Premium
Tissue‐specific DNaseI hypersensitive sites in the 5′‐flanking sequences of the tryptophan oxygenase and the tyrosine aminotransferase genes.
Author(s) -
Becker P.,
Renkawitz R.,
Schütz G.
Publication year - 1984
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1984.tb02084.x
Subject(s) - biology , gene , tyrosine aminotransferase , tyrosine , microbiology and biotechnology , tryptophan , genetics , 5' flanking region , biochemistry , enzyme , gene expression , amino acid , enzyme inducer , promoter
The genes for tryptophan oxygenase (TO) and tyrosine aminotransferase (TAT) are expressed in a tissue‐ and development‐specific manner and are regulated by glucocorticoids (TO and TAT) and glucagon or its intracellular mediator cAMP (TAT) in rat liver. We have analyzed the chromatin structure of these genes in the vicinity of the 5′ ends with regard to DNaseI hypersensitivity and have found DNaseI hypersensitive sites upstream of each of the promoters. Mapping of this region reveals three closely spaced cleavage sites near the TO promoter and a doublet of sites near the TAT promoter. In both genes additional cleavage sites are found further upstream. All hypersensitive sites of both genes are absent in kidney nuclei and therefore appear to be specific for the tissue expressing the genes. A correlation of expression and modified chromatin structure was also observed in a hepatoma cell line expressing TAT but not TO: hypersensitive sites are present in TAT but not in TO chromatin. Upon glucocorticoid induction an additional hypersensitive site is detected approximately 2 kb upstream of the TAT promoter in liver and hepatoma cells.