Patent US 6,806,359

The present invention provides substantially pure DNA's comprised of sequences which encode proteins having the hormone-binding and/or transcription-activating characteristics of a glucocorticoid receptor, a mineralocorticoid receptor, or a thyroid hormone receptor. The invention also provides various plasmids containing receptor sequences which exemplify the DNA's of the invention. The invention further provides receptor proteins, including modified functional forms thereof, expressed from the DNA's (or mRNA's) of the invention.In addition to novel receptor DNA, RNA and protein compositions, the present invention involves a bioassay for determining the functionality of a receptor protein. By using our bioassay system we have discovered that a necessary and sufficient condition for activation of transcription of a gene (G), whose transcription is activated by hormones complexed with receptors, is the presence of the hormone and its receptor in the cell (C) where (G) is located. As a result of that discovery we have also invented new methods for producing desired proteins in genetically engineered cells. Two of these methods are methods of the present invention. The first is a method for inducing transcription of a gene whose transcription is activated by hormones complexed with the receptors. The second is a method for engineering a cell and increasing and controlling production of a protein encoded by a gene whose transcription is activated by hormones complexed with receptor proteins.