G proteins control diverse pathways of transmembrane signaling.

摘要: Hormones, neurotransmitters, and autacoids interact with specific receptors thereby trigger a series of molecular events that ultimately produce their biological effects. These receptors, localized in the plasma membrane, carry binding sites for ligands as diverse peptides (e.g., glucagon, neuropeptides), lipids prostaglandins), nucleosides nucleotides adenosine), amines catecholamines, serotonin). do not interest directly respective downstream effector (i.e., an ion channel and/or enzyme synthesizes second messenger); rather, they control one or several target systems via activation intermediary guanine nucleotide-binding regulatory protein G protein. proteins serve signal transducers, linking extracellularly oriented to membrane-bound effectors. Traffic these pathways is regulated by GTP (on)-GDP (off) switch, which receptor. The combination classical biochemistry recombin...