G beta-gamma complex

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This heterotrimeric G protein is illustrated with its theoretical lipid anchors. GDP is black. Alpha chain is yellow. Beta-gamma complex is blue.

The G beta-gamma complex is a dimeric protein complex composed of the G protein Gβ (beta) and Gγ (gamma) subunits that are closely bound to one another.

Heterotrimeric G protein complexes ( Gαβγ) are formed from Gα, Gβ, and Gγ subunits. Upon activation of a G-protein coupled receptor, the Gβγ complex is released from the Gα subunit, allowing the Gα subunit to function as a messenger in signal transduction.


The normal role of the beta-gamma complex is inhibition of the Gα subunit. However, the free Gβγ complex can act as a signaling molecule itself, by activating other second messengers or by gating ion channels directly.

Examples of Gβγ complex functions include:


GNB1L and GNB2L1 are not considered to be classical G protein beta subunits, as they do not make part of the beta/gamma protein complex and only show sequence similarities with the true Gβ proteins (ref NCBI GeneID: 54584, GeneID: 10399).


  1. ^ GeneGlobe -> GHRH Signaling Retrieved on May 31, 2009

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