Method for the preparation of a protein by yeasts using an inducible system, vectors and correspondence transformed strains

The present invention relates to a method for the preparation of a protein by yeasts. In particular, the method of the invention concerns transforming a yeast cell with a first DNA fragment encoding the protein and a second DNA fragment that encodes the receptor. The method further entails culturing the transformed yeast cell, and isolating the protein. The first DNA fragment is under control of elements providing for expression of the DNA fragment in yeast, which elements include a higher eukaryotic positive transcription control sequence consisting of a natural ligand responsive element activating sequence or a variant. The receptor is a natural nuclear receptor selected from the group consisting of receptors for steroids or for retinoids or for thyroid hormones or for vitamin D3. The receptor includes a first fragment that recognizes said ligand and a second fragment that binds to said transcriptional control sequence.