THE ROLES OF CRE, TRE, AND TRE-ADJACENT S1 NUCLEASE SENSITIVE ELEMENTIN THE REGULATION OF TYROSINE-HYDROXYLASE GENE PROMOTER ACTIVITY BY ANGIOTENSIN-II

The cis elements mediating activation of the tyrosine hydroxylase gene by angiotensin II were examined by transfecting tryrosine hydroxylase promoter-luciferase constructs into cultured bovine adrenal medullary cells. Angiotensin II-responsive elements are located within -54/+25- bp and -269/-55-bp promoter regions and were identified, respectively, as cyclic AMP (CRE)- and 12-O-tetradecanoylphorbol 13-acetate respons ive element (TRE)-like sequences. Unlike CRE, TRE also supports basal promoter activity. Mutations of TRE or CRE that reduced angiotensin ii stimulation abolished in vitro binding of nuclear proteins to those e lements, suggesting that proteins forming CRE- and TRE-inducible compl exes may mediate angiotensin ii stimulation. The TRE is adjacent to a dyad symmetry element. Those two sites form a common regulatory unit i n which the dyad symmetry element acts as a repressor of the TRE site. Isolated dyad symmetry element did not bind nuclear proteins in vitro . In supercoiled DNA it exhibited S1 nuclease sensitivity and was reco gnized by a DNA cruciform-specific antibody consistent with the extrus ion of a cruciform structure that overlaps with the TRE. A mutation th at abolished formation of the cruciform correlated with a loss of repr essor activity. We propose a novel model of tyrosine hydroxylase gene regulation in which functions of the TRE are modulated via structural transition in the adjacent DNA.