Structure-function relationships of the chicken progesterone receptor.

To define the functional domains of the chicken progesterone receptor (CPR) and to establish the origin of the receptor A and B proteins, we have cloned and sequenced the complete cDNA encoding the CPR. The receptor A and B proteins arise by alternate initiation of translation from a single mRNA transcript. Using deletion mutants in the receptor A cDNA, we have determined that the DNA binding and gene activator regions reside in the central portion of the protein, while the hormone binding domain is located in the C-terminal region. The target gene activator site of the receptor is modulated by interaction with the hormone binding domain.