Control of biosynthesis and post-transcriptional modification of the progesterone receptor

The rabbit progesterone receptor undergoes dual regulation at the level of transcription: positive by estrogens and negative by progestins. The two aspects of this regulation are mediated by a single intragenic estrogen-responsive element. Estrogen receptor binding to this element has been demonstrated but progestin down-regulation does not proceed through DNA binding of the progesterone receptor. This result suggests some and of protein-protein interaction-direct or indirect-between estrogen and progesterone receptors