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Zhang H, Yin YL, Dai A, Zhang T, Zhang C, Wu C, Hu W, He X, Pan B, Jin S, Yuan Q, Wang MW, Yang D, Xu HE, Jiang Y. Dimerization and antidepressant recognition at noradrenaline transporter. Nature 2024; 630:247-254. [PMID: 38750358 DOI: 10.1038/s41586-024-07437-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 04/17/2024] [Indexed: 06/07/2024]
Abstract
The noradrenaline transporter has a pivotal role in regulating neurotransmitter balance and is crucial for normal physiology and neurobiology1. Dysfunction of noradrenaline transporter has been implicated in numerous neuropsychiatric diseases, including depression and attention deficit hyperactivity disorder2. Here we report cryo-electron microscopy structures of noradrenaline transporter in apo and substrate-bound forms, and as complexes with six antidepressants. The structures reveal a noradrenaline transporter dimer interface that is mediated predominantly by cholesterol and lipid molecules. The substrate noradrenaline binds deep in the central binding pocket, and its amine group interacts with a conserved aspartate residue. Our structures also provide insight into antidepressant recognition and monoamine transporter selectivity. Together, these findings advance our understanding of noradrenaline transporter regulation and inhibition, and provide templates for designing improved antidepressants to treat neuropsychiatric disorders.
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Affiliation(s)
- Heng Zhang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | | | - Antao Dai
- State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Tianwei Zhang
- Lingang Laboratory, Shanghai, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Chao Zhang
- National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- School of Pharmacy, Fudan University, Shanghai, China
| | - Canrong Wu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Wen Hu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- Shanghai Advanced Electron Microscope Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xinheng He
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | | | | | - Qingning Yuan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- Shanghai Advanced Electron Microscope Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ming-Wei Wang
- Research Center for Deepsea Bioresources, Sanya, China
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, China
- School of Pharmacy, Hainan Medical University, Haikou, China
| | - Dehua Yang
- State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - H Eric Xu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
- Shanghai Advanced Electron Microscope Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
| | - Yi Jiang
- Lingang Laboratory, Shanghai, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
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2
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Gou R, Yang J, Guo M, Chen Y, Xue W. CNSMolGen: A Bidirectional Recurrent Neural Network-Based Generative Model for De Novo Central Nervous System Drug Design. J Chem Inf Model 2024; 64:4059-4070. [PMID: 38739718 DOI: 10.1021/acs.jcim.4c00504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Central nervous system (CNS) drugs have had a significant impact on treating a wide range of neurodegenerative and psychiatric disorders. In recent years, deep learning-based generative models have shown great potential for accelerating drug discovery and improving efficacy. However, specific applications of these techniques in CNS drug discovery have not been widely reported. In this study, we developed the CNSMolGen model, which uses a framework of bidirectional recurrent neural networks (Bi-RNNs) for de novo molecular design of CNS drugs. Results showed that the pretrained model was able to generate more than 90% of completely new molecular structures, which possessed the properties of CNS drug molecules and were synthesizable. In addition, transfer learning was performed on small data sets with specific biological activities to evaluate the potential application of the model for CNS drug optimization. Here, we used drugs against the classical CNS disease target serotonin transporter (SERT) as a fine-tuned data set and generated a focused database against the target protein. The potential biological activities of the generated molecules were verified by using the physics-based induced-fit docking study. The success of this model demonstrates its potential in CNS drug design and optimization, which provides a new impetus for future CNS drug development.
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Affiliation(s)
- Rongpei Gou
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Jingyi Yang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Menghan Guo
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Yingjun Chen
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Weiwei Xue
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
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Zhang F, Chen B, Ren W, Yan Y, Zheng X, Jin S, Chang Y. Association analysis of dopaminergic degeneration and the neutrophil-to-lymphocyte ratio in Parkinson's disease. Front Aging Neurosci 2024; 16:1377994. [PMID: 38650864 PMCID: PMC11033456 DOI: 10.3389/fnagi.2024.1377994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 03/28/2024] [Indexed: 04/25/2024] Open
Abstract
Introduction Peripheral inflammatory responses are suggested to play a major role in the pathophysiology of Parkinson's disease (PD). The neutrophil-to-lymphocyte ratio (NLR), a new recognized biomarker, can reflect peripheral inflammation in PD. However, the association between the NLR and dopaminergic degeneration in PD remains unclear. Methods In this retrospective study, 101 enrolled PD patients were categorized into early-stage and advanced-stage PD based on the Hoehn and Yahr (HY) scale. We evaluated the clinical characteristics, peripheral immune profile, and 11C-CFT striatal dopamine transporter (DAT) binding levels. Linear regression analyses were employed to assess the associations between NLR and striatal DAT levels at different stages in PD patients. Results Covariate-controlled regression analysis revealed that higher NLR was significantly associated with lower DAT levels in the caudate (β = -0.27, p = 0.003) and the putamen (β = -0.27, p = 0.011). Moreover, in the early-stage PD subgroup, a similar association was observed (caudate: β = -0.37, p = 0.013; putamen: β = -0.45, p = 0.005). The lymphocytes count was correlated positively with the striatal DAT levels in the Spearman correlation analysis whether in total patients (caudate: ρ = 0.25, p = 0.013; putamen: ρ = 0.22, p = 0.026) or in the early-stage subgroup (caudate: ρ = 0.31, p = 0.023, putamen: ρ = 0.34, p = 0.011). Conclusion Dopaminergic degeneration is associated with peripheral inflammation in PD. The NLR, a widely used inflammatory marker, may have the potential to reflect the degree of dopaminergic degeneration in individuals with early-stage PD.
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Affiliation(s)
- Fengjiao Zhang
- Departments of Neurology, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Bin Chen
- Departments of Nuclear Medicine, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Wenhua Ren
- Departments of Neurology, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Yayun Yan
- Departments of Neurology, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Xiaoqi Zheng
- Departments of Neurology, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Shuxian Jin
- Departments of Neurology, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Ying Chang
- Departments of Neurology, China-Japan Union Hospital, Jilin University, Changchun, China
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4
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Chen S, Huang X, Zhang X, Li C, Zhang YW. A Conserved Intramolecular Ion-Pair Plays a Critical but Divergent Role in Regulation of Dimerization and Transport Function among the Monoamine Transporters. Int J Mol Sci 2024; 25:4032. [PMID: 38612840 PMCID: PMC11011927 DOI: 10.3390/ijms25074032] [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: 01/30/2024] [Revised: 03/26/2024] [Accepted: 04/02/2024] [Indexed: 04/14/2024] Open
Abstract
The monoamine transporters, including the serotonin transporter (SERT), dopamine transporter (DAT), and norepinephrine transporter (NET), are the therapeutic targets for the treatment of many neuropsychiatric disorders. Despite significant progress in characterizing the structures and transport mechanisms of these transporters, the regulation of their transport functions through dimerization or oligomerization remains to be understood. In the present study, we identified a conserved intramolecular ion-pair at the third extracellular loop (EL3) connecting TM5 and TM6 that plays a critical but divergent role in the modulation of dimerization and transport functions among the monoamine transporters. The disruption of the ion-pair interactions by mutations induced a significant spontaneous cross-linking of a cysteine mutant of SERT and an increase in cell surface expression but with an impaired specific transport activity. On the other hand, similar mutations of the corresponding ion-pair residues in both DAT and NET resulted in an opposite effect on their oxidation-induced dimerization, cell surface expression, and transport function. Reversible biotinylation experiments indicated that the ion-pair mutations slowed down the internalization of SERT but stimulated the internalization of DAT. In addition, cysteine accessibility measurements for monitoring SERT conformational changes indicated that substitution of the ion-pair residues resulted in profound effects on the rate constants for cysteine modification in both the extracellular and cytoplasmatic substrate permeation pathways. Furthermore, molecular dynamics simulations showed that the ion-pair mutations increased the interfacial interactions in a SERT dimer but decreased it in a DAT dimer. Taken together, we propose that the transport function is modulated by the equilibrium between monomers and dimers on the cell surface, which is regulated by a potential compensatory mechanism but with different molecular solutions among the monoamine transporters. The present study provided new insights into the structural elements regulating the transport function of the monoamine transporters through their dimerization.
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Affiliation(s)
| | | | | | | | - Yuan-Wei Zhang
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China; (S.C.); (X.H.); (X.Z.); (C.L.)
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5
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Karagöl T, Karagöl A, Zhang S. Structural bioinformatics studies of serotonin, dopamine and norepinephrine transporters and their AlphaFold2 predicted water-soluble QTY variants and uncovering the natural mutations of L->Q, I->T, F->Y and Q->L, T->I and Y->F. PLoS One 2024; 19:e0300340. [PMID: 38517879 PMCID: PMC10959339 DOI: 10.1371/journal.pone.0300340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 02/26/2024] [Indexed: 03/24/2024] Open
Abstract
Monoamine transporters including transporters for serotonin, dopamine, and norepinephrine play key roles in monoaminergic synaptic signaling, involving in the molecular etiology of a wide range of neurological and physiological disorders. Despite being crucial drug targets, the study of transmembrane proteins remains challenging due to their localization within the cell membrane. To address this, we present the structural bioinformatics studies of 7 monoamine transporters and their water-soluble variants designed using the QTY code, by systematically replacing the hydrophobic amino acids leucine (L), valine (V), isoleucine (I) and phenylalanine (F) with hydrophilic amino acids (glutamine (Q), threonine (T) and tyrosine (Y). The resulting QTY variants, despite significant protein transmembrane sequence differences (44.27%-51.85%), showed similar isoelectric points (pI) and molecular weights. While their hydrophobic surfaces significantly reduced, this change resulted in a minimal structural alteration. Quantitatively, Alphafold2 predicted QTY variant structures displayed remarkable similarity with RMSD 0.492Å-1.619Å. Accompanied by the structural similarities of substituted amino acids in the context of 1.5Å electron density maps, our study revealed multiple QTY and reverse QTY variations in genomic databases. We further analyzed their phenotypical and topological characteristics. By extending evolutionary game theory to the molecular foundations of biology, we provided insights into the evolutionary dynamics of chemically distinct alpha-helices, their usage in different chemotherapeutic applications, and open possibilities of diagnostic medicine. Our study rationalizes that QTY variants of monoamine transporters may not only become distinct tools for medical, structural, and evolutionary research, but these transporters may also emerge as contemporary therapeutic targets, providing a new approach to treatment for several conditions.
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Affiliation(s)
- Taner Karagöl
- Istanbul University Istanbul Medical Faculty, Istanbul, Turkey
| | - Alper Karagöl
- Istanbul University Istanbul Medical Faculty, Istanbul, Turkey
| | - Shuguang Zhang
- Laboratory of Molecular Architecture, Media Lab, Massachusetts Institute of Technology, Cambridge, MA, United States of America
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6
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Nguyen H, Cheng MH, Lee JY, Aggarwal S, Mortensen OV, Bahar I. Allosteric modulation of serotonin and dopamine transporters: New insights from computations and experiments. Curr Res Physiol 2024; 7:100125. [PMID: 38836245 PMCID: PMC11148570 DOI: 10.1016/j.crphys.2024.100125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 06/06/2024] Open
Abstract
Human monoamine transporters (MATs) are critical to regulating monoaminergic neurotransmission by translocating their substrates from the synaptic space back into the presynaptic neurons. As such, their primary substrate binding site S1 has been targeted by a wide range of compounds for treating neuropsychiatric and neurodegenerative disorders including depression, ADHD, neuropathic pain, and anxiety disorders. We present here a comparative study of the structural dynamics and ligand-binding properties of two MATs, dopamine transporter (DAT) and serotonin transporter (SERT), with focus on the allosteric modulation of their transport function by drugs or substrates that consistently bind a secondary site S2, proposed to serve as an allosteric site. Our systematic analysis of the conformational space and dynamics of a dataset of 50 structures resolved for DAT and SERT in the presence of one or more ligands/drugs reveals the specific residues playing a consistent role in coordinating the small molecules bound to subsites S2-I and S2-II within S2, such as R476 and Y481 in dDAT and E494, P561, and F556 in hSERT. Further analysis reveals how DAT and SERT differ in their two principal modes of structural changes, PC1 and PC2. Notably, PC1 underlies the transition between outward- and inward-facing states of the transporters as well as their gating; whereas PC2 supports the rearrangements of TM helices near the S2 site. Finally, the examination of cross-correlations between structural elements lining the respective sites S1 and S2 point to the crucial role of coupled motions between TM6a and TM10. In particular, we note the involvement of hSERT residues F335 and G338, and E493-E494-T497 belonging to these two respective helices, in establishing the allosteric communication between S1 and S2. These results help understand the molecular basis of the action of drugs that bind to the S2 site of DAT or SERT. They also provide a basis for designing allosteric modulators that may provide better control of specific interactions and cellular pathways, rather than indiscriminately inhibiting the transporter by targeting its orthosteric site.
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Affiliation(s)
- Hoang Nguyen
- Laufer Center for Physical and Quantitative Biology and, USA
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, 11794, USA
| | | | - Ji Young Lee
- Laufer Center for Physical and Quantitative Biology and, USA
| | - Shaili Aggarwal
- Department of Pharmacology and Physiology, Drexel University School of Medicine, Philadelphia, PA, 19102, USA
| | - Ole Valente Mortensen
- Department of Pharmacology and Physiology, Drexel University School of Medicine, Philadelphia, PA, 19102, USA
| | - Ivet Bahar
- Laufer Center for Physical and Quantitative Biology and, USA
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, 11794, USA
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7
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Guimaraes EL, Dias DO, Hau WF, Julien A, Holl D, Garcia-Collado M, Savant S, Vågesjö E, Phillipson M, Jakobsson L, Göritz C. Corpora cavernosa fibroblasts mediate penile erection. Science 2024; 383:eade8064. [PMID: 38330107 DOI: 10.1126/science.ade8064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 12/19/2023] [Indexed: 02/10/2024]
Abstract
Penile erection is mediated by the corpora cavernosa, a trabecular-like vascular bed that enlarges upon vasodilation, but its regulation is not completely understood. Here, we show that perivascular fibroblasts in the corpora cavernosa support vasodilation by reducing norepinephrine availability. The effect on penile blood flow depends on the number of fibroblasts, which is regulated by erectile activity. Erection dynamically alters the positional arrangement of fibroblasts, temporarily down-regulating Notch signaling. Inhibition of Notch increases fibroblast numbers and consequently raises penile blood flow. Continuous Notch activation lowers fibroblast numbers and reduces penile blood perfusion. Recurrent erections stimulate fibroblast proliferation and limit vasoconstriction, whereas aging reduces the number of fibroblasts and lowers penile blood flow. Our findings reveal adaptive, erectile activity-dependent modulation of penile blood flow by fibroblasts.
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Affiliation(s)
| | - David Oliveira Dias
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Wing Fung Hau
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Anais Julien
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Daniel Holl
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Maria Garcia-Collado
- Department of Medical Biochemistry and Biophysics, Division of Vascular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Soniya Savant
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Evelina Vågesjö
- Department of Medical Cell Biology, Division of Integrative Physiology, Uppsala University, 751 23 Uppsala, Sweden
| | - Mia Phillipson
- Department of Medical Cell Biology, Division of Integrative Physiology, Uppsala University, 751 23 Uppsala, Sweden
| | - Lars Jakobsson
- Department of Medical Biochemistry and Biophysics, Division of Vascular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Christian Göritz
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
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8
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Ferrada E, Wiedmer T, Wang WA, Frommelt F, Steurer B, Klimek C, Lindinger S, Osthushenrich T, Garofoli A, Brocchetti S, Bradberry S, Huang J, MacNamara A, Scarabottolo L, Ecker GF, Malarstig A, Superti-Furga G. Experimental and Computational Analysis of Newly Identified Pathogenic Mutations in the Creatine Transporter SLC6A8. J Mol Biol 2024; 436:168383. [PMID: 38070861 DOI: 10.1016/j.jmb.2023.168383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/26/2023] [Accepted: 12/01/2023] [Indexed: 12/24/2023]
Abstract
Creatine is an essential metabolite for the storage and rapid supply of energy in muscle and nerve cells. In humans, impaired metabolism, transport, and distribution of creatine throughout tissues can cause varying forms of mental disability, also known as creatine deficiency syndrome (CDS). So far, 80 mutations in the creatine transporter (SLC6A8) have been associated to CDS. To better understand the effect of human genetic variants on the physiology of SLC6A8 and their possible impact on CDS, we studied 30 missense variants including 15 variants of unknown significance, two of which are reported here for the first time. We expressed these variants in HEK293 cells and explored their subcellular localization and transport activity. We also applied computational methods to predict variant effect and estimate site-specific changes in thermodynamic stability. To explore variants that might have a differential effect on the transporter's conformers along the transport cycle, we constructed homology models of the inward facing, and outward facing conformations. In addition, we used mass-spectrometry to study proteins that interact with wild type SLC6A8 and five selected variants in HEK293 cells. In silico models of the protein complexes revealed how two variants impact the interaction interface of SLC6A8 with other proteins and how pathogenic variants lead to an enrichment of ER protein partners. Overall, our integrated analysis disambiguates the pathogenicity of 15 variants of unknown significance revealing diverse mechanisms of pathogenicity, including two previously unreported variants obtained from patients suffering from the creatine deficiency syndrome.
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Affiliation(s)
- Evandro Ferrada
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria.
| | - Tabea Wiedmer
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Wen-An Wang
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Fabian Frommelt
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Barbara Steurer
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Christoph Klimek
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Sabrina Lindinger
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | | | - Andrea Garofoli
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | | | | | - Jiahui Huang
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | | | | | - Gerhard F Ecker
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Anders Malarstig
- Pfizer Worldwide Research, Development and Medical, Stockholm, Sweden
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria; Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
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9
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Li M, Zhang X, Chen S, Liu H, Zhang YW. Unique Substrate Recognition and Sodium-Substrate Binding Stoichiometry in a Bacterial Serotonin Transporter, TuriSERT. Int J Mol Sci 2023; 24:17112. [PMID: 38069433 PMCID: PMC10707687 DOI: 10.3390/ijms242317112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 11/27/2023] [Accepted: 12/02/2023] [Indexed: 12/18/2023] Open
Abstract
All resolved high-resolution structures of the transporters in the neurotransmitter sodium symporter (NSS) family revealed that the NSS members share common structural and mechanistic features for substrate and ion binding and transport. However, a recently reported bacterial orthologue of the human serotonin transporter (hSERT), TuriSERT, possesses a structural characteristic specific for amino acid substrate binding but does transport a biogenic amine. The unique structural feature of TuriSERT requires a novel configuration for coordinating its substrate and ions. In the present study, we characterized TuriSERT expressed in Escherichia coli cells with a fluorescent substrate by biochemical, structural, and pharmacological approaches. Substrate transport by TuriSERT requires Na+ but not Cl-. Replacement of Asp262 by asparagine renders TuriSERT Cl--dependent. Substitutions of the corresponding Na1 residues did not alter Na+ dependence on substrate transport, whereas the mutation of a Na2 site residue led to a loss of transport activity, suggesting that Na+ binds only to the Na2 site in TuriSERT. In addition, substitutions of several residues essential for recognizing 5-hydroxytryptamine (5-HT) in hSERT had little effect on 5-HT displacement potency in transport assay for TuriSERT. In contrast, mutations of the residues that are proposed to coordinate with 5-HT in our docking model dramatically reduced 5-HT displacement. Furthermore, our results indicated that all tested antidepressants showed a weak inhibitory effect on TuriSERT. The present study demonstrated the existence of a unique substrate binding site and 1:1 stoichiometry of sodium-substrate binding in TuriSERT, a novel structural finding for the NSS transporters.
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Affiliation(s)
| | | | | | | | - Yuan-Wei Zhang
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China; (M.L.); (X.Z.); (S.C.); (H.L.)
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10
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Booij J, Tellier SP, Seibyl J, Vriend C. Dopamine Transporter Availability in Early Parkinson's Disease is Dependent on Sunlight Exposure. Mov Disord 2023; 38:2131-2135. [PMID: 37670567 DOI: 10.1002/mds.29597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/15/2023] [Accepted: 08/17/2023] [Indexed: 09/07/2023] Open
Abstract
BACKGROUND Preliminary studies suggested seasonality of dopaminergic functioning, but it is unknown whether dopamine transporter (DAT) expression in humans is also dependent on the seasons. We, therefore, investigated seasonal and sunlight-dependent effects on DAT availability in early Parkinson's disease (PD) patients and healthy controls. METHODS DAT single-photon emission computed tomography scans (n = 730) were gathered from the Parkinson's Progression Marker Initiative (PPMI) database. We used global horizontal irradiance (GHI) as proxy for sun exposure/month and assessed associations between striatal DAT availability and season (autumn/winter versus spring/summer), GHI and latitude of the PPMI site. RESULTS In PD patients, DAT availability in the left caudate nucleus was higher in spring/summer (B [standard error (SE)] = 0.05 [0.02], P = 0.03) and positively associated with higher sun exposure (B [SE] = 0.59 [0.22] × 10-3 , P = 0.007). Latitude (in degrees north) of the PPMI site was negatively associated with DAT availability in both PD and healthy controls. CONCLUSION Striatal DAT availability may be influenced by daylight exposure. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Jan Booij
- Department of Radiology and Nuclear Medicine, Brain Imaging, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Sem P Tellier
- Department of Psychiatry, and Department of Anatomy and Neuroscience, Brain Imaging, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - John Seibyl
- Institute for Neurodegenerative Disorders, New Haven, Connecticut, USA
| | - Chris Vriend
- Department of Psychiatry, and Department of Anatomy and Neuroscience, Brain Imaging, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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11
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Nguyen VT, Harris AC, Eltit JM. Structural and functional perspectives on interactions between synthetic cathinones and monoamine transporters. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2023; 99:83-124. [PMID: 38467490 DOI: 10.1016/bs.apha.2023.09.001] [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] [Indexed: 03/13/2024]
Abstract
Synthetic cathinone derivatives comprise a family of psychoactive compounds structurally related to amphetamine. Over the last decade, clandestine chemists have synthesized a consistent stream of innovative cathinone derivatives to outpace governmental regulatory restrictions. Many of these unregulated substances are produced and distributed as designer drugs. Two of the principal chemical scaffolds exploited to expand the synthetic cathinone family are methcathinone and α-pyrrolidinopentiophenone (or α-pyrrolidinovalerophenone, α-PVP). These compounds' main physiological targets are monoamine transporters, where they promote addiction by potentiating dopaminergic neurotransmission. This chapter describes techniques used to study the pharmacodynamic properties of cathinones at monoamine transporters in vitro. Biochemical techniques described include uptake inhibition and release assays in rat brain synaptosomes and in mammalian expression systems. Electrophysiological techniques include current measurements using the voltage clamp technique. We describe a Ca2+ mobilization assay wherein voltage-gated Ca2+ channels function as reporters to study the action of synthetic cathinones at monoamine transporters. We discuss results from systematic structure-activity relationship studies on simple and complex cathinones at monoamine transporters with an emphasis on identifying structural moieties that modulate potency and selectivity at these transporters. Moreover, different profiles of selectivity at monoamine transporters directly predict compounds associated with behavioral and subjective effects within animals and humans. In conclusion, clarification of the structural aspects of compounds which modulate potency and selectivity at monoamine transporters is critical to identify and predict potential addictive drugs. This knowledge may allow prompt allocation of resources toward drugs that represent the greatest threats after drugs are identified by forensic laboratories.
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Affiliation(s)
- Vy T Nguyen
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Alan C Harris
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Jose M Eltit
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States.
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12
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Karabulut S, Kaur H, Gauld JW. Applications and Potential of In Silico Approaches for Psychedelic Chemistry. Molecules 2023; 28:5966. [PMID: 37630218 PMCID: PMC10459288 DOI: 10.3390/molecules28165966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Molecular-level investigations of the Central Nervous System have been revolutionized by the development of computational methods, computing power, and capacity advances. These techniques have enabled researchers to analyze large amounts of data from various sources, including genomics, in vivo, and in vitro drug tests. In this review, we explore how computational methods and informatics have contributed to our understanding of mental health disorders and the development of novel drugs for neurological diseases, with a special focus on the emerging field of psychedelics. In addition, the use of state-of-the-art computational methods to predict the potential of drug compounds and bioinformatic tools to integrate disparate data sources to create predictive models is also discussed. Furthermore, the challenges associated with these methods, such as the need for large datasets and the diversity of in vitro data, are explored. Overall, this review highlights the immense potential of computational methods and informatics in Central Nervous System research and underscores the need for continued development and refinement of these techniques and more inclusion of Quantitative Structure-Activity Relationships (QSARs).
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Affiliation(s)
- Sedat Karabulut
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada;
| | - Harpreet Kaur
- Pharmala Biotech, 82 Richmond Street E, Toronto, ON M5C 1P1, Canada;
| | - James W. Gauld
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada;
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13
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Yang D, Zhao Z, Tajkhorshid E, Gouaux E. Structures and membrane interactions of native serotonin transporter in complexes with psychostimulants. Proc Natl Acad Sci U S A 2023; 120:e2304602120. [PMID: 37436958 PMCID: PMC10629533 DOI: 10.1073/pnas.2304602120] [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: 03/20/2023] [Accepted: 05/03/2023] [Indexed: 07/14/2023] Open
Abstract
The serotonin transporter (SERT) is a member of the SLC6 neurotransmitter transporter family that mediates serotonin reuptake at presynaptic nerve terminals. SERT is the target of both therapeutic antidepressant drugs and psychostimulant substances such as cocaine and methamphetamines, which are small molecules that perturb normal serotonergic transmission by interfering with serotonin transport. Despite decades of studies, important functional aspects of SERT such as the oligomerization state of native SERT and its interactions with potential proteins remain unresolved. Here, we develop methods to isolate SERT from porcine brain (pSERT) using a mild, nonionic detergent, utilize fluorescence-detection size-exclusion chromatography to investigate its oligomerization state and interactions with other proteins, and employ single-particle cryo-electron microscopy to elucidate the structures of pSERT in complexes with methamphetamine or cocaine, providing structural insights into psychostimulant recognition and accompanying pSERT conformations. Methamphetamine and cocaine both bind to the central site, stabilizing the transporter in an outward open conformation. We also identify densities attributable to multiple cholesterol or cholesteryl hemisuccinate (CHS) molecules, as well as to a detergent molecule bound to the pSERT allosteric site. Under our conditions of isolation, we find that pSERT is best described as a monomeric entity, isolated without interacting proteins, and is ensconced by multiple cholesterol or CHS molecules.
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Affiliation(s)
- Dongxue Yang
- Vollum Institute, Oregon Health and Science University, Portland, OR97239
| | - Zhiyu Zhao
- Department of Biochemistry, NIH Center for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - Emad Tajkhorshid
- Department of Biochemistry, NIH Center for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - Eric Gouaux
- Vollum Institute, Oregon Health and Science University, Portland, OR97239
- HHMI, Oregon Health and Science University, Portland, OR97239
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14
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Deng S, Zhang H, Gou R, Luo D, Liu Z, Zhu F, Xue W. Structure-Based Discovery of a Novel Allosteric Inhibitor against Human Dopamine Transporter. J Chem Inf Model 2023. [PMID: 37410882 DOI: 10.1021/acs.jcim.3c00477] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Human dopamine transporter (hDAT) regulates the reuptake of extracellular dopamine (DA) and is an essential therapeutic target for central nervous system (CNS) diseases. The allosteric modulation of hDAT has been identified for decades. However, the molecular mechanism underlying the transportation is still elusive, which hinders the rational design of allosteric modulators against hDAT. Here, a systematic structure-based method was performed to explore allosteric sites on hDAT in inward-open (IO) conformation and to screen compounds with allosteric affinity. First, the model of the hDAT structure was constructed based on the recently reported Cryo-EM structure of the human serotonin transporter (hSERT) and Gaussian-accelerated molecular dynamics (GaMD) simulation was further utilized for the identification of intermediate energetic stable states of the transporter. Then, with the potential druggable allosteric site on hDAT in IO conformation, virtual screening of seven enamine chemical libraries (∼440,000 compounds) was processed, resulting in 10 compounds being purchased for in vitro assay and with Z1078601926 discovered to allosterically inhibit hDAT (IC50 = 0.527 [0.284; 0.988] μM) when nomifensine was introduced as an orthosteric ligand. Finally, the synergistic effect underlying the allosteric inhibition of hDAT by Z1078601926 and nomifensine was explored using additional GaMD simulation and postbinding free energy analysis. The hit compound discovered in this work not only provides a good starting point for lead optimization but also demonstrates the usability of the method for the structure-based discovery of novel allosteric modulators of other therapeutic targets.
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Affiliation(s)
- Shengzhe Deng
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Haiwei Zhang
- Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Department of Pathology, Chongqing University Cancer Hospital, Chongqing 400030, China
| | - Rongpei Gou
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Ding Luo
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Zerong Liu
- Central Nervous System Drug Key Laboratory of Sichuan Province, Sichuan Credit Pharmaceutical Co., Ltd., Luzhou 646000, China
| | - Feng Zhu
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Weiwei Xue
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
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15
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Tu G, Xu B, Luo D, Liu J, Liu Z, Chen G, Xue W. Multi-state Model-Based Identification of Cryptic Allosteric Sites on Human Serotonin Transporter. ACS Chem Neurosci 2023; 14:1686-1694. [PMID: 37067527 DOI: 10.1021/acschemneuro.3c00155] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2023] Open
Abstract
Serotonin transporter (SERT) plays a fundamental role in taking the synaptic cleft serotonin back to the presynaptic neuron. The discovery of allosteric SERT modulators represents the next-generation medication for psychiatric disorders such as depression. Here, based on the cryo-EM structures of ibogaine in complex with SERT in distinct conformations, the multiple functional structures of the transporter bound to serotonin, including outward-open (OOholo), outward-occluded (OCholo), and inward-open (IOholo and IOholo'), were carefully characterized by induced-fit docking Gaussian-accelerated molecular dynamics (IFD-GaMD) simulation and the free-energy landscape analysis. Further MM/GBSA binding free energy, per-residue contribution, and molecular interaction fingerprint calculations revealed the interaction variations of serotonin with SERT in functional structures, which confirmed the allostery of SERT during serotonin reuptake. Moreover, five unique cryptic allosteric sites, which are druggable and capable of targeting by small molecules, were identified on the characterized multistate structures. These results provide structural and energetic information for the molecular mechanism of serotonin reuptake and will provide opportunities for the development of novel therapeutics based on the identified new allosteric sites on SERT.
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Affiliation(s)
- Gao Tu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Binbin Xu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Ding Luo
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Jin Liu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Zerong Liu
- Central Nervous System Drug Key Laboratory of Sichuan Province, Sichuan Credit Pharmaceutical CO., Ltd., Luzhou 646000, China
| | - Gang Chen
- Central Nervous System Drug Key Laboratory of Sichuan Province, Sichuan Credit Pharmaceutical CO., Ltd., Luzhou 646000, China
| | - Weiwei Xue
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
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16
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Niello M, Sideromenos S, Gradisch R, O´Shea R, Schwazer J, Maier J, Kastner N, Sandtner W, Jäntsch K, Lupica CR, Hoffman AF, Lubec G, Loland CJ, Stockner T, Pollak DD, Baumann MH, Sitte HH. Persistent binding at dopamine transporters determines sustained psychostimulant effects. Proc Natl Acad Sci U S A 2023; 120:e2114204120. [PMID: 36730201 PMCID: PMC9963675 DOI: 10.1073/pnas.2114204120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 12/28/2022] [Indexed: 02/03/2023] Open
Abstract
Psychostimulants interacting with the dopamine transporter (DAT) can be used illicitly or for the treatment of specific neuropsychiatric disorders. However, they can also produce severe and persistent adverse events. Often, their pharmacological properties in vitro do not fully correlate to their pharmacological profile in vivo. Here, we investigated the pharmacological effects of enantiomers of pyrovalerone, α-pyrrolidinovalerophenone, and 3,4-methylenedioxypyrovalerone as compared to the traditional psychostimulants cocaine and methylphenidate, using a variety of in vitro, computational, and in vivo approaches. We found that in vitro drug-binding kinetics at DAT correlate with the time-course of in vivo psychostimulant action in mice. In particular, a slow dissociation (i.e., slow koff) of S-enantiomers of pyrovalerone analogs from DAT predicts their more persistent in vivo effects when compared to cocaine and methylphenidate. Overall, our findings highlight the critical importance of drug-binding kinetics at DAT for determining the in vivo profile of effects produced by psychostimulant drugs.
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Affiliation(s)
- Marco Niello
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090Vienna, Austria
| | - Spyridon Sideromenos
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, 1090Vienna, Austria
| | - Ralph Gradisch
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090Vienna, Austria
| | - Ronan O´Shea
- Electrophysiology Research Section, National Institute on Drug Abuse, NIH, Baltimore, MD21224
| | - Jakob Schwazer
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090Vienna, Austria
| | - Julian Maier
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090Vienna, Austria
| | - Nina Kastner
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090Vienna, Austria
| | - Walter Sandtner
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090Vienna, Austria
| | - Kathrin Jäntsch
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090Vienna, Austria
| | - Carl R. Lupica
- Electrophysiology Research Section, National Institute on Drug Abuse, NIH, Baltimore, MD21224
| | - Alexander F. Hoffman
- Electrophysiology Research Section, National Institute on Drug Abuse, NIH, Baltimore, MD21224
| | - Gert Lubec
- Department of Neuroproteomics, Paracelsus Medical University, 5020Salzburg, Austria
| | - Claus J. Loland
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200Copenhagen, Denmark
| | - Thomas Stockner
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090Vienna, Austria
| | - Daniela D. Pollak
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, 1090Vienna, Austria
| | - Michael H. Baumann
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, NIH, Baltimore, MD21224
| | - Harald H. Sitte
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090Vienna, Austria
- AddRess, Center for Addiction Research and Science, Medical University of Vienna, 1090Vienna, Austria
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17
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Shekar A, Mabry SJ, Cheng MH, Aguilar JI, Patel S, Zanella D, Saleeby DP, Zhu Y, Romanazzi T, Ulery-Reynolds P, Bahar I, Carter AM, Matthies HJG, Galli A. Syntaxin 1 Ser 14 phosphorylation is required for nonvesicular dopamine release. SCIENCE ADVANCES 2023; 9:eadd8417. [PMID: 36630507 PMCID: PMC9833662 DOI: 10.1126/sciadv.add8417] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 12/14/2022] [Indexed: 05/30/2023]
Abstract
Amphetamine (AMPH) is a psychostimulant that is commonly abused. The stimulant properties of AMPH are associated with its ability to increase dopamine (DA) neurotransmission. This increase is promoted by nonvesicular DA release mediated by reversal of DA transporter (DAT) function. Syntaxin 1 (Stx1) is a SNARE protein that is phosphorylated at Ser14 by casein kinase II. We show that Stx1 phosphorylation is critical for AMPH-induced nonvesicular DA release and, in Drosophila melanogaster, regulates the expression of AMPH-induced preference and sexual motivation. Our molecular dynamics simulations of the DAT/Stx1 complex demonstrate that phosphorylation of these proteins is pivotal for DAT to dwell in a DA releasing state. This state is characterized by the breakdown of two key salt bridges within the DAT intracellular gate, causing the opening and hydration of the DAT intracellular vestibule, allowing DA to bind from the cytosol, a mechanism that we hypothesize underlies nonvesicular DA release.
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Affiliation(s)
- Aparna Shekar
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Samuel J. Mabry
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mary H. Cheng
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jenny I. Aguilar
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Shalin Patel
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Daniele Zanella
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David P. Saleeby
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yanqi Zhu
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tiziana Romanazzi
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | | | - Ivet Bahar
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Angela M. Carter
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Aurelio Galli
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
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18
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Determining Ligand and Ion-Induced Conformational Changes in Serotonin Transporter with Its Fluorescent Substrates. Int J Mol Sci 2022; 23:ijms231810919. [PMID: 36142837 PMCID: PMC9503009 DOI: 10.3390/ijms231810919] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/14/2022] [Accepted: 09/16/2022] [Indexed: 01/22/2023] Open
Abstract
Conformational changes are fundamental events in the transport mechanism. The serotonin transporter (SERT) catalyzes reuptake of the neurotransmitter serotonin after its release by serotonergic neurons and is the molecular target for antidepressant drugs and psychostimulants. Despite significant progress in characterizing the structure-function relationship of SERT, its conformational mechanism has not been fully understood. We present here a cell-based method for determining conformational changes in SERT with its fluorescent substrates by fluorescence imaging analysis. This method fluorometrically measures accessibility of strategically positioned cysteine residues in the substrate permeation pathway to calculate the rate constants of reactivity with MTS reagents in live or permeabilized cells. We validated this method by investigating ligand and ion-induced conformational changes in both the extracellular and cytoplasmic pathways of SERT. Furthermore, we applied this method for examining the influence of Cl- binding and vilazodone inhibition on SERT conformation. Our results showed that Cl- ion, in the presence of Na+, facilitates the conformational conversion from outward to inward open states, and that vilazodone binding stabilizes SERT in an outward open and inward-closed conformation. The present work provided insights into the conformational mechanism of SERT and also indicated that the cell-based fluorometric method is robust, straightforward to perform, and potentially applicable to any monoamine transporters in exploring the transport mechanism and mechanism of action of therapeutic agents for the treatment of several psychiatric disorders.
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19
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Abram M, Jakubiec M, Reeb K, Cheng MH, Gedschold R, Rapacz A, Mogilski S, Socała K, Nieoczym D, Szafarz M, Latacz G, Szulczyk B, Kalinowska-Tłuścik J, Gawel K, Esguerra CV, Wyska E, Müller CE, Bahar I, Fontana ACK, Wlaź P, Kamiński RM, Kamiński K. Discovery of ( R)- N-Benzyl-2-(2,5-dioxopyrrolidin-1-yl)propanamide [ (R)-AS-1], a Novel Orally Bioavailable EAAT2 Modulator with Drug-like Properties and Potent Antiseizure Activity In Vivo. J Med Chem 2022; 65:11703-11725. [PMID: 35984707 PMCID: PMC9469208 DOI: 10.1021/acs.jmedchem.2c00534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
(R)-7 [(R)-AS-1] showed broad-spectrum antiseizure activity across in vivo mouse seizure models: maximal electroshock (MES), 6 Hz (32/44 mA), acute pentylenetetrazol (PTZ), and PTZ-kindling. A remarkable separation between antiseizure activity and CNS-related adverse effects was also observed. In vitro studies with primary glia cultures and COS-7 cells expressing the glutamate transporter EAAT2 showed enhancement of glutamate uptake, revealing a stereoselective positive allosteric modulator (PAM) effect, further supported by molecular docking simulations. (R)-7 [(R)-AS-1] was not active in EAAT1 and EAAT3 assays and did not show significant off-target activity, including interactions with targets reported for marketed antiseizure drugs, indicative of a novel and unprecedented mechanism of action. Both in vivo pharmacokinetic and in vitro absorption, distribution, metabolism, excretion, toxicity (ADME-Tox) profiles confirmed the favorable drug-like potential of the compound. Thus, (R)-7 [(R)-AS-1] may be considered as the first-in-class small-molecule PAM of EAAT2 with potential for further preclinical and clinical development in epilepsy and possibly other CNS disorders.
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Affiliation(s)
- Michał Abram
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688Krakow, Poland
| | - Marcin Jakubiec
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688Krakow, Poland
| | - Katelyn Reeb
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania19102, United States
| | - Mary Hongying Cheng
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania15213, United States
| | - Robin Gedschold
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, An der Immenburg 4, D-53121Bonn, Germany
| | - Anna Rapacz
- Department of Pharmacodynamics, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688Krakow, Poland
| | - Szczepan Mogilski
- Department of Pharmacodynamics, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688Krakow, Poland
| | - Katarzyna Socała
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033Lublin, Poland
| | - Dorota Nieoczym
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033Lublin, Poland
| | - Małgorzata Szafarz
- Department of Pharmacokinetics and Physical Pharmacy, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688Krakow, Poland
| | - Gniewomir Latacz
- Department of Technology and Biotechnology of Drugs, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688Krakow, Poland
| | - Bartłomiej Szulczyk
- Department of Pharmacodynamics, Centre for Preclinical Research and Technology, Medical University of Warsaw, Banacha 1B, 02-097Warsaw, Poland
| | - Justyna Kalinowska-Tłuścik
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387Krakow, Poland
| | - Kinga Gawel
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego 8B, 20-090Lublin, Poland
| | - Camila V Esguerra
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway, University of Oslo, Gaustadalléen 21, Forskningsparken, 0349Oslo, Norway
| | - Elżbieta Wyska
- Department of Pharmacokinetics and Physical Pharmacy, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688Krakow, Poland
| | - Christa E Müller
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, An der Immenburg 4, D-53121Bonn, Germany
| | - Ivet Bahar
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania15213, United States
| | - Andréia C K Fontana
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania19102, United States
| | - Piotr Wlaź
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033Lublin, Poland
| | - Rafał M Kamiński
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688Krakow, Poland
| | - Krzysztof Kamiński
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688Krakow, Poland
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20
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Del Alamo D, Meiler J, Mchaourab HS. Principles of Alternating Access in LeuT-fold Transporters: Commonalities and Divergences. J Mol Biol 2022; 434:167746. [PMID: 35843285 DOI: 10.1016/j.jmb.2022.167746] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/08/2022] [Accepted: 07/09/2022] [Indexed: 11/15/2022]
Abstract
Found in all domains of life, transporters belonging to the LeuT-fold class mediate the import and exchange of hydrophilic and charged compounds such as amino acids, metals, and sugar molecules. Nearly two decades of investigations on the eponymous bacterial transporter LeuT have yielded a library of high-resolution snapshots of its conformational cycle linked by solution-state experimental data obtained from multiple techniques. In parallel, its topology has been observed in symporters and antiporters characterized by a spectrum of substrate specificities and coupled to gradients of distinct ions. Here we review and compare mechanistic models of transport for LeuT, its well-studied homologs, as well as functionally distant members of the fold, emphasizing the commonalities and divergences in alternating access and the corresponding energy landscapes. Our integrated summary illustrates how fold conservation, a hallmark of the LeuT fold, coincides with divergent choreographies of alternating access that nevertheless capitalize on recurrent structural motifs. In addition, it highlights the knowledge gap that hinders the leveraging of the current body of research into detailed mechanisms of transport for this important class of membrane proteins.
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Affiliation(s)
- Diego Del Alamo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA; Department of Chemistry, Vanderbilt University, Nashville, TN, USA. https://twitter.com/DdelAlamo
| | - Jens Meiler
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA; Institute for Drug Discovery, Leipzig University, Leipzig, DE, USA. https://twitter.com/MeilerLab
| | - Hassane S Mchaourab
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
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21
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Neurotransmitters-Key Factors in Neurological and Neurodegenerative Disorders of the Central Nervous System. Int J Mol Sci 2022; 23:ijms23115954. [PMID: 35682631 PMCID: PMC9180936 DOI: 10.3390/ijms23115954] [Citation(s) in RCA: 56] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/22/2022] [Accepted: 05/24/2022] [Indexed: 12/14/2022] Open
Abstract
Neurotransmitters are molecules that amplify, transmit, and convert signals in cells, having an essential role in information transmission throughout the nervous system. Hundreds of such chemicals have been discovered in the last century, continuing to be identified and studied concerning their action on brain health. These substances have been observed to influence numerous functions, including emotions, thoughts, memories, learning, and movements. Thus, disturbances in neurotransmitters’ homeostasis started being correlated with a plethora of neurological and neurodegenerative disorders. In this respect, the present paper aims to describe the most important neurotransmitters, broadly classified into canonical (e.g., amino acids, monoamines, acetylcholine, purines, soluble gases, neuropeptides) and noncanonical neurotransmitters (e.g., exosomes, steroids, D-aspartic acid), and explain their link with some of the most relevant neurological conditions. Moreover, a brief overview of the recently developed neurotransmitters’ detection methods is offered, followed by several considerations on the modulation of these substances towards restoring homeostasis.
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22
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Huang B, Liu H, Wu Y, Li C, Tang Q, Zhang YW. Two Lignan Glycosides from Albizia julibrissin Durazz. Noncompetitively Inhibit Serotonin Transporter. Pharmaceuticals (Basel) 2022; 15:ph15030344. [PMID: 35337141 PMCID: PMC8954383 DOI: 10.3390/ph15030344] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/07/2022] [Accepted: 03/10/2022] [Indexed: 12/11/2022] Open
Abstract
Albizia julibrissin Durazz. is one of the most common herbs used for depression and anxiety treatment, but its molecular basis and mechanism of action as an antidepressant or anxiolytic drug are not understood. In this study, we separated and identified two lignan glycosides that inhibit serotonin transporter (SERT) noncompetitively by decreasing Vmax with little change in Km for its fluorescence substrate. In addition, treatment with lignan glycosides did not alter total and cell surface expression levels of the transporter protein. The two compounds decreased the accessibility of a cysteine residue placed in the extracellular substrate permeation pathway by inducing a conformational shift toward an outward-closed state of SERT. These results are consistent with molecular docking for the association of the lignan glycosides to the allosteric site in SERT. The present work supports the proposal that these compounds act on SERT by a novel underlying mechanism of action different from that of conventional antidepressant drugs.
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Affiliation(s)
- Bishan Huang
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China; (B.H.); (H.L.); (Y.W.); (C.L.)
| | - Hanhe Liu
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China; (B.H.); (H.L.); (Y.W.); (C.L.)
| | - Yingyao Wu
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China; (B.H.); (H.L.); (Y.W.); (C.L.)
| | - Chan Li
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China; (B.H.); (H.L.); (Y.W.); (C.L.)
| | - Qingfa Tang
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China;
- Guangdong Provincial Key Laboratory of Chinese Medicine Pharmaceutics, Guangzhou 510515, China
| | - Yuan-Wei Zhang
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China; (B.H.); (H.L.); (Y.W.); (C.L.)
- Correspondence:
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23
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Chan MC, Selvam B, Young HJ, Procko E, Shukla D. The substrate import mechanism of the human serotonin transporter. Biophys J 2022; 121:715-730. [PMID: 35114149 PMCID: PMC8943754 DOI: 10.1016/j.bpj.2022.01.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/18/2021] [Accepted: 01/25/2022] [Indexed: 11/17/2022] Open
Abstract
The serotonin transporter (SERT) initiates the reuptake of extracellular serotonin in the synapse to terminate neurotransmission. The cryogenic electron microscopy structures of SERT bound to ibogaine and the physiological substrate serotonin resolved in different states have provided a glimpse of the functional conformations at atomistic resolution. However, the conformational dynamics and structural transitions to intermediate states are not fully understood. Furthermore, the molecular basis of how serotonin is recognized and transported remains unclear. In this study, we performed unbiased microsecond-long simulations of the human SERT to investigate the structural dynamics to various intermediate states and elucidated the complete substrate import pathway. Using Markov state models, we characterized a sequential order of conformational-driven ion-coupled substrate binding and transport events and calculated the free energy barriers of conformation transitions associated with the import mechanism. We find that the transition from the occluded to inward-facing state is the rate-limiting step for substrate import and that the substrate decreases the free energy barriers to achieve the inward-facing state. Our study provides insights on the molecular basis of dynamics-driven ion-substrate recognition and transport of SERT that can serve as a model for other closely related neurotransmitter transporters.
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Affiliation(s)
- Matthew C Chan
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Balaji Selvam
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Heather J Young
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Erik Procko
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois; Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois; Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Diwakar Shukla
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois; Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois; National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Urbana, Illinois; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois; NIH Center for Macromolecular Modeling and Bioinformatics, University of Illinois at Urbana-Champaign, Urbana, Illinois.
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24
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Refai O, Aggarwal S, Cheng MH, Gichi Z, Salvino JM, Bahar I, Blakely RD, Mortensen OV. Allosteric Modulator KM822 Attenuates Behavioral Actions of Amphetamine in Caenorhabditis elegans through Interactions with the Dopamine Transporter DAT-1. Mol Pharmacol 2022; 101:123-131. [PMID: 34906999 PMCID: PMC8969146 DOI: 10.1124/molpharm.121.000400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 12/03/2021] [Indexed: 11/22/2022] Open
Abstract
Aberrant dopamine (DA) signaling is associated with several psychiatric disorders, such as autism, bipolar disorder, addiction, and Parkinson's disease, and several medications that target the DA transporter (DAT) can induce or treat these disorders. In addition, psychostimulants, such as cocaine and D-amphetamine (AMPH), rely on the competitive interactions with the transporter's substrate binding site to produce their rewarding effects. Agents that exhibit noncompetitive, allosteric modulation of DAT remain an important topic of investigation due to their potential therapeutic applications. We previously identified a novel allosteric modulator of human DAT, KM822, that can decrease the affinity of cocaine for DAT and attenuate cocaine-elicited behaviors; however, whether DAT is the sole mediator of KM822 actions in vivo is unproven given the large number of potential off-target sites. Here, we provide in silico and in vitro evidence that the allosteric site engaged by KM822 is conserved between human DAT and Caenorhabditis elegans DAT-1. KM822 binds to a similar pocket in DAT-1 as previously identified in human DAT. In functional dopamine uptake assays, KM822 affects the interaction between AMPH and DAT-1 by reducing the affinity of AMPH for DAT-1. Finally, through a combination of genetic and pharmacological in vivo approaches we provide evidence that KM822 diminishes the behavioral actions of AMPH on swimming-induced paralysis through a direct allosteric modulation of DAT-1. More broadly, our findings demonstrate allosteric modulation of DAT as a behavior modifying strategy and suggests that Caenorhabditis elegans can be operationalized to identify and investigate the interactions of DAT allosteric modulators. SIGNIFICANCE STATEMENT: We previously demonstrated that the dopamine transporter (DAT) allosteric modulator KM822 decreases cocaine affinity for human DAT. Here, using in silico and in vivo genetic approaches, we extend this finding to interactions with amphetamine, demonstrating evolutionary conservation of the DAT allosteric site. In Caenorhabditis elegans, we report that KM822 suppresses amphetamine behavioral effects via specific interactions with DAT-1. Our findings reveal Caenorhabditis elegans as a new tool to study allosteric modulation of DAT and its behavioral consequences.
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Affiliation(s)
- Osama Refai
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Jupiter, Florida (O.R., Z.G., R.D.B.); Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, Florida (O.R., R.D.B.); Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (S.A., O.V.M.); Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (M.H.C., I.B.); and The Wistar Institute, Philadelphia, Pennsylvania (J.M.S.)
| | - Shaili Aggarwal
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Jupiter, Florida (O.R., Z.G., R.D.B.); Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, Florida (O.R., R.D.B.); Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (S.A., O.V.M.); Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (M.H.C., I.B.); and The Wistar Institute, Philadelphia, Pennsylvania (J.M.S.)
| | - Mary Hongying Cheng
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Jupiter, Florida (O.R., Z.G., R.D.B.); Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, Florida (O.R., R.D.B.); Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (S.A., O.V.M.); Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (M.H.C., I.B.); and The Wistar Institute, Philadelphia, Pennsylvania (J.M.S.)
| | - Zayna Gichi
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Jupiter, Florida (O.R., Z.G., R.D.B.); Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, Florida (O.R., R.D.B.); Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (S.A., O.V.M.); Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (M.H.C., I.B.); and The Wistar Institute, Philadelphia, Pennsylvania (J.M.S.)
| | - Joseph M Salvino
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Jupiter, Florida (O.R., Z.G., R.D.B.); Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, Florida (O.R., R.D.B.); Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (S.A., O.V.M.); Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (M.H.C., I.B.); and The Wistar Institute, Philadelphia, Pennsylvania (J.M.S.)
| | - Ivet Bahar
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Jupiter, Florida (O.R., Z.G., R.D.B.); Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, Florida (O.R., R.D.B.); Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (S.A., O.V.M.); Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (M.H.C., I.B.); and The Wistar Institute, Philadelphia, Pennsylvania (J.M.S.)
| | - Randy D Blakely
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Jupiter, Florida (O.R., Z.G., R.D.B.); Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, Florida (O.R., R.D.B.); Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (S.A., O.V.M.); Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (M.H.C., I.B.); and The Wistar Institute, Philadelphia, Pennsylvania (J.M.S.)
| | - Ole V Mortensen
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Jupiter, Florida (O.R., Z.G., R.D.B.); Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, Florida (O.R., R.D.B.); Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (S.A., O.V.M.); Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (M.H.C., I.B.); and The Wistar Institute, Philadelphia, Pennsylvania (J.M.S.)
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25
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Blackholly LR, Harris NJ, Findlay HE, Booth PJ. Cell-Free Expression to Probe Co-Translational Insertion of an Alpha Helical Membrane Protein. Front Mol Biosci 2022; 9:795212. [PMID: 35187078 PMCID: PMC8847741 DOI: 10.3389/fmolb.2022.795212] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/11/2022] [Indexed: 01/23/2023] Open
Abstract
The majority of alpha helical membrane proteins fold co-translationally during their synthesis on the ribosome. In contrast, most mechanistic folding studies address refolding of full-length proteins from artificially induced denatured states that are far removed from the natural co-translational process. Cell-free translation of membrane proteins is emerging as a useful tool to address folding during translation by a ribosome. We summarise the benefits of this approach and show how it can be successfully extended to a membrane protein with a complex topology. The bacterial leucine transporter, LeuT can be synthesised and inserted into lipid membranes using a variety of in vitro transcription translation systems. Unlike major facilitator superfamily transporters, where changes in lipids can optimise the amount of correctly inserted protein, LeuT insertion yields are much less dependent on the lipid composition. The presence of a bacterial translocon either in native membrane extracts or in reconstituted membranes also has little influence on the yield of LeuT incorporated into the lipid membrane, except at high reconstitution concentrations. LeuT is considered a paradigm for neurotransmitter transporters and possesses a knotted structure that is characteristic of this transporter family. This work provides a method in which to probe the formation of a protein as the polypeptide chain is being synthesised on a ribosome and inserting into lipids. We show that in comparison with the simpler major facilitator transporter structures, LeuT inserts less efficiently into membranes when synthesised cell-free, suggesting that more of the protein aggregates, likely as a result of the challenging formation of the knotted topology in the membrane.
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Affiliation(s)
| | | | | | - Paula J. Booth
- Department of Chemistry, King’s College London, London, United Kingdom
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26
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Xue W, Fu T, Deng S, Yang F, Yang J, Zhu F. Molecular Mechanism for the Allosteric Inhibition of the Human Serotonin Transporter by Antidepressant Escitalopram. ACS Chem Neurosci 2022; 13:340-351. [PMID: 35041375 DOI: 10.1021/acschemneuro.1c00694] [Citation(s) in RCA: 67] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Human serotine transporter (hSERT) is one of the most influential drug targets, and its allosteric modulators (e.g., escitalopram) have emerged to be the next-generation medication for psychiatric disorders. However, the molecular mechanism underlying the allosteric modulation of hSERT is still elusive. Here, the simulation strategies of conventional (cMD) and steered (SMD) molecular dynamics were applied to investigate this molecular mechanism from distinct perspectives. First, cMD simulations revealed that escitalopram's binding to hSERT's allosteric site simultaneously enhanced its binding to the orthosteric site. Then, SMD simulation identified that the occupation of hSERT's allosteric site by escitalopram could also block its dissociation from the orthosteric site. Finally, by comparing the simulated structures of two hSERT-escitalopram complexes with and without allosteric modulation, a new conformational coupling between an extracellular (Arg104-Glu494) and an intracellular (Lys490-Glu494) salt bridge was identified. In summary, this study explored the mechanism underlying the allosteric modulation of hSERT by collectively applying two MD simulation strategies, which could facilitate our understanding of the allosteric modulations of not only hSERT but also other clinically important therapeutic targets.
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Affiliation(s)
- Weiwei Xue
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
- Central Nervous System Drug Key Laboratory of Sichuan Province, Luzhou 646000, China
| | - Tingting Fu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Shengzhe Deng
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Fengyuan Yang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Jingyi Yang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Feng Zhu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Innovation Institute for Artificial Intelligence in Medicine of Zhejiang University, Alibaba-Zhejiang University Joint Research Center of Future Digital Healthcare, Hangzhou 330110, China
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27
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Novel Molecular Targets of Antidepressants. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27020533. [PMID: 35056845 PMCID: PMC8778443 DOI: 10.3390/molecules27020533] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 12/12/2022]
Abstract
Antidepressants target a variety of proteins in the central nervous system (CNS), the most important belonging to the family of G-protein coupled receptors and the family of neurotransmitter transporters. The increasing number of crystallographic structures of these proteins have significantly contributed to the knowledge of their mechanism of action, as well as to the design of new drugs. Several computational approaches such as molecular docking, molecular dynamics, and virtual screening are useful for elucidating the mechanism of drug action and are important for drug design. This review is a survey of molecular targets for antidepressants in the CNS and computer based strategies to discover novel compounds with antidepressant activity.
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28
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Xu L, Chen LY. Effects of the N-terminal dynamics on the conformational states of human dopamine transporter. Biophys Chem 2022; 283:106765. [PMID: 35101818 PMCID: PMC8898274 DOI: 10.1016/j.bpc.2022.106765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/17/2022] [Accepted: 01/21/2022] [Indexed: 11/02/2022]
Abstract
Dopamine transporter mediates the neurotransmitter dopamine homeostasis in a sodium-dependent manner. The transport process involves an alternating access of a substrate to the extracellular and intracellular spaces, which is associated with different conformational states of the transporter. However, the underlying mechanism of modulation of the state transition remains elusive. Here we present a computational simulation study of human dopamine transporter to explore its two end states (outward-facing open and inward-facing open) that have not been determined experimentally. We show that the full-length transporter may tend to adopt the inward-facing open state in its free state. The binding of an amphetamine may not trap the transporter in the outward-facing open state with increasing length of the N-terminal. Furthermore, we identify distinct patterns in the interaction networks between the N-terminal and the intracellular region that could stabilize the state of the transporter, independent of substrate binding and phosphorylation. Our results reveal the essential role of the N-terminal dynamics in modulating the functional states of the dopamine transporter, providing molecular insights into the coupling of conformational transition and substrate passage in neurotransmitter transporters.
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29
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Magli E, Fattorusso C, Persico M, Corvino A, Esposito G, Fiorino F, Luciano P, Perissutti E, Santagada V, Severino B, Tedeschi V, Pannaccione A, Pignataro G, Caliendo G, Annunziato L, Secondo A, Frecentese F. New Insights into the Structure-Activity Relationship and Neuroprotective Profile of Benzodiazepinone Derivatives of Neurounina-1 as Modulators of the Na +/Ca 2+ Exchanger Isoforms. J Med Chem 2021; 64:17901-17919. [PMID: 34845907 PMCID: PMC8713167 DOI: 10.1021/acs.jmedchem.1c01212] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Due to the neuroprotective role of the Na+/Ca2+ exchanger (NCX) isoforms NCX1 and NCX3, we synthesized novel benzodiazepinone derivatives of the unique NCX activator Neurounina-1, named compounds 1-19. The derivatives are characterized by a benzodiazepinonic nucleus linked to five- or six-membered cyclic amines via a methylene, ethylene, or acetyl spacer. The compounds have been screened on NCX1/NCX3 isoform activities by a high-throughput screening approach, and the most promising were characterized by patch-clamp electrophysiology and Fura-2AM video imaging. We identified two novel modulators of NCX: compound 4, inhibiting NCX1 reverse mode, and compound 14, enhancing NCX1 and NCX3 activity. Compound 1 displayed neuroprotection in two preclinical models of brain ischemia. The analysis of the conformational and steric features led to the identification of the molecular volume required for selective NCX1 activation for mixed NCX1/NCX3 activation or for NCX1 inhibition, providing the first prototypal model for the design of optimized isoform modulators.
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Affiliation(s)
- Elisa Magli
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Caterina Fattorusso
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Marco Persico
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Angela Corvino
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Gianluca Esposito
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Ferdinando Fiorino
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Paolo Luciano
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Elisa Perissutti
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Vincenzo Santagada
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Beatrice Severino
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Valentina Tedeschi
- Department of Neuroscience, Division of Pharmacology, University of Naples "Federico II", via Pansini 5, 80131 Naples, Italy
| | - Anna Pannaccione
- Department of Neuroscience, Division of Pharmacology, University of Naples "Federico II", via Pansini 5, 80131 Naples, Italy
| | - Giuseppe Pignataro
- Department of Neuroscience, Division of Pharmacology, University of Naples "Federico II", via Pansini 5, 80131 Naples, Italy
| | - Giuseppe Caliendo
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | | | - Agnese Secondo
- Department of Neuroscience, Division of Pharmacology, University of Naples "Federico II", via Pansini 5, 80131 Naples, Italy
| | - Francesco Frecentese
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
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30
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Steele TWE, Spires Z, Jones CB, Glennon RA, Dukat M, Eltit JM. Non-conserved residues dictate dopamine transporter selectivity for the potent synthetic cathinone and psychostimulant MDPV. Neuropharmacology 2021; 200:108820. [PMID: 34619165 DOI: 10.1016/j.neuropharm.2021.108820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/17/2021] [Accepted: 09/29/2021] [Indexed: 10/20/2022]
Abstract
Clandestine chemists are currently exploiting the pyrrolidinophenone scaffold to develop new designer drugs that carry the risk of abuse and overdose. These drugs promote addiction through the rewarding effects of increased dopaminergic neurotransmission. 3,4-Methylenedioxypyrovalerone (MDPV) and its analogs are illicit psychostimulants of this class that are ∼50-fold more potent than cocaine at inhibiting the human dopamine transporter (hDAT). In contrast, MDPV is a weak inhibitor at both the human serotonin transporter (hSERT) and, as it is shown here, the Drosophila melanogaster DAT (dDAT). We studied three conserved residues between hSERT and dDAT that are unique in hDAT (A117, F318, and P323 in dDAT), and one residue that is different in all three transporters (D121 in dDAT). hDAT residues were replaced in the dDAT sequence at these positions using site-directed mutagenesis and stable cell lines were generated expressing these mutant transporters. The potencies of MDPV and two of its analogs were determined using a Ca2+-mobilization assay. In this assay, voltage-gated Ca2+ channels are expressed to sense the membrane electrical depolarization evoked when dopamine is transported through DAT. Each individual mutant slightly improved MDPV's potency, but the combination of all four increased its potency ∼100-fold (2 log units) in inhibiting dDAT activity. Molecular modeling and docking studies were conducted to explore the possible mode of interaction between MDPV and DAT in silico. Two of the studied residues (F318 and P323) are at the entrance of the S1 binding site, whereas the other two (A117 and D121) face the aryl moiety of MDPV when bound to this site. Therefore, these four non-conserved residues can influence MDPV selectivity not only by stabilizing binding, but also by controlling access to its binding site at DAT.
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Affiliation(s)
- Tyler W E Steele
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, USA
| | - Zachary Spires
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, USA
| | - Charles B Jones
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, USA
| | - Richard A Glennon
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, USA
| | - Małgorzata Dukat
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, USA
| | - Jose M Eltit
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, USA.
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31
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Tomlinson ID, Kovtun O, Torres R, Bellocchio LG, Josephs T, Rosenthal SJ. A Novel Biotinylated Homotryptamine Derivative for Quantum Dot Imaging of Serotonin Transporter in Live Cells. Front Cell Neurosci 2021; 15:667044. [PMID: 34867196 PMCID: PMC8637195 DOI: 10.3389/fncel.2021.667044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 10/19/2021] [Indexed: 11/21/2022] Open
Abstract
The serotonin transporter (SERT) is the primary target for selective serotonin reuptake inhibitor (SSRI) antidepressants that are thought to exert their therapeutic effects by increasing the synaptic concentration of serotonin. Consequently, probes that can be utilized to study cellular trafficking of SERT are valuable research tools. We have developed a novel ligand (IDT785) that is composed of a SERT antagonist (a tetrahydro pyridyl indole derivative) conjugated to a biotinylated poly ethylene glycol (PEG) via a phenethyl linker. This compound was determined to be biologically active and inhibited SERT-mediated reuptake of IDT307 with the half-maximal inhibitory concentration of 7.2 ± 0.3 μM. We demonstrated that IDT785 enabled quantum dot (QD) labeling of membrane SERT in transfected HEK-293 cultures that could be blocked using the high affinity serotonin reuptake inhibitor paroxetine. Molecular docking studies suggested that IDT785 might be binding to the extracellular vestibule binding site rather than the orthosteric substrate binding site, which could be attributable to the hydrophilicity of the PEG chain and the increased loss of degrees of freedom that would be required to penetrate into the orthosteric binding site. Using IDT785, we were able to study the membrane localization and membrane dynamics of YFP-SERT heterologously expressed in HEK-293 cells and demonstrated that SERT expression was enriched in the membrane edge and in thin cellular protrusions.
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Affiliation(s)
- Ian D. Tomlinson
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Oleg Kovtun
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Ruben Torres
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States
| | | | - Travis Josephs
- Neuroscience Program, Vanderbilt University, Nashville, TN, United States
| | - Sandra J. Rosenthal
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, United States
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Nashville, TN, United States
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van Galen KA, Booij J, Schrantee A, Adriaanse SM, Unmehopa UA, Fliers E, Schwartz GJ, DiLeone RJ, Ter Horst KW, la Fleur SE, Serlie MJ. The response to prolonged fasting in hypothalamic serotonin transporter availability is blunted in obesity. Metabolism 2021; 123:154839. [PMID: 34331964 PMCID: PMC8994212 DOI: 10.1016/j.metabol.2021.154839] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 07/17/2021] [Accepted: 07/20/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND AND AIMS Serotonergic and dopaminergic systems in the brain are essential for homeostatic and reward-associated regulation of food intake and systemic energy metabolism. It is largely unknown how fasting influences these systems or if such effects are altered in humans with obesity. We therefore aimed to evaluate the effects of fasting on hypothalamic/thalamic serotonin transporter (SERT) and striatal dopamine transporter (DAT) availability in lean subjects and subjects with obesity. METHODS In this randomized controlled cross-over trial, we assessed the effects of 12 vs 24 h of fasting on SERT and DAT availability in the hypothalamus/thalamus and striatum, respectively, using SPECT imaging in 10 lean men and 10 men with obesity. RESULTS As compared with the 12-h fast, a 24-h fast increased hypothalamic SERT availability in lean men, but not in men with obesity. We observed high inter-individual variation in the effects of fasting on thalamic SERT and striatal DAT, with no differences between lean men and those with obesity. In all subjects, fasting-induced increases in circulating free fatty acid (FFA) concentrations were associated with an increase in hypothalamic SERT availability and a decrease in striatal DAT availability. Multiple regression analysis showed that changes in plasma insulin and FFAs together accounted for 44% of the observed variation in striatal DAT availability. CONCLUSION Lean men respond to prolonged fasting by increasing hypothalamic SERT availability, whereas this response is absent in men with obesity. Inter-individual differences in the adaptations of the cerebral serotonergic and dopaminergic systems to fasting may, in part, be explained by changes in peripheral metabolic signals of fasting, including FFAs and insulin.
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Affiliation(s)
- Katy A van Galen
- Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Location AMC, Amsterdam, the Netherlands
| | - Jan Booij
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Location AMC, Amsterdam, the Netherlands
| | - Anouk Schrantee
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Location AMC, Amsterdam, the Netherlands
| | - Sofie M Adriaanse
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Location AMC, Amsterdam, the Netherlands
| | - Unga A Unmehopa
- Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Location AMC, Amsterdam, the Netherlands
| | - Eric Fliers
- Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Location AMC, Amsterdam, the Netherlands
| | - Gary J Schwartz
- Fleischer Institute for Diabetes and Metabolism, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Ralph J DiLeone
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Kasper W Ter Horst
- Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Location AMC, Amsterdam, the Netherlands
| | - Susanne E la Fleur
- Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Location AMC, Amsterdam, the Netherlands; Laboratory of Endocrinology, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, the Netherlands; Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, the Netherlands
| | - Mireille J Serlie
- Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Location AMC, Amsterdam, the Netherlands.
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Khananshvili D. The Archaeal Na +/Ca 2+ Exchanger (NCX_Mj) as a Model of Ion Transport for the Superfamily of Ca 2+/CA Antiporters. Front Chem 2021; 9:722336. [PMID: 34409017 PMCID: PMC8366772 DOI: 10.3389/fchem.2021.722336] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 07/20/2021] [Indexed: 11/13/2022] Open
Abstract
The superfamily of Calcium/Cation (Ca2+/CA) antiporters extrude Ca2+ from the cytosol or subcellular compartments in exchange with Na+, K+, H+, Li+, or Mg2+ and thereby provide a key mechanism for Ca2+ signaling and ion homeostasis in biological systems ranging from bacteria to humans. The structure-dynamic determinants of ion selectivity and transport rates remain unclear, although this is of primary physiological significance. Despite wide variances in the ion selectivity and transport rates, the Ca2+/CA proteins share structural motifs, although it remains unclear how the ion recognition/binding is coupled to the ion translocation events. Here, the archaeal Na+/Ca2+ exchanger (NCX_Mj) is considered as a structure-based model that can help to resolve the ion transport mechanisms by using X-ray, HDX-MS, ATR-FTIR, and computational approaches in conjunction with functional analyses of mutants. Accumulating data reveal that the local backbone dynamics at ion-coordinating residues is characteristically constrained in apo NCX_Mj, which may predefine the affinity and stability of ion-bound species in the ground and transition states. The 3Na+ or 1Ca2+ binding to respective sites of NCX_Mj rigidify the backbone dynamics at specific segments, where the ion-dependent compression of the ion-permeating four-helix bundle (TM2, TM3, TM7, and TM8) induces the sliding of the two-helix cluster (TM1/TM6) on the protein surface to switch the OF (outward-facing) and IF (inward-facing) conformations. Taking into account the common structural elements shared by Ca2+/CAs, NCX_Mj may serve as a model for studying the structure-dynamic and functional determinants of ion-coupled alternating access, transport catalysis, and ion selectivity in Ca2+/CA proteins.
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Affiliation(s)
- Daniel Khananshvili
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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34
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Chen F, Shi Q, Pei F, Vogt A, Porritt RA, Garcia G, Gomez AC, Cheng MH, Schurdak ME, Liu B, Chan SY, Arumugaswami V, Stern AM, Taylor DL, Arditi M, Bahar I. A systems-level study reveals host-targeted repurposable drugs against SARS-CoV-2 infection. Mol Syst Biol 2021; 17:e10239. [PMID: 34339582 PMCID: PMC8328275 DOI: 10.15252/msb.202110239] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 06/10/2021] [Accepted: 06/11/2021] [Indexed: 12/22/2022] Open
Abstract
Understanding the mechanism of SARS-CoV-2 infection and identifying potential therapeutics are global imperatives. Using a quantitative systems pharmacology approach, we identified a set of repurposable and investigational drugs as potential therapeutics against COVID-19. These were deduced from the gene expression signature of SARS-CoV-2-infected A549 cells screened against Connectivity Map and prioritized by network proximity analysis with respect to disease modules in the viral-host interactome. We also identified immuno-modulating compounds aiming at suppressing hyperinflammatory responses in severe COVID-19 patients, based on the transcriptome of ACE2-overexpressing A549 cells. Experiments with Vero-E6 cells infected by SARS-CoV-2, as well as independent syncytia formation assays for probing ACE2/SARS-CoV-2 spike protein-mediated cell fusion using HEK293T and Calu-3 cells, showed that several predicted compounds had inhibitory activities. Among them, salmeterol, rottlerin, and mTOR inhibitors exhibited antiviral activities in Vero-E6 cells; imipramine, linsitinib, hexylresorcinol, ezetimibe, and brompheniramine impaired viral entry. These novel findings provide new paths for broadening the repertoire of compounds pursued as therapeutics against COVID-19.
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Affiliation(s)
- Fangyuan Chen
- Department of Computational and Systems BiologySchool of MedicineUniversity of PittsburghPittsburghPAUSA
- School of MedicineTsinghua UniversityBeijingChina
| | - Qingya Shi
- Department of Computational and Systems BiologySchool of MedicineUniversity of PittsburghPittsburghPAUSA
- School of MedicineTsinghua UniversityBeijingChina
| | - Fen Pei
- Department of Computational and Systems BiologySchool of MedicineUniversity of PittsburghPittsburghPAUSA
- University of Pittsburgh Drug Discovery InstitutePittsburghPAUSA
| | - Andreas Vogt
- Department of Computational and Systems BiologySchool of MedicineUniversity of PittsburghPittsburghPAUSA
- University of Pittsburgh Drug Discovery InstitutePittsburghPAUSA
| | - Rebecca A Porritt
- Department of PediatricsDivision of Pediatric Infectious Diseases and ImmunologyCedars‐Sinai Medical CenterLos AngelesCAUSA
- Biomedical Sciences, Infectious and Immunologic Diseases Research CenterCedars‐Sinai Medical CenterLos AngelesCAUSA
| | - Gustavo Garcia
- Department of Molecular and Medical PharmacologyDavid Geffen School of MedicineUniversity of CaliforniaLos AngelesCAUSA
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell ResearchUniversity of CaliforniaLos AngelesCAUSA
| | - Angela C Gomez
- Department of PediatricsDivision of Pediatric Infectious Diseases and ImmunologyCedars‐Sinai Medical CenterLos AngelesCAUSA
| | - Mary Hongying Cheng
- Department of Computational and Systems BiologySchool of MedicineUniversity of PittsburghPittsburghPAUSA
| | - Mark E Schurdak
- Department of Computational and Systems BiologySchool of MedicineUniversity of PittsburghPittsburghPAUSA
- University of Pittsburgh Drug Discovery InstitutePittsburghPAUSA
| | - Bing Liu
- Department of Computational and Systems BiologySchool of MedicineUniversity of PittsburghPittsburghPAUSA
| | - Stephen Y Chan
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine InstituteUniversity of Pittsburgh Medical CenterPittsburghPAUSA
- Division of CardiologyDepartment of MedicineUniversity of Pittsburgh Medical CenterPittsburghPAUSA
| | - Vaithilingaraja Arumugaswami
- Department of Molecular and Medical PharmacologyDavid Geffen School of MedicineUniversity of CaliforniaLos AngelesCAUSA
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell ResearchUniversity of CaliforniaLos AngelesCAUSA
| | - Andrew M Stern
- Department of Computational and Systems BiologySchool of MedicineUniversity of PittsburghPittsburghPAUSA
- University of Pittsburgh Drug Discovery InstitutePittsburghPAUSA
| | - D Lansing Taylor
- Department of Computational and Systems BiologySchool of MedicineUniversity of PittsburghPittsburghPAUSA
- University of Pittsburgh Drug Discovery InstitutePittsburghPAUSA
| | - Moshe Arditi
- Department of PediatricsDivision of Pediatric Infectious Diseases and ImmunologyCedars‐Sinai Medical CenterLos AngelesCAUSA
- Biomedical Sciences, Infectious and Immunologic Diseases Research CenterCedars‐Sinai Medical CenterLos AngelesCAUSA
| | - Ivet Bahar
- Department of Computational and Systems BiologySchool of MedicineUniversity of PittsburghPittsburghPAUSA
- University of Pittsburgh Drug Discovery InstitutePittsburghPAUSA
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35
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Ochi T, Vyalova NM, Losenkov IS, Paderina DZ, Pozhidaev IV, Loonen AJM, Simutkin GG, Bokhan NA, Wilffert B, Ivanova SA. Preliminary Pharmacogenetic Study to Explore Putative Dopaminergic Mechanisms of Antidepressant Action. J Pers Med 2021; 11:jpm11080731. [PMID: 34442374 PMCID: PMC8401614 DOI: 10.3390/jpm11080731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/24/2021] [Accepted: 07/24/2021] [Indexed: 12/13/2022] Open
Abstract
Background: There is sufficient evidence that interference of dopaminergic neurotransmission contributes to the therapeutic effects of antidepressants in unipolar and bipolar depression. Methods: Hamilton depression rating scale (HAMD 17) scores of 163 at least moderately ill patients with major depressive disorders were used to establish treatment response. HAMD 17 score status was measured before initiation, after two weeks, and after four weeks of treatment with various antidepressants. The possible association between response and genotype in a total of 14 variants of dopamine neurotransmission-related proteins was investigated. Results: DRD4 rs11246226 CA heterozygous patients were found with a greater improvement of HAMD 17 score when compared to homozygous C patients during 0–2 weeks and 0–4 weeks. Patients with MAOB rs1799836 heterozygous GA and homozygous A also demonstrated improved scores during 2–4 weeks and 0–4 weeks. Conclusions: The results are preliminary due to the limited population size and the small number of variants. Further research into the involvement of habenular dopamine D4 receptors in the antidepressant response is desirable.
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Affiliation(s)
- Taichi Ochi
- PharmacoTherapy, Epidemiology and Economics, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713AV Groningen, The Netherlands; (T.O.); (B.W.)
| | - Natalya M. Vyalova
- Tomsk National Research Medical Center of the Russian Academy of Sciences, Mental Health Research Institute, Aleutskaya Str., 4, 634014 Tomsk, Russia; (N.M.V.); (I.S.L.); (D.Z.P.); (I.V.P.); (G.G.S.); (N.A.B.); (S.A.I.)
| | - Innokentiy S. Losenkov
- Tomsk National Research Medical Center of the Russian Academy of Sciences, Mental Health Research Institute, Aleutskaya Str., 4, 634014 Tomsk, Russia; (N.M.V.); (I.S.L.); (D.Z.P.); (I.V.P.); (G.G.S.); (N.A.B.); (S.A.I.)
| | - Diana Z. Paderina
- Tomsk National Research Medical Center of the Russian Academy of Sciences, Mental Health Research Institute, Aleutskaya Str., 4, 634014 Tomsk, Russia; (N.M.V.); (I.S.L.); (D.Z.P.); (I.V.P.); (G.G.S.); (N.A.B.); (S.A.I.)
- Department of Cytology and Genetics, National Research Tomsk State University, Lenin Ave., 36, 634050 Tomsk, Russia
| | - Ivan V. Pozhidaev
- Tomsk National Research Medical Center of the Russian Academy of Sciences, Mental Health Research Institute, Aleutskaya Str., 4, 634014 Tomsk, Russia; (N.M.V.); (I.S.L.); (D.Z.P.); (I.V.P.); (G.G.S.); (N.A.B.); (S.A.I.)
- Department of Cytology and Genetics, National Research Tomsk State University, Lenin Ave., 36, 634050 Tomsk, Russia
| | - Anton J. M. Loonen
- PharmacoTherapy, Epidemiology and Economics, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713AV Groningen, The Netherlands; (T.O.); (B.W.)
- Correspondence: ; Tel.: +31-503-637-576
| | - German G. Simutkin
- Tomsk National Research Medical Center of the Russian Academy of Sciences, Mental Health Research Institute, Aleutskaya Str., 4, 634014 Tomsk, Russia; (N.M.V.); (I.S.L.); (D.Z.P.); (I.V.P.); (G.G.S.); (N.A.B.); (S.A.I.)
| | - Nikolay A. Bokhan
- Tomsk National Research Medical Center of the Russian Academy of Sciences, Mental Health Research Institute, Aleutskaya Str., 4, 634014 Tomsk, Russia; (N.M.V.); (I.S.L.); (D.Z.P.); (I.V.P.); (G.G.S.); (N.A.B.); (S.A.I.)
- Department of Psychotherapy and Psychological Counseling, National Research Tomsk State University, Lenin Ave., 36, 634050 Tomsk, Russia
- Department of Psychiatry, Addictology and Psychotherapy, Siberian State Medical University, Moskovsky Trakt, 2, 634050 Tomsk, Russia
| | - Bob Wilffert
- PharmacoTherapy, Epidemiology and Economics, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713AV Groningen, The Netherlands; (T.O.); (B.W.)
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, Hanzeplein 1, 9713GZ Groningen, The Netherlands
| | - Svetlana A. Ivanova
- Tomsk National Research Medical Center of the Russian Academy of Sciences, Mental Health Research Institute, Aleutskaya Str., 4, 634014 Tomsk, Russia; (N.M.V.); (I.S.L.); (D.Z.P.); (I.V.P.); (G.G.S.); (N.A.B.); (S.A.I.)
- Department of Psychiatry, Addictology and Psychotherapy, Siberian State Medical University, Moskovsky Trakt, 2, 634050 Tomsk, Russia
- Division for Control and Diagnostics, School of Non-Destructive Testing and Security, National Research Tomsk Polytechnic University, Lenin Ave., 30, 634050 Tomsk, Russia
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Castagna M, Cinquetti R, Verri T, Vacca F, Giovanola M, Barca A, Romanazzi T, Roseti C, Galli A, Bossi E. The Lepidopteran KAAT1 and CAATCH1: Orthologs to Understand Structure-Function Relationships in Mammalian SLC6 Transporters. Neurochem Res 2021; 47:111-126. [PMID: 34304372 PMCID: PMC8310414 DOI: 10.1007/s11064-021-03410-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 04/18/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022]
Abstract
To the SLC6 family belong 20 human transporters that utilize the sodium electrochemical gradient to move biogenic amines, osmolytes, amino acids and related compounds into cells. They are classified into two functional groups, the Neurotransmitter transporters (NTT) and Nutrient amino acid transporters (NAT). Here we summarize how since their first cloning in 1998, the insect (Lepidopteran) Orthologs of the SLC6 family transporters have represented very important tools for investigating functional–structural relationships, mechanism of transport, ion and pH dependence and substate interaction of the mammalian (and human) counterparts.
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Affiliation(s)
- Michela Castagna
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Trentacoste 2, 20134, Milan, Italy
| | - Raffaella Cinquetti
- Laboratory of Cellular and Molecular Physiology, Department of Biotechnology and Life Sciences, University of Insubria, via Dunant 3, 21100, Varese, Italy
| | - Tiziano Verri
- Laboratory of Applied Physiology, Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Provinciale Lecce-Monteroni, 73100, Lecce, Italy
| | - Francesca Vacca
- Laboratory of Cellular and Molecular Physiology, Department of Biotechnology and Life Sciences, University of Insubria, via Dunant 3, 21100, Varese, Italy
| | - Matteo Giovanola
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Trentacoste 2, 20134, Milan, Italy
| | - Amilcare Barca
- Laboratory of Applied Physiology, Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Provinciale Lecce-Monteroni, 73100, Lecce, Italy
| | - Tiziana Romanazzi
- Laboratory of Cellular and Molecular Physiology, Department of Biotechnology and Life Sciences, University of Insubria, via Dunant 3, 21100, Varese, Italy
| | - Cristina Roseti
- Laboratory of Cellular and Molecular Physiology, Department of Biotechnology and Life Sciences, University of Insubria, via Dunant 3, 21100, Varese, Italy.,Research Centre for Neuroscience, University of Insubria, Varese, Italy
| | - Alessandra Galli
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Trentacoste 2, 20134, Milan, Italy
| | - Elena Bossi
- Laboratory of Cellular and Molecular Physiology, Department of Biotechnology and Life Sciences, University of Insubria, via Dunant 3, 21100, Varese, Italy. .,Research Centre for Neuroscience, University of Insubria, Varese, Italy.
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Camacho-Hernandez GA, Casiraghi A, Rudin D, Luethi D, Ku TC, Guthrie DA, Straniero V, Valoti E, Schütz GJ, Sitte HH, Newman AH. Illuminating the norepinephrine transporter: fluorescent probes based on nisoxetine and talopram. RSC Med Chem 2021; 12:1174-1186. [PMID: 34355183 DOI: 10.1039/d1md00072a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 05/27/2021] [Indexed: 01/30/2023] Open
Abstract
The utilization of fluorescent ligands to study the monoamine transporters (MATs) has increased our knowledge of their function and distribution in live cell systems. In this study, we extend SAR for nisoxetine and talopram as parent compounds, to identify high affinity rhodamine-labeled fluorescent probes for the norepinephrine transporter (NET). Nisoxetine-based fluorescent probe 6 demonstrated high binding affinity (K i = 43 nM) for NET and an overall selectivity compared to the other transporters for dopamine (DAT; K i = 1540 nM) and serotonin (SERT; K i = 785 nM) in competitive radioligand binding assays. Using confocal microscopy, compound 6 was shown to stain both NET and SERT, but not DAT, at low nanomolar concentrations, in transporter-expressing cells.
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Affiliation(s)
- Gisela Andrea Camacho-Hernandez
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institutes of Drug Abuse - Intramural Research Program Baltimore MD 21224 USA
| | - Andrea Casiraghi
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institutes of Drug Abuse - Intramural Research Program Baltimore MD 21224 USA .,Department of Pharmaceutical Sciences, University of Milan Via Mangiagalli 25 20133 Milan Italy
| | - Deborah Rudin
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna Waehringer Strasse 13a 1090 Vienna Austria
| | - Dino Luethi
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna Waehringer Strasse 13a 1090 Vienna Austria.,Institute of Applied Physics TU Wien, Lehárgasse 6 1060 Vienna Austria
| | - Therese C Ku
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institutes of Drug Abuse - Intramural Research Program Baltimore MD 21224 USA
| | - Daryl A Guthrie
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institutes of Drug Abuse - Intramural Research Program Baltimore MD 21224 USA
| | - Valentina Straniero
- Department of Pharmaceutical Sciences, University of Milan Via Mangiagalli 25 20133 Milan Italy
| | - Ermanno Valoti
- Department of Pharmaceutical Sciences, University of Milan Via Mangiagalli 25 20133 Milan Italy
| | - Gerhard J Schütz
- Institute of Applied Physics TU Wien, Lehárgasse 6 1060 Vienna Austria
| | - Harald H Sitte
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna Waehringer Strasse 13a 1090 Vienna Austria
| | - Amy Hauck Newman
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institutes of Drug Abuse - Intramural Research Program Baltimore MD 21224 USA
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38
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Aggarwal S, Cheng MH, Salvino JM, Bahar I, Mortensen OV. Functional Characterization of the Dopaminergic Psychostimulant Sydnocarb as an Allosteric Modulator of the Human Dopamine Transporter. Biomedicines 2021; 9:634. [PMID: 34199621 PMCID: PMC8227285 DOI: 10.3390/biomedicines9060634] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/29/2021] [Accepted: 05/29/2021] [Indexed: 02/06/2023] Open
Abstract
The dopamine transporter (DAT) serves a critical role in controlling dopamine (DA)-mediated neurotransmission by regulating the clearance of DA from the synapse and extrasynaptic regions and thereby modulating DA action at postsynaptic DA receptors. Major drugs of abuse such as amphetamine and cocaine interact with DATs to alter their actions resulting in an enhancement in extracellular DA concentrations. We previously identified a novel allosteric site in the DAT and the related human serotonin transporter that lies outside the central orthosteric substrate- and cocaine-binding pocket. Here, we demonstrate that the dopaminergic psychostimulant sydnocarb is a ligand of this novel allosteric site. We identified the molecular determinants of the interaction between sydnocarb and DAT at the allosteric site using molecular dynamics simulations. Biochemical-substituted cysteine scanning accessibility experiments have supported the computational predictions by demonstrating the occurrence of specific interactions between sydnocarb and amino acids within the allosteric site. Functional dopamine uptake studies have further shown that sydnocarb is a noncompetitive inhibitor of DAT in accord with the involvement of a site different from the orthosteric site in binding this psychostimulant. Finally, DA uptake studies also demonstrate that sydnocarb affects the interaction of DAT with both cocaine and amphetamine. In summary, these studies further strengthen the prospect that allosteric modulation of DAT activity could have therapeutic potential.
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Affiliation(s)
- Shaili Aggarwal
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, USA;
| | - Mary Hongying Cheng
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA; (M.H.C.); (I.B.)
| | | | - Ivet Bahar
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA; (M.H.C.); (I.B.)
| | - Ole Valente Mortensen
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, USA;
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Tu G, Fu T, Yang F, Yang J, Zhang Z, Yao X, Xue W, Zhu F. Understanding the Polypharmacological Profiles of Triple Reuptake Inhibitors by Molecular Simulation. ACS Chem Neurosci 2021; 12:2013-2026. [PMID: 33977725 DOI: 10.1021/acschemneuro.1c00127] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The triple reuptake inhibitors (TRIs) class is a class of effective inhibitors of human monoamine transporters (hMATs), which includes dopamine, norepinephrine, and serotonin transporters (hDATs, hNETs, and hSERTs). Due to the high degree of structural homology of the binding sites of those transporters, it is a great challenge to design potent TRIs with fine-tuned binding profiles. The molecular determinants responsible for the binding selectivity of TRIs to hDATs, hNETs, and hSERTs remain elusive. In this study, the solved X-ray crystallographic structure of hSERT in complex with escitalopram was used as a basis for modeling nine complexes of three representative TRIs (SEP225289, NS2359, and EB1020) bound to their corresponding targets. Molecular dynamics (MD) and effective post-trajectory analysis were performed to estimate the drug binding free energies and characterize the selective profiles of each TRI to hMATs. The common binding mode of studied TRIs to hMATs was revealed by hierarchical clustering analysis of the per-residue energy. Furthermore, the combined protein-ligand interaction fingerprint and residue energy contribution analysis indicated that several conserved and nonconserved "Warm Spots" such as S149, V328, and M427 in hDAT, F317, F323, and V325 in hNET and F335, F341, and V343 in hSERT were responsible for the TRI-binding selectivity. These findings provided important information for rational design of a single drug with better polypharmacological profiles through modulating multiple targets.
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Affiliation(s)
- Gao Tu
- School of Pharmaceutical Sciences, Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Chongqing University, Chongqing 401331, China
| | - Tingting Fu
- School of Pharmaceutical Sciences, Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Chongqing University, Chongqing 401331, China
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Fengyuan Yang
- School of Pharmaceutical Sciences, Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Chongqing University, Chongqing 401331, China
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jingyi Yang
- School of Pharmaceutical Sciences, Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Chongqing University, Chongqing 401331, China
| | - Zhao Zhang
- School of Pharmaceutical Sciences, Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Chongqing University, Chongqing 401331, China
| | - Xiaojun Yao
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou 730000, China
| | - Weiwei Xue
- School of Pharmaceutical Sciences, Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Chongqing University, Chongqing 401331, China
- Central Nervous System Drug Key Laboratory of Sichuan Province, Luzhou 646106, China
| | - Feng Zhu
- School of Pharmaceutical Sciences, Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Chongqing University, Chongqing 401331, China
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
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40
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Bhat S, Niello M, Schicker K, Pifl C, Sitte HH, Freissmuth M, Sandtner W. Handling of intracellular K + determines voltage dependence of plasmalemmal monoamine transporter function. eLife 2021; 10:67996. [PMID: 34061030 PMCID: PMC8192120 DOI: 10.7554/elife.67996] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 05/30/2021] [Indexed: 12/16/2022] Open
Abstract
The concentrative power of the transporters for dopamine (DAT), norepinephrine (NET), and serotonin (SERT) is thought to be fueled by the transmembrane Na+ gradient, but it is conceivable that they can also tap other energy sources, for example, membrane voltage and/or the transmembrane K+ gradient. We have addressed this by recording uptake of endogenous substrates or the fluorescent substrate APP+(4-(4-dimethylamino)phenyl-1-methylpyridinium) under voltage control in cells expressing DAT, NET, or SERT. We have shown that DAT and NET differ from SERT in intracellular handling of K+. In DAT and NET, substrate uptake was voltage-dependent due to the transient nature of intracellular K+ binding, which precluded K+ antiport. SERT, however, antiports K+ and achieves voltage-independent transport. Thus, there is a trade-off between maintaining constant uptake and harvesting membrane potential for concentrative power, which we conclude to occur due to subtle differences in the kinetics of co-substrate ion binding in closely related transporters.
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Affiliation(s)
- Shreyas Bhat
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Marco Niello
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Klaus Schicker
- Division of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Christian Pifl
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Harald H Sitte
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Michael Freissmuth
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Walter Sandtner
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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41
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Xu L, Chen LY. Association of sigma-1 receptor with dopamine transporter attenuates the binding of methamphetamine via distinct helix-helix interactions. Chem Biol Drug Des 2021; 97:1194-1209. [PMID: 33754484 PMCID: PMC8113090 DOI: 10.1111/cbdd.13841] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/23/2021] [Accepted: 03/07/2021] [Indexed: 02/06/2023]
Abstract
Dopamine transporter (DAT) and sigma-1 receptor (σ1R) are potential therapeutic targets to reduce the psychostimulant effects induced by methamphetamine (METH). Interaction of σ1R with DAT could modulate the binding of METH, but the molecular basis of the association of the two transmembrane proteins and how their interactions mediate the binding of METH to DAT or σ1R remain unclear. Here, we characterize the protein-ligand and protein-protein interactions at a molecular level by various theoretical approaches. The present results show that METH adopts a different binding pose in the binding pocket of σ1R and is more likely to act as an agonist. The relatively lower binding affinity of METH to σ1R supports the role of antagonists as inhibitors that protect against METH-induced effects. We demonstrate that σ1R could bind to Drosophila melanogaster DAT (dDAT) through interactions with either the transmembrane helix α12 or α5 of dDAT. Our results showed that the truncated σ1R displays stronger association with dDAT than the full-length σ1R. Although different helix-helix interactions between σ1R and dDAT lead to distinct effects on the dynamics of individual protein, both associations attenuate the binding affinity of METH to dDAT, particularly in the interactions with the helix α5 of dDAT. Together, the present study provides the first computational investigation on the molecular mechanism of coupling METH binding and the association of σ1R with dDAT.
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Affiliation(s)
- Liang Xu
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, USA
| | - Liao Y Chen
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, USA
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42
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Aguilar JI, Cheng MH, Font J, Schwartz AC, Ledwitch K, Duran A, Mabry SJ, Belovich AN, Zhu Y, Carter AM, Shi L, Kurian MA, Fenollar-Ferrer C, Meiler J, Ryan RM, Mchaourab HS, Bahar I, Matthies HJ, Galli A. Psychomotor impairments and therapeutic implications revealed by a mutation associated with infantile Parkinsonism-Dystonia. eLife 2021; 10:68039. [PMID: 34002696 PMCID: PMC8131106 DOI: 10.7554/elife.68039] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/02/2021] [Indexed: 12/30/2022] Open
Abstract
Parkinson disease (PD) is a progressive, neurodegenerative disorder affecting over 6.1 million people worldwide. Although the cause of PD remains unclear, studies of highly penetrant mutations identified in early-onset familial parkinsonism have contributed to our understanding of the molecular mechanisms underlying disease pathology. Dopamine (DA) transporter (DAT) deficiency syndrome (DTDS) is a distinct type of infantile parkinsonism-dystonia that shares key clinical features with PD, including motor deficits (progressive bradykinesia, tremor, hypomimia) and altered DA neurotransmission. Here, we define structural, functional, and behavioral consequences of a Cys substitution at R445 in human DAT (hDAT R445C), identified in a patient with DTDS. We found that this R445 substitution disrupts a phylogenetically conserved intracellular (IC) network of interactions that compromise the hDAT IC gate. This is demonstrated by both Rosetta molecular modeling and fine-grained simulations using hDAT R445C, as well as EPR analysis and X-ray crystallography of the bacterial homolog leucine transporter. Notably, the disruption of this IC network of interactions supported a channel-like intermediate of hDAT and compromised hDAT function. We demonstrate that Drosophila melanogaster expressing hDAT R445C show impaired hDAT activity, which is associated with DA dysfunction in isolated brains and with abnormal behaviors monitored at high-speed time resolution. We show that hDAT R445C Drosophila exhibit motor deficits, lack of motor coordination (i.e. flight coordination) and phenotypic heterogeneity in these behaviors that is typically associated with DTDS and PD. These behaviors are linked with altered dopaminergic signaling stemming from loss of DA neurons and decreased DA availability. We rescued flight coordination with chloroquine, a lysosomal inhibitor that enhanced DAT expression in a heterologous expression system. Together, these studies shed some light on how a DTDS-linked DAT mutation underlies DA dysfunction and, possibly, clinical phenotypes shared by DTDS and PD.
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Affiliation(s)
- Jenny I Aguilar
- Department of Pharmacology, Vanderbilt University, Nashville, United States.,Department of Surgery, University of Alabama at Birmingham, Birmingham, United States
| | - Mary Hongying Cheng
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, United States
| | - Josep Font
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Alexandra C Schwartz
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, United States
| | - Kaitlyn Ledwitch
- Center for Structural Biology, Vanderbilt University, Nashville, United States.,Department of Chemistry, Vanderbilt University, Nashville, United States
| | - Amanda Duran
- Center for Structural Biology, Vanderbilt University, Nashville, United States.,Department of Chemistry, Vanderbilt University, Nashville, United States
| | - Samuel J Mabry
- Department of Surgery, University of Alabama at Birmingham, Birmingham, United States
| | - Andrea N Belovich
- Department of Biomedical Sciences, Idaho College of Osteopathic Medicine, Meridian, United States
| | - Yanqi Zhu
- Department of Surgery, University of Alabama at Birmingham, Birmingham, United States
| | - Angela M Carter
- Department of Surgery, University of Alabama at Birmingham, Birmingham, United States
| | - Lei Shi
- Computational Chemistry and Molecular Biophysics Section, NIDA, NIH, Baltimore, United States
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences, University College London (UCL), London, United Kingdom
| | | | - Jens Meiler
- Center for Structural Biology, Vanderbilt University, Nashville, United States.,Department of Chemistry, Vanderbilt University, Nashville, United States.,Institute for Drug Discovery, Leipzig University Medical School, Leipzig, Germany
| | - Renae Monique Ryan
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Hassane S Mchaourab
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, United States
| | - Ivet Bahar
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, United States
| | - Heinrich Jg Matthies
- Department of Surgery, University of Alabama at Birmingham, Birmingham, United States
| | - Aurelio Galli
- Department of Surgery, University of Alabama at Birmingham, Birmingham, United States.,Center for Inter-systemic Networks and Enteric Medical Advances, University of Alabama at Birmingham, Birmingham, United States
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43
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Pidathala S, Mallela AK, Joseph D, Penmatsa A. Structural basis of norepinephrine recognition and transport inhibition in neurotransmitter transporters. Nat Commun 2021; 12:2199. [PMID: 33850134 PMCID: PMC8044178 DOI: 10.1038/s41467-021-22385-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 03/01/2021] [Indexed: 12/23/2022] Open
Abstract
Norepinephrine is a biogenic amine neurotransmitter that has widespread effects on alertness, arousal and pain sensation. Consequently, blockers of norepinephrine uptake have served as vital tools to treat depression and chronic pain. Here, we employ the Drosophila melanogaster dopamine transporter as a surrogate for the norepinephrine transporter and determine X-ray structures of the transporter in its substrate-free and norepinephrine-bound forms. We also report structures of the transporter in complex with inhibitors of chronic pain including duloxetine, milnacipran and a synthetic opioid, tramadol. When compared to dopamine, we observe that norepinephrine binds in a different pose, in the vicinity of subsite C within the primary binding site. Our experiments reveal that this region is the binding site for chronic pain inhibitors and a determinant for norepinephrine-specific reuptake inhibition, thereby providing a paradigm for the design of specific inhibitors for catecholamine neurotransmitter transporters.
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Affiliation(s)
| | | | - Deepthi Joseph
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Aravind Penmatsa
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India.
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44
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Dynamic control of the dopamine transporter in neurotransmission and homeostasis. NPJ Parkinsons Dis 2021; 7:22. [PMID: 33674612 PMCID: PMC7935902 DOI: 10.1038/s41531-021-00161-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 01/08/2021] [Indexed: 01/31/2023] Open
Abstract
The dopamine transporter (DAT) transports extracellular dopamine into the intracellular space contributing to the regulation of dopamine neurotransmission. A reduction of DAT density is implicated in Parkinson's disease (PD) by neuroimaging; dopamine turnover is dopamine turnover is elevated in early symptomatic PD and in presymptomatic individuals with monogenic mutations causal for parkinsonism. As an integral plasma membrane protein, DAT surface expression is dynamically regulated through endocytic trafficking, enabling flexible control of dopamine signaling in time and space, which in turn critically modulates movement, motivation and learning behavior. Yet the cellular machinery and functional implications of DAT trafficking remain enigmatic. In this review we summarize mechanisms governing DAT trafficking under normal physiological conditions and discuss how PD-linked mutations may disturb DAT homeostasis. We highlight the complexity of DAT trafficking and reveal DAT dysregulation as a common theme in genetic models of parkinsonism.
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45
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Sorkina T, Cheng MH, Bagalkot TR, Wallace C, Watkins SC, Bahar I, Sorkin A. Direct coupling of oligomerization and oligomerization-driven endocytosis of the dopamine transporter to its conformational mechanics and activity. J Biol Chem 2021; 296:100430. [PMID: 33610553 PMCID: PMC8010718 DOI: 10.1016/j.jbc.2021.100430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/08/2021] [Accepted: 02/16/2021] [Indexed: 12/15/2022] Open
Abstract
Dopamine transporter (DAT) mediates the reuptake of synaptically released dopamine, and thus controls the duration and intensity of dopamine neurotransmission. Mammalian DAT has been observed to form oligomers, although the mechanisms of oligomerization and its role in DAT activity and trafficking remain largely unknown. We discovered a series of small molecule compounds that stabilize trimers and induce high-order oligomers of DAT and concomitantly promote its clathrin-independent endocytosis. Using a combination of chemical cross-linking, fluorescence resonance energy transfer microscopy, antibody-uptake endocytosis assay, live-cell lattice light sheet microscopy, ligand binding and substrate transport kinetics analyses, and molecular modeling and simulations, we investigated molecular basis of DAT oligomerization and endocytosis induced by these compounds. Our study showed that small molecule–induced DAT oligomerization and endocytosis are favored by the inward-facing DAT conformation and involve interactions of four hydrophobic residues at the interface between transmembrane (TM) helices TM4 and TM9. Surprisingly, a corresponding quadruple DAT mutant displays altered dopamine transport kinetics and increased cocaine-analog binding. The latter is shown to originate from an increased preference for outward-facing conformation and inward-to-outward transition. Taken together, our results demonstrate a direct coupling between conformational dynamics of DAT, functional activity of the transporter, and its oligomerization leading to endocytosis. The high specificity of such coupling for DAT makes the TM4-9 hub a new target for pharmacological modulation of DAT activity and subcellular localization.
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Affiliation(s)
- Tatiana Sorkina
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Mary Hongying Cheng
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Tarique R Bagalkot
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Callen Wallace
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Simon C Watkins
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Ivet Bahar
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alexander Sorkin
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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46
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Gong W, Liu Y, Zhao Y, Wang S, Han Z, Li C. Equally Weighted Multiscale Elastic Network Model and Its Comparison with Traditional and Parameter-Free Models. J Chem Inf Model 2021; 61:921-937. [PMID: 33496590 DOI: 10.1021/acs.jcim.0c01178] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dynamical properties of proteins play an essential role in their function exertion. The elastic network model (ENM) is an effective and efficient tool in characterizing the intrinsic dynamical properties encoded in biomacromolecule structures. The Gaussian network model (GNM) and anisotropic network model (ANM) are the two often-used ENM models. Here, we introduce an equally weighted multiscale ENM (equally weighted mENM) based on the original mENM (denoted as mENM), in which fitting weights of Kirchhoff/Hessian matrixes in mENM are removed since they neglect the details of pairwise interactions. Then, we perform its comparison with the mENM, traditional ENM, and parameter-free ENM (pfENM) in reproducing dynamical properties for the six representative proteins whose molecular dynamics (MD) trajectories are available in http://mmb.pcb.ub.es/MoDEL/. In the results, for B-factor prediction, mENM performs best, while the equally weighted mENM performs also well, better than the traditional ENM and pfENM models. As to the dynamical cross-correlation map calculation, mENM performs worst, while the results produced from the equally weighted mENM and pfENM models are close to those from MD trajectories with the latter a little better than the former. Furthermore, encouragingly, the equally weighted mANM displays the best performance in capturing the functional motional modes, followed by pfANM and traditional ANM models, while the mANM fails in all the cases. This work is helpful for strengthening the understanding of the elastic network model and provides a valuable guide for researchers to utilize the model to explore protein dynamics.
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Affiliation(s)
- Weikang Gong
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Yang Liu
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Yanpeng Zhao
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Shihao Wang
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Zhongjie Han
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Chunhua Li
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
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47
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Li ZH, Ma PK, Huang YF, Zhang Z, Zheng W, Chen JH, Guo CE, Chen N, Bi XN, Zhang YJ. Jiaotai Pill () Alleviates Insomnia through Regulating Monoamine and Organic Cation Transporters in Rats. Chin J Integr Med 2021; 27:183-191. [PMID: 33420587 DOI: 10.1007/s11655-021-3284-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To reveal the effect and mechanism of Jiaotai Pill (, JTP) on insomniac rats. METHODS The insomniac model was established by intraperitoneal injection of p-chlorophenylalanine (PCPA). In behavioral experiments, rats were divided into control, insomniac model, JTP [3.3 g/(kg•d)], and diazepam [4 mg/(kg•d)] groups. The treatment effect of JTP was evaluated by weight measurement (increasement of body weight), open field test (number of crossings) and forced swimming test (immobility time). A high performance liquid chromatography-electrochemical detection (HPLC-ECD) method was built to determine the concentration of monoamine transmitters in hypothalamus and peripheral organs from normal, model, JTP, citalopram [30 mg/(kg•d)], maprotiline [40 mg/(kg•d)] and bupropion [40 mg/(kg•d)] groups. Expressions of serotonin transporter (SERT), dopamine transporter (DAT), and norepinephrine transporter (NET) were analyzed by quantitative polymerase chain reaction (qPCR) and Western blot in normal, model and JTP groups. A high performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS/MS) method was established to determine the pharmacokinetics, urine cumulative excretion of metformin in vivo, and tissue slice uptake in vitro, which were applied to assess the activity of organic cation transporters (OCTs) in hypothalamus and peripheral organs. RESULTS Compared with the insomniac model group, the body weight and spontaneous locomotor were increased, and the immobility time was decreased after treatment with JTP (P<0.01). Both serotonin and dopamine contents in hypothalamus and peripheral organs were increased (P<0.01). The norepinephrine content was increased in peripheral organs and decreased in hypothalamus (P<0.05 or P<0.01). At the same time, SERT, DAT, OCT1, OCT2, and OCT3 were down-regulated in hypothalamus and peripheral organs (P<0.05). NET was down-regulated in peripheral organs and up-regulated in hypothalamus (P<0.05 or P<0.01). Moreover, the activity of OCTs in hypothalamus and peripheral organs was inhibited (P<0.05). CONCLUSION JTP alleviates insomnia through regulation of monoaminergic system and OCTs in hypothalamus and peripheral organs.
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Affiliation(s)
- Zhi-Hui Li
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Peng-Kai Ma
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | | | - Zhe Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Wei Zheng
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Jian-Hua Chen
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Chang-E Guo
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Ning Chen
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Xin-Ning Bi
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Yu-Jie Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China.
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48
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Romanazzi T, Zanella D, Cheng MH, Smith B, Carter AM, Galli A, Bahar I, Bossi E. Bile Acids Gate Dopamine Transporter Mediated Currents. Front Chem 2021; 9:753990. [PMID: 34957043 PMCID: PMC8702627 DOI: 10.3389/fchem.2021.753990] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 11/16/2021] [Indexed: 11/21/2022] Open
Abstract
Bile acids (BAs) are molecules derived from cholesterol that are involved in dietary fat absorption. New evidence supports an additional role for BAs as regulators of brain function. Sterols such as cholesterol interact with monoamine transporters, including the dopamine (DA) transporter (DAT) which plays a key role in DA neurotransmission and reward. This study explores the interactions of the BA, obeticholic acid (OCA), with DAT and characterizes the regulation of DAT activity via both electrophysiology and molecular modeling. We expressed murine DAT (mDAT) in Xenopus laevis oocytes and confirmed its functionality. Next, we showed that OCA promotes a DAT-mediated inward current that is Na+-dependent and not regulated by intracellular calcium. The current induced by OCA was transient in nature, returning to baseline in the continued presence of the BA. OCA also transiently blocked the DAT-mediated Li+-leak current, a feature that parallels DA action and indicates direct binding to the transporter in the absence of Na+. Interestingly, OCA did not alter DA affinity nor the ability of DA to promote a DAT-mediated inward current, suggesting that the interaction of OCA with the transporter is non-competitive, regarding DA. Docking simulations performed for investigating the molecular mechanism of OCA action on DAT activity revealed two potential binding sites. First, in the absence of DA, OCA binds DAT through interactions with D421, a residue normally involved in coordinating the binding of the Na+ ion to the Na2 binding site (Borre et al., J. Biol. Chem., 2014, 289, 25764-25773; Cheng and Bahar, Structure, 2015, 23, 2171-2181). Furthermore, we uncover a separate binding site for OCA on DAT, of equal potential functional impact, that is coordinated by the DAT residues R445 and D436. Binding to that site may stabilize the inward-facing (IF) open state by preventing the re-formation of the IF-gating salt bridges, R60-D436 and R445-E428, that are required for DA transport. This study suggests that BAs may represent novel pharmacological tools to regulate DAT function, and possibly, associated behaviors.
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Affiliation(s)
- Tiziana Romanazzi
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Daniele Zanella
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mary Hongying Cheng
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Behrgen Smith
- Department of Physics and Chemistry, Biomolecular Engineering, Milwaukee School of Engineering, Milwaukee, WI, United States
| | - Angela M Carter
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Aurelio Galli
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Ivet Bahar
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Elena Bossi
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy.,Center for Research in Neuroscience, University of Insubria, Varese, Italy
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49
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Ryuzaki S, Matsuda R, Taniguchi M. Pore Structures for High-Throughput Nanopore Devices. MICROMACHINES 2020; 11:mi11100893. [PMID: 32993177 PMCID: PMC7600762 DOI: 10.3390/mi11100893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 09/25/2020] [Accepted: 09/25/2020] [Indexed: 11/16/2022]
Abstract
Nanopore devices are expected to advance the next-generation of nanobiodevices because of their strong sensing and analyzing capabilities for single molecules and bioparticles. However, the device throughputs are not sufficiently high. Although analytes pass through a nanopore by electrophoresis, the electric field gradient is localized inside and around a nanopore structure. Thus, analytes located far from a nanopore cannot be driven by electrophoresis. Here, we report nanopore structures for high-throughput sensing, namely, inverted pyramid (IP)-shaped nanopore structures. Silicon-based IP-shaped nanopore structures create a homogeneous electric field gradient within a nanopore device, indicating that most of the analytes can pass through a nanopore by electrophoresis, even though the analytes are suspended far from the nanopore entrance. In addition, the nanostructures can be fabricated only by photolithography. The present study suggests a high potential for inverted pyramid shapes to serve as nanopore devices for high-throughput sensing.
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Affiliation(s)
- Sou Ryuzaki
- Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka 819-0395, Japan;
- PRESTO, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
- Correspondence: (S.R.); (M.T.); Tel.: +81-092-642-2726 (S.R.); +81-6-6875-2440 (M.T.)
| | - Rintaro Matsuda
- Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka 819-0395, Japan;
| | - Masateru Taniguchi
- The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan
- Correspondence: (S.R.); (M.T.); Tel.: +81-092-642-2726 (S.R.); +81-6-6875-2440 (M.T.)
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Xu L, Chen LY. Identification of a New Allosteric Binding Site for Cocaine in Dopamine Transporter. J Chem Inf Model 2020; 60:3958-3968. [PMID: 32649824 PMCID: PMC7484383 DOI: 10.1021/acs.jcim.0c00346] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dopamine (DA) transporter (DAT) is a major target for psychostimulant drugs of abuse such as cocaine that competitively binds to DAT, inhibits DA reuptake, and consequently increases synaptic DA levels. In addition to the central binding site inside DAT, the available experimental evidence suggests the existence of alternative binding sites on DAT, but detection and characterization of these sites are challenging by experiments alone. Here, we integrate multiple computational approaches to probe the potential binding sites on the wild-type Drosophila melanogaster DAT and identify a new allosteric site that displays high affinity for cocaine. This site is located on the surface of DAT, and binding of cocaine is primarily dominated by interactions with hydrophobic residues surrounding the site. We show that cocaine binding to this new site allosterically reduces the binding of DA/cocaine to the central binding pocket, and simultaneous binding of two cocaine molecules to a single DAT seems infeasible. Furthermore, we find that binding of cocaine to this site stabilizes the conformation of DAT but alters the conformational population and thereby reduces the accessibility by DA, providing molecular insights into the inhibitory mechanism of cocaine. In addition, our results indicate that the conformations induced by cocaine binding to this site may be relevant to the oligomerization of DAT, highlighting a potential role of this new site in modulating the function of DAT.
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Affiliation(s)
- Liang Xu
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, United States
| | - Liao Y Chen
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, United States
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