Physiology 3140A Lecture Notes - Lecture 2: Liver X Receptor, Hormone Response Element, Retinoic Acid Receptor

• School: Western University
• Department: Physiology
• Course: Physiology 3140A
• Professor: John Di Guglielmo

Document Summary

Target cell responds by means of a receptor protein, which specifically binds the signal molecule and initiates a response. In intracellular receptors, ligands diffuse across membranes and bind receptors in the cytosol or nucleus after binding, translocation to the nucleus occurs. Intracellular receptors are usually carried by a carrier molecule through the blood. 3 main parts: transcription-activating domain, ligand-binding domain, dna-binding domain. When the receptor is in the inactive form, inhibitory proteins are bound to part of the ligand binding domain. Once activated by the ligand biding domain forms a tight clap around the ligand coactivator proteins help as well. Then the receptor binds the receptor-binding element and. Nuclear receptor signalling (intracellular) activates transcription of target genes. Note: ligand binding can also have the opposite effect, causing co-repressor proteins to bind to the receptor, thereby decreasing transcription. Type oxysterol, thyroid: coactivators remove the corepressors to allow for ligand binding. Ion channel-linked receptors: convert chemical signals into electrical ones.