Role of proline residues in the expression and function of the human noradrenaline transporter

Paczkowski, FA and Bryan-Lluka, LJ (2004) Role of proline residues in the expression and function of the human noradrenaline transporter. Journal of Neurochemistry, 88 1: 203-211. doi:10.1046/j.1471-4159.2003.02149.x


Author Paczkowski, FA
Bryan-Lluka, LJ
Title Role of proline residues in the expression and function of the human noradrenaline transporter
Journal name Journal of Neurochemistry   Check publisher's open access policy
ISSN 0022-3042
Publication date 2004-01-01
Sub-type Article (original research)
DOI 10.1046/j.1471-4159.2003.02149.x
Volume 88
Issue 1
Start page 203
End page 211
Total pages 9
Editor Brian Collier
Anthony J. Turner
Place of publication London, England
Publisher Blackwell Science
Language eng
Subject C1
320502 Basic Pharmacology
320702 Central Nervous System
270104 Membrane Biology
780105 Biological sciences
730104 Nervous system and disorders
730205 Substance abuse
730211 Mental health
Abstract The aim was to investigate the roles of proline residues in extracellular loop 2 (P172, P183, P188 and P209) and transmembrane domains 2, 5, 11 and 12 (P108, P270, P526, P551, P552 and P570) in determining noradrenaline transporter (NET) expression and function. Mutants of human NET with these residues mutated to alanine were pharmacologically characterized. Mutation of P108, P270 and P526 disrupted cell surface expression, from [H-3]nisoxetine binding and confocal microscopy data. Mutations of P526, P551 and P570 reduced transporter turnover (V-max of [H-3]noradrenaline uptake/B-max of [H-3]nisoxetine binding) by 1.5-1.7-fold compared with wild-type NET, so these residues might be involved in conformational changes associated with substrate translocation. Conversely, mutations of P172, P183, P188 and P209 increased V-max/B-max by 2-3-fold compared with wild-type, indicating that the presence of these proline residues limits turnover of the NET. The mutations had few effects on apparent affinities of substrates or affinities of inhibitors, except decreases in inhibitor affinities after mutations of the P270 and P570 residues, and increases after mutation of the P526 residue. Hence, proline residues in extracellular loop 2 and in transmembrane domains have a range of roles in determining expression and function of the NET.
Keyword Neurosciences
Affinities
Noradrenaline Transporter
Proline Residues
Site-directed Mutagenesis
Transfected Cos-7 Cells
Transporter Turnover
Human Norepinephrine Transporter
Pharmacological-properties
Serotonin Transporter
Dopamine Transporter
Mutagenesis
Proteins
Domain
Rat
Biochemistry & Molecular Biology
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collections: Faculty of Science Publications
Excellence in Research Australia (ERA) - Collection
2005 Higher Education Research Data Collection
 
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Created: Wed, 15 Aug 2007, 14:51:14 EST