Wikia

Psychology Wiki

Changes: Heterotrimeric G protein

Edit

Back to page

(New page: {{Biopsy}} [[Image:G_protein1.png|thumb|This heterotrimeric G protein is illustrated with its theoretical lipid anchors. GDP is black. Alpha chain is yellow. Beta and gamma chains are blue...)
 
m (External links: replacing category per Template:Category redirect)
 
Line 42: Line 42:
 
{{GTPases}}
 
{{GTPases}}
 
[[Category:G proteins|*]]
 
[[Category:G proteins|*]]
[[Category:Membrane biology]]
+
[[Category:Membranes]]
 
[[Category:Peripheral membrane proteins]]
 
[[Category:Peripheral membrane proteins]]
   

Latest revision as of 21:26, November 16, 2010

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)


File:G protein1.png
This heterotrimeric G protein is illustrated with its theoretical lipid anchors. GDP is black. Alpha chain is yellow. Beta and gamma chains are blue.
File:G-Protein.png
3D structure of a heterotrimeric G protein
File:G protein (heterotrimeric).png
An heterotrimeric G protein. GDP is in purple. Alpha chain in orange. Beta chain in blue. Gamma chain in green. An important loop for signal transduction is shown in red (PDB code=1gg2) (more details...)

"G protein" usually refers to the membrane-associated heterotrimeric G proteins, sometimes referred to as the "large" G proteins. These proteins are activated by G protein-coupled receptors and are made up of alpha (α), beta (β) and gamma (γ) subunits.[1]

Alpha subunitsEdit

Gα subunits consist of two domains, the GTPase domain, and the alpha-helical domain. There exist at least 20 different Gα subunits, which are separated into four main families:

Beta-gamma complexEdit

The β and γ subunits are closely bound to one another and are referred to as the beta-gamma complex. The Gβγ complex is released from the Gα subunit after its GDP-GTP exchange.

FunctionEdit

The free Gβγ complex can act as a signaling molecule itself, by activating other second messengers or by gating ion channels directly.

For example, the Gβγ complex, when bound to histamine receptors, can activate phospholipase A2. Gβγ complexes bound to muscarinic acetylcholine receptors, on the other hand, directly open G-protein coupled inward rectifying potassium channels (GIRKs). They can also activate L-type calcium channels, as in H3 receptor pharmacology.

GenesEdit

ReferencesEdit

  1. Hurowitz EH, Melnyk JM, Chen YJ, Kouros-Mehr H, Simon MI, Shizuya H (2000). Genomic characterization of the human heterotrimeric G protein alpha, beta, and gamma subunit genes. DNA Res 7 (2): 111-20.

External linksEdit

Template:GTPases

This page uses Creative Commons Licensed content from Wikipedia (view authors).

Around Wikia's network

Random Wiki