Sp1 and Sp3 activate transcription of the human dopamine transporter gene.
The dopamine transporter is a plasma membrane protein that controls extracellular concentrations of the neurotransmitter dopamine. The physiological importance of the DAT provides the impetus for studies aimed at understanding the molecular mechanisms underlying regulation of the DAT gene. In this study, we identified a DAT-expressing neuroblastoma cell line (SK-N-AS) and employed it to investigate the transcriptional regulation of the human DAT gene. Two GC boxes (located at -130 and -60, respectively, relative to the transcriptional start site) were identified as important cis-acting elements mediating DAT promoter activity in dopaminergic SK-N-AS cells. Utilizing Sp-deficient Drosophila Schneider line (SL-2) cells, we showed that both Sp1 and Sp3 are strong activators of DAT transcriptional activity. Differential binding of Sp1 and Sp3 to the two GC boxes was demonstrated by electrophoretic mobility shift assays and super-shift assays. Our results indicate that the Sp1 family of proteins plays an important role in controlling the expression of the dopamine transporter gene within dopaminergic neurons.
Wang
Jun
J
Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
Bannon
Michael J
MJ
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000502:physiology*; D050483:Dopamine Plasma Membrane Transport Proteins; D004331:Drosophila melanogaster; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D016329:Sp1 Transcription Factor / Q000502:physiology*; D051705:Sp3 Transcription Factor; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*
D004268:DNA-Binding Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493214:SLC6A3 protein, human; C497121:SP3 protein, human; C493215:Slc6a3 protein, mouse; D016329:Sp1 Transcription Factor; C497122:Sp3 protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors; D051705:Sp3 Transcription Factor