Patent ID: 8492088

Claim:
A yeast cell comprising: (i) a yeast transcription modulating system comprising a first heterologous nucleic acid expression system encoding a recombinant nuclear receptor polypeptide comprising a ligand-binding domain operably linked to a DNA-binding domain and optionally to a flexible hinge domain, wherein the recombinant nuclear receptor polypeptide, when expressed in the yeast cell in the presence of a nuclear receptor ligand specifically binding to the recombinant nuclear receptor polypeptide, activates expression of a selective genetic locus; and a second heterologous nucleic acid expression system encoding an adapter polypeptide comprising a coactivator domain operably linked to a yeast transcriptional activator, and wherein the first heterologous nucleic acid expression system and the second heterologous nucleic acid expression system are each independently encoded by individual heterologous polynucleotides or are encoded by the same heterologous polynucleotide; (ii) a nuclear receptor ligand generating system comprising a third heterologous nucleic acid expression system encoding a heterologous enzyme system for the generation of a nuclear receptor ligand from a substrate, wherein the nuclear receptor ligand is characterized as specifically binding to the recombinant nuclear receptor polypeptide; and (iii) a selective genetic locus expressed in the presence of the recombinant nuclear receptor polypeptide and a nuclear receptor ligand specifically bound to the recombinant nuclear receptor polypeptide.