G protein stimulatory alpha subunit (Gs alpha) (Gsα)

The G protein stimulatory alpha subunit (Gs alpha) is a key component in G protein-coupled receptor signaling, mediating the activation of adenylate cyclase in response to hormone or neurotransmitter binding on GPCRs. When ADP-ribosylated by toxins such as cholera toxin, Gs alpha dissociates from its beta and gamma subunits and remains active, causing persistent activation of adenylate cyclase and elevated intracellular cAMP. This molecular event underlies the pathophysiology of certain bacterial toxin actions and is a critical point in signal transduction for numerous physiological processes.

Other names

Stimulatory G protein alpha subunitGs alphaGNAS

Irreversible ADP-ribosylation of Gs alpha by cholera toxin leads to continuous activation of adenylate cyclase. GPCR agonists cause exchange of GDP for GTP on Gs alpha, activating adenylate cyclase (physiological mechanism)