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A nuclear receptor responding to glucocorticoid ligands, with regulated localization and recruitment of transcriptional partners.

Ligand-dependent regulation changes nuclear activity and interaction with DNA-associated factors. Because the receptor directly connects a small-molecule hormone to gene regulation, its response can include delayed changes requiring transcription and protein synthesis. ^[ref]

A steroid hormone crosses the lipid bilayer and binds an intracellular nuclear receptor. For a cytoplasmic glucocorticoid receptor, ligand binding alters association with molecular chaperones, exposes nuclear-targeting functions and promotes accumulation in the cell nucleus. Other steroid hormone receptors already have substantial nuclear localization. The activated receptor binds specific hormone response elements in DNA, often as a dimer, and changes recruitment of transcription coactivators or transcription corepressors. These factors alter local chromatin and recruitment or activity of the RNA polymerase II machinery. The result is selective activation or repression of target genes, followed by altered messenger RNA and protein abundance; the hormone itself does not act as an RNA polymerase or directly rewrite the DNA sequence.

Progesterone is a steroid hormone produced prominently by the corpus luteum after ovulation and by the placenta during pregnancy. It helps transform and maintain the endometrium in a state that supports implantation and subsequent pregnancy. Its withdrawal, alongside other hormonal changes, contributes to menstruation when pregnancy is not established.^[ref]

Like other steroid signals, progesterone can act through a nuclear receptor to change gene expression. Its effect is therefore not merely the presence of a substance in blood: transport, receptor availability and tissue state shape the response. A post-ovulatory progesterone rise and an estrogen-driven proliferative phase describe different parts of the coordinated ovarian and uterine cycle.

A signalling derivative of vitamin A involved in stage- and tissue-dependent patterning.

It can bind nuclear receptors that regulate transcription, connecting a vitamin-derived signal to developmental gene programmes. Local synthesis and removal help determine where cells receive the signal. A measured concentration pattern and the responding tissue’s competence are therefore separate parts of a patterning mechanism. ^[ref]

A hormone based on a steroid scaffold. Many act through an intracellular nuclear receptor to regulate gene expression.