title: Functional analysis of upstream common polymorphisms of the dopamine transporter gene.
abstract: The human dopamine transporter (DAT, SLC6A3) has been extensively investigated because of its potential involvement in neuropsychiatric disorders. The core elements responsible for its transcription have been identified. A regulatory role for certain genomic variants upstream to the core promoter is known. Recently, other single-nucleotide polymorphisms (SNPs) have been identified in this region and are thought to be associated with schizophrenia and bipolar I disorder. Hence, we have investigated the impact of common SNPs in a 2.8-kilobase region flanking the core promoter region (-2.7 to +63 base pair) in the neuroblastoma cell line SH-SY5Y. Haplotypes generated by site-directed mutagenesis revealed varying impact of individual SNPs on promoter activity using dual luciferase assays. In silico analyses also predicted allele-specific binding of transcription factors for some of these SNPs. Though electrophoretic mobility shift assays indicated several factors that appeared to bind to specific sites within this region, allele-specific binding was not detected for any SNP apart from rs3756450. We have thus identified novel putative regulatory domains flanking the core promoter of DAT that merit further investigation.
authors.affiliation: Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811 O'Hara Street, Pittsburgh, PA 15213, USA.
authors.forename: Mikhil N
authors.initials: MN
authors.lastname: Bamne
authors.forename: Michael E
authors.initials: ME
authors.lastname: Talkowski
authors.forename: Kodavali V
authors.initials: KV
authors.lastname: Chowdari
authors.forename: Vishwajit L
authors.initials: VL
authors.lastname: Nimgaonkar
mesh_terms: D000483:Alleles; D045744:Cell Line, Tumor; D002875:Chromosomes; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D024202:Electrophoretic Mobility Shift Assay; D005091:Exons / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D006239:Haplotypes; D006801:Humans; D009447:Neuroblastoma; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D050436:Regulatory Elements, Transcriptional / Q000235:genetics; D012559:Schizophrenia / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D024363:Transcription Initiation Site
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; C493214:SLC6A3 protein, human; D014157:Transcription Factors