Purified Mouse Anti-Gαs

Guanine nuceotide binding proteins (G proteins) are composed of three subunits, alpha, beta, and gamma to form a trimer complex.  Together these proteins act as signal transducers for a large number of G-protein linked receptors including neurotransmitters, hormones, and signaling molecules.  Ligand binding to the  G-protein linked receptor triggers the release of GDP from the alpha subunit, allowing GTP to bind, dissociating the beta/gamma complex.  The G alpha subunit (G alpha s) is free to bind to other molecules; it is also a GTPase which hydrolyzes the bound GTP to GDP.  Following hydrolysis, the G alpha molecule re-forms as a trimer complex with G beta/gamma. Thus, G proteins can act as a switch, active when bound to GTP, and inactive when bound to GDP.  Cloning of the G alpha protein revealed that it was alternatively spliced into an alpha1 and alpha2 versions.