disease:Defects in GNAT2 are the cause of achromatopsia type 4 (ACHM4) [MIM:139340]. Achromatopsia is an autosomal recessively inherited visual disorder that is present from birth and that features the absence of color discrimination.,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.,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:Retinal rod outer segment.,
Cell projection, cilium, photoreceptor outer segment . Photoreceptor inner segment . Localizes mainly in the outer segment in the dark-adapted state, whereas is translocated to the inner part of the photoreceptors in the light-adapted state. During dark-adapted conditions, in the presence of UNC119 mislocalizes from the outer segment to the inner part of rod photoreceptors which leads to decreased photoreceptor damage caused by light. .
Retinal rod outer segment.