title: A conserved asparagine residue in transmembrane segment 1 (TM1) of serotonin transporter dictates chloride-coupled neurotransmitter transport.
abstract: Na(+)- and Cl(-)-dependent uptake of neurotransmitters via transporters of the SLC6 family, including the human serotonin transporter (SLC6A4), is critical for efficient synaptic transmission. Although residues in the human serotonin transporter involved in direct Cl(-) coordination of human serotonin transport have been identified, the role of Cl(-) in the transport mechanism remains unclear. Through a combination of mutagenesis, chemical modification, substrate and charge flux measurements, and molecular modeling studies, we reveal an unexpected role for the highly conserved transmembrane segment 1 residue Asn-101 in coupling Cl(-) binding to concentrative neurotransmitter uptake.
authors: Departments of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548; Department of Pharmacology, Physiology, and Therapeutics, University of North Dakota, Grand Forks, North Dakota 58203. Electronic address: keith.henry@med.und.edu.
authors: L Keith
authors: LK
authors: Henry
authors: Departments of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548.
authors: Hideki
authors: H
authors: Iwamoto
authors: Departments of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548.
authors: Julie R
authors: JR
authors: Field
authors: Chemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548.
authors: Kristian
authors: K
authors: Kaufmann
authors: Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548; Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548.
authors: Eric S
authors: ES
authors: Dawson
authors: Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520-8066.
authors: Miriam T
authors: MT
authors: Jacobs
authors: Department of Pharmacology, Physiology, and Therapeutics, University of North Dakota, Grand Forks, North Dakota 58203.
authors: Chelsea
authors: C
authors: Adams
authors: Department of Pharmacology, Physiology, and Therapeutics, University of North Dakota, Grand Forks, North Dakota 58203.
authors: Bruce
authors: B
authors: Felts
authors: Institute for Biocomplexity and Informatics, Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
authors: Igor
authors: I
authors: Zdravkovic
authors: Department of Pharmacology, Physiology, and Therapeutics, University of North Dakota, Grand Forks, North Dakota 58203.
authors: Vanessa
authors: V
authors: Armstrong
authors: Chemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548.
authors: Steven
authors: S
authors: Combs
authors: Departments of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548.
authors: Ernesto
authors: E
authors: Solis
authors: Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520-8066.
authors: Gary
authors: G
authors: Rudnick
authors: Institute for Biocomplexity and Informatics, Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
authors: Sergei Y
authors: SY
authors: Noskov
authors: Departments of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548; Center for Molecular Neuroscience, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548.
authors: Louis J
authors: LJ
authors: DeFelice
authors: Departments of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548; Chemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548.
authors: Jens
authors: J
authors: Meiler
authors: Departments of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548; Center for Molecular Neuroscience, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548; Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548. Electronic address: randy.blakely@vanderbilt.edu.
authors: Randy D
authors: RD
authors: Blakely
mesh_terms: D000818:Animals; D001216:Asparagine / Q000737:chemistry*; D002712:Chlorides / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry; D004594:Electrophysiology / Q000379:methods; D006367:HeLa Cells; D006801:Humans; D007477:Ions; D016297:Mutagenesis, Site-Directed; D018377:Neurotransmitter Agents / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010957:Plasmids / Q000378:metabolism; D051381:Rats; D012701:Serotonin / Q000378:metabolism; D050486:Serotonin Plasma Membrane Transport Proteins / Q000737:chemistry*; D014982:Xenopus laevis
chemical_list: D002712:Chlorides; D007477:Ions; D018377:Neurotransmitter Agents; D050486:Serotonin Plasma Membrane Transport Proteins; D012701:Serotonin; D001216:Asparagine; D003545:Cysteine; D009638:Norepinephrine