BIO 320 Lecture Notes - Lecture 18: Adrenergic Receptor, Cyclic Adenosine Monophosphate, Cell Membrane
Document Summary
G protein-coupled receptors (gpcrs): over 800 in humans (odor, taste, sight, etc), but not all made in the same cell. Trans-membrane receptor: binds and recognizes signal, transfers signal to cytosolic side. Trimeric g protein: transmits signal from receptor to target (or effector) protein. In all cases, these target or effector proteins are membrane-bound enzymes (e. g. , adenylyl cyclase and phospholipase c) or ion channels. E. g. , rhodopsin (for light in eye); olfactory receptors (odor); taste receptors; -adrenergic receptor (for fight or flight and other responses); acetylcholine receptor (for muscle contraction and other effects). ~30% of all commercially available drugs act as agonists or antagonists of specific gpcrs. Many other drugs affect the signaling pathways downstream of these gpcrs: e. g. , zoloft, plavix, oxycontin, etc. Trimeric g proteins function with g protein-coupled receptors (and they may or may not be associated with receptors before ligands bind receptors) G : g and gg are covalently modified with lipid molecule.
