This Progesterone Receptor antibody is un-conjugated
Application
Western Blotting (WB), Immunohistochemistry (IHC)
Specificity
Specific for the ~90k PR-A isoform and the ~120k PR-B isoform phosphorylated at Ser190. Immunolabeling is blocked by the phosphopeptide used as antigen but not by the corresponding dephosphopeptide.
Cross-Reactivity
Human
Purification
Protein G purified culture supernatant
Immunogen
Synthetic phospho-peptide corresponding to amino acid residues surrounding Ser190 conjugated to KLH
There is accumulating evidence to suggest that progesterone plays an essential role in the regulation of growth and differentiation of mammary glands and thus may play a key role in breast cancer (Edwards, 2005). The biological response to progesterone is mediated by two distinct forms of the human progesterone receptor (PR-A and PR-B forms). In most cell contexts, the B form functions as a transcriptional activator, whereas the A form functions as a transcriptional inhibitor of steroid hormones (Attia et al., 2000, Lin et al., 2003). Recently it has been demonstrated that there is differential hormone dependent regulation of the phosphorylation of the A and B forms of the receptor (Clemm et al., 2000) . Treatment of T47D breast cancer cells with progestin agonist increases the phosphorylation of Ser190 and Ser294 with different kinetics. These phosphorylation events may differentially affect the transcriptional activity of the receptor. Anti-Phospho Ser190 Progesterone Receptor Western blot of whole cell T47D lysate prepared from cells that had been inubated in the presence of the synthetic progestin agonist R5020 (500 nM) showing specific immunolabeling of the ~90k PR-A isoform and the ~120 PR-B isoform of the progesterone receptor phosphorylated at Ser190. The immunolabeling is specifically blocked by the phosphopeptide used as the antigen (not shown).