Mifepristone (RU486), Progesterone and Glucocorticoid receptor antagonist

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

The glucocorticoid receptor (GR) and progesterone receptor (PR) are members of the nuclear receptor family. These receptors act as transcription factors and regulate gene expression in response to hormones. They possess a characteristic modular structure comprising a ligand-binding domain a DNA-binding domain and a transcriptional activation domain. GR and PR share a significant sequence homology. The molecular mass of GR is approximately 97 kDa while PR varies between 94 and 120 kDa depending on its isoforms. These receptors are ubiquitously expressed across various tissues with GR highly present in immune metabolic and central nervous systems and PR predominantly in reproductive tissues.

Biological function summary

These receptors play important roles in mediating the effects of glucocorticoids and progesterone. GR modulates inflammatory responses and processes related to stress while PR regulates reproductive functions like menstrual cycle and pregnancy. GR can form complexes with heat shock proteins which assist in maintaining its inactive state in the absence of ligand. PR on the other hand controls gene networks critical for reproductive tissue development and function. These receptors functioning predominantly as part of nuclear receptor complexes bind specific hormone responsive elements on DNA to exert their biological effects.

Pathways

GR and PR are integral to several key biological pathways. GR is a central component of the hypothalamic-pituitary-adrenal (HPA) axis influencing metabolic and stress response pathways. It interacts with proteins like NF-κB inhibiting inflammatory pathway signaling. PR is a critical player in the reproductive signaling pathway interacting with other receptors like estrogen receptor to regulate genes associated with reproductive organ development and function. Both receptors highlight their roles in maintaining physiological homeostasis through these pathways.

Variations or dysfunctions in GR and PR contribute to various health conditions. Dysregulation of GR is associated with disorders such as Cushing's syndrome and Addison's disease reflecting its role in steroid hormone balance. Conversely altered PR function links to reproductive disorders like endometriosis and certain breast cancers pointing out its role in estrogen-mediated pathways. During these disorders GR and PR often interact distinctively with other proteins such as steroidogenic factor 1 and AP-1 making them potential targets for therapeutic interventions.