The function of Ensembl gene identifier ENSG00000114349 (GNAT1, G protein subunit alpha transducin 1) is as follows. Alpha subunit of the heterotrimeric guanine nucleotide- binding protein (G protein) that transduces signals from the G protein- coupled photoreceptor rhodopsin (RHO). Required for normal RHO-mediated light perception in retinal rod photoreceptors (PubMed:22190596). Functions as a GTPase that contains the guanine nucleotide binding site and cycles between an active GTP-bound state and an inactive GDP-bound state. Under dim light conditions, RHO promotes GDP release and GTP binding. Activates downstream effectors, including cone cGMP- phosphodiesterase (PDE6), to mediate the phototransduction cascade (By similarity). Stimulates PDE6 by binding and repositioning the PDE6 gamma inhibitory subunits (PDE6G) to promote catalytic activity (By similarity). {ECO:0000250|UniProtKB:P04695, ECO:0000269|PubMed:22190596}.