G_{α i-1} (I-20) Antibody: sc-391

G_{α i-1} Background Information
Heterotrimeric G proteins function to relay information from cell surface receptors to intracellular effectors. Each of a very broad range of receptors specifically detects an extracellular stimulus (a photon, pheromone, odorant, hormone or neurotransmitter), whereas the effectors (i.e. adenyl cyclase), which act to generate one or more intracellular messengers, are less numerous. In mammals, G protein a, b and g subunits are encoded by at least sixteen, four and seven different genes, respectively. The a subunits bind to and hydrolyze GTP. G protein complexes expressed in different tissues contain distinct a, b and g subunits. Preferential associations between members of subunit families increase G protein functional diversity. Most interest in G proteins has been focused on their å subunits, since these proteins bind and hydrolyze GTP and most obviously regulate the activity of the best studied effectors. Four distinct classes of Gå subunits have been identified; these include Gs, Gi, Gq and Ga 12/13. The Gi class comprises all the known a subunits that are susceptible to pertussis toxin modifications, including Gå i-1, Gå i-2, Gå i-3, Gå o, Gå t1, Gå t2, Gå z and Gå gust. Of these, the three Ga i subtypes function to open atrial potassium channels.