G protein

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G protein

A cellular protein activated by the binding of an intercellular signal to its receptor on the cell membrane; the G-protein then activates the enzyme adenyl cyclase within the cell, triggering the formation of cyclic AMP and a stereotyped response.
See also: protein

G protein

a regulatory protein which becomes activated when bound to GTP and is involved in signal transduction.

G protein coupled receptor
a member of a large class of cell-surface signaling receptors that contain seven transmembrane a helices; ligand binding results in activation of a coupled trimeric G protein that then initiates intracellular signal transduction pathways.
References in periodicals archive ?
Comparative genomics of prokaryotic GTP-binding proteins (the Era, Obg, EngA, ThdF (TrmE), YchF and YihA families) and their relationship to eukaryotic GTP-binding proteins (the DRG, ARF, RAB, RAN, RAS and RHO families).
Molecular cloning of the microtubule-associated mechanochemical enzyme dynamin reveals homology with a new family of GTP-binding proteins.
Purification of heterotrimeric GTP-binding proteins from brain: identification of a novel form of Go.
Guanine nucleotide-sensitive high affinity binding of agonists to purified muscarinic receptors reconstituted with GTP-binding proteins (Gi and Go).
To better understand the link between MIH receptor occupancy and Y-organ cAMP levels, we have assessed the presence of GTP-binding proteins (G-proteins) in Y-organs of the blue crab (Callinectes sapidus).
Despite the dramatic changes induced by EPEC in the cytoskeleton, there appears to be little involvement of the Rho family of small GTP-binding proteins normally involved in cytoskeletal rearrangements (29).