Guanine nucleotide-binding protein subunit alpha-12 is a protein that in humans is encoded by the GNA12 gene.[5][6][7]
The GNA12 gene encodes the G12 G protein alpha subunit. Together with GNA13, these two proteins comprise one of the four classes of heterotrimeric G protein alpha subunits.[8] Heterotrimeric G proteins function in transducing hormone and neurotransmitter signals detected by cell surface G protein-coupled receptors to intracellular signaling pathways to modulate cell functions. G protein alpha subunits bind to guanine nucleotides and function in a regulatory cycle, and are active when bound to GTP but inactive and associated with the G beta-gamma complex when bound to GDP.[9][10]
Active GTP-bound G12 alpha subunit interacts with and activates ARHGEF1,[11] ARHGEF11,[12][13] and ARHGEF12.[14][15] These ARHGEF proteins function as guanine nucleotide exchange factors for the Rho small GTPases to regulate the actin cytoskeleton.[16]
GNA12 also interacts with PPP5C,[17] HSP90,[18] Resistance to inhibitors of cholinesterase-8A (Ric-8A)[19] and TEC.[15]