Transducin is a 3-subunit guanine nucleotide-binding protein (G protein) which stimulates the coupling of rhodopsin and cGMP-phoshodiesterase during visual impulses. The transducin alpha subunits in rods and cones are encoded by separate genes. This gene encodes the alpha subunit in rods. This gene is also expressed in other cells, and has been implicated in bitter taste transduction in rat taste cells. Mutations in this gene result in autosomal dominant congenital stationary night blindness. Multiple alternatively spliced variants, encoding the same protein, have been identified. [provided by RefSeq, Feb 2009],disease:Defects in GNAT1 are the cause of congenital stationary night blindness autosomal dominant type 3 (CSNBAD3) [MIM:610444]; also known as congenital stationary night blindness Nougaret type. Congenital stationary night blindness is a non-progressive retinal disorder characterized by impaired night vision.,function:Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. Transducin is an amplifier and one of the transducers of a visual impulse that performs the coupling between rhodopsin and cGMP-phosphodiesterase.,online information:Retina International’s Scientific Newsletter,similarity:Belongs to the G-alpha family. G(i/o/t/z) subfamily.,subunit:G proteins are composed of 3 units; alpha, beta and gamma. The alpha chain contains the guanine nucleotide binding site.,tissue specificity:Rod.,