Cytosolic and Nuclear Hormone Receptors
Start with the big picture
Intracellular hormones act primarily through the nuclear receptor superfamily, whose members function as ligand-activated transcription factors. Cytosolic receptors are initially associated with HSP90; ligand binding leads to receptor activation, dimerization, and movement into the nucleus. Other receptors are already associated with chromatin before ligand binds. Their shared structural regions support DNA binding and ligand recognition. Following ligand binding, conformational changes promote coactivator recruitment and binding to hormone response elements, altering transcription. These gene-expression effects develop more slowly than rapid signaling but can be sustained. The topic also connects receptor behavior to selective modulators, receptor mutation syndromes, and cross-talk with pathways including MAPK, PI3K/AKT, and NF-κB.
What you'll learn
- Distinguish cytosolic receptors from receptors already bound to chromatin.
- Describe the major regions of nuclear receptor structure and their functions.
- Trace how ligand binding leads to transcriptional regulation.
- Identify how selective modulators, receptor mutations, and signaling cross-talk affect hormone responses.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
