1
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Luo D, Zhang Y, Li Y, Liu Z, Wu H, Xue W. Structural Models of Human Norepinephrine Transporter Ensemble Reveal the Allosteric Sites and Ligand-Binding Mechanism. J Phys Chem B 2024; 128:8651-8661. [PMID: 39207306 DOI: 10.1021/acs.jpcb.4c03731] [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: 09/04/2024]
Abstract
The norepinephrine transporter (NET) plays a pivotal role in recycling norepinephrine (NE) from the synaptic cleft. However, the structures referring to the conformational heterogeneity of NET during the transport cycle remain poorly understood. Here, three structural models of NE bound to the orthosteric site of NET in outward-open (OOholo), outward-occluded (OCholo), and inward-open (IOholo) conformations were first obtained using the multistate structures of serotonin transporter as templates and further characterized through Gaussian-accelerated molecular dynamics and free energy reweighting. Analysis of the structures revealed eight potential allosteric sites on the functional-specific states of NET. One of the pharmacologically relevant pockets located at the extracellular vestibule was further verified by simulating the binding behaviors of a clinical trial drug χ-MrIA that is allosterically regulating NET. These structural and energetic insights into NET advanced our understanding of NE reuptake and paved the way for discovering novel molecules targeting the allosteric sites.
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Affiliation(s)
- Ding Luo
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Yang Zhang
- School of Pharmacy, Hebei Medical University, Shijiazhuang 050017, China
| | - Yinghong Li
- Chongqing Key Laboratory of Big Data for Bio Intelligence, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Zerong Liu
- Central Nervous System Drug Key Laboratory of Sichuan Province, Sichuan Credit Pharmaceutical Co., Ltd., Luzhou 646000, China
| | - Haibo Wu
- School of Life 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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2
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Song A, Wu X. Mechanistic insights of substrate transport and inhibitor binding revealed by high-resolution structures of human norepinephrine transporter. Cell Res 2024:10.1038/s41422-024-01024-0. [PMID: 39223283 DOI: 10.1038/s41422-024-01024-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 08/21/2024] [Indexed: 09/04/2024] Open
Affiliation(s)
- Ailong Song
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Xudong Wu
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China.
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China.
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China.
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3
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Witkowska A, Jaromirska J, Gabryelska A, Sochal M. Obstructive Sleep Apnea and Serotoninergic Signalling Pathway: Pathomechanism and Therapeutic Potential. Int J Mol Sci 2024; 25:9427. [PMID: 39273373 PMCID: PMC11395478 DOI: 10.3390/ijms25179427] [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: 07/18/2024] [Revised: 08/23/2024] [Accepted: 08/26/2024] [Indexed: 09/15/2024] Open
Abstract
Obstructive Sleep Apnea (OSA) is a disorder characterized by repeated upper airway collapse during sleep, leading to apneas and/or hypopneas, with associated symptoms like intermittent hypoxia and sleep fragmentation. One of the agents contributing to OSA occurrence and development seems to be serotonin (5-HT). Currently, the research focuses on establishing and interlinking OSA pathogenesis and the severity of the disease on the molecular neurotransmitter omnipresent in the human body-serotonin, its pathway, products, receptors, drugs affecting the levels of serotonin, or genetic predisposition. The 5-HT system is associated with numerous physiological processes such as digestion, circulation, sleep, respiration, and muscle tone-all of which are considered factors promoting and influencing the course of OSA because of correlations with comorbid conditions. Comorbidities include obesity, physiological and behavioral disorders as well as cardiovascular diseases. Additionally, both serotonin imbalance and OSA are connected with psychiatric comorbidities, such as depression, anxiety, or cognitive dysfunction. Pharmacological agents that target 5-HT receptors have shown varying degrees of efficacy in reducing the Apnea-Hypopnea Index and improving OSA symptoms. The potential role of the 5-HT signaling pathway in modulating OSA provides a promising avenue for new therapeutic interventions that could accompany the primary treatment of OSA-continuous positive airway pressure. Thus, this review aims to elucidate the complex role of 5-HT and its regulatory mechanisms in OSA pathophysiology, evaluating its potential as a therapeutic target. We also summarize the relationship between 5-HT signaling and various physiological functions, as well as its correlations with comorbid conditions.
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Affiliation(s)
- Alicja Witkowska
- Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, 92-215 Lodz, Poland
| | - Julia Jaromirska
- Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, 92-215 Lodz, Poland
| | - Agata Gabryelska
- Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, 92-215 Lodz, Poland
| | - Marcin Sochal
- Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, 92-215 Lodz, Poland
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4
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Nielsen JC, Salomon K, Kalenderoglou IE, Bargmeyer S, Pape T, Shahsavar A, Loland CJ. Structure of the human dopamine transporter in complex with cocaine. Nature 2024; 632:678-685. [PMID: 39112703 DOI: 10.1038/s41586-024-07804-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 07/09/2024] [Indexed: 08/16/2024]
Abstract
The dopamine transporter (DAT) is crucial for regulating dopamine signalling and is the prime mediator for the rewarding and addictive effects of cocaine1. As part of the neurotransmitter sodium symporter family, DAT uses the Na+ gradient across cell membranes to transport dopamine against its chemical gradient2. The transport mechanism involves both intra- and extracellular gates that control substrate access to a central site. However, the molecular intricacies of this process and the inhibitory mechanism of cocaine have remained unclear. Here, we present the molecular structure of human DAT in complex with cocaine at a resolution of 2.66 Å. Our findings reveal that DAT adopts the expected LeuT-fold, posing in an outward-open conformation with cocaine bound at the central (S1) site. Notably, while an Na+ occupies the second Na+ site (Na2), the Na1 site seems to be vacant, with the side chain of Asn82 occupying the presumed Na+ space. This structural insight elucidates the mechanism for the cocaine inhibition of human DAT and deepens our understanding of neurotransmitter transport. By shedding light on the molecular underpinnings of how cocaine acts, our study lays a foundation for the development of targeted medications to combat addiction.
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Affiliation(s)
- Jeppe C Nielsen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kristine Salomon
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Iris E Kalenderoglou
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sarah Bargmeyer
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tillmann Pape
- Structural Molecular Biology Group, Protein Structure & Function Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Core Facility for Integrated Microscopy (CFIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Azadeh Shahsavar
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Claus J Loland
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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5
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Srivastava DK, Navratna V, Tosh DK, Chinn A, Sk MF, Tajkhorshid E, Jacobson KA, Gouaux E. Structure of the human dopamine transporter and mechanisms of inhibition. Nature 2024; 632:672-677. [PMID: 39112705 PMCID: PMC11324517 DOI: 10.1038/s41586-024-07739-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 06/19/2024] [Indexed: 08/16/2024]
Abstract
The neurotransmitter dopamine has central roles in mood, appetite, arousal and movement1. Despite its importance in brain physiology and function, and as a target for illicit and therapeutic drugs, the human dopamine transporter (hDAT) and mechanisms by which it is inhibited by small molecules and Zn2+ are without a high-resolution structural context. Here we determine the structure of hDAT in a tripartite complex with the competitive inhibitor and cocaine analogue, (-)-2-β-carbomethoxy-3-β-(4-fluorophenyl)tropane2 (β-CFT), the non-competitive inhibitor MRS72923 and Zn2+ (ref. 4). We show how β-CFT occupies the central site, approximately halfway across the membrane, stabilizing the transporter in an outward-open conformation. MRS7292 binds to a structurally uncharacterized allosteric site, adjacent to the extracellular vestibule, sequestered underneath the extracellular loop 4 (EL4) and adjacent to transmembrane helix 1b (TM1b), acting as a wedge, precluding movement of TM1b and closure of the extracellular gate. A Zn2+ ion further stabilizes the outward-facing conformation by coupling EL4 to EL2, TM7 and TM8, thus providing specific insights into how Zn2+ restrains the movement of EL4 relative to EL2 and inhibits transport activity.
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Affiliation(s)
| | - Vikas Navratna
- Vollum Institute, Oregon Health and Science University, Portland, OR, USA
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Dilip K Tosh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Audrey Chinn
- Vollum Institute, Oregon Health and Science University, Portland, OR, USA
| | - Md Fulbabu Sk
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Biochemistry University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Biochemistry University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - Eric Gouaux
- Vollum Institute, Oregon Health and Science University, Portland, OR, USA.
- Howard Hughes Medical Institute, Oregon Health and Science University, Portland, OR, USA.
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6
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Tan J, Xiao Y, Kong F, Zhang X, Xu H, Zhu A, Liu Y, Lei J, Tian B, Yuan Y, Yan C. Molecular basis of human noradrenaline transporter reuptake and inhibition. Nature 2024; 632:921-929. [PMID: 39048818 DOI: 10.1038/s41586-024-07719-z] [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: 01/23/2023] [Accepted: 06/14/2024] [Indexed: 07/27/2024]
Abstract
Noradrenaline, also known as norepinephrine, has a wide range of activities and effects on most brain cell types1. Its reuptake from the synaptic cleft heavily relies on the noradrenaline transporter (NET) located in the presynaptic membrane2. Here we report the cryo-electron microscopy (cryo-EM) structures of the human NET in both its apo state and when bound to substrates or antidepressant drugs, with resolutions ranging from 2.5 Å to 3.5 Å. The two substrates, noradrenaline and dopamine, display a similar binding mode within the central substrate binding site (S1) and within a newly identified extracellular allosteric site (S2). Four distinct antidepressants, namely, atomoxetine, desipramine, bupropion and escitalopram, occupy the S1 site to obstruct substrate transport in distinct conformations. Moreover, a potassium ion was observed within sodium-binding site 1 in the structure of the NET bound to desipramine under the KCl condition. Complemented by structural-guided biochemical analyses, our studies reveal the mechanism of substrate recognition, the alternating access of NET, and elucidate the mode of action of the four antidepressants.
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Affiliation(s)
- Jiaxin Tan
- Beijing Frontier Research Center for Biological Structure, State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yuan Xiao
- Beijing Frontier Research Center for Biological Structure, State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Fang Kong
- Beijing Frontier Research Center for Biological Structure, State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xiaochun Zhang
- School of Pharmaceutical Sciences, Tsinghua University, Beijing, China
| | - Hanwen Xu
- Beijing Frontier Research Center for Biological Structure, State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Angqi Zhu
- Beijing Frontier Research Center for Biological Structure, State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yiming Liu
- Beijing Frontier Research Center for Biological Structure, State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jianlin Lei
- Beijing Frontier Research Center for Biological Structure, State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Boxue Tian
- School of Pharmaceutical Sciences, Tsinghua University, Beijing, China
| | - Yafei Yuan
- Beijing Frontier Research Center for Biological Structure, State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
| | - Chuangye Yan
- Beijing Frontier Research Center for Biological Structure, State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
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7
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Hu T, Yu Z, Zhao J, Meng Y, Salomon K, Bai Q, Wei Y, Zhang J, Xu S, Dai Q, Yu R, Yang B, Loland CJ, Zhao Y. Transport and inhibition mechanisms of the human noradrenaline transporter. Nature 2024; 632:930-937. [PMID: 39085602 DOI: 10.1038/s41586-024-07638-z] [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: 11/02/2023] [Accepted: 05/31/2024] [Indexed: 08/02/2024]
Abstract
The noradrenaline transporter (also known as norepinephrine transporter) (NET) has a critical role in terminating noradrenergic transmission by utilizing sodium and chloride gradients to drive the reuptake of noradrenaline (also known as norepinephrine) into presynaptic neurons1-3. It is a pharmacological target for various antidepressants and analgesic drugs4,5. Despite decades of research, its structure and the molecular mechanisms underpinning noradrenaline transport, coupling to ion gradients and non-competitive inhibition remain unknown. Here we present high-resolution complex structures of NET in two fundamental conformations: in the apo state, and bound to the substrate noradrenaline, an analogue of the χ-conotoxin MrlA (χ-MrlAEM), bupropion or ziprasidone. The noradrenaline-bound structure clearly demonstrates the binding modes of noradrenaline. The coordination of Na+ and Cl- undergoes notable alterations during conformational changes. Analysis of the structure of NET bound to χ-MrlAEM provides insight into how conotoxin binds allosterically and inhibits NET. Additionally, bupropion and ziprasidone stabilize NET in its inward-facing state, but they have distinct binding pockets. These structures define the mechanisms governing neurotransmitter transport and non-competitive inhibition in NET, providing a blueprint for future drug design.
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Affiliation(s)
- Tuo Hu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zhuoya Yu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jun Zhao
- Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, China
| | - Yufei Meng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Kristine Salomon
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Qinru Bai
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yiqing Wei
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jinghui Zhang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Shujing Xu
- Beijing Institute of Biotechnology, Beijing, China
| | - Qiuyun Dai
- Beijing Institute of Biotechnology, Beijing, China
| | - Rilei Yu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Bei Yang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Claus J Loland
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Yan Zhao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
- Beijing Key Laboratory of Mental Disorders, National Clinical Research Center for Mental Disorders & National Center for Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China.
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8
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Swanepoel AA, Truter C, Viljoen FP, Myburgh JG, Harvey BH. Temporal Dynamics of Plasma Catecholamines, Metabolic and Immune Markers, and the Corticosterone:DHEA Ratio in Farmed Crocodiles before and after an Acute Stressor. Animals (Basel) 2024; 14:2236. [PMID: 39123762 PMCID: PMC11311039 DOI: 10.3390/ani14152236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 07/23/2024] [Accepted: 07/24/2024] [Indexed: 08/12/2024] Open
Abstract
Commercial crocodilian farms face significant economic and livestock losses attributed to stress, which may be linked to their adopted husbandry practices. The development of appropriate and modernized husbandry guidelines, particularly those focused on stress mitigation, is impeded by the limited understanding of the crocodilian stress response. Fifteen grower Nile crocodiles were subjected to simulated acute transport stress, with blood samples collected at various intervals post-stress. Plasma levels of corticosterone (CORT), dehydroepiandrosterone (DHEA), adrenaline, and noradrenaline were determined using high-performance liquid chromatography. Glucose and lactate were measured using portable meters and the heterophil-to-lymphocyte ratio (HLR) was determined via differential leucocyte counts. Significant differences were elicited after the stressor, with acute fluctuations observed in the fast-acting catecholamines (adrenaline and noradrenaline) when compared to the baseline. Downstream effects of these catecholamines and CORT appear to be associated with a persistent increase in plasma glucose and HLR. Lactate also showed acute fluctuations over time but returned to the baseline by the final measurement. DHEA, which is used in a ratio with CORT, showed fluctuations over time with an inverted release pattern to the catecholamines. The study highlights the temporal dynamics of physiological markers under acute stress, contributing to our understanding of crocodilian stress and potentially informing improved farming practices for conservation and sustainable management.
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Affiliation(s)
- Andre A. Swanepoel
- Centre of Excellence for Pharmaceutical Sciences, Department of Pharmacology, North-West University, Potchefstroom 2531, South Africa; (A.A.S.); (F.P.V.)
| | - Christoff Truter
- Stellenbosch University Water Institute, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7603, South Africa;
| | - Francois P. Viljoen
- Centre of Excellence for Pharmaceutical Sciences, Department of Pharmacology, North-West University, Potchefstroom 2531, South Africa; (A.A.S.); (F.P.V.)
| | - Jan G. Myburgh
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa;
| | - Brian H. Harvey
- Centre of Excellence for Pharmaceutical Sciences, Department of Pharmacology, North-West University, Potchefstroom 2531, South Africa; (A.A.S.); (F.P.V.)
- South African Medical Research Council Unit on Risk and Resilience in Mental Disorders, Department of Psychiatry and Neuroscience Institute, University of Cape Town, Cape Town 7505, South Africa
- The Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Deakin University, Geelong 3220, Australia
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9
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Pedersen CN, Yang F, Ita S, Xu Y, Akunuri R, Trampari S, Neumann CMT, Desdorf LM, Schiøtt B, Salvino JM, Mortensen OV, Nissen P, Shahsavar A. Cryo-EM structure of the dopamine transporter with a novel atypical non-competitive inhibitor bound to the orthosteric site. J Neurochem 2024. [PMID: 39010681 DOI: 10.1111/jnc.16179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 06/28/2024] [Accepted: 07/01/2024] [Indexed: 07/17/2024]
Abstract
The regulation of dopamine (DA) removal from the synaptic cleft is a crucial process in neurotransmission and is facilitated by the sodium- and chloride-coupled dopamine transporter DAT. Psychostimulant drugs, cocaine, and amphetamine, both block the uptake of DA, while amphetamine also triggers the release of DA. As a result, they prolong or even amplify neurotransmitter signaling. Atypical inhibitors of DAT lack cocaine-like rewarding effects and offer a promising strategy for the treatment of drug use disorders. Here, we present the 3.2 Å resolution cryo-electron microscopy structure of the Drosophila melanogaster dopamine transporter (dDAT) in complex with the atypical non-competitive inhibitor AC-4-248. The inhibitor partially binds at the central binding site, extending into the extracellular vestibule, and locks the transporter in an outward open conformation. Our findings propose mechanisms for the non-competitive inhibition of DAT and attenuation of cocaine potency by AC-4-248 and provide a basis for the rational design of more efficacious atypical inhibitors.
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Affiliation(s)
- Clara Nautrup Pedersen
- DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Fuyu Yang
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Samantha Ita
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Yibin Xu
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | | | - Sofia Trampari
- DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Caroline Marie Teresa Neumann
- DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | | | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | | | - Ole Valente Mortensen
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Poul Nissen
- DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Azadeh Shahsavar
- DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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10
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Modak A, Kilic Z, Chattrakun K, Terry DS, Kalathur RC, Blanchard SC. Single-Molecule Imaging of Integral Membrane Protein Dynamics and Function. Annu Rev Biophys 2024; 53:427-453. [PMID: 39013028 DOI: 10.1146/annurev-biophys-070323-024308] [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] [Indexed: 07/18/2024]
Abstract
Integral membrane proteins (IMPs) play central roles in cellular physiology and represent the majority of known drug targets. Single-molecule fluorescence and fluorescence resonance energy transfer (FRET) methods have recently emerged as valuable tools for investigating structure-function relationships in IMPs. This review focuses on the practical foundations required for examining polytopic IMP function using single-molecule FRET (smFRET) and provides an overview of the technical and conceptual frameworks emerging from this area of investigation. In this context, we highlight the utility of smFRET methods to reveal transient conformational states critical to IMP function and the use of smFRET data to guide structural and drug mechanism-of-action investigations. We also identify frontiers where progress is likely to be paramount to advancing the field.
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Affiliation(s)
- Arnab Modak
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
| | - Zeliha Kilic
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
| | - Kanokporn Chattrakun
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
| | - Daniel S Terry
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
| | - Ravi C Kalathur
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
| | - Scott C Blanchard
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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11
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Chen L, Huang S, Wu X, He W, Song M. Serotonin signalling in cancer: Emerging mechanisms and therapeutic opportunities. Clin Transl Med 2024; 14:e1750. [PMID: 38943041 PMCID: PMC11213692 DOI: 10.1002/ctm2.1750] [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: 03/04/2024] [Revised: 06/09/2024] [Accepted: 06/13/2024] [Indexed: 06/30/2024] Open
Abstract
BACKGROUND Serotonin (5-hydroxytryptamine) is a multifunctional bioamine serving as a neurotransmitter, peripheral hormone and mitogen in the vertebrate system. It has pleiotropic activities in central nervous system and gastrointestinal function via an orchestrated action of serotonergic elements, particularly serotonin receptor-mediated signalling cascades. The mitogenic properties of serotonin have garnered recognition for years and have been exploited for repurposing serotonergic-targeted drugs in cancer therapy. However, emerging conflicting findings necessitate a more comprehensive elucidation of serotonin's role in cancer pathogenesis. MAIN BODY AND CONCLUSION Here, we provide an overview of the biosynthesis, metabolism and action modes of serotonin. We summarise our current knowledge regarding the effects of the peripheral serotonergic system on tumourigenesis, with a specific emphasis on its immunomodulatory activities in human cancers. We also discuss the dual roles of serotonin in tumour pathogenesis and elucidate the potential of serotonergic drugs, some of which display favourable safety profiles and impressive efficacy in clinical trials, as a promising avenue in cancer treatment. KEY POINTS Primary synthesis and metabolic routes of peripheral 5-hydroxytryptamine in the gastrointestinal tract. Advanced research has established a strong association between the serotonergic components and carcinogenic mechanisms. The interplay between serotonergic signalling and the immune system within the tumour microenvironment orchestrates antitumour immune responses. Serotonergic-targeted drugs offer valuable clinical options for cancer therapy.
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Affiliation(s)
- Lulu Chen
- Department of Gastrointestinal SurgeryThe First Affiliated Hospital of Sun Yat‐Sen UniversitySun Yat‐Sen UniversityGuangzhouChina
- Institute of Precision MedicineThe First Affiliated Hospital of Sun Yat‐Sen UniversitySun Yat‐Sen UniversityGuangzhouChina
| | - Shuting Huang
- School of Public HealthSun Yat‐Sen UniversityGuangzhouChina
| | - Xiaoxue Wu
- Department of Gastrointestinal SurgeryThe First Affiliated Hospital of Sun Yat‐Sen UniversitySun Yat‐Sen UniversityGuangzhouChina
| | - Weiling He
- Department of Gastrointestinal SurgeryThe First Affiliated Hospital of Sun Yat‐Sen UniversitySun Yat‐Sen UniversityGuangzhouChina
- Department of Gastrointestinal SurgeryXiang'an Hospital of Xiamen UniversitySchool of MedicineXiamen UniversityXiamenChina
| | - Mei Song
- Institute of Precision MedicineThe First Affiliated Hospital of Sun Yat‐Sen UniversitySun Yat‐Sen UniversityGuangzhouChina
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12
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Li HZ, Pike ACW, Lotsaris I, Chi G, Hansen JS, Lee SC, Rödström KEJ, Bushell SR, Speedman D, Evans A, Wang D, He D, Shrestha L, Nasrallah C, Burgess-Brown NA, Vandenberg RJ, Dafforn TR, Carpenter EP, Sauer DB. Structure and function of the SIT1 proline transporter in complex with the COVID-19 receptor ACE2. Nat Commun 2024; 15:5503. [PMID: 38951531 PMCID: PMC11217458 DOI: 10.1038/s41467-024-48921-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 05/16/2024] [Indexed: 07/03/2024] Open
Abstract
Proline is widely known as the only proteogenic amino acid with a secondary amine. In addition to its crucial role in protein structure, the secondary amino acid modulates neurotransmission and regulates the kinetics of signaling proteins. To understand the structural basis of proline import, we solved the structure of the proline transporter SIT1 in complex with the COVID-19 viral receptor ACE2 by cryo-electron microscopy. The structure of pipecolate-bound SIT1 reveals the specific sequence requirements for proline transport in the SLC6 family and how this protein excludes amino acids with extended side chains. By comparing apo and substrate-bound SIT1 states, we also identify the structural changes that link substrate release and opening of the cytoplasmic gate and provide an explanation for how a missense mutation in the transporter causes iminoglycinuria.
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Affiliation(s)
- Huanyu Z Li
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ashley C W Pike
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Irina Lotsaris
- Molecular Biomedicine Theme, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia
| | - Gamma Chi
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Jesper S Hansen
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sarah C Lee
- School of Biosciences, University of Birmingham, Birmingham, UK
| | - Karin E J Rödström
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Simon R Bushell
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - David Speedman
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Adam Evans
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Dong Wang
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Didi He
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Leela Shrestha
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Chady Nasrallah
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicola A Burgess-Brown
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Robert J Vandenberg
- Molecular Biomedicine Theme, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia.
| | | | - Elisabeth P Carpenter
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - David B Sauer
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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13
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Alberto-Silva AS, Hemmer S, Bock HA, da Silva LA, Scott KR, Kastner N, Bhatt M, Niello M, Jäntsch K, Kudlacek O, Bossi E, Stockner T, Meyer MR, McCorvy JD, Brandt SD, Kavanagh P, Sitte HH. Bioisosteric analogs of MDMA: Improving the pharmacological profile? J Neurochem 2024. [PMID: 38898705 DOI: 10.1111/jnc.16149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 03/26/2024] [Accepted: 05/29/2024] [Indexed: 06/21/2024]
Abstract
3,4-Methylenedioxymethamphetamine (MDMA, 'ecstasy') is re-emerging in clinical settings as a candidate for the treatment of specific neuropsychiatric disorders (e.g. post-traumatic stress disorder) in combination with psychotherapy. MDMA is a psychoactive drug, typically regarded as an empathogen or entactogen, which leads to transporter-mediated monoamine release. Despite its therapeutic potential, MDMA can induce dose-, individual-, and context-dependent untoward effects outside safe settings. In this study, we investigated whether three new methylenedioxy bioisosteres of MDMA improve its off-target profile. In vitro methods included radiotracer assays, transporter electrophysiology, bioluminescence resonance energy transfer and fluorescence-based assays, pooled human liver microsome/S9 fraction incubations, metabolic stability studies, isozyme mapping, and liquid chromatography coupled to high-resolution mass spectrometry. In silico methods included molecular docking. Compared with MDMA, all three MDMA bioisosteres (ODMA, TDMA, and SeDMA) showed similar pharmacological activity at human serotonin, dopamine, and norepinephrine transporters (hSERT, hDAT, and hNET, respectively) but decreased agonist activity at 5-HT2A/2B/2C receptors. Regarding their hepatic metabolism, they differed from MDMA, with N-demethylation being the only metabolic route shared, and without forming phase II metabolites. In addition, TDMA showed an enhanced intrinsic clearance in comparison to its congeners. Additional screening for their interaction with human organic cation transporters (hOCTs) and plasma membrane monoamine transporter (hPMAT) revealed a weaker interaction of the MDMA analogs with hOCT1, hOCT2, and hPMAT. Our findings suggest that these new MDMA bioisosteres might constitute appealing therapeutic alternatives to MDMA, sparing the primary pharmacological activity at hSERT, hDAT, and hNET, but displaying a reduced activity at 5-HT2A/2B/2C receptors and alternative hepatic metabolism. Whether these MDMA bioisosteres may pose lower risk alternatives to the clinically re-emerging MDMA warrants further studies.
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Affiliation(s)
- Ana Sofia Alberto-Silva
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Selina Hemmer
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - Hailey A Bock
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Leticia Alves da Silva
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Kenneth R Scott
- Department of Pharmacology and Therapeutics, School of Medicine, Trinity Centre for Health Sciences, St James Hospital, Dublin, Ireland
| | - Nina Kastner
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Manan Bhatt
- Laboratory of Cellular and Molecular Physiology, Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Marco Niello
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Kathrin Jäntsch
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Oliver Kudlacek
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Elena Bossi
- Laboratory of Cellular and Molecular Physiology, Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
- Center for Research in Neuroscience, University of Insubria, Varese, Italy
| | - Thomas Stockner
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Markus R Meyer
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - John D McCorvy
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Cancer Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Simon D Brandt
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Pierce Kavanagh
- Department of Pharmacology and Therapeutics, School of Medicine, Trinity Centre for Health Sciences, St James Hospital, Dublin, Ireland
| | - Harald H Sitte
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
- Hourani Center for Applied Scientific Research, Al-Ahliyya Amman University, Amman, Jordan
- Center for Addiction Research and Science, Medical University of Vienna, Vienna, Austria
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14
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Mena S, Cruikshank A, Best J, Nijhout HF, Reed MC, Hashemi P. Modulation of serotonin transporter expression by escitalopram under inflammation. Commun Biol 2024; 7:710. [PMID: 38851804 PMCID: PMC11162477 DOI: 10.1038/s42003-024-06240-3] [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: 10/20/2023] [Accepted: 04/24/2024] [Indexed: 06/10/2024] Open
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are widely used for depression based on the monoamine deficiency hypothesis. However, the clinical use of these agents is controversial, in part because of their variable clinical efficacy and in part because of their delayed onset of action. Because of the complexities involved in replicating human disease and clinical dosing in animal models, the scientific community has not reached a consensus on the reasons for these phenomena. In this work, we create a theoretical hippocampal model incorporating escitalopram's pharmacokinetics, pharmacodynamics (competitive and non-competitive inhibition, and serotonin transporter (SERT) internalization), inflammation, and receptor dynamics. With this model, we simulate chronic oral escitalopram in mice showing that days to weeks are needed for serotonin levels to reach steady-state. We show escitalopram's chemical efficacy is diminished under inflammation. Our model thus offers mechanisms for how chronic escitalopram affects brain serotonin, emphasizing the importance of optimized dose and time for future antidepressant discoveries.
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Affiliation(s)
- Sergio Mena
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | | | - Janet Best
- Department of Mathematics, The Ohio State University, Columbus, OH, USA
| | - H F Nijhout
- Department of Biology, Duke University, Durham, NC, USA
| | - Michael C Reed
- Department of Mathematics, Duke University, Durham, NC, USA
| | - Parastoo Hashemi
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK.
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15
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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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16
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Chen N, Xia Y, Wu W, Chen S, Zhao M, Song Y, Liu Y. Exploring the mechanism of agarwood moxa smoke in treating sleep disorders based on GC-MS and network pharmacology. Front Med (Lausanne) 2024; 11:1400334. [PMID: 38784223 PMCID: PMC11114445 DOI: 10.3389/fmed.2024.1400334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 04/18/2024] [Indexed: 05/25/2024] Open
Abstract
Background Agarwood moxibustion is a folk therapy developed by individuals of the Li nationality in China. There is evidence that agarwood moxa smoke (AMS) generated during agarwood moxibustion therapy can treat sleep disorders via traditional Chinese medicines' multiple target and pathway characteristics. However, the specific components and mechanisms involved have yet to be explored. Objective GC-MS (Gas Chromatography-Mass Spectrometry) and network pharmacology were used to investigate AMS's molecular basis and mechanism in treating sleep deprivation. Method GC-MS was used to determine the chemical composition of AMS; component target information was collected from TCMSP (Traditional Chinese Medicine Systems Pharmacology), PubChem (Public Chemical Database), GeneCards (Human Gene Database), and DisGeNet (Database of Genes and Diseases) were used to identify disease targets, and JVenn (Joint Venn) was used to identify the common targets of AMS and sleep disorders. STRING was used to construct a protein interaction network, Cytoscape 3.9.1 was used to build a multilevel network diagram of the "core components-efficacy targets-action pathways," the targets were imported into Metascape and DAVID for GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses and Autodock was used for molecular docking. This research used a network pharmacology methodology to investigate the therapeutic potential of Agarwood Moxa Smoke (AMS) in treating sleep problems. Examining the target genes and chemical constituents of AMS offers insights into the molecular processes and targets of the disease. Result Nine active ingredients comprising anti-inflammatory substances and antioxidants, such as caryophyllene and p-cymene, found seven sleep-regulating signaling pathways and eight targets linked to sleep disorders. GC-MS was used to identify the 94 active ingredients in AMS, and the active ingredients had strong binding with the key targets. Key findings included active components with known medicinal properties, such as p-cymene, eucalyptol, and caryophyllene. An investigation of network pharmacology revealed seven signaling pathways for sleep regulation and eight targets linked to sleep disorders, shedding light on AMS's effectiveness in enhancing sleep quality. Conclusion AMS may alleviate sleep disorders by modulating cellular and synaptic signaling, controlling hormone and neurotransmitter pathways, etc. Understanding AMS's material basis and mechanism of action provides a foundation for future research on treating sleep disorders with AMS. According to the study, Agarwood Moxa Smoke (AMS) may improve sleep quality by modifying cellular and synaptic signaling pathways for those who suffer from sleep problems. This might lead to the development of innovative therapies with fewer side effects.
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Affiliation(s)
- Nianhong Chen
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou, China
- Hainan Provincial Key Laboratory of Resources Conservation and Development of Southern Medicine, Key Laboratory of State Administration of Traditional Chinese Medicine for Agarwood Sustainable Utilization, International Joint Research Center for Quality of Traditional Chinese Medicine, Haikou, China
| | - Yucheng Xia
- Hainan Provincial Key Laboratory of Resources Conservation and Development of Southern Medicine, Key Laboratory of State Administration of Traditional Chinese Medicine for Agarwood Sustainable Utilization, International Joint Research Center for Quality of Traditional Chinese Medicine, Haikou, China
- College of Traditional Chinese Medicine, Hainan Medical University, Haikou, China
| | - Weiyan Wu
- Chengmai County Hospital of Traditional Chinese Medicine, Haikou, China
| | - Siyu Chen
- Chengmai County Hospital of Traditional Chinese Medicine, Haikou, China
| | - Mingming Zhao
- College of Traditional Chinese Medicine, Hainan Medical University, Haikou, China
| | - Yanting Song
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou, China
| | - Yangyang Liu
- Hainan Provincial Key Laboratory of Resources Conservation and Development of Southern Medicine, Key Laboratory of State Administration of Traditional Chinese Medicine for Agarwood Sustainable Utilization, International Joint Research Center for Quality of Traditional Chinese Medicine, Haikou, China
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17
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Hellsberg E, Boytsov D, Chen Q, Niello M, Freissmuth M, Rudnick G, Zhang YW, Sandtner W, Forrest LR. Identification of the potassium-binding site in serotonin transporter. Proc Natl Acad Sci U S A 2024; 121:e2319384121. [PMID: 38652746 PMCID: PMC11067047 DOI: 10.1073/pnas.2319384121] [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: 11/08/2023] [Accepted: 03/11/2024] [Indexed: 04/25/2024] Open
Abstract
Clearance of serotonin (5-hydroxytryptamine, 5-HT) from the synaptic cleft after neuronal signaling is mediated by serotonin transporter (SERT), which couples this process to the movement of a Na+ ion down its chemical gradient. After release of 5-HT and Na+ into the cytoplasm, the transporter faces a rate-limiting challenge of resetting its conformation to be primed again for 5-HT and Na+ binding. Early studies of vesicles containing native SERT revealed that K+ gradients can provide an additional driving force, via K+ antiport. Moreover, under appropriate conditions, a H+ ion can replace K+. Intracellular K+ accelerates the resetting step. Structural studies of SERT have identified two binding sites for Na+ ions, but the K+ site remains enigmatic. Here, we show that K+ antiport can drive substrate accumulation into vesicles containing SERT extracted from a heterologous expression system, allowing us to study the residues responsible for K+ binding. To identify candidate binding residues, we examine many cation binding configurations using molecular dynamics simulations, predicting that K+ binds to the so-called Na2 site. Site-directed mutagenesis of residues in this site can eliminate the ability of both K+ and H+ to drive 5-HT accumulation into vesicles and, in patch clamp recordings, prevent the acceleration of turnover rates and the formation of a channel-like state by K+ or H+. In conclusion, the Na2 site plays a pivotal role in orchestrating the sequential binding of Na+ and then K+ (or H+) ions to facilitate 5-HT uptake in SERT.
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Affiliation(s)
- Eva Hellsberg
- Computational Structural Biology Section, National Institutes of Neurological Disorders and Stroke, NIH, Bethesda, MD20892
| | - Danila Boytsov
- Center of Physiology and Pharmacology, Department of Pharmacology, Medical University of Vienna, Vienna1090, Austria
| | - Qingyang Chen
- School of Life Sciences, Higher Education Mega Center, Guangzhou University, Guangzhou510006, China
| | - Marco Niello
- Center of Physiology and Pharmacology, Department of Pharmacology, Medical University of Vienna, Vienna1090, Austria
| | - Michael Freissmuth
- Center of Physiology and Pharmacology, Department of Pharmacology, Medical University of Vienna, Vienna1090, Austria
| | - Gary Rudnick
- Department of Pharmacology, Yale University, New Haven, CT06510
| | - Yuan-Wei Zhang
- School of Life Sciences, Higher Education Mega Center, Guangzhou University, Guangzhou510006, China
| | - Walter Sandtner
- Center of Physiology and Pharmacology, Department of Pharmacology, Medical University of Vienna, Vienna1090, Austria
| | - Lucy R. Forrest
- Computational Structural Biology Section, National Institutes of Neurological Disorders and Stroke, NIH, Bethesda, MD20892
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18
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Hutchinson K, Schlessinger A. Comprehensive Characterization of LAT1 Cholesterol-Binding Sites. J Chem Theory Comput 2024; 20:3349-3358. [PMID: 38597304 DOI: 10.1021/acs.jctc.3c01391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
The human L-type amino acid transporter 1 (LAT1; SLC7A5), is an amino acid exchanger protein, primarily found in the blood-brain barrier, placenta, and testis, where it plays a key role in amino acid homeostasis. Cholesterol is an essential lipid that has been highlighted to play a role in regulating the activity of membrane transporters, such as LAT1, yet little is known about the molecular mechanisms driving this phenomenon. Here we perform a comprehensive computational analysis to investigate cholesterol's role in LAT1 structure and function, focusing on four cholesterol-binding sites (CHOL1-4) identified in a recent LAT1-apo inward-open conformation cryo-EM structure. Through a series of independent molecular dynamics (MD) simulations, molecular docking, MM/GBSA free energy calculations, and other analysis tools, we explored the interactions between LAT1 and cholesterol. Our findings suggest that CHOL3 forms the most stable and favorable interactions with LAT1. Principal component analysis (PCA) and center of mass (COM) distance assessments show that CHOL3 binding stabilizes the inward-open state of LAT1 by preserving the spatial arrangement of the hash and bundle domains. Additionally, we propose an alternative cholesterol-binding site for originally assigned CHOL1. Overall, this study improves the understanding of cholesterol's modulatory effect on LAT1 and proposes candidate sites for the discovery of future allosteric ligands with rational design.
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Affiliation(s)
- Keino Hutchinson
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Avner Schlessinger
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Department of Artificial Intelligence and Human Health, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
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19
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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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20
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Wei Y, Li R, Meng Y, Hu T, Zhao J, Gao Y, Bai Q, Li N, Zhao Y. Transport mechanism and pharmacology of the human GlyT1. Cell 2024; 187:1719-1732.e14. [PMID: 38513663 DOI: 10.1016/j.cell.2024.02.026] [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: 10/02/2023] [Revised: 12/09/2023] [Accepted: 02/21/2024] [Indexed: 03/23/2024]
Abstract
The glycine transporter 1 (GlyT1) plays a crucial role in the regulation of both inhibitory and excitatory neurotransmission by removing glycine from the synaptic cleft. Given its close association with glutamate/glycine co-activated NMDA receptors (NMDARs), GlyT1 has emerged as a central target for the treatment of schizophrenia, which is often linked to hypofunctional NMDARs. Here, we report the cryo-EM structures of GlyT1 bound with substrate glycine and drugs ALX-5407, SSR504734, and PF-03463275. These structures, captured at three fundamental states of the transport cycle-outward-facing, occluded, and inward-facing-enable us to illustrate a comprehensive blueprint of the conformational change associated with glycine reuptake. Additionally, we identified three specific pockets accommodating drugs, providing clear insights into the structural basis of their inhibitory mechanism and selectivity. Collectively, these structures offer significant insights into the transport mechanism and recognition of substrate and anti-schizophrenia drugs, thus providing a platform to design small molecules to treat schizophrenia.
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Affiliation(s)
- Yiqing Wei
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Renjie Li
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yufei Meng
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tuo Hu
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Zhao
- Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, Shandong 261000, China
| | - Yiwei Gao
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qinru Bai
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Na Li
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China
| | - Yan Zhao
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
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21
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Abstract
The vesicular monoamine transporter 2 (VMAT2) is a proton-dependent antiporter responsible for loading monoamine neurotransmitters into synaptic vesicles. Dysregulation of VMAT2 can lead to several neuropsychiatric disorders including Parkinson's disease and schizophrenia. Furthermore, drugs such as amphetamine and MDMA are known to act on VMAT2, exemplifying its role in the mechanisms of actions for drugs of abuse. Despite VMAT2's importance, there remains a critical lack of mechanistic understanding, largely driven by a lack of structural information. Here, we report a 3.1 Å resolution cryo-electron microscopy (cryo-EM) structure of VMAT2 complexed with tetrabenazine (TBZ), a non-competitive inhibitor used in the treatment of Huntington's chorea. We find TBZ interacts with residues in a central binding site, locking VMAT2 in an occluded conformation and providing a mechanistic basis for non-competitive inhibition. We further identify residues critical for cytosolic and lumenal gating, including a cluster of hydrophobic residues which are involved in a lumenal gating strategy. Our structure also highlights three distinct polar networks that may determine VMAT2 conformational dynamics and play a role in proton transduction. The structure elucidates mechanisms of VMAT2 inhibition and transport, providing insights into VMAT2 architecture, function, and the design of small-molecule therapeutics.
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Affiliation(s)
- Michael P Dalton
- Department of Structural Biology, University of PittsburghPittsburghUnited States
| | - Mary Hongying Cheng
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook UniversityStony BrookUnited States
| | - Ivet Bahar
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook UniversityStony BrookUnited States
| | - Jonathan A Coleman
- Department of Structural Biology, University of PittsburghPittsburghUnited States
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22
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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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23
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Tu G, Fu T, Zheng G, Xu B, Gou R, Luo D, Wang P, Xue W. Computational Chemistry in Structure-Based Solute Carrier Transporter Drug Design: Recent Advances and Future Perspectives. J Chem Inf Model 2024; 64:1433-1455. [PMID: 38294194 DOI: 10.1021/acs.jcim.3c01736] [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: 02/01/2024]
Abstract
Solute carrier transporters (SLCs) are a class of important transmembrane proteins that are involved in the transportation of diverse solute ions and small molecules into cells. There are approximately 450 SLCs within the human body, and more than a quarter of them are emerging as attractive therapeutic targets for multiple complex diseases, e.g., depression, cancer, and diabetes. However, only 44 unique transporters (∼9.8% of the SLC superfamily) with 3D structures and specific binding sites have been reported. To design innovative and effective drugs targeting diverse SLCs, there are a number of obstacles that need to be overcome. However, computational chemistry, including physics-based molecular modeling and machine learning- and deep learning-based artificial intelligence (AI), provides an alternative and complementary way to the classical drug discovery approach. Here, we present a comprehensive overview on recent advances and existing challenges of the computational techniques in structure-based drug design of SLCs from three main aspects: (i) characterizing multiple conformations of the proteins during the functional process of transportation, (ii) identifying druggability sites especially the cryptic allosteric ones on the transporters for substrates and drugs binding, and (iii) discovering diverse small molecules or synthetic protein binders targeting the binding sites. This work is expected to provide guidelines for a deep understanding of the structure and function of the SLC superfamily to facilitate rational design of novel modulators of the transporters with the aid of state-of-the-art computational chemistry technologies including artificial intelligence.
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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
| | - Tingting Fu
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | | | - Binbin Xu
- Chengdu Sintanovo Biotechnology Co., Ltd., Chengdu 610200, 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
| | - Panpan Wang
- College of Chemistry and Pharmaceutical Engineering, Huanghuai University, Zhumadian 463000, 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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24
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Shinozuka K, Tabaac BJ, Arenas A, Beutler BD, Cherian K, Evans VD, Fasano C, Muir OS. Psychedelic Therapy: A Primer for Primary Care Clinicians-3,4-Methylenedioxy-methamphetamine (MDMA). Am J Ther 2024; 31:e141-e154. [PMID: 38518271 DOI: 10.1097/mjt.0000000000001722] [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: 03/24/2024]
Abstract
BACKGROUND After becoming notorious for its use as a party drug in the 1980s, 3,4-methylenedioxy-methampetamine (MDMA), also known by its street names "molly" and "ecstasy," has emerged as a powerful treatment for post-traumatic stress disorder (PTSD). AREAS OF UNCERTAINTY There are extensive data about the risk profile of MDMA. However, the literature is significantly biased. Animal models demonstrating neurotoxic or adverse effects used doses well beyond the range that would be expected in humans (up to 40 mg/kg in rats compared with roughly 1-2 mg/kg in humans). Furthermore, human samples often comprise recreational users who took other substances in addition to MDMA, in uncontrolled settings. THERAPEUTIC ADVANCES Phase III clinical trials led by the Multidisciplinary Association for Psychedelic Studies (MAPS) have shown that MDMA-assisted psychotherapy has an effect size of d = 0.7-0.91, up to 2-3 times higher than the effect sizes of existing antidepressant treatments. 67%-71% of patients who undergo MDMA-assisted psychotherapy no longer meet the diagnostic criteria for PTSD within 18 weeks. We also describe other promising applications of MDMA-assisted psychotherapy for treating alcohol use disorder, social anxiety, and other psychiatric conditions. LIMITATIONS Thus far, almost all clinical trials on MDMA have been sponsored by a single organization, MAPS. More work is needed to determine whether MDMA-assisted therapy is more effective than existing nonpharmacological treatments such as cognitive behavioral therapy. CONCLUSIONS Phase III trials suggest that MDMA is superior to antidepressant medications for treating PTSD. Now that MAPS has officially requested the Food and Drug Administration to approve MDMA as a treatment for PTSD, legal MDMA-assisted therapy may become available as soon as 2024.
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Affiliation(s)
- Kenneth Shinozuka
- Centre for Eudaimonia and Human Flourishing, University of Oxford, Oxford, United Kingdom
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Burton J Tabaac
- University of Nevada, Reno School of Medicine, Reno, NV
- Department of Neurology, Carson Tahoe Health, Carson City, NV
| | - Alejandro Arenas
- Department of Anesthesiology, University of Washington School of Medicine, Seattle, WA
| | - Bryce D Beutler
- University of Southern California, Keck School of Medicine, Los Angeles, CA
| | - Kirsten Cherian
- Department of Psychiatry & Behavioral Sciences, Stanford University, Palo Alto, CA
| | - Viviana D Evans
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY
| | | | - Owen S Muir
- Fermata Health, Brooklyn, NY; and
- Acacia Clinics, Sunnyvale, CA
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25
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Vaughan RA, Henry LK, Foster JD, Brown CR. Post-translational mechanisms in psychostimulant-induced neurotransmitter efflux. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2024; 99:1-33. [PMID: 38467478 DOI: 10.1016/bs.apha.2023.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
The availability of monoamine neurotransmitters in the brain is under the control of dopamine, norepinephrine, and serotonin transporters expressed on the plasma membrane of monoaminergic neurons. By regulating transmitter levels these proteins mediate crucial functions including cognition, attention, and reward, and dysregulation of their activity is linked to mood and psychiatric disorders of these systems. Amphetamine-based transporter substrates stimulate non-exocytotic transmitter efflux that induces psychomotor stimulation, addiction, altered mood, hallucinations, and psychosis, thus constituting a major component of drug neurochemical and behavioral outcomes. Efflux is under the control of transporter post-translational modifications that synergize with other regulatory events, and this review will summarize our knowledge of these processes and their role in drug mechanisms.
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Affiliation(s)
- Roxanne A Vaughan
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States.
| | - L Keith Henry
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - James D Foster
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Christopher R Brown
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
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26
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Dalton MP, Cheng MH, Bahar I, Coleman JA. Structural mechanisms for VMAT2 inhibition by tetrabenazine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.05.556211. [PMID: 37732203 PMCID: PMC10508774 DOI: 10.1101/2023.09.05.556211] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
The vesicular monoamine transporter 2 (VMAT2) is a proton-dependent antiporter responsible for loading monoamine neurotransmitters into synaptic vesicles. Dysregulation of VMAT2 can lead to several neuropsychiatric disorders including Parkinson's disease and schizophrenia. Furthermore, drugs such as amphetamine and MDMA are known to act on VMAT2, exemplifying its role in the mechanisms of actions for drugs of abuse. Despite VMAT2's importance, there remains a critical lack of mechanistic understanding, largely driven by a lack of structural information. Here we report a 3.1 Å resolution cryo-EM structure of VMAT2 complexed with tetrabenazine (TBZ), a non-competitive inhibitor used in the treatment of Huntington's chorea. We find TBZ interacts with residues in a central binding site, locking VMAT2 in an occluded conformation and providing a mechanistic basis for non-competitive inhibition. We further identify residues critical for cytosolic and lumenal gating, including a cluster of hydrophobic residues which are involved in a lumenal gating strategy. Our structure also highlights three distinct polar networks that may determine VMAT2 conformational dynamics and play a role in proton transduction. The structure elucidates mechanisms of VMAT2 inhibition and transport, providing insights into VMAT2 architecture, function, and the design of small-molecule therapeutics.
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Affiliation(s)
- Michael P Dalton
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Mary Hongying Cheng
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Ivet Bahar
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Jonathan A Coleman
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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27
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Drew D, Boudker O. Ion and lipid orchestration of secondary active transport. Nature 2024; 626:963-974. [PMID: 38418916 DOI: 10.1038/s41586-024-07062-3] [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: 06/27/2023] [Accepted: 01/12/2024] [Indexed: 03/02/2024]
Abstract
Transporting small molecules across cell membranes is an essential process in cell physiology. Many structurally diverse, secondary active transporters harness transmembrane electrochemical gradients of ions to power the uptake or efflux of nutrients, signalling molecules, drugs and other ions across cell membranes. Transporters reside in lipid bilayers on the interface between two aqueous compartments, where they are energized and regulated by symported, antiported and allosteric ions on both sides of the membrane and the membrane bilayer itself. Here we outline the mechanisms by which transporters couple ion and solute fluxes and discuss how structural and mechanistic variations enable them to meet specific physiological needs and adapt to environmental conditions. We then consider how general bilayer properties and specific lipid binding modulate transporter activity. Together, ion gradients and lipid properties ensure the effective transport, regulation and distribution of small molecules across cell membranes.
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Affiliation(s)
- David Drew
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
| | - Olga Boudker
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA.
- Howard Hughes Medical Institute, Weill Cornell Medicine, New York, NY, USA.
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28
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Li J, Yao X, Wu Y, Wang C, Yang J, Wu C. The anticonvulsant effect of saiga horn on febrile seizures by regulating brain serotonin content and inhibiting neuroinflammation. JOURNAL OF ETHNOPHARMACOLOGY 2024; 319:117180. [PMID: 37709104 DOI: 10.1016/j.jep.2023.117180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/05/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Saiga antelope horn (SAH) is derived from the Saiga antelope (Saiga tatarica Linnaeus) of the bovidae family. SAH has been used for the treatment of febrile seizures (FS) in children for thousands of years in China. Due to the biological protection of Saiga antelope and its ethical reasons, the application of SAH has been widely restricted. Unfortunately, the field of artificial manufacturing of SAH is still blank at present. The mechanism of SAH in the treatment of FS is still unclear, which seriously hinders the further development of artificial antelope horns and the search for substitutes for SAH. At present, there is an urgent need to determine the mechanism of SAH in the treatment of FS, so as to provide a theoretical basis for artificial antelope horn and its substitutes. AIM OF THE STUDY To explore the anti-FS effect of natural SAH on FS rat model and its possible mechanism, and to provide a theoretical basis for the subsequent manufacture of artificial antelope horns and the search for the best substitutes. MATERIALS AND METHODS FS was induced by a warm water bath (48 ± 0.5 °C). The latency and seizure grade of FS were observed and recorded. Hematoxylin-eosin (HE) staining was used to observe the functional defect of hippocampal cells. The contents of tryptophan (TRP), serotonin (5-HT), IL-1β and TNF-a in rat brain tissue were determined by ELISA. qRT-PCR and Western blot were used to detect the expression of 5-HT synthesis related neurotransmitter receptors, catalytic enzymes and inflammatory factors in hippocampus. Immunofluorescence was used to observe the expression of TPH2 protein in the dorsal raphe nucleus of rat brain. RESULTS After pretreating rats with SAH, the seizure grade of FS was significantly reduced and the latency was prolonged. SAH can reduce the histological damage of hippocampal tissue induced by FS in rats. Further analysis of ELISA results showed that SAH significantly increased the levels of TRP and 5-HT in the brain of FS rats, and significantly decreased the levels of IL-1β and TNF-a. The results of QPCR showed that SAH could up-regulate the expression of ER-β and TPH2 mRNA and down-regulate the expression of IL-1β and TNF-ɑ mRNA in the hippocampus of rats. In addition, WB and immunofluorescence results showed that SAH could significantly up-regulate the expression of ER-β/TPH2/5-HT pathway in the hippocampus of FS rats and the expression of TPH2 protein in the raphe nucleus, but had no significant effect on SERT protein in the hippocampus of FS rats. In addition, ER-β protein inhibitor PHTPP significantly inhibited the therapeutic effect of SAH on FS rats. CONCLUSIONS The present study demonstrates that SAH has a significant anticonvulsant effect on the FS rat model. The mechanism may be related to the increase of TRP content and up-regulation the expression of ER-β/TPH2/5-HT signaling pathway in the brain of FS rats, thereby increasing the content of 5-HT in the brain and reducing the content of IL-1β and TNF-a in the brain.
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Affiliation(s)
- Jinhu Li
- School of Pharmacy/School of Modern Chinese Medicine Industry, Chengdu University of Traditional Chinese Medicine, China.
| | - Xiang Yao
- School of Pharmacy/School of Modern Chinese Medicine Industry, Chengdu University of Traditional Chinese Medicine, China.
| | - Yurou Wu
- School of Pharmacy/School of Modern Chinese Medicine Industry, Chengdu University of Traditional Chinese Medicine, China.
| | - Chengwei Wang
- School of Pharmacy/School of Modern Chinese Medicine Industry, Chengdu University of Traditional Chinese Medicine, China.
| | - Jincheng Yang
- School of Pharmacy/School of Modern Chinese Medicine Industry, Chengdu University of Traditional Chinese Medicine, China.
| | - Chunjie Wu
- Innovative Institute of Chinese Medicine and Pharmacy/Academy for Interdiscipline, Chengdu University of Traditional Chinese Medicine, China; Sichuan Engineering Research Center for Endangered Medicinal Animals, China.
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29
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Schmidt SG, Nygaard A, Mindell JA, Loland CJ. Exploring the K + binding site and its coupling to transport in the neurotransmitter:sodium symporter LeuT. eLife 2024; 12:RP87985. [PMID: 38271216 PMCID: PMC10945697 DOI: 10.7554/elife.87985] [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] [Indexed: 01/27/2024] Open
Abstract
The neurotransmitter:sodium symporters (NSSs) are secondary active transporters that couple the reuptake of substrate to the symport of one or two sodium ions. One bound Na+ (Na1) contributes to the substrate binding, while the other Na+ (Na2) is thought to be involved in the conformational transition of the NSS. Two NSS members, the serotonin transporter (SERT) and the Drosophila dopamine transporter (dDAT), also couple substrate uptake to the antiport of K+ by a largely undefined mechanism. We have previously shown that the bacterial NSS homologue, LeuT, also binds K+, and could therefore serve as a model protein for the exploration of K+ binding in NSS proteins. Here, we characterize the impact of K+ on substrate affinity and transport as well as on LeuT conformational equilibrium states. Both radioligand binding assays and transition metal ion FRET (tmFRET) yielded similar K+ affinities for LeuT. K+ binding was specific and saturable. LeuT reconstituted into proteoliposomes showed that intra-vesicular K+ dose-dependently increased the transport velocity of [3H]alanine, whereas extra-vesicular K+ had no apparent effect. K+ binding induced a LeuT conformation distinct from the Na+- and substrate-bound conformation. Conservative mutations of the Na1 site residues affected the binding of Na+ and K+ to different degrees. The Na1 site mutation N27Q caused a >10-fold decrease in K+ affinity but at the same time a ~3-fold increase in Na+ affinity. Together, the results suggest that K+ binding to LeuT modulates substrate transport and that the K+ affinity and selectivity for LeuT is sensitive to mutations in the Na1 site, pointing toward the Na1 site as a candidate site for facilitating the interaction with K+ in some NSSs.
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Affiliation(s)
- Solveig G Schmidt
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Nygaard
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Joseph A Mindell
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Claus J Loland
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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30
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Gradisch R, Schlögl K, Lazzarin E, Niello M, Maier J, Mayer FP, Alves da Silva L, Skopec SMC, Blakely RD, Sitte HH, Mihovilovic MD, Stockner T. Ligand coupling mechanism of the human serotonin transporter differentiates substrates from inhibitors. Nat Commun 2024; 15:417. [PMID: 38195746 PMCID: PMC10776687 DOI: 10.1038/s41467-023-44637-6] [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: 07/17/2023] [Accepted: 12/22/2023] [Indexed: 01/11/2024] Open
Abstract
The presynaptic serotonin transporter (SERT) clears extracellular serotonin following vesicular release to ensure temporal and spatial regulation of serotonergic signalling and neurotransmitter homeostasis. Prescription drugs used to treat neurobehavioral disorders, including depression, anxiety, and obsessive-compulsive disorder, trap SERT by blocking the transport cycle. In contrast, illicit drugs of abuse like amphetamines reverse SERT directionality, causing serotonin efflux. Both processes result in increased extracellular serotonin levels. By combining molecular dynamics simulations with biochemical experiments and using a homologous series of serotonin analogues, we uncovered the coupling mechanism between the substrate and the transporter, which triggers the uptake of serotonin. Free energy analysis showed that only scaffold-bound substrates could initiate SERT occlusion through attractive long-range electrostatic interactions acting on the bundle domain. The associated spatial requirements define substrate and inhibitor properties, enabling additional possibilities for rational drug design approaches.
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Affiliation(s)
- Ralph Gradisch
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Katharina Schlögl
- TU Wien, Institute of Applied Synthetic Chemistry, Getreidemarkt 9, 1060, Vienna, Austria
| | - Erika Lazzarin
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Marco Niello
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
- Genetics of Cognition Laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Julian Maier
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Felix P Mayer
- Florida Atlantic University, Department of Biomedical Science, Jupiter, FL, 33458, USA
- Stiles-Nicholson Brain Institute, Jupiter, FL, 33458, USA
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark
| | - Leticia Alves da Silva
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Sophie M C Skopec
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Randy D Blakely
- Florida Atlantic University, Department of Biomedical Science, Jupiter, FL, 33458, USA
- Stiles-Nicholson Brain Institute, Jupiter, FL, 33458, USA
| | - Harald H Sitte
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
- Al-Ahliyya Amman University, Hourani Center for Applied Scientific Research, Amman, Jordan
- Medical University of Vienna, Center for Addiction Research and Science, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Marko D Mihovilovic
- TU Wien, Institute of Applied Synthetic Chemistry, Getreidemarkt 9, 1060, Vienna, Austria
| | - Thomas Stockner
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria.
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31
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O’Connell CJ, Brown RS, Peach TM, Traubert OD, Schwierling HC, Notorgiacomo GA, Robson MJ. Strain in the Midbrain: Impact of Traumatic Brain Injury on the Central Serotonin System. Brain Sci 2024; 14:51. [PMID: 38248266 PMCID: PMC10813794 DOI: 10.3390/brainsci14010051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/20/2023] [Accepted: 01/02/2024] [Indexed: 01/23/2024] Open
Abstract
Traumatic brain injury (TBI) is a pervasive public health crisis that severely impacts the quality of life of affected individuals. Like peripheral forms of trauma, TBI results from extraordinarily heterogeneous environmental forces being imparted on the cranial space, resulting in heterogeneous disease pathologies. This has made therapies for TBI notoriously difficult to develop, and currently, there are no FDA-approved pharmacotherapies specifically for the acute or chronic treatment of TBI. TBI is associated with changes in cognition and can precipitate the onset of debilitating psychiatric disorders like major depressive disorder (MDD), generalized anxiety disorder (GAD), and post-traumatic stress disorder (PTSD). Complicating these effects of TBI, FDA-approved pharmacotherapies utilized to treat these disorders often fail to reach the desired level of efficacy in the context of neurotrauma. Although a complicated association, decades of work have linked central serotonin (5-HT) neurotransmission as being involved in the etiology of a myriad of neuropsychiatric disorders, including MDD and GAD. 5-HT is a biogenic monoamine neurotransmitter that is highly conserved across scales of biology. Though the majority of 5-HT is isolated to peripheral sites such as the gastrointestinal (GI) tract, 5-HT neurotransmission within the CNS exerts exquisite control over diverse biological functions, including sleep, appetite and respiration, while simultaneously establishing normal mood, perception, and attention. Although several key studies have begun to elucidate how various forms of neurotrauma impact central 5-HT neurotransmission, a full determination of precisely how TBI disrupts the highly regulated dynamics of 5-HT neuron function and/or 5-HT neurotransmission has yet to be conceptually or experimentally resolved. The purpose of the current review is, therefore, to integrate the disparate bodies of 5-HT and TBI research and synthesize insight into how new combinatorial research regarding 5-HT neurotransmission and TBI may offer an informed perspective into the nature of TBI-induced neuropsychiatric complications.
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Affiliation(s)
- Christopher J. O’Connell
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; (C.J.O.); (R.S.B.); (T.M.P.)
| | - Ryan S. Brown
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; (C.J.O.); (R.S.B.); (T.M.P.)
| | - Taylor M. Peach
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; (C.J.O.); (R.S.B.); (T.M.P.)
| | - Owen D. Traubert
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA;
| | - Hana C. Schwierling
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; (C.J.O.); (R.S.B.); (T.M.P.)
| | | | - Matthew J. Robson
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; (C.J.O.); (R.S.B.); (T.M.P.)
- Neuroscience Graduate Program, College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
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32
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Pearson K, Beier K, Mardis T, Munoz B, Zaidi A. The Neurochemistry of Depression: The Good, The Bad and The Ugly. MISSOURI MEDICINE 2024; 121:68-75. [PMID: 38404431 PMCID: PMC10887465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
A large constellation of experimental evidence suggests that neuroinflammation is involved in the onset of depression and neurodegenerative disorders. Many studies have shown impairments in tryptophan metabolism, the major pathway for the synthesis of serotonin, the mood regulating neurotransmitter. This article reviews the various metabolites generated in the competing pathways of tryptophan metabolism including the kynurenine pathway. Increased synthesis of the neurotoxic compound quinolinic acid occurs at the expense of the synthesis of the neuroprotective metabolite kynurenic acid. This shift in equilibrium plays a critical role in the induction of oxidative stress, neuroinflammation, and neurotoxicity. Sufficient protein intake with adequate amounts of tryptophan along with dietary antioxidants and flavonoids may offer protection against major depressive and neurodegenerative disorders.
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Affiliation(s)
- Kami Pearson
- Research Associate, Kansas City University, Kansas City, Missouri
| | - Kimberley Beier
- Medical student, Kansas City University, Kansas City, Missouri
| | - Thornton Mardis
- Medical student, Kansas City University, Kansas City, Missouri
| | - Bryan Munoz
- Medical student, Kansas City University, Kansas City, Missouri
| | - Asma Zaidi
- Professor of Biochemistry, Kansas City University, Kansas City, Missouri
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33
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Karmakar S, Lal G. Role of Serotonergic System in Regulating Brain Tumor-Associated Neuroinflammatory Responses. Methods Mol Biol 2024; 2761:181-207. [PMID: 38427238 DOI: 10.1007/978-1-0716-3662-6_14] [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] [Indexed: 03/02/2024]
Abstract
Serotonin signaling regulates wide arrays of both neural and extra-neural functions. Serotonin is also found to affect cancer progression directly as well as indirectly by modulating the immune cells. In the brain, serotonin plays a key role in regulating various functions; disturbance of the normal activities of serotonin leads to various mental illnesses, including the neuroinflammatory response in the central nervous system (CNS). The neuroinflammatory response can be initiated in various psychological illnesses and brain cancer. Serotonergic signaling can impact the functions of both glial as well as the immune cells. It can also affect the tumor immune microenvironment and the inflammatory response associated with brain cancers. Apart from this, many drugs used for treatment of psychological illness are known to modulate serotonergic system and can cross the blood-brain barrier. Understanding the role of serotonergic pathways in regulating neuroinflammatory response and brain cancer will provide a new paradigm in modulating the serotonergic components in treating brain cancer and associated inflammation-induced brain damages.
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Affiliation(s)
- Surojit Karmakar
- National Centre for Cell Science (NCCS), SPPU Campus, Ganeshkhind, Pune, Maharashtra, India
| | - Girdhari Lal
- National Centre for Cell Science (NCCS), SPPU Campus, Ganeshkhind, Pune, Maharashtra, India.
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34
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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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35
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Wang X, Che F, Zhang X, Li P, Zhang W, Tang B. Tracing Superoxide Anion in Serotonergic Neurons of Living Mouse Brains with Depression by Small-Molecule Fluorescence Probes. Anal Chem 2023; 95:15614-15620. [PMID: 37830753 DOI: 10.1021/acs.analchem.3c02701] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
In brains, the serotonergic neurons are the unique resource of the neurotransmitter serotonin, which plays a pivotal role in the physiology of the brain. The dysfunction of serotonergic neurons caused by oxidative stress in the brain is closely related to the occurrence and development of various mental diseases, such as depression. As the biomarker of oxidative stress, the superoxide anion radical (O2•-) can cause oxidative damage to proteins, nucleic acids and lipids, disturbing the function of neurons and brains. A serotonin transporter (SERT) specifically expresses in serotonergic neurons, which is the biomarker of serotonergic neurons. Thus, we created two novel small molecular fluorescent probes (PA-CA and HT-CA) for imaging O2•- in serotonergic neurons of living brains of mice based on specific targeting groups of SERT. Both PA-CA and HT-CA exert excellent SERT-targetable and glorious selectivity for O2•-. Those two probes could monitor the boost of O2•- in living hsert-HEK293 cells that specifically express SERT under oxidative stress. With two-photon fluorescence imaging, we revealed for the first time that O2•- is significantly increased in serotonergic neurons in living brains of mice with depression. More importantly, proteomic analyses suggested that O2•- could oxidize cysteine and histidine in the active site of SERT, which is involved in the development of depression. This work provides new materials for living brain imaging and offers new strategy for unraveling the pathophysiology of depression.
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Affiliation(s)
- Xin Wang
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, Shandong People's Republic of China
| | - Feida Che
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, Shandong People's Republic of China
| | - Xin Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, Shandong People's Republic of China
| | - Ping Li
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, Shandong People's Republic of China
| | - Wen Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, Shandong People's Republic of China
| | - Bo Tang
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, Shandong People's Republic of China
- Laoshan Laboratory, Qingdao 266237, ShandongPeople's Republic of China
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36
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Salomon K, Abramyan AM, Plenge P, Wang L, Bundgaard C, Bang-Andersen B, Loland CJ, Shi L. Dynamic extracellular vestibule of human SERT: Unveiling druggable potential with high-affinity allosteric inhibitors. Proc Natl Acad Sci U S A 2023; 120:e2304089120. [PMID: 37792512 PMCID: PMC10576121 DOI: 10.1073/pnas.2304089120] [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: 03/13/2023] [Accepted: 08/15/2023] [Indexed: 10/06/2023] Open
Abstract
The serotonin transporter (SERT) tightly regulates synaptic serotonin levels and has been the primary target of antidepressants. Binding of inhibitors to the allosteric site of human SERT (hSERT) impedes the dissociation of antidepressants bound at the central site and may enhance the efficacy of such antidepressants to potentially reduce their dosage and side effects. Here, we report the identification of a series of high-affinity allosteric inhibitors of hSERT in a unique scaffold, with the lead compound, Lu AF88273 (3-(1-(2-(1H-indol-3-yl)ethyl)piperidin-4-yl)-6-chloro-1H-indole), having 2.1 nM allosteric potency in inhibiting imipramine dissociation. In addition, we find that Lu AF88273 also inhibits serotonin transport in a noncompetitive manner. The binding pose of Lu AF88273 in the allosteric site of hSERT is determined with extensive molecular dynamics simulations and rigorous absolute binding free energy perturbation (FEP) calculations, which show that a part of the compound occupies a dynamically formed small cavity. The predicted binding location and pose are validated by site-directed mutagenesis and can explain much of the structure-activity relationship of these inhibitors using the relative binding FEP calculations. Together, our findings provide a promising lead compound and the structural basis for the development of allosteric drugs targeting hSERT. Further, they demonstrate that the divergent allosteric sites of neurotransmitter transporters can be selectively targeted.
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Affiliation(s)
- Kristine Salomon
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Ara M. Abramyan
- Computational Chemistry and Molecular Biophysics Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, NIH, Baltimore, MD21224
- Schrödinger, Inc., San Diego, CA92121
| | - Per Plenge
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | | | - Christoffer Bundgaard
- Medicinal Chemistry and Translational DMPK, H. Lundbeck A/S, DK-2500Copenhagen-Valby, Denmark
| | - Benny Bang-Andersen
- Medicinal Chemistry and Translational DMPK, H. Lundbeck A/S, DK-2500Copenhagen-Valby, Denmark
| | - Claus J. Loland
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Lei Shi
- Computational Chemistry and Molecular Biophysics Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, NIH, Baltimore, MD21224
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37
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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: 1] [Impact Index Per Article: 1.0] [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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38
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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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Zhu A, Huang J, Kong F, Tan J, Lei J, Yuan Y, Yan C. Molecular basis for substrate recognition and transport of human GABA transporter GAT1. Nat Struct Mol Biol 2023:10.1038/s41594-023-00983-z. [PMID: 37400655 DOI: 10.1038/s41594-023-00983-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 03/31/2023] [Indexed: 07/05/2023]
Abstract
γ-Aminobutyric acid (GABA), an important inhibitory neurotransmitter in the central nervous system, is recycled through specific GABA transporters (GATs). GAT1, which is mainly expressed in the presynaptic terminals of axons, is a potential drug target of neurological disorders due to its essential role in GABA transport. Here we report four cryogenic electron microscopy structures of human GAT1, at resolutions of 2.2-3.2 Å. GAT1 in substrate-free form or in complex with the antiepileptic drug tiagabine exhibits an inward-open conformation. In the presence of GABA or nipecotic acid, inward-occluded structures are captured. The GABA-bound structure reveals an interaction network bridged by hydrogen bonds and ion coordination for GABA recognition. The substrate-free structure unwinds the last helical turn of transmembrane helix TM1a to release sodium ions and substrate. Complemented by structure-guided biochemical analyses, our studies reveal detailed mechanism of GABA recognition and transport, and elucidate mode of action of the inhibitors, nipecotic acid and tiagabine.
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Affiliation(s)
- Angqi Zhu
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Junhao Huang
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Fang Kong
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jiaxin Tan
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jianlin Lei
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yafei Yuan
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
| | - Chuangye Yan
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
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40
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Nayak SR, Joseph D, Höfner G, Dakua A, Athreya A, Wanner KT, Kanner BI, Penmatsa A. Cryo-EM structure of GABA transporter 1 reveals substrate recognition and transport mechanism. Nat Struct Mol Biol 2023; 30:1023-1032. [PMID: 37400654 PMCID: PMC10352132 DOI: 10.1038/s41594-023-01011-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 05/04/2023] [Indexed: 07/05/2023]
Abstract
The inhibitory neurotransmitter γ-aminobutyric acid (GABA) is cleared from the synaptic cleft by the sodium- and chloride-coupled GABA transporter GAT1. Inhibition of GAT1 prolongs the GABAergic signaling at the synapse and is a strategy to treat certain forms of epilepsy. In this study, we present the cryo-electron microscopy structure of Rattus norvegicus GABA transporter 1 (rGAT1) at a resolution of 3.1 Å. The structure elucidation was facilitated by epitope transfer of a fragment-antigen binding (Fab) interaction site from the Drosophila dopamine transporter (dDAT) to rGAT1. The structure reveals rGAT1 in a cytosol-facing conformation, with a linear density in the primary binding site that accommodates a molecule of GABA, a displaced ion density proximal to Na site 1 and a bound chloride ion. A unique insertion in TM10 aids the formation of a compact, closed extracellular gate. Besides yielding mechanistic insights into ion and substrate recognition, our study will enable the rational design of specific antiepileptics.
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Affiliation(s)
| | - Deepthi Joseph
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
- Department of Molecular Biosciences, College of Natural Sciences, University of Texas at Austin, Austin, TX, USA
| | - Georg Höfner
- Department of Pharmacy, Center for Drug Research, Ludwig Maximilians University of Munich, Munich, Germany
| | - Archishman Dakua
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
- Biophysics Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Arunabh Athreya
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Klaus T Wanner
- Department of Pharmacy, Center for Drug Research, Ludwig Maximilians University of Munich, Munich, Germany
| | - Baruch I Kanner
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University, Hadassah Medical School, Jerusalem, Israel
| | - Aravind Penmatsa
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India.
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41
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Dvorak V, Superti-Furga G. Structural and functional annotation of solute carrier transporters: implication for drug discovery. Expert Opin Drug Discov 2023; 18:1099-1115. [PMID: 37563933 DOI: 10.1080/17460441.2023.2244760] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/01/2023] [Indexed: 08/12/2023]
Abstract
INTRODUCTION Solute carriers (SLCs) represent the largest group of membrane transporters in the human genome. They play a central role in controlling the compartmentalization of metabolism and most of this superfamily is linked to human disease. Despite being in general considered druggable and attractive therapeutic targets, many SLCs remain poorly annotated, both functionally and structurally. AREAS COVERED The aim of this review is to provide an overview of functional and structural parameters of SLCs that play important roles in their druggability. To do this, the authors provide an overview of experimentally solved structures of human SLCs, with emphasis on structures solved in complex with chemical modulators. From the functional annotations, the authors focus on SLC localization and SLC substrate annotations. EXPERT OPINION Recent progress in the structural and functional annotations allows to refine the SLC druggability index. Particularly the increasing number of experimentally solved structures of SLCs provides insights into mode-of-action of a significant number of chemical modulators of SLCs.
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Affiliation(s)
- Vojtech Dvorak
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - 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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42
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Radosavljevic M, Svob Strac D, Jancic J, Samardzic J. The Role of Pharmacogenetics in Personalizing the Antidepressant and Anxiolytic Therapy. Genes (Basel) 2023; 14:1095. [PMID: 37239455 PMCID: PMC10218654 DOI: 10.3390/genes14051095] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/12/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023] Open
Abstract
Pharmacotherapy for neuropsychiatric disorders, such as anxiety and depression, has been characterized by significant inter-individual variability in drug response and the development of side effects. Pharmacogenetics, as a key part of personalized medicine, aims to optimize therapy according to a patient's individual genetic signature by targeting genetic variations involved in pharmacokinetic or pharmacodynamic processes. Pharmacokinetic variability refers to variations in a drug's absorption, distribution, metabolism, and elimination, whereas pharmacodynamic variability results from variable interactions of an active drug with its target molecules. Pharmacogenetic research on depression and anxiety has focused on genetic polymorphisms affecting metabolizing cytochrome P450 (CYP) and uridine 5'-diphospho-glucuronosyltransferase (UGT) enzymes, P-glycoprotein ATP-binding cassette (ABC) transporters, and monoamine and γ-aminobutyric acid (GABA) metabolic enzymes, transporters, and receptors. Recent pharmacogenetic studies have revealed that more efficient and safer treatments with antidepressants and anxiolytics could be achieved through genotype-guided decisions. However, because pharmacogenetics cannot explain all observed heritable variations in drug response, an emerging field of pharmacoepigenetics investigates how epigenetic mechanisms, which modify gene expression without altering the genetic code, might influence individual responses to drugs. By understanding the epi(genetic) variability of a patient's response to pharmacotherapy, clinicians could select more effective drugs while minimizing the likelihood of adverse reactions and therefore improve the quality of treatment.
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Affiliation(s)
- Milica Radosavljevic
- Institute of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia;
| | - Dubravka Svob Strac
- Laboratory for Molecular Neuropsychiatry, Division of Molecular Medicine, Rudjer Boskovic Institute, 10000 Zagreb, Croatia;
| | - Jasna Jancic
- Clinic of Neurology and Psychiatry for Children and Youth, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia;
| | - Janko Samardzic
- Institute of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia;
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43
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Singh I, Seth A, Billesbølle CB, Braz J, Rodriguiz RM, Roy K, Bekele B, Craik V, Huang XP, Boytsov D, Pogorelov VM, Lak P, O'Donnell H, Sandtner W, Irwin JJ, Roth BL, Basbaum AI, Wetsel WC, Manglik A, Shoichet BK, Rudnick G. Structure-based discovery of conformationally selective inhibitors of the serotonin transporter. Cell 2023; 186:2160-2175.e17. [PMID: 37137306 PMCID: PMC10306110 DOI: 10.1016/j.cell.2023.04.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 02/05/2023] [Accepted: 04/06/2023] [Indexed: 05/05/2023]
Abstract
The serotonin transporter (SERT) removes synaptic serotonin and is the target of anti-depressant drugs. SERT adopts three conformations: outward-open, occluded, and inward-open. All known inhibitors target the outward-open state except ibogaine, which has unusual anti-depressant and substance-withdrawal effects, and stabilizes the inward-open conformation. Unfortunately, ibogaine's promiscuity and cardiotoxicity limit the understanding of inward-open state ligands. We docked over 200 million small molecules against the inward-open state of the SERT. Thirty-six top-ranking compounds were synthesized, and thirteen inhibited; further structure-based optimization led to the selection of two potent (low nanomolar) inhibitors. These stabilized an outward-closed state of the SERT with little activity against common off-targets. A cryo-EM structure of one of these bound to the SERT confirmed the predicted geometry. In mouse behavioral assays, both compounds had anxiolytic- and anti-depressant-like activity, with potencies up to 200-fold better than fluoxetine (Prozac), and one substantially reversed morphine withdrawal effects.
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Affiliation(s)
- Isha Singh
- Department of Pharmaceutical Chemistry, University of California, San Francisco, 1700 4th St., Byers Hall Suite 508D, San Francisco, CA 94143, USA
| | - Anubha Seth
- Department of Pharmacology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8066, USA
| | - Christian B Billesbølle
- Department of Pharmaceutical Chemistry, University of California, San Francisco, 1700 4th St., Byers Hall Suite 508D, San Francisco, CA 94143, USA
| | - Joao Braz
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ramona M Rodriguiz
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA; Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical Center, Durham, NC 27710, USA
| | - Kasturi Roy
- Department of Pharmacology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8066, USA
| | - Bethlehem Bekele
- Department of Pharmacology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8066, USA
| | - Veronica Craik
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Xi-Ping Huang
- Department of Pharmacology, NIMH Psychoactive Drug Screening Program, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Danila Boytsov
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Vladimir M Pogorelov
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA
| | - Parnian Lak
- Department of Pharmaceutical Chemistry, University of California, San Francisco, 1700 4th St., Byers Hall Suite 508D, San Francisco, CA 94143, USA
| | - Henry O'Donnell
- Department of Pharmaceutical Chemistry, University of California, San Francisco, 1700 4th St., Byers Hall Suite 508D, San Francisco, CA 94143, USA
| | - Walter Sandtner
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - John J Irwin
- Department of Pharmaceutical Chemistry, University of California, San Francisco, 1700 4th St., Byers Hall Suite 508D, San Francisco, CA 94143, USA
| | - Bryan L Roth
- Department of Pharmacology, NIMH Psychoactive Drug Screening Program, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Allan I Basbaum
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA.
| | - William C Wetsel
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA; Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical Center, Durham, NC 27710, USA; Departments of Cell Biology and Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
| | - Aashish Manglik
- Department of Pharmaceutical Chemistry, University of California, San Francisco, 1700 4th St., Byers Hall Suite 508D, San Francisco, CA 94143, USA; Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA 94115, USA.
| | - Brian K Shoichet
- Department of Pharmaceutical Chemistry, University of California, San Francisco, 1700 4th St., Byers Hall Suite 508D, San Francisco, CA 94143, USA.
| | - Gary Rudnick
- Department of Pharmacology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8066, USA.
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44
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Boytsov D, Schicker K, Hellsberg E, Freissmuth M, Sandtner W. Allosteric modulators of solute carrier function: a theoretical framework. Front Physiol 2023; 14:1166450. [PMID: 37250134 PMCID: PMC10210158 DOI: 10.3389/fphys.2023.1166450] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/24/2023] [Indexed: 05/31/2023] Open
Abstract
Large-scale drug screening is currently the basis for the identification of new chemical entities. This is a rather laborious approach, because a large number of compounds must be tested to cover the chemical space in an unbiased fashion. However, the structures of targetable proteins have become increasingly available. Thus, a new era has arguably been ushered in with the advent of methods, which allow for structure-based docking campaigns (i.e., virtual screens). Solute carriers (SLCs) are among the most promising drug targets. This claim is substantiated by the fact that a large fraction of the 400 solute carrier genes is associated with human diseases. The ability to dock large ligand libraries into selected structures of solute carriers has set the stage for rational drug design. In the present study, we show that these structure-based approaches can be refined by taking into account how solute carriers operate. We specifically address the feasibility of targeting solute carriers with allosteric modulators, because their actions differ fundamentally from those of ligands, which bind to the substrate binding site. For the pertinent analysis we used transition state theory in conjunction with the linear free energy relationship (LFER). These provide the theoretical framework to understand how allosteric modulators affect solute carrier function.
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Affiliation(s)
- D. Boytsov
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - K. Schicker
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - E. Hellsberg
- Computational Structural Biology Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, United States
| | - M. Freissmuth
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - W. Sandtner
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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45
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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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46
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Wang XN, Zhang JC, Zhang HY, Wang XF, You CX. Ectopic expression of MmSERT, a mouse serotonin transporter gene, regulates salt tolerance and ABA sensitivity in apple and Arabidopsis. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 197:107627. [PMID: 36940523 DOI: 10.1016/j.plaphy.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/20/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
5-hydroxytryptamine (5-HT) is ubiquitously present in animals and plants, playing a vital regulatory role. SERT, a conserved serotonin reuptake transporter in animals, regulates intracellular and extracellular concentrations of 5-HT. Few studies have reported 5-HT transporters in plants. Hence, we cloned MmSERT, a serotonin reuptake transporter, from Mus musculus. Ectopic expression of MmSERT into apple calli, apple roots and Arabidopsis. Because 5-HT plays a momentous role in plant stress tolerance, we used MmSERT transgenic materials for stress treatment. We found that MmSERT transgenic materials, including apple calli, apple roots and Arabidopsis, exhibited a stronger salt tolerance phenotype. The reactive oxygen species (ROS) produced were significantly lower in MmSERT transgenic materials compared with controls under salt stress. Meanwhile, MmSERT induced the expression of SOS1, SOS3, NHX1, LEA5 and LTP1 in response to salt stress. 5-HT is the precursor of melatonin, which regulates plant growth under adversity and effectively scavenges ROS. Detection of MmSERT transgenic apple calli and Arabidopsis revealed higher melatonin levels than controls. Besides, MmSERT decreased the sensitivity of apple calli and Arabidopsis to abscisic acid (ABA). In summary, these results demonstrated that MmSERT plays a vital role in plant stress resistances, which perhaps serves as a reference for the application of transgenic technology to improve crops in the future.
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Affiliation(s)
- Xiao-Na Wang
- National Key Laboratory of Crop Biology, MOA Key Laboratory of Horticultural Crop Biology and Germplasm Innovation, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, 271018, Shandong, China
| | - Jiu-Cheng Zhang
- National Key Laboratory of Crop Biology, MOA Key Laboratory of Horticultural Crop Biology and Germplasm Innovation, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, 271018, Shandong, China
| | - Hai-Yuan Zhang
- National Key Laboratory of Crop Biology, MOA Key Laboratory of Horticultural Crop Biology and Germplasm Innovation, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, 271018, Shandong, China
| | - Xiao-Fei Wang
- National Key Laboratory of Crop Biology, MOA Key Laboratory of Horticultural Crop Biology and Germplasm Innovation, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, 271018, Shandong, China.
| | - Chun-Xiang You
- National Key Laboratory of Crop Biology, MOA Key Laboratory of Horticultural Crop Biology and Germplasm Innovation, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, 271018, Shandong, China.
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47
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Zhu C, Liang X, Chen X, Liang M, Zheng J, Wan B, Luo S. Characterizing the Specific Recognition of Xanthurenic Acid by GEP1 and GEP1-GCα Interactions in cGMP Signaling Pathway in Gametogenesis of Malaria Parasites. Int J Mol Sci 2023; 24:ijms24032561. [PMID: 36768882 PMCID: PMC9916804 DOI: 10.3390/ijms24032561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 01/20/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023] Open
Abstract
Gametogenesis is an essential step for malaria parasite transmission and is activated in mosquito by signals including temperature drop, pH change, and mosquito-derived xanthurenic acid (XA). Recently, a membrane protein gametogenesis essential protein 1 (GEP1) was found to be responsible for sensing these signals and interacting with a giant guanylate cyclase α (GCα) to activate the cGMP-PKG-Ca2+ signaling pathway for malaria parasite gametogenesis. However, the molecular mechanisms for this process remain unclear. In this study, we used AlphaFold2 to predict the structure of GEP1 and found that it consists of a conserved N-terminal helical domain and a transmembrane domain that adopts a structure similar to that of cationic amino acid transporters. Molecular docking results showed that XA binds to GEP1 via a pocket similar to the ligand binding sites of known amino acid transporters. In addition, truncations of this N-terminal sequence significantly enhanced the expression, solubility, and stability of GEP1. In addition, we found that GEP1 interacts with GCα via its C-terminal region, which is interrupted by mutations of a few conserved residues. These findings provide further insights into the molecular mechanism for the XA recognition by GEP1 and the activation of the gametogenesis of malaria parasites through GEP1-GCα interaction.
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Affiliation(s)
- Cheng Zhu
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China
| | - Xiaoge Liang
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China
| | - Xu Chen
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China
| | - Miaomiao Liang
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China
| | - Jianting Zheng
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China
| | - Bingbing Wan
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China
- Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China
| | - Shukun Luo
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China
- Correspondence:
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48
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Galles GD, Infield DT, Clark CJ, Hemshorn ML, Manikandan S, Fazan F, Rasouli A, Tajkhorshid E, Galpin JD, Cooley RB, Mehl RA, Ahern CA. Tuning phenylalanine fluorination to assess aromatic contributions to protein function and stability in cells. Nat Commun 2023; 14:59. [PMID: 36599844 PMCID: PMC9813137 DOI: 10.1038/s41467-022-35761-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 12/27/2022] [Indexed: 01/05/2023] Open
Abstract
The aromatic side-chains of phenylalanine, tyrosine, and tryptophan interact with their environments via both hydrophobic and electrostatic interactions. Determining the extent to which these contribute to protein function and stability is not possible with conventional mutagenesis. Serial fluorination of a given aromatic is a validated method in vitro and in silico to specifically alter electrostatic characteristics, but this approach is restricted to a select few experimental systems. Here, we report a group of pyrrolysine-based aminoacyl-tRNA synthetase/tRNA pairs (tRNA/RS pairs) that enable the site-specific encoding of a varied spectrum of fluorinated phenylalanine amino acids in E. coli and mammalian (HEK 293T) cells. By allowing the cross-kingdom expression of proteins bearing these unnatural amino acids at biochemical scale, these tools may potentially enable the study of biological mechanisms which utilize aromatic interactions in structural and cellular contexts.
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Affiliation(s)
- Grace D Galles
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, USA
- The GCE4All Research Center, Department of Biochemistry & Biophysics, Oregon State University, Corvallis, OR, USA
| | - Daniel T Infield
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, USA
| | - Colin J Clark
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, USA
| | - Marcus L Hemshorn
- The GCE4All Research Center, Department of Biochemistry & Biophysics, Oregon State University, Corvallis, OR, USA
| | - Shivani Manikandan
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, USA
| | - Frederico Fazan
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, USA
| | - Ali Rasouli
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jason D Galpin
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, USA
| | - Richard B Cooley
- The GCE4All Research Center, Department of Biochemistry & Biophysics, Oregon State University, Corvallis, OR, USA
| | - Ryan A Mehl
- The GCE4All Research Center, Department of Biochemistry & Biophysics, Oregon State University, Corvallis, OR, USA
| | - Christopher A Ahern
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, USA.
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49
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Kanner BI, Dayan-Alon O. GABA transport goes structural. Trends Pharmacol Sci 2023; 44:4-6. [PMID: 35985875 DOI: 10.1016/j.tips.2022.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/29/2022] [Accepted: 08/03/2022] [Indexed: 12/27/2022]
Abstract
The γ-aminobutyric acid transporter 1 (GAT1) is a transporter which clears the inhibitory neurotransmitter γ-aminobutyric acid (GABA) from the synaptic cleft. The paper by Motiwala et al. documents a structure of GAT1 in complex with the antiepileptic drug tiagabine. This study will enable structure-based docking of large chemical libraries for the discovery of novel antiepileptics.
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Affiliation(s)
- Baruch I Kanner
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University, Hadassah Medical School, Jerusalem 91120, Israel.
| | - Oshrat Dayan-Alon
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University, Hadassah Medical School, Jerusalem 91120, Israel
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50
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Chavan SG, Yagati AK, Koyappayil A, Go A, Yeon S, Lee T, Lee MH. Conformationally Flexible Dimeric-Serotonin-Based Sensitive and Selective Electrochemical Biosensing Strategy for Serotonin Recognition. Anal Chem 2022; 94:17020-17030. [PMID: 36414244 DOI: 10.1021/acs.analchem.2c02747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A novel electrochemical sensor was constructed based on an enzyme-mediated physiological reaction between neurotransmitter serotonin per-oxidation to reconstruct dual-molecule 4,4'-dimeric-serotonin self-assembled derivative, and the potential biomedical application of the multi-functional nano-platform was explored. Serotonin accelerated the catalytic activity to form a dual molecule at the C4 position and created phenolic radical-radical coupling intermediates in a peroxidase reaction system. Here, 4,4' dimeric-serotonin possessed the capability to recognize intermolecular interactions between amine groups. The excellent quenching effects on top of the gold surface electrode system archive logically inexpensive and straightforward analytical demands. In biochemical sensing analysis, the serotonin dimerization concept demonstrated a robust, low-cost, and highly sensitive immunosensor, presenting the potential of quantifying serotonin at point-of-care (POC) testing. The high-specificity serotonin electrochemical sensor had a limit of detection (LOD) of 0.9 nM in phosphate buffer and 1.4 nM in human serum samples and a linear range of 10 to 400 with a sensitivity of 2.0 × 10-2 nM. The bivalent 4,4'-dimer-serotonin interaction strategy provides a promising platform for serotonin biosensing with high specificity, sensitivity, selectivity, stability, and reproducibility. The self-assembling gold surface electrochemical system presents a new analytical method for explicitly detecting tiny neurotransmitter-responsive serotonin neuromolecules.
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Affiliation(s)
- Sachin Ganpat Chavan
- School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-Gu, Seoul06974, South Korea
| | - Ajay Kumar Yagati
- School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-Gu, Seoul06974, South Korea
| | - Aneesh Koyappayil
- School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-Gu, Seoul06974, South Korea
| | - Anna Go
- School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-Gu, Seoul06974, South Korea
| | - Sangho Yeon
- School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-Gu, Seoul06974, South Korea
| | - Taek Lee
- Department of Chemical Engineering, Kwangwoon University, 20 Kwangwoon-Ro, Nowon-Gu, Seoul01897, Republic of Korea
| | - Min-Ho Lee
- School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-Gu, Seoul06974, South Korea
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