na+/H+ exchanger NHE5 isoform promotes association with beta-arrestin2 and endocytosis. J Biol Chem 2011; 286:11456-68. [PMID: 21296876 DOI: 10.1074/jbc.m110.182881] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Internalization of the Na(+)/H(+) exchanger NHE5 into recycling endosomes is enhanced by the endocytic adaptor proteins β-arrestin1 and -2, best known for their preferential recognition of ligand-activated G protein-coupled receptors (GPCRs). However, the mechanism underlying their atypical association with non-GPCRs, such as NHE5, is unknown. In this study, we identified a highly acidic, serine/threonine-rich, di-isoleucine motif (amino acids 697-723) in the cytoplasmic C terminus of NHE5 that is recognized by β-arrestin2. Gross deletions of this site decreased the state of phosphorylation of NHE5 as well as its binding and responsiveness to β-arrestin2 in intact cells. More refined in vitro analyses showed that this site was robustly phosphorylated by the acidotropic protein kinase CK2, whereas other kinases, such as CK1 or the GPCR kinase GRK2, were considerably less potent. Simultaneous mutation of five Ser/Thr residues within 702-714 to Ala ((702)ST/AA(714)) abolished phosphorylation and binding of β-arrestin2. In transfected cells, the CK2 catalytic α subunit formed a complex with NHE5 and decreased wild-type but not (702)ST/AA(714) NHE5 activity, further supporting a regulatory role for this kinase. The rate of internalization of (702)ST/AA(714) was also diminished and relatively insensitive to overexpression of β-arrestin2. However, unlike in vitro, this mutant retained its ability to form a complex with β-arrestin2 despite its lack of responsiveness. Additional mutations of two di-isoleucine-based motifs (I697A/L698A and I722A/I723A) that immediately flank the acidic cluster, either separately or together, were required to disrupt their association. These data demonstrate that discrete elements of an elaborate sorting signal in NHE5 contribute to β-arrestin2 binding and trafficking along the recycling endosomal pathway.
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Gorini G, Ponomareva O, Shores KS, Person MD, Harris RA, Mayfield RD. Dynamin-1 co-associates with native mouse brain BKCa channels: proteomics analysis of synaptic protein complexes. FEBS Lett 2010; 584:845-51. [PMID: 20114047 DOI: 10.1016/j.febslet.2009.12.061] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 12/15/2009] [Accepted: 12/26/2009] [Indexed: 12/28/2022]
Abstract
In every synapse, a large number of proteins interact with other proteins in order to carry out signaling and transmission in the central nervous system. In this study, we used interaction proteomics to identify novel synaptic protein interactions in mouse cortical membranes under native conditions. Using immunoprecipitation, immunoblotting, and mass spectrometry, we identified a number of novel synaptic protein interactions involving soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), calcium-activated potassium channel (BKCa) alpha subunits, and dynamin-1. These novel interactions offer valuable insight into the protein-protein interaction network in intact synapses that could advance understanding of vesicle trafficking, release, and recycling.
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Affiliation(s)
- Giorgio Gorini
- Waggoner Center for Alcohol and Addiction Research, College of Natural Sciences, The University of Texas at Austin, Austin, TX 78712, USA.
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26
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Feliciangeli S, Tardy MP, Sandoz G, Chatelain FC, Warth R, Barhanin J, Bendahhou S, Lesage F. Potassium channel silencing by constitutive endocytosis and intracellular sequestration. J Biol Chem 2009; 285:4798-805. [PMID: 19959478 DOI: 10.1074/jbc.m109.078535] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Tandem of P domains in a weak inwardly rectifying K(+) channel 1 (TWIK1) is a K(+) channel that produces unusually low levels of current. Replacement of lysine 274 by a glutamic acid (K274E) is associated with stronger currents. This mutation would prevent conjugation of a small ubiquitin modifier peptide to Lys-274, a mechanism proposed to be responsible for channel silencing. However, we found no biochemical evidence of TWIK1 sumoylation, and we showed that the conservative change K274R did not increase current, suggesting that K274E modifies TWIK1 gating through a charge effect. Now we rule out an eventual effect of K274E on TWIK1 trafficking, and we provide convincing evidence that TWIK1 silencing results from its rapid retrieval from the cell surface. TWIK1 is internalized via a dynamin-dependent mechanism and addressed to the recycling endosomal compartment. Mutation of a diisoleucine repeat located in its cytoplasmic C terminus (I293A,I294A) stabilizes TWIK1 at the plasma membrane, resulting in robust currents. The effects of I293A,I294A on channel trafficking and of K274E on channel activity are cumulative, promoting even more currents. Activation of serotoninergic receptor 5-HT(1)R or adrenoreceptor alpha2A-AR stimulates TWIK1 but has no effect on TWIK1I293A,I294A, suggesting that G(i) protein activation is a physiological signal for increasing the number of active channels at the plasma membrane.
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Affiliation(s)
- Sylvain Feliciangeli
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, and Université de Nice Sophia-Antipolis, Sophia-Antipolis, 06560 Valbonne, France
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27
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Mykoniatis A, Shen L, Fedor-Chaiken M, Tang J, Tang X, Worrell RT, Delpire E, Turner JR, Matlin KS, Bouyer P, Matthews JB. Phorbol 12-myristate 13-acetate-induced endocytosis of the Na-K-2Cl cotransporter in MDCK cells is associated with a clathrin-dependent pathway. Am J Physiol Cell Physiol 2009; 298:C85-97. [PMID: 19864322 DOI: 10.1152/ajpcell.00118.2009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In secretory epithelial cells, the basolateral Na(+)-K(+)-2Cl(-) cotransporter (NKCC1) plays a major role in salt and fluid secretion. Our laboratory has identified NKCC1 surface expression as an important regulatory mechanism for Cl(-) secretion in the colonic crypt cell line T84, a process also present in native human colonic crypts. We previously showed that activation of protein kinase C (PKC) by carbachol and phorbol 12-myristate 13-acetate (PMA) decreases NKCC1 surface expression in T84 cells. However, the specific endocytic entry pathway has not been defined. We used a Madin-Darby canine kidney (MDCK) cell line stably transfected with enhanced green fluorescent protein (EGFP)-NKCC1 to map NKCC1 entry during PMA exposure. At given times, we fixed and stained the cells with specific markers (e.g., dynamin II, clathrin heavy chain, and caveolin-1). We also used chlorpromazine, methyl-beta-cyclodextrin, amiloride, and dynasore, blockers of the clathrin, caveolin, and macropinocytosis pathways and the vesicle "pinchase" dynamin, respectively. We found that PMA caused dose- and time-dependent NKCC1 endocytosis. After 2.5 min of PMA exposure, approximately 80% of EGFP-NKCC1 endocytic vesicles colocalized with clathrin and approximately 40% colocalized with dynamin II and with the transferrin receptor, the uptake of which is also mediated by clathrin-coated vesicles. We did not observe significant colocalization of EGFP-NKCC1 endocytic vesicles with caveolin-1, a marker of the caveolae-mediated endocytic pathway. We quantified the effect of each inhibitor on PMA-induced EGFP-NKCC1 endocytosis and found that only chlorpromazine and dynasore caused significant inhibition compared with the untreated control (61% and 25%, respectively, at 2.5 min). Together, these results strongly support the conclusion that PMA-stimulated NKCC1 endocytosis is associated with a clathrin pathway.
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Affiliation(s)
- Andreas Mykoniatis
- The Univ. of Chicago, 5841 S. Maryland Ave., MC 5029, Chicago, IL 60637, USA
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Fang L, Garuti R, Kim BY, Wade JB, Welling PA. The ARH adaptor protein regulates endocytosis of the ROMK potassium secretory channel in mouse kidney. J Clin Invest 2009; 119:3278-89. [PMID: 19841541 DOI: 10.1172/jci37950] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Accepted: 08/26/2009] [Indexed: 11/17/2022] Open
Abstract
Renal outer medullary potassium (ROMK) channels are exquisitely regulated to adjust renal potassium excretion and maintain potassium balance. Clathrin-dependent endocytosis plays a critical role, limiting urinary potassium loss in potassium deficiency. In renal disease, aberrant ROMK endocytosis may contribute to potassium retention and hyperkalemia. Previous work has indicated that ROMK endocytosis is stimulated by with-no-lysine (WNK) kinases, but the endocytotic signal and the internalization machinery have not been defined. Here, we found that ROMK bound directly to the clathrin adaptor molecule autosomal recessive hypercholesterolemia (ARH), and this interaction was mediated by what we believe to be a novel variant of the canonical "NPXY" endocytotic signal, YxNPxFV. ARH recruits ROMK to clathrin-coated pits for constitutive and WNK1-stimuated endocytosis, and ARH knockdown decreased basal rates of ROMK endocytosis, in a heterologous expression system, COS-7 cells. We found that ARH was predominantly expressed in the distal nephron where it coimmunoprecipitated and colocalized with ROMK. In mice, the abundance of kidney ARH protein was modulated by dietary potassium and inversely correlated with changes in ROMK. Furthermore, ARH-knockout mice exhibited an altered ROMK response to potassium intake. These data suggest that ARH marks ROMK for clathrin-dependent endocytosis, in concert with the demands of potassium homeostasis.
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Affiliation(s)
- Liang Fang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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29
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Tickets to ride: selecting cargo for clathrin-regulated internalization. Nat Rev Mol Cell Biol 2009; 10:583-96. [PMID: 19696796 DOI: 10.1038/nrm2751] [Citation(s) in RCA: 416] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Clathrin-mediated endocytosis oversees the constitutive packaging of selected membrane cargoes into transport vesicles that fuse with early endosomes. The process is responsive to activation of signalling receptors and ion channels, promptly clearing post-translationally tagged forms of cargo off the plasma membrane. To accommodate the diverse array of transmembrane proteins that are variably gathered into forming vesicles, a dedicated sorting machinery cooperates to ensure that non-competitive uptake from the cell surface occurs within minutes. Recent structural and functional data reveal remarkable plasticity in how disparate sorting signals are recognized by cargo-selective clathrin adaptors, such as AP-2. Cargo loading also seems to govern whether coats ultimately bud or dismantle abortively at the cell surface.
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Bernhardt U, Carlotti F, Hoeben RC, Joost HG, Al-Hasani H. A dual role of the N-terminal FQQI motif in GLUT4 trafficking. Biol Chem 2009; 390:883-92. [DOI: 10.1515/bc.2009.095] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
AbstractIn adipocytes, the glucose transporter GLUT4 recycles between intracellular storage vesicles and the plasma membrane. GLUT4 is internalized by a clathrin- and dynamin-dependent mechanism, and sorted into an insulin-sensitive storage compartment. Insulin stimulation leads to GLUT4 accumulation on the cell surface. The N-terminal F5QQI motif in GLUT4 has been shown previously to be required for sorting of the protein in the basal state. Here, we show that the FQQI motif is a binding site for the medium chain adaptin μ1, a subunit of the AP-1 adaptor complex that plays a role in post-Golgi/endosomal trafficking events. In order to investigate the role of AP-1 and AP-2 in GLUT4 trafficking, we generated 3T3-L1 adipocytes expressing HA-GLUT4-GFP and knocked down the AP-1 and AP-2 complex by RNAi, respectively. In AP-1 and AP-2 knockdown adipocytes, GLUT4 accumulates at the cell surface in the basal state, consistent with a role of AP-1 in post-endosomal sorting of GLUT4 to the insulin-sensitive storage compartment, and of AP-2 in clathrin-mediated endocytosis. Our data demonstrate a dual role of the F5QQI motif and support the conclusion that the AP complexes direct GLUT4 trafficking and endocytosis.
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Yan X, Zhou H, Zhang J, Shi C, Xie X, Wu Y, Tian C, Shen Y, Long J. Molecular mechanism of inward rectifier potassium channel 2.3 regulation by tax-interacting protein-1. J Mol Biol 2009; 392:967-76. [PMID: 19635485 DOI: 10.1016/j.jmb.2009.07.060] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 06/10/2009] [Accepted: 07/21/2009] [Indexed: 01/02/2023]
Abstract
Inwardly rectifying potassium channel 2.3 (Kir2.3) is specifically targeted on the basolateral membranes of epithelial and neuronal cells, and it thus plays an important role in maintaining potassium homeostasis. Tax-interacting protein-1 (TIP-1), an atypical PDZ-domain-containing protein, binds to Kir2.3 with a high affinity, causing the intracellular accumulation of Kir2.3 in cultured epithelial cells. However, the molecular basis of the TIP-1/Kir2.3 interaction is still poorly understood. Here, we present the crystal structure of TIP-1 in complex with the C-terminal Kir2.3-peptide (residues 436-445) to reveal the molecular details of the interaction between them. Moreover, isothermal titration calorimetry experiments show that the C-terminal Kir2.3-peptide binds much more strongly to TIP-1 than to mammalian Lin-7, indicating that TIP-1 can compete with mammalian Lin-7 to uncouple Kir2.3 from its basolateral membrane anchoring complex. We further show that the phosphorylation/dephosphorylation of Ser443 within the C-terminal Kir2.3 PDZ-binding motif RRESAI dynamically regulates the Kir2.3/TIP-1 association in heterologous HEK293T cells. These data suggest that TIP-1 may act as an important regulator for the endocytic pathway of Kir2.3.
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Affiliation(s)
- Xiaojie Yan
- Tianjin Key Laboratory of Protein Science, College of Life Science, Nankai University, Tianjin 300071, China
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32
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Subramanya AR, Liu J, Ellison DH, Wade JB, Welling PA. WNK4 diverts the thiazide-sensitive NaCl cotransporter to the lysosome and stimulates AP-3 interaction. J Biol Chem 2009; 284:18471-80. [PMID: 19401467 DOI: 10.1074/jbc.m109.008185] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
With-no-lysine kinase 4 (WNK4) inhibits electroneutral sodium chloride reabsorption by attenuating the cell surface expression of the thiazide-sensitive NaCl cotransporter (NCC). The underlying mechanism for this effect remains poorly understood. Here, we explore how WNK4 affects the trafficking of NCC through its interactions with intracellular sorting machinery. An analysis of NCC cell surface lifetime showed that WNK4 did not alter the net rate of cotransporter internalization. In contrast, direct measurements of forward trafficking revealed that WNK4 attenuated the rate of NCC surface delivery, inhibiting the anterograde movement of cotransporters traveling to the plasma membrane from the trans-Golgi network. The response was paralleled by a dramatic reduction in NCC protein abundance, an effect that was sensitive to the lysosomal protease inhibitor leupeptin, insensitive to proteasome inhibition, and attenuated by endogenous WNK4 knockdown. Subcellular localization studies performed in the presence of leupeptin revealed that WNK4 enhanced the accumulation of NCC in lysosomes. Moreover, NCC immunoprecipitated with endogenous AP-3 complexes, and WNK4 increased the fraction of cotransporters that associate with this adaptor, which facilitates cargo transport to lysosomes. WNK4 expression also increased LAMP-2-positive lysosomal content, indicating that the kinase may act by a general AP-3-dependent mechanism to promote cargo delivery into the lysosomal pathway. Taken together, these findings indicate that WNK4 inhibits NCC activity by diverting the cotransporter to the lysosome for degradation by way of an AP-3 transport carrier.
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Affiliation(s)
- Arohan R Subramanya
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
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