abstract |
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; various plasmids containing receptor sequences which exemplify these DNA's; receptor proteins, including modified functional forms thereof, expressed from the DNA's (or mRNA's); and a bioassay for determining the functionality of a receptor protein. Use of this bioassay has led to the discovery 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 cell (C) where (G) is located. As a result, two new methods for producing desired proteins in genetically engineered cells were discovered. |