page_title: G protein-coupled receptor
section_title: Mechanism
hierarchical_section_title: G protein-coupled receptor / Mechanism
caption_attribution_description: English: Cartoon of GPCR Conformational Activation. Ligand binding disrupts an ionic lock between the E/DRY motif of TM-3 and acidic residues of TM-6. As a result the GPCR reorganizes to allow activation of G-alpha proteins. The side perspective is a view from above and to the side of the GPCR as it is set in the plasma membrane (the membrane lipids have been omitted for clarity). The intracellular perspective shows the view looking up at the plasma membrane from inside the cell. Based on information found in Mol. Endocrinol. 2010 24:261-274 Abbreviations, etc: GPCR domains: IL-1 to IL-3= Intracellular loops 1-3 EL-1 to EL-3= Extracellular loops 1-3 Other: G-alpha= Alpha subunit of a heterotrimeric G-protein G-beta/gamma= G-beta/gamma heterodimer of heterotrimeric G-protein The figure is based on information found in the review article "The Year In G Protein-Coupled Receptor Research" Molecular Endocrinology 24 (1): 261-274. (2010)
context_page_description: G protein-coupled receptors, also known as seven--transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptor, and G protein-linked receptors, is a large group of evolutionary related proteins that are cell surface receptor that detect molecules outside the cell and activate cellular responses. Coupling with G proteins, they are called seven-transmembrane receptors because they pass through the cell membrane seven times.
  G protein-coupled receptors are found only in eukaryotes, including yeast, choanoflagellates, and animals. The ligands that bind and activate these receptors include light-sensitive compounds, odors, pheromones, hormones, and neurotransmitters, and vary in size from small molecules to peptides to large proteins. G protein-coupled receptors are involved in many diseases.
  There are two principal signal transduction pathways involving the G protein-coupled receptors:
  the cAMP signal pathway and
  the phosphatidylinositol signal pathway.
  When a ligand binds to the GPCR it causes a conformational change in the GPCR, which allows it to act as a guanine nucleotide exchange factor.
context_section_description: The G protein-coupled receptor is activated by an external signal in the form of a ligand or other signal mediator. This creates a conformational change in the receptor, causing activation of a G protein. Further effect depends on the type of G protein. G proteins are subsequently inactivated by GTPase activating proteins, known as RGS proteins.
caption: Cartoon depicting the basic concept of GPCR conformational activation. Ligand binding disrupts an ionic lock between the E/DRY motif of TM-3 and acidic residues of TM-6. As a result, the GPCR reorganizes to allow activation of G-alpha proteins. The side perspective is a view from above and to the side of the GPCR as it is set in the plasma membrane (the membrane lipids have been omitted for clarity). The intracellular perspective shows the view looking up at the plasma membrane from inside the cell.[43]
exif: {}