G proteins

(redirected from guanine nucleotide-binding protein)

G pro·teins

intracellular membrane-associated proteins activated by several (for example, β-adrenergic) receptors; they serve as second messengers or transducers of the receptor-initiated response to intracellular elements such as enzymes to initiate an effect. These proteins have a high affinity for guanine nucleotides and hence are named G proteins.

G proteins

Cell messengers that relay signals from over 1000 different cell membrane receptors to many different intracellular effectors such as enzymes and ion channels. G proteins have three subunits, alpha, beta, and gamma, each coded for by a different gene, selected from a total of 34 genes. G protein function is switched on and off by the binding and hydrolysis of guanosine triphosphate to the alpha subunit which is loosely attached to the others. Binding causes the beta and gamma fragments to separate as a dimer and to activate downstream effectors.
References in periodicals archive ?
A type of achromatopsia previously identified as ACHM1 was later found to be the same as ACHM3 caused by cyclic nucleotide-gated channel beta-3 (CNGB3) gene (MIM 605080).8 Among other genes are included cyclic nucleotide-gated channel alpha-3 (CNGA3; MIM 600053) causing ACHM29, Guanine nucleotide-binding protein G subunit [alpha]-2 (GNAT2; MIM 139340) causing ACHM4, 10 phosphodiesterase 6C (PDE6C; MIM 613093) causing ACHM5, 11 cone inhibitory phosphodiesterase 6H (PDE6H; MIM 601190) causing ACHM612 and activating transcription factor 6 (ATF6; MIM 605537) causing ACHM7.13 The current study was planned to report two Pakistani families that were initially evaluated as having nystagmus phenotype.
UM is genetically characterized by frequent, mutually exclusive mutations in guanine nucleotide-binding protein G(q) subunit alpha (GNAQ) and guanine nucleotide-binding protein subunit alpha-11 (GNA11) which can be detected in 83% of patients with UM [12].
Guanine nucleotide-binding protein subunit alpha-s (Gn[alpha]s) is closely related to the alpha subunits of the s class.
Measurement of guanine nucleotide-binding protein activation by [A.sub.1] adenosine receptor agonists in bovine brain membranes: stimulation of guanosine-5'-O-(3-[[S.sup.35]]thio)triphosphate binding.
Differential susceptibility of guanine nucleotide-binding proteins to pertussis toxin-catalyzed ADP-ribosylation in brain membranes of two congeneric marine fishes.
In APC, volatile anaesthetics appear to mediate their protection in cardiomyocytes by selectively priming sarcolemmal and mitochondrial adenosine-triphosphate-sensitive potassium channels through triggering a complex signal cascade involving protein kinase C, protein tyrosine kinase, second messenger signal systems such as guanine nucleotide-binding proteins and by the influence on [Ca.sup.2+] homeostasis and the generation of reactive oxygen species or nitric oxide (NO) through parallel pathways.
Guanine nucleotide-binding proteins (G proteins) are the important second messengers among various signalling pathways.
activities, such as the citric acid cycle and the activation of guanine nucleotide-binding proteins (G-proteins), which typically switch between
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