Effect of alpha-synuclein on the promoter activity of tyrosine hydroxylase gene.
OBJECTIVE
To approach the associated mechanism by which alpha-synuclein (alpha-Syn) might regulate the metabolism of dopamine.


METHODS
A DNA fragment, located at -495 to +25 of the human tyrosine hydroxylase (TH) gene, was amplified by PCR and inserted into the pGL(3)-Basic luciferase reporter vector. The recombinant plasmid pGL(3)-THprom was transfected into a dopaminergic cell line MES23.5 or a alpha-Syn over-expressed MES23.5 (named MES23.5/halpha-Syn(+)). The promoter activity was detected by the Dual Luciferase Assay System.


RESULTS
The luciferase activities in the MES23.5 cells transfected with pGL(3)-Basic, pGL(3)-THprom, and pGL(3)-Control vectors were 5.60+/-0.67, 26.80+/-4.11, and 32.90+/-4.75, respectively. On the other hand, the luciferase activity of pGL(3)-THprom in the MES23.5 (26.80+/-4.11) was significantly higher than that in the MES23.5/halpha-Syn(+) (14.40+/-0.61) (P<0.01).


CONCLUSIONS
These results indicate that the - 495 to +25 region in the TH gene possesses promoter activity for controlling the gene expression, and that alpha-Syn may negatively regulate the metabolism of dopamine by affecting the function of TH promoter as a trans-acting factor.
Gao
Nan
N
Department of Neurobiology, Beijing Institute of Geriatrics, Xuanwu Hospital of Capital University of Medical Sciences, Beijing 100053, China.
Li
Yao-Hua
YH
Li
Xin
X
Yu
Shun
S
Fu
Gui-Lian
GL
Chen
Biao
B
D000818:Animals; D045744:Cell Line, Tumor; D004298:Dopamine / Q000096:biosynthesis*; D015536:Down-Regulation / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics*; D017930:Genes, Reporter / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics; D006825:Hybridomas; D008156:Luciferases / Q000235:genetics; D051379:Mice; D009474:Neurons / Q000378:metabolism*; D010300:Parkinson Disease / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D011401:Promoter Regions, Genetic / Q000235:genetics*; D051381:Rats; D050436:Regulatory Elements, Transcriptional / Q000235:genetics; D013378:Substantia Nigra / Q000378:metabolism / Q000503:physiopathology; D014162:Transfection; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics*; D051844:alpha-Synuclein / Q000235:genetics*
D051844:alpha-Synuclein; D008156:Luciferases; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine