Dual reporter systems in yeast and mammalian cells for assessing progesterone receptor modulators

In the present study we describe the set-up of a new one-hybrid reporter ge ne assay in Saccharomyces cerevisiae composed of the human progesterone rec eptor fused to the DNA-binding domain of the yeast transcriptional activato r Gal4. This assay allows the convenient estimation of receptor mediated pr ogestogenic as well as antiprogestogenic actions of compounds. The inductio n of the beta-galactosidase reporter gene expression correlated well with t he progesterone receptor affinity and the concentration of the progestins t ested. The results corresponded to those obtained from a reporter gene assa y in the cancer cell line CV-1 and in vitro binding experiments using rabbi t uterus cytosol. In both the yeast and CV-1 cells the activity of antiprog estins was detectable by inhibition of the progestin-induced reporter gene expression. Secondary reporter genes under the transcriptional control of r eceptor unrelated promoters have been introduced into yeast and mammalian t est strains to distinguish between specific receptor mediated antihormone a ctions and nonspecific effects on cellular metabolism. J. Cell. Biochem. 73 :126-136, 1999. (C) 1999 Wiley-Liss, Inc.