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Overview

protein G

An immunoglobulin-binding protein (60 aa) expressed in group C and G streptococci. Similar to protein A but has a higher affinity for IgG and will bind IgGs from a wider range of species. ...

G protein

G protein   Quick reference

A Dictionary of Biomedicine (2 ed.)

Reference type:
Subject Reference
Current Version:
2019

...G protein 1. The spike glycoprotein of vesicular stomatitis virus . 2. See GTP-binding proteins...

protein G

protein G   Quick reference

A Dictionary of Biomedicine (2 ed.)

Reference type:
Subject Reference
Current Version:
2019

...protein G An immunoglobulin-binding protein (60 aa) expressed in group C and G streptococci. Similar to protein A but has a higher affinity for IgG and will bind IgGs from a wider range of...

protein G

protein G   Reference library

Oxford Dictionary of Biochemistry and Molecular Biology (2 ed.)

Reference type:
Subject Reference
Current Version:
2008
Subject:
Science and technology, Life Sciences
Length:
52 words

... G a bacterial cell‐wall protein isolated from group G streptococci. Its properties and uses are similar to those of protein A , but it does not bind to IgM, IgD, or IgA; it does bind to all subclasses of human IgG, and animal immunoglobulins, with which protein A does not react...

G protein

G protein   Reference library

Oxford Dictionary of Biochemistry and Molecular Biology (2 ed.)

Reference type:
Subject Reference
Current Version:
2008
Subject:
Science and technology, Life Sciences
Length:
303 words

...of Gprotein and subunits are subscripted: thus the α subunit of Gprotein S (which activates adenylate cyclase ) is G sα ; other Gproteins include G i , which differs from G S structurally (different type of α subunit) and inhibits adenylate cyclase ; G o , a Gprotein detected by cDNA probes, of wide tissue distribution in mammals but of unclear role; G p , a Gprotein that activates phospholipase C ( see phospholipase ), release of Ca 2+ and activation via calmodulin and protein kinase C ( see also phosphatidylinositol cycle ). Binding of G αβγ ...

G protein

G protein   Quick reference

A Dictionary of Biology (8 ed.)

Reference type:
Subject Reference
Current Version:
2019
Subject:
Science and technology, Life Sciences
Length:
299 words

...G protein Any one of a group of proteins that relay signals in animal cells ( see signal transduction ). They occur on the inner surface of the plasma membrane and transmit signals from receptors on the outer surface of the cell to intracellular components. G proteins are activated by binding to GTP and become inactive when they bind GDP ( see guanosine ). Large G proteins comprise three dissimilar subunits (denoted α ‎, β ‎, and γ ‎: i.e. they are heterotrimeric), and numerous G α ‎ subunits are known. They associate with various types of cell...

protein kinase G

protein kinase G   Quick reference

A Dictionary of Biomedicine (2 ed.)

Reference type:
Subject Reference
Current Version:
2019

...protein kinase G ( PKG ) A member of the AGC kinase family, a cGMP-regulated serine-threonine kinase (671 aa) involved in relaxation of vascular smooth muscle and inhibition of platelet aggregation. Type I is soluble, type II is membrane-bound....

G protein‐coupled receptor

G protein‐coupled receptor   Reference library

Oxford Dictionary of Biochemistry and Molecular Biology (2 ed.)

Reference type:
Subject Reference
Current Version:
2008
Subject:
Science and technology, Life Sciences
Length:
107 words

... protein‐coupled receptor ( abbr. : GPCR ) or G protein‐associated receptor or G protein‐linked receptor member of a diverse family of cell‐surface proteins that has adapted a common heptahelical framework to mediate a range of physiological processes (e.g., vision, olfaction, chemotaxis). Their functional diversity is achieved via interactions with a variety of ligands (e.g., peptides, glycoproteins, small molecule messenger molecules, vitamin derivatives), the effects of which stimulate a range of intracellular pathways through coupling to different...

G protein-coupled receptors

G protein-coupled receptors   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
94 words

... protein-coupled receptors ( GPCRs ) integral proteins belonging to a large superfamily of cell-surface receptors, each of which contains 7 membrane-spanning, alpha helix ( q.v .) domains and a bound G protein. GPCRs bind ligands, such as hormones, odorants, growth factors, and neurotransmitters on the cell surface, and transmit signals to the interior of the cell to regulate cell functions such as hormonal regulation, olfactory perception, cell growth, and transmission of nerve impulses. See cellular signal transduction , G proteins , growth factor , ...

G-protein-coupled receptors

G-protein-coupled receptors   Quick reference

A Dictionary of Biomedicine (2 ed.)

Reference type:
Subject Reference
Current Version:
2019

...G-protein-coupled receptors A large family of eukaryotic cell surface receptors (GPCRs, G-protein-linked receptors, GPLR) that are coupled to intracellular heterotrimeric G proteins ( GTP-binding proteins ). All have seven membrane-spanning domains (and are sometimes referred to as serpentine receptors, seven transmembrane-domain receptors, or heptahelical receptors) and high-resolution crystal structure has been obtained for the human β ‎ 2 -adrenergic receptor. Ligand binding induces a conformational change which then activates a G-protein signalling...

G-protein-coupled receptor

G-protein-coupled receptor   Quick reference

A Dictionary of Biology (8 ed.)

Reference type:
Subject Reference
Current Version:
2019
Subject:
Science and technology, Life Sciences
Length:
179 words

...and third intracellular loops and part of the carboxy tail form the binding domain for the G protein. A wide range of substances, including peptide hormones, acetylcholine, adrenaline, noradrenaline, gamma-aminobutyric acid, and glutamate, can bind as ligands to the various types of GPCR, at binding sites in the extracellular region of the receptor molecule. Ligand binding changes the shape of the receptor allowing the G protein to bind to it, which activates the G protein by causing GTP to replace bound...

G-protein-coupled receptor kinases

G-protein-coupled receptor kinases   Quick reference

A Dictionary of Biomedicine (2 ed.)

Reference type:
Subject Reference
Current Version:
2019

...G-protein-coupled receptor kinases A family of kinases involved in down-regulating receptors. GRK1 (rhodopsin kinase) is involved in deactivation of rhodopsin , GRK2 ( β ‎-adrenergic receptor kinase, BARK, Ark1 ) desensitizes β ‎-adrenergic receptors....

G protein

G protein   Reference library

The New Oxford Dictionary for Scientific Writers and Editors (2 ed.)

Reference type:
Subject Reference
Current Version:
2009

... protein (not hyphenated, cap. G) Abbrev. for guanine nucleotide-binding protein. Any of a group of proteins that bind the nucleotide guanosine triphosphate ( GTP ) and act as molecular ‘switches’ in cellular signalling. Large G proteins comprise three dissimilar subunits, denoted α, β, and γ. There are numerous isoforms of each subunit. The large G proteins fall into four main categories, according to the nature of the α subunit: G s (subscript s for ‘stimulatory’); G i (subscript i for ‘inhibitory’), G q (or G q/11 ), and G 12/13 . Specific α subunits...

G-protein-coupled receptor

G-protein-coupled receptor   Reference library

The New Oxford Dictionary for Scientific Writers and Editors (2 ed.)

Reference type:
Subject Reference
Current Version:
2009

...-protein-coupled receptor (note hyphens) Abbrev.: GPCR A cell surface receptor that transfers signals to the cell interior by means of associated G proteins...

G protein

G protein  

Any one of a group of proteins that relay signals in mammalian cells (see signal transduction). They occur on the inner surface of the plasma membrane and transmit signals from receptors on the outer ...
protein G

protein G  

An immunoglobulin-binding protein (60 aa) expressed in group C and G streptococci. Similar to protein A but has a higher affinity for IgG and will bind IgGs from a wider range of species.
G proteins

G proteins   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
127 words

... proteins guanine nucleotide-binding regulatory proteins. They are activated by the binding of a signaling ligand, such as a hormone, to a transmembrane receptor protein. This interaction causes the receptor to change its shape so that it can now react with a G protein. G proteins are heterotrimeric molecules made up of alpha, beta, and gamma chains. G proteins are active when GTP is bound to them and inactive when GDP is present instead. Activated G proteins dissociate from their receptors and activate effector proteins that control the level of second...

G-proteins

G-proteins   Quick reference

A Dictionary of Food and Nutrition (4 ed.)

Reference type:
Subject Reference
Current Version:
2014

...-proteins Guanine nucleotide binding proteins that are activated in response to binding of a hormone or other ligand to a membrane receptor; when activated the bound GDP is displaced by GTP, and the α‐subunit activates another enzyme that produces an intracellular second messenger . The G-protein has GTPase activity and slowly inactivates itself, so terminating the...

protein kinase G

protein kinase G  

Reference type:
Overview Page
(PKG)A member of the AGC kinase family, a cGMP-regulated serine-threonine kinase (671 aa) involved in relaxation of vascular smooth muscle and inhibition of platelet aggregation. Type I is soluble, ...
G protein-coupled receptor

G protein-coupled receptor  

(GPCR)Any of a superfamily of proteins that are located in cell membranes and act as metabotropic receptors, relaying signals from the exterior to the interior of the cell via associated G proteins. ...
methylCpG‐binding protein 2

methylCpG‐binding protein 2   Reference library

Oxford Dictionary of Biochemistry and Molecular Biology (2 ed.)

Reference type:
Subject Reference
Current Version:
2008
Subject:
Science and technology, Life Sciences
Length:
53 words

...protein 2 abbr. : MECP2; a ubiquitously expressed, very abundant nuclear protein (486 amino acids) of human tissues that is associated with 5‐methylcytosine‐rich heterochromatin. It helps recruit histone deacetylases and other proteins. Mutations result in an X‐chromosome‐linked neurodegenerative disorder of girls that starts 6–18 months after birth and is called Rett...

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