Guanine nucleotide-binding protein subunit alpha-13 is a protein that in humans is encoded by the GNA13 gene.[5][6]
The GNA13 gene encodes the G13 G protein alpha subunit. Together with GNA12, these two proteins comprise one of the four classes of heterotrimeric G protein alpha subunits.[7] 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.[8][9]
Active GTP-bound G12 alpha subunit interacts with and activates ARHGEF1,[10][11][12] ARHGEF11,[13][14] and ARHGEF12.[15][16] These ARHGEF proteins function as guanine nucleotide exchange factors for the Rho small GTPases to regulate the actin cytoskeleton.[17]
GNA13 has been shown to interact with AKAP3,[18] RIC8A,[19][20] and Radixin.[21]
Recurrent mutations in this gene have been associated to cases of diffuse large B-cell lymphoma.[22][23]