51
|
Gong W, Liu Y, Zhao Y, Wang S, Han Z, Li C. Equally Weighted Multiscale Elastic Network Model and Its Comparison with Traditional and Parameter-Free Models. J Chem Inf Model 2021; 61:921-937. [PMID: 33496590 DOI: 10.1021/acs.jcim.0c01178] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dynamical properties of proteins play an essential role in their function exertion. The elastic network model (ENM) is an effective and efficient tool in characterizing the intrinsic dynamical properties encoded in biomacromolecule structures. The Gaussian network model (GNM) and anisotropic network model (ANM) are the two often-used ENM models. Here, we introduce an equally weighted multiscale ENM (equally weighted mENM) based on the original mENM (denoted as mENM), in which fitting weights of Kirchhoff/Hessian matrixes in mENM are removed since they neglect the details of pairwise interactions. Then, we perform its comparison with the mENM, traditional ENM, and parameter-free ENM (pfENM) in reproducing dynamical properties for the six representative proteins whose molecular dynamics (MD) trajectories are available in http://mmb.pcb.ub.es/MoDEL/. In the results, for B-factor prediction, mENM performs best, while the equally weighted mENM performs also well, better than the traditional ENM and pfENM models. As to the dynamical cross-correlation map calculation, mENM performs worst, while the results produced from the equally weighted mENM and pfENM models are close to those from MD trajectories with the latter a little better than the former. Furthermore, encouragingly, the equally weighted mANM displays the best performance in capturing the functional motional modes, followed by pfANM and traditional ANM models, while the mANM fails in all the cases. This work is helpful for strengthening the understanding of the elastic network model and provides a valuable guide for researchers to utilize the model to explore protein dynamics.
Collapse
Affiliation(s)
- Weikang Gong
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Yang Liu
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Yanpeng Zhao
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Shihao Wang
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Zhongjie Han
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Chunhua Li
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| |
Collapse
|
52
|
Li ZH, Ma PK, Huang YF, Zhang Z, Zheng W, Chen JH, Guo CE, Chen N, Bi XN, Zhang YJ. Jiaotai Pill () Alleviates Insomnia through Regulating Monoamine and Organic Cation Transporters in Rats. Chin J Integr Med 2021; 27:183-191. [PMID: 33420587 DOI: 10.1007/s11655-021-3284-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To reveal the effect and mechanism of Jiaotai Pill (, JTP) on insomniac rats. METHODS The insomniac model was established by intraperitoneal injection of p-chlorophenylalanine (PCPA). In behavioral experiments, rats were divided into control, insomniac model, JTP [3.3 g/(kg•d)], and diazepam [4 mg/(kg•d)] groups. The treatment effect of JTP was evaluated by weight measurement (increasement of body weight), open field test (number of crossings) and forced swimming test (immobility time). A high performance liquid chromatography-electrochemical detection (HPLC-ECD) method was built to determine the concentration of monoamine transmitters in hypothalamus and peripheral organs from normal, model, JTP, citalopram [30 mg/(kg•d)], maprotiline [40 mg/(kg•d)] and bupropion [40 mg/(kg•d)] groups. Expressions of serotonin transporter (SERT), dopamine transporter (DAT), and norepinephrine transporter (NET) were analyzed by quantitative polymerase chain reaction (qPCR) and Western blot in normal, model and JTP groups. A high performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS/MS) method was established to determine the pharmacokinetics, urine cumulative excretion of metformin in vivo, and tissue slice uptake in vitro, which were applied to assess the activity of organic cation transporters (OCTs) in hypothalamus and peripheral organs. RESULTS Compared with the insomniac model group, the body weight and spontaneous locomotor were increased, and the immobility time was decreased after treatment with JTP (P<0.01). Both serotonin and dopamine contents in hypothalamus and peripheral organs were increased (P<0.01). The norepinephrine content was increased in peripheral organs and decreased in hypothalamus (P<0.05 or P<0.01). At the same time, SERT, DAT, OCT1, OCT2, and OCT3 were down-regulated in hypothalamus and peripheral organs (P<0.05). NET was down-regulated in peripheral organs and up-regulated in hypothalamus (P<0.05 or P<0.01). Moreover, the activity of OCTs in hypothalamus and peripheral organs was inhibited (P<0.05). CONCLUSION JTP alleviates insomnia through regulation of monoaminergic system and OCTs in hypothalamus and peripheral organs.
Collapse
Affiliation(s)
- Zhi-Hui Li
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Peng-Kai Ma
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | | | - Zhe Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Wei Zheng
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Jian-Hua Chen
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Chang-E Guo
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Ning Chen
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Xin-Ning Bi
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Yu-Jie Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China.
| |
Collapse
|
53
|
Romanazzi T, Zanella D, Cheng MH, Smith B, Carter AM, Galli A, Bahar I, Bossi E. Bile Acids Gate Dopamine Transporter Mediated Currents. Front Chem 2021; 9:753990. [PMID: 34957043 PMCID: PMC8702627 DOI: 10.3389/fchem.2021.753990] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 11/16/2021] [Indexed: 11/21/2022] Open
Abstract
Bile acids (BAs) are molecules derived from cholesterol that are involved in dietary fat absorption. New evidence supports an additional role for BAs as regulators of brain function. Sterols such as cholesterol interact with monoamine transporters, including the dopamine (DA) transporter (DAT) which plays a key role in DA neurotransmission and reward. This study explores the interactions of the BA, obeticholic acid (OCA), with DAT and characterizes the regulation of DAT activity via both electrophysiology and molecular modeling. We expressed murine DAT (mDAT) in Xenopus laevis oocytes and confirmed its functionality. Next, we showed that OCA promotes a DAT-mediated inward current that is Na+-dependent and not regulated by intracellular calcium. The current induced by OCA was transient in nature, returning to baseline in the continued presence of the BA. OCA also transiently blocked the DAT-mediated Li+-leak current, a feature that parallels DA action and indicates direct binding to the transporter in the absence of Na+. Interestingly, OCA did not alter DA affinity nor the ability of DA to promote a DAT-mediated inward current, suggesting that the interaction of OCA with the transporter is non-competitive, regarding DA. Docking simulations performed for investigating the molecular mechanism of OCA action on DAT activity revealed two potential binding sites. First, in the absence of DA, OCA binds DAT through interactions with D421, a residue normally involved in coordinating the binding of the Na+ ion to the Na2 binding site (Borre et al., J. Biol. Chem., 2014, 289, 25764-25773; Cheng and Bahar, Structure, 2015, 23, 2171-2181). Furthermore, we uncover a separate binding site for OCA on DAT, of equal potential functional impact, that is coordinated by the DAT residues R445 and D436. Binding to that site may stabilize the inward-facing (IF) open state by preventing the re-formation of the IF-gating salt bridges, R60-D436 and R445-E428, that are required for DA transport. This study suggests that BAs may represent novel pharmacological tools to regulate DAT function, and possibly, associated behaviors.
Collapse
Affiliation(s)
- Tiziana Romanazzi
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Daniele Zanella
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mary Hongying Cheng
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Behrgen Smith
- Department of Physics and Chemistry, Biomolecular Engineering, Milwaukee School of Engineering, Milwaukee, WI, United States
| | - Angela M Carter
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Aurelio Galli
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Ivet Bahar
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Elena Bossi
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy.,Center for Research in Neuroscience, University of Insubria, Varese, Italy
| |
Collapse
|
54
|
Ryuzaki S, Matsuda R, Taniguchi M. Pore Structures for High-Throughput Nanopore Devices. MICROMACHINES 2020; 11:mi11100893. [PMID: 32993177 PMCID: PMC7600762 DOI: 10.3390/mi11100893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 09/25/2020] [Accepted: 09/25/2020] [Indexed: 11/16/2022]
Abstract
Nanopore devices are expected to advance the next-generation of nanobiodevices because of their strong sensing and analyzing capabilities for single molecules and bioparticles. However, the device throughputs are not sufficiently high. Although analytes pass through a nanopore by electrophoresis, the electric field gradient is localized inside and around a nanopore structure. Thus, analytes located far from a nanopore cannot be driven by electrophoresis. Here, we report nanopore structures for high-throughput sensing, namely, inverted pyramid (IP)-shaped nanopore structures. Silicon-based IP-shaped nanopore structures create a homogeneous electric field gradient within a nanopore device, indicating that most of the analytes can pass through a nanopore by electrophoresis, even though the analytes are suspended far from the nanopore entrance. In addition, the nanostructures can be fabricated only by photolithography. The present study suggests a high potential for inverted pyramid shapes to serve as nanopore devices for high-throughput sensing.
Collapse
Affiliation(s)
- Sou Ryuzaki
- Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka 819-0395, Japan;
- PRESTO, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
- Correspondence: (S.R.); (M.T.); Tel.: +81-092-642-2726 (S.R.); +81-6-6875-2440 (M.T.)
| | - Rintaro Matsuda
- Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka 819-0395, Japan;
| | - Masateru Taniguchi
- The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan
- Correspondence: (S.R.); (M.T.); Tel.: +81-092-642-2726 (S.R.); +81-6-6875-2440 (M.T.)
| |
Collapse
|
55
|
Xu L, Chen LY. Identification of a New Allosteric Binding Site for Cocaine in Dopamine Transporter. J Chem Inf Model 2020; 60:3958-3968. [PMID: 32649824 PMCID: PMC7484383 DOI: 10.1021/acs.jcim.0c00346] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dopamine (DA) transporter (DAT) is a major target for psychostimulant drugs of abuse such as cocaine that competitively binds to DAT, inhibits DA reuptake, and consequently increases synaptic DA levels. In addition to the central binding site inside DAT, the available experimental evidence suggests the existence of alternative binding sites on DAT, but detection and characterization of these sites are challenging by experiments alone. Here, we integrate multiple computational approaches to probe the potential binding sites on the wild-type Drosophila melanogaster DAT and identify a new allosteric site that displays high affinity for cocaine. This site is located on the surface of DAT, and binding of cocaine is primarily dominated by interactions with hydrophobic residues surrounding the site. We show that cocaine binding to this new site allosterically reduces the binding of DA/cocaine to the central binding pocket, and simultaneous binding of two cocaine molecules to a single DAT seems infeasible. Furthermore, we find that binding of cocaine to this site stabilizes the conformation of DAT but alters the conformational population and thereby reduces the accessibility by DA, providing molecular insights into the inhibitory mechanism of cocaine. In addition, our results indicate that the conformations induced by cocaine binding to this site may be relevant to the oligomerization of DAT, highlighting a potential role of this new site in modulating the function of DAT.
Collapse
Affiliation(s)
- Liang Xu
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, United States
| | - Liao Y Chen
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, United States
| |
Collapse
|
56
|
Colas C. Toward a Systematic Structural and Functional Annotation of Solute Carriers Transporters-Example of the SLC6 and SLC7 Families. Front Pharmacol 2020; 11:1229. [PMID: 32973497 PMCID: PMC7466448 DOI: 10.3389/fphar.2020.01229] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/28/2020] [Indexed: 12/12/2022] Open
Abstract
SLC transporters are emerging key drug targets. One important step for drug development is the profound understanding of the structural determinants defining the substrate selectivity of each transporter. Recently, the improvement of computational power and experimental methods such as X-ray and cryo-EM crystallography permitted to conduct structure-based studies on specific transporters having important pharmacological impact. However, a lot remains to be discovered regarding their dynamics, transport modulation and ligand recognition. A detailed functional characterization of transporters would provide opportunities to develop new compounds targeting these key drug targets. Here, we are giving an overview of two major human LeuT-fold families, SLC6 and SLC7, with an emphasis on the most relevant members of each family for drug development. We gather the most recent understanding on the structural determinants of selectivity within and across the two families. We then use this information to discuss the benefits of a more generalized structural and functional annotation of the LeuT fold and the implications of such mapping for drug discovery.
Collapse
Affiliation(s)
- Claire Colas
- University of Vienna, Department of Pharmaceutical Chemistry, Vienna, Austria
| |
Collapse
|
57
|
Loi B, Sahai MA, De Luca MA, Shiref H, Opacka-Juffry J. The Role of Dopamine in the Stimulant Characteristics of Novel Psychoactive Substances (NPS)-Neurobiological and Computational Assessment Using the Case of Desoxypipradrol (2-DPMP). Front Pharmacol 2020; 11:806. [PMID: 32670057 PMCID: PMC7289955 DOI: 10.3389/fphar.2020.00806] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 05/18/2020] [Indexed: 11/13/2022] Open
Abstract
Stimulant drugs, including novel psychoactive substances (NPS, formerly “legal highs”) have addictive potential which their users may not realize. Stimulants increase extracellular dopamine levels in the brain, including the reward and addiction pathways, through interacting with dopamine transporter (DAT). This work aimed to assess the molecular and atomistic mechanisms of stimulant NPS actions at DAT, which translate into biological outcomes such as dopamine release in the brain’s reward pathway. We applied combined in vitro, in vivo, and in silico methods and selected 2-diphenylmethylpiperidine (2-DPMP) as an example of stimulant NPS for this study. We measured in vitro binding of 2-DPMP to rat striatum and accumbens DAT by means of quantitative autoradiography with a selective DAT-radioligand [125I]RTI-121. We evaluated the effects of intravenously administered 2-DPMP on extracellular dopamine in the accumbens-shell and striatum using in vivo microdialysis in freely moving rats. We used dynamic modeling to investigate the interactions of 2-DPMP within DAT, in comparison with cocaine and amphetamine. 2-DPMP potently displaced the radioligand in the accumbens and striatum showing dose-dependence from 0.3 to 30 μM. IC50 values were: 5.65 × 10-7M for accumbens shell and 6.21 × 10-7M for dorsal striatum. Dose-dependent responses were also observed in accumbens-shell and striatum in vivo, with significant increases in extracellular dopamine levels. Molecular dynamics simulations identified contrasting conformational changes of DAT for inhibitors (cocaine) and releasers (amphetamine). 2-DPMP led to molecular rearrangements toward an outward-facing DAT conformation that suggested a cocaine-type effect. The present combination of molecular modeling with experimental neurobiological procedures allows for extensive characterization of the mechanisms of drug actions at DAT as the main molecular target of stimulants, and provides an insight into the role of dopamine in the molecular and neurobiological mechanisms of brain responses to stimulant NPS that have addictive potential. Such knowledge reveals the risk of addiction related to NPS use. The research presented here can be adapted for other psychostimulants that act at their membrane protein targets.
Collapse
Affiliation(s)
- Barbara Loi
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, Department of Pharmacy, Postgraduate Medicine and Pharmacology, University of Hertfordshire, Hatfield, United Kingdom.,Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Michelle A Sahai
- Department of Life Sciences, University of Roehampton, London, United Kingdom
| | | | - Hana Shiref
- Department of Life Sciences, University of Roehampton, London, United Kingdom
| | | |
Collapse
|
58
|
Zhu R, Sandtner W, Ahiable JEA, Newman AH, Freissmuth M, Sitte HH, Hinterdorfer P. Allosterically Linked Binding Sites in Serotonin Transporter Revealed by Single Molecule Force Spectroscopy. Front Mol Biosci 2020; 7:99. [PMID: 32656227 PMCID: PMC7325972 DOI: 10.3389/fmolb.2020.00099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 05/01/2020] [Indexed: 01/24/2023] Open
Abstract
Crystal structures and experiments relying on the tools of molecular pharmacology reported conflicting results on ligand binding sites in neurotransmitter/sodium symporters (NSS). We explored the number and functionality of ligand binding sites of NSS in a physiological setting by designing novel tools for atomic force microscopy (AFM). These allow for directly measuring the interaction forces between the serotonin transporter (SERT) and the antidepressant S-citalopram (S-CIT) on the single molecule level: the AFM cantilever tips were functionalized with S-CIT via a flexible polyethylene glycol (PEG) linker. The tip chemistry was validated by specific force measurements and recognition imaging on CHO cells. Two distinct populations of characteristic binding strengths of S-CIT binding to SERT were revealed in Na+-containing buffer. In contrast, in Li+-containing buffer, SERT showed only low force interactions. Conversely, the vestibular mutant SERT-G402H merely displayed the high force population. These observations provide physical evidence for the existence of two binding sites in SERT. The dissociation rate constant of both binding sites was extracted by varying the dynamics of the force-probing experiments. Competition experiments revealed that the two sites are allosterically coupled and exert reciprocal modulation.
Collapse
Affiliation(s)
- Rong Zhu
- Institute of Biophysics, Johannes Kepler University Linz, Linz, Austria
| | - Walter Sandtner
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Joan E A Ahiable
- Institute of Biophysics, Johannes Kepler University Linz, Linz, Austria
| | - Amy Hauck Newman
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, MD, United States
| | - Michael Freissmuth
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Harald H Sitte
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | | |
Collapse
|
59
|
X-ray structure of LeuT in an inward-facing occluded conformation reveals mechanism of substrate release. Nat Commun 2020; 11:1005. [PMID: 32081981 PMCID: PMC7035281 DOI: 10.1038/s41467-020-14735-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 01/24/2020] [Indexed: 12/21/2022] Open
Abstract
Neurotransmitter:sodium symporters (NSS) are conserved from bacteria to man and serve as targets for drugs, including antidepressants and psychostimulants. Here we report the X-ray structure of the prokaryotic NSS member, LeuT, in a Na+/substrate-bound, inward-facing occluded conformation. To obtain this structure, we were guided by findings from single-molecule fluorescence spectroscopy and molecular dynamics simulations indicating that L-Phe binding and mutation of the conserved N-terminal Trp8 to Ala both promote an inward-facing state. Compared to the outward-facing occluded conformation, our structure reveals a major tilting of the cytoplasmic end of transmembrane segment (TM) 5, which, together with release of the N-terminus but without coupled movement of TM1, opens a wide cavity towards the second Na+ binding site. The structure of this key intermediate in the LeuT transport cycle, in the context of other NSS structures, leads to the proposal of an intracellular release mechanism of substrate and ions in NSS proteins.
Collapse
|
60
|
Abstract
The transport of materials across membranes is a vital process for all aspects of cellular function, including growth, metabolism, and communication. Protein transporters are the molecular gates that control this movement and serve as key points of regulation for these processes, thus representing an attractive class of therapeutic targets. With more than 400 members, the solute carrier (SLC) membrane transport proteins are the largest family of transporters, yet, they are pharmacologically underexploited relative to other protein families and many of the available chemical tools possess suboptimal selectivity and efficacy. Fortuitously, there is increased interest in elucidating the physiological roles of SLCs as well as growing recognition of their therapeutic potential. This Perspective provides an overview of the SLC superfamily, including their biochemical and functional features, as well as their roles in various human diseases. In particular, we explore efforts and associated challenges toward drugging SLCs, as well as highlight opportunities for future drug discovery.
Collapse
Affiliation(s)
- Wesley Wei Wang
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Leandro Gallo
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Appaso Jadhav
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Richard Hawkins
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Christopher G Parker
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States.,Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| |
Collapse
|
61
|
Zhang X, Chen W, Li P, Calvo R, Southall N, Hu X, Bryant-Genevier M, Feng X, Geng Q, Gao C, Yang M, Tang K, Ferrer M, Marugan JJ, Xu H. Agonist-specific voltage-dependent gating of lysosomal two-pore Na + channels. eLife 2019; 8:e51423. [PMID: 31825310 PMCID: PMC6905855 DOI: 10.7554/elife.51423] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/23/2019] [Indexed: 12/12/2022] Open
Abstract
Mammalian two-pore-channels (TPC1, 2; TPCN1, TPCN2) are ubiquitously- expressed, PI(3,5)P2-activated, Na+-selective channels in the endosomes and lysosomes that regulate luminal pH homeostasis, membrane trafficking, and Ebola viral infection. Whereas the channel activity of TPC1 is strongly dependent on membrane voltage, TPC2 lacks such voltage dependence despite the presence of the presumed 'S4 voltage-sensing' domains. By performing high-throughput screening followed by lysosomal electrophysiology, here we identified a class of tricyclic anti-depressants (TCAs) as small-molecule agonists of TPC channels. TCAs activate both TPC1 and TPC2 in a voltage-dependent manner, referred to as Lysosomal Na+ channel Voltage-dependent Activators (LyNa-VAs). We also identified another compound which, like PI(3,5)P2, activates TPC2 independent of voltage, suggesting the existence of agonist-specific gating mechanisms. Our identification of small-molecule TPC agonists should facilitate the studies of the cell biological roles of TPCs and can also readily explain the reported effects of TCAs in the modulation of autophagy and lysosomal functions.
Collapse
Affiliation(s)
- Xiaoli Zhang
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
| | - Wei Chen
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
| | - Ping Li
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
- Collaborative Innovation Center of Yangtze River Delta Region Green PharmaceuticalsZhejiang University of TechnologyHangzhouChina
| | - Raul Calvo
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Noel Southall
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Xin Hu
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Melanie Bryant-Genevier
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Xinghua Feng
- Collaborative Innovation Center of Yangtze River Delta Region Green PharmaceuticalsZhejiang University of TechnologyHangzhouChina
| | - Qi Geng
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
| | - Chenlang Gao
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
| | - Meimei Yang
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
- Department of NeurologyThe Fourth Hospital of Harbin Medical UniversityHarbinChina
| | - Kaiyuan Tang
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
| | - Marc Ferrer
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Juan Jose Marugan
- National Center for Advancing Translational Sciences (NCATS)Medical Center DriveRockvilleUnited States
| | - Haoxing Xu
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborUnited States
| |
Collapse
|
62
|
Joseph D, Pidathala S, Mallela AK, Penmatsa A. Structure and Gating Dynamics of Na +/Cl - Coupled Neurotransmitter Transporters. Front Mol Biosci 2019; 6:80. [PMID: 31555663 PMCID: PMC6742698 DOI: 10.3389/fmolb.2019.00080] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 08/21/2019] [Indexed: 12/24/2022] Open
Abstract
Neurotransmitters released at the neural synapse through vesicle exocytosis are spatiotemporally controlled by the action of neurotransmitter transporters. Integral membrane proteins of the solute carrier 6 (SLC6) family are involved in the sodium and chloride coupled uptake of biogenic amine neurotransmitters including dopamine, serotonin, noradrenaline and inhibitory neurotransmitters including glycine and γ-amino butyric acid. This ion-coupled symport works through a well-orchestrated gating of substrate through alternating-access, which is mediated through movements of helices that resemble a rocking-bundle. A large array of commercially prescribed drugs and psychostimulants selectively target neurotransmitter transporters thereby modulating their levels in the synaptic space. Drug-induced changes in the synaptic neurotransmitter levels can be used to treat depression or neuropathic pain whereas in some instances prolonged usage can lead to habituation. Earlier structural studies of bacterial neurotransmitter transporter homolog LeuT and recent structure elucidation of the Drosophila dopamine transporter (dDAT) and human serotonin transporter (hSERT) have yielded a wealth of information in understanding the transport and inhibition mechanism of neurotransmitter transporters. Computational studies based on the structures of dDAT and hSERT have shed light on the dynamics of varied components of these molecular gates in affecting the uphill transport of neurotransmitters. This review seeks to address structural dynamics of neurotransmitter transporters at the extracellular and intracellular gates and the effect of inhibitors on the ligand-binding pocket. We also delve into the effect of additional factors including lipids and cytosolic domains that influence the translocation of neurotransmitters across the membrane.
Collapse
Affiliation(s)
- Deepthi Joseph
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | | | | | - Aravind Penmatsa
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| |
Collapse
|
63
|
Neuronal communication. Nat Struct Mol Biol 2019; 26:527. [PMID: 31270473 DOI: 10.1038/s41594-019-0265-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|