Identification and purification of a Saccharomyces cerevisiae protein with the DNA binding specificity of mammalian activating transcription factor.

Activating transcription factor (ATF) is a mammalian transcriptional activator, which is involved in the expression of many viral E1a-inducible and cellular cAMP-inducible genes. Here we identify from the yeast Saccharomyces cerevisiae a previously uncharacterized protein whose DNA binding specificity is like mammalian ATF. We purify this protein (yATF) and show that it is a 66-kDa polypeptide. Finally, we demonstrate that a mammalian ATF site can function as an upstream activating sequence in S. cerevisiae. Taken together, our results suggest that yATF is a previously uncharacterized S. cerevisiae transcriptional activator.