The Heterotrimeric G-proteins are composed of three types of subunit (Gα, Gβ and Gγ) and mediate many cellular signaling processes. The heterotrimeric G-protein subunits interact with G-protein-coupled receptors (GPCRs) at the plasma membrane. Upon GTP binding, Gα-GTP dissociates from the heterotrimer Gαβγ, then Gα and Gβγ act on their effectors. (Adapted from
FBrf0183798,
FBrf0209904 and
PMID:18043707).