Identification of a protein-binding site that mediates transcriptional response of the c- fos gene to serum factors

Abstract

Transient transcriptional activation of the c- fos gene following serum stimulation of susceptible cells requires a conserved DNA element located 300 bp 5′ to the mRNA cap site. A DNA-binding gel electrophoresis assay was used to detect a protein(s) in HeLa cell nuclear extracts that specifically binds to the 5′ activating element. The protein recognizes a region of dyad symmetry within the 5′ activating element, defined by binding competition, dimethylsulphate (DMS) interference and DNAase I and DMS protection studies. A single 22 bp synthetic copy of the dyad symmetry element will both compete efficiently for protein binding and restore serum regulation to c- fos H genes that lack the 5′ activating element.