In mammalian cells, the glucocorticoid receptor binds specifically to glucocorticoid response element (GRE) DNA sequences and enhances transcription from linked promoters. It is shown here that derivatives of the glucocorticoid receptor also enhance transcription when expressed in yeast. Receptor-mediated enhancement in yeast was observed in fusions of GRE sequences to the yeast cytochrome c1 (CYC1) promoter; the CYC1 upstream activator sequences were not essential, since enhancement was observed in fusions of GREs to mutant CYC1 promoters retaining only the TATA region and transcription startpoints. It is concluded that the receptor operates by a common, highly conserved mechanism in yeast and mammalian cells.