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Kutzsche J, Guzman GA, Willuweit A, Kletke O, Wollert E, Gering I, Jürgens D, Breitkreutz J, Stark H, Beck-Sickinger AG, Klöcker N, Hidalgo P, Willbold D. An orally available Ca v2.2 calcium channel inhibitor for the treatment of neuropathic pain. Br J Pharmacol 2024; 181:1734-1756. [PMID: 38157867 DOI: 10.1111/bph.16309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 11/29/2023] [Accepted: 12/14/2023] [Indexed: 01/03/2024] Open
Abstract
BACKGROUND AND PURPOSE Neuropathic pain affects up to 10% of the global population and is caused by an injury or a disease affecting the somatosensory, peripheral, or central nervous system. NP is characterized by chronic, severe and opioid-resistant properties. Therefore, its clinical management remains very challenging. The N-type voltage-gated calcium channel, Cav2.2, is a validated target for therapeutic intervention in chronic and neuropathic pain. The conotoxin ziconotide (Prialt®) is an FDA-approved drug that blocks Cav2.2 channel but needs to be administered intrathecally. Thus, although being principally efficient, the required application route is very much in disfavour. EXPERIMENTAL APPROACH AND KEY RESULTS Here, we describe an orally available drug candidate, RD2, which competes with ziconotide binding to Cav2.2 at nanomolar concentrations and inhibits Cav2.2 almost completely reversible. Other voltage-gated calcium channel subtypes, like Cav1.2 and Cav3.2, were affected by RD2 only at concentrations higher than 10 μM. Data from sciatic inflammatory neuritis rat model demonstrated the in vivo proof of concept, as low-dose RD2 (5 mg·kg-1) administered orally alleviated neuropathic pain compared with vehicle controls. High-dose RD2 (50 mg·kg-1) was necessary to reduce pain sensation in acute thermal response assessed by the tail flick test. CONCLUSIONS AND IMPLICATIONS Taken together, these results demonstrate that RD2 has antiallodynic properties. RD2 is orally available, which is the most convenient application form for patients and caregivers. The surprising and novel result from standard receptor screens opens the room for further optimization into new promising drug candidates, which address an unmet medical need.
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Affiliation(s)
- Janine Kutzsche
- Institute of Biological Information Processing 7, Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Gustavo A Guzman
- Institute of Biological Information Processing 7, Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Antje Willuweit
- Institute of Neuroscience and Medicine, Medical Imaging Physics, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Olaf Kletke
- Institute of Neuro- und Sensory Physiology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Esther Wollert
- Institute of Biological Information Processing 7, Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Ian Gering
- Institute of Biological Information Processing 7, Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Dagmar Jürgens
- Institute of Biological Information Processing 7, Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Jörg Breitkreutz
- Institute of Pharmaceutics and Biopharmaceutics, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Holger Stark
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | | | - Nikolaj Klöcker
- Institute of Pharmaceutics and Biopharmaceutics, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Patricia Hidalgo
- Institute of Biological Information Processing 1, Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Dieter Willbold
- Institute of Biological Information Processing 7, Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
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2
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Becic A, Leifeld J, Shaukat J, Hollmann M. Tetraspanins as Potential Modulators of Glutamatergic Synaptic Function. Front Mol Neurosci 2022; 14:801882. [PMID: 35046772 PMCID: PMC8761850 DOI: 10.3389/fnmol.2021.801882] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/07/2021] [Indexed: 12/16/2022] Open
Abstract
Tetraspanins (Tspans) comprise a membrane protein family structurally defined by four transmembrane domains and intracellular N and C termini that is found in almost all cell types and tissues of eukaryotes. Moreover, they are involved in a bewildering multitude of diverse biological processes such as cell adhesion, motility, protein trafficking, signaling, proliferation, and regulation of the immune system. Beside their physiological roles, they are linked to many pathophysiological phenomena, including tumor progression regulation, HIV-1 replication, diabetes, and hepatitis. Tetraspanins are involved in the formation of extensive protein networks, through interactions not only with themselves but also with numerous other specific proteins, including regulatory proteins in the central nervous system (CNS). Interestingly, recent studies showed that Tspan7 impacts dendritic spine formation, glutamatergic synaptic transmission and plasticity, and that Tspan6 is correlated with epilepsy and intellectual disability (formerly known as mental retardation), highlighting the importance of particular tetraspanins and their involvement in critical processes in the CNS. In this review, we summarize the current knowledge of tetraspanin functions in the brain, with a particular focus on their impact on glutamatergic neurotransmission. In addition, we compare available resolved structures of tetraspanin family members to those of auxiliary proteins of glutamate receptors that are known for their modulatory effects.
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Identification of Toxocara canis Antigen-Interacting Partners by Yeast Two-Hybrid Assay and a Putative Mechanism of These Host-Parasite Interactions. Pathogens 2021; 10:pathogens10080949. [PMID: 34451413 PMCID: PMC8398310 DOI: 10.3390/pathogens10080949] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/23/2021] [Accepted: 07/25/2021] [Indexed: 01/11/2023] Open
Abstract
Toxocara canis is a zoonotic roundworm that infects humans and dogs all over the world. Upon infection, larvae migrate to various tissues leading to different clinical syndromes. The host–parasite interactions underlying the process of infection remain poorly understood. Here, we describe the application of a yeast two-hybrid assay to screen a human cDNA library and analyse the interactome of T. canis larval molecules. Our data identifies 16 human proteins that putatively interact with the parasite. These molecules were associated with major biological processes, such as protein processing, transport, cellular component organisation, immune response and cell signalling. Some of these identified interactions are associated with the development of a Th2 response, neutrophil activity and signalling in immune cells. Other interactions may be linked to neurodegenerative processes observed during neurotoxocariasis, and some are associated with lung pathology found in infected hosts. Our results should open new areas of research and provide further data to enable a better understanding of this complex and underestimated disease.
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Murru L, Ponzoni L, Longatti A, Mazzoleni S, Giansante G, Bassani S, Sala M, Passafaro M. Lateral habenula dysfunctions in Tm4sf2 -/y mice model for neurodevelopmental disorder. Neurobiol Dis 2021; 148:105189. [PMID: 33227491 PMCID: PMC7840593 DOI: 10.1016/j.nbd.2020.105189] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/30/2020] [Accepted: 11/17/2020] [Indexed: 12/25/2022] Open
Abstract
Mutations in the TM4SF2 gene, which encodes TSPAN7, cause a severe form of intellectual disability (ID) often comorbid with autism spectrum disorder (ASD). Recently, we found that TM4SF2 loss in mice affects cognition. Here, we report that Tm4sf2-/y mice, beyond an ID-like phenotype, display altered sociability, increased repetitive behaviors, anhedonic- and depressive-like states. Cognition relies on the integration of information from several brain areas. In this context, the lateral habenula (LHb) is strategically positioned to coordinate the brain regions involved in higher cognitive functions. Furthermore, in Tm4sf2-/y mice we found that LHb neurons present hypoexcitability, aberrant neuronal firing pattern and altered sodium and potassium voltage-gated ion channels function. Interestingly, we also found a reduced expression of voltage-gated sodium channel and a hyperactivity of the PKC-ERK pathway, a well-known modulator of ion channels activity, which might explain the functional phenotype showed by Tm4sf2-/y mice LHb neurons. These findings support Tm4sf2-/y mice as useful in modeling some ASD-like symptoms. Additionally, we can speculate that LHb functional alteration in Tm4sf2-/y mice might play a role in the disease pathophysiology.
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Affiliation(s)
- Luca Murru
- Institute of Neuroscience, CNR, Milan 20129, Italy; NeuroMI Milan Center for Neuroscience, Università Milano-Bicocca, Milan 20126, Italy.
| | - Luisa Ponzoni
- Department of Medical Biotechnology and Translational Medicine, Università di Milano, Segrate, MI 20090, Italy
| | | | - Sara Mazzoleni
- Institute of Neuroscience, CNR, Milan 20129, Italy; Department of Medical Biotechnology and Translational Medicine, Università di Milano, Segrate, MI 20090, Italy
| | | | - Silvia Bassani
- Institute of Neuroscience, CNR, Milan 20129, Italy; NeuroMI Milan Center for Neuroscience, Università Milano-Bicocca, Milan 20126, Italy
| | - Mariaelvina Sala
- Institute of Neuroscience, CNR, Milan 20129, Italy; NeuroMI Milan Center for Neuroscience, Università Milano-Bicocca, Milan 20126, Italy
| | - Maria Passafaro
- Institute of Neuroscience, CNR, Milan 20129, Italy; NeuroMI Milan Center for Neuroscience, Università Milano-Bicocca, Milan 20126, Italy.
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5
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Helassa N. TSPAN-7 as a key regulator of glucose-stimulated Ca 2+ influx and insulin secretion. J Physiol 2020; 599:1733-1734. [PMID: 33347614 DOI: 10.1113/jp281053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 12/08/2020] [Indexed: 11/08/2022] Open
Affiliation(s)
- Nordine Helassa
- Liverpool Centre for Cardiovascular Science, Department of Cardiovascular Science and Metabolic Medicine, Institute of Life Course and Medical Sciences, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, L69 3BX, UK
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6
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Dickerson MT, Dadi PK, Butterworth RB, Nakhe AY, Graff SM, Zaborska KE, Schaub CM, Jacobson DA. Tetraspanin-7 regulation of L-type voltage-dependent calcium channels controls pancreatic β-cell insulin secretion. J Physiol 2020; 598:4887-4905. [PMID: 32790176 PMCID: PMC8095317 DOI: 10.1113/jp279941] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/20/2020] [Indexed: 12/20/2022] Open
Abstract
KEY POINTS Tetraspanin (TSPAN) proteins regulate many biological processes, including intracellular calcium (Ca2+ ) handling. TSPAN-7 is enriched in pancreatic islet cells; however, the function of islet TSPAN-7 has not been identified. Here, we characterize how β-cell TSPAN-7 regulates Ca2+ handling and hormone secretion. We find that TSPAN-7 reduces β-cell glucose-stimulated Ca2+ entry, slows Ca2+ oscillation frequency and decreases glucose-stimulated insulin secretion. TSPAN-7 controls β-cell function through a direct interaction with L-type voltage-dependent Ca2+ channels (CaV 1.2 and CaV 1.3), which reduces channel Ca2+ conductance. TSPAN-7 slows activation of CaV 1.2 and accelerates recovery from voltage-dependent inactivation; TSPAN-7 also slows CaV 1.3 inactivation kinetics. These findings strongly implicate TSPAN-7 as a key regulator in determining the set-point of glucose-stimulated Ca2+ influx and insulin secretion. ABSTRACT Glucose-stimulated insulin secretion (GSIS) is regulated by calcium (Ca2+ ) entry into pancreatic β-cells through voltage-dependent Ca2+ (CaV ) channels. Tetraspanin (TSPAN) transmembrane proteins control Ca2+ handling, and thus they may also modulate GSIS. TSPAN-7 is the most abundant islet TSPAN and immunostaining of mouse and human pancreatic slices shows that TSPAN-7 is highly expressed in β- and α-cells; however, the function of islet TSPAN-7 has not been determined. Here, we show that TSPAN-7 knockdown (KD) increases glucose-stimulated Ca2+ influx into mouse and human β-cells. Additionally, mouse β-cell Ca2+ oscillation frequency was accelerated by TSPAN-7 KD. Because TSPAN-7 KD also enhanced Ca2+ entry when membrane potential was clamped with depolarization, the effect of TSPAN-7 on CaV channel activity was examined. TSPAN-7 KD enhanced L-type CaV currents in mouse and human β-cells. Conversely, heterologous expression of TSPAN-7 with CaV 1.2 and CaV 1.3 L-type CaV channels decreased CaV currents and reduced Ca2+ influx through both channels. This was presumably the result of a direct interaction of TSPAN-7 and L-type CaV channels because TSPAN-7 coimmunoprecipitated with both CaV 1.2 and CaV 1.3 from primary human β-cells and from a heterologous expression system. Finally, TSPAN-7 KD in human β-cells increased basal (5.6 mM glucose) and stimulated (45 mM KCl + 14 mM glucose) insulin secretion. These findings strongly suggest that TSPAN-7 modulation of β-cell L-type CaV channels is a key determinant of β-cell glucose-stimulated Ca2+ entry and thus the set-point of GSIS.
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Affiliation(s)
- Matthew T Dickerson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, 7425B MRB IV, Nashville, TN, USA
| | - Prasanna K Dadi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, 7425B MRB IV, Nashville, TN, USA
| | - Regan B Butterworth
- Department of Molecular Physiology and Biophysics, Vanderbilt University, 7425B MRB IV, Nashville, TN, USA
| | - Arya Y Nakhe
- Department of Molecular Physiology and Biophysics, Vanderbilt University, 7425B MRB IV, Nashville, TN, USA
| | - Sarah M Graff
- Department of Molecular Physiology and Biophysics, Vanderbilt University, 7425B MRB IV, Nashville, TN, USA
| | - Karolina E Zaborska
- Department of Molecular Physiology and Biophysics, Vanderbilt University, 7425B MRB IV, Nashville, TN, USA
| | - Charles M Schaub
- Department of Molecular Physiology and Biophysics, Vanderbilt University, 7425B MRB IV, Nashville, TN, USA
| | - David A Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, 7425B MRB IV, Nashville, TN, USA
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7
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Lacinova L, Mallmann RT, Jurkovičová-Tarabová B, Klugbauer N. Modulation of voltage-gated Ca V2.2 Ca 2+ channels by newly identified interaction partners. Channels (Austin) 2020; 14:380-392. [PMID: 33006503 PMCID: PMC7567506 DOI: 10.1080/19336950.2020.1831328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Voltage-gated Ca2+ channels are typically integrated in a complex network of protein-protein-interactions, also referred to as Ca2+ channel nanodomains. Amongst the neuronal CaV2 channel family, CaV2.2 is of particular importance due to its general role for signal transmission from the periphery to the central nervous system, but also due to its significance for pain perception. Thus, CaV2.2 is an ideal target candidate to search for pharmacological inhibitors but also for novel modulatory interactors. In this review we summarize the last years findings of our intense screenings and characterization of the six CaV2.2 interaction partners, tetraspanin-13 (TSPAN-13), reticulon 1 (RTN1), member 1 of solute carrier family 38 (SLC38), prostaglandin D2 synthase (PTGDS), transmembrane protein 223 (TMEM223), and transmembrane BAX inhibitor motif 3 (Grina/TMBIM3) containing protein. Each protein shows a unique way of channel modulation as shown by extensive electrophysiological studies. Amongst the newly identified interactors, Grina/TMBIM3 is most striking due to its modulatory effect which is rather comparable to G-protein regulation.
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Affiliation(s)
- Lubica Lacinova
- Center of Bioscience, - Institute for Molecular Physiology and Genetics , Bratislava, Slovakia.,Faculty of Natural Sciences, University of Ss. Cyril and Methodius , Trnava, Slovakia
| | - Robert Theodor Mallmann
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Fakultät für Medizin, Albert-Ludwigs-Universität Freiburg , Freiburg, Germany
| | | | - Norbert Klugbauer
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Fakultät für Medizin, Albert-Ludwigs-Universität Freiburg , Freiburg, Germany.,Center for Basics in NeuroModulation (Neuromodul Basics), Albert-Ludwigs-Universität Freiburg , Freiburg, Germany
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8
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A potential role for T-type calcium channels in homocysteinemia-induced peripheral neuropathy. Pain 2019; 160:2798-2810. [DOI: 10.1097/j.pain.0000000000001669] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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9
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Grina/TMBIM3 modulates voltage-gated Ca V2.2 Ca 2+ channels in a G-protein-like manner. Cell Calcium 2019; 80:71-78. [PMID: 30991297 DOI: 10.1016/j.ceca.2019.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/01/2019] [Accepted: 04/07/2019] [Indexed: 11/21/2022]
Abstract
Grina/TMBIM3 is a poorly characterized transmembrane protein with a broad expression pattern in mammals and with a very ancient origin within eukaryotes. Although initially characterized as an NMDA-receptor associated subunit, there is increasing evidence that Grina/TMBIM3 is involved in the unfolded protein response and controls apoptosis via regulation of Ca2+ homeostasis. Here, we investigate a putative direct interaction of Grina/TMBIM3 with voltage gated Ca2+ channels, in particular with the CaV2.2 α1-subunit and describe its modulatory effects on the current through CaV2.2 N-type channels. Direct interaction was confirmed by co-immunoprecipitation studies and membrane localization was proven. Co-expression of Grina/TMBIM3 with CaV2.2 channels resulted in a significant decrease of the current amplitude and in a slowing of the kinetics of current activation. This effect was accompanied by a significant shift of the voltage dependencies of activation time constants towards more depolarized voltages. Application of a stimulus protocol including a strong depolarizing pulse relieved inhibition of current amplitude by Grina/TMBIM3. When Grina/TMBIM3 was present, inactivation by an action potential-like train of pulses was diminished. Both observations resemble mechanisms that are well-studied modulatory effects of G-protein βγ subunits on CaV2 channels. The impact of Grina/TMBIM3 and G-protein βγ subunits are rather comparable with respect to suppression of current amplitude and slowing of activation kinetics. Furthermore, both modulators had the same effect on current inactivation when evoked by an action potential-like train of pulses.
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10
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Haghir S, Alemzadeh A. Cloning and molecular characterization of TaERF6, a gene encoding a bread wheat ethylene response factor. MOLECULAR BIOLOGY RESEARCH COMMUNICATIONS 2019; 7:153-163. [PMID: 30788378 PMCID: PMC6363940 DOI: 10.22099/mbrc.2018.30339.1336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ethylene response factor proteins are important for regulating gene expression under different stresses. Different isoforms for ERF have previously isolated from bread wheat (Triticum aestivum L.) and related genera and called from TaERF1 to TaERF5. We isolated, cloned and molecular characterized a novel one based on TdERF1, an isoform in durum wheat (Triticum turgidum L.) and called TaERF6. Its cDNA was synthesized, sequenced and compared with genomic sequence to figure out intron and exon regions and determine coding sequence region. The length of TdERF1 gene was 1939 bp and cDNA was 1065 bp including two exons, the first one 259 bp and the second one 806 bp separated by a 874 bp intron with a 111 bp 5'-UTR (untranslated region) and 401 bp 3'-UTR. TaERF6 encodes a 353 amino acids protein with nearly 99% identity to TdERF1. Hydrophobic cluster analysis revealed an N-terminal hydrophobic domain contains a highly conserved motif with the consensus sequence of M [C/L/Y] [G/R] [G/R/P] [A/G/V/L/R] [I/L/R/S/P/Q] [L/I/R/H] and hydrophobic clusters in AP2/ERF domain of which tends to form -sheet. Three monopartite nuclear localization signals also identified in TaERF6 that play important role in getting back into the nucleus. The results showed several putative phosphorylation sites in TaERF6 that a motif from residues 246 to 266, the CMVII-4 motif, was predicted to phosphorylate by different kinase proteins and play important roles in TaERF6 function. Phylogenetic analysis showed 7 clusters (I to VII) and 10 subclusters according to their relatedness in Poaceae family.
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Affiliation(s)
- Shahrzad Haghir
- Department of Crop Production and Plant Breeding, School of Agriculture, Shiraz University, Shiraz, Iran
| | - Abbas Alemzadeh
- Department of Crop Production and Plant Breeding, School of Agriculture, Shiraz University, Shiraz, Iran
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Mallmann R, Ondacova K, Moravcikova L, Jurkovicova-Tarabova B, Pavlovicova M, Moravcik R, Lichvarova L, Kominkova V, Klugbauer N, Lacinova L. Four novel interaction partners demonstrate diverse modulatory effects on voltage-gated Ca V2.2 Ca 2+ channels. Pflugers Arch 2019; 471:861-874. [PMID: 30612149 DOI: 10.1007/s00424-018-02248-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 12/14/2018] [Accepted: 12/18/2018] [Indexed: 12/11/2022]
Abstract
Voltage-gated Ca2+ channels are embedded in a network of protein interactions that are fundamental for channel function and modulation. Different strategies such as high-resolution quantitative MS analyses and yeast-two hybrid screens have been used to uncover these Ca2+ channel nanodomains. We applied the yeast split-ubiquitin system with its specific advantages to search for interaction partners of the CaV2.2 Ca2+ channel and identified four proteins: reticulon 1 (RTN1), member 1 of solute carrier family 38 (SLC38), prostaglandin D2 synthase (PTGDS) and transmembrane protein 223 (TMEM223). Interactions were verified using the yeast split-ubiquitin system and narrowed down to CaV2.2 domain IV. Colocalization studies using fluorescent constructs demonstrated defined regions of subcellular localization. Detailed electrophysiological studies revealed that coexpression of RTN1 modulated CaV2.2 channels only to a minor extent. SLC38 accelerated the cumulative current inactivation during a high-frequency train of brief depolarizing pulses. As neurons expressing CaV2.2 channels were exposed to high-frequency bursts under physiological conditions, observed regulation may have a negative modulatory effect on transmitter release. Coexpression of PTGDS significantly lowered the average current density and slowed the kinetics of cumulative current inactivation. Since the latter effect was not significant, it may only partly compensate the first one under physiological conditions. Expression of TMEM223 lowered the average current density, accelerated the kinetics of cumulative current inactivation and slowed the kinetics of recovery from inactivation. Therefore, TMEM223 and, to a lesser extent, PTGDS, may negatively modulate Ca2+ entry required for transmitter release and/or for dendritic plasticity under physiological conditions.
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Affiliation(s)
- Robert Mallmann
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Fakultät für Medizin, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104, Freiburg, Germany
| | - Katarina Ondacova
- Center of Bioscience, Institute for Molecular Physiology and Genetics, 84005, Bratislava, Slovakia
| | - Lucia Moravcikova
- Center of Bioscience, Institute for Molecular Physiology and Genetics, 84005, Bratislava, Slovakia
| | | | - Michaela Pavlovicova
- Center of Bioscience, Institute for Molecular Physiology and Genetics, 84005, Bratislava, Slovakia
| | - Roman Moravcik
- Center of Bioscience, Institute for Molecular Physiology and Genetics, 84005, Bratislava, Slovakia
| | - Lucia Lichvarova
- Center of Bioscience, Institute for Molecular Physiology and Genetics, 84005, Bratislava, Slovakia
| | - Viera Kominkova
- Center of Bioscience, Institute for Molecular Physiology and Genetics, 84005, Bratislava, Slovakia
| | - Norbert Klugbauer
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Fakultät für Medizin, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104, Freiburg, Germany
| | - Lubica Lacinova
- Center of Bioscience, Institute for Molecular Physiology and Genetics, 84005, Bratislava, Slovakia.
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12
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Castonguay J, Orth JHC, Müller T, Sleman F, Grimm C, Wahl-Schott C, Biel M, Mallmann RT, Bildl W, Schulte U, Klugbauer N. The two-pore channel TPC1 is required for efficient protein processing through early and recycling endosomes. Sci Rep 2017; 7:10038. [PMID: 28855648 PMCID: PMC5577145 DOI: 10.1038/s41598-017-10607-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/11/2017] [Indexed: 02/06/2023] Open
Abstract
Two-pore channels (TPCs) are localized in endo-lysosomal compartments and assumed to play an important role for vesicular fusion and endosomal trafficking. Recently, it has been shown that both TPC1 and 2 were required for host cell entry and pathogenicity of Ebola viruses. Here, we investigate the cellular function of TPC1 using protein toxins as model substrates for distinct endosomal processing routes. Toxin uptake and activation through early endosomes but not processing through other compartments were reduced in TPC1 knockout cells. Detailed co-localization studies with subcellular markers confirmed predominant localization of TPC1 to early and recycling endosomes. Proteomic analysis of native TPC1 channels finally identified direct interaction with a distinct set of syntaxins involved in fusion of intracellular vesicles. Together, our results demonstrate a general role of TPC1 for uptake and processing of proteins in early and recycling endosomes, likely by providing high local Ca2+ concentrations required for SNARE-mediated vesicle fusion.
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Affiliation(s)
- Jan Castonguay
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany
| | - Joachim H C Orth
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany
| | - Thomas Müller
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany
| | - Faten Sleman
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany
| | - Christian Grimm
- Department of Pharmacy, Center for Drug Research and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-University, Munich, Germany
| | - Christian Wahl-Schott
- Department of Pharmacy, Center for Drug Research and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-University, Munich, Germany
| | - Martin Biel
- Department of Pharmacy, Center for Drug Research and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-University, Munich, Germany
| | - Robert Theodor Mallmann
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany
| | - Wolfgang Bildl
- Institute of Physiology II, Faculty of Medicine, Albert-Ludwigs-University, Hermann-Herder-Strasse 7, 79104, Freiburg, Germany
| | - Uwe Schulte
- Institute of Physiology II, Faculty of Medicine, Albert-Ludwigs-University, Hermann-Herder-Strasse 7, 79104, Freiburg, Germany.,Logopharm GmbH, Schlossstrasse 14, 79232, March-Buchheim, Germany.,Center for Biological Signaling Studies (BIOSS), Schänzlestrasse 18, 79104, Freiburg, Germany
| | - Norbert Klugbauer
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany.
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Rivas-Ramirez P, Gadotti VM, Zamponi GW, Weiss N. Surfen is a broad-spectrum calcium channel inhibitor with analgesic properties in mouse models of acute and chronic inflammatory pain. Pflugers Arch 2017; 469:1325-1334. [DOI: 10.1007/s00424-017-2017-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/12/2017] [Accepted: 06/13/2017] [Indexed: 01/09/2023]
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