EVIDENCE FOR THE PRESENCE OF A FUNCTIONAL TATA BOX (ATAAAA) SEQUENCE IN THE GENE FOR BOVINE ELASTIN

The wild type sequence (wt; ATAAAA) was mutated and the effects of the mutants were determined by assaying the expression of the chloramphen icol acetyltransferase (CAT)-encoding gene (cat) cloned downstream. Th e negative mutant (neg; ACGAAA) practically abolished the activities o f the 129 bp and the 416 bp elastin promoters in NIH 3T3 and neonatal rat aortic smooth muscle cells, respectively. However, when the positi ve mutant (pos; TATAAAA) was assayed in parallel experiments, there wa s enhancement of activity. The TATA box-binding protein (TBP) was show n to bind to the ATAAAA sequence and the retardation of the band was a bolished by competition assay using unlabeled wt and pos sequences, bu t not by the neg mutant. These results provide evidence for the presen ce of a functional TATA box in the gene for elastin.