Anti-Progesterone Receptor B Antibody, clone 250/H11 clone 250/H11, from mouse

Progesterone receptor (UniProt P06401; also known as Nuclear receptor subfamily 3 group C member 3, PR) is encoded by the PGR (also known as NR3C3) gene (Gene ID 5241) in human. The progesterone receptor (PR) is a hormone activated transcription factor, where hormone binding triggers the dissociation of heat shock and chaperone proteins from PR, leading to PR dimerization and activation. The receptor dimer then binds progestin response elements in the regulatory regions of its target genes and a multi-component complex is assembled to enable transcription. In addition, a number of kinases are also reported to regulate PR activity via phosphorylation. PR can also regulate transcription without direct DNA binding by tethering to other transcription factors, such as specificity protein 1 (Sp1) or activator protein 1 (AP-1), and modulating their transcriptional activity on target genes. PR is expressed as five isoforms, including PR-B and PR-A that are produced as a result of alternate estrogen inducible promoters within the same PGR gene. PR-A lacks the first 164 amino acids of PR-B but the two isoforms have otherwise identical sequence. PR-B and PR-A can regulate distinct subsets of target genes and studies in knockout mice suggest that PR-B predominantly regulates mammary gland development and PR-A is critical for normal uterine function.