Selective conservation of an E-protein gene promoter during vertebrate evolution

The murine E-protein gene ME1 encodes a nontissue-specific, helix-loop-heli x transcription factor that is associated with morphological development. M E1 gene expression is regulated by a TATA-less promoter that contains multi ple Spl consensus elements, E-boxes, and a novel transcription initiation s ite. In this study, we compared DNA homologous to the ME1 promoter from ver tebrate species ranging from frog to human. A region of striking sequence s imilarity was identified in a region corresponding to the ME1 transcription initiation site (ME1 Inr), Within this region, a poly d(A) tract and a 9-b p inverted repeat (5'-GTCCGCCTG) were highly conserved in all species that were examined. Protein complexes that recognized these DNA elements sere pr esent among distant vertebrates (frog, chick, monkey and human), and were a ble to bend the ME1 Inr to a similar extent (similar to 60 degrees) as the previously described murine MBP alpha and MBP beta proteins. Collectively, these results suggest that an ME1 Inr-like element and its associated prote ins functioned in an ancestral vertebrate more than 350 million years ago, (C) 1998 Federation of European Biochemical Societies.