Progesterone Receptor Antibody, Clone SP2

The steroid hormone progesterone is a central coordinator of the female reproductive system. Progesterone effects are mediated through the progesterone receptor (PR), a member of the nuclear receptor superfamily of transcription factors. There are 2 isoforms (PR-A and PR-B) of this receptor that are encoded by a single gene. PR-B differs from PR-A in that PR-B has an additional 164 amino acids located at the N-terminus of the protein. Upon binding of a ligand to the receptor, there is a conformational change that allows the receptor to bind to specific DNA sequences and act as a molecular switch to turn on transcriptional activity. Expression of the PR is an important prognostic marker in breast cancer with the presence of PR correlated with better prognosis and the likelihood of response to hormonal therapy. The SP2 rabbit monoclonal antibody reacts with both isoforms of the human PR.