GLOSSARY

Intracellular Hormone Receptors
Intracellular hormone receptors operate within the cytoplasm or nucleus. Many belong to the nuclear receptor superfamily and respond to steroids, thyroid hormone or other ligands that can reach the intracellular receptor environment.

Receptor location varies

Some steroid receptors change location and regulatory interactions after ligand binding. Thyroid hormone receptors often associate with nuclear DNA and regulatory partners before ligand arrives. A universal sequence of cytoplasmic binding followed by nuclear entry would therefore be inaccurate.

Access requires more than solubility

Cellular transport, local hormone conversion and binding proteins influence exposure. Thyroid hormone transporters are particularly important, showing that a lipid-soluble signal does not always simply diffuse freely into every cell.

Functional result

Receptor activation can change transcription through response elements and cofactors. Effects vary with cell identity and chromatin state. The same blood concentration can consequently support different responses across organs and stages of development.