Neurotransmitter Transporters

by Sitte, Harald H.; Freissmuth, Michael

• ISBN13: 9783540297833
• ISBN10: 3540297839
• Edition: 1st
• Format: Hardcover
• Copyright: 2006-06-15
• Publisher: Springer Verlag

Summary

The present volume of the Handbook of Experimental Pharmacology gives a representative survey of the current status of the structure, function, regulation and molecular pharmacology of Neurotransmitter Transporters and aims at providing an overview of insights that were generated in the past 5 years. If the volume serves as both, a useful compendium of current concepts and an inspiring starting point, it will have fulfilled its mission and will be a source for students interested in this emerging field as well as for experienced scientists looking for an update. This volume is the brainchild of the editor-in-chief of the HEP series, Klaus Starke, awe-inspiring to all pharmacologists of younger generations.

Table of Contents

Zn²+ Modulation of Neurotransmitter Transporters	1	(22)
K. Nørgaard-Nielsen, U. Gether
1 Introduction	2	(3)
2 Synaptic Zn²+ Is a Potential Modulator of Several Neurotransmitter Systems	5	(2)
3 Endogenous Zn²+-Binding Sites in Na+/Cl-Dependent Neurotransmitter Transporters	7	(2)
4 Endogenous Zn²+-Binding Sites in the Excitatory Amino Acid Transporters	9	(2)
5 Zn²+ Modulation of DAT Function	11	(2)
6 Reversal of Zn²+ Sensitivity by Intracellular Mutations in the DAT	13	(3)
7 Zn²+ Is Found in Presynaptic Vesicles and is Released Upon Neuronal Stimulation	16	(2)
References	18	(5)
Molecular Microfluorometry: Converting Arbitrary Fluorescence Units into Absolute Molecular Concentrations to Study Binding Kinetics and Stoichiometry in Transporters	23	(36)
J.W. Schwartz, D. Piston, L.J. DeFelice
1 Introduction	24	(27)
1.1 Neurotransmitter Transporters Conduct Transmitters Across Membranes	24	(3)
1.2 Methods to Study Transporter Function	27	(50)
1.2.1 Radiometric Assay	27	(2)
1.2.2 Electrophysiology	29	(2)
1.2.3 Amperometry and Cyclic Voltammetry	31	(1)
1.2.4 Quantitative Fluorescence Microscopy	32	(1)
1.2.5 Confocal Microscopy and Two-Photon Excitation	33	(7)
1.2.6 TIRF Microscopy	40	(2)
1.2.7 Fluorescence Lifetime Imaging Microscopy	42	(3)
1.2.8 Fluorescence Correlation Spectroscopy	45	(3)
1.2.9 Fluorescence Recovery After Photobleaching	48	(2)
1.2.10 Fluorescence Plate Reader	50	(1)
2 Summary	51	(1)
References	52	(7)
Structure/Function Relationships in Serotonin Transporter: New Insights from the Structure of a Bacterial Transporter	59	(16)
G. Rudnick
1 General Background and Significance of SERT	59	(2)
2 Mechanism of Transport	61	(2)
3 Topology	63	(2)
4 The Permeation Pathway	65	(1)
5 The Substrate Binding Site	66	(1)
6 Conformational Changes	67	(3)
7 Future Directions	70	(1)
References	71	(4)
The Importance of Company: Na+ and Cl- Influence Substrate Interaction with SLC6 Transporters and Other Proteins	75	(20)
M.E.A. Reith, J. Zhen, N. Chen
1 Introduction	76	(1)
2 Cotransport of Na+ and Cl- with Substrate in SLC6 Family	76	(1)
3 Residues Controlling Na+ Modulation	77	(9)
3.1 SLC6 Family	77	(4)
3.2 SLC1A2 in SLC1 Family	81	(2)
3.3 PutP and SGLT1 in SGLT Family	83	(1)
3.4 Other Transporters or Pumps	84	(2)
4 Cl- Binding to Proteins and Cl- Modulation of Transport Proteins	86	(2)
5 Comments on Transporter Residues Governing Na+ and Cl- Modulation of Transport	88	(1)
References	89	(6)
Currents in Neurotransmitter Transporters	95	(18)
K. Gerstbrein, H.H. Sitte
1 Introduction	95	(3)
2 Electrophysiological Background in a Nutshell	98	(1)
3 Coupled and Uncoupled Currents	99	(1)
4 The Single-File Model	100	(1)
5 Transient Currents	101	(1)
6 Leak Current	102	(1)
7 Is There a Physiological Role for Transporter-Associated Currents?	103	(2)
8 Currents and Amphetamines	105	(3)
References	108	(5)
Mutational Analysis of Glutamate Transporters	113	(24)
R.J. Vandenberg
1 Glutamate Transporters	114	(1)
2 Ion/Flux Coupling Determines the Concentrating Capacity of the Transporters	114	(2)
3 Uncoupled Ion Currents Associated with Glutamate Transporters	116	(1)
4 The Structure of a Bacterial Glutamate Transporter	117	(1)
5 Mutational Studies of Mammalian Glutamate Transporters	118	(12)
5.1 General Considerations and Approaches	118	(1)
5.2 Structural Studies Using Site-Directed Mutagenesis	119	(3)
5.2.1 Cysteine-Scanning Mutagenesis	119	(2)
5.2.2 Cross-Linking of Cysteine Mutants	121	(1)
5.3 Substrate Recognition and Translocation	122	(5)
5.3.1 The Use of Chimeras to Define Functional Domains	122	(1)
5.3.2 Glutamate and Ion Binding Sites	123	(3)
5.3.3 Glutamate Binding Site in the Crystal Structure of Gltph	126	(1)
5.4 Zn²+ Binding Sites on EAAT1 and EAAT4	127	(1)
5.5 The Chloride Channel Within the Transporter	127	(11)
5.5.1 Different Conformational States Regulate the Two Functions	128	(1)
5.5.2 Residues that Line the Chloride Channel	129	(1)
5.5.3 Opening the Chloride Channel Gate	130	(1)
6 A Structural Model for the Transport and Chloride Channel Functions of Glutamate Transporters	130	(2)
References	132	(5)
The Diverse Roles of Vesicular Glutamate Transporter 3	137	(14)
R.P. Seal, R.H. Edwards
1 Introduction	137	(1)
2 Vesicular Glutamate Transport	138	(4)
2.1 Identification of the Vesicular Glutamate Transporters	139	(1)
2.2 Catecholamine Neurons Express VGLUT2	140	(1)
2.3 Glutamate Release by Dopamine Neurons In Vivo	141	(1)
3 Identification of VGLUT3 in Neurons and Glia	142	(4)
3.1 VGLUT3 in Monoamine Neurons	143	(1)
3.2 Cholinergic Interneurons of the Striatum	144	(1)
3.3 Inhibitory Interneurons of the Hippocampus, Cortex, and Retina	144	(1)
3.4 Dendritic Release of Glutamate	145	(1)
3.5 Expression of VGLUT3 Transiently During Development	146	(1)
4 Conclusion	146	(1)
References	147	(4)
Extraneuronal Monoamine Transporter and Organic Cation Transporters 1 and 2: A Review of Transport Efficiency	151	(30)
E. Schömig, A. Lazar, D. Gründemann
1 Introduction	152	(3)
1.1 Structure and Function	152	(1)
1.2 Localization	153	(1)
1.3 Genes, Polymorphisms and Knock-Out Mice	153	(2)
2 Substrate Specificity	155	(17)
2.1 Analysis of Transport Efficiency	155	(2)
2.2 OCT1	157	(5)
2.3 OCT2	162	(7)
2.4 EMT	169	(3)
3 Roundup	172	(3)
References	175	(6)
The Role of SNARE Proteins in Trafficking and Function of Neurotransmitter Transporters	181	(16)
M.W. Quick
1 Introduction	182	(4)
1.1 SNARE Proteins	182	(2)
1.2 Syntaxin 1A Regulation of Ion Channels	184	(1)
1.3 Initial Evidence for SNARE Regulation of Neurotransmitter Transporters	185	(1)
2 Overview of Syntaxin IA Regulation of Neurotransmitter Transporters	186	(2)
2.1 Glycine Transporters	186	(1)
2.2 Amine Transporters	187	(1)
2.3 Glutamate Transporters	187	(1)
3 Details of Syntaxin lA Regulation of GAT1	188	(3)
3.1 Regulation of GAT1 Trafficking	188	(1)
3.2 Regulation of Intrinsic Properties of GAT1	189	(2)
4 Syntaxin IA Regulation of SERT Conducting States	191	(2)
5 Conclusions	193	(1)
References	193	(4)
Regulation of the Dopamine Transporter by Phosphorylation	197	(18)
J.D. Foster, M.A. Cervinski, B.K. Gorentla, R.A. Vaughan
1 Introduction to the Dopamine Transporter	198	(2)
1.1 The Na+/Cl-Dependent Neurotransmitter Transporter Family	198	(1)
1.2 Interactions with Psychostimulants, Therapeutic Drugs, and Neurotoxins	199	(1)
2 Dopamine Transporter Phosphorylation	200	(9)
2.1 Effects of Kinases and Phosphatases	201	(3)
2.2 Phosphorylation Sites	204	(1)
2.3 Transporter Downregulation	205	(1)
2.4 Effects of Substrates	206	(2)
2.5 Effects of Transport Blockers	208	(1)
3 Future Perspectives	209	(1)
References	210	(5)
The Dopamine Transporter: A Vigilant Border Control for Psychostimulant Action	215	(18)
J.M. Williams, A. Galli
1 Introduction: Dopamine Transmission and Psychostimulants	216	(2)
2 Ion Channel-Like Behavior of the DAT	218	(3)
3 Regulation of DAT Function by Its Substrates	221	(3)
4 Regulation of DAT Function by Its Inhibitors	224	(1)
5 Dopamine D2 Receptor Modulation of DAT Function	225	(1)
6 Summary	226	(1)
References	227	(6)
Oligomerization of Neurotransmitter Transporters: A Ticket from the Endoplasmic Reticulum to the Plasma Membrane	233	(18)
H. Farhan, M. Freissmuth, H.H. Sitte
1 Oligomerization of Neurotransmitter Transporters	234	(3)
1.1 The Structural Basis of Oligomer Formation	234	(3)
2 The ER Export	237	(3)
2.1 Selective Export Vs Selective Retention	238	(2)
3 Oligomerization and ER Export	240	(5)
3.1 Sensors of Oligomeric Assembly	242	(1)
3.2 Oligomerization and Exit from the Golgi	242	(1)
3.3 Life Visualization of Oligomer Formation in the Secretory Pathway	243	(1)
3.4 The Importance of Oligomer Formation for the Action of Amphetamine	243	(2)
References	245	(6)
Acute Regulation of Sodium-Dependent Glutamate Transporters: A Focus on Constitutive and Regulated Trafficking	251	(26)
M.B. Robinson
1 Introduction	252	(2)
2 Characteristics of Na+-Dependent Glutamate Transporters	254	(3)
2.1 Localization	254	(1)
2.2 Contributions to Synaptic Transmission	254	(2)
2.3 Role in Toxicity	256	(1)
3 Rapid Regulation of Glutamate Transporters	257	(13)
3.1 General Comments Regarding Plasma Membrane Expression of Glutamate Transporters	260	(2)
3.2 Constitutive Trafficking of Glutamate Transporters	262	(2)
3.3 EAAC1/EAAT3	264	(3)
3.4 GLT-1/EAAT2	267	(2)
3.5 GLAST/EAAT1	269	(1)
4 Conclusions	270	(1)
References	270	(7)
Regulation and Dysregulation of Glutamate Transporters	277	(28)
R. Sattler, J.D. Rothstein
1 Introduction	278	(3)
1.1 Glutamate	278	(2)
1.2 Glutamate Transporter	280	(1)
2 Regulation of Glutamate Transporters	281	(13)
2.1 Transcriptional and Translational Regulation	281	(4)
2.1.1 EAAT2/GLT-1	281	(3)
2.1.2 EAAT1/GLAST	284	(1)
2.2 Po sttranslational Modification	285	(9)
2.2.1 Transporter Protein Maturation	286	(1)
2.2.2 Membrane Targeting and Stabilization	287	(2)
2.2.3 Transporter Protein Trafficking	289	(4)
2.2.4 Transporter Modification	293	(1)
3 Dysregulation of Glutamate Transporters	294	(2)
3.1 Dysregulation Through Altered Transcriptional Regulation	295	(1)
3.2 Dysregulation Through Altered Transporter Targeting	296	(1)
3.3 Dysregulation Through Altered Transporter Modification	296	(1)
4 Conclusions	296	(1)
References	297	(8)
Regulation of Vesicular Monoamine and Glutamate Transporters by Vesicle-Associated Trimeric G Proteins: New Jobs for Long-Known Signal Transduction Molecules	305	(22)
I. Brunk, M. Höltje, B. von Jagow, S. Winter, J. Sternberg, C. Blex, I. Pahner, G. Ahnert-Hilger
1 Introduction	306	(1)
2 Secretory Vesicles and Their Neurotransmitter Transporters	306	(3)
2.1 Vesicular Monoamine Transporters	307	(1)
2.2 Vesicular Glutamate Transporters	307	(2)
3 Factors Influencing Transmitter Content of Individual Vesicles	309	(1)
4 Heterotrimeric G Proteins on Secretory Vesicles	310	(2)
5 Differences in the Regulation of VMAT and VGLUT Activities	312	(8)
5.1 The Role of the Electrochemical Gradient	312	(2)
5.2 Gαol and Gαq as Modulators of Vesicular Filling	314	(14)
5.2.1 G Protein-Mediated Regulation of VMAT Activity	314	(3)
5.2.2 Gαol Regulates VGLUT Activity by Changing the Chloride Dependence of the Transporter	317	(3)
6 Conclusions	320	(1)
References	321	(6)
Human Genetics and Pharmacology of Neurotransmitter Transporters	327	(46)
Z. Lin, B.K. Madras
1 The Human Dopamine Transporter (SLC6A3)	328	(15)
1.1 Introduction	328	(3)
1.1.1 DAT Regulation and Adaptation	329	(1)
1.1.2 Transient Effects	330	(1)
1.1.3 DAT Regulation and the DAT Gene	330	(1)
1.2 DAT Genomic Variants	331	(3)
1.2.1 Introduction	331	(2)
1.2.2 Coding Region Variants	333	(1)
1.2.3 Non-coding Region Variants	333	(1)
1.3 DAT Protein Variants	334	(5)
1.4 Variations in DAT Expression Levels	339	(1)
1.5 DAT Association with Human Diseases	340	(3)
2 The Human Serotonin Transporter (SLC6A4)	343	(8)
2.1 Introduction	343	(1)
2.2 SERT Genomic Variants	344	(3)
2.2.1 Introduction	344	(1)
2.2.2 Coding Region Variants	344	(1)
2.2.3 Non-coding Variants	344	(3)
2.3 SERT Protein Variants	347	(1)
2.4 Variations in SERT Expression Levels	348	(2)
2.5 SERT Association with Human Diseases	350	(1)
3 The Human Norepinephrine Transporter (SLC6A2)	351	(5)
3.1 Introduction	351	(1)
3.2 NET Genomic VARIANTS	352	(2)
3.2.1 Non-coding Region Variants	352	(2)
3.2.2 Coding Region Variants	354	(1)
3.3 NET Protein Variants	354	(1)
3.4 Variations in hNET Expression Levels	355	(1)
3.5 NET Association with Human Diseases	356	(1)
4 Transporter Gene Knockout Mice: Implications	356	(1)
5 Summary	357	(1)
References	357	(16)
ADHD and the Dopamine Transporter: Are There Reasons to Pay Attention?	373	(44)
M.S. Mazei-Robison, R.D. Blakely
1 Overview of ADHD	374	(6)
1.1 Diagnosis and Prevalence of ADHD	374	(1)
1.2 Cognitive Deficits in ADHD, the Search for Endophenotypes	375	(2)
1.3 Treatment of ADHD	377	(3)
2 The Human Dopamine Transporter	380	(8)
2.1 Cloning the hDAT Gene	380	(3)
2.2 DAT Protein: Structure/Function	383	(2)
2.3 DAT Protein: Regulation	385	(1)
2.4 DAT Protein: Pharmacological Impact on Transporter Regulation	386	(2)
3 DAT Transgenics as Animal Models of ADHD	388	(2)
3.1 DAT Knockout Mice as a Model of ADHD	388	(1)
3.2 DAT Knockdown Mice as a Model of ADHD	389	(1)
4 Neuroimaging DAT in Human Subjects	390	(4)
4.1 DAT in Adult ADHD Subjects	390	(2)
4.2 DAT in Children with ADHD	392	(1)
4.3 Influence of DAT 3'VNTR on DAT Levels	393	(1)
5 Genetic Linkage in ADHD and the Impact of DAT Gene Variants	394	(9)
5.1 ADHD Linkage Studies	394	(2)
5.2 Association Studies of hDAT and ADHD	396	(2)
5.3 DAT 3'VNTR and Response to Methylphenidate	398	(1)
5.4 Investigation of hDAT Coding Variants in ADHD	399	(4)
References	403	(14)
Inactivation of 5HT Transport in Mice: Modeling Altered 5HT Homeostasis Implicated in Emotional Dysfunction, Affective Disorders, and Somatic Syndromes	417	(40)
K.P. Lesch, R. Mössner
1 Introduction	418	(3)
2 Basic Features of 5HT Transporter Gene Inactivation	421	(9)
2.1 Neurochemistry	421	(1)
2.2 Receptor Expression and Function	422	(2)
2.3 Electrophysiology	424	(1)
2.4 Heterologous 5HT Clearance	425	(1)
2.5 Modeling Anxiety- and Depression-Like Behavior	426	(2)
2.6 5HT1A Receptor in Anxiety and Depression	428	(2)
3 Brain Development and Plasticity	430	(2)
3.1 Somatosensory Cortex and Visual System	430	(1)
3.2 Dentate Gyrus and Neurogenesis	431	(1)
4 Gene-Gene Interaction	432	(2)
4.1 5HT Transporter, Monoamine Oxidase A, and 5HT1B Receptor	432	(1)
4.2 5HT Transporter and Brain-Derived Neurotrophic Factor	433	(1)
5 5HTT Inactivation as a Model for Serotonin-Related Somatic Disorders	434	(3)
5.1 Primary Pulmonary Hypertension	435	(1)
5.2 Irritable Bowel Syndrome	435	(1)
5.3 Multiple Sclerosis	436	(1)
5.4 Bone Growth	437	(1)
5.5 Neuropathic Pain	437	(1)
6 Alcohol and Other Substances of Abuse	437	(2)
7 Linking 5HTT to Affective Spectrum Disorders	439	(3)
7.1 Genetic Epidemiology	439	(1)
7.2 Molecular Genetics	440	(1)
7.3 Anxiety- and Depression-Related Traits	441	(1)
8 Gene-Environment Interaction	442	(2)
9 Molecular Imaging of Emotionality: A Risk Assessment Strategy for Depression?	444	(3)
References	447	(10)
Lessons from the Knocked-Out Glycine Transporters	457	(28)
J. Gomeza, W. Armsen, H. Betz, V. Eulenburg
1 Neurotransmitter Functions of Glycine in the CNS	458	(1)
2 GlyTs Are Members of the Na+/Cl-Dependent Transporter Family	459	(5)
2.1 G1yT Gene Structures	459	(1)
2.2 G1yT Protein Structure	460	(2)
2.3 Glycine Uptake: Electrogenic Properties and Transport Mechanism	462	(1)
2.4 Plasma Membrane Localization and Modulation of GlyTs	463	(1)
3 Distribution of GlyTs in the CNS	464	(3)
3.1 Tissue and Cellular Distribution	464	(2)
3.2 Transcriptional Control	466	(1)
4 Functional Roles of GlyTs	467	(8)
4.1 Generation of G1yT-Deficient Mice	467	(1)
4.2 GlyTs Are Essential for Vital Postnatal Functions	468	(1)
4.3 Essential Functions of GlyTs at Glycinergic Synapses	469	(2)
4.4 Pharmacology of GlyTs	471	(2)
4.5 Function of GlyTs at Glutamatergic Synapses	473	(2)
4.5.1 Pharmacological Studies In Vitro	473	(1)
4.5.2 Pharmacology and Genetics In Vivo	474	(1)
5 GlyTs and Human Diseases	475	(2)
5.1 G1yT Genes: Candidate Disease Loci?	475	(1)
5.2 GlyTs as Potential Drug Targets	476	(1)
6 Conclusions and Perspectives	477	(1)
References	478	(7)
The Norepinephrine Transporter in Physiology and Disease	485	(40)
H. Bönisch, M. Brüss
1 Introduction	486	(1)
2 Properties, Physiology and Pharmacology of the NET	487	(6)
2.1 Basic Properties and Mechanisms of Transport	487	(5)
2.1.1 Co-substrates and Direction of Transport	489	(2)
2.1.2 NET Inhibitors	491	(1)
2.2 Physiological Importance and Knockout of the NET	492	(1)
3 Tissue Expression	493	(1)
4 Regulation of NET Function and Expression	494	(3)
5 Structure-Function Relationship	497	(4)
6 Gene Structure, Promoter and Alternative Splicing	501	(1)
7 hNET: Significance in Disease, Therapy and Diagnosis	502	(10)
7.1 Genetic Variations	502	(2)
7.2 NET and Dysautonomia	504	(1)
7.3 NET and Hypertension	505	(1)
7.4 NET and Myocardial Ischemia	505	(1)
7.5 NET and Obesity	506	(1)
7.6 NET and Anorexia Nervosa	506	(1)
7.7 NET and ADHD	507	(1)
7.8 NET and Depression	508	(1)
7.9 NET and Addiction	509	(1)
7.10 NET and Pain	510	(1)
7.11 NET Ligands in Diagnosis and Therapy	511	(1)
References	512	(13)
The High-Affinity Choline Transporter: A Critical Protein for Sustaining Cholinergic Signaling as Revealed in Studies of Genetically Altered Mice	525	(20)
M.H. Bazalakova, R.D. Blakely
1 CHT Function and Regulation	526	(5)
1.1 HACU and Cholinergic Neurotransmission	526	(2)
1.2 Pharmacological and Behavioral Modulation of HACU	528	(1)
1.3 Cloning the CHT Gene	529	(1)
1.4 CHT Provides the Molecular Basis of HACU Regulation	530	(1)
2 CHT and Genetic Mouse Models of Cholinergic Dysfunction	531	(6)
2.1 CHT Is Required for Survival: CHT Homozygosity Is Lethal	531	(3)
2.2 CHT Is Upregulated in the AChE-/- Mouse	534	(1)
2.3 CHT Is Also Upregulated in the AChE Transgenic Mouse	535	(1)
2.4 CHT Upregulation Provides Mechanism of Compensation in ChAT+/- Mice	536	(1)
2.5 CHT Downregulation in α3-/- Mice	537	(1)
3 CHT+/- Mice as Models of Cholinergic Dysfunction	537	(3)
3.1 Functional Compensation and Normal Basal Behaviors in CHT+/- Mice	538	(1)
3.2 Physical and Pharmacological Challenges Reveal Motor Phenotypes in CHT+/- Mice	538	(1)
3.3 Muscarinic Expression Is Altered in CHT+/- Mice	539	(1)
References	540	(5)
Subject Index	545