GNGT2

Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-T2 is a signalling protein protein that in humans and vertebrates is encoded by the GNGT2 gene. Either GNGT1 or GNGT2 is the gamma subunit of the G_βγ part of transducin (written G(T) or G_t), a heterotrimeric G-protein naturally expressed in vertebrate retina rod and cone cell of the eye, where it is thought to play a crucial role in phototransduction. GNGT2 only occurs in cone cells, and GNGT1 only occurs in rod cells.

As the gamma subunit (G_γ) of three different families of G proteins (G(I)/G_i, G(S)/G_s and G(O)G_o), GNGT2 is expressed in at least 23 tissues and other cell types, including monocytes of the vertebrate innate immune system, where at increased levels it has been shown to be a potential prognostic marker for some types of cancer, including esophageal cancer.

Several transcript variants encoding the GNGT2 protein have been found for the GNGT2 gene. There is evidence for use of multiple polyadenylation sites by this gene.