Sequences distal to the AP1/E box motif are involved in the cell type-specific expression of the rat tyrosine hydroxylase gene.
In order to define cell type-specific elements associated with the catecholamine biosynthetic enzyme, tyrosine hydroxylase (TH), transient transfections of promoter deletion constructs were used to test relative reporter-gene activities in TH-expressing and -nonexpressing cell lines. Such assays demonstrated that a region between -503 and -578 contributed to rat TH promoter activity in the pheochromocytoma cell line PC12. Deletion of these sequences resulted in a 66% loss in cell type-specific activity. Mutations within the E box/dyad symmetry element (CAGGTGCCTGTGACAGTG) did not affect the basal and cell type-specific pattern of expression exhibited by the rat TH promoter. Promoter fusion constructs between the rat TH promoter (-741 and -197) and the human TH promoter (-197 and +1) exhibited reporter-gene activities equivalent to that of wild-type -741 rat TH constructs, further demonstrating that sequence elements upstream of the rat E box/dyad symmetry are important for cell type-specific expression. Gel-shift experiments indicated that a PC12 nuclear factor could bind to a 39-bp sequence within this region in a cell type-specific manner. The size of this factor was 52 kDa as determined by UV cross-linking experiments.
Wong
S C
SC
Department of Anatomy and Neurobiology, Washington University Medical School, St. Louis, Missouri 63110.
Moffat
M A
MA
O'Malley
K L
KL
D000310:Adrenal Gland Neoplasms; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002417:Cattle; D003001:Cloning, Molecular; D015870:Gene Expression; D006801:Humans; D008156:Luciferases / Q000096:biosynthesis / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000378:metabolism; D009928:Organ Specificity; D016716:PC12 Cells; D010673:Pheochromocytoma; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D051381:Rats; D017384:Sequence Deletion; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection; D014446:Tyrosine 3-Monooxygenase / Q000096:biosynthesis* / Q000235:genetics*
D009687:Nuclear Proteins; D016755:Proto-Oncogene Proteins c-jun; D008156:Luciferases; D014446:Tyrosine 3-Monooxygenase