Gs alpha subunit (Gsα)

The Gs alpha subunit is a component of heterotrimeric G proteins that couples hormone and neurotransmitter receptors (GPCRs) to adenylyl cyclase activation[3]. When activated (normally by GPCRs via GTP loading, or pathologically by ADP-ribosylation from toxins such as cholera toxin), Gsα stimulates adenylyl cyclase to produce cyclic AMP (cAMP), a second messenger that regulates diverse cellular processes. ADP-ribosylation of Gsα locks the protein in its active, GTP-bound form, resulting in persistent cAMP production and downstream effects[2][8]. This mechanism is exploited by bacterial toxins (notably cholera toxin) to cause pathophysiological conditions such as secretory diarrhea. Gsα is encoded by the GNAS gene in humans and is involved in numerous physiological and pathological pathways, including those related to cardiovascular, metabolic, and endocrine functions[3][5][7].

Other names

Gs alpha subunitGNAS proteinGαsStimulatory G protein alpha subunitGuanine nucleotide-binding protein Gs alpha subunit

ADP-ribosylation (by cholera toxin and similar toxins which irreversibly activate Gsα); GTP/GDP exchange (reversible activation via normal GPCR agonist stimulation)