]'he human dopamine transporter (hDAT) plays a critical role in neurotransmission via its ability to take up dopamine into the presynaptic terminal and thereby terminate dopaminergic neurotransmission. Alteration of dopaminergic neurotransmission has been suggested to contribute to a multitude of pathological conditions including attention deficit hyperactivity disorder (ADHD). While multiple genetic studies have observed an association between hDAT and ADHD, a systematic screen of the hDAT coding region for variants such as single nucleotide polymorphisms (SNPs) that alter protein function in children with ADHD has not been conducted. The focus of this proposal is the functional impact of SNPs on hDAT function and the identification of variants, such as SNPs, in subjects with ADHD.
Specific Aims : 1) Biochemically and pharmacologically characterize previously identified nonsynonymous single nucleotide polymorphisms in the human dopamine transporter. Radioligand transport and binding, and cell surface biotinylation will be used to assess the ability of the mutant transporters to properly transport substrates, bind inhibitors and traffic to the plasma membrane. 2) Identify and characterize hDAT coding variants in subjects with attention deficit hyperactivity disorder. DNA will be isolated from subjects' buccal cells, exons will be PCR amplified and then screened for coding sequence variation in a high-throughput manner using pyrosequencing technology. This work will help to further understanding of the functional impact of coding variation in hDAT. In addition, these studies may identify an etiological pathway for ADHD, which may help to generate more effective :liagnostic criteria as well as novel therapeutics.

National Institute of Health (NIH)
National Institute of Mental Health (NIMH)
Predoctoral Individual National Research Service Award (F31)
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Special Emphasis Panel (ZRG1-F01 (20))
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Curvey, Mary F
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Vanderbilt University Medical Center
Schools of Medicine
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Moritz, Amy E; Foster, James D; Gorentla, Balachandra K et al. (2013) Phosphorylation of dopamine transporter serine 7 modulates cocaine analog binding. J Biol Chem 288:20-32
Sakrikar, Dhananjay; Mazei-Robison, Michelle S; Mergy, Marc A et al. (2012) Attention deficit/hyperactivity disorder-derived coding variation in the dopamine transporter disrupts microdomain targeting and trafficking regulation. J Neurosci 32:5385-97
Mazei-Robison, Michelle S; Bowton, Erica; Holy, Marion et al. (2008) Anomalous dopamine release associated with a human dopamine transporter coding variant. J Neurosci 28:7040-6
Hahn, M K; Blackford, J U; Haman, K et al. (2008) Multivariate permutation analysis associates multiple polymorphisms with subphenotypes of major depression. Genes Brain Behav 7:487-95
Mazei-Robison, Michelle S; Couch, R Steven; Shelton, Richard C et al. (2005) Sequence variation in the human dopamine transporter gene in children with attention deficit hyperactivity disorder. Neuropharmacology 49:724-36
Mazei-Robison, Michelle S; Blakely, Randy D (2005) Expression studies of naturally occurring human dopamine transporter variants identifies a novel state of transporter inactivation associated with Val382Ala. Neuropharmacology 49:737-49