DNA binding site of the growth factor-inducible protein Zif268

Abstract

Zif268, a zinc finger protein whose mRNA is rapidly activated in cells exposed to growth factors or other signaling agents, is thought to play a role in regulating the genetic program induced by extracellular ligands. We report that Zif268 has one of the characteristics of a transcriptional regulator, namely, sequence-specific binding to DNA. Zif268 synthesized in Escherichia coli bound to two sites upstream of the zif268 gene and to sites in the promoter regions of other genes. The nucleotide sequences responsible for binding were defined by DNase I footprinting, by methylation interference experiments, and by use of synthetic oligonucleotides. From these results we derived the following consensus sequence for a Zif268 high-affinity binding site: GCGTGGGGCG.