US Patent 7455988 Inducible eukaryotic expression system

Compositions and methods for the inducible expression of genes in eukaryotic cells. Expression of a nucleotide sequence of interest is controlled by a regulatory fusion protein that consists of a transcription blocking domain and a legends-binding domain. When the cognate ligand for the ligand-binding domain is present, transcription of the nucleotide sequence of interest is blocked. Upon removal of the cognate ligand, the nucleotide sequence of interest is transcribed. The method is useful for large scale production of a desired product in eukaryotic cells.